Recommended Today

1952

The Elastic Behaviour of a Crystalline Aggregate

0 Read(s)

The connection between the elastic behaviour of an aggregate and a single crystal is considered, with special reference to the theories of Voigt, Reuss, and Huber and Schmid. The elastic limit under various stress systems is also considered, in particular, it is shown that the tensile elastic limit of a face-centred aggregate cannot exceed two-thirds of the stress at which pronounced plastic distortion occurs.

2000 - Academy of Management Journal

Consequences of Abusive Supervision

Drawing on justice theory, the author examined the consequences of abusive supervisor behavior. As expected, subordinates who perceived their supervisors were more abusive were more likely to quit their jobs. For subordinates who remained with their jobs, abusive supervision was associated with lower job and life satisfaction, lower normative and affective commitment, and higher continuance commitment, conflict between work and family, and psychological distress. Organizational justice mediated most of these effects, and job mobility moderated some of the deleterious effects of abusive supervision.

1947 - The Journal of General Physiology

CRYSTALLINE SOYBEAN TRYPSIN INHIBITOR : II. GENERAL PROPERTIES.

0 Read(s)

A study has been made of the general properties of crystalline soybean trypsin inhibitor. The soy inhibitor is a stable protein of the globulin type of a molecular weight of about 24,000. Its isoelectric point is at pH 4.5. It inhibits the proteolytic action approximately of an equal weight of crystalline trypsin by combining with trypsin to form a stable compound. Chymotrypsin is only slightly inhibited by soy inhibitor. The reaction between chymotrypsin and the soy inhibitor consists in the formation of a reversibly dissociable compound. The inhibitor has no effect on pepsin. The inhibiting action of the soybean inhibitor is associated with the native state of the protein molecule. Denaturation of the soy protein by heat or acid or alkali brings about a proportional decrease in its inhibiting action on trypsin. Reversal of denaturation results in a proportional gain in the inhibiting activity. Crystalline soy protein when denatured is readily digestible by pepsin, and less readily by chymotrypsin and by trypsin. Methods are given for measuring trypsin and inhibitor activity and also protein concentration with the aid of spectrophotometric density measurements at 280 mµ.

2011

"BUILDING CODE REQUIREMENTS FOR STRUCTURAL CONCRETE (ACI 318-11) AND COMMENTARY"

The “Building Code Requirements for Structural Concrete” (“Code”) covers the materials, design, and construction of structural concrete used in buildings and where applicable in nonbuilding structures. The Code also covers the strength evaluation of existing concrete structures. Among the subjects covered are: contract documents; inspection; materials; durability requirements; concrete quality, mixing, and placing; formwork; embedded pipes; construction joints; reinforcement details; analysis and design; strength and serviceability; flexural and axial loads; shear and torsion; development and splices of reinforcement; slab systems; walls; footings; precast concrete; composite flexural members; prestressed concrete; shells and folded plate members; strength evaluation of existing structures; provisions for seismic design; structural plain concrete; strut-and-tie modeling in Appendix A; alternative design provisions in Appendix B; alternative load and strength reduction factors in Appendix C; and anchoring to concrete in Appendix D. The quality and testing of materials used in construction are covered by reference to the appropriate ASTM standard specifications. Welding of reinforcement is covered by reference to the appropriate American Welding Society (AWS) standard. Uses of the Code include adoption by reference in general building codes, and earlier editions have been widely used in this manner. The Code is written in a format that allows such reference without change to its language. Therefore, background details or suggestions for carrying out the requirements or intent of the Code portion cannot be included. The Commentary is provided for this purpose. Some of the considerations of the committee in developing the Code portion are discussed within the Commentary, with emphasis given to the explanation of new or revised provisions. Much of the research data referenced in preparing the Code is cited for the user desiring to study individual questions in greater detail. Other documents that provide suggestions for carrying out the requirements of the Code are also cited.

2001 - Journal of the American Chemical Society

Synthesis of highly crystalline and monodisperse maghemite nanocrystallites without a size-selection process.

