Search

Copper indium gallium diselenide (CIGS) based technology is actively competing in the global photovoltaic market with high conversion efficiency. Commercial CIGS modules are anticipated to perform on rated output in the field condition for 20 years. Potential induced degradation (PID) is considered as one of the critical concerns among all the current reliability assessment issues. PID accelerated tests have been performed on pre‐commercial CIGS modules to investigate reduction in electrical performance. We report the severe reduction in electrical performance after PID is correlated to the microstructural and chemical properties of the constituent materials. Under extreme PID stress, the cell surface reveals various defects including crater formation. The aim of this article is to explore the consequences of PID induced craters on the efficiency of CIGS solar cells by investigating material degradation kinetics. In this perspective, we present the root cause of PID in CIGS thin‐film modules in relation to microstructural defects by detailed investigation using J‐V analysis, field emission scanning electron microscope (FESEM), Raman spectroscopy, X‐Ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy (PL). This analysis can provide more effective and sustainable research strategies to cultivate more efficient and reliable CIGS technologies in the long run.

Sustainable materials like paperboard can substitute for crude oil‐based polymers in packaging applications and, by doing that, reduce the negative environmental impacts caused by plastic waste. For a broader application in the packaging industry, the forming of paperboard needs to overcome its limited forming behaviour and barrier properties. The presented work aims to influence the forming behaviour of uncoated and polyethylene terephthalate (PET)‐coated paperboard with additives like water, gelatin and soap. Furthermore, the differences in the mechanical behaviour of coated and uncoated materials are investigated. For the studies, tensile, bulge and forming tests were combined with different optical measurement methods. The investigations showed that the overall forming behaviour is affected by the mentioned additives and can be improved. Additionally, the interaction of the coating and substrate paper is investigated under different load conditions. Post-print / Final draft

Heritage conservation science is a valuable technique for improving understanding and the preservation of historical objects. Material analysis of heritage textiles and related materials provides information about polymer and colorant degradation, and contributes to improved conservation and display practices. The re‐creation of materials following historical processes is useful for testing analytical techniques in a field where ethical constraints often limit sampling, and to also identify potential age‐related changes relative to a fresh product. Despite the broad historical interest and industrial significance of Turkey red from the late eighteenth to the nineteenth century, little about the chemical complex of these unique textiles was understood in scientific terms. This study applied modern analysis with 1H and 13C nuclear magnetic resonance (NMR) spectroscopy to investigate the conclusions reached by nineteenth century chemists, that fatty acids were a key component of the oil treatment, a unique and vital aspect of the Turkey red dyeing process. The results show that Turkey red oil samples are composed of fatty acids which tend to polymerise over time, and that modern commercial Turkey red oil has a similar composition to historical samples and a replica sample made following a nineteenth century method. This information was used to form a hypothesis for the overall Turkey red complex on the fibre, and confirmed that the experimental work of nineteenth century chemists was theoretically accurate despite their lack of precise analytical techniques. This indicates that a re‐creation and analysis approach is effective for studying heritage materials, provided the historical practice for making the original object is taken into consideration.

All-inorganic CsPbI3 holds promise for efficient tandem solar cells, but reported fabrication techniques are not transferrable to scalable manufacturing methods. Herein, printable CsPbI3 solar cells are reported, in which the charge transporting layers and photoactive layer are deposited by fast blade-coating at a low temperature (≤100 °C) in ambient conditions. High-quality CsPbI3 films are grown via introducing a low concentration of the multifunctional molecular additive Zn(C6 F5 )2 , which reconciles the conflict between air-flow-assisted fast drying and low-quality film including energy misalignment and trap formation. Material analysis reveals a preferential accumulation of the additive close to the perovskite/SnO2 interface and strong chemisorption on the perovskite surface, which leads to the formation of energy gradients and suppressed trap formation within the perovskite film, as well as a 150 meV improvement of the energetic alignment at the perovskite/SnO2 interface. The combined benefits translate into significant enhancement of the power conversion efficiency to 19% for printable solar cells. The devices without encapsulation degrade only by ≈2% after 700 h in air conditions.

