bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unsaturated polyester resin via chemical recycling of off‐grade poly(ethylene terephthalate)
Authors: Zahedi Ali Reza , Rafizadeh Mehdi , Ghafarian Seyed Reza 
Published: July 2009

AbstractBACKGROUND: The chemical recycling of poly(ethylene terephthalate) (PET), e.g. bottles and fibre wastes, has been studied for many years. Among several methods proposed for chemical recycling of waste PET, glycolysis makes it possible to employ very low amounts of reactants and lower temperatures and pressures compared with critical methanol and thermal degradation. Furthermore, unlike hydrolysis under acidic or basic conditions, glycolysis does not cause any problems related to corrosion and pollution.RESULTS: PET from off‐grades of industrial manufacture was depolymerized using excess glycol. The effects of the reaction time, volume of glycol and catalyst concentrations on the yield of the glycolysis products were investigated. A reaction time of 3 h, weight ratio (catalyst to PET) of 0.25 wt% and PET to ethylene glycol molar ratio of 1:5 were determined as suitable conditions for depolymerization. Then, the reaction of polyesterification of maleic anhydride (MA) and glycolysed products of PET was successfully performed at 160 and 190 °C for 8 h.CONCLUSION: Differential scanning calorimetry and vapour pressure osmometry results for the product of the glycolysis reactions, under suitable condition, confirmed the structure of the desired product. This sample underwent reaction with MA to produce unsaturated polyester resin (UPR). The results of Fourier transform infrared and NMR spectroscopy confirmed that the UPR had been synthesized successfully. This is the first direct report on the glycolysis reaction of off‐grade products of petrochemical companies in order to regenerate raw materials or other secondary value‐added products. Copyright © 2009 Society of Chemical Industry
Burning Characteristics of Ammonium Nitrate‐based Composite Propellants Supplemented with Ammonium Dichromate
Authors: Kohga Makoto , Nishino Saeko 
Published: July 2009

AbstractAmmonium nitrate (AN)‐based composite propellants have attracted much attention, primarily because of the clean burning nature of AN as an oxidizer. However, such propellants have some disadvantages such as poor ignition and low burning rate. Ammonium dichromate (ADC) is used as a burning catalyst for AN‐based propellants; however, the effect of ADC on the burning characteristics has yet to be sufficiently delineated. The burning characteristics of AN/ADC propellants prepared with various contents of AN and ADC have been investigated in this study. The theoretical performance of an AN‐based propellant is improved by the addition of ADC. The increase in the burning rate is enhanced and the pressure deflagration limit (PDL) becomes lower with increasing amount of ADC added. The increasing ratio of the burning rate with respect to the amount of ADC is independent of the AN content and the combustion pressure. The optimal amount of ADC for improving the burning characteristics has been determined.
Gastrointestinal system
Authors: Cheng Leo K. , O'Grady Gregory , Du Peng , Egbuji John U. , Windsor John A. , Pullan Andrew J. 
Published: July 2009

AbstractThe functions of the gastrointestinal (GI) tract include digestion, absorption, excretion, and protection. In this review, we focus on the electrical activity of the stomach and small intestine, which underlies the motility of these organs, and where the most detailed systems descriptions and computational models have been based to date. Much of this discussion is also applicable to the rest of the GI tract. This review covers four major spatial scales: cell, tissue, organ, and torso, and discusses the methods of investigation and the challenges associated with each. We begin by describing the origin of the electrical activity in the interstitial cells of Cajal, and its spread to smooth muscle cells. The spread of electrical activity through the stomach and small intestine is then described, followed by the resultant electrical and magnetic activity that may be recorded on the body surface. A number of common and highly symptomatic GI conditions involve abnormal electrical and/or motor activity, which are often termed functional disorders. In the last section of this review we address approaches being used to characterize and diagnose abnormalities in the electrical activity and how these might be applied in the clinical setting. The understanding of electrophysiology and motility of the GI system remains a challenging field, and the review discusses how biophysically based mathematical models can help to bridge gaps in our current knowledge, through integration of otherwise separate concepts. Copyright © 2009 John Wiley & Sons, Inc.This article is categorized under:

Physiology > Mammalian Physiology in Health and Disease
Biophysics and dynamics of natural and engineered stem cell microenvironments
Authors: Keung Albert J. , Healy Kevin E. , Kumar Sanjay , Schaffer David V. 
Published: July 2009