The synthesis of highly crystalline and monodisperse gamma-Fe(2)O(3) nanocrystallites is reported. High-temperature (300 degrees C) aging of iron-oleic acid metal complex, which was prepared by the thermal decomposition of iron pentacarbonyl in the presence of oleic acid at 100 degrees C, was found to generate monodisperse iron nanoparticles. The resulting iron nanoparticles were transformed to monodisperse gamma-Fe(2)O(3) nanocrystallites by controlled oxidation by using trimethylamine oxide as a mild oxidant. Particle size can be varied from 4 to 16 nm by controlling the experimental parameters. Transmission electron microscopic images of the particles showed 2-dimensional and 3-dimensional assembly of particles, demonstrating the uniformity of these nanoparticles. Electron diffraction, X-ray diffraction, and high-resolution transmission electron microscopic (TEM) images of the nanoparticles showed the highly crystalline nature of the gamma-Fe(2)O(3) structures. Monodisperse gamma-Fe(2)O(3) nanocrystallites with a particle size of 13 nm also can be generated from the direct oxidation of iron pentacarbonyl in the presence of oleic acid with trimethylamine oxide as an oxidant.

2009 - Found. Trends Inf. Retr.

The Probabilistic Relevance Framework: BM25 and Beyond

The Probabilistic Relevance Framework (PRF) is a formal framework for document retrieval, grounded in work done in the 1970—1980s, which led to the development of one of the most successful text-retrieval algorithms, BM25. In recent years, research in the PRF has yielded new retrieval models capable of taking into account document meta-data (especially structure and link-graph information). Again, this has led to one of the most successful Web-search and corporate-search algorithms, BM25F. This work presents the PRF from a conceptual point of view, describing the probabilistic modelling assumptions behind the framework and the different ranking algorithms that result from its application: the binary independence model, relevance feedback models, BM25 and BM25F. It also discusses the relation between the PRF and other statistical models for IR, and covers some related topics, such as the use of non-textual features, and parameter optimisation for models with free parameters.

1997

Interfaces in Crystalline Materials

The geometry of interfaces Dislocation for interfaces Models of interatomic forces at interfaces Models and experimental observations of structure Thermodynamics of interfaces Interface phases and phase transitions Segregation of solute atoms to interfaces Diffusion at interfaces Conservative motion of interfaces Non-conservative motion of interfaces: interfaces as sources/sinks for diffusional fluxes of atoms Electronic properties of interfaces Mechanical properties of interfaces.

2012 - PLoS Computational Biology

Ten Years of Pathway Analysis: Current Approaches and Outstanding Challenges

Pathway analysis has become the first choice for gaining insight into the underlying biology of differentially expressed genes and proteins, as it reduces complexity and has increased explanatory power. We discuss the evolution of knowledge base–driven pathway analysis over its first decade, distinctly divided into three generations. We also discuss the limitations that are specific to each generation, and how they are addressed by successive generations of methods. We identify a number of annotation challenges that must be addressed to enable development of the next generation of pathway analysis methods. Furthermore, we identify a number of methodological challenges that the next generation of methods must tackle to take advantage of the technological advances in genomics and proteomics in order to improve specificity, sensitivity, and relevance of pathway analysis.

2005 - IEEE Transactions on Power Systems

Causes of the 2003 major grid blackouts in North America and Europe, and recommended means to improve system dynamic performance

On August 14, 2003, a cascading outage of transmission and generation facilities in the North American Eastern Interconnection resulted in a blackout of most of New York state as well as parts of Pennsylvania, Ohio, Michigan, and Ontario, Canada. On September 23, 2003, nearly four million customers lost power in eastern Denmark and southern Sweden following a cascading outage that struck Scandinavia. Days later, a cascading outage between Italy and the rest of central Europe left most of Italy in darkness on September 28. These major blackouts are among the worst power system failures in the last few decades. The Power System Stability and Power System Stability Controls Subcommittees of the IEEE PES Power System Dynamic Performance Committee sponsored an all day panel session with experts from around the world. The experts described their recent work on the investigation of grid blackouts. The session offered a unique forum for discussion of possible root causes and necessary steps to reduce the risk of blackouts. This white paper presents the major conclusions drawn from the presentations and ensuing discussions during the all day session, focusing on the root causes of grid blackouts. This paper presents general conclusions drawn by this Committee together with recommendations based on lessons learned.

