Mechanism of the superior mechanical strength of nanometer-sized metal single crystals revealed

KAUST Repository

Afify, N. D.

2013-10-01

Clear understanding of the superior mechanical strength of nanometer-sized metal single crystals is required to derive advanced mechanical components retaining such superiority. Although high quality studies have been reported on nano-crystalline metals, the superiority of small single crystals has neither been fundamentally explained nor quantified to this date. Here we present a molecular dynamics study of aluminum single crystals in the size range from 4.1 nm to 40.5 nm. We show that the ultimate mechanical strength deteriorates exponentially as the single crystal size increases. The small crystals superiority is explained by their ability to continuously form vacancies and to recover them. © 2013 Published by Elsevier B.V.

Fundamentals of physics II electromagnetism, optics, and quantum mechanics

CERN Document Server

Shankar, R

2016-01-01

R. Shankar, a well-known physicist and contagiously enthusiastic educator, was among the first to offer a course through the innovative Open Yale Course program. His popular online video lectures on introductory physics have been viewed over a million times. In this second book based on his online Yale course, Shankar explains essential concepts, including electromagnetism, optics, and quantum mechanics. The book begins at the simplest level, develops the basics, and reinforces fundamentals, ensuring a solid foundation in the principles and methods of physics. It provides an ideal introduction for college-level students of physics, chemistry, and engineering; for motivated AP Physics students; and for general readers interested in advances in the sciences.

Spatiotemporal mechanical variation reveals critical role for rho kinase during primitive streak morphogenesis.

Science.gov (United States)

Henkels, Julia; Oh, Jaeho; Xu, Wenwei; Owen, Drew; Sulchek, Todd; Zamir, Evan

2013-02-01

Large-scale morphogenetic movements during early embryo development are driven by complex changes in biochemical and biophysical factors. Current models for amniote primitive streak morphogenesis and gastrulation take into account numerous genetic pathways but largely ignore the role of mechanical forces. Here, we used atomic force microscopy (AFM) to obtain for the first time precise biomechanical properties of the early avian embryo. Our data reveal that the primitive streak is significantly stiffer than neighboring regions of the epiblast, and that it is stiffer than the pre-primitive streak epiblast. To test our hypothesis that these changes in mechanical properties are due to a localized increase of actomyosin contractility, we inhibited actomyosin contractility via the Rho kinase (ROCK) pathway using the small-molecule inhibitor Y-27632. Our results using several different assays show the following: (1) primitive streak formation was blocked; (2) the time-dependent increase in primitive streak stiffness was abolished; and (3) convergence of epiblast cells to the midline was inhibited. Taken together, our data suggest that actomyosin contractility is necessary for primitive streak morphogenesis, and specifically, ROCK plays a critical role. To better understand the underlying mechanisms of this fundamental process, future models should account for the findings presented in this study.

When fast is better: protein folding fundamentals and mechanisms from ultrafast approaches.

Science.gov (United States)

Muñoz, Victor; Cerminara, Michele

2016-09-01

Protein folding research stalled for decades because conventional experiments indicated that proteins fold slowly and in single strokes, whereas theory predicted a complex interplay between dynamics and energetics resulting in myriad microscopic pathways. Ultrafast kinetic methods turned the field upside down by providing the means to probe fundamental aspects of folding, test theoretical predictions and benchmark simulations. Accordingly, experimentalists could measure the timescales for all relevant folding motions, determine the folding speed limit and confirm that folding barriers are entropic bottlenecks. Moreover, a catalogue of proteins that fold extremely fast (microseconds) could be identified. Such fast-folding proteins cross shallow free energy barriers or fold downhill, and thus unfold with minimal co-operativity (gradually). A new generation of thermodynamic methods has exploited this property to map folding landscapes, interaction networks and mechanisms at nearly atomic resolution. In parallel, modern molecular dynamics simulations have finally reached the timescales required to watch fast-folding proteins fold and unfold in silico All of these findings have buttressed the fundamentals of protein folding predicted by theory, and are now offering the first glimpses at the underlying mechanisms. Fast folding appears to also have functional implications as recent results connect downhill folding with intrinsically disordered proteins, their complex binding modes and ability to moonlight. These connections suggest that the coupling between downhill (un)folding and binding enables such protein domains to operate analogically as conformational rheostats. © 2016 The Author(s).

Comparative analysis reveals the underlying mechanism of vertebrate seasonal reproduction.

Science.gov (United States)

Ikegami, Keisuke; Yoshimura, Takashi

2016-02-01

Animals utilize photoperiodic changes as a calendar to regulate seasonal reproduction. Birds have highly sophisticated photoperiodic mechanisms and functional genomics analysis in quail uncovered the signal transduction pathway regulating avian seasonal reproduction. Birds detect light with deep brain photoreceptors. Long day (LD) stimulus induces secretion of thyroid-stimulating hormone (TSH) from the pars tuberalis (PT) of the pituitary gland. PT-derived TSH locally activates thyroid hormone (TH) in the hypothalamus, which induces gonadotropin-releasing hormone (GnRH) and hence gonadotropin secretion. However, during winter, low temperatures increase serum TH for adaptive thermogenesis, which accelerates germ cell apoptosis by activating the genes involved in metamorphosis. Therefore, TH has a dual role in the regulation of seasonal reproduction. Studies using TSH receptor knockout mice confirmed the involvement of PT-derived TSH in mammalian seasonal reproduction. In addition, studies in mice revealed that the tissue-specific glycosylation of TSH diversifies its function in the circulation to avoid crosstalk. In contrast to birds and mammals, one of the molecular machineries necessary for the seasonal reproduction of fish are localized in the saccus vasculosus from the photoreceptor to the neuroendocrine output. Thus, comparative analysis is a powerful tool to uncover the universality and diversity of fundamental properties in various organisms. Copyright © 2015 Elsevier Inc. All rights reserved.

Fundamental transport mechanisms, fabrication and potential applications of nanoporous atomically thin membranes.

Science.gov (United States)

Wang, Luda; Boutilier, Michael S H; Kidambi, Piran R; Jang, Doojoon; Hadjiconstantinou, Nicolas G; Karnik, Rohit

2017-06-06

Graphene and other two-dimensional materials offer a new approach to controlling mass transport at the nanoscale. These materials can sustain nanoscale pores in their rigid lattices and due to their minimum possible material thickness, high mechanical strength and chemical robustness, they could be used to address persistent challenges in membrane separations. Here we discuss theoretical and experimental developments in the emerging field of nanoporous atomically thin membranes, focusing on the fundamental mechanisms of gas- and liquid-phase transport, membrane fabrication techniques and advances towards practical application. We highlight potential functional characteristics of the membranes and discuss applications where they are expected to offer advantages. Finally, we outline the major scientific questions and technological challenges that need to be addressed to bridge the gap from theoretical simulations and proof-of-concept experiments to real-world applications.

Fundamental transport mechanisms, fabrication and potential applications of nanoporous atomically thin membranes

Science.gov (United States)

Wang, Luda; Boutilier, Michael S. H.; Kidambi, Piran R.; Jang, Doojoon; Hadjiconstantinou, Nicolas G.; Karnik, Rohit

2017-06-01

Graphene and other two-dimensional materials offer a new approach to controlling mass transport at the nanoscale. These materials can sustain nanoscale pores in their rigid lattices and due to their minimum possible material thickness, high mechanical strength and chemical robustness, they could be used to address persistent challenges in membrane separations. Here we discuss theoretical and experimental developments in the emerging field of nanoporous atomically thin membranes, focusing on the fundamental mechanisms of gas- and liquid-phase transport, membrane fabrication techniques and advances towards practical application. We highlight potential functional characteristics of the membranes and discuss applications where they are expected to offer advantages. Finally, we outline the major scientific questions and technological challenges that need to be addressed to bridge the gap from theoretical simulations and proof-of-concept experiments to real-world applications.

On the relation between texture perception and fundamental mechanical parameters for liquids and time dependent solids

NARCIS (Netherlands)

Vliet, van T.

2002-01-01

Abstract Aspects of the relationship between texture perception in the mouth and fundamental mechanical parameters for liquids and time dependent solids are discussed. The emphasis is on the physical side of the relation. The importance is stressed of the incorporation of a thorough knowledge of

A numerical study of fundamental shock noise mechanisms. Ph.D. Thesis - Cornell Univ.

Science.gov (United States)

Meadows, Kristine R.

1995-01-01

The results of this thesis demonstrate that direct numerical simulation can predict sound generation in unsteady aerodynamic flows containing shock waves. Shock waves can be significant sources of sound in high speed jet flows, on helicopter blades, and in supersonic combustion inlets. Direct computation of sound permits the prediction of noise levels in the preliminary design stage and can be used as a tool to focus experimental studies, thereby reducing cost and increasing the probability of a successfully quiet product in less time. This thesis reveals and investigates two mechanisms fundamental to sound generation by shocked flows: shock motion and shock deformation. Shock motion is modeled by the interaction of a sound wave with a shock. During the interaction, the shock wave begins to move and the sound pressure is amplified as the wave passes through the shock. The numerical approach presented in this thesis is validated by the comparison of results obtained in a quasi-one dimensional simulation with linear theory. Analysis of the perturbation energy demonstrated for the first time that acoustic energy is generated by the interaction. Shock deformation is investigated by the numerical simulation of a ring vortex interacting with a shock. This interaction models the passage of turbulent structures through the shock wave. The simulation demonstrates that both acoustic waves and contact surfaces are generated downstream during the interaction. Analysis demonstrates that the acoustic wave spreads cylindrically, that the sound intensity is highly directional, and that the sound pressure level increases significantly with increasing shock strength. The effect of shock strength on sound pressure level is consistent with experimental observations of shock noise, indicating that the interaction of a ring vortex with a shock wave correctly models a dominant mechanism of shock noise generation.

Electrochemistry and capillary condensation theory reveal the mechanism of corrosion in dense porous media.

