bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural Morphing using Piezoelectric Modulation of Joint Friction
Authors: Agarwal Sandeep
Published: December 2006

An innovative approach to morphing/reconfiguration in flexible structures through friction control in joints is proposed and theoretically explored in this study. The customary method of morphing structures through embedded actuators suffers from the fact that actuators have limited authority and high density, and that the presence of integrated/ embedded actuation devices results in stress concentrations in the substrate. As opposed to using induced elastic strain to cause morphing in elastic structures, the concept presented utilizes piezoelectric control of friction for locking/unlocking in structural joints, and sensors for sensing the structural vibration state in conjunction with naturally occurring or excitation vibration energy, to morph the structure under control. The applications of this concept are not limited to morphing alone but in a broader sense, encompass fields of reconfigurable and fault/damage tolerant structures, having characteristics typically desirable in space structures such as deployable antenna reflectors and space cranes. The proof of this concept is theoretically demonstrated using a single flexible beam (n=1) free at one end and connected to a semi-active revolute joint at the other. Based upon the commanded state of the joint, the beam can switch between a cantilevered and a pinned-free configuration, respectively. The beam is to be reconfigured to a desired azimuth angle in the least time by providing an initial excitation and controlling joint locking and unlocking timing in an optimal manner. The control actions for the timely locking and unlocking of the semi-active joint are determined analytically and verified numerically by using a finite element model simulation using DYMORE. A design of a semi-active joint model capable of providing the desired locking/unlocking action is proposed.
Participatory Design in Health Sciences: Using Cooperative Experimental Methods in Developing Health Services and Computer Technology
Authors: Clemensen Jane , Larsen Simon B. , Kyng Morten , Kirkevold Marit
Published: December 2006

Participatory design (PD) is a research approach to the development of technological solutions to real-world problems, an approach that shares manyconcerns and some of its roots with action research. In this article, the authors discuss their experience in conducting a PD research project intended to develop a technological and a related organizational intervention to support the treatment of foot ulcers for people with diabetes at home. They provide a historical overviewof the PD approach and a description of how they used it in their researchstudy. They describe their experience in conducting the research, including the participants' responses, the outcomes of the research, and the challenges confronted in bridging the practical and disciplinary issues that arose. In the conclusion, they propose that PD holds potential as a research approach that might effectively merge computer technology and health-related interventional research.
Challenges in Approaching Metasynthesis Research
Authors: Bondas Terese , Hall Elisabeth O. C.
Published: December 2006

The overall aim of this study was to contribute to the development of metasynthesis through an analysis of the challenges involved. The study grew out of the critique of qualitative metaresearch raised by current developers of metamethodologies. Different views on the application of methodologies have emerged in the literature, contributing to confusion and ambiguity concerning the challenging questions of what, why, how, and who in metasynthesis research, which might increase the risk of misunderstanding. The roots of metasynthesis research are seen as multifaceted and influencing the development of the methods in different directions. The primary worth of metasynthesis is theoretical and/or methodological development (synthesis) combined with the potential for reflection: going beyond and behind the studies (meta). Metasynthesis research has also the potential to raise questions of research collaboration, culture, and language.
Promoting Public Health Messages: Should We Move Beyond Fear-Evoking Appeals in Road Safety?
Authors: Lewis Ioni M. , Watson Barry , White Katherine M. , Tay Richard
Published: December 2006

Road traffic injury is one of the most significant global public health issues of the 21st century. The extent to which negative, fear-evoking messages represent effective persuasive strategies remains a contentious public and empirical issue. Nevertheless, negative, fear-based appeals represent a frequently used approach in Australasian road safety advertising. The authors conducted a series of focus groups with 16 licensed drivers to explore the potential utility of appeals to emotions other than fear. More specifically, they sought to explore the utility of positive emotional appeals, such as those incorporating humor. The themes emerging from the qualitative analysis suggested that both emotion and the provision of strategies are key components contributing to the overall persuasiveness of a road safety advertisement. Overall, it appears there is support for researchers and health advertising practitioners to provide further attention to the role that positive emotional appeals might play in future campaigns.
Exploring Food Security With Collective Kitchens Participants in Three Canadian Cities
Authors: Engler-Stringer Rachel , Berenbaum Shawna
Published: December 2006

Collective kitchens are small groups of people who pool their resources to cook large quantities of food. With the help of semi–participant observation and in-depth individual interviews, this study is an exploration of participants' perceptions of changes in food security since becoming involved in a collective kitchen. Several important themes emerged, including Increased Variety, Making Ends Meet, and Comparisons to Food Banks. Participants in groups that cooked large quantities of food (upwards of five meals monthly) reported some increases in their food resources. Participants also reported increased dignity associated with not having to access charitable resources to feed their families. Some participants reported decreased psychological distress associated with food insecurity. Overall, participants reported increases in food security; however, collective kitchens are not a long-term solution to the income-related food insecurity experienced by many Canadian families.
Donning Wigs, Divining Feelings, and Other Dilemmas of Doing Research in Devoutly Religious Contexts
Authors: Schweber Simone
Published: December 2006

