The Constitutional Issues Raised by City of London versus Samede Essay

The Constitutional Issues Raised by City of London versus Samede [2012] EWHC 34 (QB) - Essay Example The counsels for the claimant were David Forsdick and Zoe Leventhal (instructed by Andrew Colvin, the Comptroller and City Solicitor, City of London Corporation) while John Cooper QC and Michael Paget (instructed by Kaim Todner) were Samede’s counsels (Practical Law Publishing Limited, P. 1). The City of London Corporation made claims before the Royal Court that the said protestors had possessed and turned into a protest camp, the highway and the Churchyard at the St. Paul Cathedral. In the claim, the City of London Corporation also sought an injunction ordering that the tents and other structures erected at the said site by the protestors be removed (DeLaney, P. 7). The City of London thus claimed authority of the campsite and the surrounding land, citing various Acts of Parliament such as the Town and Country Planning Act 1990, the Local Government Act 1972 and the Local Government Act 2000. There are numerous constitutional issues touching on the defendants and the claimant that arose in the Samede versus City of London Corporation (2012), some of which this paper explores. The Constitutional Issues in the Case The scope of the claim placed by the City of London Corporation covered two types of land: the highway and the open land under St. Paul’s Cathedral’s ownership. ... Among the constitutional issues that were immediately identified in the case was whether the City of London Corporation had established beyond reasonable doubt that it was entitled to possess the land under question (DeLaney, P. 5). In this regard therefore, upon considering any chances of interfering with the rights of the protestors (defendants), the Court would not err in granting the City of London the possession of the highway land. That is, the court had to ensure that granting the City of London possession of the land would not only be lawful but also necessary and proportionate (Practical Law Publishing Limited, P. 23). Central in the City of London versus Samede and others (2012) were the various relevant statutory laws and powers that govern possession and injunctive relief. First, these statutory powers mandate local highway authorities to ensure the protection of the rights of the public to use and enjoy the highway and all the services it offers. According to section 130 (5) of the 1980 Act, and under section 222 of the 1972 Act, such an authority may institute any legal proceedings against an individual or groups that interfere with the public’s rights and freedom to enjoy and use such a facility. Human Rights Issues Human rights issues also featured prominently in the City of London versus Samede and others case. Among these human rights issues are rights and freedom of religion, thought and conscience, as provided for in Article 9 of the European Convention on Human Rights (Folsom, P. 67). In other words, every citizen or community has the right and the freedom to change religion and practise it in public or in private, alone or with others. In addition, there is freedom and right to manifest one’s religion through means such

To research a business opportunity for an American product (Clothing & Paper

To a business opportunity for an American product (Clothing & Apparel) in Morocco - Research Paper Example In this analysis the Moroccan trade policies in terms of Foreign Direct Investment (FDI) along with the integration of participation in regional economic structures. Notably, Moroccan market witnessed a new phase of its foreign trade relationship when the economic policies were reassessed and FDI flow was liberalized in the year 2005, rendering opportunities for a new business entering in the markets of Morocco from a foreign state. The economy also intended to execute certain programs which would facilitate the growth of industrial sector and thus benefited the new entrants to the economy (United States Agency for International Development, â€Å"Morocco New Business Opportunities Program†). ... For instance Morocco is known to be an Islamic nation. Similar to other majority of Islamic nations, the business environment of Morocco is highly influenced by the religious beliefs of the nation which might create certain challenges for the American Clothing & Apparel Company. Notably, King Mohammed VI, the pre-eminent authority of the political systems of Morocco, declared to build a democracy and granted limited executive power to the Prime Minister of the country in the year 2011. This facilitates a significant change in the economic structure of the nation developing it as a ‘Unitary parliamentary democracy and Constitutional Monarchy’ (Arieff, â€Å"Morocco: Current Issues†). Economic System According to the World Bank, the economic status of Morocco is often regarded as a Lower-Middle-Income (LMI) country. The Free Trade Agreement (FTA) with the United States was conducted by the government of Morocco in the year 2006 indicating the objective of the econom y to enhance the trade relationship between the two nations, i.e. Morocco and US (United States Agency for International Development, â€Å"Morocco New Business Opportunities Program†). It is worth mentioning that in the current economic regimes of Morocco, Foreign Direct Investment (FDI) is considered as an important tool for its overall development. It is also regarded as a major indicator of the efficiency of those policies and incentives implemented toward investment activities undertaken by Morocco. Based on this notion, the economic trade policies within Morocco have been developed to facilitate the trade relationships on the international ground enhancing the business opportunities within the nation (PKF, â€Å"Doing business in Morocco†). It is in this context that the continuous

Effective team performance Essay Example | Topics and Well Written Essays - 2250 words

Effective team performance - Essay Example During the project, as the team progressed through its four development stages described by Tuckman’s model (Beyerlein and Johnson 2000) many problems and conflicts surfaced, not beyond expectations. Although problems addressed as the team developed more collaboration, communication and understanding of team objectives, these could have been avoided (Kayes 2004). During the project, engagement of group in different activities discussed helped developing a cohesive team. This project report primarily aims to elaborate significance of reflection in learning and analyses transformation of experiences into learning process (Kolbs 1984). Also this report describes the process of development of a group into a team, associated problems, and narrates the key role of different concepts and theories. Soon after group formation, I was skeptical about the group future, team development, team interactions and achievement of desired objectives. Beyerlein and Johnson (2000) view it as initial stage of team forming based on Bruce Tuckman Model where group members develop understanding among them. According to McManus (2000), teams exhibit a strong commitment, high degree of cohesiveness and accomplishment towards common goal than groups. Chaney and Lyden (2000) advocate teamwork for improvement in problem solving, decision-making and communications. During the initial stage of group formation, members were not focused towards team objectives rather were busy in their personal and social issue. Even they were neither in knowledge nor prepared for meetings agenda items. Team members being less organized and non-interactive were shy and reluctant to share knowledge and experience. These issues introduced hurdles in task completion, team development, cohesion and improving collaboration. Task sequencing and interdependencies caused problems when the completion of one job depended upon input from another

Target Group Analysis for Marketing Report Essay

Target Group Analysis for Marketing Report - Essay Example It is JetNet Services' goal to enable their clients to a professional positioning in the Internet which is the main access to information and communication of nowadays and the future - together with providing all support necessary in case the client wishes to purchase optimally suited hard- and software. There are four business units, offering their services and products for four different purposes but having the same management and exchanging information within the company. The advantages of this for the client are short communication paths; one contact person who manages all the contacts in the company (i.e. A case manager) and a range of in-house services and products. Research suggests that the four units do not actually have separate targets. There are primarily two broad targets: Internet Unit and IT Support Unit; Graphic Unit and Multi-media Unit targets. These groups have enough overlap that they may be broadly looked at in a similar light. There is also a primary target for all four units as a package. The first section describes the Internet-Business Unit and IT Support Unit. However, there is some overlap of target markets for the other 3 business units (graphic design, multimedia, IT-Consulting). Two main target groups exist for the Internet and It_support Units. (Shurmer 1993, p. 240) Small and middle enterprises without their own marketing departments broadly comprise the first group. The two primary sub groups of this section are differentiated by the demographic information of their business leader. Young entrepreneurs heading start-up companies are the first of these leaders. The young entrepreneur is aged 20-35 years old, and is early on in his career. The second sub-group leader is an older entrepreneur, aged 36-55 years, with an established career, and a firmly entrenched company. (Igel 2001, p.159) Small and middle enterprises with their own in-house marketing and/or technical support departments make up the second broad group. Within this category, there are also two sub groups based on the demographic information of the decision maker. Here, the first target is the marketing manager: he is typically male and manages the entire marketing department. The second is the marketing assistant: most often female and reporting directly to the marketing manager. 2.1 Young startup entrepreneur The young entrepreneur is aged 25-35 and has just founded a company. He needs professional services for designing and implementing his company's website. A website is a must have for him because several start-up consultancies recommended creating a website as the first step in marketing a new business, followed by purchasing professional stationary and business cards for Corporate Design/ Corporate Identity purposes. The young entrepreneur grew up using the Web and he is competent in the technical skills involved in using the Internet for business and personal matters (i.e. knows how to browse the Internet, search Goggle, and send email) and he also is open to the technology and knows the marketing benefits that the Web offers (such as being a cheap marketing platform, up to date information, and reaching a wide audience). (Trondsen 1996, p.571) 2.1.1 Older entrepreneur The older entrepreneur

