Modeling And Simulation Of The Switched Reluctance Motor

This Paper summarizes the study conducted on the techniques used and implemented to minimize the torque ripple of the Switched reluctance Motors. These motors although offering the advantages of higher speeds, reliability and phase independence, have the limitations of the torque ripple and non-linearity in the magnetic characteristics. Thus in order to have the good understanding of the Motor, it is simulated in the MATLAB/SIMULINK environment. This paper describes details on modeling of two different configurations of Switched Reluctance Motor concentrating only on the linear model by obeying all of its characteristics. The two configurations of motors are applied with two different control techniques and the results are calculated and tabulated. Load and No load analysis are also performed to understand the behavior of motor with load. Through out the analysis, various values of turn-on and turn-off angles are selected and finally the optimum values are calculated based on the performance parameters of Average torque, speed and torque ripple. All simulations are documented through this paper including its block models and initializations performed. Finally a control technique is recommended which produces the best results with smallest torque ripple

Ergonomic Immobilization Frame for Radiotherapy

The primary purpose of this project is to demonstrate that patients can be safely immobilized using air in the general torso area so that radiation can be administered to that region. The primary target will be to treat tumors in the lungs and liver. By immobilizing patients during treatment it allows for the radiation to be consistent in targeting the desired region of the body, which would not be the case if the patient was moving. Air was chosen as the desired medium to immobilize the patient because of comfort and it provides an easy medium for radiation to travel through which does not interfere with the radiation. Through research the limiting factor of human body was the pulmonary cycle which was determined to be approximately 0.15 Psi. In order to use air for immobilization airbags were incorporated as a means to hold the air and once pressurized would be used as the restraint force on the patient. As a means to demonstrate that air in fact could be used to immobilize a patient a prototype of a radiation chamber was built to provide a proof of concept. The radiation chamber frame was built to completely encapsulate the patient 360 degrees. The two airbags were placed in the frame which provides complete immobilization of the patient from all angles. The patient had to be standing while the radiation was being administered in order to target certain areas which could not be included if the patient was sitting or lying down. A circular frame was the desired shape of the frame because it allows for radiation to enter and exit the chamber at the same angle regardless of where it is administered. The radiation chamber requires the use of radiation safe materials in any given area where the frame comes into contact with radiation, for this reason non-metallic materials were used. The chamber prototype was built using wood and plexiglass. Finite element analysis simulated an allowable applied pressure of 6.0 Psi applied to the shell. Prior to the given prototype, there was no means available to immobilize a patient while standing for radiotherapy. Experimental tests demonstrated that a person could be immobilized in the general torso area using air.https://scholarscompass.vcu.edu/capstone/1214/thumbnail.jp

Modeling And Simulation Of The Switched Reluctance Motor

This Paper summarizes the study conducted on the techniques used and implemented to minimize the torque ripple of the Switched reluctance Motors. These motors although offering the advantages of higher speeds, reliability and phase independence, have the limitations of the torque ripple and non-linearity in the magnetic characteristics. Thus in order to have the good understanding of the Motor, it is simulated in the MATLAB/SIMULINK environment. This paper describes details on modeling of two different configurations of Switched Reluctance Motor concentrating only on the linear model by obeying all of its characteristics. The two configurations of motors are applied with two different control techniques and the results are calculated and tabulated. Load and No load analysis are also performed to understand the behavior of motor with load. Through out the analysis, various values of turn-on and turn-off angles are selected and finally the optimum values are calculated based on the performance parameters of Average torque, speed and torque ripple. All simulations are documented through this paper including its block models and initializations performed. Finally a control technique is recommended which produces the best results with smallest torque ripple

Contributory intend as a defence limiting or excluding delictual liability

“Contributory intent” refers to the situation where, besides the defendant being at fault and causing harm to the plaintiff, the plaintiff also intentionally causes harm to him- or herself. “Contributory intent” can have the effect of either excluding the defendant’s liability (on the ground that the plaintiff's voluntary assumption of risk or intent completely cancels the defendant's negligence and therefore liability), or limiting the defendant’s liability (where both parties intentionally cause the plaintiff's loss thereby resulting in the reduction of the defendant’s liability). Under our law the "contributory intent" of the plaintiff, can either serve as a complete defence in terms of common law or it can serve to limit the defendant's liability in terms of the Apportionment of Damages Act 34 of 1956. The “Apportionment of Loss Bill 2003” which has been prepared to replace the current Act provides for the applicability of “contributory intent” as a defence limiting liability, but it is yet to be promulgated.Criminal and Procedural LawLL. M

The explicit and implicit influence of reasonableness on the elements of delictual liability