Science.gov (United States)

Stefanoni, Matteo; Angst, Ueli M; Elsener, Bernhard

2018-05-09

Corrosion in carbonated concrete is an example of corrosion in dense porous media of tremendous socio-economic and scientific relevance. The widespread research endeavors to develop novel, environmentally friendly cements raise questions regarding their ability to protect the embedded steel from corrosion. Here, we propose a fundamentally new approach to explain the scientific mechanism of corrosion kinetics in dense porous media. The main strength of our model lies in its simplicity and in combining the capillary condensation theory with electrochemistry. This reveals that capillary condensation in the pore structure defines the electrochemically active steel surface, whose variability upon changes in exposure relative humidity is accountable for the wide variability in measured corrosion rates. We performed experiments that quantify this effect and find good agreement with the theory. Our findings are essential to devise predictive models for the corrosion performance, needed to guarantee the safety and sustainability of traditional and future cements.

A combined cryo-EM and molecular dynamics approach reveals the mechanism of ErmBL-mediated translation arrest

Science.gov (United States)

Arenz, Stefan; Bock, Lars V.; Graf, Michael; Innis, C. Axel; Beckmann, Roland; Grubmüller, Helmut; Vaiana, Andrea C.; Wilson, Daniel N.

2016-07-01

Nascent polypeptides can induce ribosome stalling, regulating downstream genes. Stalling of ErmBL peptide translation in the presence of the macrolide antibiotic erythromycin leads to resistance in Streptococcus sanguis. To reveal this stalling mechanism we obtained 3.6-Å-resolution cryo-EM structures of ErmBL-stalled ribosomes with erythromycin. The nascent peptide adopts an unusual conformation with the C-terminal Asp10 side chain in a previously unseen rotated position. Together with molecular dynamics simulations, the structures indicate that peptide-bond formation is inhibited by displacement of the peptidyl-tRNA A76 ribose from its canonical position, and by non-productive interactions of the A-tRNA Lys11 side chain with the A-site crevice. These two effects combine to perturb peptide-bond formation by increasing the distance between the attacking Lys11 amine and the Asp10 carbonyl carbon. The interplay between drug, peptide and ribosome uncovered here also provides insight into the fundamental mechanism of peptide-bond formation.

Fundamentals of Diesel Engines.

Science.gov (United States)

Marine Corps Inst., Washington, DC.

This student guide, one of a series of correspondence training courses designed to improve the job performance of members of the Marine Corps, deals with the fundamentals of diesel engine mechanics. Addressed in the three individual units of the course are the following topics: basic principles of diesel mechanics; principles, mechanics, and…

Fundamentals of 3D Deployable Mechanisms in Space

Data.gov (United States)

National Aeronautics and Space Administration — Fundamentals of 3D Deployable Origami Structures in Space The primary objectives of my research are to study the application of 3D deployable origami structures in...

Toward a fundamental mechanics. III

International Nuclear Information System (INIS)

Phipps, T.E. Jr.

1976-01-01

The possibility was examined of accomplishing the entirety of physical description by means of mechanics, without help from field-theoretical ideas. Apart from some easily obtained qualitative agreements with general descriptive features of nuclei and elementary particles, one was balked in this program by an inability to handle in purely mechanical terms the relativistic many-body problem. The latter problem is considered. No quantitative calculations are attempted, but three suggestions are made--each of a quite radical nature--concerning the reformulation that will be necessary to restore mechanics to the mainstream of physics

Fundamental and semi-global kinetic mechanisms for hydrocarbon combustion. Final report, March 1977-October 1980

Energy Technology Data Exchange (ETDEWEB)

Dryer, F L; Glassman, I; Brezinsky, K

1981-03-01

Over the past three and one half years, substantial research efforts of the Princeton Fuels Research Group have been directed towards the development of simplified mechanisms which would accurately describe the oxidation of hydrocarbons fuels. The objectives of this combustion research included the study of semi-empirical modeling (that is an overall description) of the chemical kinetic mechanisms of simple hydrocarbon fuels. Such fuels include the alkanes: ethane, propane, butane, hexane and octane as well as the critically important alkenes: ethene, propene and butene. As an extension to this work, the study of the detailed radical species characteristics of combustion systems was initiated as another major aspect of the program, with emphasis on the role of the OH and HO/sub 2/ radicals. Finally, the studies of important alternative fuel problems linked the program to longer range approaches to the energy supply question. Studies of alternative fuels composed the major elements of this area of the program. The efforts on methanol research were completed, and while the aromatics aspects of the DOE work have been a direct extension of efforts supported by the Air Force Office of Scientific Research, they represented a significant part of the overall research effort. The emphasis in the proposed program is to provide further fundamental understanding of the oxidation of hydrocarbon fuels which will be useful in guiding engineering approaches. Although the scope of program ranges from the fundamentals of chemical kinetics to that of alternative fuel combustion, the objective in mind is to provide insight and guidance to the understanding of practical combustion environments. The key to our approach has been our understanding of the fundamental combustion chemistry and its relation to the important practical combustion problems which exist in implementing energy efficient, alternate fuels technologies.

Country Fundamentals and Currency Excess Returns

Directory of Open Access Journals (Sweden)

Daehwan Kim

2014-06-01

Full Text Available We examine whether country fundamentals help explain the cross-section of currency excess returns. For this purpose, we consider fundamental variables such as default risk, foreign exchange rate regime, capital control as well as interest rate in the multi-factor model framework. Our empirical results show that fundamental factors explain a large part of the cross-section of currency excess returns. The zero-intercept restriction of the factor model is not rejected for most currencies. They also reveal that our factor model with country fundamentals performs better than a factor model with usual investment-style factors. Our main empirical results are based on 2001-2010 balanced panel data of 19 major currencies. This paper may fill the gap between country fundamentals and practitioners' strategies on currency investment.

On the mechanical prototypes of fundamental hydrodynamic invariants and slow manifolds

Energy Technology Data Exchange (ETDEWEB)

Dolzhansky, Feliks V

2005-12-31

Arnol'd's group-theoretical concept of generalized rigid body includes the Euler equations of motion of the classical gyroscope and ideal homogeneous fluid as particular representatives. Here, this concept is extended to motion in force fields with a scalar or vector potential and in a Coriolis force field. The concepts of generalized heavy top and generalized MHD system are introduced. As particular cases, they include, on the one hand, the Euler-Poisson equations of the classical heavy top and the Kirchhoff equations of motion of a solid body in a potential flow of an ideal incompressible fluid and, on the other hand, the Oberbeck-Boussinesq equations of motion of a heavy fluid and MHD equations. On this basis, mechanical prototypes are constructed for all known fundamental hydrodynamic invariants and global geophysical flows, including a prototype of the general atmospheric circulation. (reviews of topical problems)

On the mechanical prototypes of fundamental hydrodynamic invariants and slow manifolds

International Nuclear Information System (INIS)

Dolzhansky, Feliks V

2005-01-01

Arnol'd's group-theoretical concept of generalized rigid body includes the Euler equations of motion of the classical gyroscope and ideal homogeneous fluid as particular representatives. Here, this concept is extended to motion in force fields with a scalar or vector potential and in a Coriolis force field. The concepts of generalized heavy top and generalized MHD system are introduced. As particular cases, they include, on the one hand, the Euler-Poisson equations of the classical heavy top and the Kirchhoff equations of motion of a solid body in a potential flow of an ideal incompressible fluid and, on the other hand, the Oberbeck-Boussinesq equations of motion of a heavy fluid and MHD equations. On this basis, mechanical prototypes are constructed for all known fundamental hydrodynamic invariants and global geophysical flows, including a prototype of the general atmospheric circulation. (reviews of topical problems)

Fundamentals of Structural Geology

Science.gov (United States)

Pollard, David D.; Fletcher, Raymond C.

2005-09-01

Fundamentals of Structural Geology provides a new framework for the investigation of geological structures by integrating field mapping and mechanical analysis. Assuming a basic knowledge of physical geology, introductory calculus and physics, it emphasizes the observational data, modern mapping technology, principles of continuum mechanics, and the mathematical and computational skills, necessary to quantitatively map, describe, model, and explain deformation in Earth's lithosphere. By starting from the fundamental conservation laws of mass and momentum, the constitutive laws of material behavior, and the kinematic relationships for strain and rate of deformation, the authors demonstrate the relevance of solid and fluid mechanics to structural geology. This book offers a modern quantitative approach to structural geology for advanced students and researchers in structural geology and tectonics. It is supported by a website hosting images from the book, additional colour images, student exercises and MATLAB scripts. Solutions to the exercises are available to instructors. The book integrates field mapping using modern technology with the analysis of structures based on a complete mechanics MATLAB is used to visualize physical fields and analytical results and MATLAB scripts can be downloaded from the website to recreate textbook graphics and enable students to explore their choice of parameters and boundary conditions The supplementary website hosts color images of outcrop photographs used in the text, supplementary color images, and images of textbook figures for classroom presentations The textbook website also includes student exercises designed to instill the fundamental relationships, and to encourage the visualization of the evolution of geological structures; solutions are available to instructors

Predictive information processing is a fundamental learning mechanism present in early development: evidence from infants.

Science.gov (United States)

Trainor, Laurel J

2012-02-01

Evidence is presented that predictive coding is fundamental to brain function and present in early infancy. Indeed, mismatch responses to unexpected auditory stimuli are among the earliest robust cortical event-related potential responses, and have been measured in young infants in response to many types of deviation, including in pitch, timing, and melodic pattern. Furthermore, mismatch responses change quickly with specific experience, suggesting that predictive coding reflects a powerful, early-developing learning mechanism. Copyright © 2011 Elsevier B.V. All rights reserved.