By juxtaposing the experiences of conducting research at two schools, one a Charismatic, evangelical, fundamentalist Christian school, the other, an ultra-orthodox Hasidic Jewish girls’ school, the author discusses prevailing notions of subjectivity, arguing that postmodern and postpositivistic models of subjectivity apply, but that their applications are best imagined as profoundly context driven.
Social Semiotics and Fieldwork
Authors: Vannini Phillip
Published: December 2006

Drawing from recent analytical developments in semiotics and postmodern ethnography, this article exposes and assesses the combination of social semiotics and fieldwork as a form of qualitative inquiry. Approaches to semiotics and fieldwork are not new—structural ethnographers in cultural anthropology and structural interactionists in sociology and communication studies have previously laid the foundations for the integration of formal methods of analysis and inductive approaches to data collection—yet, as this article argues, structuralism’s limitations have hampered the growth of semiotics within qualitative inquiry. By presenting social semiotics as a viable alternative to structural semiotics, by describing in clear pedagogical fashion how social semiotics can be used as a research strategy, and by exposing its potential for applicability, this article attempts to bring sociosemiotic ethnography to the forefront of contemporary qualitative inquiry.
Shear Characterization of Sandwich Core Materials Using Four-point Bending
Authors: Juntikka Rickard , Hallstrom Stefan
Published: December 2006

A new shear test method for sandwich core materials is proposed and evaluated. Sandwich beams are loaded in four-point bending, and the shear deformation is measured with two rotary sensors. Conditions of idealized sandwich theory are assumed to prevail, and the accuracy of the proposed methodology is thus dependent on a few mechanical and geometric relations between the sandwich constituents. The stress-strain responses for two polymer foam core materials, one relatively brittle and one relatively ductile, are extracted and compared with results from single-block shear tests of the same material batch. The new method provides several benefits with respect to the block shear test. It does not suffer from extreme stress concentrations and the specimens are tested under in-service conditions. Problems arise, however, for the ductile material, predominantly related to large deformations during the test eventually resulting in bending failure of the face sheet instead of shear failure of the core.
Effects of income, assets and age on the vacationing behavior of US consumers
Authors: Peterson Mark
Published: December 2006

This study uses multinomial logistic regression analysis of a nationally-representative database of US consumers’ vacationing to better understand the relative effects on vacationing behavior of economic variables (such as annual income and liquid assets), when compared to age-group effects. In this extensive research, the effects of the economic variables dominated the effects of the age-group variable. When considering possible differences across age-groups, in-depth analysis using five age-groups disclosed uniformity across three age groups covering a 40-year age range from 35 to 75 years. Notably, this age range included the Baby Boomers, as well as two groups of Seniors. These results suggest that vacation researchers should be careful to not use the ‘Senior’ classification too loosely. Seniors under the age of 75 manifest vacationing behaviors in a way similar to Baby Boomers aged 35-55. These younger Seniors manifest much different vacationing behavior compared to Seniors aged 75 and older.
Prehospital advanced airway management for trauma in the United Kingdom: how, when and by whom?
Authors: Hickman J
Published: December 2006

Advanced airway management in the prehospital arena remains controversial. This paper aims to explore some of the evidence and options available and propose a way forward. Options for provision of, and training in, pre-hospital emergency anaesthesia are explored and alternative strategies are discussed. Where classical rapid sequence induction of anaesthesia proves impractical for operational reasons or due to lack of facilities, training opportunities or skills maintenance, a potential ‘silver standard’ is suggested as an alternative.
Head and neck injuries in football (soccer)
Authors: Al-Kashmiri Ammar , Delaney J Scott
Published: December 2006

The incidence for concussions in football (soccer) is equivalent to other contact sports such as American football and ice hockey. The risk of concussion is increased in goalkeepers, females and perhaps young players. Head to head contact between athletes is the most common mechanism for concussion, while heading does not appear to be a frequent cause. Research is providing evidence that neck muscle development and protective headgear may play a role in the prevention of concussions. The presence and pathophysiology of a chronic encephalopathy secondary to a cumulative subconcussive blows obtained in football is still controversial. Neck injuries are not as common as head injuries and are not frequently reported in the literature. The biomechanics of neck injuries are different between children and adults which may account for the different types of injuries in these populations. Spinal cord injuries are rarely seen in football and are usually associated with major fractures/dislocations.
The clinical effectiveness of pre-hospital intravenous fluid replacement in trauma patients without head injury: a systematic review
Authors: Dretzke Janine , Burls Amanda , Bayliss Sue , Sandercock Josie
Published: December 2006

Traditionally, the management of bleeding trauma patients has included early rapid fluid replacement on scene. However, evidence shows that a delay to definitive treatment (control of bleeding) may be harmful and UK policy advocates minimal delay on scene with intravenous fluids being administered in transit to hospitals. This paper systematically reviews the evidence for administering fluids in pre-hospital trauma patients with no head injury. Randomized controlled trials comparing immediate and delayed fluid replacement were sought using formal search strategies. Study selection, quality assessment and data extraction were performed independently by two reviewers using pre-defined criteria. We found no evidence to suggest that pre-hospital fluid administration is beneficial. There is some evidence that it may be harmful and that patients do comparatively well when fluids are withheld. However, this evidence is not conclusive, particularly for blunt trauma, and is not sufficient to disprove current UK policy, which recommends hypotensive resuscitation.
When the policy becomes the problem
Authors: Steen Sara , Bandy Rachel
Published: December 2006