AbstractStem cells are defined by their ability to self‐renew and to differentiate into one or more mature lineages, and they reside within natural niches in many types of adult and embryonic tissues that present them with complex signals to regulate these two hallmark properties. The diverse nature of these in vivo microenvironments raises important questions about the microenvironmental cues regulating stem cell plasticity, and the stem cell field has built a strong foundation of knowledge on the biochemical identities and regulatory effects of the soluble, cellular, and extracellular matrix factors surrounding stem cells through the isolation and culture of stem cells in vitro within microenvironments that, in effect, emulate the properties of the natural niche. Recent work, however, has expanded the field's perspective to include biophysical and dynamic characteristics of the microenvironment. These include biomechanical characteristics such as elastic modulus, shear force, and cyclic strain; architectural properties such as geometry, topography, and dimensionality; and dynamic structures and ligand profiles. We will review how these microenvironmental characteristics have been shown to regulate stem cell fate and discuss future research directions that may help expand our current understanding of stem cell biology and aid its application to regenerative medicine. Copyright © 2009 John Wiley & Sons, Inc.This article is categorized under:

Developmental Biology > Stem Cell Biology and Regeneration
ON FIXED POINTS OF GENERALIZED SET-VALUED CONTRACTIONS
Authors: BENAHMED S. , AZÉ D. 
Published: July 2009

AbstractUsing a variational method introduced in [D. Azé and J.-N. Corvellec, ‘A variational method in fixed point results with inwardness conditions’, Proc. Amer. Math. Soc.134(12) (2006), 3577–3583], deriving directly from the Ekeland principle, we give a general result on the existence of a fixed point for a very general class of multifunctions, generalizing the recent results of [Y. Feng and S. Liu, ‘Fixed point theorems for multi-valued contractive mappings and multi-valued Caristi type mappings’, J. Math. Anal. Appl.317(1) (2006), 103–112; D. Klim and D. Wardowski, ‘Fixed point theorems for set-valued contractions in complete metric spaces’, J. Math. Anal. Appl.334(1) (2007), 132–139]. Moreover, we give a sharp estimate for the distance to the fixed-points set.
Some Principles of the Law of Trusts in West Africa
Authors: Daniels W. C. Ekow 
Published: July 2009

“Of all the exploits of equity, the largest and the most important is the invention and development of the trust.”These were the words of Maitland.2 In the course of his lecture, the learned professor ascribed the invention of the Law of trusts to the work of English lawyers. Before going any further, it should be pointed out that the institution of trusts is one which is not peculiar to English law.
Integration of Judicial Systems: The Recent Reform of the Local Courts Appeal System of Tanganyika
Authors: Lewis-Barned J. F. de S. 
Published: July 2009

The year 1962 saw an important step towards further integration of the judicial system of Tanganyika.Before describing what has taken place in recent months, it would perhaps be appropriate to sketch briefly the historical background of the Local Courts appeal system.The German administration, whilst tacitly recognizing the existence of a system of customary law and procedure, in fact administered justice at District level through an officer similar to the British District Commissioner, who heard cases himself, though he was sometimes required to recognize a specific customary law. Sometimes he delegated his authority on his own initiative and in an ad hoc manner, either to leading persons such as the pre-existing Liwalis and Kadhis, or to Akidas who had been appointed by the Germans themselves. However, the actual responsibility for the administration of justice was not generally delegated nor were native courts defined or established until the advent of British administration.
Loans in Kenya on the Security of Chattels: II
Authors: Oulton A. D. M. 
Published: July 2009

The economic aspects of the hire-purchase movement are well known and it is not intended to discuss them here. It will be sufficient to point out that hire-purchase finance enables people, in certain circumstances, to live by taking in, not each other's washing, but their own. This remarkable achievement was recently explained byThe Times:“The reliance on funds from the public to finance consumer hire-purchase spending is, in fact, a paradox in that the public is ultimately financing itself. As it is pointed out in the second edition ofHire Purchase in a Free Society, the man who subscribes to a life endowment policy yet chooses to buy a car on hire-purchase rather than liquidate it may in effect be financing himself.”
Customary Law and the Economy
Authors: Snyder Francis 
Published: July 2009

In this paper I discuss some aspects of the relationship of African customary law to the economy. Such a vast topic potentially embraces at least three different themes: the economic context in which African customary law has developed and operates today; the economic consequences and implications of different African customary laws; and the relationship between customary law and the economic aspect of society. These three themes inevitably overlap, but while recognising their interconnections I shall concentrate primarily on the third. My principal aim is to identify some of the linkages between customary law and economic relations, especially those linkages which become manifest during broad social changes.An examination of the relationship between customary law and the economy in Africa almost ineluctably requires an historical perspective. This is so, first, because, as I suggest later, customary law is historically specific: it developed in particular historical circumstances and in close conjunction with the formation of the colonial state. Thus, the foundations of customary law in Africa lie partly in the development of capitalism and its expansion from Europe during the colonial era. These interrelated processes have decisively moulded and subtly shaped the law, legal institutions and legal professions of contemporary Africa.More generally, however, it is essential today to envisage the possibility of new, alternative forms of development and social regulation. The particular forms of legal pluralism which characterise third world countries indicate, in many cases, that the subsumption of African economies within capitalist relations of production and exchange has thus far been merely partial and formal.
What is to be done with African Customary Law?
Authors: Allott A. N. 
Published: July 2009