Quantum mechanics a fundamental approach

CERN Document Server

Wan, K Kong

2018-01-01

The mathematical formalism of quantum theory in terms of vectors and operators in infinite-dimensional complex vector spaces is very abstract. The definitions of many mathematical quantities used do not seem to have an intuitive meaning. This makes it difficult to appreciate the mathematical formalism and hampers the understanding of quantum mechanics. This book provides intuition and motivation to the mathematics of quantum theory, introducing the mathematics in its simplest and familiar form, for instance, with three-dimensional vectors and operators, which can be readily understood. Feeling confident about and comfortable with the mathematics used helps readers appreciate and understand the concepts and formalism of quantum mechanics. Quantum mechanics is presented in six groups of postulates. A chapter is devoted to each group of postulates with a detailed discussion. Systems with superselection rules, and some conceptual issues such as quantum paradoxes and measurement, are also discussed. The book conc...

Fundamentals of turbomachines

CERN Document Server

Dick, Erik

2015-01-01

This book explores the working principles of all kinds of turbomachines. The same theoretical framework is used to analyse the different machine types. Fundamentals are first presented and theoretical concepts are then elaborated for particular machine types, starting with the simplest ones.For each machine type, the author strikes a balance between building basic understanding and exploring knowledge of practical aspects. Readers are invited through challenging exercises to consider how the theory applies to particular cases and how it can be generalised.   The book is primarily meant as a course book. It teaches fundamentals and explores applications. It will appeal to senior undergraduate and graduate students in mechanical engineering and to professional engineers seeking to understand the operation of turbomachines. Readers will gain a fundamental understanding of turbomachines. They will also be able to make a reasoned choice of turbomachine for a particular application and to understand its operation...

FUNDAMENTALS OF BIOMECHANICS

Directory of Open Access Journals (Sweden)

Duane Knudson

2007-09-01

Full Text Available DESCRIPTION This book provides a broad and in-depth theoretical and practical description of the fundamental concepts in understanding biomechanics in the qualitative analysis of human movement. PURPOSE The aim is to bring together up-to-date biomechanical knowledge with expert application knowledge. Extensive referencing for students is also provided. FEATURES This textbook is divided into 12 chapters within four parts, including a lab activities section at the end. The division is as follows: Part 1 Introduction: 1.Introduction to biomechanics of human movement; 2.Fundamentals of biomechanics and qualitative analysis; Part 2 Biological/Structural Bases: 3.Anatomical description and its limitations; 4.Mechanics of the musculoskeletal system; Part 3 Mechanical Bases: 5.Linear and angular kinematics; 6.Linear kinetics; 7.Angular kinetics; 8.Fluid mechanics; Part 4 Application of Biomechanics in Qualitative Analysis :9.Applying biomechanics in physical education; 10.Applying biomechanics in coaching; 11.Applying biomechanics in strength and conditioning; 12.Applying biomechanics in sports medicine and rehabilitation. AUDIENCE This is an important reading for both student and educators in the medicine, sport and exercise-related fields. For the researcher and lecturer it would be a helpful guide to plan and prepare more detailed experimental designs or lecture and/or laboratory classes in exercise and sport biomechanics. ASSESSMENT The text provides a constructive fundamental resource for biomechanics, exercise and sport-related students, teachers and researchers as well as anyone interested in understanding motion. It is also very useful since being clearly written and presenting several ways of examples of the application of biomechanics to help teach and apply biomechanical variables and concepts, including sport-related ones

Fundamentals of ion exchange

International Nuclear Information System (INIS)

Townsend, R.P.

1993-01-01

In this paper the fundamentals of ion exchange mechanisms and their thermodynamics are described. A range of ion exchange materials is considered and problems of communication and technology transfer between scientists working in the field are discussed. (UK)

Fundamentals of machine theory and mechanisms

CERN Document Server

Simón Mata, Antonio; Cabrera Carrillo, Juan Antonio; Ezquerro Juanco, Francisco; Guerra Fernández, Antonio Jesús; Nadal Martínez, Fernando; Ortiz Fernández, Antonio

2016-01-01

This book covers the basic contents for an introductory course in Mechanism and Machine Theory. The topics dealt with are: kinematic and dynamic analysis of machines, introduction to vibratory behaviour, rotor and piston balance, kinematics of gears, ordinary and planetary gear trains and synthesis of planar mechanisms. A new approach to dimensional synthesis of mechanisms based on turning functions has been added for closed and open path generation using an optimization method based on evolutionary algorithms. The text, developed by a group of experts in kinematics and dynamics of mechanisms at the University of Málaga, Spain, is clear and is supported by more than 350 images. More than 60 outlined and explained problems have been included to clarify the theoretical concepts. .

Possible Mechanism for the Generation of a Fundamental Unit of Charge (long version)

Energy Technology Data Exchange (ETDEWEB)

Lestone, John Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-06-16

Various methods for calculating particle-emission rates from hot systems are reviewed. Semi-classically derived photon-emission rates often contain the term exp(-ε/T) which needs to be replaced with the corresponding Planckian factor of [exp(-ε/T)-1]^-1 to obtain the correct rate. This replacement is associated with the existence of stimulated emission. Simple arguments are used to demonstrate that black holes can also undergo stimulated emission, as previously determined by others. We extend these concepts to fundamental particles, and assume they can be stimulated to emit virtual photons with a cross section of πλ², in the case of an isolated particle when the incident virtual-photon energy is < 2πmc². Stimulated-virtual photons can be exchanged with other particles generating a force. With the inclusion of near-field effects, the model choices presented give a calculated fundamental unit of charge of 1.6022x10^-19 C. If these choices are corroborated by detailed calculations then an understanding of the numerical value of the fine structure constant may emerge. The present study suggests charge might be an emergent property generated by a simple interaction mechanism between point-like particles and the electromagnetic vacuum, similar to the process that generates the Lamb shift.

Recrystallization - Fundamental aspects and relations to deformation microstructure

International Nuclear Information System (INIS)

Hansen, N.; Huang, X.; Juul Jensen, D.; Lauridsen, E.M.; Leffers, T.; Pantleon, W.; Sabin, T.J.; Wert, J.A.

2000-01-01

This Symposium, and hence this proceedings volume, is concerned with the mechanisms that control recrystallization of deformed metals and alloys. Central themes are the fundamental microstructural, orientational, and kinetic aspects of the recrystallization process; especially as they relate to the nature of the deformed state, to nucleation and growth of recrystallizing grains, and to models based on experimental observations. In recent years, significant progress has been made using a plethora of advanced techniques to characterize the morphology and local orientations in deformed metals and alloys. Thus, a key topic of the Symposium is enhanced insight into the characteristics of the deformation substructure, and into modification of the substructure by recovery, which is essential for understanding fundamental recrystallization mechanisms. Microstructures in highly strained materials will be a topic of special interest. Elucidation of the deformation substructure, and thus the local distribution of stored energy, sets the stage for progress in understanding nucleation of recrystallizing grains. It also provides a basis for new insights into the growth of nuclei, in particular concerning the means by which the deformation substructure is absorbed by and becomes incorporated into the recrystallization interface. Aspects of recrystallization of relevance to this symposium span the range from experimental and model exploration of fundamental mechanisms to methods that link scientific understanding to industrial practice. Models developed by considering the physical mechanisms elucidated by experimental studies will be addressed, as will models that enable industrial exploitation of the fundamental knowledge. Altogether, one of the significant aims of the symposium is to enhance the exploitation of the expanding knowledge of fundamental recrystallization mechanisms in industrial practice (au)

BOOK REVIEWS: Quantum Mechanics: Fundamentals

Science.gov (United States)

Whitaker, A.

2004-02-01

mechanics, which is assumed, but to examine whether it gives a consistent account of measurement. The conclusion is that after a measurement, interference terms are ‘effectively’ absent; the set of ‘one-to-one correlations between states of the apparatus and the object’ has the same form as that of everyday statistics and is thus a probability distribution. This probability distribution refers to potentialities, only one of which is actually realized in any one trial. Opinions may differ on whether their treatment is any less vulnerable to criticisms such as those of Bell. To sum up, Gottfried and Yan’s book contains a vast amount of knowledge and understanding. As well as explaining the way in which quantum theory works, it attempts to illuminate fundamental aspects of the theory. A typical example is the ‘fable’ elaborated in Gottfried’s article in Nature cited above, that if Newton were shown Maxwell’s equations and the Lorentz force law, he could deduce the meaning of E and B, but if Maxwell were shown Schrödinger’s equation, he could not deduce the meaning of Psi. For use with a well-constructed course (and, of course, this is the avowed purpose of the book; a useful range of problems is provided for each chapter), or for the relative expert getting to grips with particular aspects of the subject or aiming for a deeper understanding, the book is certainly ideal. It might be suggested, though, that, even compared to the first edition, the isolated learner might find the wide range of topics, and the very large number of mathematical and conceptual techniques, introduced in necessarily limited space, somewhat overwhelming. The second book under consideration, that of Schwabl, contains ‘Advanced’ elements of quantum theory; it is designed for a course following on from one for which Gottfried and Yan, or Schwabl’s own `Quantum Mechanics' might be recommended. It is the second edition in English, and is a translation of the third German edition

FUNDAMENTALIZATION OF ICT LEARNING IN MODERN HIGH TECH ENVIRONMENT

Directory of Open Access Journals (Sweden)

M. P. Shyshkina

2013-03-01

Full Text Available The article outlines the features of the process of fundamentalization of ICT learning, educational background to ensure it in high school. The concept of fundamental knowledge and its role in training of a specialist is described. The problems of access to qualitative education, particularly to electronic learning resources in modern high-tech environment are revealed. The role of computer mathematics as a tool of ICT learning fundamentalization is emphasized.

A systems approach to theoretical fluid mechanics: Fundamentals

Science.gov (United States)

Anyiwo, J. C.

1978-01-01

A preliminary application of the underlying principles of the investigator's general system theory to the description and analyses of the fluid flow system is presented. An attempt is made to establish practical models, or elements of the general fluid flow system from the point of view of the general system theory fundamental principles. Results obtained are applied to a simple experimental fluid flow system, as test case, with particular emphasis on the understanding of fluid flow instability, transition and turbulence.