In this article, we document a shift in public conversations about punishment in the United States that has occurred as a result of a collision between the principles of punishment that have dominated public policy for the past three decades and the fiscal realities of the 21st century. Over the past three decades, legislators have created a conversation in which the inclusion of principles other than retribution and revenge is virtually impossible. This absence of practical considerations has led to policies that are, in many cases, outrageously expensive. During the past five years, many state governments have seen their expenses grossly outpace their revenues, leaving legislators now to face a reality in which the ‘Get Tough’ policies of the 1980s and 1990s are no longer economically sustainable. We argue that the changing fiscal situation provides a context in which the rhetoric of punishment is finally open to change, and we document some of the rhetorical shifts that occur.
Public-empowering justice
Authors: Gordon Diana R.
Published: December 2006

In mature democracies citizens are being gradually empowered to make important decisions about how to handle crime and disorder and to assume an active role in making their communities safer. Do the justifications for this partial shift away from the commitment to adversarial, state-centered criminal justice apply to democratizing countries? Viewed individually, the arguments for public-empowering justice in transitional states are all quite partial. But they can be creatively combined within a framework that has relevance for a number of countries, especially if the argument from democracy incorporates a deliberative perspective. Significant institutional barriers remain, however, as illustrated by the post-apartheid South African state's retreat from its initial interest in community policing, lay assessors in criminal trials, and community courts.
Community Health Navigators for Breast- and Cervical-Cancer Screening Among Cambodian and Laotian Women: Intervention Strategies and Relationship-Building Processes
Authors: Ngoc Nguyen Tu-Uyen , Tanjasiri Sora Park , Kagawa-Singer Marjorie , Tran Jacqueline H. , Foo Mary Anne
Published: December 2006

In recent years, there has been a growing number of programs employing health navigators to assist underserved individuals in overcoming barriers to obtaining regular and quality health care. This article describes the perspectives and experiences of community-based health navigators in the Cambodian and Laotian communities involved in a REACH 2010 project to reduce health disparities in breast and cervical cancer among Pacific Islander and Southeast Asian communities in California. These community health navigators, who have extensive training and knowledge about the cultural, historical, and structural needs and resources of their communities, are well equipped to build trusting relationships with community members traditionally ignored by the mainstream medical system. By comparing the different social support roles and intervention strategies employed by community health navigators in diverse communities, we can better understand how these valuable change agents of the health workforce are effective in improving health access and healthy behaviors for underserved communities.
Independent design and conduct of clinical trials
Authors: Yusuf Salim , Bosch Jackie
Published: December 2006

Randomized clinical trials (RCTs) have justifiably become the cornerstone for the evaluation of virtually any kind of intervention: drugs, surgical or diagnostic procedures, behavioural modifications, health policies and even systems of care. This commentary focuses on two issues related to independence in clinical trials: first, the independence to ask important questions, and second, independence from bias in the conduct, analysis and reporting of trials, which can lead to misleading conclusions. The most frequent type of RCT are those evaluating therapies, and much of this commentary will be focused on issues relevant to such trials, although the principles apply generally.
Rethinking Educational Reform
Authors: Goldspink Chris
Published: December 2006

This article critically examines two sets of ideas that have influenced educational reform in the recent past: managerialism and market approaches. It is argued that while each can be demonstrated to have led to useful change, neither provides a basis for future improvement in education. A recent example of change within the State School sector of South Australia is used to provide a grounding point for the development of a set of principles to guide future reform. These principles draw on a well-established set of ideas: that of educational systems as ‘loosely coupled’ and recent advances in the application of complex systems concepts to organizational management. These concepts, and the South Australian example, suggest the potential benefits from using self-organizational properties to improve institutional learning. Unlike the ‘rationalist’ management and market approaches, the alternative model emphasizes the need for a focus on people, relationships and learning rather than structures and centrally determined standards for conformance.
Educational Reform
Authors: Hoyle Eric , Wallace Mike
Published: December 2006

This article adopts irony as a frame for understanding some of the consequences of the reform movement in the UK. A distinction is drawn between the ironies that are endemic in all organizations and rooted in ambiguities and dilemmas, and the ironies that specifically flow from the disjunction between central policies and the contingent circumstances of individual schools. A further distinction is made between the ironies of policy and the ironies of practice, the latter characterized by the strategies used by headteachers and teachers as they adapt policy to practice and as they represent these adaptations as fulfilling accountability requirements. A case is made for principled infidelity as a component of temperate leadership and management which acts as an antidote to overwhelming policy initiatives and the excesses of managerialism to which these give rise.
Reports from the Front Line
Authors: Bottery Michael
Published: December 2006

This article investigates the perceptions of English headteachers to questions addressing the setting of goals and the effects of external pressure on headteachers. The research utilizes semi-structured interviews with headteachers from a variety of contexts. These interviews were used to write individual headteacher ‘portraits’, which were then re-examined to answer the questions generated. The findings suggest that: (1) contrary to current literature, it is not sensible to suggest either that headteachers have considerable flexibility in how they approach their work, nor that they are so ground down by legislative imperatives that they can do little more than be agents of implementation; (2) appropriate CPD should be individually tailored to the contexts and personalities of the individuals involved; (3) English headteachers may be so focussed on the local that they may fail to have a sufficient grasp of the global and national changes around them to fully lead the profession in responding appropriately to these.
Recognition of imogolite structures in allophanic clays by infrared spectroscopy
Authors: Farmer V. C. , Fraser A. R. , Russell J. D. , Yoshinaga N.
Published: December 2006

