bluuebunny/crossref_metadata_2025 huggingface dataset:
A tale of two regimes: imperialism, the military and class in Ghana
Authors: Hutchful Eboe
Published: July 2007

Written before the 1979 coup led by Jeny Rawlings and the recent return to civilian rule, this article provides essential background to those events. It outlines the crisis that was looming and that eventually created the setting for this latest military intervention. This is set against the background of an analysis of the two earlier military regimes, of 1966 and 1972, which explores their social character and their economic policies. It is argued that such an analysis has to explore the complex relations and mediations between imperialism and the local petty bourgeoisie and between different fractions of the petty bourgeoisie. Beyond, these differences between the various regimes, however, there is a common stance of compromise rather than confrontation with imperialism, and a common fate: recurrent crises which stem from the differing attempts to mediate between foreign and local capital.
Notes on state and peasantry: the Tanzanian case
Authors: Bernstein Henry
Published: July 2007

This paper is complementary to the author's previous ‘Notes on Capital and Peasantry’ (Review10). In that article, the role of the state in promoting the commoditisation of peasant agriculture was alluded to, a theme which is pursued further here. This is done through a number of provisional hypotheses which ‘map out’ three connected areas of contradictions: contradictions in the circuits of peasant economy, in the apparatuses and practices of the state, and in the sphere of state‐peasant relations. These schematic hypotheses are presented with the intention of contributing to current debates about the nature of the agrarian question, and of the state, in contemporary Africa.
Women's groups and women's subordination: an analysis of policies towards rural women in Kenya
Authors: Feldman Rayah
Published: July 2007

Rural women in Kenya are burdened by heavy workloads, often being responsible not just for attending to domestic needs — including provision of food for their families — but having as well to work as casual labourers. They are further hampered by lack of access to income obtained from the sale of cash crops grown by the household, even though they often contribute labour to the cultivation of such crops. In these and other ways they suffer the impact of gender relations which place them firmly in a position of economic subordination. The Kenyan government has acknowledged that women are ‘disadvantaged’ and has made a formal commitment to alleviate their situation. Economic and political crises, however, have tended to displace attention from the needs of oppressed groups in Kenya, including women. But it would be questionable in any case that the prevailing perception of a solution based on ‘integrating women into development’ would bring about significant change. Rayah Feldman examines a set of organisations on which government policy towards women has been focused: women's groups coordinated by the Kenyan Women's Bureau. Her analysis suggests that while assisting some women to generate extra income, their impact is sparse, uneven and often of dubious value. Seldom indeed do their projects, even when successful in terms of profitability, approach the requirements for fundamentally altering the condition of subordination of rural women.
Hunger and weapons: the entropy of militarisation
Authors: Shindo Eiichi
Published: July 2007

The author argues against the view that hunger in the ‘Third World’ and nuclear militarism in the developed world are two separated phenomena. The increasing militarisation of the Third World is directly related to famine‐induced hunger suffered by its populations. Military expenditure ‘crowds out’ expenditure on agriculture, while the militarisation of the developed countries’ economies results, via the mechanisms of investment and trade, in the militarisation of Third World industrial production. This further distorts their economies and leads to the entropy of famine.
The politics of crisis in Ghana: class struggle and organisation, 1981–84
Authors: Graham Yao
Published: July 2007

In ROAPE32 we published a critique of the present regime in Ghana by Zaya Yeebo. We had intended to offer an alternative critique by Yao Graham as well, as a contribution to the ongoing debate about the direction being taken by the Rawlings government. Lack of space and the need for more writing time forced us to postpone Yao Graham's contribution until this issue, but we hope it will be read alongside Zaya Yeebo's piece. Below is a shortened version of Graham's article.
Reviews
Authors: Zack‐Williams A.B. , Warren Jenny , Arogundade Tunde , Haynes Jeffrey
Published: July 2007

The Sociology of Developmentby Aidan Foster‐Carter (Causeway Press, Ormskirk, Lancashire, UK, 1985) pp. 128 with bibliography.

Angola to the 1990s: The Potential for Recoveryby Tony Hodges, Special Report Economic Intelligence Unit NO. 1079, January 1987. £85 (25% academic discount)

Industrial Relations in Developing Countries: the Case of NigeriaBy A.K. Ubeku, (Macmillan Press, London, 1983)

Ghana: Politics, Economics and Societyby Donald I. Ray (Pinter, London, 1986)
The World Bank in rural Nigeria, revisited: a review of the World Bank's Nigeria: agricultural sector review 1987
Authors: Williams Gavin
Published: July 2007

The World Bank's policy recommendations have come under extensive and often critical scrutiny in Nigeria, as elsewhere, since the military government adopted the main tenets of the World Bank's Structural Adjustment Programme [SAP]. SAP has had a major impact on agriculture, notably as a result of the substantial devaluation of the naira through the creation of the Foreign Exchange Market [FEM] and the abolition of the Commodity Marketing Boards [CMBs]. These long overdue reforms have sharply raised prices for export crops in naira and improved the competitiveness of crops grown in Nigeria as against imports. Less attention has been paid to the World Bank's policies for agriculture, despite the extensive involvement of the Bank, through the projects it has funded.