2003

Underneath the Bragg Peaks: Structural Analysis of Complex Materials

This book focuses on the structural determination of crystalline solids with extensive disorder. Well-established methods exist for characterizing the structure of fully crystalline solids or fully disordered materials such as liquids and glasses, but there is a dearth of techniques for the cases in-between, crystalline solids with internal atomic and nanometer scale disorder. Egami and Billinge discuss how to fill the gap using modern tools of structural characterization. This problem is encountered in the structural characterization of a surprisingly wide range of complex materials of interest to modern technology and is becoming increasingly important. Takeshi Egami received the 2003 Eugene Bertram Warren Diffraction Physics Award for the work described in the book. The authors received 2010 J. D. Hanawalt Award from the International Union of Crystallography largely based on the success of this book Praise for the first edition: Egami and Billinge are experts in the application of PDF analysis and their writing is both clear and insightful. The organisation of the book is also excellent, with illuminating examples provided throughout. If you have an interest in atomic structure of materials, and local structural details in particular, PDF methods can be profoundly useful. I would heartily recommend this book as a starting point if you are considering using PDF analysis in your own work. For more experienced practitioners, this text is a useful reference. Materials Today, June 2004 introduces a unique method to study the atomic structure of nanomaterials. It lays out the basic theory and methods of this important emerging technique. The first edition is considered the seminal text on the subject.

1961 - Journal of Applied Physics

Sintering Crystalline Solids. I. Intermediate and Final State Diffusion Models

0 Read(s)

Photomicrographs of pore and grain boundary structures in sintered powder compacts are presented to provide the basis for qualitative description of the important phases of the course of densification. From this guide, appropriate grain shapes and pore shapes and locations are selected for the formulation of diffusion sintering models. The principle models presented are for bulk diffusion transport with the grain boundaries as vacancy sinks when the pore phase is continuous and coincident with three grain edges, and also when the pore phase is discontinuous and located at four-grain corners. These models predict that the rate of density change is constant when the diffusion coefficient and grain size are constant. The need for simultaneous isothermal densification and grain growth data is indicated. The explicit change in densification rate with discontinuous grain growth is predicted in terms of pore spacing and grain size.

2007 - Journal of The Electrochemical Society

Reversible Cycling of Crystalline Silicon Powder

A method is described in which crystalline silicon can be used as a practical anode material for lithium-ion batteries. Commercial lithium-ion cells are typically charged at a constant current to a fixed voltage and then are held by the charger at constant voltage until the current decreases to a certain value (also known as constant current/constant voltage or CCCV charging). It is first shown that CCCV charging can be used to reversibly cycle crystalline silicon and limit its capacity. A cycling method is then demonstrated in which crystalline silicon is first partially converted to amorphous silicon, in situ, during conditioning cycles. After the conditioning cycles the silicon can be cycled normally, using CCCV cycling limits, with good coulombic efficiency and little overlithiation during the first cycle.

2017 - Advanced Functional Materials

Flexible MXene/Graphene Films for Ultrafast Supercapacitors with Outstanding Volumetric Capacitance

A strategy to prepare flexible and conductive MXene/graphene (reduced graphene oxide, rGO) supercapacitor electrodes by using electrostatic self-assembly between positively charged rGO modified with poly(diallyldimethylammonium chloride) and negatively charged titanium carbide MXene nanosheets is presented. After electrostatic assembly, rGO nanosheets are inserted in-between MXene layers. As a result, the self-restacking of MXene nanosheets is effectively prevented, leading to a considerably increased interlayer spacing. Accelerated diffusion of electrolyte ions enables more electroactive sites to become accessible. The freestanding MXene/rGO-5 wt% electrode displays a volumetric capacitance of 1040 F cm−3 at a scan rate of 2 mV s−1 , an impressive rate capability with 61% capacitance retention at 1 V s−1 and long cycle life. Moreover, the fabricated binder-free symmetric supercapacitor shows an ultrahigh volumetric energy density of 32.6 Wh L−1, which is among the highest values reported for carbon and MXene based materials in aqueous electrolytes. This work provides fundamental insight into the effect of interlayer spacing on the electrochemical performance of 2D hybrid materials and sheds light on the design of next-generation flexible, portable and highly integrated supercapacitors with high volumetric and rate performances.

2005 - International journal of food microbiology

GInaFiT, a freeware tool to assess non-log-linear microbial survivor curves.