Imogolite structures in allophanic clays can be recognized and semi-quantitatively estimated by an absorption band at 348 cm−1. Allowance can be made for interference by aluminous dioctahedral layer silicates present in small amounts.
Halloysite in some soils from north-east Scotland
Authors: Wilson M. J. , Tait J. M.
Published: December 2006

X-ray diffraction and electron microscopy show that halloysite occurs widely in soils derived from a variety of parent rocks (granite, gabbro, schist and slate) in north-east Scotland. Both tubular and non-tubular forms are observed, the latter being characterized by electron diffraction patterns with 001 reflection either absent or very weak and diffuse. Clay fractions from a poorly drained profile separated without prior drying of the soil samples contain essentially dehydrated halloysite at the surface, this becoming progressively more hydrated with depth. Since halloysite occurs extensively in soils of widely varying drainage class the mineral is probably not the result of recent soilforming processes but may have originated during Tertiary or interglacial weathering.
Modalités des néogeneses dans des systèmes hétérogènes renfermant des phases peu solubles
Authors: Besson H. , Caillère S. , Hénin S.
Published: December 2006

Le dispositif expérimental utilisé comporte une série de sacs à dialyse renfermant des gels de silice, d'alumine, isolés, mélangés ou coprécipités et un sac renfermant un de magnésium hydraté ou un précipité d'hydroxyde de magnésium.

En fin d'expérience, les matériaux ont été recueillis et étudiés afin d'établir leur composition chimique et minéralogique.

On constate que, lorsque la silice a beaucoup migré, le magnésium a peu migré et vice versa. En effet, les rapports

et R(MgO) calculé de la méme façon sont relies approximativement par la formule suivante:

Si on considere les minéraux formés, on constate que, pour les valeurs élevées de R(SiO2), l'alumine évolue sous forme d'hydroxyde alors que, pour les fortes valeurs de R(MgO), on tend à obtenir l'hydrotalcite.

Les auteurs proposent une interprétation de ces différents comportements. Le fait le plus remarquable est que pour les très fortes values de R(MgO), on se trouve dans les conditions de l'adsorption.

Ces résultats signifient que, dans un système hétérogène renfermant des constituants peu solubles, il existe au voisinage de ces derniers des conditions de genèse particulières.
Polymerisation de benzene en polyparaphenylene dans une montmorillonite cuivrique
Authors: Stoessel F. , Guth J. L. , Wey R.
Published: December 2006

Lors de l'étude des produits d'adsorption du benzène sur une montmorillonite cuivrique partiellement déshydratée (P4O10 et vide), la polymérisation du benzène en polyparaphénylène a été mise en évidence. Cette polymérisation a lieu au cours de cycles de déshydratation — adsorption — réhydratation à l'air, à partir de la forme rouge du complexe montmorillonite — cuivre II — benzène. Le polymère, caractérisé par spectroscopie infra-rouge, est formé dans l'espace interfoliaire de la montmorillonite comme le montrent les diagrammes de rayons X. Les mécanismes réactionnels possibles sont discutés.
Influence des substances humiques sur les proprietes des argiles
Authors: Chassin P. , Nakaya N. , Le Berre B.
Published: December 2006

L'étude de l'adsorption des acides fulviques, des acides humiques ou de leur mélange par la montmorillonite saturée avec du calcium ou de l'aluminium permet de: (i) définir les mécanismes de fixation des substances humiques en phase aqueuse; (ii) préciser une orientation différente des moécules adsorbées selon leur nature; acides fulviques ou acides humiques; (iii) caractériser une forte sélectivité d'adsorption pour les molécules les moins polymérisées.

A partir de ces résultats, il est montré que, d'une part, la flexibilité des molécules est un paramètre important pour les propriétés de sélectivité et, d'autre part, les acides humiques ne peuvent pas être considérés en équilibre avec les acides fulviques.
On the occurrence of Alstonite and Ullmannite (a species new to Britain) in a Barytes-Witherite vein at the New Brancepeth Colliery near Durham
Authors: Spencer L. J.
Published: December 2006

The mining village of New Brancepeth, in the parish of Brandon and Byshottles, is situated in the Durham coalfield at a distance of four miles to the west of the city of Durham. One of the faults which intersect the sandstones, shales, and coal-seams (the Harvey, Busty, and Brockwell seams) of the Coal Measures at this place has, at its eastern end, an east to west direction with a downthrow of 120 feet and a hade of 20° to the south. Along this portion of its course the fault is of the nature of a fissure-vein, with a width varying from a few inches to 16 feet. The material filling the vein consists mainly of barytes. In places, especially where the walls of the vein are of sandstone, the pure white, massive barytes extends throughout from one sharply-defined cheek to the other.
An improved form of petrological microscope: with some general notes on the illumination of microscopic objects
Authors: Grabham G. W.
Published: December 2006