What I should like to do today is to examine the evolution of customary law in English-speaking Africa over the last three decades. I have chosen my starting date of 1950 with a clear intention in view; because the developments that we observe currently taking place often find their origins in the colonial period. They do this in two ways. First, the laws which the African countries inherited at independence had been crucially shaped by the colonial experience; and secondly, some of the projects of law reform which have either taken place or are now under discussion trace back to initiatives and discussions which occurred during the latter part of colonial rule. There is a further factor: quite apart from conscious efforts to analyse and change the laws, the laws themselves, of whatever kind, have been exposed to the forces of economic, political and social change, which are continually working away below the surface, sapping the foundations of the existing legal systems.My own qualifications for this task I do not feel that I should dwell on. However, it is worth remarking, as symptomatic of the profound upheavals which have occurred within the period, that I was appointed to the first post in Britain of lecturer in African law in 1948. This was the period of the immediate post-war reconstruction of the British colonial empire in Africa. Things were not the same as they had been up to the Allied victory in 1945.
Techniques of Choice of Law in Conflict of Personal Laws
Authors: Tier Akolda M. 
Published: July 2009

The division of state inhabitants into communities living under different laws opens up possibilities of conflicts problems on an unprecedented scale. These problems may arise not only when members of different communities enter into legal relationships, but also when the parties, whether members of the same community or not, choose to regulate their legal relations in accordance with another personal law. The occurrence of either of these circumstances poses some problems for which the law is difficult or uncertain. This study attempts to examine with particular reference to the Sudan the problem of choice of law to be administered.In examining the problem of choice of law I shall attempt to show and compare how different systems of personal laws (i.e., where personal laws are administered in their respective courts of nationality, religion or ethnic community and courts which administer two or more personal laws) try to solve choice of law problems. It is apparent that the existence of thelex foriin the former and its absence in the latter should affect the approach to the problem of choice of law. The contrast between the two approaches is striking. The contention here is that systems of personal laws always apply theirlex foriand treat questions of choice of law as mere questions of competence.
Legislative History of the Legal Regime of Price Control in Ghana
Authors: Ansa-Asare K. 
Published: July 2009

The most common consumer complaint in Ghana now is that prices of consumer goods are too dear. It is common knowledge that prices of basic goods change almost every month. Life in Ghana shows that price control has been one of the difficult problems that successive governments have faced since the termination of colonial rule.The primary intention of this article is to present a descriptive account of price control legislation in Ghana, in the hope that it will interest as well as be informative to the reader.
Changing African Perspectives on the Right of Self-Determination in the Wake of the Banjul Charter on Human and Peoples′ Rights
Authors: Blay S. Kwaw Nyameke 
Published: July 2009

In the history of modern Africa the issue of self-determination has always been of special significance. For a better part of a century and in some cases more, almost the entire continent was subject to colonisation by various European powers. The end of the Second World War and the subsequent adoption of the United Nations Charter, incorporating the principle of self-determination, heralded a new phase for the African colonies in international relations. Defined in its simplest terms, self-determination is the principle by virtue of which a people freely determine their political status and freely pursue their economic, social and cultural development. Selfdetermination is in essence the right of self-government. A territory exercises the right by either opting to establish itself as an independent state, associating with an existing state or by accepting to be integrated into an existing state. Self-determination so defined was thus used as the basis for decolonisation in Africa and provided the foundations for equal statehood for the former colonies of Africa in international relations.After decolonisation, the issue of self-determination still persists in Africa attracting sentiments and implications well exemplified by the conflicts Over Biafra and Katanga in the 1960s and currently in Eritrea, the Tigray province of Ethiopia and the Southern Sudan. The very successful propagation of self-determination as the right of every people to self-government by African nationalists during the colonial days seems to have left behind a legacy of a question for post-independence Africa—is the ideal of self-determination
Constitutionalism in Zambia: Past, Present and Future
Authors: Ndulo Muna B. , Kent Robert B. 
Published: July 2009