The percentage energy loss when a ball Bounces Essay Example for Free

The percentage energy loss when a ball Bounces Essay This investigation will be to determine the relationship between the length of a conductor and its resistance. The aim is to test a number of different lengths of nichrome wire to measure the resistance of each length. To ensure a safe procedure, a low voltage battery of 12 volts will be used, and the samples to be tested will be located on an insulating mat to prevent any shorts occurring. In addition a 2 Amp fuse will be placed in the circuit as a protective measure. For a fair test, all other parameters that can affect the resistance will be kept constant. These are the sample material, the diameter of the wire, and the temperature of the wire. To keep the temperature of the wire constant, it will be necessary to keep the current flowing in it constant. This is because the power dissipated in the conductor is I2R, so an increase of current by a factor of 2 will increase the power dissipated by a factor of 4, which can seriously affect the resistance. Thus only the length of the wire will be changed, and the corresponding voltage across it to give the same test current will be varied and measured. The resistance of the test sample will then be given by Ohms Law: Resistance = Voltage (Volts) ( Ohm) My prediction is that the resistance of the wire will be proportional to its length, all other variables being kept constant Equipment The equipment used for this investigation consisted of: 1) 12 volt power pack with on/off switch 2) Variable resistor (rheostat) 3) A 2 amp ammeter with digital readout to 0. 001 amp accuracy 4) A 20V voltmeter with digital readout to 0. 01V accuracy 5) Crocodile clips for connection of the test sample into the circuit and the voltmeter to the connecting crocodile clips. 6) Test samples consisting of varying lengths of 24 SWG The equipment and the circuit configuration used is shown in Fig 1. A 12-volt power pack will be connected in series with a switch, a 2-amp fuse, an Ammeter, a variable resistor and a sample test wire. A voltmeter will be connected across the test sample by crocodile clips. The test sample was connected into the circuit using crocodile clips. The voltmeter was connected across the sample into the rear of the crocodile clips. The plan will be to vary the sample length from 10 cms to 100 cms in 10 cm increments to provide a good range of results. Also to take readings of three samples for each length, and average the voltage readings to reduce possible errors. There are four factors that will affect the resistance of a wire. These are: 1. As the length of a wire increases, the resistance of the wire also increases. A variable resistor or rheostat is used to vary the current in a circuit. As the sliding contact moves, it varies the length of wire in the circuit. 2. As the cross-sectional area of a wire increases, the resistance of the wire decreases. An analogy of this is a water pipe, if the diameter of the water pipe is small the water flowing through will. Experience high resistance to the rate of flow. However if the diameter of the water pipe is large, the water flowing. Through it will experience low resistance to the rate of flow. 3. Different types of materials will affect the resistance in different ways. Materials such as copper, are very good conductors, and is used for connecting wires. Other materials such as nichrome (as used in the investigation) have a higher resistance than copper, and so is used in the heating elements of electric fires. 4. As the temperatures of a wire increases, the resistance of the wire increases as well. This is used in resistance thermometers, which use the fact that electricity does not flow so easily through a wire when the wire gets hot. Resistance is the opposition to the flow of charge. In metals, a sea of free electrons enabling it to conduct electricity surrounds a lattice of positive ions. The shorter the length of wire, the less energy is needed to move the electrons across the wire If the metal is attached to a power supply then the electrons flow through the metal but collide with atoms. Resistance is shown below in the diagram below: The resistance of a metal can be regarded as arising from the interaction, which occurs between the crystal lattice of the metal and the free electrons as they drift through it under an applied potential difference. This interaction is due mainly to collisions between defects in the crystal lattice (e. g. impurity atoms and dislocations) also play a part, especially at very low temperatures. Resistance is measured in Ohms (? ) Georg Ohm discovered that the current flowing through a metal wire is proportional to the potential difference across it (providing the temperature remains constant). Therefore: Resistance, R (? ) = Potential difference across the wire (V) I= V i R V= I x R R= V i I TABLE 1 RESULTS: Table 1 shows the data recorded and the resulting values for resistance for each length. These were those separate samples of the conductor tested for each length, and the average voltage was used to determine the resistance volume. Graph 1 plots the resistance against length for the range of test samples from 10cm to 100cm. The graph shows the data to be in very close proximity to a straight line, verifying the prediction to its length. From the best fit line drawn on the graph, the resistance per unit length of 24 SWG nichrome wire is found to be 0. 362 ohm/cm. When current passes down a wire, the wire gets heated. The moving electrons collide with ion and cause them to vibrate thus increasing the temperature ths is a waste of energy-when a current flows, heat is transferred to the air surroundingggs which explains why computers get hot in operation. However we can make use of the heating effect e. g. in fuses which are designed to melt when too much current flows e. g. in kettles. We can calculate the heat transferred per second using the following formula: Power = (Current)2 x Resistance (Watts) = (Amps)2 x (Ohms) (W) = (A)2 x (? ) Length (cm) Current (Amps) Resistance in Ohms (R=V/I) Power (Watts) From the table above we see that there is a relationship between the resistance and the current. We see that from the results table that the power (in Watts) is equivalent to the current (in amps) squared multiplied by the resistance of the wire. From the graph showing Power Vs Length, we can work out the heat transferred in one centimetre of nichrome wire. Power i Length =Thermal energy transferred (J) Length (cm). Current (Amps) Power (Watts)Â   From these results we can work out the coulombs of charge in each separate length of nichrome. This result will then allow us to calculate how many electrons had passed through the wire, which further allows us to calculate the time taken for the experiment to take place.