It is more than twenty-one years since Mr. Allan B. Dick communicated a description of the microscope, now generally associated with his name, to this Society. The instrument is familiar to all mineralogists, and it will suffice to say that the main feature consisted in having the polarizing and analysing prisms arranged so that they can be rotated simultaneously, instead of turning the object on the stage between them. The rotating stage is never very satisfactory, especially when it is desired to examine minute crystals in convergent light. In two pamphlets, published later, Mr. Dick extended his description of the instrument and gave some methods of using it.
A new siderolite from Bencubbin, Western Australia.
Authors: Simpson Edward S. , Murray D. G.
Published: December 2006

In July 1930 a fragment of this meteorite was received at the Government Laboratory, Perth, with a request from the sender that he should be informed of its nature and value. Realizing its scientific interest, one of the authors (E. S. S.) took advantage of a visit to Beneubbin (lat. 30° 48′ S., long. 117° 51′ E. ; about 150 miles NE. of Perth in the South-West Division) to interview the finder and suggest that the whole mass should be handed over to the Government Laboratory for examination, a specimen detached for the British Museum, and the main mass finally presented to the Western Australian Museum in Perth. This arrangement was agreed to.
The form relations of the lead oxychlorides, laurionite, paralaurionite, and fiedlerite
Authors: Palache Charles
Published: December 2006

The published data on these three minerals, first found in the Laurion lead slags, is well summarized in Hintze (Handb. Min., 1915, vol. 1, pp. 2632-2641). In studying the original papers for the purpose of recalculating the elements of each, LaForge was impressed with their close crystallographic relationship in certain respects and with the curious complexity of the form series of fledlerite, which seemed to call for further observations. Accordingly, crystals of all three minerals from Laurion were studied on the goniometer, specimens loaned by the U.S. National Museum furnishing a welcome supplement to those found in the Harvard Mineralogical Museum. In the following pages the results of these studies will first be presented in brief form. Following this, the conclusion arrived at as to the most appropriate positions of the three minerals to bring out their mutual relationships will be stated.
Aluminium replacing silicon in some silicate lattices
Authors: Harry W. T.
Published: December 2006

The purpose of this account is to review, from the literature, figures for the replacement of silicon by aluminium in biotites, calciferous amphiboles, and clinopyroxenes. Atomic ratios to be quoted have been calculated on a basis of 24(O,OH,F) in biotites, hornblendes, and pyroxenes alike. This facilitates comparison and the higher factor magnifies differences. It may be emphasized, to avoid possible confusion, that in this discussion it is the amount of silicon replaced by aluminium that will be under review. The ratio of tetrahedrally co-ordinated Al to octahedrally co-ordinated A1 will not be considered, although for the sake of completeness, figures for AI in Y groups will be furnished to show total A1 values. Machatschki's group notation is employed. Comparison between biotites, hornblendes, and clinopyroxenes, for present purposes, may best be made between minerals that crystallized under the same pressure-temperature conditions, to reduce variables. Few analyses of specimens of these three minerals, that have crystallized together in the same rock, are available however. One such paragenesis is quoted below. This association occurs as gneiss-like inclusions in calcite, taken from the Tiree marble.
The use of diamond-impregnated tools for rock-slicing
Authors: Dunham K. C. , Taylor J. T.
Published: December 2006

For the cutting of chips from rocks preparatory to thin-slicing, it has been standard practice for many years to use notched soft iron disks, manually armed with diamond powder. The latest machines employing cutting-disks of this type at the Geological Museum were built at the Government Training Centre, Ascot Works, Letchworth, to the design of the late Dr. H. H. Thomas and of Mr. W. Ward of the Centre. These are powered with 0.25 horse-power variable speed direct current motors, giving a maximum disk speed of 280 revolutions per minute. By means of rheostats, control of speed as sensitive as that obtainable with a treadle type of machine (see A. V. Weatherhead) is achieved. The normal speed for cutting is 160 to 180 r.p.m. In cutting a hard rock such as chert, it may be necessary to recharge the disk with diamond several times during the operation. The rock-specimen is held in a steel clamp with hardwood liners, mounted on a swinging arm. The rock is held in contact with the disk by the tension of a spring, or, during delicate work, by the pressure of the hand.
Nouvel essai de classification des chlorites
Authors: Orcel J. , Caillère Mlle S. , Hénin S.
Published: December 2006

Les chlorites peuvent être définis d'après G. Tschermak (I), puis t A. Lacroix (2), comme des silicates hydratés d' Al, de Mg, et de Fe, de couleur généralement verte, possédant un elivage facile suivant (001), les lames de clivages étant flexibles, sans être élastiques, comme celles du mica. Dans un travail antérieur, l'un de nous (3) avait tenté d'établir une classification de ces minéraux, en se basant directement sat les données de l'analyse chimique, sans faire intervenir d'idée théorique sur leur constitution, comme l'avait fait G. Tschermak et d'autres auteurs aprés lui. Peu de temps après, un certain nombre de recherches, effectuées à l'aide de rayons X, ont permis d'élucider les caractéres essentiels de la structure de ces phyllites. On peut done raisonnablement en tenter une nouvelle classification chimique tenant compte du schéma structural établi actuellement. C'cst ce que nous nous proposons de faire dans ce mémoire, aprés avoir exposé quelques remarques sur des travaux récents.
Studies of mineral sulpho-salts: XV. Xanthoconite and pyrostilpnite
Authors: Peacock M. A.
Published: December 2006