This contribution focuses on the presentation of GInaFiT (Geeraerd and Van Impe Inactivation Model Fitting Tool), a freeware Add-in for Microsoft Excel aiming at bridging the gap between people developing predictive modelling approaches and end-users in the food industry not familiar with or not disposing over advanced non-linear regression analysis tools. More precisely, the tool is useful for testing nine different types of microbial survival models on user-specific experimental data relating the evolution of the microbial population with time. As such, the authors believe to cover all known survivor curve shapes for vegetative bacterial cells. The nine model types are: (i) classical log-linear curves, (ii) curves displaying a so-called shoulder before a log-linear decrease is apparent, (iii) curves displaying a so-called tail after a log-linear decrease, (iv) survival curves displaying both shoulder and tailing behaviour, (v) concave curves, (vi) convex curves, (vii) convex/concave curves followed by tailing, (viii) biphasic inactivation kinetics, and (ix) biphasic inactivation kinetics preceded by a shoulder. Next to the obtained parameter values, the following statistical measures are automatically reported: standard errors of the parameter values, the Sum of Squared Errors, the Mean Sum of Squared Errors and its Root, the R(2) and the adjusted R(2). The tool can help the end-user to communicate the performance of food preservation processes in terms of the number of log cycles of reduction rather than the classical D-value and is downloadable via the KULeuven/BioTeC-homepage at the topic "Downloads" (Version 1.4, Release date April 2005).

1989 - Proceedings of the National Academy of Sciences of the United States of America

Quantitation of mRNA by the polymerase chain reaction.

A method for the quantitation of specific mRNA species by the polymerase chain reaction (PCR) has been developed by using a synthetic RNA as an internal standard. The specific target mRNA and the internal standard are coamplified in one reaction in which the same primers are used. The amount of mRNA is then quantitated by extrapolating against the standard curve generated with the internal standard. The synthetic internal standard RNA consists of a linear array of the sequences of upstream primers of multiple target genes followed by the complementary sequences to their downstream primers in the same order. This quantitative PCR method provides a rapid and reliable way to quantify the amount of a specific mRNA in a sample of less than 0.1 ng of total RNA. In addition, the same internal standard RNA is used, with appropriate primer pairs, to quantitate multiple different mRNA species.

1947 - The Journal of General Physiology

CRYSTALLINE SOYBEAN TRYPSIN INHIBITOR

0 Read(s)

A study has been made of the general properties of crystalline soybean trypsin inhibitor. The soy inhibitor is a stable protein of the globulin type of a molecular weight of about 24,000. Its isoelectric point is at pH 4.5. It inhibits the proteolytic action approximately of an equal weight of crystalline trypsin by combining with trypsin to form a stable compound. Chymotrypsin is only slightly inhibited by soy inhibitor. The reaction between chymotrypsin and the soy inhibitor consists in the formation of a reversibly dissociable compound. The inhibitor has no effect on pepsin. The inhibiting action of the soybean inhibitor is associated with the native state of the protein molecule. Denaturation of the soy protein by heat or acid or alkali brings about a proportional decrease in its inhibiting action on trypsin. Reversal of denaturation results in a proportional gain in the inhibiting activity. Crystalline soy protein when denatured is readily digestible by pepsin, and less readily by chymotrypsin and by trypsin. Methods are given for measuring trypsin and inhibitor activity and also protein concentration with the aid of spectrophotometric density measurements at 280 mµ.

1973 - Journal of the Soil Mechanics and Foundations Division

Analysis of Ultimate Loads of Shallow Foundations

The paper presents a modern outlook of the problem of bearing capacity of shallow foundations, incorporating all major contributions to the subject, along with best available solutions and appropriate numerical values of bearing capacity factors and coefficients. It is shown that the greatest shortcoming of available theories lies in their unreserved assumption of incompressibility of the foundation soil. An attempt is made to formulate for the first time rational compressibility criteria for soils subjected to foundation loads. A set of tentative compressibility factors, to be used with the classical bearing capacity equation, are given. The paper includes an analysis of the effects on bearing capacity of roughness and vertical profile of foundation base, ground-water table, presence of adjacent footings and rate of loading.

2002 - The Journal of applied psychology

Abusive supervision and subordinates' organizational citizenship behavior.