In order to achieve higher utilisation rates for the material excavated from underground construction sites, one of the main objectives is efficient, digital processing of available data on material, mass and time parameters for the mined rock. Selected information needs to be made available to a wide audience at the same time. This initiates a value chain, which goes far beyond the construction industry and enables successful upcycling. The evolving software MineralBay is committed to this goal by using the internet to bring together owners or suppliers of mineral resources with customers easily, quickly and at any time to facilitate the exchange and trading of raw materials. MineralBay is a management and merchandising system for excavated material, whose speciality is access to and processing of real-time data, e.g. in the form of online material analysis results from tunnel boring machines. The information obtained is used for quality management of already placed excavation material and for gapless documentation of the material flow from the beginning to the end of the construction project. Eines der Kernziele zum Erreichen hoherer Verwertungsquoten von Ausbruchmaterial bei untertagigen Bauprozessen ist die effiziente digitale Aufbereitung vorhandener Daten zu Material-, Massen- und Zeitparametern des Tunnelausbruchs, wobei zugleich ausgewahlte Informationen einem breiten Interessentenkreis zuganglich sein sollen. Dadurch wird eine Wertschopfungskette initialisiert, die weit uber die Baubranche hinausgeht und so ein erfolgreiches Upcycling ermoglicht. Diesem Ziel soll die in Entwicklung befindliche Software MineralBay dienen, die Besitzer, Lieferanten und Bedarfstrager mineralischer Rohstoffe einfach, schnell und zu jeder Zeit uber das Internet zusammenfuhren kann, um so den Austausch und Handel von Rohmaterialien zu vereinfachen. MineralBay ist ein Ausbruchmaterialverwaltungs- und -vermarktungssystem, dessen Besonderheit die Anbindung an Echtzeit-Datenanalysen ist, z.B. in Form einer Online-Materialanalyse auf der Tunnelbohrmaschine. Die dadurch gewonnenen Informationen dienen dem Qualitatsmanagement des vermittelten Ausbruchmaterials und der luckenlosen Dokumentation des Materialstroms vom Beginn bis zum Ende des Bauprojekts.

Latin American movements have been on the forefront of proposing alternatives to neoliberalism throughout the past decades. Bolivia and Ecuador stand out, because both countries have passed constitutional reforms that established plurinational states. In Bolivia, the historically marginalized indigenous and peasant populations have demanded nothing less than a refoundation of the country. Beginning in the 1990s and intensifying since 2000, they have set a new political agenda for that purpose, focusing fundamentally on resource appropriation and the plurinational state project, but the extent of politico–economic transformations is not clear. Some highlight them as part of the only important counter-hegemonic processes at the state level, and others stress the existence of “path-dependencies,” point to the continuities between the politics of the Movement for Socialism and that of its neoliberal predecessors, or even classify these as autocratic attempts at power grabbing. In this article, I choose a new approach. Based on a strategic–relational understanding of the state, I will examine state power by two means of the state, law and money. First, I analyze negotiations over the constitutional process, and then I examine budgetary politics from 2001 to 2011. This period includes the height of social mobilizations, and it was during this time that the state transformation project began. I use this approach to argue that renewed state power, and specifically a new political power correlation, became visible during the constitutional process and subsequently through state finances. This material analysis will reveal the new political power correlation and emerging state power, and also provide more clarity about ongoing political and economic transformations. Los movimientos latinoamericanos han estado al frente para proponer alternativas al neoliberalismo en las ultimas decadas. Destacan Bolivia y Ecuador, ya que ambos paises han aprobado reformas constitucionales que establecieron estados plurinacionales. En Bolivia, las poblaciones indigenas y campesinas que siempre han estado marginalizadas han exigido nada menos que una refundacion del pais. A partir de la decada de 1990 y con mayor intensidad desde 2000, han fijado una agenda politica para tal proposito, enfocandose primordialmente en la apropiacion de los recursos y en el proyecto estatal plurinacional, aunque no esta clara la magnitud de la transformacion politica-economica. Algunos autores los destacan como parte de los unicos procesos contrahegemonicos importantes a nivel estatal, mientras que otros enfatizan la existencia de “sistemas de dependencia”, resaltando las continuidades entre las politicas del MAS y las de sus predecesores neoliberales, o hasta los clasifican como intentos autocraticos de apropiarse el poder. En este articulo, adopto un enfoque diferente. Basado en una aproximacion estrategica-relacional del estado, examino el poder estatal por medio de la ley y el dinero. Primero, analizo las negociaciones respecto al proceso constitucional, y despues examino la politica presupuestaria de 2001 a 2011. Este periodo incluye el auge de las movilizaciones sociales, y fue en esta epoca que el proyecto estatal comenzo. Uso este acercamiento para argumentar que el poder estatal renovado, especificamente una nueva correlacion del poder politico, se hizo visible durante el proceso constitucional y por lo tanto por las finanzas del estado. Este analisis material revela la nueva correlacion de poder politico y la emergencia del poder estatal y tambien proporciona mas claridad sobre las continuas transformaciones politicas y economicas.