The World Bank's 1987 Agricultural Sector Review [ASR] sustains the analysis and recommendations of previous reviews of agricultural policy in Nigeria, notably of the Consortium for the Study of Nigerian Rural Development [CSNRD], and of the Bank itself. ASR recommends the development of what it calls ‘tradeable’ crops, cocoa, rubber and oilseeds, as well as maize and cotton, by applying ‘improved’ technical packages and raising ‘management skills’. These were the intended foci of the crop rehabilitation projects and of the Agricultural Development Projects [ADPs] initiated and funded by the World Bank in the 1970s. It is apparent from the report and its annexes that these projects failed to realise the expected returns, but the report itself conceals the World Bank's own involvement.
Salim A. Salim on the Oau and the African agenda
Authors: Bing Adotey
Published: July 2007

On 11 October 1990, Salim Ahmed Salim, the Secretary General of the Organisation of African Unity, delivered the inaugural Africa Centre Lecture in London on ‘The OAU and the African Agenda in the 1990s’. The issues he raised are likely to occupy African minds throughout this decade and perhaps beyond. This article gives an account of them but also offers a commentary on their implications.
Responses to the Gulf crisis in the Maghreb
Authors: Seddon David
Published: July 2007

Governments in the Maghreb (northwest Africa) have generally opposed the military offensive against Iraq while condemning the invasion and calling for withdrawal. Even Morocco, which initially sent a small contingent of troops to Saudi Arabia, has moved closer to its neighbours in the Union of the Arab Maghreb which has been active in pressing for a negotiated settlement. Popular responses throughout the Maghreb have been strongly in support of Iraq and against the war; huge demonstrations have taken place in Algeria, Tunisia and Morocco. Fuelled by widespread and growing political frustration and by deteriorating conditions, popular resentment at Western (and particularly US) intervention in the region and in Arab affairs has grown dramatically since the war started in January and is likely to provide the basis for political instability in the Maghreb over the coming months and even years.
The democracy debate in Africa: Tanzania
Authors: Shivji Issa G.
Published: July 2007

The current debate on democracy in Africa (see ROAPE no.49) is stimulating but many views are rooted in liberalism, justify it in terms of ‘development’ or see it as an absolute good. Little attempt is made to situate it in the historical processes of people in struggle, resulting in a mistrust of the masses. Applying these strictures to the recently officially‐launched debate on the party system in Tanzania, it is argued that the very way the debate is itself conducted must also be democratic and should reflect the people's own strivings not the ‘negative’ models of the East, or the ‘positive’ models (and pressures) of the West. The limitations of the present ‘party‐state’ and its monopoly of politics are criticised. Proposals are made not for a specific constitutional formula but for an extended transition ‘process’ that should be followed, opening up debate in civil society and paving the way for a National Convention and a Constituent Assembly.
Adjustment for stabilisation or growth? Ghana and the Gambia
Authors: Parfitt Trevor W.
Published: July 2007

Ghana and The Gambia are part of the group of African states that have been following programmes of structural adjustment (SAPs) throughout most of the 1980s and into the 1990s. They are also amongst the states that the Bretton Woods institutions (BWIs) have periodically cited as success stories for adjustment. The aims of adjustment policies are well known to analysts of African political economy. Their theoretical foundations lie within a brand of neo‐classical economics that emphasises the advantages of nonintervention in the free market and, conversely, the risks attendant on state attempts to regulate or intervene in the market. It follows that this line of thought anathematises the attempts of various African states to promote indigenous industrial development. State spending on such aims is deemed inflationary and wasteful inasmuch as it is believed to promote inefficient industries that can only survive on the basis of state subsidisation and protection against foreign competition. State concentration on the industrial sector can also be seen as providing a disincentive to those sectors of the economy that are actually productive, notably the rural sector, since it is the producers in the latter sectors that have to foot the bill for state intervention.

Structural adjustment is designed to counteract these tendencies through a variety of policy measures, including imposition of limits on fiscal and public spending policies in order to limit inflationary and wasteful state expenditure; deregulation and privatisation which are also designed to reduce state spending; liberalisation of the tariff regime in order to ensure that the productive sectors are opened up to market competition and therefore have to use resources efficiently; and devaluation which is necessary to counteract the tendency towards overvaluation of the currency that results from the pursuit of inflationary policies. An examination of the economic policies of many African states (including Ghana and The Gambia) suggests they have fallen into these very traps. The BWIs have therefore insisted that such states must undergo structural adjustment so that they will utilise their resources more efficiently — in accordance with the free market, that is. Only through taking this course can the foundations for growth be laid argue the BWIs. The following case studies examine how the conditions for growth actually have been attained in Ghana and The Gambia, paying particular attention to the issue of how far adjustment policies are conducive to industrial growth.
Book notes
Authors: Love Roy , Bush Ray , Szeftel Morris
Published: July 2007

Collapsed States: the Disintegration and Restoration of Legitimate Authority
by William Zartman (ed) (1995), Lynne Reinner. ISBN 1-55587-518-1,1-55587-560-2.

The Reality of Aid 95
, Earthscan 1995, ISBN 1 85383 292 8.

Women in Micro- and Small-scale Enterprise Development
by L Dignard, L & J Havet (eds) (1995), Westview Press and IT Publications. ISBN 0-8133-8894-5.