Control system for microgrid

Control system for microgrid Abstract In this study an example of a microgrid composed of diesel generator and two uninterruptable power supply systems is considered. This microgrid installed in the three buildings of the Tallinn University of Technology. This paper deals with how to implement a distributed control and monitoring system based on the Ethernet network in the microgrid. The paper describes a control strategy to implement both grid connected and islanded operation modes of the microgrid. Keywords Control system, diesel generator, microgrid Introduction Distributed generation (DG) is becoming an increasingly attractive approach to reduce greenhouse gas emissions, to improve power system efficiency and reliability, and to relieve todays stress on power transmission and distribution infrastructure [1]. Distributed generation encompasses a wide range of prime mover technologies, such as internal combustion engines, gas turbines, microturbines, photovoltaic, fuel cells and windpower [32]. A better way to realize the emerging potential of DG is to take a system approach which views generation and associated loads as a microgrid [21]. Microgrid is a concept of defining the operation of distributed generation, in which different microsources operate as s single controllable system that provides power and heat to a cluster of loads in the local area [3], [8] [9]. A well designed microgrid should appear as an independent power system meeting the power quality and reliability requirements [3]. The primary goal of microgrid architectures is to significantly improve energy production and delivery to load customers, while facilitating a more stable electrical infrastructure with a measurable reduction in environmental emissions [10]. The most positive features of microgrids are the relatively short distances between generation and loads and low generation and distribution voltage level. The main function of a microgrid is to ensure stable operation during faults and various network disturbances. The microgrid is a promising concept in several fronts because it [18]: provides means to modernize todays power grids by making it more reliable, secure, efficient, and de-centralized; provides systematic approaches to utilize diverse and distributed energy sources for distributed generation; provides uninterruptible power supply functions; minimizes emissions and system losses. Despite many advantages of microgrid there remain many technical challenges and difficulties in this new power industry area. One of them is the design, acceptance, and availability of low-cost technologies for installing and using microgrids [4]. The increased deployment of power electronic devices in alternative energy sources within microgrids requires effective monitoring and control systems for safe and stable operation while achieving optimal utilization of different energy sources [35]. Microgeneration suffers from lack of experience, regulations and norms. Because of specific characteristics of microgrids, such as high implication of control components, large number of microsources with power electronic interfaces remains many difficulties in controlling of microgrids. Realization of complicated controlling processes in microgrids requires specific communication infrastructure and protocols. During the process of microgrid organization many questions concerning the protection and safety aspects emerge. Also, it is required to organize free access to the network and efficient allocation of network costs. The predominant existing distributed generation is based on an internal combustion engine driving an electric generator [36]. To investigate various aspects of integration of alternative energy sources such as conventional engine generators, this paper proposes a prototype of the microgrid for three academic buildings at the Tallinn University of Technology which consists of a diesel generator, and batteries storage with power electronic interface. The main goal of this work is to design an intelligent control system of the microgrid that is efficient enough to manage itself for power balance by making use of state of the art communication technology. Moreover, the aim of this paper is to describe the control strategy of the microgrid operation in both stagy state modes. This control system enables the microgrid system to balance the electric power demand and supply and to simultaneously control the state of power network. Microgrid Theoretical Background A microgrid is described as a small (several MW or less in scale) power system with three primary components: distributed generators with optional storage capacity, autonomous load centers, and system capability to operate interconnected with or islanded from the larger utility electrical grid [10], [11]-[13]. According to [39], [22], multiple facility microgrids span multiple buildings or structures, with loads typically ranging between 2MW and 5MW. Examples include campuses (medical, academic, municipal, etc), military bases, industrial and commercial complexes, and building residential developments. Microgrids include several basic components for operation [3], [4]. An example of a microgrid with is illustrated in Fig.1. Distributed Generation Distributed generation units [1] are small sources of energy located at or near the point of use. There are two basic classes of microsources; one is a DC source (fuel cells, photovoltaic cells, etc.), the other is a high frequency AC source (microturbines, reciprocating engine generators, wind generators), which needs to be rectified. An AC microgrid can be a single-phase or a three-phase system. It can be connected to low voltage or medium voltage power distribution networks. Storage Devices Distributed storage technologies are used in microgrid applications where the generation and loads of the microgrid cannot be exactly matched. Distributed storage provides a bridge in meeting the power and energy requirements of the microgrid. Distributed storage enhances microgrid systems overall performance in three ways. First, it stabilizes and permits DG units to run at a constant and stable output, despite load fluctuations. Second, it provides the ride through capability when there are dynamic variations of primary energy (such as those of sun, wind, and hydropower sources). Third, it permits DG to seamlessly operate as a dispatchable unit. Moreover, energy storage can benefit power systems by damping peak surges in electricity demand, countering momentary power disturbances, providing outage ridethrough while backup generators respond, and reserving energy for future demand. There are several forms of energy storage, such as the batteries, supercapacitors, and flywheels. Interconnection Switch The interconnection switch is the point of connection between the microgrid and the rest of the distribution system. New technologies in this area consolidate the various power and switching functions (power switching, protective relaying, metering, and communications) traditionally provided by relays, hardware, and other components at the utility interface into a single system with a digital signal processor. The interconnection switches are designed to meet grid interconnection standards. Control System The control system of a microgrid is designed to safely operate the system in grid-parallel and stand-alone modes. This system may be based on a central controller or imbedded as autonomous parts of each distributed generator. When the utility is disconnected, the control system must control the local voltage and frequency, provide (or absorb) the instantaneous real power difference between generation and loads, provide the difference between generated reactive power and the actual reactive power consumed by the load, and protect the internal microgrid. Structure of the Proposed Microgrid The microgrid installed in three buildings of the Tallinn University of Technology (TUT): Faculty of Power Engineering, TUT Library, School of Economics and Business Administration. Consequently, according to the classification given in [22], this power system can be defined as a multiple facility microgrid. Fig.2 illustrates the various components of the power system of the microgrid at TUT. The structure of the microgtid for the campuses of the TUT is proposed. Fig.3 shows a schematic of the power system. Microgrid systems targeted in this study are autonomous areas having the power demand of several kilowatts including a diesel generator, two uninterruptable power supply (UPS) systems with batteries storage, and loads. They are connected to the power electronic interface forming local AC network with 230V, 50Hz. The diesel generator is used as the main distributed energy resource in this microgrid. It has a nominal power of 176kW/220kVA, voltage of 240V/400V and maximum current of 318A. This generator is connected to the AC bus via the automatic relay logic (ARL2). The ARL2 is continuously observing it both sides: the main grid and the microgrid. If there is a fault in the general grid, the ARL2 will disconnect the microgrid, creating an energetic island. The battery banks (E1 and E2) are used as the distributed energy storage devices in the microgrid to insure continuous supply of the local load. They are interfaced to the electrical network through the two UPS systems: UPS1 (160kVA), and UPS2 (240kVA). Hence, we can conclude that the microgrid has two main possible operation modes: grid-connected and islanded mode. Main customers of the microgrid are the computers and servers located in the laboratories and office rooms in the three buildings of TUT. The clients in the Library Building (computers) are interfaced to the electrical network using ARL1. In addition, four experimental loads (Experimental loads 1..4) are used that can be connected to the distributed shield located in the Laboratory of Electrical Drives. The nine intelligent sensors (P1..P9) assign these loads. Their task is to measure electrical power and energy parameters of the network, such as voltage, current, power, energy, power factor and transmit this information to the controller. The microgrid is connected to the general city electricity grid