The fundamentals of mathematical analysis

CERN Document Server

Fikhtengol'ts, G M

1965-01-01

The Fundamentals of Mathematical Analysis, Volume 1 is a textbook that provides a systematic and rigorous treatment of the fundamentals of mathematical analysis. Emphasis is placed on the concept of limit which plays a principal role in mathematical analysis. Examples of the application of mathematical analysis to geometry, mechanics, physics, and engineering are given. This volume is comprised of 14 chapters and begins with a discussion on real numbers, their properties and applications, and arithmetical operations over real numbers. The reader is then introduced to the concept of function, i

Size-dependent physicochemical and mechanical interactions in battery paste anodes of Si-microwires revealed by Fast-Fourier-Transform Impedance Spectroscopy

Science.gov (United States)

Hansen, Sandra; Quiroga-González, Enrique; Carstensen, Jürgen; Adelung, Rainer; Föll, Helmut

2017-05-01

Perfectly aligned silicon microwire arrays show exceptionally high cycling stability with record setting (high) areal capacities of 4.25 mAh cm-2. Those wires have a special, modified length and thickness in order to perform this good. Geometry and sizes are the most important parameters of an anode to obtain batteries with high cycling stability without irreversible losses. The wires are prepared with a unique etching fabrication method, which allows to fabricate wires of very precise sizes. In order to investigate how good randomly oriented silicon wires perform in contrast to the perfect order of the array, the wires are embedded in a paste. This study reveals the fundamental correlation between geometry, mechanics and charge transfer kinetics of silicon electrodes. Using a suitable RC equivalent circuit allows to evaluate data from cyclic voltammetry and simultaneous FFT-Impedance Spectroscopy (FFT-IS), yielding in time-resolved resistances, time constants, and their direct correlation to the phase transformations. The change of the resistances during lithiation and delithiation correlates to kinetics and charge transfer mechanisms. This study demonstrates how the mechanical and physiochemical interactions at the silicon/paste interface inside the paste electrodes lead to void formation around silicon and with it to material loss and capacity fading.

Geometric Mechanics Reveals Optimal Complex Terrestrial Undulation Patterns

Science.gov (United States)

Gong, Chaohui; Astley, Henry; Schiebel, Perrin; Dai, Jin; Travers, Matthew; Goldman, Daniel; Choset, Howie; CMU Team; GT Team

Geometric mechanics offers useful tools for intuitively analyzing biological and robotic locomotion. However, utility of these tools were previously restricted to systems that have only two internal degrees of freedom and in uniform media. We show kinematics of complex locomotors that make intermittent contacts with substrates can be approximated as a linear combination of two shape bases, and can be represented using two variables. Therefore, the tools of geometric mechanics can be used to analyze motions of locomotors with many degrees of freedom. To demonstrate the proposed technique, we present studies on two different types of snake gaits which utilize combinations of waves in the horizontal and vertical planes: sidewinding (in the sidewinder rattlesnake C. cerastes) and lateral undulation (in the desert specialist snake C. occipitalis). C. cerastes moves by generating posteriorly traveling body waves in the horizontal and vertical directions, with a relative phase offset equal to +/-π/2 while C. occipitalismaintains a π/2 offset of a frequency doubled vertical wave. Geometric analysis reveals these coordination patterns enable optimal movement in the two different styles of undulatory terrestrial locomotion. More broadly, these examples demonstrate the utility of geometric mechanics in analyzing realistic biological and robotic locomotion.

Fundamentals of quantum mechanics

CERN Document Server

Erkoc, Sakir

2006-01-01

HISTORICAL EXPERIMENTS AND THEORIESDates of Important Discoveries and Events Blackbody RadiationPhotoelectrice Effect Quantum Theory of Spectra TheComptone Effect Matterwaves, the de Broglie HypothesisThe Davisson -Germer Experiment Heisenberg's Uncertainity PrincipleDifference Between Particles and Waves Interpretation of the Wavefunction AXIOMATIC STRUCTURE OF QUANTUM MECHANICSThe Necessity of Quantum TheoryFunction Spaces Postulates of Quantum Mechanics The Kronecker Delta and the Dirac Delta Function Dirac Notation OBSERVABLES AND SUPERPOSITIONFree Particle Particle In A Box Ensemble Average Hilbert -Space Interpretation The Initial Square Wave Particle Beam Superposition and Uncertainty Degeneracy of States Commutators and Uncertainty TIME DEVELOPMENT AND CONSERVATION THEOREMSTime Development of State Functions, The Discrete Case The Continuous Case, Wave Packets Particle Beam Gaussian Wave Packet Free Particle Propagator The Limiting Cases of the Gaussian Wave Packets Time Development of Expectation Val...

Thermal and Mechanical Non-Equilibrium Effects on Turbulent Flows: Fundamental Studies of Energy Exchanges Through Direct Numerical Simulations, Molecular Simulations and Experiments

Science.gov (United States)

2016-02-26

photochemical TNE generation, and chemistry of non- equilibrium phenomena. We have investigated a new concept to generate turbulence using photo-initiated...AFRL-AFOSR-VA-TR-2016-0104 Thermal and mechanical non- equilibrium effects on turbulent flows:fundamental studies of energy exchanges through direct...Performance 3. DATES COVERED (From - To) 15-09-2012 to 14-11-2015 4. TITLE AND SUBTITLE Thermal and mechanical non- equilibrium effects on turbulent

Fundamentals of Biomass pellet production

DEFF Research Database (Denmark)

Holm, Jens Kai; Henriksen, Ulrik Birk; Hustad, Johan Einar

2005-01-01

Pelletizing experiments along with modelling of the pelletizing process have been carried out with the aim of understanding the fundamental physico-chemical mechanisms that control the quality and durability of biomass pellets. A small-scale California pellet mill (25 kg/h) located with the Biomass...

Variational principles of continuum mechanics I fundamentals

CERN Document Server

Berdichevskii, V L

2009-01-01

This is a concise and understandable book about variational principles of continuum mechanics. The book is accessible to applied mathematicians, physicists and engineers who have an interest in continuum mechanics.

Theoretical and quantum mechanics fundamentals for chemists

CERN Document Server

Ivanov, Stefan

2006-01-01

Provides the basics of theoretical and quantum mechanics in one place and emphasizes the continuity between themUniquely presented to be used for self-taught courses covering theoretical and quantum mechanicsEach chapter includes a detailed outline, a summary, self-assessment questions for which answers can be found in the textInvaluable for chemistry undergraduate and graduate students, chemists, other non-physical scientists, engineering students of modern techniques and technology, specialists who need a better understanding of quantum mechanics.

Double-lock ratchet mechanism revealing the role of  SER-344 in FoF1 ATP synthase

KAUST Repository

Beke-Somfai, T.; Lincoln, P.; Norden, B.

2011-01-01

In a majority of living organisms, FoF1 ATP synthase performs the fundamental process of ATP synthesis. Despite the simple net reaction formula, ADP+Pi→ATP+H2O, the detailed step-by-step mechanism of the reaction yet remains to be resolved owing

Mechanical properties of irradiated materials

International Nuclear Information System (INIS)

Robertson, I.M.; Robach, J.; Wirth, B.

2001-01-01

The effect of irradiation on the mechanical properties of metals is considered with particular attention being paid to the development of defect-free channels following uniaxial tensile loading. The in situ transmission electron microscope deformation technique is coupled with dislocation dynamic computer simulations to reveal the fundamental processes governing the elimination of defects by glissile dislocations. The observations of preliminary experiments are reported.(author)

Fundamental Processes of Coupled Radiation Damage and Mechanical Behavior in Nuclear Fuel Materials for High Temperature Reactors

Energy Technology Data Exchange (ETDEWEB)

Phillpot, Simon; Tulenko, James

2011-09-08

The objective of this work has been to elucidate the relationship among microstructure, radiation damage and mechanical properties for nuclear fuel materials. As representative nuclear materials, we have taken an hcp metal (Mg as a generic metal, and Ti alloys for fast reactors) and UO2 (representing fuel). The degradation of the thermo-mechanical behavior of nuclear fuels under irradiation, both the fissionable material itself and its cladding, is a longstanding issue of critical importance to the nuclear industry. There are experimental indications that nanocrystalline metals and ceramics may be more resistant to radiation damage than their coarse-grained counterparts. The objective of this project look at the effect of microstructure on radiation damage and mechanical behavior in these materials. The approach to be taken was state-of-the-art, large-scale atomic-level simulation. This systematic simulation program of the effects of irradiation on the structure and mechanical properties of polycrystalline Ti and UO2 identified radiation damage mechanisms. Moreover, it will provided important insights into behavior that can be expected in nanocrystalline microstructures and, by extension, nanocomposites. The fundamental insights from this work can be expected to help in the design microstructures that are less susceptible to radiation damage and thermomechanical degradation.

Fundamental Processes of Coupled Radiation Damage and Mechanical Behavior in Nuclear Fuel Materials for High Temperature Reactors

International Nuclear Information System (INIS)

Phillpot, Simon; Tulenko, James

2011-01-01

The objective of this work has been to elucidate the relationship among microstructure, radiation damage and mechanical properties for nuclear fuel materials. As representative nuclear materials, we have taken an hcp metal (Mg as a generic metal, and Ti alloys for fast reactors) and UO2 (representing fuel). The degradation of the thermo-mechanical behavior of nuclear fuels under irradiation, both the fissionable material itself and its cladding, is a longstanding issue of critical importance to the nuclear industry. There are experimental indications that nanocrystalline metals and ceramics may be more resistant to radiation damage than their coarse-grained counterparts. The objective of this project look at the effect of microstructure on radiation damage and mechanical behavior in these materials. The approach to be taken was state-of-the-art, large-scale atomic-level simulation. This systematic simulation program of the effects of irradiation on the structure and mechanical properties of polycrystalline Ti and UO2 identified radiation damage mechanisms. Moreover, it will provided important insights into behavior that can be expected in nanocrystalline microstructures and, by extension, nanocomposites. The fundamental insights from this work can be expected to help in the design microstructures that are less susceptible to radiation damage and thermomechanical degradation.