In his long conduct of the Mineralogical Magazine and Mineralogical Abstracts our Editor has always shown a ready interest and understanding for each new phase of mineralogy as it has appeared, and thus a contribution to any part of the wider realm of mineralogy would fall in the range of Dr. Spencer's comprehending appraisal. At the same time Dr. Spencer's own published work in mineralogy and the style of his abstracts of the works of others show that his personal interests incline to the classical natural history aspect of mineralogy, which gives first importance to exact observations that establish the individuality of new species, improve and extend the knowledge of well-defined species, or disprove the existence of supposed new minerals.
The petrology of the evaporites of the Eskdale no. 2 boring, east Yorkshire Part II. The middle evaporite bed (With Plates IX and X)
Authors: Stewart F. H.
Published: December 2006

The D'Arcy Exploration Company's boring, put down in 1938-39 near Aislaby, Eskdale, passed through three Permian evaporite beds. A petrological account of the rocks of the lower evaporite bed has been given in an earlier communication (Stewart, 1949). The present paper deals with the petrography of the middle evaporite bed.
Sedimentary inclusions in the hypersthene-gabbro, Ardnamurchan, Argyllshire
Authors: Wells M. K.
Published: December 2006

The hypersthene-gabbro of Ardnamurchan Point is the earliest of the intrusions of Centre 2 of the Ardnamurchan complex as shown by 5. E. Richey (11, p. 208).I The mass is intruded into domed Jurassic sediments and Tertiary basalt flows (fig. 1). The main part of the intrusion is composed of rather fine-grained gabbro, containing 2-3 % of hypersthene which typically surrounds crystals of olivine. Marginally, however, the gabbro is a quartz-bearing variety, with a micrographic mesostasis. The outer contact is somewhat sinuous due to the fact that the intrusion has only been exposed to a comparatively small depth below its original roof. This same geological accident may account in part for the number of fine-grained, basic, granular masses that are locally abundant within the gabbro.
Cataclastic pegmatites and calc-silicate skarns near Bunbeg, Co. Donegal
Authors: Whitten E. H. T.
Published: December 2006

In this paper is described a series of three small pcgmatite dikes and the skarns produced by them in Dalradiau ealc-silicate hornfelses, and after full discussion certain conclusions are deduced as to the mode of origin of these rocks. This suite has not been described previously and lies to the south of Bunbeg quay and to the east of Loughlin island (fig. 1). Tim only published accounts of the area contain but passing reference to some of the features here described. In 1891 Nolan (1) merely noted the existence of 'remarkable beds of garnetiferous limestone withtremolite' near the small village of Bunbeg, whilst Zealley (2) in 1909 briefly referred to these hornfelses.
The characterization of serpentine minerals by X-ray diffraction
Authors: Whittaker E. J. W. , Zussman J.
Published: December 2006

X-ray diffraction data on serpentine minerals are discussed. There arc three structural varieties of chrysotile: ortho-chrysotile, clino-chrysotile, and para-chrysotile. Methods are described for the estimation of the proportions of the first two of these in mixed specimens, and their distribution in nature is reviewed. The variations observed in powder photographs of serpentine minerals are interpreted in accordance with this classification. The criteria proposed by Selfridge for distinguishing between chrysotile and antigorite are shown to be unreliable, but valid criteria are presented. The powder photographs also reveal the existence of a third serpentine mineral, distinct from chrysotile and antigorite, for which the name lizardite is proposed. Four samples of bastite are shown to consist of chrysotile or lizardite rather than antigorite. All the serpentine minerals examined consist either of antigorite or of one or more of the group comprising lizardite and the chrysotile varieties.
Heating experiments on amazonite
Authors: Oftedal Ivar
Published: December 2006

The rate of decolorization of a Norwegian amazonite was studied at various temperatures: near 500° C. it was almost instantaneous, becoming successively slower with lower temperatures, until at 300° C. no change was visible in 10 hours. It is concluded that the colour is stable indefinitely below about 270° C. and that this is the maximum temperature at which the colour could have appeared.
Painite, a new mineral from Mogok, Burma
Authors: Claringbull G. F. , Hey Max H. , Payne C. J.
Published: December 2006

A singly terminated transparent, deep-garnet-red crystal originally weighing 1·7g. from a gem gravel from Mogok, Burma, proves to be a new mineral having Al2O3 76·2, SiO2 5·6, B2O3 2·2, CaO 15·7, H2O 0·7, Fe2O3 and MnO traces, total 100·4. Sp. gr. 4·01; ω 1·8159, ɛ 1·7875; H 8. The hexagonal unit cell has a 8·725, c 8·46 Å., space group P63, P63/m or P63 22, and contains approximately 38 O. The name painite is proposed in honour of A. C. D. Pain who recognized the unusual nature of the crystal.
The paragenesis of garnet in charnockite, enderbite, and related granulites
Authors: Howie R. A. , Subramaniam A. P.
Published: December 2006

