Thursday, April 17, 2014

Persuasive Essay on Biodiversity

Biodiversity is the diversity of live organisms in all its forms. Biodiversity is quite a broad term which can be understood in the different way. First of all it is the genetic diversity, because every organism has its own unique code of genes and their variations which are inherited from generation to generation. Then there is the diversity of species, which is characterized with the variety of the types of the living organisms which can be differentiated according to the inner and outer features, lifestyle, the way of feeding, breeding, etc. And finally, there is the diversity on the level of ecosystems, or the differences between various ecosystems, their structures, elements and functioning. The major concepts of biodiversity were proclaimed in the first part of the 20th century, which depended on the level of the development of biology and its methodology of the research. 

Biodiversity is one of the most important factors which maintains life on the planet, because only the great variety of species is able to support the existence and appropriate life of ecosystems. If a single element of the ecosystem disappears, the whole ecosystem will be ruined. Unfortunately, the humanity did not think about this issue till the middle of the 20th century, and the human activity was the major factor of the extinction of numerous biological species and destruction of ecosystems. Nowadays there is a task to maintain biodiversity of Earth and protect species from extinction in order to save ecosystems and as a result save more and more species which can be endangered by the disappearance of the single specie of animals.

Biodiversity is the essential factor of the appropriate existence of live organisms on the planet and the student is supposed to be aware about this matter. The aim of the persuasive essay is to convince the reader in the importance of the maintenance of the biodiversity on the definite examples from the real life. The young professional is able to discuss the issue in detail, dwell on the strong and weak sides of the problem, write about the factors which cause harm to biodiversity and share the possible solutions to the problem. Furthermore, one can focus on the effect of the damaged biodiversity on the life of Earth.

There are several problems related with the preparation of the well-analyzed persuasive essay and the main one is the lack of the student’s experience. One can find the answers to the bothering questions in a free example persuasive essay on biodiversity found in the web. The student is able to learn about the correct approach towards writing and formatting reading a free sample persuasive essay on biodiversity written online. 

If you need a high-quality custom persuasive essay on Biodiversity topic - you can order it online.

Thursday, April 10, 2014

Essay on Half Wave Single Phase Converters

In Single-phase half wave converters, either the negative or positive half AC wave is blocked or the remaining half is allowed to pass. The means that only one-half of the input reaches in the output, which indicates that, the resulting voltage is lower. A half wave converter requires just single diode in case of single-phase supply and in case of three-phase supply, it needs three diodes. Converters or rectifiers yield pulsating and unidirectional direct current. However, half wave single-phase converter produces far more ripple compared to the full wave rectifier. In addition, increased filtering is required for eliminating the harmonics associated with AC frequency of the output.


  • A single phase half wave uncontrolled circuit converter is a simple and low cost circuit. Although the power levels of such circuit are very small, yet it is widely used and simplest rectifier.
  • The current flow through the circuit and its output voltage are highly influenced by the type of load.


  • The output current carried by load also contains some component of ac current in addition to dc current. The frequency of such ac component is almost equal to the input voltage frequency. In order to controlled high ripple factor, a complicated filtering is needed in order to produce steady dc output.
  • Only half amount of power is delivered at one time, which result in low rectification and power output.
  • The transformer utilization factor is also very low.
  • Current is magnetized by the DC saturation associated with the transformer core. It also results in harmonies generation and loss of hysteresis.
  • The power supply of single phase half wave uncontrolled circuit converter is not suitable for general power supply. Such type of power supply is best suitable only for some sort of charging.
  • The simplest single phase half wave uncontrolled circuit converter is not suitable for industrial use mainly due to poor performance.
  • It requires large filter capacitor in order to obtain smooth dc output voltage.


  • Single-phase half wave controlled circuit converter is widely used in the industrial applications of different types.
  • They have the ability to use both negative and positive voltage and can supply current, which is unidirectional. 
  • They have the capacity to operate in the form of an inverter or a controlled rectifier.
  • Single-phase half wave controlled circuit has an inverter mode, which blocks the forward voltage of the thyristors, which result in the negative direction of output voltage.


  • The single-phase half wave controlled circuit has poor voltage and current from both input and power factors.
  • These circuits have lower efficiency and low dc output.
  • The ripple current and ripple voltage of such converters are high.
  • The ripple factor of single-phase half wave controlled circuit is relatively higher.
  • These converters have low utilization of transformer factor.
  • As the dc component is supplied with the input current, it results in the dc saturation in the output transformer core.
  • Single-phase half wave controlled circuit is rarely used in the practical life due to their extremely low output and dc output power.
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