Development Studies: A Reader
by S Corbridge (ed) (1995), Edward Arnold. ISBN 0 340 61452 8 (pb).

Land Law in Lesotho: the Politics of the 1979 Land Act
by A S Franklin (1995), Avebury. ISBN 1 85628 976 1.

Africa in World Politics: Post-Cold War Challenges
by J W Harbeson & D Rothchild (eds) (1995), Westview. ISBN 0-8133-2102-6, 0-8133-2103-4.

Democratisation and Demilitarisation in Lesotho: The General Election of 1993 and its Aftermath
by R Southall & T Petlane (eds) (1995), Africa Institute of South Africa, Pretoria. ISBN 0-7983-0123-6.

Deconstructing Apartheid Discourse
by Aletta J Norval (1996), Verso, ISBN 1-85984-125-2.

Ethnicity and Development in Nigeria
by Okwudiba Nnoli (1995), Research in Ethnic Relations Series, Avebury. ISBN 1 85972 115 X.

Power of Development
by Jonathan Crush (1995) (ed), Routledge. ISBN 0-415-11177-3.

Citizen and Subject: Contemporary Africa and the Legacy of Late Colonialism
by Mahmood Mamdani (1996), Uganda (Fountain), South Africa (David Philip), London (James Currey). ISBN 9970-02-090-0.
Guerre absurde entre l'ethiopie et l'erythrée
Authors: Péninou Jean‐Louis
Published: July 2007

The war that has broken out between Eritrea and Ethiopia has surprised everyone, as it is not caused by ethnic, religious or tribal strivings for power. It is the old style of conflict between two States about the demarcation of a frontier which has claimed almost a thousand lives since mid‐June. After the spectacular failure of the US attempt at mediation, the bordering States are worried about a conflict that threatens the stability of the whole of the Horn of Africa.
Khatt& the realities of Somalis: historic, social, household, political & economic
Authors: Green Reginald
                      Herbold
Published: July 2007

This article presents a brief review of khatt; a macro analysis of its roles in the Republic of Somaliland; briefer sketches of divergences of roles in other Somali heartland territories and Kenya concluding with a speculative section on what might be desirable (for Somalis) ways forward. All of these topics are bedevilled by limited prior research, the special pleading strands in much writing, the difficulty in knowing of or securing much of what is known and written and the intensely emotional context of most discourse. The last is not inherently a bad thing — khattmatters. Half of urban household absolute poverty, of farmer cash income and of female instituted divorces are not matters particularly appropriate for mild, disassociated academic curiosity. However, emotion leading to a rush to unanalysed action, and to inventing ‘symbolic truths’, which have meaning but not analytical veridicality, can be the enemy of, just as much as the catalyst toward, the possible.
Harmonisation or differentiation in intellectual property protection? The lessons of history
Authors: DUTFIELD GRAHAM , SUTHERSANEN UMA
Published: July 2007

Developing countries find themselves pressured to harmonise their intellectual property (IP) standards so that they match those of the United States, Europe and Japan. This article provides historical evidence to support the authors’ claim that when developed countries demand that the rest of the world adopt their current IP regulations, developed countries are preventing other countries from adopting appropriate patent and copyright standards for their levels of development. Developed countries thereby deny a freedom to others that they themselves enjoyed when they were developing.
'Do This One For Me, George': Blair, Brown, Bono, Bush and the 'Actor-ness' of the G8
Authors: Pigman Geoffrey Allen , Kotsopoulos John
Published: July 2007

Since the G7/G8 was created at Rambouillet in 1975, it has evolved from being only a venue for diplomacy to becoming a diplomatic actor in its own right. Heads of government, foreign ministers, finance ministers, sherpas, and later other ministers who started meeting and communicating annually at G7 summits, began to generate shared meanings and form a collective identity, even if shifting, that was different and distinct from the identities of the member governments. Participating in the G8 has over time changed the interests of its members, including those of its most powerful member, the United States, across a whole range of issue areas. For example, Britain's leadership of the G8 in 2005 and agenda-setting for the Gleneagles summit pushed poverty reduction in Africa to the fore as a policy priority for G8 members, without which it would have fallen much farther down the foreign policy priority ladder, particularly in Washington. The British G8 agenda facilitated activism by anti-poverty NGOs and eminent person diplomats in raising global social consciousness on the issue and demands for change. The effect of G8 agenda-setting supports the argument that the evolution of multilateral organizations into diplomatic actors in their own right has changed the character of contemporary diplomacy in important ways.
Broadcasting Modernity: Cuban Television, 1950-1953
Authors: Rivero Yeidy M.
Published: July 2007

The essay argues that through television questions about Cuban modernity entailed issues of technology, class, race, gender, morality, sexuality, and geography, as well as the nation's relationship to the United States and to other Latin American countries.
Stability of nanoparticles during semibatch emulsion polymerization of butyl methacrylate, in the presence of methacrylic acid via RSM
Authors: Naderi Nader , Sharifi‐Sanjani Naser , Khayyat‐Naderi Baharak , Agend Farima
Published: July 2007