The presence of garnet in acid rocks of the charnockite series south of Madras is reported. Petrographic deseriptions of garnetiferous enderbites and related pyroxene-granulites, khondalites, and leptynites are accompanied by new chemical analyses of 6 rocks, 8 garnets, and 5 orthopyroxenes from the type area near Madras, and from Ceylon, Varberg, and Uganda. The garnets show a considerably higher FeO/MgO ratio than the coexisting ortbopyroxenes and the host rocks. The presence or absence of garnet appears to be related to the bulk chemistry of the rocks. Basic garnetiferous granulites associated with these rocks are considered to represent an unstable mineral assemblage and may be genetically unrelated to the acid types. Attention is drawn to the prevalence of enderbitic rocks in the type area.
Heating experiments on some natural titaniferous magnetites
Authors: Vincent E. A. , Wright J. B. , Chevallier R. , Mathieu Suzanne
Published: December 2006

Chemically analysed samples of magnetites carrying exsolved ulvöspinel and ilmenite have been heated in vacuo at various temperatures without change in overall chemical composition and the changes occurring studied microscopically, magnetically, and by X-rays.

Magnetite with exsolution bodies of ulvöncl can be homogenized probably below 600°C.; thermomagnetic curves and microscopic textures suggest that the solvus curve is very steep at the Fe3O4 end of the Fe3O4-Fe2TiO4 series.

On heating magnetite containing ilmenite lamellae up to 950°C., some interchange of ions between the phases occurs (Fe3O4+FeTiO3 → Fe2TiO4+Fe2O3, the ilmenite lamellae taking Fe2O3 into solid solution. The accompanying host magnetite not only gains Fe2TiO4, but at the same time dissolves some FeTiO3. Above 950°C. extensive decomposition takes place, with the production of pseudobrookite, and homogenization has not been achieved. It is suggested that under magmatic conditions extensive solid solution exists in which the FeTiO3 component may be regarded as having a spinel (γ) structure; after exsolution, monotropic inversion may occur to yield a rhombohedral ferri-ilmenite (Chevallier et al., 1955), which on slow cooling changes in composition towards FeTiO3.

Magnetite with exsolution bodies of both ulvöspinel and il menite shows on heating the features of both the above binary types.
New data for dumortierite
Authors: Claringbull G. F. , Hey M. H.
Published: December 2006

New chemical, optical, and X-ray data have been obtained for dumortierite. The unit cell. space group Pemn, contains 4[(Al,Fe)7BSi3O18]. Brown gem quality material from Ceylon has α 1·6860, black, [001], β 1·722, deep redbrown, and γ, 1·7229, brown, with 2Vα 13° , γ > υ. X-ray powder data are given.
Delhayelite, a new silicate from the Belgian Congo
Authors: Sahama TH. G. , Hytönen Kai
Published: December 2006

The complex kalsilite-bearing melilite-nephelinite from Mt. Shaheru in the Belgian Congo with götzenite, combeite, and kirschsteinite contains yet another new silicate for which the name delhayelite is proposed.

Delhayelite is orthorhombic with a 6·53, b 24·65, c 7·04 Å. Possible space-groups Pmn21 and Pmmn. Weak super-cell with doubled a-axis. Distinct cleavage parallel to (010). Birefringence weak. α ≈ β ≈ γ = 1·532. 2Vα = 83°. Optical orientation: a = α, b = γ, c = β. Sp. gr. 2·60. Chemical composition corresponds to the tentative formula (Na,K)4Ca5Al6Si32O80.18H2O.3(Na2,K2)(Cl2,F2,SO4).
Some further heating experiments on natural titaniferous magnetites (With Plate III.)
Authors: Wright J. B.
Published: December 2006

Samples of magnetite containing exsolution bodies of ilmenite, or of ulvöspinel and ilmenite, were heated at 1,250–1,300° C. under oxidizing and under reducing conditions.

In the former case, the product consisted of magnetite, ferri-ilmenite, and pseudobrookite. In the latter, loss of oxygen converted a magnetite-ilmenite intergrowth into a homogeneous Fe3O4-Fe2TiO4 spinel solid solution, while a magnetite sample originally carrying ulvöspinel in addition to ilmenite yielded a spinel phase with surprisingly low cell dimension, together with some metallic iron.
Stevensite from the Whin Sill in the Region of the North Tyne
Authors: Randall B. A. O.
Published: December 2006

A stevensite occurring as an alteration product of pectolite in amygdale-like structures within the Whin Sill is described. Data given for the stevensite include optical properties, stain reactions, chemical analysis, X-ray powder data, and D.T.A. curves. The close similarity between many of the properties of sepielite and stevensite is indicated and D.T.A. is shown to be the most satisfactory method of distinguishing between the two minerals.
An X-ray study of manganese minerals
Authors: Mukherjee Bibhuti
Published: December 2006