Research from the past year demonstrates archaeologists’ diverse contributions to the anthropological study of human experience and social relationships in time and space. I divide literature published from late 2013 to late 2014 into five themes. First, archaeological research on space focuses on the persistence and materiality of landscapes, the creation and dynamics of communities and cities, and the mobility and migration of people. Second, studies of climate change and environmental interaction stress that organizational relationships and their long-term legacies are fundamental to ecological sustainability. Third, archaeologists offer anthropology the ability to contextualize the causes and the manifestations of violence and conflict through longitudinal cases studies and material analysis. Fourth, work on objects, bodies, and identity emphasizes that social subjectivities are not only variable but are historically connected to material worlds. Finally, fifth, archaeologists engaged with the present offer critical understandings of heritage policies and promote an activism that seeks more ethical practices with descendent communities and within the discipline itself. Despite differences, the recent literature reveals archaeologists’ contributions to these significant anthropological topics by studying long-term, historical legacies and the materiality of human relationships. [archaeology, anthropology, materiality, history, year in review]

Considering the increasing shortage of resources, the reuse of material excavated from tunnels is the order of the day, which is being followed by clients, consultants and contractors as well as lawmakers. In addition to the creation of a legal situation to enable efficient and unbureaucratic reuse, further technical developments are also required in relation to material analysis to enable an immediate characterisation of the material at the face according to the decisive parameters for reuse. The linking of these results with a raw material database, in which the results of the material analyses are stored, represents a step towards modern, web-based handling of mineral raw materials. Die Wiederverwertung von Tunnelausbruchmaterial ist in Anbetracht zunehmender Rohstoffverknappung ein Gebot der Stunde, das es sowohl von Auftraggebern, Planern und Baufirmen als auch dem Gesetzgeber selbst zu verfolgen gilt. Neben der Schaffung einer rechtlichen Situation, die eine effiziente und unburokratische Verwertung ermoglicht, sind auch technische Weiterentwicklungen in Bezug auf eine Materialanalyse gefordert, die eine Charakterisierung des Ausbruchmaterials sofort am Anfallort nach den fur eine Verwertung entscheidenden Parametern ermoglicht. Die Verknupfung dieser Resultate mit einer Rohmaterialdatenbank, die mit den Ergebnissen der Materialanalyse gespeist wird, stellt den Schritt zu einem modernen, webbasierten Handel mit mineralischen Rohstoffen dar.