The size and stability of latex particles in the semibatch emulsion polymerization of butyl methacrylate (BMA), in the presence of 0–10% methacrylic acid (MAA), were investigated. Response surface methodology (RSM), as a design of experiment, was used to obtain a more systematic understanding of the role of emulsifier and MAA in the stability of the particles. The amount of coagulum can be greatly reduced by increasing the concentration of sodium lauryl sulfate (SLS) in the monomer emulsion feed (MEF) and initial reactor charge (IRC). On the other hand, increasing the concentration of SLS in the IRC can result in a decrease of the particles size. According to the experimental data, the yield of reaction can be improved with incorporation of MAA into the emulsion polymers. The size and morphology of particles were obtained by scanning electron microscopy (SEM). FTIR and titration were used to determine the percentage of MAA in the copolymer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Supercapacitor studies of electrochemically deposited PEDOT on stainless steel substrate
Authors: Patra S. , Munichandraiah N.
Published: July 2007

There has been increasing interest on various properties and applications of electronically conducting polymers. Polyethylenedioxythiophene (PEDOT) is an interesting polymer of this type as it exhibits very high ionic conductivity. In the present study, PEDOT has been electrochemically deposited on stainless steel (SS) substrate for supercapacitor studies. PEDOT/SS electrodes prepared in 0.1M H2SO4 in presence of a surfactant, sodium dodecylsulphate (SDS), have been found to yield higher specific capacitance (SC) than the electrodes prepared from neutral aqueous electrolyte. The effects of concentration of H2SO4, concentration of SDS, potential of deposition, and nature of supporting electrolytes used for capacitor studies on SC of the PEDOT/SS electrodes have been studied. SC values as high as 250 F/g in 1M oxalic acid have been obtained during the initial stages of cycling. However, there is a rapid decrease in SC on repeated charge‐discharge cycling. Spectroscopic data reflect structural changes in PEDOT on extended cycling. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Spin Pairing in Spinel‐Type Minerals of Iron (II) and Corresponding Phases
Authors: Frölich F.
Published: July 2007

For interpretations of the results of high‐temperature high‐pressure research which nowadays is used to clarify problems of the upper and deeper Earth's interior, the application of modern solid‐state physics is necessary. Informations from such studies are the better, the better the approximation of laboratory technique to the correspondent conditions of the respective depth is realized and the higher the approach in the description of the real lattice situation in detail can be made which must be analysed. In the latter case, the crystal field approach is to be used, because a lower approximation is completely insufficient. That is discussed in the following for two different situations of the same (spinel) symmetry.
Ein Beitrag zur Lokalisierung von Maskierungs‐ und Passivierungsfehlern von Deckschichten auf Silizium
Authors: Frenzel M.
Published: July 2007

Bei Diffusionsprozessen können Defekte in Deckschichten im oberflächennahen Silizium parasitäre pn‐Übergänge erzeugen, deren Konzentration, Verteilung und Größe Aussagen über die Qualität von Maskierungs‐ und Passivierungsschichten von Halbleiterbauelementen geben. Die Markierung der durch Diffusantendurchbrüche erzeugten pn‐Übergänge erfolgt mit einer Chrom‐Ätzlösung, die Aussagen werden mit Ergebnissen der Kupfer‐ und Silberdekoration verglichen.
Gleitbanduntersuchungen während und nach Verformung der intermetallischen Verbindung MgZn2
Authors: Müller Th. , Krahl H. , Paufler P. , Lamsa A. , Schulze G. E. R.
Published: July 2007

Aus lichtoptischen Messungen der Gleitbanddichten, ‐längen, ‐stufenhöhen und ‐ausbreitungsgeschwindigkeit im Temperaturbereich von 245 bis 427 °C an Oberflächen von plastisch verformten Einkristallen der intermetallischen Verbindung MgZn2 in Abhängigkeit von der Abgleitung werden Schlußfolgerungen für das Verhalten von Versetzungen während der Verformung dieser bei Raumtemperatur spröden Substanz gezogen.
The geometry of fractures caused by cleavage of α‐Al2O3 single crystals
Authors: Bagdasarov H. S. , Berezhkova G. V. , Govorkov V. G. , Kozlovskaya E. P. , Fedorov E. A. , Chernysheva M. A.
Published: July 2007

The possibibity of the existence of cleavage in α‐Al2O3 single crystals has been estimated by elementary structural considerations and has been shown that the {101} and {1120} planes are the more probable cleavage planes. The values of the fracture surface energy measured by Wiederhorn and the estimates of the surface energy made by Hartman confirm this conclusion. In crystals with small numbers of blocks and dislocations and low residual stress we really found a perfect cleavage along the {1011} and {1120} planes. Therefore the existence of the cleavage is defined by the crystal imperfection. It has been shown in what way the orientation of crystals can be visually determined from the direction of cleavage steps.
A Crystallizer for Growing Large Singe Crystals from Solution under Steady‐State Concentration Convection Conditions
Authors: Nicolau I. F.
Published: July 2007

A crystallizer for growing large single crystals from solution under steady‐state concentration convection conditions is described. The crystallizer has only one vessel divided by a drilled plate in two compartments kept at different temperatures. The convection of concentration occurs through the dividing plate between the compartments. The crystallizer was used for growing KDP and TGS single crystals. Mass‐ and heat transfer equations are derived. Growth rate calculations may be carried out using the derived equations. Growth rate measurements of KDP crystals have been performed. The overall heat transfer coefficient for the transfer of heat through the dividing plate is also experimentally determined. Light absorption, ESR and Mössbauer spectra have shown the presence of Fe+2, Cr+3 and Mn+2 ions in the (100) greenish zones of KDP crystals.
Zum Hochtemperaturverhalten der Natriumzeolithe der Faujasitgruppe
Authors: Schmitz W.
Published: July 2007