Rhodonite, rhodochrosite, spandite, psilomelane, beldongrite, braunite, sitaparite, and vredenburgite from a collection hy Fermor have been studied by the X-ray powder diffraction method. The cell dimensions of all forms of eryptomelane—massive, horny, botryoidal, reniform, mamillated, and stalactitic—are a = 9.82 Å., c= 2.86 Å.. whereas the cell dimensions of shiny pitch-like beldongrite are a= 9.82 Å., c= 2·87 Å. The amorphous admixture associated with cryptomelane is revealed by a broad halo, 4·60 Å. to 3·90 Å., in the powder pattern. Aminoff's crystal data for braunite are discussed with a different orientation, and a new space group, I 4/mmm, is assigned after indexing the powder pattern. Fermor' sitaparite (bixbyite) is assigned a new space group Im3 , different from that proposed by Pauling et al., on the basis of a fresh indexing of the powder pattern. Manganese-garnet from the gondite series has a cell-size of the order of spessartine, whereas the cell-size of manganese-garnet from the kodurite series varies from 11·72 to 11·95 Å. Fermor's spandite from the kodurite series is a mixture of spessartine, grossular, and andradite garnet-molecules with almandine and pyrope as minor components. Ramsdellite and γ-MnO2 or β-MnO2 are found in a number of samples of manganese ores.
Nepheline solid solutions
Authors: Donnay Gabrielle , Schairer J. F. , Donnay J. D. H.
Published: December 2006

Published chemical analyses demonstrate that the nepheline formula should be written KxNayCaz□s-(x+y+z)Alx+y+2zSi16-(x+y+2z)O32, where □ stands for vacant sites. X-ray data are presented for the nepheline phase in four binary systems: Ne-CaAl2O4, Ne-An, Ne-Ab, Ne-Kp. Only in two of these systems do the cell-dimensions change with composition. In the first one, the cell-volume V increases linearly with increasing calcium content; in the last one, two singularities in the curve of V against x divide the phase Na8-xKxAl8Si8O32 into three subphases: subpotassic (0 < x < 0·25), mediopotassic (0·25 < x < 2·00), and perpotassic (2·00 < x < 4·73). Only in the subpotassic range are both high- and low-temperature forms found. Twenty-eight natural nephelines, for which chemical analyses and X-ray data are available in the literature, show that only the potassium content affects cell-dimensions. Although all analysed natural nephelines fall outside the subpotassic range, the re-examination of a Monte Somma specimen studied by Bannister (1931) reveals a few euhedral crystals of subpotassic nepheline in a mediopotassic phase.
The kinetics of the ordering process in triclinic NaAlSi3O8
Authors: McConnell J. D. C. , McKie Duncan
Published: December 2006

A kinetic analysis is presented of the data of MacKenzie (1957) on the hydrothermal treatment of NaAlSi3O8 under isobaric, isothermal conditions in the temperature range 450° C. to 1000° C.

The analysis indicates the existence of a smeared polymorphic transformation in the temperature range around 600° C. The activation energy for the transformation is about 60 kcal. mole−1 and has been equated with the process of self-diffusion involved in Al-Si ordering in the structure. Some dry-heating experiments and the influence of varying water vapour pressure are discussed.
The amygdale minerals in the Tertiary lavas of Ireland. III. Regional distribution
Authors: Walker G. P. L.
Published: December 2006

Zeolites occur at most of the 670 localities studied in the Antrim Basalts, and the ten most abundant species, in order of frequency, are chabazite, thomsonite, analcime, levyne, natrolite, mesolite, stilbite, gmelinite, heulandite, and phillipsite. Gismondine, laumontite, and mordenite are recorded for the first time. Chabazite and thomsonite characterize the upper parts of the lava succession. Below, they are joined by analcime and natrolite and, in some areas where zeolitization is most intense, by stilbite and heulandite, as well. These mineral zones have been mapped, and they probably reflect the temperature distribution in the lavas during zeolitization. Being discordant and clearly superimposed upon the lavas, these zones establish the late age of zeolitization in the volcanic history of Antrim. In places the zeolite zones are missing, and in their place a mineral assemblage rich in calcite, aragonite, quartz, and chalcedony is found. The tholeiite lavas that occupy a small area in north Antrim have an amygdale mineral assemblage different from that in the olivine-basalts, which constitute the remainder of the lava outcrop.
Kennedyite, a new mineral of the pseudobrookite series
Authors: von Knorring O. , Cox K. G.
Published: December 2006

A new mineral with the approximate composition of Fe2MgTi3O10 and isostructural with pseudobrookite Fe4Ti2O10 has been observed in an olivine-augite-alkali-feldspar rock of the Karroo succession from the Mateke Hills area in south-eastern Southern Rhodesia. Chemical analysis and indexed X-ray powder data (α 9·77, b 9·95, c 3·73 Å.) of the mineral are given, and the name kennedyite is proposed. The name karrooite is proposed for the artificial product MgTi2O5.
Petrology of the Scourie dyke, Sutherland (Plate XVIII)
Authors: O'Hara M. J.
Published: December 2006

Chemical data are given for four rocks from the Scourie dyke, Sutherland, and for the constituent minerals. Three of the specimens are unsheared and represent stages in a continuous variation from a one-pyroxene (subcalcic ferroaugite) dolerits through partially amphibolized two-pyroxene dolerite to garnet-plagioclase amphibolite. These changes are not accompanied by conspicuous changes in bulk composition. The garnetiferous varieties represent a border facies of the dyke, which is in contact with little-altered pyroxene-bearing gneisses of the Lewisian complex. The fourth specimen is a hornblende schist formed from the dolerite by shearing. This change also involves little change in bulk composition, and affects impartially the three types of dolerite referred to above. Mineral relations are discussed and a hypothesis advanced to account for the garnetiferous border facies of the intrusion, invoking intrusion while the country rock was at relatively high temperature and pressure.