Writing about any constitution is tricky business and that of Zambia is no exception. Four constitutions in 32 years hardly represents a settled state of affairs, and an end, or even a stopping place of long duration, does not appear in sight. This is, however, an interesting, even exciting period in Zambia’s brief constitutional history. The subject cries out for an examination of where the country has been, where it is, and where, at least in the opinion of these observers, it ought to be heading.We are happy to undertake this brief assessment in the context of recognition of the career of Professor J.S. Read. This able, patient, effective, and thoughtful scholar has been a mentor to generations of African lawyers, including Zambians. To both of us Jim Read has been a warm and generous friend, from time to time a wise counsellor who has contributed much to our own efforts.
A Review of Rent Control Legislation in Botswana
Authors: Frimpong Kwame 
Published: July 2009

The subject “Rent Control” is very wide as it covers many areas. It may deal with the control of rents in respect of agricultural land, industrial property or it may be limited either to dwelling houses or commercial buildings. For the purposes of this paper, “rent control” focuses on the dwelling or residential houses and commercial buildings in the country. The obvious reason is that the current rent control legislation is limited to those properties because of the apparent high level of the rents they attract.The use of legislation to control rents of premises is a product of the twentieth century. In England, for instance, the first attempt to control rents was in 1915, during the First World War. It is interesting to note that the first legislation on rent control in England coincided with the outbreak of the First World War. Rent controls in Nigeria and Ghana were also influenced by the First and Second World Wars respectively. The reason for the introduction of rent control legislation to coincide with world wars is not hard to find. Wars generally create shortages of a number of essential goods because many resources are diverted to the production of armaments and the labour force is channelled to the battle front. Housing is one of the needs of mankind which usually becomes scarce as a result of the outbreak of a major war like the last two World Wars.
The Beleaguered Fortress: Reflections of the Independence of Nigeria's Judiciary
Authors: Olowofoyeku A. A. 
Published: July 2009

Informed opinions on the judiciary in Nigeria vary between the rather equivocal comment by a senior member of the bar that “The judiciary is dead”, or the view that it is “on trial” and the more compassionate view that it is a “beast of burden” or a “sacrificial lamb”. These remarks derive from observations of the (alleged or actual) behaviour of the judges, and their independence, impartiality and integrity. While the metaphors quoted above may be subject to various interpretations, they do raise considerable curiosity and interest as to why any judiciary should attract such comments, and perhaps to what extent the comments are justified. This article, in attempting to answer these and similar nagging questions concerning Nigeria's judiciary, examines the truly multi-faceted question of judicial independence by assessing the Nigerian situation in the light of the factors that are considered vital to ensuring or guaranteeing an independent judiciary.Interestingly, although section 17(1)(e) of the Nigerian Constitution provides that “The independence, impartiality and integrity of Courts of Law, and easy accessibility thereto shall be secured and maintained”, this provision is under the chapter titled “Fundamental Objectives and Directive Principles of State Policy”, whose provisions are non-justiciable by virtue of section 6(6) (c) of the Constitution. Thus the high-sounding declaration of section 17(1)(e) has no bite, and what could have been a constitutional guarantee of judicial independence is no more than a slogan.
The Military and the Criminal Law in Nigeria
Authors: Owoade M. Adekunle 
Published: July 2009

Nigeria was under military rule from 1966 to 1979, and from December 1983 to date; it had a short civilian interregnum from 1979 to 1983 during the era of President Shehu Shagari.This rather long period of military administration in Nigeria brought along with it changes in the scope of substantive criminal law as well as procedural changes. This can be partly explained on the ground that the criminal law must react and adjust to societal changes and formulate its own rules to combat them. However, an assessment of the attitude of the military to criminal law might suggest that certain fundamental rules have been sacrificed for despatch.This article is an attempt to highlight the contribution of the military administrations to the development and scope of criminal law in Nigeria. The approach is to examine the various important criminal law enactments of the military era with a view to see their impact, if any, on the hitherto existing rules and system of criminal law.
Re-Allocation of Matrimonial Property at the Dissolution of Marriage in Zimbabwe
Authors: Ncube Welshman 
Published: July 2009

Most countries of the world have at one time or another been confronted with questions of what principles or rules should guide the courts in readjusting the property rights of spouses at the dissolution of their marriage. Virtually all civilised countries have accepted marriage as an equal partnership of two legally equal individuals to which each one of them contributes in one way or another. Most policy makers agree that the partners contribute to the marriage through their division of labour and that these contributions although not equal in absolute terms are nonetheless of equal relative value to the welfare of the family.This recognition of the equal worth and equal importance of the two spouses to a marriage relationship has had profound effects on the matrimonial property regimes of numerous countries which have had to tackle the problem of the construction of a fair and equitable legal formula for the reallocation of matrimonial property rights at the dissolution of marriage. The fundamental problem has been whether a fair and equitable system is achieved by means of fixed rules of apportionment or through flexible discretionary judicial powers exercisable at the discretion of courts, in the light of the individual circumstances of each case.