using two two-section transformer substations (6000kV/400kV) located in the Faculty of Power Engineering and the School of Economics and Business Administration Buildings. Description of the Control System Taking into account the configuration and features of the power network of the Tallinn University of Technology, the control system structure for the microgrid is designed with the following specifications: the balance of electric power demand and supply of power network are provided; both the steady state modes and the transient performance of the microgrid are achieved. A block diagram of the hierarchical control system which is based on the multiagent technology [40], [41], is demonstrated in Fig.4. The design of the control system can be divided into hardware and software. The control structure of the microgrid has three levels: Operator console and application server; Central controller (CC); Local controllers (LC) and measuring devices. Operator console is a computerized workstation with special software which comprises of supply and demand calculation units, monitoring units, control schemes and dispatching units. The function block diagram of the software is shown in Fig.5. The operator console heads the hierarchical control system. Its main goals of are: to keep track of the whole system by monitoring the status of the communication nodes and generating units; to collect data from the measuring devices; to calculate supply and demand of power; to visualize information received; to display the basic modes of the microgrid; and to transfer control commands to the central controller. Application server is designed for archiving data received from the measuring devices. The main interface between the operator console and others communication nodes of the microgrid control system is the central controller. It is the main responsible for the management of the microgrid. for the optimization of the microgrid operation. The central controller operates in real time. Its main functions are: connection and disconnection of the microgrid, the synchronization process, the detachment of loads. In addition, the aims of the central controller are: to collect information from the measuring devices; to transfer data from the operator console and the application server; to manage the power supply switches; and to transmit the control commands to the local controllers. Group of the local controllers are related to the third hierarchical control level. They include microsource controller that located in the distributed resources of the microgrid. It manages active and reactive power production levels at the diesel generator. Moreover, the microsource controller is responsible for the maintaining desired steady-state and dynamic performance of the power network. The other local controllers are located in the two UPS systems. Their main goals are to provide management of charge of the batteries storage. Measuring process Information required by the proposed monitoring and control system is voltage, current, power, energy, and power factor measurements. Real-time information is acquired through the intelligent measuring devices located at the output of the energy source, at the input of each loads, and at the both UPS systems. In this system, Allen-Bradley Powermonitor 3000 [25] is used to measure these instantaneous values. It implements real-time power monitoring with 50 ms selectable update rate. Such operating information is displayed in real-time for monitoring and energy management purposes. Communication network A communication infrastructure is needed between the central controller and the local controllers [23]. The short geographical span of the microgrid may aid establishing a communication infrastructure using low-cost communications. The adoption of standard protocols and open technologies allows designing and developing modular solutions using off-the-shelf, low-cost, widely available, and fully supported hardware and software components. At the present time, many low cost microcontrollers include at least an Ethernet controller, standalone cheap controllers are also available. The main advantages of using Ethernet are: the transition from a centralized control to a distributed control; wiring reduction no need for point to point connections. This solution provides flexibility and scalability for low-cost implementations. Taking these into account, the Ethernet industrial protocol has been chosen in this microgrid as communication network for data transfer for all those control units. The amount of data to be exchanged between network controllers includes mainly messages containing set-points to LC, information requests sent by the MGCC to LC about active and reactive powers, and voltage levels and messages to control microgrid switches. The LC is responsible of collecting local information from the attached energy resource and takes some real-time decisions based on the control algorithm. The communication network of the control system is illustrated in Fig.6. Every communication node has to get registered to the master server. The node sends its information to the master server through diverse communication channel. Furthermore, this topology provides an opportunity for immediate control center access via remote consoles and web based laptops for necessary actions to be taken. To include new generation resources or storage devices in a flexible manner into the microgrid, multi-agent technologies [40] might be applied. The proposed hierarchical control scheme provides a flexible platform to make high level decisions. Control Strategy of Operation of the Microgrid A microgrid may operate either connected to the main grid or disconnected from it. There are two steady states of operation, grid-connected (Mode-G) and islanded (Mode-I). Furthermore, there are two transient modes of operation, transfer from Mode-G to Mode-I and transfer from Mode-I to Mode-G. The key issue of the control is how to maintain the voltage and frequency stability of the microgrid [20]. Grid-connected mode In the grid-connected operation mode, the main function of a DG unit is to control the output real and reactive power. The real and reactive power generated by a DG can be controlled through current or voltage regulation, thus the DG output power control schemes can be generally categorized as current-based and voltage-based power flow control [43]. During Mode-G operation, the voltage and frequency of the microgrid is set by the main grid. The aim of the uninterruptible power supply systems is to obtain energy backup as much as possible, so during Mode-G operation, the main grid, the microgrid or both of them, will charge the batteries [20]. In grid-connected mode the balance between the generation and the consumption as well as the control of the parameters of the system is guaranteed by the utility grid. Thus, generators are regulated with the criterion of optimized economic exploitation of the installation [23]. Concerning the programmable generator, the objective of the control is to optimize the microgrid performance. Islanded mode The MG operates autonomously, in a similar way to physical islands, when the disconnection from the main grid occurs [37]. When the grid is not present, the ARL2 disconnects the microgrid from the grid, starting the autonomous operation. The instant at which the intentional islanding occurs must be detected in order to the inverter changes between grid-connected to intentional island modes. The detection is achieved using an algorithm described in [23]. When the main distribution network is faulted, the fault current will flow into the main grid from the microgrid continuously. At the same time, the circuit breaker of microgrid should detect the frequency and voltage-drop, and open in time, which makes the microgrid disconnect automatically from the main grid and change to islanded operation mode. Diesel generator should adopt the reasonable control strategies to ensure the stability of frequency and voltage in microgrid [42]. While switched from Mode-G to Mode-I, the UPS system operates in voltage control mode, is setting the voltage and frequency of the microgrid through absorbing or releasing energy. In islanded mode, due to the unavailability of the utility grid, two requirements must be fulfilled: the power balance between the generation and the consumption and the control of the main parameters of the installation (voltage amplitude and frequency). In synchronous islanded mode this reference is the same as the grid voltage. This mode is also called synchronization mode and it is the mode that necessarily precedes a reconnection with the grid. The control system is responsible for assuring the power balance. In case of energy excess the management system can limit the output power of the diesel generators power in order to avoid the operation in extremely inefficient low power generation modes. On the contrary, if all the available power is not enough to feed the local loads, the management system will detach non-critical loads. The control system is voltage controlled and it regulates the main parameters of the system. The UPS systems sets the voltage and frequency of the islanded microgrid and maintains them within acceptable limits by injecting or absorbing active power and reactive power as required. As soon as the presence of mains is detected, the microgrid control system uses feedback information from the mains voltage to adjust the energy storage unit voltage and frequency control loops to synchronize the microgrid voltage with the main voltage of the main grid. Transition from Grid-Connected to Islanded Mode There are various islanding detection methods proposed for DG systems [44]. As mentioned above, there is a different control strategy when the laboratory-scale microgrid system operates in Mode-G or Mode-I. If there is a transition between these two modes, the control mode of the battery inverter will change. A switching circuit, as shown in Fig.7, is designed to realize this transition [20]. A load-voltage control strategy proposed by [23] is employed to provide the operation of the microgrid. Disconnection of the microgrid from the grid can be provoked by