Durch die Entwicklung von Staub im Zuge der schneidenden Gewinnung von Steinkohle kann eine gesundheitsgefahrdende Atmosphare entstehen. Mit sinkender Korngrose des Staubs lasst sich dieser einatmen und das Risiko, an einer Pneumokoniose zu erkranken, steigt. Durch die staubhaltige Atmosphare verstarkt sich das Risiko von Staubexplosionen im Zusammenhang mit Grubengasexplosionen deutlich. Im Gewinnungsbetrieb flozartiger Lagerstatten ist die Staubentwicklung von zahlreichen Betriebs- und Maschinenparametern beeinflusst. Hierzu zahlen unter anderem der Ruckvorgang des Schildausbaus, die Forderergeschwindigkeiten – insbesondere an den Ubergabestellen –, die Parameter der eingesetzten Brecher sowie die Wettergeschwindigkeit. Ein Grosteil des Staubs entsteht beim Loseprozess des hereinzugewinnenden Materials durch den Walzenlader. Dieser Prozess ist wiederum von zahlreichen Parametern wie den eingesetzten Werkzeugen, Schnittgeschwindigkeiten und Schnitttiefen abhangig. Die Freisetzung von Staub lasst sich in Gewinnungsbetrieben nicht vollstandig vermeiden, sondern durch geeignete Verfahren (z.B. Bedusung des hereingewonnenen Materials) bestenfalls vermindern. Dieses zwangsweise freigesetzte “Gefahrgut” kann jedoch fur eine Materialanalyse genutzt werden, um beispielsweise Kohle von Nebengestein bereits wahrend des Schneidprozesses zu unterscheiden. Auf Basis dieser Informationen kann der Walzenlader automatisiert gesteuert werden, sodass die Anwesenheit eines Maschinenbedieners in der Gefahrenzone nicht mehr zwingend erforderlich ist. Utilizing of dust in longwalls with cutting operation Dust generation during hard coal extraction by cutting strongly affects the health of humans. With decreasing particle size, the risk of inhaling the dust increases and, therefore, the risk of inflicting pneumoconiosis rises. Additionally, the presence of dust increases the hazard of dust explosions which can result in a high degree of damage when combined with firedamp explosions. During the extraction of hard coal by shearer loaders, numerous factors affecting dust generation are present. These factors can affect each other and are generated by movement of the shields, AFC and feeder breakers as well as mine ventilation. The major amount of the dust, however, is generated by the shearer loader itself, influenced by, for instance, pick geometry, pick material and wear as well as the gap space between intersection lines. The release of dust during cutting cannot be avoided, but is limited by numerous measures, including venturi sprays on the drum. For automating the extraction of hard coal, however, the released dust during cutting can be utilized for material analysis of the extracted material. This has the advantage of utilizing a potentially dangerous medium and, additionally, of reducing the present amount of dust in the atmosphere and minimizing health and safety risks for machine operators.

Der Beitrag thematisiert Werkstoffuntersuchungen an historischen Lagern aus Stahlguss. Nach Erlauterungen zum Kontext der Arbeiten werden die Untersuchungsmasse vorgestellt sowie zwei unterschiedlich ausgerichtete Untersuchungsschleifen erlautert. Gegenstand beider Schleifen bilden chemische, mechanische und metallographische Werkstoffanalysen, deren Ergebnisse abschliesend gewertet werden. Material tests at historic bearings made of cast steel. This paper tackles material tests carried out at historic bearings made of cast steel. At first the context of the tests as well as the bearings which have been analysed are introduced. To improve our knowledge about historic cast steel this contribution explains two test series to investigate chemical, mechanical and metallographic material characteristics of historic cast steel. The paper ends with a conclusion.

Defects may arise in the semiconductor substrate and at interfaces due to the processing used to fabricate transistors and circuits. The development of low-thermal-budget processes, which is advantageous in many ways, unfortunately reduces the likelihood of annealing out these electrically active defects. Electrical characterisation using simple diode structures yields valuable information; not only the absolute leakage current density value, but also carrier lifetimes, leakage activation energies, and diode ideality factor. Coupled with material analysis techniques, they can provide a detailed picture of the problems associated with process-induced defects, and supply insight that can target optimised processes. In this paper the technological relevance of electrically active defects, their impact on device performance and power supplies, as well as their electrical and material characterisation, will be discussed. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