Die Ergebnisse von Hochtemperatur‐Röntgenuntersuchungen an Zeolithen der Faujasitgruppe (A‐, X‐, Y‐Zeolithe) im Temperaturbereich von 20–1100°C werden dargestellt. Aus NaA‐Zeolith wird zuerst Carnegeit gebildet. Ein Modell wird vorgeschlagen, das nach der Ostwaldschen Stufenregel den polymorphen Übergang Zeolith‐Carnegeit‐Nephelin erklärt.
On the change of dislocation structure during the postdeformation of cold worked molybdenum single crystals at elevated temperature
Authors: Ritschel Ch. , Luft A. , Schulze D.
Published: July 2007

Molybdenum single crystals predeformed at low temperature (T1 ≦ 293 K) exhibit during tensile reloading at T2 = 493 K pronounced work softening accompanied by stress serrations and localized slip. It is shown that the initial state for the development of coarse slip bands is the formation of narrow obstacle‐free slip channels. The change from the homogeneous dislocation structure to the cell structure proceeds in a heterogeneous and discontinuous manner.
Optical anisotropy associated with growth striation of yttrium garnet, Y3 (Al, Fe)5O12
Authors: Kitamura K. , Komatsu H.
Published: July 2007

The optical anisotropy associated with growth striae of yttrium garnet, Y3(Al, Fe)5O12, was studied in terms of optical microscopy and EPMA analysis. It turned out that the lattice mismatch due to the compositional change at the growth striae gives rise to stressbirefringence. The result can be applied to compositional characterization of garnet single crystal by determining the vibration directions of polarized rays under a microscope.
Two parameter kinetic equation of size dependent crystal growth
Authors: Rojkowski Z.
Published: July 2007

The previously proposed hyperbolic, three parameter empirical model of size dependent crystal growth can be reduced to the two parameter one of the form

This simplification reduces dimension of the least squares correlation of crystal size distribution in MSMPR crystallizer thus saving amount of calculations with a negligible loss of accuracy estimated by means of the mean residual square deviation. The additional advantage is that a differential balance of crystal number in MSMPR crystallizer can be solved analytically for the simplest case of the exponential function of secondary nuclei size distribution. Correlations for single experiment with ammonium alum are presented.
Würfeltexturbildung in Nickel‐Eisen‐Kobalt‐Legierungen
Authors: Wibbeler H. , Rassmann G. , Schatt W.
Published: July 2007

Es wird über Texturuntersuchungen an Co‐legierten weichmagnetischen Fe‐Ni‐Basislegierungen, die einer kombinierten mechanisch‐thermischen Behandlung unterzogen worden waren, berichtet. Während für die binären Systeme NiFe und NiCo die Ausbildung einer scharfen Würfeltextur seit längerem bekannt ist, wurde eine solche für ternäre NiFeCo‐Legierungen bisher als nicht möglich und Co als ein die Würfellagebildung behinderndes Element angesehen. Wie jedoch die Ergebnisse zeigen, läßt sich auch an ternären Legierungen mit Ni‐Gehalten von 45 bis 50% und Co‐Anteilen bis zu etwa 25% eine scharf ausgeprägte Würfellagen‐Rekristallisationstextur erzielen.
α‐substituted Phosphoryl Compounds (I). The Crystal and Molecular Structure of Diethyl[5,6‐dichloro‐1,3‐benzodioxol‐(2)]‐phosphonate, C11H13O5PCl2
Authors: Kulfe S. , Seidel I.
Published: July 2007

Diethyl[5,6‐dichloro‐ 1,3‐benzodioxol‐(2)]‐phosphonate crystallizes in the triclinic space group P l̄ with two molecules per unit cell. The lattice parameters are a = 11.716 Å, b = 8.471 Å, c = 7.644 Å; α = 82.47° β = 95.81°, γ = 95.89°. With X‐ray diffraction data collected on an automatic four circle diffractometer, the crystal structure was solved by direct methods and refined by least squares methods to an R value of 0.12 for 2374 measured reflections. The crystal used was im perfect. The substance is a derivative of acetales of formyl phosphoneacid esters. The aim is to find a correlation between the geometry of the structure and NMR data.
Liquid‐phase epitaxy of AlGaAs heterostructures on profiled substrates
Authors: Andreyev V. M. , Egorov V. V. , Syrbu A. V. , Trofim V. G. , Yakovlev V. P.
Published: July 2007

A method of fabrication of planar local structures using the selective epitaxial growth of GaAs and AIGaAs layers from liquid phase on profiled GaAs substrates was developed. The planar regrowth of the recesses formed in GaAs substrates by local etching was performed using the anisotropy of epitaxial growth rates and also by providing the uniformity of mass flow to the surface of local epilayer. The developed method of localized structures fabrication was used for improving the characteristics of discrete light emitting diodes — LED and for fabrication of DLE monolithic arrays.
Growth and properties of single crystals of FeTi
Authors: Liebertz J. , Stähr S. , Haussühl S.
Published: July 2007