many causes, like unsatisfactory grid voltage (in terms of amplitude or waveform) or even economic aspects related to power price. In order to monitor grid voltage characteristics a Voltage monitoring module is required. This module measures continuously the rms grid voltage comparing it with a preestablished threshold value. When any of the phase voltages goes down the threshold value (0.9 pu in this case) the detection signal is activated. If 20 ms after the first detection this signal is still activated the microgrid must be disconnected from the utility grid and it must pass to islanded operation mode, otherwise the microgrid will remain connected to the utility grid. This way unnecessary islandings are avoided and selectivity is respected. A 20 ms time window has been chosen after verifying through experimental tests and standards [47] that a personal computer (which is considered as the most critical residential lo ad in this microgrid) is not affected by a 20 ms voltage interruption. As soon as the microgrid is disconnected from the grid, the programmable generator controller passes from a power control mode to a voltage control mode. Microgrid power consumption is also continuously measured in order to detach non-critical loads if there is no enough local available power. In addition if consumption or generation conditions are modified and it becomes possible to feed all the local loads, non-critical loads will be reconnected. Transition from Islanded to Grid-Connected Mode When the grid-disconnection cause disappears, the transition from islanded to grid-connected mode can be started. To avoid hard transients in the reconnection, the diesel generator has to be synchronized with the grid voltage [23]. The DG is operated in synchronous island mode until both systems are synchronized. Once the voltage in the DG is synchronized with the utility voltage, the DG is reconnected to the grid and the controller will pass from voltage control mode to current control mode. When the microgrid is working in islanded mode, and the ARL2 detects that the voltage outside the microgrid (in the grid) is stable and fault-free, we have to resynchronize the microgrid to the frequency, amplitude and phase of the grid, in order to reconnect seamlessly the microgrid. If the grid-disconnection cause disappears and the gridvoltage fulfills the desired requirements, the transition from islanded to grid-connected mode can be started. The grid voltage conditions will be again monitored by the Voltage monitoring module. This way if the grid voltage exceeds the threshold value the detection signal is deactivated. If 20 ms after the first detection the detection signal is still deactivated it means that utility grid has returned back to normal operating conditions and the microgrid can reconnect to the grid. However, before the reconnection, the microgrid has to be synchronized with the grid voltage in order to avoid hard transients in the reconnection. To do so, the microgrid operates in synchronous islanded mode during 100 ms with the aim of decoupling the reference variation and the physical grid reconnection transients. In this operating mode the voltage in the microgrid is set to the characteristics of the grid voltage, frequency and phase. Once the voltage in the microgrid is synchronized with the utility voltage the microgrid can be reconnected to the grid and the programmable generator controller will pass from a voltage control mode to a power control mode. In the same way if non-critical loads are detached they are also reconnected. In the presence of unplanned events like faults, microgrid separation from the MV network must occur as fast as possible. However, the switching transient will have great impact on microgrid dynamics. The microgrid functionalities as well as its control methods depend on the mode of operation [23]: Islanding of the MG can take place by unplanned events like faults in the MVnetwork or by planned actions like maintenance requirements. In this case, the local generation profile of theMG can be modified in order to reduce the imbalance between local load and generation and reduce the disconnection transient [48]. Conclusions In this paper the microgrid system installed at the Tallinn University of Technology, has been presented. The microgrid includes a diesel generator, batteries storage with power electronic interface. The architecture of the microgrid for the Tallinn University of Technology and a control system structure for the microgrid were proposed. Design of a control and monitoring system for a microgrid is presented in this paper. A hierarchical control scheme is proposed. This will enhance the reliability and stability of the microgrid on one end and will make microgrid an easy to use product on the other. Acknowledgement This paper was supported by the Project DAR8130 Doctoral School of Energy and Geotechnology II. References A.M.Borbely,J.F.Krieder, Distributed generation: the power paradigm for the new millennium, CRC Press, Boca Raton, Florida, 2001, 388p. P.Nabuurs, SmartGrids, European Technology platform, Strategic Deployment Document for Europes Electricity Networks of the Future, September 2008, 68p. R.Lasseter, Microgrids, Proceedings of 2002 IEEE Power Engineering Society Winter Meeting, vol.1, NewYork, NY, 2002, pp.305-308. B.Kroposki,T.Basso,R.DeBlasio, Microgrid Standards and Technologies, Power and Energy Society General Meeting Conversion and Delivery of Electrical Energy in the 21st Century, 2008, pp.1-4. P.Mazza, The Smart Energy Network: Electricitys Third Great Revolution, Jun. 2003. [online]. Available: http://www.microplanet.com/upload/pdf/SmartEnergy.pdf, 22p. J.A.Momoh, Smart Grid Design for Efficient and Flexible Power Networks Operation and Control, IEEE Power Energy Society Power Systems Conference and Exposition, Seattle, Washington, 2009, pp.1-8. A.Mehrizini-Sani,R.Iravani, Secondary Control for Microgrids Using Potential Functions: Modeling Issues, Conference on Power Systems (CIGRECanada2009), Toronto, Canada, 2009, pp.1-9. A.Mohamed, Microgrid modeling and online management, PhD thesis, Helsinki University of Technology, Helsinki, Finland, 2008, 169p. D.Yubing,G.Yulei,L.Qingmin,W.Hui, Modelling and Simulation of the Microsources Within a Microgrid, Electrical Machines and Systems (ICEMS 2008), Jinan, China, 2008, pp.2667-2671. C.M.Colson,M.H.Nehrir, A Review of Challenges to Real-Time Power Management of Microgrids, IEEE Power Energy Society General Meeting, Calgary, Canada, 2009, pp.1-8. C.M.Colson,M.H.Nehrir,C.Wang, Ant Colony Optimization for Microgrid Multi-Objective Power Management, IEEE Power Energy Society Power Systems Conference and Exposition, Seattle, Washington, 2009, pp.1-7. S.Ahn,S.Moon, Economic Scheduling of Distributed Generators in a Microgrid Considering Various Constraints, IEEE Power Energy Society General Meeting, Calgary, Canada, 2009, pp.1-6. C.A.Hernandez-Aramburo,T.C.Green,N.Mugniot, Fuel Consumption Minimization of a Microgrid, Industry Applications, IEEE Transactions, 2005, vol.41, no.3, pp.673-681. A.Arulampalam,M.Barnes,A.Engler,A.Goodwin,N.Jenkins, Control of power electronic interfaces in distributed generation Microgrids, International Journal of Electronics, vol.91, no.9, London, GB, 2004, pp.503-524. F.Pilo,G.Pisano,G.G.Soma, Neural Implementation of MicroGrid Central Controllers, IEEE International Conference on Industrial Informatics, New York, 2007, pp.1177-1182. R.H.Lasseter,P.Piagi, Control and Design of Microgrid Components, Final Project Report Power Systems Engineering Research Center (PSERC-06-03), 2006, p. 257. P.Piagi,R.H.Lasseter, Autonomous Control of Microgrids, IEEE Power Engineering Society General Meeting, Montreal, Canada, 2006, pp.1-8. F.Z.Peng,Y.W.Li,L.M.Tolbert, Control and Protection of Power Electronics Interfaced Distributed Generation Systems in a Customer-Driven Microgrid, IEEE Power Energy Society General Meeting (PESGM 2009), Calgary, Canada, 2009, pp.1-8. R.H.Lasseter,P.Piagi, Microgrid: A Conceptual Solution, IEEE 35th Power Electronics Specialists Conference (PESC2004), vol.6, Aachen, Germany, 2004, pp.4285-4290. Y.Che,Z.Yang,K.W.EricCheng, Construction, Operation and Control of a Laboratory-Scale Microgrid, 3rd International Conference Power Electronics Systems and Applications, (PESA2009), 2009, pp.1-5. R.Lasseter,A.Akhil,C.Marnay,J.Stephens,J.Dagle,R.Guttromson,A.S.Meliopoulous,R.Yinger,J.Eto, The CERTS MicroGrid Concept, CEC Consultant Report P500-03-089F. Sacramento, CA: California Energy Commission, 2003, 32p. M.Adamiak,S.Bose,Y.Liu,J.Bahei-Eldin,J.DeBedout, Tieline Controls in Microgrid Applications, Bulk Power System Dynamics and Control VII. Revitalizing Operational Reliability, 2007 REP Symposium, 2007, pp.1-9. H.Gaztanaga,I.Etxeberria-Otadui,S.Bacha,D.Roye, Real-Time Analysis of the Control Structure and Management Functions of a Hybrid Microgrid System, IEEE 32nd Annual Conference Industrial Electronics, (IECON2006), 2006, pp.5137-5142. A.Rà ¶Ãƒ ¶p(editor,reviser), Annual Report 2008 Department of Electrical Drives and Power Electronics, Tallinn: TUT Publishing, Estonia, 2009, 74p. http://www.ab.com/PEMS/pm3000.html http://www.rockwellautomation.com/rockwellsoftware/assetmgmt/energymetrix/sysreq.html http://www.ab.com/programmablecontrol/pac/controllogix/ Design and Implementation of a Control System for a Microgrid involving a Fuel Cell Power Module A. P. Agalgaonkar, S. V. Kulkarni, S. A. Khaparde, and S. A. Soman, Placement and Penetration of Distributed Generation under Standard Market Design, International Journal of Emerging Electric Power Systems, Volume 1, Issue 1 2004; Article 1004 TOWARDS A SMART NETWORK IN A BUSINESS DISTRICT. COMBINING DISPERSED UPS WITH DISTRIBUTED GENERATION Designing the Optimal Stand alone Power System which uses Wind Power and Solar Radiation for Remote Area Object Placement and Penetration of Distributed Generation under Standard Market Design Off-Grid Diesel Power Plant Efficiency Optimization and Integration of Renewable Energy Sources Model. Validation and Coordinated Operation of a Photovoltaic Array and a Diesel Power Plant for Distributed Generation Distributed monitoring and control of future power systems via g