Fundamentals of phosphors

CERN Document Server

Yen, William M; Yamamoto, Hajime

2006-01-01

Drawing from the second edition of the best-selling Handbook of Phosphors, Fundamentals of Phosphors covers the principles and mechanisms of luminescence in detail and surveys the primary phosphor materials as well as their optical properties. The book addresses cutting-edge developments in phosphor science and technology including oxynitride phosphors and the impact of lanthanide level location on phosphor performance.Beginning with an explanation of the physics underlying luminescence mechanisms in solids, the book goes on to interpret various luminescence phenomena in inorganic and organic materials. This includes the interpretation of the luminescence of recently developed low-dimensional systems, such as quantum wells and dots. The book also discusses the excitation mechanisms by cathode-ray and ionizing radiation and by electric fields to produce electroluminescence. The book classifies phosphor materials according to the type of luminescence centers employed or the class of host materials used and inte...

Brake Fundamentals. Automotive Articulation Project.

Science.gov (United States)

Cunningham, Larry; And Others

Designed for secondary and postsecondary auto mechanics programs, this curriculum guide contains learning exercises in seven areas: (1) brake fundamentals; (2) brake lines, fluid, and hoses; (3) drum brakes; (4) disc brake system and service; (5) master cylinder, power boost, and control valves; (6) parking brakes; and (7) trouble shooting. Each…

What is Fundamental?

CERN Multimedia

2004-01-01

Discussing what is fundamental in a variety of fields, biologist Richard Dawkins, physicist Gerardus 't Hooft, and mathematician Alain Connes spoke to a packed Main Auditorium at CERN 15 October. Dawkins, Professor of the Public Understanding of Science at Oxford University, explained simply the logic behind Darwinian natural selection, and how it would seem to apply anywhere in the universe that had the right conditions. 't Hooft, winner of the 1999 Physics Nobel Prize, outlined some of the main problems in physics today, and said he thinks physics is so fundamental that even alien scientists from another planet would likely come up with the same basic principles, such as relativity and quantum mechanics. Connes, winner of the 1982 Fields Medal (often called the Nobel Prize of Mathematics), explained how physics is different from mathematics, which he described as a "factory for concepts," unfettered by connection to the physical world. On 16 October, anthropologist Sharon Traweek shared anecdotes from her ...

Fundamental mechanisms in flue-gas conditioning

Energy Technology Data Exchange (ETDEWEB)

Dahlin, R.S.; Vann Bush, P.; Snyder, T.R.

1992-01-09

The overall goal of this research project is to formulate a mathematical model of flue gas conditioning. This model will be based on an understanding of why ash properties, such as cohesivity and resistivity, are changed by conditioning. Such a model could serve as a component of the performance models of particulate control devices where flue gas conditioning is used. There are two specific objectives of this research project, which divide the planned research into two main parts. One part of the project is designed to determine how ash particles are modified by interactions with sorbent injection processes and to describe the mechanisms by which these interactions affect fine particle collection. The objective of the other part of the project is to identify the mechanisms by which conditioning agents, including chemically active compounds, modify the key properties of fine fly ash particles.

A trajectory description of quantum processes. I. Fundamentals. A Bohmian perspective

International Nuclear Information System (INIS)

Sanz, Angel S.; Miret-Artes, Salvador

2012-01-01

Offers a thorough introduction to, and treatment of, trajectory-based quantum-mechanical calculations. Presents the fundamentals of Bohmian mechanics. Useful for a wide range of scattering problems, as described in Vol. 2. Trajectory-based formalisms are an intuitively appealing way of describing quantum processes because they allow the use of ''classical'' concepts. Beginning at an introductory level suitable for students, this two-volume monograph presents (1) the fundamentals and (2) the applications of the trajectory description of basic quantum processes. This first volume is focussed on the classical and quantum background necessary to understand the fundamentals of Bohmian mechanics, which can be considered the main topic of this work. Extensions of the formalism to the fields of open quantum systems and to optics are also proposed and discussed.

A trajectory description of quantum processes. I. Fundamentals. A Bohmian perspective

Energy Technology Data Exchange (ETDEWEB)

Sanz, Angel S.; Miret-Artes, Salvador [Consejo Superior de Investigaciones Cientificas, Madrid (Spain). Inst. de Fisica Fundamental

2012-11-01

Offers a thorough introduction to, and treatment of, trajectory-based quantum-mechanical calculations. Presents the fundamentals of Bohmian mechanics. Useful for a wide range of scattering problems, as described in Vol. 2. Trajectory-based formalisms are an intuitively appealing way of describing quantum processes because they allow the use of ''classical'' concepts. Beginning at an introductory level suitable for students, this two-volume monograph presents (1) the fundamentals and (2) the applications of the trajectory description of basic quantum processes. This first volume is focussed on the classical and quantum background necessary to understand the fundamentals of Bohmian mechanics, which can be considered the main topic of this work. Extensions of the formalism to the fields of open quantum systems and to optics are also proposed and discussed.

Fundamental Concepts in Biophysics Volume 1

CERN Document Server

Jue, Thomas

2009-01-01

HANDBOOK OF MODERN BIOPHYSICS Series Editor Thomas Jue, PhD Handbook of Modern Biophysics brings current biophysics topics into focus, so that biology, medical, engineering, mathematics, and physical-science students or researchers can learn fundamental concepts and the application of new techniques in addressing biomedical challenges. Chapters explicate the conceptual framework of the physics formalism and illustrate the biomedical applications. With the addition of problem sets, guides to further study, and references, the interested reader can continue to explore independently the ideas presented. Volume I: Fundamental Concepts in Biophysics Editor Thomas Jue, PhD In Fundamental Concepts in Biophysics, prominent professors have established a foundation for the study of biophysics related to the following topics: Mathematical Methods in Biophysics Quantum Mechanics Basic to Biophysical Methods Computational Modeling of Receptor–Ligand Binding and Cellular Signaling Processes Fluorescence Spectroscopy Elec...

Using fundamental equations to describe basic phenomena

DEFF Research Database (Denmark)

Jakobsen, Arne; Rasmussen, Bjarne D.

1999-01-01

When the fundamental thermodynamic balance equations (mass, energy, and momentum) are used to describe the processes in a simple refrigeration system, then one finds that the resulting equation system will have a degree of freedom equal to one. Further investigations reveal that it is the equatio...

Fundamental ecology is fundamental.

Science.gov (United States)

Courchamp, Franck; Dunne, Jennifer A; Le Maho, Yvon; May, Robert M; Thébaud, Christophe; Hochberg, Michael E

2015-01-01

The primary reasons for conducting fundamental research are satisfying curiosity, acquiring knowledge, and achieving understanding. Here we develop why we believe it is essential to promote basic ecological research, despite increased impetus for ecologists to conduct and present their research in the light of potential applications. This includes the understanding of our environment, for intellectual, economical, social, and political reasons, and as a major source of innovation. We contend that we should focus less on short-term, objective-driven research and more on creativity and exploratory analyses, quantitatively estimate the benefits of fundamental research for society, and better explain the nature and importance of fundamental ecology to students, politicians, decision makers, and the general public. Our perspective and underlying arguments should also apply to evolutionary biology and to many of the other biological and physical sciences. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Quantum Mechanics of Fundamental Systems: The Quest for Beauty and Simplicity

CERN Document Server

Zanelli, Jorge

2009-01-01

A collection of contributed papers by former collaborators and colleagues of the author. It includes such topics as, General Relativity, Quantum Gravity, String Theory; from mathematical structures underlying the fundamental interactions, to cosmological scenarios describing the universe at its birth

M(atrix) theory: matrix quantum mechanics as a fundamental theory

International Nuclear Information System (INIS)

Taylor, Washington

2001-01-01

This article reviews the matrix model of M theory. M theory is an 11-dimensional quantum theory of gravity that is believed to underlie all superstring theories. M theory is currently the most plausible candidate for a theory of fundamental physics which reconciles gravity and quantum field theory in a realistic fashion. Evidence for M theory is still only circumstantial -- no complete background-independent formulation of the theory exists as yet. Matrix theory was first developed as a regularized theory of a supersymmetric quantum membrane. More recently, it has appeared in a different guise as the discrete light-cone quantization of M theory in flat space. These two approaches to matrix theory are described in detail and compared. It is shown that matrix theory is a well-defined quantum theory that reduces to a supersymmetric theory of gravity at low energies. Although its fundamental degrees of freedom are essentially pointlike, higher-dimensional fluctuating objects (branes) arise through the non-Abelian structure of the matrix degrees of freedom. The problem of formulating matrix theory in a general space-time background is discussed, and the connections between matrix theory and other related models are reviewed

Fundamental mechanisms and reactions in non-catalytic subcritical hydrothermal processes: A review.