Reasonableness as a concept used in determining delictual liability or liability in tort law, is either embraced or perceived by some as frustrating. It is a normative concept which is inextricably linked with the concepts of fairness, justice, equity, public policy and the values of the community. These concepts assist in providing value judgements in determining liability. It is apparent from this study that the influence of reasonableness is predominantly implicit on the French law of delict, but more explicit on the South African law of delict and Anglo-American tort law. Its influence varies with respect to each element of tort or delictual liability. In order to hold a person liable for a delict or tort, it is only reasonable that all the elements of a delict or tort are present. Common to all the jurisdictions studied in this thesis is the idea of striking a balance between the defendant’s interests promoted, the plaintiff’s interests adversely affected and the interests of society. Where liability is based on fault, the reasonableness of conduct is called into question. In respect of causation whichever test or theory is used, what must ultimately be determined is whether according to the facts of the case, it is reasonable to impute liability on the defendant for the factually caused consequences. Whether loss or harm is required, assumed or not required, the question of the appropriate remedy or compensation which is reasonable under the circumstances is called into question. In South African and Anglo-American law, the multiple uses of the standards of the reasonable person, reasonable foreseeability of harm, reasonable preventability of harm, whether it is reasonable to impose an element of liability, or whether it is reasonable to impute liability, often cause confusion and uncertainty. At times, the role of these criteria with regard to a specific element may be valid and amplified while, at other times, their role is diminished and controversial. However, there is nothing wrong with the concept of reasonableness itself; indeed, it is a necessary and useful concept in law. Rather, it is the way that it is interpreted and applied in determining liability that is problematic.Private LawLL. D

"Contributory Intent" as a Defence Limiting Delictual Liability

In terms of delictual liability, the term "fault" generally refers to the defendant's conduct, whereas "contributory fault" refers to the plaintiff's conduct. "Contributory intent" is a form of "contributory fault" and may apply as a defence limiting delictual liability within the ambit of the Apportionment of Damages Act 34 of 1956 (hereinafter referred to as the "Act"). In terms of the Act, the extent of the plaintiff's as against the defendant's fault is taken into account, resulting (in certain instances) in a reduction of the award to the plaintiff. The Act currently regulates the apportionment of damages based on fault in South Africa. The Act does not specifically provide for conduct performed intentionally, and this also seems to be the situation in quite a few foreign jurisdictions. Initially our courts applied the Act to instances of "contributory negligence" (the other form of "contributory fault") only, but in recent times they have applied it to instances of "contributory intent". This change has occurred as a result of practical situations that arose unexpectedly, where the courts had in the interest of serving justice to deal with cases of intentional conduct on the part of the plaintiff and the defendant. The effect of "contributory intent" as a defence in terms of delictual liability is uncertain and contentious not only in South Africa but in foreign jurisdictions as well. The South African Law Reform Commission undertook a review of the Act and published a report on its findings. The Commission acknowledged that since the Act was passed there have been major developments in the law of delict which the Act has been unable to accommodate, resulting in anomalies in this area of the law. It acknowledged that it is unsatisfactory for our courts to go beyond the parameters of the Act in order to reach a just and equitable result when dealing with the apportionment of liability. The Apportionment of Loss Bill 2003 (hereinafter referred as the "Bill") has been drafted to replace the current Act but has unfortunately not been promulgated. Over ten years have passed since it was drafted. In respect of the Bill, "contributory intent" as a defence limiting delictual liability would be recognised. It is hoped that this contribution will bring about a renewed interest in this forgotten but valuable Bill.  &nbsp

The influence of 'reasonableness' on the element of conduct in delictual or tort liability ─ comparative conclusions

In this contribution the influence of reasonableness on the element of conduct in the South African law of delict will be analysed and compared with the requirement of some form of conduct in English tort law, American tort law and the French law of delict. Fundamental similarities and differences among the different legal systems must be considered. France and South Africa follow a generalising approach to determining a delict while English and American law have a system of separate torts. Even though English and American law do not explicitly refer to the requirement of conduct in tort law, it is generally implicitly required. This is the case whether one is dealing with the tort of negligence or the intentional torts. In French law too, a fait générateur (a generating, triggering, wrongful act or event) generally must also be present in order to ground delictual liability. The concept of fait générateur is broader than the concept of conduct found in the other jurisdictions in that it extends beyond what is regarded as human conduct. The conduct in all the jurisdictions may be in the form of a commission (a positive, physical act or statement) or an omission (a failure to act). The requirement that conduct must be voluntary is generally found in South African, English and American law (with an exception applying to mentally impaired persons) but not in France. Naturally, it is unreasonable to hold a person liable without conduct which results in the causing of harm or loss. In all the above-mentioned jurisdictions, it would generally be unreasonable to hold the wrongdoer liable in delict or tort law if the omission or commission does not qualify as some form of conduct. Thus the influence of reasonableness on the element of conduct in all the above-mentioned jurisdictions is implicit.Private La

The origins of the recent new approach to determining wrongfulness in the South African law of delict

Much has been written about the “new” or “variation” of the test for wrongfulness in determining delictual liability in South African law. Upon researching English tort law, it has become apparent that the origin of this “new” test or “new variation” of the test (referred to as the “recent approach”) is in all probability from English tort law and more specifically from the test applied in determining a “duty of care” with regard to the tort of negligence. The South African courts, in applying this recent approach, are in fact drawing closer to adopting English law and the tort of negligence. In this note, the recent approach as well as the test applied to determining wrongfulness before this recent approach (referred to as the “traditional approach”) will be mentioned briefly. Fundamental similarities and differences between the South African law of delict and English tort law will be referred to briefly. The English test for determining a duty of care will be discussed and compared with the recent approach to determining wrongfulness in South African law. A conclusion will follow with a summary of the submissions made.Private La