How Sustainable Is Industrial Agriculture Environmental Sciences Essay

How Sustainable Is Industrial Agriculture Environmental Sciences Essay Agriculture may seem to be a pre-modern economic activity in which the method or the way it is carried out is old-fashioned. However, industrialization, scientific development and mechanization have affected agriculture like many aspect of life, which created a brand new term: Industrial Agriculture. Industrialized agriculture or industrial agriculture can be defined as the replacement of human labor with capital intensive tools and inputs heavily dependent on fossil fuels, the consolidation of farm land, and increasingly centralized control over the distribution of food resources.(Thu and Dunenberger 1998). The goal of industrial agriculture is to increase yield and decrease costs of production, which is why the farm is seen as a factory with inputs like pesticides or fertilizer and outputs like corn or chicken. (Horrigan, Lawrence, Walker 1). Thanks to the industrial agriculture, the mass-production in agriculture came into existence. Compared to the old method, we can produce much more now. Agricultural food, including animals, can be supplied in a short time with more outcomes. Therefore, there is no doubt that in many ways industrial agriculture appears to be a beneficial development and a higher stage in agricultural method. However, it seems to be what it has brought is not as great as what it is taking away. The mechanization of agriculture and the use of chemicals, fertilizers and pesticides have caused huge problems in environment, health and the economic condition of farmers. That is why, in this paper, I will argue that industrial agriculture is unsustainable because it leads to unhealthy conditions for both workers and consumers, has negative effects on environment and causes poverty. The first aspect that makes industrial agriculture unsustainable is the health problems due to the conditions in work place, the use of pesticides, anti-biotic and fertilizers and the equipment used in the industrial agriculture. Workers are the first group of people who are exposed to the unhealthy conditions caused by the industrial agriculture. First of all, because of the equipment like farm machinery, tractors, hoes and etc., the accidents are frequent events for workers. The consequence of these kinds of accidents may be losing a hand, foot, small injuries or death. In 1946, data from all industrial groups show that the largest number of occupational deaths, 4,500, occurred in agriculture ( Axelrod 2). This data only belongs to USA so the number that includes more countries will increase the number of death also. Thus, accidents are a serious problem in industrial agriculture. Moreover, because of the high noise exposure from sources like tractors, harvesters and grain dryers, causes hearing loss among workers. According to Marvel farmers experience higher than expected rates of hearing loss starting in their teen years (Kendall 2) In addition to the accidents and noise exposure, the use of chemicals and pesticides in agriculture also creates unhealthy conditions for workers. Poisoning caused by chemical fertilizers seems to be faced by workers frequently. Pesticides used as plant sprays create a hazard to the farm worker either in the process spraying or of harvesting ( Axelrod 2). Thus, the chemicals and pesticides are serious treat to the health of farm workers and the most common illnesses because of these is poisoning. Furthermore, as Kendall points out, the dermatoses, especially skin cancer, and respiratory diseases are among the most pervasive health problems in industrial agriculture (1). Toxic exposure is the main reason for dermatoses. More specifically, exposure to pesticides, chemical solvents, engine exhaust, animal virsues and other substances commonly found in an industrialized farm operation are the reasons for dermatoses and especially skin cancer (Kendall 1). Other common health problem among farm workers is respiratory diseases. The condition in the work place and the material used for the works are again the reason for these kinds of problems. Exposure to irritant, toxic gases and dusts on the farm causes respiratory diseases. The kind of illnesses as a result from this includes chronic bronchitis, occupational asthma, organic dust toxic syndrome, farmers lung and silo filler (Kendall 2). Thus, respiratory diseases can seriously damage farm workers. In short, because of the condition of the work place, the equipment used in the work and the use of pesticides and chemicals, industrial agriculture creates an unhealthy condition that causes serious health problems for workers. In addition to the farm workers, consumers also suffer from unhealthy production and condition created by industrial agriculture. The use of chemicals and pesticides are causing some health problems for consumers as it is for workers. Statistical data provides us with information that makes it rather clear that the use of pesticides leads to serious health problems including fatal diseases. One of this data demonstrates that about 67,000 pesticide poisonings resulting in an estimated twenty-seven accidental fatalities are reported each year in the US in developing countries situation is worse (Pimental, Culliney, Bashore 2). Thus, again, the poisonings are frequent diseases resulted from the use of pesticides. More serious health problems like cancer can also occur because of pesticides. The International Agency for Research on Cancer found sufficient evidence of carcinogenicity in eighteen pesticides and limited evidence in additional sixteen pesticides (Pimental, Culliney, Bashore 2). In other words, there are eighteen pesticides which we are sure that can make people cancer. Since in industrial agriculture pesticides are being used excessively, the food that is produced by industrial agriculture is a serious treat for consumers. Other than the use of pesticides, so called factory style animal agriculture also creates health problems for consumers. The term factory style animal production implies the animal production in which unnatural method like using chemicals is being held. Pathogens like salmonella, laisteria and toxoplasma cause foodborn illnesses. These kinds of bacteria occur in chickens but they transmit to humans through meat. They can cause severe diarrhea and nausea and occasionally produce fatal diseases.(Horrigan, Lawrence, Walker 5). One may ask that if these bacteria transmit trough meat, why is the industrial agriculture guilty for these health problems? Horrigan, Lawrence and Walker give the answer: The crowded condition of factory farming increase the level of contamination and the high-speed, automated methods of slaughtering and processing the animals make it difficult to detect that contamination.(6) Furthermore, the other common characteristic of factory style animal agriculture that c auses health problems for consumers is the se of antibiotics. Unnatural or produced antibiotics are fed to animals. The goal is to promote growth in production. However, excessive use of such drugs in animals can enhance the development of drug resistant strain of disease, which can be transmitted to humans trough the food supply.(Horrigan, Lawrence, Walker 8). In other words, the excessive use of these antibiotics may make people less resistant to disease and make them ill more easily. The last aspect that industrial agriculture causes health problems is genetically engineered food. It is easy to guess this kind food creates heath problems because they are not natural. This kind of food à ¢Ã¢â€š ¬Ã‚ ¦includes organisms not previously eaten by humans.(Horrrigan, Lawrence, Walker 8), which may cause new allergens. Therefore, as there are organisms that we have not eaten before in genetically engineered food, it is likely that new allergens can emerge. The second reason why industrial agriculture is unsustainable is its negative effects on environment. Concerning environmental problems caused by industrial agriculture, the use of fertilizers and pesticides again seems to be the most important problem like it is about heath problems. It is a fair question to ask: why the use of fertilizers and pesticides is so intense, if it causes so many problems? It seems to be the answer is hidden in the definition of industrial agriculture given in the first paragraph. The industrial agriculture is a farm like a factory and it is goal is to produce more to profit more. The negative effects are not as important as the profit. Therefore, as the main goal is to earn money, health or environment are second or even third concerns. We can now continue to examine the negative effects on environment after this brief explanation. The use of chemical fertilizers and pesticides is serious problem for the environment and their rate of use is continuing to increase. The main problem about fertilizers arises from the fact that crops absorb one-third to one-half of the nitrogen.(Horrigan, Lawrence, Walker 3). Excess nitrogen creates dead zone because it diminishes the oxygen in the water. This drives off the mobile sea life and kills immobile bottom dwellers. One great example of this is Gulfs dead zone in New Jersey ( Horrigan, Lawrence, Walker 3). This nitrogen runoff also affects the ecosystem balance in a negative way, which is direct danger for environment. The use of pesticides is another problem because it causes decline in bird and beneficial insect populations which disrupt the balance between predator and prey.(Horrigan, Lawrence, Walker 3). As a result of this the pests are recovering faster, which can damage the agriculture directly. The reduction of biodiversity is another outcome. Syntheric chemicals reduce biodiversity in the insect world. This may not sound as a harmful result. However, the real problem is the death of the wild bees and other beneficial species by pesticides (Horrigan, Lawrence, Walker 3). The creation of imbalance in nature harms the biodiversity and kills the species that are beneficial to human kind. The effects of the industrial agriculture on soil demonstrate how harmful it can be on environment. Land degradation seems to be the first negative result of industrial agriculture. à ¢Ã¢â€š ¬Ã‚ ¦since World War II, poor farming practices had damaged about 550 million hectares-an area equivalent to 38% of all farmland in use today.(Horrigan, Lawrence, Walker 4). Because of industrial agriculture, more that one-third of the farmland had damaged. Considering world hunger, industrial agriculture had damaged all people by damaging that much of the land because the land could have been used efficiently, which could have supplied people with food or even land. The reason for why that much of land had damaged is that industrial agriculture à ¢Ã¢â€š ¬Ã‚ ¦depends on heavy machinery that compacts the soil, destroying soil structure and killing beneficial organisms in the soil food web.(Horrigan, Lawrence, Walker 4). Therefore, regarding soil, industrial agriculture is not sustainable. In terms of land, industrial agriculture is not very beneficial either. Land degradation has been a serious problem for a long time. The worlds supply of arable land per person has been declining steadily. (Horrigan, Lawrence, Walker 4). Desertification is a rather effective kind of land degradation. It can be defined as land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors including climatic variations and human activities. and 15% of al land surface has been experiencing land desertification. (Horrigan, Lawrence, Walker 4). This means that less land is available for agriculture. How can a type of agriculture be sustainable, if it reduces the land to use for agriculture? Less land means less family that are engaging in agriculture and less food to supply people with. The reasons for land degradation and desertification are over cultivation, overgrazing and over use of water.(Horrigan, Lawrence, Walker 4). Thus, the main reason is over using land and water but if the land degradation continues, in the end there will be no land to over use. The use of water is another aspect where the negative effects of industrial agriculture can be observed. The pollution of water seems to be the sources of problems that industrial agriculture causes because when farming practices pollute surface water and aquifers, they reduce the amount of water that is suitable for other uses.( Horrigan, Lawrence, Walker 4). Other users may be any plant, animals or person. The main point is that some practices of industrial agriculture pollute water and this waste water damages many other potential users. The pollution in most of the times stems from runoff of chemicals, silt and animal waste. (Horrigan, Lawrence, Walker 4). Again industrial agriculture seems to be for the benefit of only a few people, while it is harmful for many other people, animals or plants. Together with the problems concerning health and environment, the poverty caused by industrial agriculture is the last aspect that makes it unsustainable. One fact may be the starting point of poverty caused by industrial agriculture, which in seventy years, although the US population has doubled, the number of American farmers has declined from seven million to two million (Kimbrell 17). There may be two reasons for this. First one is land degradation, which is mentioned above, caused by industrial agriculture. Because of land degradation, the amount of arable land is diminishing, which leads to the loss of farm communities. As the farmers who were engaged in agriculture before finds no land, the poverty seems inevitable. The second reason may be higher costs of industrial agriculture. As industrial agriculture requires mechanization, the use of pesticides and chemicals, it is hard for farmers to continue in agriculture. Capital is needed for industrial agriculture, which many farme rs do not have. Therefore, the farms concentrate on very few people that have the capital to invest, which again causes the lass of farm communities and naturally poverty. The other reason for poverty caused by industrial agriculture is the increasing price of food. Although industrial agriculture made it possible to produce more, the price of food is increasing (Kimbrell 15). However, paradoxically farmers do not earn more than they did before. The profits gained from the increasing price of food go to the corporate middlemen, not to the farmers (Kimbrell 17). Other than farmers, society as a whole is becoming poor because of industrial agriculture as well. While food pricing is increasing, we spend money to the heath and environmental problems caused by industrial agriculture. Therefore, we pay more for the food and also we spend more money on health and environment because of industrial agriculture, which makes poverty a problem for the whole society. Poverty for farmers and for the whole society again demonstrates that industrial agriculture is not sustainable. In conclusion, even though industrial agriculture is a development in agriculture as it increases production, it takes more than it gives so it is unsustainable. Negative effects of it on heath, environment and economy are the reasons for why industrial agriculture is unsustainable. Creation of health problems both for workers and consumers because of the use of pesticides, chemical and the conditions of work place causing toxic exposure and accidents is thanks to industrial agriculture. The use of pesticides, chemicals, land degradation and water pollution are the environmental problems created by industrial agriculture. The loss of farm communities and expensive food price are the results of industrial agriculture, which causes poverty. All these reasons seem to demonstrate that industrial agriculture is unsustainable. The solution to these problems may not be going back to the old fashion way of agriculture in which there is no room for mechanization, pesticides or chemicals. All this chemicals or machines should be used for human good, not to gain more profit. Therefore, the problem is not the kind of things that is used in agriculture; the real problem is the relations of production or the social form in which these kinds of things are used. Therefore, in order to achieve sustainable agriculture, we should first abolish the possibility of making profit by industrial agriculture. Then, we should collectivize the means of production and just use them for the human good. WORK CITED Axelrod, S. J. Health Problems in Industrialized Agriculture School of Public Health. September 1949: 1172-1175. Print. Horrigan, Leo, Lawrence Robert S. ,Walker, Polly. How Sustainable Can Agriculture Address the Environmental and Human Health Harms of Industrial Agriculture. Environmental Health Perspective, Vol.110 No.5 May 2002. 445-456. Print Kendall, M. Thu. The Health Consequences of Industrial Agriculture for Farmers in the United States. Human Organization. Fall 1998. Print Kimbrell, Andrew. Fatal Harvest: The Tragedy of Industrial Agriculture. Washington, DC: Island Press, 2002. Print Pimentel, D., T.W. Culliney, T. Bashore. http://ipmworld.umn.edu/chapters/pimentel.htm