Science.gov (United States)

Yousefifar, Azadeh; Baroutian, Saeid; Farid, Mohammed M; Gapes, Daniel J; Young, Brent R

2017-10-15

The management and disposal of solid waste is of increasing concern across the globe. Hydrothermal processing of sludge has been suggested as a promising solution to deal with the considerable amounts of sludge produced worldwide. Such a process not only degrades organic compounds and reduces waste volume, but also provides an opportunity to recover valuable substances. Hydrothermal processing comprises two main sub-processes: wet oxidation (WO) and thermal hydrolysis (TH), in which the formation of various free radicals results in the production of different intermediates. Volatile fatty acids (VFAs), especially acetic acid, are usually the main intermediates which remain as a by-product of the process. This paper aims to review the fundamental mechanism for hydrothermal processing of sludge, and the formation of different free radicals and intermediates therein. In addition, the proposed kinetic models for the two processes (WO and TH) from the literature are reviewed and the advantages and disadvantages of each model are outlined. The effect of mass transfer as a critical component of the design and development of the processes, which has been neglected in most of these proposed models, is also reviewed, and the effect of influencing parameters on the processes' controlling step (reaction or mass transfer) is discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

The fundamental role of mechanical properties in the progression of cancer disease and inflammation

International Nuclear Information System (INIS)

Mierke, Claudia Tanja

2014-01-01

The role of mechanical properties in cancer disease and inflammation is still underinvestigated and even ignored in many oncological and immunological reviews. In particular, eight classical hallmarks of cancer have been proposed, but they still ignore the mechanics behind the processes that facilitate cancer progression. To define the malignant transformation of neoplasms and finally reveal the functional pathway that enables cancer cells to promote cancer progression, these classical hallmarks of cancer require the inclusion of specific mechanical properties of cancer cells and their microenvironment such as the extracellular matrix as well as embedded cells such as fibroblasts, macrophages or endothelial cells. Thus, this review will present current cancer research from a biophysical point of view and will therefore focus on novel physical aspects and biophysical methods to investigate the aggressiveness of cancer cells and the process of inflammation. As cancer or immune cells are embedded in a certain microenvironment such as the extracellular matrix, the mechanical properties of this microenvironment cannot be neglected, and alterations of the microenvironment may have an impact on the mechanical properties of the cancer or immune cells. Here, it is highlighted how biophysical approaches, both experimental and theoretical, have an impact on the classical hallmarks of cancer and inflammation. It is even pointed out how these biophysical approaches contribute to the understanding of the regulation of cancer disease and inflammatory responses after tissue injury through physical microenvironmental property sensing mechanisms. The recognized physical signals are transduced into biochemical signaling events that guide cellular responses, such as malignant tumor progression, after the transition of cancer cells from an epithelial to a mesenchymal phenotype or an inflammatory response due to tissue injury. Moreover, cell adaptation to mechanical alterations, in

The fundamental role of mechanical properties in the progression of cancer disease and inflammation

Science.gov (United States)

Mierke, Claudia Tanja

2014-07-01

The role of mechanical properties in cancer disease and inflammation is still underinvestigated and even ignored in many oncological and immunological reviews. In particular, eight classical hallmarks of cancer have been proposed, but they still ignore the mechanics behind the processes that facilitate cancer progression. To define the malignant transformation of neoplasms and finally reveal the functional pathway that enables cancer cells to promote cancer progression, these classical hallmarks of cancer require the inclusion of specific mechanical properties of cancer cells and their microenvironment such as the extracellular matrix as well as embedded cells such as fibroblasts, macrophages or endothelial cells. Thus, this review will present current cancer research from a biophysical point of view and will therefore focus on novel physical aspects and biophysical methods to investigate the aggressiveness of cancer cells and the process of inflammation. As cancer or immune cells are embedded in a certain microenvironment such as the extracellular matrix, the mechanical properties of this microenvironment cannot be neglected, and alterations of the microenvironment may have an impact on the mechanical properties of the cancer or immune cells. Here, it is highlighted how biophysical approaches, both experimental and theoretical, have an impact on the classical hallmarks of cancer and inflammation. It is even pointed out how these biophysical approaches contribute to the understanding of the regulation of cancer disease and inflammatory responses after tissue injury through physical microenvironmental property sensing mechanisms. The recognized physical signals are transduced into biochemical signaling events that guide cellular responses, such as malignant tumor progression, after the transition of cancer cells from an epithelial to a mesenchymal phenotype or an inflammatory response due to tissue injury. Moreover, cell adaptation to mechanical alterations, in

The emerging quantum the physics behind quantum mechanics

CERN Document Server

Pena, Luis de la; Valdes-Hernandez, Andrea

2014-01-01

This monograph presents the latest findings from a long-term research project intended to identify the physics behind Quantum Mechanics. A fundamental theory for quantum mechanics is constructed from first physical principles, revealing quantization as an emergent phenomenon arising from a deeper stochastic process. As such, it offers the vibrant community working on the foundations of quantum mechanics an alternative contribution open to discussion. The book starts with a critical summary of the main conceptual problems that still beset quantum mechanics.  The basic consideration is then introduced that any material system is an open system in permanent contact with the random zero-point radiation field, with which it may reach a state of equilibrium. Working from this basis, a comprehensive and self-consistent theoretical framework is then developed. The pillars of the quantum-mechanical formalism are derived, as well as the radiative corrections of nonrelativistic QED, while revealing the underlying physi...

High voltage engineering fundamentals

CERN Document Server

Kuffel, E; Hammond, P

1984-01-01

Provides a comprehensive treatment of high voltage engineering fundamentals at the introductory and intermediate levels. It covers: techniques used for generation and measurement of high direct, alternating and surge voltages for general application in industrial testing and selected special examples found in basic research; analytical and numerical calculation of electrostatic fields in simple practical insulation system; basic ionisation and decay processes in gases and breakdown mechanisms of gaseous, liquid and solid dielectrics; partial discharges and modern discharge detectors; and over

Fundamental gravitational limitations to quantum computing

International Nuclear Information System (INIS)

Gambini, R.; Porto, A.; Pullin, J.

2006-01-01

Lloyd has considered the ultimate limitations the fundamental laws of physics place on quantum computers. He concludes in particular that for an 'ultimate laptop' (a computer of one liter of volume and one kilogram of mass) the maximum number of operations per second is bounded by 10 51 . The limit is derived considering ordinary quantum mechanics. Here we consider additional limits that are placed by quantum gravity ideas, namely the use of a relational notion of time and fundamental gravitational limits that exist on time measurements. We then particularize for the case of an ultimate laptop and show that the maximum number of operations is further constrained to 10 47 per second. (authors)

Mechanism governing heme synthesis reveals a GATA factor/heme circuit that controls differentiation.

Science.gov (United States)

Tanimura, Nobuyuki; Miller, Eli; Igarashi, Kazuhiko; Yang, David; Burstyn, Judith N; Dewey, Colin N; Bresnick, Emery H

2016-02-01

Metal ion-containing macromolecules have fundamental roles in essentially all biological processes throughout the evolutionary tree. For example, iron-containing heme is a cofactor in enzyme catalysis and electron transfer and an essential hemoglobin constituent. To meet the intense demand for hemoglobin assembly in red blood cells, the cell type-specific factor GATA-1 activates transcription of Alas2, encoding the rate-limiting enzyme in heme biosynthesis, 5-aminolevulinic acid synthase-2 (ALAS-2). Using genetic editing to unravel mechanisms governing heme biosynthesis, we discovered a GATA factor- and heme-dependent circuit that establishes the erythroid cell transcriptome. CRISPR/Cas9-mediated ablation of two Alas2 intronic cis elements strongly reduces GATA-1-induced Alas2 transcription, heme biosynthesis, and surprisingly, GATA-1 regulation of other vital constituents of the erythroid cell transcriptome. Bypassing ALAS-2 function in Alas2 cis element-mutant cells by providing its catalytic product 5-aminolevulinic acid rescues heme biosynthesis and the GATA-1-dependent genetic network. Heme amplifies GATA-1 function by downregulating the heme-sensing transcriptional repressor Bach1 and via a Bach1-insensitive mechanism. Through this dual mechanism, heme and a master regulator collaborate to orchestrate a cell type-specific transcriptional program that promotes cellular differentiation. © 2015 The Authors.

Fundamentals of piezoelectric sensorics mechanical, dielectric, and thermodynamical properties of piezoelectric materials

CERN Document Server

Tichý, Jan; Kittinger, Erwin; Prívratská, Jana; Privatska, Jana; Janovec, Vaclav

2010-01-01

This book presents the physics of piezoleletric sensors in a straight-forward and easy-to-grasp way, from the fundamentals of phenomenological crystal physics through more complex concepts, to its explanation of several important piezoelectric materials.

Fundamental of biomedical engineering

CERN Document Server

Sawhney, GS

2007-01-01

About the Book: A well set out textbook explains the fundamentals of biomedical engineering in the areas of biomechanics, biofluid flow, biomaterials, bioinstrumentation and use of computing in biomedical engineering. All these subjects form a basic part of an engineer''s education. The text is admirably suited to meet the needs of the students of mechanical engineering, opting for the elective of Biomedical Engineering. Coverage of bioinstrumentation, biomaterials and computing for biomedical engineers can meet the needs of the students of Electronic & Communication, Electronic & Instrumenta

Radiotherapy and antitumoral immunity. Fundamentals of immunooncology

International Nuclear Information System (INIS)

Klimovich, V.B.

1982-01-01

The fundamental states of immunooncology are described briefly: conception of immunologic inspection, antiblastomic immunologic factors, antigeny of tumor cells and mechanisms of slipping out of immune inspection, problastomic immunologic factors. The conclusion is made that tumor formation and extenstion go on under the action of opposite directed but not mutually exclusive factors of immunologic nature. Growth rate and regression of neoplasm are determined by balance between antiblastomic mechanism activity and activity of problastomic factors and factors of immunoresistant neoplasms

Novel CRISPR/Cas9 gene drive constructs reveal insights into mechanisms of resistance allele formation and drive efficiency in genetically diverse populations.

Directory of Open Access Journals (Sweden)

Jackson Champer

2017-07-01

Full Text Available A functioning gene drive system could fundamentally change our strategies for the control of vector-borne diseases by facilitating rapid dissemination of transgenes that prevent pathogen transmission or reduce vector capacity. CRISPR/Cas9 gene drive promises such a mechanism, which works by converting cells that are heterozygous for the drive construct into homozygotes, thereby enabling super-Mendelian inheritance. Although CRISPR gene drive activity has already been demonstrated, a key obstacle for current systems is their propensity to generate resistance alleles, which cannot be converted to drive alleles. In this study, we developed two CRISPR gene drive constructs based on the nanos and vasa promoters that allowed us to illuminate the different mechanisms by which resistance alleles are formed in the model organism Drosophila melanogaster. We observed resistance allele formation at high rates both prior to fertilization in the germline and post-fertilization in the embryo due to maternally deposited Cas9. Assessment of drive activity in genetically diverse backgrounds further revealed substantial differences in conversion efficiency and resistance rates. Our results demonstrate that the evolution of resistance will likely impose a severe limitation to the effectiveness of current CRISPR gene drive approaches, especially when applied to diverse natural populations.