A Single crystal of FeTi with a diameter of ca 34 mm and a length of ca 48 mm has been grown from a quasi‐stoichiometric melt with an excess of 1% titanium employing the Bridgman technique. Experiments with the Czochralski technique were not successful. The only crucible material sufficiently resistent against reaction with the melt is electrographite. Elastic and thermoelastic constants were determined by means of ultrasonic methods. FeTi and α iron possess a similar bulk compressibility, thermal expansion, and thermoelastic constants. The longitudinal elastic resistance c11 of FeTi supersedes that of α iron by an amount of ca 30%.
Internal defect structures of olivine crystals
Authors: Inoue T. , Komatsu H. , Takei H. , Ozima M. , Shimizu M.
Published: July 2007

Defect structures of olivine crystals (Czochralski grown forsterite, flux grown forsterite and natural olivine) were studied by means of chemical etching method, X‐ray topography and light scattering tomography. Two etchants were used for revealing the dislocation sites; one is the etchant described by WEGNER, CHRISTIE, another is that by DESAI, JOHN. It was found that great care was needed in identifying dislocation sites using these etchants since they attack the impurity sites as well as dislocation sites. The results obtained are as follows; (1) The Czochralski grown forsterite and flux grown forsterite were free from sub‐boundaries and the dislocation density was smaller than that of a natural olivine. There existed many sub‐boundaries in the natural olivine. (2) X‐ray topographic study showed that (i) the dislocation lines of the Czochralski grown forsterite consisted mainly of straight segments nearly parallel to the low index direction, whereas (ii) no dislocation lines corresponding to the etch pits were observed in the flux grown forsterite. (3) The study by light scattering tomography showed that there existed various types of scattering centers in these olivine crystals and that the density and shape were different among them.
Stearic acid polymorphs in correlation with crystallization conditions and solvents
Authors: Garti N. , Wellner E. , Sarig S.
Published: July 2007

Stearic acid has been crystallized from various organic solvents at different crystallization conditions. — The crystal structure modifications, A, B or C of the fatty acid are correlated to the solvent properties and depend on the interplay between the effect of the crystallization conditions and the solvent/solute interactions.
EPR Studies of defects in silicon
Authors: Weber E.
Published: July 2007

Electron and neutron irradiated, plastically deformed silicon has been studied by EPR. Irradiation resulted in a strong decrease of the EPR spectra produced by the deformation and in the appearance of a new EPR center at dislocations. Thermal annealing lead to a reestablishment of the formerly present dislocation spectra. As most probable explanation is proposed a change of the dislocation strain field by irradiation induced point defect iclusters. – EPR investigations of iron in boron doped Si demonstrated the pairing of all nterstitial iron in FeB pairs during room temperature storage. Thermal treatment at temperatures higher than 100°C lead to the reappearance of Fe. Therefore the time limiting factor for the annealing of FeB pairs should be the precipitation of interstitial iron.
On the driving force in phase transitions: Calculation of chemical potential differences
Authors: Bohm J.
Published: July 2007

Chemical potential differences for phase transitions of monocomponent and two‐component systems are calculated by Taylor expansions at phase equilibrium. The derived expressions (put in frames in the text) are governed by meaningfull physico‐chemical entities.
Mechanism of condensation of heteroepitaxial A3B5 layers pulse of moderate power
Authors: Sheftal R. N. , Cherbakov I. V.
Published: July 2007

The mechanism of condensation of heteroepitaxial layers in laser deposition was studied on GaAs films on NaCl. Films were deposited in a superhigh vacuum using laser pulses of moderate power. Pulsed deposition proved to be more suitable for nucleation and growth than continuous deposition. However in this case it is important to compare the number of atoms deposited per pulse and the number of preferential adsorption centres in the substrate temperature of 310 °C. The density of dislocations in the films was about 109 cm−2. The main reasons for the dislocations are the excess of low volatile component and thermal stresses. Using a laser with quantum energy higher than the energy gap of the deposited semiconductor GaAs, which provides congruent evaporation, and making an additional deposition of As, we could reduce dislocations to 107 cm−2. A mechanism is proposed to explain the reduction of temperature in single crystal growth under laser deposition: high energy ion component of laser plasma gives rise to orienting defects on the substrate surface, and these defects determine epitaxial growth.
Effect of buffer layers on the dislocation structure of heteroepitaxial systems
Authors: Bolkhovityanov Yu. B. , Vaulin Yu. D. , Gutakovsky A. K. , Stenin S. I. , Yudaev V. I.
Published: July 2007