Ambition By Moonlight - Original Writing :: Papers

Ambition By Moonlight - Original Writing The wind howled through Francis' mass of tatty black hair, that looked like a bird's nest, making it stream out behind him. He found it hard to keep his balance walking against the wind; it was like it was trying to lift him up and wisp him off, back to his warm welcoming house where he should be at this very moment. The long, thick grass was covered in frost; it looked like someone had sprinkled a thin layer of salt crystals across the field. It crunched under his feet, making Francis cringe, as he cautiously moved onwards, head bowed against the wind. He could feel the cold, deep down in his bones, despite wearing his thick trousers and fur coat. Suddenly he saw the last bit of the light from the village disappear in some shadows, Francis stopped abruptly and looked up slowly. First of all he noticed the old wooden signpost with its writing barely legible, craning his neck further he saw the mass of bare branches from the towering trees of the wood. The branches looked like frail hands and seemed to be trying to snatch him to haul him into the woods Francis was frozen in his step, transfixed by the woods in front of him, even though he could only see the very edge of the woods it still frightened him and made him jump at the slightest sound. Then all of a sudden the moon appeared bright in the sky from behind the clouds that appeared to have been swept aside by a large hand. It hung in the sky like bricks, lighting the field like a vast beacon. It was then Francis could have sworn he saw a small figure like that of a child, watching him, and appearing strangely familiar but he couldn't put his finger on whom it could be. Yet as quickly as he had seen it, it vanished, Francis shook his head telling himself he was just seeing things. Francis started to edge towards the woods, but just before he entered

Severe Burns: Neutrophil and Complement Levels Essay -- Medicine

Mortality rate in burn patients continues at a steady 5-10%, 75% of those deaths are related to sepsis (2). In order to understand why, we must elucidate the nature of the innate immune system in these patients. The innate immune system is the first line defense versus pathogens from the outside world. Burn patients receive a double hit to their first line defenses due to the nature of thermal injury to tissue. The skin barrier is breached, the inflammation begins, and though the numbers of neutrophils increases substantially in response to the elevations in compliment activation at the tissue level (1), it seems that the behavior of these neutrophils is aberrant (2). Neutrophils in burn patients were found to be impaired in their ability to adhere, phagocytose, and kill off pathogens via the oxidative burst. Additionally, they were found to have decreased migration speed with abnormal directionality in response to chemoattractants (2). One study suggested that neutrophils in burn pa tients became desensitized to C5a. In the rich inflammatory cytokine milieu, which develops after a severe burn, complement levels increase dramatically, but neutrophils downregulate their C5a receptors and their migratory directional speed decreases (3). This is the perfect situation for the wandering pathogen to invade and sneak past the body’s defenses in the chaos of a massive breach in security. Three studies are presented here to describe the relationship between complement and neutrophils in the severely burned patient. Van de Goot et al. demonstrated that plasma complement levels initially decreased, then rose sharply and stayed elevated for months afterward. Complement levels correlated with the severity of the burn wound and subsequent sc... ...enter around how to control the inflammatory response to the thermal injury such that wound healing occurs more quickly with less scarring, while preserving the patients’ ability to fight infectious agents with normal neutrophil responses. Works Cited 1. Van de Goot et al. Acute Inflammation is Persistent Locally in Burn Wounds: A Pivotal Role for Complement and C-Reactive Protein. Journal of Burn Care and Research 2009; 30:274-280. 2. Butler KL, Ambravaneswaran V, Agrawal N, Bilodeau M, Toner M, et al. (2010) Burn Injury Reduces Neutrophil Directional Migration Speed in Microfluidic Devices. PLoS ONE 5(7): e11921. doi:10.1371/journal.pone.0011921 3. Solomkin JS, Nelson RD, Chenoweth DE, Solem LD, Simmons RL. Regulation of Neutrophil Migratory Function in Burn Injury by Complement Activation Products. Annals of Surgery 1984; Vol 200 No. 6: 742-746.