The relationship between adolescents' physical activity, fundamental movement skills and weight status.

Science.gov (United States)

O' Brien, Wesley; Belton, Sarahjane; Issartel, Johann

2016-01-01

The aim of this study was to determine if a potential relationship among physical activity (PA), fundamental movement skills and weight status exists amongst early adolescent youth. Participants were a sample of 85 students; 54 boys (mean age = 12.94 ± 0.33 years) and 31 girls (mean age = 12.75 ± 0.43 years). Data gathered during physical education class included PA (accelerometry), fundamental movement skills and anthropometric measurements. Standard multiple regression revealed that PA and total fundamental movement skill proficiency scores explained 16.5% (P fundamental movement skills. Results from the current investigation indicate that weight status is an important correlate of fundamental movement skill proficiency during adolescence. Aligned with most recent research, school- and community-based programmes that include developmentally structured learning experiences delivered by specialists can significantly improve fundamental movement skill proficiency in youth.

Study of a Car Body Tilting System Using a Variable Link Mechanism: Fundamental Characteristics of Pendulum Motion and Strategy for Perfect Tilting

Science.gov (United States)

Yoshida, Hidehisa; Nagai, Masao

This paper analyzes the fundamental dynamic characteristics of a tilting railway vehicle using a variable link mechanism for compensating both the lateral acceleration experienced by passengers and the wheel load imbalance between the inner and outer rails. The geometric relations between the center of rotation, the center of gravity, and the positions of all four links of the tilting system are analyzed. Then, equations of the pendulum motions of the railway vehicle body with a four-link mechanism are derived. A theoretically discussion is given on the geometrical shapes employed in the link mechanism that can simultaneously provide zero lateral acceleration and zero wheel load fluctuation. Then, the perfect tilting condition, which is the control target of the feedforward tilting control, is derived from the linear equation of tilting motion.

The fundamental structural factor in determining the glass-forming ability and mechanical behavior in the Cu-Zr metallic glasses

International Nuclear Information System (INIS)

Sha, Z.D.; Feng, Y.P.; Li, Y.

2011-01-01

Research highlights: → A weak but significant hump in trend of the coordinate number and density was observed, respectively. → Our findings indicate our simulation is more accurate to describe the atomic structure of Cu-Zr MGs. The composition-structure-properties correlation was established. → And the effective structural unit for this correlation is the Cu-centered full icosahedra. - Abstract: Using the large-scale atomic/molecular massively parallel simulator, the quantitative composition-structure-properties (including glass-forming ability (GFA) and mechanical behavior) correlations in the Cu-Zr metallic glasses were established. The atomic-level origin of these correlations was tracked down. It was found that the Cu-centered full icosahedron is the microscopic factor that fundamentally influences both GFA and mechanical behavior. Our findings have implications for understanding the nature, forming ability and properties of metallic glasses, and for searching novel metallic glasses with unique functional properties.

Fundamentals of semiconductor devices

CERN Document Server

Lindmayer, Joseph

1965-01-01

Semiconductor properties ; semiconductor junctions or diodes ; transistor fundamentals ; inhomogeneous impurity distributions, drift or graded-base transistors ; high-frequency properties of transistors ; band structure of semiconductors ; high current densities and mechanisms of carrier transport ; transistor transient response and recombination processes ; surfaces, field-effect transistors, and composite junctions ; additional semiconductor characteristics ; additional semiconductor devices and microcircuits ; more metal, insulator, and semiconductor combinations for devices ; four-pole parameters and configuration rotation ; four-poles of combined networks and devices ; equivalent circuits ; the error function and its properties ; Fermi-Dirac statistics ; useful physical constants.

Quantifying Quantum-Mechanical Processes.

Science.gov (United States)

Hsieh, Jen-Hsiang; Chen, Shih-Hsuan; Li, Che-Ming

2017-10-19

The act of describing how a physical process changes a system is the basis for understanding observed phenomena. For quantum-mechanical processes in particular, the affect of processes on quantum states profoundly advances our knowledge of the natural world, from understanding counter-intuitive concepts to the development of wholly quantum-mechanical technology. Here, we show that quantum-mechanical processes can be quantified using a generic classical-process model through which any classical strategies of mimicry can be ruled out. We demonstrate the success of this formalism using fundamental processes postulated in quantum mechanics, the dynamics of open quantum systems, quantum-information processing, the fusion of entangled photon pairs, and the energy transfer in a photosynthetic pigment-protein complex. Since our framework does not depend on any specifics of the states being processed, it reveals a new class of correlations in the hierarchy between entanglement and Einstein-Podolsky-Rosen steering and paves the way for the elaboration of a generic method for quantifying physical processes.

Quantum Mechanics: Fundamentals; Advanced Quantum Mechanics; Mathematical Concepts of Quantum Mechanics

International Nuclear Information System (INIS)

Whitaker, A

2004-01-01

This review is of three books, all published by Springer, all on quantum theory at a level above introductory, but very different in content, style and intended audience. That of Gottfried and Yan is of exceptional interest, historical and otherwise. It is a second edition of Gottfried's well-known book published by Benjamin in 1966. This was written as a text for a graduate quantum mechanics course, and has become one of the most used and respected accounts of quantum theory, at a level mathematically respectable but not rigorous. Topics absent from the first edition but included in the second include the Feynman path integral, seen in 1966 as an imaginative but not very useful formulation of quantum theory. Feynman methods were given only a cursory mention by Gottfried. Other new topics include semiclassical quantum mechanics, motion in a magnetic field, the S matrix and inelastic collisions, radiation and scattering of light, identical particle systems and the Dirac equation. A topic that was all but totally neglected in 1966, but which has flourished increasingly since, is that of the foundations of quantum theory. To commence with general discussion of the new book, the authors recognise that the graduate student of today almost certainly has substantial experience of wave mechanics, and is probably familiar with the Dirac formalism. The new edition has been almost entirely rewritten; even at the level of basic text, it is difficult to trace sentences or paragraphs that have moved unscathed from one edition to the next. As well as the new topics, many of the old ones are discussed in much greater depth, and the general organisation is entirely different. As compared with the steady rise in level of the 1966 edition, the level of this book is fairly consistent throughout, and from the perspective of a beginning graduate student, I would estimate, a little tough. To sum up, Gottfried and Yan's book contains a vast amount of knowledge and understanding. The

A new fundamental type of conformational isomerism

Science.gov (United States)

Canfield, Peter J.; Blake, Iain M.; Cai, Zheng-Li; Luck, Ian J.; Krausz, Elmars; Kobayashi, Rika; Reimers, Jeffrey R.; Crossley, Maxwell J.

2018-06-01

Isomerism is a fundamental chemical concept, reflecting the fact that the arrangement of atoms in a molecular entity has a profound influence on its chemical and physical properties. Here we describe a previously unclassified fundamental form of conformational isomerism through four resolved stereoisomers of a transoid (BF)O(BF)-quinoxalinoporphyrin. These comprise two pairs of enantiomers that manifest structural relationships not describable within existing IUPAC nomenclature and terminology. They undergo thermal diastereomeric interconversion over a barrier of 104 ± 2 kJ mol-1, which we term `akamptisomerization'. Feasible interconversion processes between conceivable synthesis products and reaction intermediates were mapped out by density functional theory calculations, identifying bond-angle inversion (BAI) at a singly bonded atom as the reaction mechanism. We also introduce the necessary BAI stereodescriptors parvo and amplo. Based on an extended polytope formalism of molecular structure and stereoisomerization, BAI-driven akamptisomerization is shown to be the final fundamental type of conformational isomerization.

Amorphous Phase Mediated Crystallization: Fundamentals of Biomineralization

Directory of Open Access Journals (Sweden)

Wenjing Jin

2018-01-01

Full Text Available Many biomineralization systems start from transient amorphous precursor phases, but the exact crystallization pathways and mechanisms remain largely unknown. The study of a well-defined biomimetic crystallization system is key for elucidating the possible mechanisms of biomineralization and monitoring the detailed crystallization pathways. In this review, we focus on amorphous phase mediated crystallization (APMC pathways and their crystallization mechanisms in bio- and biomimetic-mineralization systems. The fundamental questions of biomineralization as well as the advantages and limitations of biomimetic model systems are discussed. This review could provide a full landscape of APMC systems for biomineralization and inspire new experiments aimed at some unresolved issues for understanding biomineralization.

Review: The fundamental mechanism of aqueous contaminant ...

African Journals Online (AJOL)

Contaminant co-precipitation with continuously generated and transformed iron corrosion products has received relatively little attention in comparison to other possible removal mechanisms (adsorption, oxidation, precipitation) in Fe0/H2O systems at near neutral pH values. A primary reason for this is that the use of ...

Fundamental Design Principles for Transcription-Factor-Based Metabolite Biosensors.

Science.gov (United States)

Mannan, Ahmad A; Liu, Di; Zhang, Fuzhong; Oyarzún, Diego A

2017-10-20

Metabolite biosensors are central to current efforts toward precision engineering of metabolism. Although most research has focused on building new biosensors, their tunability remains poorly understood and is fundamental for their broad applicability. Here we asked how genetic modifications shape the dose-response curve of biosensors based on metabolite-responsive transcription factors. Using the lac system in Escherichia coli as a model system, we built promoter libraries with variable operator sites that reveal interdependencies between biosensor dynamic range and response threshold. We developed a phenomenological theory to quantify such design constraints in biosensors with various architectures and tunable parameters. Our theory reveals a maximal achievable dynamic range and exposes tunable parameters for orthogonal control of dynamic range and response threshold. Our work sheds light on fundamental limits of synthetic biology designs and provides quantitative guidelines for biosensor design in applications such as dynamic pathway control, strain optimization, and real-time monitoring of metabolism.