X-ray fluorescence (XRF) analysis is one of the most widely used techniques for material analysis in the field of cultural heritage, thanks to its non-destructive and multi-elemental character and also to the possibility of using portable instrumentations. The need of compact systems for in situ analyses results generally in a worse, more limited performance: the detection of low-Z elements is the most affected aspect. In this article, we present a custom-realised portable XRF spectrometer developed in Florence at the LABEC laboratory of Istituto Nazionale di Fisica Nucleare (INFN), in collaboration with ICVBC of Consiglio Nazionale delle Ricerche (CNR). The system features a high efficiency for a wide range of elements, even at low Z (down to sodium), thanks to the use of two tubes with different anodes and to the presence of a continuous helium flow in front of the tubes and the detector, in order to enhance transmission of both primary and characteristic X-rays. After a detailed description of the spectrometer, the experimental characterisation of its performance is presented: efficiency curves obtained from the analysis of thin standards are reported, together with minimum detection limits for some elements in a thick target of medium-low density matrix. Examples of measurements, which demonstrate the capability and effectiveness of this spectrometer, are also reported.

Objective To study the full panoramic view with figuring of the morphology and topography of the human tympanic annulus. Study Design Postmortem material analysis. Setting University-affiliated hospital. Subjects and Methods Twenty-three single, normal human adult tympanic membranes were completely extracted from formalin-fixed temporal bones. They were faced medially and placed at the same level of a graph paper mounted on a board. High-quality images of the tissue preparations were taken, and computer-aided measurements of the annular caliber were calculated at nine reference points. The 6 o'clock direction served as a midpoint, and another four reference points were set anteriorly and posteriorly in clockwise and counterclockwise directions. Results The annulus has a horseshoe-like shape with a small part absent above the neck of the malleus. The maximal mean caliber at the manubrial axis (6 o'clock direction) was 748 ± 201 μm. The annulus gradually thins out almost symmetrically anteriorly and posteriorly, until it reaches about 15 percent of the maximal caliber at its end points (152 ± 87 and 113 ± 42 μm, respectively). Significant differences were found between adjacent reference points on both anterior and posterior sides. Conclusions The annulus has a horseshoe-like shape and gradually thins out almost symmetrically, reaching anteriorly and posteriorly about 15 percent of the maximal caliber at the manubrial axis. These new data may provide guidance in transcanal middle ear exploration and suggest the possibility of varied functions attributable to the annulus regarding middle ear sound transmission and TM vibratory properties. The data may contribute to understanding the development of marginal perforations and posterior superior retraction pockets.

Zur Charakterisierung der ermudungsrelevanten Werkstoffveranderungen infolge hochfrequenter Schweisnahtnachbehandlung hat sich der Einsatz von mikromagnetischen Werkstoff- und Spannungsanalysen vorteilhaft gezeigt. Fur Standardbauteile hat sich gezeigt, dass die Qualitatssicherung der Nachbehandlung mit hoherfrequenten Hammerverfahren bei Einhaltung der Behandlungsparameter durch eine Sichtkontrolle moglich ist. Das Mikromagnetische Verfahren ermoglicht bei neuen Anwendungsfallen eine Gutekontrolle der Nachbehandlung an Arbeitsproben ·und am Realbauteil. A measurement technique for inspection of material subsurface changes after mechanical surface treatment. The micro-magnetic stress and material analysis has shown to be advantageous for characterizing the fatigue related material properties after high frequency post weld treatment. The quality control of standard parts treated by high frequency hammer peeing with the same peening parameters is possible by means of visual inspection. For new applications, the micro-magnetic analysis provides a quality control of post weld treated work samples and real components.

Bei modernen GD-OES-Geraten (GD-OES = Glow Discharge Optical Emission Spectrometry) wird die Analysenzeit (Bruttoanalysezeit: 2 - 5 Minuten) wesentlich durch die Abpumpzeit der Quelle und die Zuverlassigkeit der Spektralanalyse - besonders bei der Analyse dunner Schichten (Schichtdicken

This paper advances an extended material analysis to the study of technological change in a call centre. It shows how such an analysis is particularly apropos for understanding the distance that often separates managerial intentions in introducing a new technology from the outcomes associated with how workers utilise it.