The relationship between subordinates' perceptions of abusive supervision and supervisors' evaluations of subordinates' organizational citizenship behavior (OCB) was explored among a sample of 373 Air National Guard members and their military supervisors. As predicted, the relationship between abusive supervision and subordinates' OCB was stronger among subordinates who defined OCB as extra-role behavior (compared with those defining OCB as in-role behavior), and this effect was fully mediated by the interactive effect of procedural justice and OCB role definitions. The study's implications for theory and research are discussed, its limitations are identified, and directions for future research are suggested.

2012

Map Projections: A Working Manual

0 Read(s)

If projection is not specified here it uses proj='aeqd' (azimuthal equidistant). Returns: grid: grid object (R39), Snyder, J. P. Map Projections–A Working Manual. This web page relates to the PROJ.4 Cartographic Projections library ​OF90-284.pdf (2.7MB): The main users manual for PROJ, however, this VerticalDatums working notes on the project to support vertical datums in ​ Map projections: An introduction to cartography emphasizing map projections: their properties. Abstract The approach to map projections in which maps (using geometric principles) from a sphere Snyder JP (1987) Map projections: a working manual.

2003 - Free radical biology & medicine

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) generation by silica in inflammation and fibrosis.

Exposure to particulate silica (most crystalline polymorphs) causes a persistent inflammation sustained by the release of oxidants in the alveolar space. Reactive oxygen species (ROS), which include hydroxyl radical, superoxide anion, hydrogen peroxide, and singlet oxygen, are generated not only at the particle surface, but also by phagocytic cells attempting to digest the silica particle. Two distinct kinds of surface centers-silica-based surface radicals and poorly coordinated iron ions-generate O(2)(*)(-) and HO(*) in aqueous solution via different mechanisms. Crystalline silica is also a potent stimulant of the respiratory burst in phagocytic cells with increased oxygen consumption and production of O(*)(-), H(2)O(2), and NO leading to acute inflammation and HO(*) generation in the lung. Oxidative stress elicited by crystalline silica is also evidenced by increased expression of antioxidant enzymes such as manganese superoxide dismutase (Mn-SOD) and glutathione peroxidase, and the enzyme inducible nitric oxide synthase (iNOS). Generation of oxidants by crystalline silica particles and by silica-activated cells results in cell and lung injury, activation of cell signaling pathways to include MAPK/ERK kinase (MEK), and extracellular signal-regulated kinase (ERK) phosphorylation, increased expression of inflammatory cytokines (e.g., tumor necrosis factoralpha [TNFalpha], interleukin-1 [IL-1]), and activation of specific transcription factors (e.g., NFkappaB, AP-1). Silica can also initiate apoptosis in response to oxygen- and nitrogen-based free radicals, leading to mitochondrial dysfunction, increased gene expression of death receptors, and/or their ligands (TNFalpha, Fas ligand [FasL]).

Paper Keywords

neural network control system nonlinear system linear system publisher summary output feedback fuzzy system liquid crystal mechanical property bearing capacity time-varying delay cost function state feedback optical property time-delay system uncertain system cost control uncertain nonlinear uncertain nonlinear system amino acid output feedback controller clas of uncertain building code guaranteed cost markovian jump state feedback controller jump system guaranteed cost control discrete-time linear system electrical property uncertain linear x-ray diffraction uncertain linear system markovian jump system ion battery shallow foundation porous material linear time-delay system formal framework guaranteed cost controller structural concrete american concrete institute uncertain discrete-time foundation settlement polymer electrolyte uncertain time-delay system uncertain time-delay electronic property recycled concrete liquid crystalline cost control problem concrete aggregate concrete institute combined loading american concrete quadratic cost function crystalline silicon design of structural recycled concrete aggregate state and input charge carrier differential graded robust guaranteed cost optimal guaranteed cost discrete-time uncertain recent approach shear design discrete-time uncertain system optimal guaranteed cascading outage bearing capacity factor silicon film capacity of shallow solid dispersion abusive language first-principles study crystalline material crystalline silica uncertain discrete-time linear non-fragile guaranteed cost liquid crystalline polymer non-fragile guaranteed single crystalline internal standard crystalline polymer crystalline solid delay-dependent guaranteed cost crystalline structure ionic conductivity discrete-time uncertain nonlinear guaranteed cost function discrete-time uncertain linear vinylidene fluoride quadratic guaranteed cost closed-loop cost function microcrystalline silicon synthesi of highly crystalline phase amorphous phase abusive supervision crystalline rock