Transmission electron microscopy (TEM) as well as X‐ray topography (XRT) and X‐ray diffractometry have been used for investigation of the structure of the LPE heteroepitaxial system In0.05Ga0.95As‐InyGa1−yAs1−xPx‐GaAs(111) A. A critical value of the lattice misfit has been shown to exist at the metallurgical boundary ((Δa/a)* ≈ 10−3) which results in the change of the film nucleation and growth mechanism as well as the change of misfit dislocations (MDs) generation mechanism. With (Δa/a)0 > (Δa/a)* the nucleation and growth mechanism is mixed: island growth at the first stages of growth and layer‐by‐layer growth at large thicknesses. MDs are created in an “island film” developing a non‐ordered dislocation network. The density of threading dislocations (Nd) is ∼ 108 cm−2. With (Δa/a)0 < (Δa/a)* there is layer‐by‐layer mechanism of film's nucleation and growth from the very first stages of crystallization. MDs are injected into continuous layer along the inclined slip planes {111}, thus forming a regular three‐dimensional grid of MDs. Nd is less than 106 cm−2 in the case. A model of dislocation structure formation in heterolayers has been proposed. Within the frame of this model the two critical values of phosphorus concentration in the quaternary melt have been quantitatively determined. These are corresponding to the change of MD generation mechanism. The expected values of Nd for (Δa/a)0 > (Δa/a)* and (Δa/a)0 < (Δa/a)* have been theoretically determined.
The effect of solvents and crystallization conditions on crystal habit of cholesterol
Authors: Garti N. , Karpuj L. , Sarig S.
Published: July 2007

The effect of various organic solvents as well as the crystallization conditions on the crystal habit of anhydrous cholesterol have been studied. Both plates and needle‐like crystals can be obtained in a particular solvent depending on the degree of supersaturation of the solution. However, the crystals grown at about the same supersaturation, from different solvents, show differences in their habit indicating dependence on the solvent‐solute interaction. Thus, it is advisable not to identify needle‐like crystals with anhydrous‐cholesterol and plates with mono‐hydrate cholesterol without specifying the crystallization conditions. A prediction on the crystal habit length to width ratios can be made using those parameters.
The Analysis of Growth Kinetics in Liquid Phase Electroepitaxy (LPEE) of binary systems
Authors: Ivashchenko A. I. , Kopanskaya F. Ya.
Published: July 2007

Growth kinetics of binary systems in liquid phase electroepitaxy (LPEE) is analysed in terms of one‐dimensional forced diffusion with initial and boundary conditions reflecting the features of various modifications of LPEE. Electromigration of a solute in the melt and the Peltier effect at the interface between liquid and solid phases induced by electric current are taken into account.

Three LPEE modifications are considered here. The first modification is when liquid phase is constantly riched due to dissolution of the semiconductor cathode. The second one‐when liquid phase is constantly riched from vapour phase by controlled vapour pressure. The third one‐when any source of the melt enrichment is absent.

This consideration is limited by the assumption that the deviation of the solution heighs or convection doesn' affect the steady‐state temperature at the interfaces between solid and liquid phases. The obtained expressions for growth rate show that quantitative results of the epitaxial growth are closely connected with a concrete method of LPEE realization.
The precipitation of sparingly‐soluble metal salts from aqueous solution: Heterogeneous nucleus numbers at low to intermediate supersaturation
Authors: Packter A. , Alleem A. , Chauhan P. , Uppaladini S. C.
Published: July 2007

The precipitation of series of alkaline‐earth metal and transition hydroxides, sulphates, chromates and molybdates, hydrogen phosphate carbonates, oxalates and ‘oxinates’ were studied in aqueous solution of low to intermediate supersaturation. Heterogeneous nucleation probably occurred onto micro‐crystalline particles of some siliceous mineral (of the trigonal, hexagonal or cubic system), dispersed in the solution. The heterogeneous nucleus numbers for these precipitations then depended on the rates of the heterogeneous nucleation onto these substrates and the rates of the mononuclear growth of nuclei to crystallites (during the induction periods). Generally, Nhet values in polypropylene and glass beakers, at low supersaturation, varied from 104 to 1013 dm−3: the Nhet values then increased slightly with concentration and supersaturation according to the relation Nhet = KNβ, where KN is a function of the metal salt surface energy and an ‘epitaxy’ factor; β = 0.4–0.5. In turn, at any supersaturation, log Nhet = log N + Fσ, where N and F were constants for any precipitation: Nhet values then increased from 104 to 108 times for increase in σ from 50 to 150 mJ m−2.

At any supersaturation and surface energy, Nhet values increased in the order monoclinic < orthohombic < tetragonal < trigonal crystals.
An evaluation of quarterly national institute forecasts
Authors: Holden K. , Peel D. A.
Published: July 2007

This paper examines the quarterly forecasts by the U.K. National Institute of Economic and Social Research of the rate of inflation and the change in real gross domestic product and its components for horizons of one to four quarters ahead in the U.K. The forecasts are tested to see if they satisfy three implications of the rational expectations hypothesis: unbiasedness, efficiency and consistency. Explicit consideration is given to the information set available when the forecasts are made. In general, the data are consistent with the rational expectations hypothesis and our results provide encouragement for the view that aggregate expectations will meet the ex post requirements of rationality.
An examination of the accuracy of judgemental confidence intervals in time series forecasting
Authors: O'Connor Marcus , Lawrence Michael
Published: July 2007

This paper examines the accuracy (calibration) of judgemental and selected statistical confidence intervals in time series forecasting. Using the forecasts and forecast errors produced by the deseasonalized single exponential smoothing method, three statistical intervals were produced utilizing three assumptions about the distribution of errors: the normal distribution, the empirical distribution and the distribution based on the Chebyshev inequality. Using 33 real‐life time series, results indicated that the judgemental confidence intervals were initially excessively overconfident, thus confirming the finding of Lichtenstein et al. (1982). However, calibration of the judgemental intervals improved considerably with feedback, and was found to be influenced by the degree of forecasting difficulty of the series.
The application of numerical models to assess dispersion and deposition in the event of a nuclear accident
Authors: Apsimon Helen M. , Wilson Julian
Published: July 2007