Angiosperms and Gymnosperms

PRACTICAL 6 Seed Plants (Gymnosperms and Angiosperms) OBJECTIVES: 1. To describe the features of seed plant life cycle and the concept of the dominant generation. 2. To describe the life histories and related reproductive structures of gymnosperms and angiosperms. 3. To summarize the features that distinguish gymnosperms and angiosperms. 4. To discuss the advantages of seed plants to dominate land and their evolutionary adaptations on land. EXPERIMENT 1: Gymnosperms INTRODUCTION:Gymnosperms (720 species in 65 genera) are ancient seed plants that include ginkgos (Division Ginkgophyta), cycads (Division Cycadophyta), conifers (Division Coniferophyta), and gnetophytes (Division Gnetophyta). The term gymnosperm derives from the Greek wood roots gymnos, meaning â€Å"naked†, and sperma, meaning â€Å"seed†. They are naked-seeded plants meaning that the ovule, which becomes a seed, is exposed on the sporophyte at pollination. Mature seed are not enclosed in a fruit as are tho se of flowering plants. Gymnosperms are best known for their characteristic cones, called strobili.These strobili display sporangia and their subsequently developing ovules and pollens. Gymnosperms do not require water for sperm to swim to reach the egg as do seedless plants. Instead, immense amount of windblown pollen are produced. Most gymnosperm cones, including the familiar pine cone, are complex whorls of leaflike, woody scales around a central axis. The smallest cones include those of the junipers (Juniperus) which have flesh scales fused into a structure resembling a berry. The larger cones may weigh 45 kg and are produced by cycads.In most gymnosperm species, the female megastrobilus is larger and distinctive from the male microstrobilus. MATERIALS: 1. Living or preserved specimens of * Ginkgo (Ginkgo biloba) * Cycad (Cycad sp. ) * Pine (Pinus sp. ) 2. Prepared slide of gymnosperms 3. Compound microscope 4. Dissecting microscope 5. Slide and coverslip 6. Forceps 7. Distilled water PROCEDURE: A ginkgo: 1. A prepared slide of male strobilus of Ginkgo biloba is examined. The microsporophyll, microsporangium, and strobilus axis are identified. 2. A prepared slide of female strobilus of Ginkgo biloba is examined.The megasporophyll, megasporangium, and strobilus axis are identified. A cycad: 1. A female cycad is examined. The leaves, megasporophylls, megasporangia and developing seed are identified. 2. The pollen cone bears on male cycad. Pollinated cone is examined and microsporophyll, microsporangia, and pollen grains are identified. A pine: 1. A male cone and female cone of Pinus sp. are obtained. 2. A prepared slide of longitudinal section of female cone is examined. The megasporophyll, megasporangia, and ovule are looked. 3. A prepared slide of longitudinal section of male cone is examined.The microsporophyll, microsporangia, and pollen grains are looked. 4. Fertilization occurs after the pollen tube penetrates the megasporangium and allows sperm to ent er the archegonium and fuses with the egg. The zygote will form after fertilization. A prepared slide of the developing embryo of Pinus sp. is examined. 5. Mature seed cone is obtained. The seed with wing attached to the ovuliferous scale is found. 6. The anatomy of pine leaf one needle is examined. The following: epidermis, stoma, photosynthetic mesophyll, endodermis, phloem, xylem, and resin duct are identified.RESULTS Cross section of Ginkgo Biloba Cross section of Cycad Cross section of female pine Cross section of male pine EXPERIMENT 2: Angiosperms INTRODUCTION: Angiosperms are the most abundant, diverse, and widespread of all land plants. They are successful because they are structurally diverse, have efficient vascular systems, share a variety of mutualisms (especially with insects and fungi), and have short generation times. Flowering plants are important to human because our world economy is overwhelmingly based on them.Indeed, we eat and use vegetative structures (roots, stems and leaves) as well as reproductive structure (flowers, seeds, and fruits). You will find that many of the vegetative structures are quite similar to those of more ancient plants shown. The roots, stems, and leaves of flowering plants function just as those of ferns and cone bearing plants. Flowers and fruits, however are unique adaptations of angiosperms. Biologists believe that the extraordinary adaptiveness of these structures has led to the proliferation of the incredible diversity found among flowering plants. MATERIALS: 1.Living specimens of angiosperms (dicots & monocots) with roots, stems, leaves, flowers, fruits and seeds. (Imperata cylindrical, zea mays, Carica papaya, Phaseolus sp. ) 2. Prepared slide of angiosperms (dicots & monocots) 3. Compound microscope 4. Dissecting microscope 5. Slide and coverslip 6. Forceps 7. Distilled water PROCEDURE: Roots: 1. A root of dicots and monocots are obtained for morphology and anatomy study. 2. The root systems of representati ve dicot and monocot are looked. 3. Cross section of dicot root shows the central stele is surrounded by a thick cortex and epidermis.The following: epidermis, cortex, parenchyma cells, starch grains, pericycle, endodermis, phloem, and xylem are identified. 4. Cross section of monocot roor shows this root has a vascular cylinder of xylem and phloem that surrounds a central pith. The following: epidermis, cortex, endodermis, Casparian strip, pith, phloem, and xylem are identified. 5. A prepared slide of the roots for some other species is obtained and their structure is identified. Stems: 1. The longitudinal section of shoot tip of representative dicot and monocot is studied.The following: leaf, leaf primordium, apical meristem, ground meristem, axillary bud, vascular bundle, and pith are identified. 2. A dicot and monocot is obtained and a cross section of the stems is made and the arrangement of vascular bundles is examined. The anatomy between this dicot and monocot is compared. 3 . For both type of plants, epidermis, cortex, phloem, xylem, cambium, pith, and vascular bundle are identified. Leaves: 1. Fresh specimen provided in lab is looked. Flowering plants show a variety of morphology to identify, such as, leaf arrangements and leaf venation. 2.Using fresh prepared slide or prepared slide of some flowering plants, the structure of the leaves is studied. The leaves have common features: cuticle, air space, lower epidermis, upper epidermis, palisade mesophyll, spongy mesophyll, and vascular bundle are noticed. Flowers: 1. The longitudinal section of some flowers is looked. The parts of a flower: stigma, pistil, style, ovary, sepal, receptacle, peduncle, petal, filament, stamen, and anther are named. 2. A prepared slide of a cross section of mature anther (lily anther) is examined. Sections of the four microsporangia are found.Pollen grains within a microsporangium is looked. 3. A prepared slide of a cross section of an ovary (lily ovary). The several ovules are found. Megaspore mother cell within megasporangium is looked. The megasporangium develops is studied. The placenta, integuments, microphyle, egg cell, central cell, and polar nuclei are identified. 4. The demonstration slide of double fertilization is observed and the zygote, primary endosperm nucleus, and central cell of the female gametophyte are identified. Fruits and seeds 1. A sample of dry, dehiscent fruits (peanuts) is obtained.The fruit wall, cotyledon, plumule of embryo, embryo, radical, cotyledon, and seed coat are identified. 2. A sample of simple flesy fruits (tomato, a berry) is obtained. Pericarp, mesocarp, endocarp, locule, seed and placenta are identified. 3. A prepared slide of corn grain (Zea mays), a caryopsis fruit is examined. The pericarp of a corn grains is tightly united and inseparable from the seed. The pricarp, endosperm, cotyledon, coleoptiles, plumule bud, embryo, radical, and coleorhizae are identified. RESULTS Cross section of root Cross section of stemCross section of leaves Cross section of flower Cross section of seed DISCUSSION For the lower vascular plants the important evolutionary development was in the water and food conducting tissues of the sporophyte. As we move on through the plant kingdom the next important development was the seed. The free living gametophyte is a vulnerable phase of the life cycle. Reproduction by seeds is a less chancy procedure and has other advantages for plant survival and dispersal. Seeds can be remarkably tolerant of environmental extremes heat, cold and drought.Unlike free-living gametophytes seeds can postpone their development until conditions are right. And, of course, we find them very convenient for plant propagation. Already in the coal-measure forests there were plants that reproduced by seeds. Some were the so-called â€Å"seed ferns†. Others were the ancestors of the plants we now know collectively as â€Å"gymnosperms†. In these plants the seeds are not enclosed i n an ovary, as in the flowering plants; they grow on the surface of a modified leaf in a strobilus or cone. â€Å"Gymnosperm† means naked seed. Alternation of generations is still involved in the reproduction of these plants.They are all heterosporous: the microspores are shed as pollen, whereas the megaspore germinates in the strobilus to produce the female gametophyte. The archegonia in this gametophyte get fertilized by sperm from the male gametophyte and the zygote grows to produce an embryo which is enclosed in a seed coat of tissue from the parent plant. Gymnosperms were the dominant land plants in the age of dinosaurs, the Cretaceous and  Jurassic periods. The surviving gymnosperms in the Coniferophyta, Cycadophyta and Ginkgophyta are similar in their woody habit and pattern of seed development but are not closely related.The characteristic feature of angiosperms is the flower. Flowers show remarkable variation in form and elaboration, and provide the most trustworth y external characteristics for establishing relationships among angiosperm species. The function of the flower is to ensure fertilization of the ovule and development of  fruit  containing  seeds. The floral apparatus may arise terminally on a shoot or from the axil of a leaf (where the  petiole  attaches to the stem). Occasionally, as in  violets, a flower arises singly in the axil of an ordinary foliage-leaf.More typically, the flower-bearing portion of the plant is sharply distinguished from the foliage-bearing or vegetative portion, and forms a more or less elaborate branch-system called an  inflorescence. There are two kinds of reproductive cells produced by flowers. Microspores, which will divide to become  pollen grains, are the â€Å"male† cells and are borne in the  stamens  (or microsporophylls). The â€Å"female† cells called megaspores, which will divide to become the egg cell (megagametogenesis), are contained in the  ovule  and enc losed in thecarpel  (or megasporophyll).The flower may consist only of these parts, as in  willow, where each flower comprises only a few stamens or two carpels. Usually, other structures are present and serve to protect the sporophylls and to form an envelope attractive to pollinators. The individual members of these surrounding structures are known as  sepals  and  petals  (or  tepalsin flowers such as  Magnolia  where sepals and petals are not distinguishable from each other). The outer series (calyx of sepals) is usually green and leaf-like, and functions to protect the rest of the flower, especially the bud.The inner series (corolla of petals) is, in general, white or brightly colored, and is more delicate in structure. It functions to attract  insect  or  bird  pollinators. Attraction is effected by color,  scent, and  nectar, which may be secreted in some part of the flower. The characteristics that attract pollinators account for the popularity of flowers and flowering plants among humans. While the majority of flowers are perfect or  hermaphrodite  (having both pollen and ovule producing parts in the same flower structure), flowering plants have developed numerous morphological and  physiological  mechanisms to reduce or prevent self-fertilization.Heteromorphic flowers have short carpels and long stamens, or vice versa, so animal  pollinators  cannot easily transfer pollen to the pistil (receptive part of the carpel). Homomorphic flowers may employ a biochemical (physiological) mechanism calledself-incompatibility  to discriminate between self- and non-self pollen grains. In other species, the male and female parts are morphologically separated, developing on different flowers. POST-LAB QUESTIONS: 1. How to distinguish between a male and female cone of pine?The male cone will form at the bottom of the tree and it is much smaller than the female and the male produces the pollen grains and the female produces the ovule and forms at the top of the tree. 2. Explain the characteristics of gymnosperm seeds to aid in dispersal. Many gymnosperms have winged seeds that aid in dispersal. Generally, gymnosperms have heavy seeds so the wings only assist in moving the seed a short distance from the parent plant. 3. List some uses for conifers. Economically, conifers are very important as they are a major source of timber.The majority of the world’s sawn timbers come from conifers. Exploitation of this resource from wild growing forests is still going on in many parts of the world, but there is an obvious trend especially in the developed world to phase this out and use more sustainable planted or seeded resources. There are many species with highly different wood properties, some of these are extremely valuable and used for fine cabinet making or expensive applications in construction. Wood from conifers is also an important source of pulp for paper and cellulose fibres such as rayon.Conifer s also very important in horticulture, especially in regions with a temperate climate. Several species have yielded hundreds of different cultivars and new ones are constantly appearing on the market. In some countries conifers have a role to play in traditional medicine and in religious ceremonies and, of course, our Christmas trees can be seen as a form of this kind of use. A few conifers even have edible seeds; well known are those of certain pines. 4. Lists the common characteristics of seeds plants. i. They have vascular tissue ii.They use seeds to reproduce iii. They all have body plans that include leaves, stems, and roots. 5. Contrast between dicots and monocots, the two classes of flowering plants. Monocots| Dicots| Herbaceous| May be woody or herbaceous| Embryo with single cotyledon| Embryo with 2 cotyledons| Flower parts in multiple of three| Flower parts with multiple of 4 or 5| Parallel-veined leaves| Net-veined leaves| Bundles of vascular tissue are scattred throughout the stem| Vascular bundle in the stem forms rings| Roots are adventitious| Root develop from radicle| . Discuss the features of plant flowering fruits and seeds. Seeds  develop from ovules in the ovary, and at maturity consist of an  embryo  and a reserve food supply surrounded by a protective covering, the  seed coat. The diversity of flowering plants assures diversity among their seeds, but, unlike fruits, which have numerous variations, structural plans for seeds are few. The reserve food can be stored either in or out of the embryo and the  cotyledons, the seed leaves can remain either below ground or be elevated above the surface when germination occurs.Fruits are ripened ovaries containing seeds with sometimes additional flower or inflorescence tissues associated with them. Only angiosperms produce flowers and fruits. From a botanical viewpoint, many of the foods we eat as vegetables are fruits, for examples, tomatoes, green beans, squash, eggplant, and peppers. Fru its apparently arose as a means not only of protecting the seeds, but as a way to ensure their dispersal. REFERENCES 1. http://faculty. unlv. edu/landau/gymnosperms. htm 2. http://www. kew. org/plants/conifers/uses. html 3. http://edhelper. com/ReadingComprehension_37_251. html