Intrinsic and extrinsic defects are at the origin of photorefraction. Donor and acceptor defects define the properties of the photorefractive response in particular its dispersive behavior. This enables, e.g., targeted material design by incorporation of extrinsic defects in photorefractive media. Vice versa, defect physics benefits from photorefraction, i.e., photorefraction is successfully applied in defect studies and material analysis. Concepts for investigations make use of the great variety of nonlinear photorefractive phenomena. These include the appearance of a transient light-induced absorption, two-wave mixing at one-dimensional photonic gratings, photo-assisted self-assembly of photonic gratings and space-charge waves originating from oscillating photonic gratings.

Steel has continued to develop its status as a lightweight construction material for the design of vehicle bodies, most recently with the development of multi-phase steel. With a specific mixture of different phases in the steel microstructure, multi-phase steel combines high stability with good forming capacity. The characterisation of the complex structure of the multi-phase steel represents a challenge for metallurgists. For some years a new generation of X-ray diffractometers with two-dimensional (area) detectors and apparatus for local dissolved measurements are available to customers [5]. This paper reports the applications and advantages of the modern X-ray diffractometry method. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), and energy dispersive X-ray spectroscopy (EDS) in addition to scanning electron microscopy (SEM) have been used for determining the color and chemical composition of the architectural elements of the facades of a historical building, which today is the seat of the Diputacion Provincial of Cadiz. It dates from 1770 and was built as Custom Headquarters. It is near the port and is almost encircled by the walls of the city. The determination of the color and chemical composition of the materials that provoke this color and the determination of the layers found in the extracted samples from significant zones allow to define the various interventions over the facade and to localize the time in which they were made. This is possible by comparing with graphical registries and historical documentation. The objective is a study of the color of the different facades that the building has had in order to know the history of the building and to choose materials and colors that should be used in a restoration intervention of this historical building. © 2005 Wiley Periodicals, Inc. Col Res Appl, 30, 382–390, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.

Material analysis of Limoges painted enamels was undertaken by using an x-ray fluorescence spectrometer equipped with a low-power x-ray tube, polycapillary x-ray optics and a silicon drift chamber detector. The spectrometer, which includes helium purging for detecting elements down to sodium, can easily be assembled and dismantled within 1 h. A quantification method for enamel and glass objects was developed and verified using standard materials. The layer arrangement and possible influence on the XRF measurements were especially considered in theoretical calculations. Over 160 painted enamels from the late Renaissance and Revival periods in the 19th century in various collections were investigated. Comparison of the quantitative results from objects which are securely dated and attributed by art historians allowed a more reliable attribution of pieces with doubted authenticity. Copyright © 2004 John Wiley & Sons, Ltd.

The current and previous condition of solid waste management programs in the city, Shiraz was studied. Shiraz is one of the capital cities in south of Iran. Different aspects of solid waste programs including collection, transportation, treatments and recycling are discussed. Composition of solid wastes, material analysis, chemical formulation, thermal values, pH and other factors is evaluated. To estimate future conditions an overview of the statistics obtained in previous years is provided. Finally some recommendations are given in case it would be profitable for developing recycling programs in Shiraz city.

The reasons for the foundation of ECASIA lay far back in the late 50s and 60s of the last century, when material analysis was identical with bulk analysis. With the appearance of surface analytical techniques such as SIMS and AES, the importance of surface analysis became evident. Unfortunately, analysis at that time was considered as inferior to fundamental studies. The infrastructure of analytical laboratories, worldwide, was poor, compared with today's abundant facilities. To cope with all these difficulties, cooperation of all those involved in the application of surface techniques to practical problems was considered inevitable. This resulted in the establishment of the concept of ECASIA in 1982 followed by the first ECASIA conference in 1985. Copyright © 2010 John Wiley & Sons, Ltd.

