The preparation of 3B-(2-mercaptoethylamino)-cholestane was set as the goal of this thesis project.

Online group-buying is more and more popular, and under the trend, more and more group-buying websites are established. We all know the every website has different strategy--some offer special service, some offer special discount, and some offer special goods. And which one is much better? On the other hand, what kind of customer will shop via the group-buying websites? If the online-buying experience affect the behavior? The purpose of the research is to analysis the different strategies among the online group-buying platform. Besides, the research also tries to find if the different using experiences from these platforms will differ the group-buying behavior. The research result indicates that the group-buying websites which offer price discounts and purchasing-related service are easy to get better performance. And the friendly operating instructions could lower the resistance for customers to join into the websites.

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This dissertation describes an algorithm and its implementation in the computer algebra system GAP for constructing the cohomology ring and Ext-algebra for certain group algebras kG. We compute in the Morita equivalent basic algebra B of kG and obtain the cohomology ring and Ext-algebra for the group algebra kG up to isomorphism. As this work is from a computational point of view, we consider the cohomology ring and Ext-algebra via projective resolutions.There are two main methods for computing projective resolutions. One method uses linear algebra and the other method uses noncommutative Grobner basis theory. Both methods are implemented in GAP and results in terms of timings are given. To use the noncommutative Grobner basis theory, we have implemented and designed an alternative algorithm to the Buchberger algorithm when given a finite dimensional algebra in terms of a basis consisting of monomials in the generators of the algebra and action of generators on the basis.The group algebras we are mainly concerned with here are for simple groups in characteristic dividing the order of the group. We have computed the Ext-algebra and cohomology ring for a variety of simple groups to a given degree and have thus added many more examples to the few that have thus far been computed.

Thesis (M.H.A.)--University of Michigan, 1963.

Thesis (M.H.A.)--University of Michigan, 1963.

Thesis (Ph. D.)--University of Hong Kong, 1993.

Thesis (D. Min.)--Trinity Evangelical Divinity School, 1994. / Abstract. Includes bibliographical references (leaves 222-226).

Chapter 1 is a short review of the main results in some areas of the theory of group rings. In the first half of Chapter 2 we determine the ideal theoretic structure of the group ring RG where G is the direct product of a finite Abelian group and an ordered group with R a completely primary ring. Our choice of rings and groups entails that the study centres mainly on zero divisor ideals of group rings and hence it contributes in a small way to the zero divisor problem. We show that if R is a completely primary ring, then there exists a one-one correspondence of the prime zero divisor ideals in RG and RG¯, G finite cyclic of order n. If R is a ring with the property α, β € R, then αβ = 0 implies βα = 0, and S is an ordered semigroup, we show that if ∑α¡s¡ ∈ RS is a divisor of zero, then the coefficients α¡ belong to a zero divisor ideal in R. The converse is proved in the case where R is a commutative Noetherian ring. These results are applied to give an account of the zero divisors in the group ring over the direct product of a finite Abelian group and an ordered group with coefficients in a completely primary ring. In the second half of Chapter 2 we determine the units of the group ring RG where R is not necessarily commutative and G is an ordered group. If R is a ring such that if α, β € R and αβ = 0, then βα = 0, and if G is an ordered group, then we show that ∑αg(subscript)g is a unit in RG if and only if there exists ∑βh(subscript)h in RG such that∑αg(subscript)βg(subscript)-1 = 1 and αg(subscriptβh is nilpotent whenever GH≠1. We also show that if R is a ring with no nilpotent elements ≠0 and no idempotents ≠0,1, then RG has only trivial units. In this chapter we also consider strongly prime rings. We prove that RG is strongly prime if R is strongly prime and G is an unique product (u.p.) group. If H ⊲ G such that G/H is right ordered, then it is shown that RG is strongly prime if RH is strongly prime. In Chapter 3 results are derived to indicate the relations between certain classes of ideals in R and RG. If δ is a property of ideals defined for ideals in R and RG, then the "going up" condition holds for δ-ideals if Q being a δ-ideal in R implies that QG is a δ-ideal in RG. The "going down" condition is satisfied if P being a δ-ideal in RG implies that P∩ R is a δ-ideal in R. We proved that the "going up" and "going down" conditions are satisfied for prime ideals, ℓ-prime ideals, q-semiprime ideals and strongly prime ideals. These results are then applied to obtain certain relations between different radicals of the ring R and the group ring (semigroup ring) RG (RS). Similarly, results about the relation between the ideals and the radicals of the group rings RH and RG, where H is a central subgroup of G, are obtained. For the upper nil radical we prove that ⋃(RG) (RH) ⊆ RG, H a central subgroup of G, if G/H is an ordered group . If S is an ordered semigroup, however, then ⋃(RS) ⊆ ⋃(R)S for any ring R. In Chapter 4 we determine relations between various radicals in certain classes of group rings. In Section 4.3, as an extension of a result of Tan, we prove that P(R)G = P(RG) , R a ring with identity , if and only if the order of no finite normal subgroup of G is a zero divisor in R/P(R). If R is any ring with identity and H a normal subgroup of G such that G/H is an ordered group, we show that ⊓(RH)·RG = ⋃(RG) = ⊓(RG) , if ⋃(RH) is nilpotent. Similar results are obtained for the semigroup ring RS, S ordered. It is also shown if R is commutative and G finite of order n, then J(R)G = J(RG) if and only if n is not a zero divisor in R/J(R), J(R) being the Jacobson radical of R. For the Brown HcCoy radical we determine the following: If R is Brown McCoy semisimple or if R is a simple ring with identity, then B(RG) = (0), where G is a finitely generated torsion free Abelian group. In the last section we determine further relations between some of the previously defined radicals, in particular between P(R), U(R) and J(R). Among other results, the following relations between the abovementioned radicals are obtained: U(RS) = U(R)S = P(RS) = J(RS) where R is a left Goldie ring and S an ordered semigroup with unity

A previous thesis by Kerr and Kirkham (I963) indicated the extent to which caseworkers worked with groups in Vancouver. The present study continues this investigation, focussing on how caseworkers use themselves as change agents in such groups. An interview schedule was used to obtain from the workers the necessary data. This information was then classified according to the purpose and goals of the group, and the role of the worker, using the conceptual framework of Dr. J. Klein as model. The study revealed that each of the groups could be placed in one or the other of Klein's three categories: group education, social group treatment, or group psychotherapy. It was found that lack of clarity of purpose resulted in conflicting goals, with a consequent confusion in worker role. Most frequently, inexperience on the part of the agency or worker was the cause for confusion of purpose. It was seen that a written statement of purpose contributed to a clear perception of goal and role. The need for caseworkers to set conscious goals for each meeting was established. Particular attention was given the goals established in the first and final meetings: planned goals were common for the first meeting, inconsistency of appropriate goals common in the final meeting. Analysis of the difficulties on the part of most workers in their role in the group, suggest the following as possible causes: (1) lack of clarity of purpose; (2) lack of clarity of goals; (3) lack of knowledge of group process; (4) lack of necessary skills; and (5) confusion in professional identity. It is important that workers in the psychotherapy groups should have a clear perception of purpose and understanding of appropriate role. Some findings in relation to "open-ended groups" appear which agencies should take into consideration when planning such a group. Knowledge and training in social group work is obviously valuable for caseworkers if they are to work with groups; and the need is clear for further study to be undertaken of caseworkers working with groups. / Arts, Faculty of / Social Work, School of / Graduate