Numerical models have been widely used in risk studies to estimate how hypothetical releases of radionuclides will disperse and lead to exposure of the population. In this context large numbers of possible scenarios are treated; absolute accuracy in simulating each particular situation is not necessary as long as the correct statistical distribution of consequences emerges. Since the Chernobyl accident there has been more interest in the use of numerical models as tools to assist in real‐time in emergency procedures if and when a nuclear accident occurs. However, the use of models in a real situation is distrusted by many people, who feel that the only way to assess an emergency situation is by making radiological measurements. This paper addresses uncertainties involved in modelling and argues that a combination of both approaches should be employed, using numerical modelling as an aid in intelligent interpretation of measurements, and suggesting priorities for international exchange of radiological data.
Uncertainty propagation and speculation in projective forecasts of environmental change: A lake‐eutrophication example
Authors: Van Straten Gerr T. , Keesman Karel J.
Published: July 2007

The issue of whether models developed for current conditions can yield correct predictions when used under changed control, as is often the case in environmental management, is discussed. Two models of different complexity are compared on the basis of performance criteria, but it appears that good performance at the calibration stage does not guarantee correctly predicted behavior. A requirement for the detection of such a failure of the model is that the prediction uncertainty range is known. Two techniques to calculate uncertainty propagation are presented and compared: a stochastic first‐order error propagation based on the extended Kalman filter (EKF), and a newly developed and robust Monte Carlo set‐membership procedure (MCSM). The procedures are applied to a case study of water quality, generating a projective forecast of the algal dynamics in a lake (Lake Veluwe) in response to management actions that force the system into a different mode of behavior. It is found that the forecast from the more complex model falls within the prediction uncertainty range, but its informative value is low due to large uncertainty bounds. As a substitute for time‐consuming revisions of the model, educated speculation about parameter shifts is offered as an alternative approach to account for expected but unmodelled changes in the system.
System identification and validation for output prediction of a dynamic hydrologic process
Authors: Jakeman A. J. , Thomas G. A. , Dietrich C. R.
Published: July 2007

The paper presents an identification procedure for a dynamic model of am hydrologic process. The process involves solute transport in streams subject to aquifer interaction and unsteady flows and the intended use of the model is prediction. Detailed assumptions and results are provided to illustrate the level of comprehensive analysis required to assess model adequacy. The assessment procedure easily generalizes to any dynamic model which is linear‐in‐the‐parameters. As a fundamental tool, instrumental variable algorithms can be adopted which have a number of attractive features. These algorithms make both model‐order identification and specification among alternatives a straightforward task. They are known to be consistent estimators in the presence of a wide class of errors. It is seen that they can be made stable and robust in the presence of data outliers. Instrumental variable algorithms can also be used which are asymptotically efficient and provide a covariance matrix of parameter estimates. The paper shows how they aid the quantification of predictive uncertainty and investigates the validity of the underlying assumptions. Further, it illustrates that, when instrumental variable algorithms are used in recursive mode, they can be used not only as an additional tool to access model inadequacy but also as an aid to model improvements.
Analysis and prediction of the population in Spain: 1910–2000
Authors: Garcia‐Ferrer Antonio , Hoyo Juan Del
Published: July 2007

The starting hypothesis of this paper was the actual occurrence of important interactions between demographic and socio‐economic factors when trying to reach population forecasts that may be more efficient than those obtained by mere extrapolative methods. In order to be able to implement this approach to the Spanish case it has been necessary to reconstruct first the Spanish population series by age and sex groups from 1910 to 1980. Later, we proceed to obtain population forecasts using alternative modeling strategies and comment on the potential problems that the new demographic situation may have for future public policy.
On the problem of forecasting prior to ‘price’ control and decontrol
Authors: Revankar Nagesh S.
Published: July 2007

The paper treats the forecasting problem in the context of a demand or supply equation, when the explanatory variable z1 = xi′z + et – the ‘price’ variable – is controlled (exogenous) in the forecast period – Case A; or vice versa – Case B. In either case, at least some parameters need to shift in value from the sample to the forecast period, and the forecasts in general need to use prior information on the forecast period values of such parameters. The paper assumes that shifts occur only πz, V(et), and the reduced‐form parameters involved in the exogeneity restriction. When V(et) is the only parameter to shift, neither case calls for any prior information. In other instances, Case A is less demanding than Case B in terms of prior information needs. Among other things, the paper draws attention to the relevance of the distinction between a conditional forecast and a controlled forecast in Case B.
Domestic and international macro‐economic effects of german economic and monetary union simulations on QUEST
Authors: Horn G. A. , Scheremet W. , Zwiener R.
Published: July 2007

This paper addresses the impact of German economic and monetary union on the world economy. The basic question is if positive growth effects of increased German imports dominate the negative forces caused by rising interest rates and varying exchange rates. From simulations on the multi‐country QUEST model which incorporates the major bilateral trade selections one can draw the conclusion that the former impact is stronger than the latter. Hence, in general, the world economy benefits from German unification.