The Manifold Method of Material Analysis (MM) with high-order displacement functions has been derived based on triangular meshes for the requirement of high accurate calculations from practical applications. The matrices of equilibrium equations for the second-order MM have been given in detail for program coding. The derivation of the method is made by means of approximation theory and very few new mathematical concepts are used in this paper. So, it may be understood by most engineering researchers. By close comparison with widely used Finite Element Method, the advantages of MM can be seen very clearly in the following aspects: (1) the capability of processing large deformation and handing discontinuities like block oriented Discontinuous Deformation Analysis method; (2) making element meshes easily and (3) using high-order displacement functions easily. The C program codes for the second-order MM has been developed, and it has been applied to the example of a beam bending under a central point loading. The calculated results are quite good in agreement with theoretical solutions. By contrast, the results calculated for the same model by use of the original first-order MM are far from the theoretical solutions. Therefore, it is important and necessary to develop high-order Manifold Method for the complicated deformation problems. © 1998 John Wiley & Sons, Ltd.

There are several cases where x-ray analyses of material cannot yield the desired results (e.g., if materials of nearly identical chemical composition are considered.) Spectral cathodoluminescence (CL) investigations can be used to overcome these difficulties. For this purpose, CL standard spectra of different standard substances are presented here. The validity of these spectra is demonstrated by spectral analysis of a fireproof ceramic consisting of Al2O3 and of quartz and by an attempt to explain the origin of the CL properties of magmatic Zircon which is of significant importance in the field of geochronological investigations.

Au vu des intentions fondamentales de la fabrication des VLSI et des objectifs des programmes d'assurance de qualite et de controle de qualite, on voit apparaitre comme garantes du succes trois technologies, qui sont la metrologie dimensionnelle, l'analyse des materiaux et les methodes statistiques de controle des processus. La multiplicite stupefiante des methodes, les options instrumentales, des etats et variables des processus a controler, font les controles de qualite et assurance de qualite aussi complexes que la fabrication meme des VLSI et demandent un engagement a long terme des equipes de direction, d'ingenieurs et de techniciens

Recent advances in the analysis of industrial fatty acids and their derivatives almost always involve complex instrumentation. One of the most important developments in the analysis of fatty acids and their derivatives was the application of gas chromatography (GC). The result has been so effective that the time-consuming fractional distillation and detailed analysis of fractions previously employed are rarely used. Even though the so-called GLC technique has now been applied for over twenty years, new advances continue to be made in this area. Perhaps the most potentially valuable new development is the coupling of GLC with mass spectrometry (GLC-MS). Two newer chromatographic methods which have great potential in the field of fatty material analysis are thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). The former is applicable to difficult separations; e.g., separation of broad lipid classes, in microquantities. The latter has already been applied with some success to the separation of individual component triglycerides of fats and oils and fatty acids using reverse phase HPLC. Instrumentation techniques include supportive methods which are frequently used in conjunction with other methods. Among these, the techniques of nuclear magnetic resonance (NMR) and infrared absorption (IR) are the most prominent.13C NMR is useful in defining fine structure of fatty acids, particularly with respect to branching. X-ray diffraction is used to study polymorphism in fatty acids.

Green and medium-roast Kenyan arabica coffees were ground and sieved, and the 0·85–1·8 mm size fractions partially converted into two water-swollen forms by an appropriate series of treatments. The first form still contained a mix of coffee solubles, the second only caffeine. The rates of caffeine infusion into water at 80°C were then measured for the dry coffee and for the two water-swollen preparations. The caffeine was extracted two to three times faster from the solute-free water-swollen preparation than from the dry material Analysis of the results showed that counterflow of water the swelling of coffee particles, caffeine association with other solubes and physical restraints within the bean matrix all contribute to the low diffusion coefficient of caffeine inside the coffee particles. The behaviour of the green and the medium roast coffees was surprisingly similar.