Coherence degree of the fundamental Bessel-Gaussian beam in turbulent atmosphere

Science.gov (United States)

Lukin, Igor P.

2017-11-01

In this article the coherence of a fundamental Bessel-Gaussian optical beam in turbulent atmosphere is analyzed. The problem analysis is based on the solution of the equation for the transverse second-order mutual coherence function of a fundamental Bessel-Gaussian optical beam of optical radiation. The behavior of a coherence degree of a fundamental Bessel-Gaussian optical beam depending on parameters of an optical beam and characteristics of turbulent atmosphere is examined. It was revealed that at low levels of fluctuations in turbulent atmosphere the coherence degree of a fundamental Bessel-Gaussian optical beam has the characteristic oscillating appearance. At high levels of fluctuations in turbulent atmosphere the coherence degree of a fundamental Bessel-Gaussian optical beam is described by an one-scale decreasing curve which in process of increase of level of fluctuations on a line of formation of a laser beam becomes closer to the same characteristic of a spherical optical wave.

Direct observation of TALE protein dynamics reveals a two-state search mechanism.

Science.gov (United States)

Cuculis, Luke; Abil, Zhanar; Zhao, Huimin; Schroeder, Charles M

2015-06-01

Transcription activator-like effector (TALE) proteins are a class of programmable DNA-binding proteins for which the fundamental mechanisms governing the search process are not fully understood. Here we use single-molecule techniques to directly observe TALE search dynamics along DNA templates. We find that TALE proteins are capable of rapid diffusion along DNA using a combination of sliding and hopping behaviour, which suggests that the TALE search process is governed in part by facilitated diffusion. We also observe that TALE proteins exhibit two distinct modes of action during the search process-a search state and a recognition state-facilitated by different subdomains in monomeric TALE proteins. Using TALE truncation mutants, we further demonstrate that the N-terminal region of TALEs is required for the initial non-specific binding and subsequent rapid search along DNA, whereas the central repeat domain is required for transitioning into the site-specific recognition state.

Relativities of fundamentality

Science.gov (United States)

McKenzie, Kerry

2017-08-01

S-dualities have been held to have radical implications for our metaphysics of fundamentality. In particular, it has been claimed that they make the fundamentality status of a physical object theory-relative in an important new way. But what physicists have had to say on the issue has not been clear or consistent, and in particular seems to be ambiguous between whether S-dualities demand an anti-realist interpretation of fundamentality talk or merely a revised realism. This paper is an attempt to bring some clarity to the matter. After showing that even antecedently familiar fundamentality claims are true only relative to a raft of metaphysical, physical, and mathematical assumptions, I argue that the relativity of fundamentality inherent in S-duality nevertheless represents something new, and that part of the reason for this is that it has both realist and anti-realist implications for fundamentality talk. I close by discussing the broader significance that S-dualities have for structuralist metaphysics and for fundamentality metaphysics more generally.

Entanglement, information, and the interpretation of quantum mechanics

International Nuclear Information System (INIS)

Jaeger, Gregg

2009-01-01

This book explores the nature of quantum entanglement and quantum information and their role in the quantum world. Their relations to a number of key experiments and thought experiments in the history of quantum physics are considered, as is a range of interpretations of quantum mechanics that have been put forward as a means of understanding the fundamental nature of microphysics - the traditionally accepted domain of quantum mechanics - and in some cases, the universe as a whole. In this way, the book reveals the deep significance of entanglement and quantum information for our understanding of the physical world. (orig.)

Submillisecond Elastic Recoil Reveals Molecular Origins of Fibrin Fiber Mechanics

Science.gov (United States)

Hudson, Nathan E.; Ding, Feng; Bucay, Igal; O’Brien, E. Timothy; Gorkun, Oleg V.; Superfine, Richard; Lord, Susan T.; Dokholyan, Nikolay V.; Falvo, Michael R.

2013-01-01

Fibrin fibers form the structural scaffold of blood clots. Thus, their mechanical properties are of central importance to understanding hemostasis and thrombotic disease. Recent studies have revealed that fibrin fibers are elastomeric despite their high degree of molecular ordering. These results have inspired a variety of molecular models for fibrin’s elasticity, ranging from reversible protein unfolding to rubber-like elasticity. An important property that has not been explored is the timescale of elastic recoil, a parameter that is critical for fibrin’s mechanical function and places a temporal constraint on molecular models of fiber elasticity. Using high-frame-rate imaging and atomic force microscopy-based nanomanipulation, we measured the recoil dynamics of individual fibrin fibers and found that the recoil was orders of magnitude faster than anticipated from models involving protein refolding. We also performed steered discrete molecular-dynamics simulations to investigate the molecular origins of the observed recoil. Our results point to the unstructured αC regions of the otherwise structured fibrin molecule as being responsible for the elastic recoil of the fibers. PMID:23790375

Fundamentals of Structural Engineering

CERN Document Server

Connor, Jerome J

2013-01-01

Fundamentals of Structural Engineering provides a balanced, seamless treatment of both classic, analytic methods and contemporary, computer-based techniques for conceptualizing and designing a structure. The book’s principle goal is to foster an intuitive understanding of structural behavior based on problem solving experience for students of civil engineering and architecture who have been exposed to the basic concepts of engineering mechanics and mechanics of materials. Making it distinct from many other undergraduate textbooks, the authors of this text recognize the notion that engineers reason about behavior using simple models and intuition they acquire through problem solving. The approach adopted in this text develops this type of intuition  by presenting extensive, realistic problems and case studies together with computer simulation, which allows rapid exploration of  how a structure responds to changes in geometry and physical parameters. This book also: Emphasizes problem-based understanding of...

Fundamental Studies on the Mechanical Behavior and Fracture Characteristics of Metal-Ceramic Interfaces

National Research Council Canada - National Science Library

Mukai, K

1995-01-01

.... There is need for a fundamental level of understanding of the strength characteristics and the origin of failure of the interface since it is the means by which load is transferred from the matrix to reinforcement...

From fundamental fields to constituent quarks and nucleon form factors?

International Nuclear Information System (INIS)

Coester, F.

1991-01-01

Constituent-quark models formulated in the frame work of nonrelativistic quantum mechanics have been successful in accounting for the mass spectra of mesons and baryons. Applications to elastic electron scattering require relativistic dynamics. Relativistic quantum mechanics of constituent quarks can be formulated by constructing a suitable unitary representation of the Poincare group on the three-quark Hilbert space. The mass and spin operators of this representation specify the relativistic model dynamics. The dynamics of fundamental quark fields, on the other hand, is specified by a Euclidean functional integral. In this paper, the author shows how the dynamics of the fundamental fields can be related in principle to the Hamiltonian dynamics of quark particles through the properties of the Wightman functions

A Au82Si18 liquid metal field-ion emitter for the production of Si ions: fundamental properties and mechanisms

International Nuclear Information System (INIS)

Bischoff, L.; Mair, G.L.R.; Aidinis, C.J.; Londos, C.A.; Akhmadaliev, C.; Ganetsos, Th.

2004-01-01

Focused silicon beams are useful for direct write applications, e.g., lithography on silicon without the undesirable effect of substrate contamination. However, since pure silicon is not amenable to liquid metal ion source (LMIS) manufacture, a suitable alloy containing silicon has to be produced. This paper covers almost all fundamental aspects of a Au 82 Si 18 eutectic, including the most detailed beam mass spectra reported to date of a AuSi source. A finding worthy of note in this investigation, manifested in the behaviour of the ion extraction voltage with temperature, is the abnormal behaviour of the surface tension coefficient of the alloy with temperature. An important deduction from this work, however, concerns the mechanisms responsible for the creation of doubly charged ions: reasons of self-consistency indicate that while Si 2+ is directly field evaporated, Au 2+ must form by the post-ionization of Au + . Finally, two different mechanisms seem to co-exist, as far as the production of cluster ions is concerned. While for cluster ions containing only a few atoms some sort of surface field-ionization mechanism might be responsible for their creation, for larger clusters, a droplet break-up mechanism, possibly by ion capture, seems very likely

In search for the unified theory of fundamental interactions

International Nuclear Information System (INIS)

Ansel'm, A.A.

1980-01-01

The problem of developing the unified theory of fundamental interactions is considered in a popular form. The fundamental interactions include interactions between really elementary particles (quarks and leptons) which are performed by strong, weak, electromagnetic and gravitational forces. The unified theory is based on the requirement of ''Local symmetry''. The problem on invariance of strong interaction theory to local isotopic transformation was proposed for the first time by Yang and Mills, who introduced fields, called compensating (they compensate additional members in the theory equations, appearing during local transformations) Quanta of these fields (calibrating bosons) are massless particles with a spin, equal to one. The bosons should have the mass different from zero in order to be the carriers of real strong and weak interactions. At present there exist two mechanisms, due to which the mentioned controdiction can be overcome. One of these mechanisms - spontaneous symmetry distortion, the other mechanism - ''non-escape'', or ''captivity'' of the particles. The main ideas of building the realistic model of strong interaction are briefly presented

Variational principles of continuum mechanics. Vol. 1. Fundamentals

Energy Technology Data Exchange (ETDEWEB)

Berdichevsky, Victor L. [Wayne State Univ., Detroit, MI (United States). Dept. of Mechanical Engineering

2009-07-01

The book reviews the two features of the variational approach: its use as a universal tool to describe physical phenomena and as a source for qualitative and quantitative methods of studying particular problems. Berdichevsky's work differs from other books on the subject in focusing mostly on the physical origin of variational principles as well as establishing their interrelations. For example, the Gibbs principles appear as a consequence of the Einstein formula for thermodynamic fluctuations rather than as the first principles of the theory of thermodynamic equilibrium. Mathematical issues are considered as long as they shed light on the physical outcomes and/or provide a useful technique for the direct study of variational problems. In addition, a thorough account of variational principles discovered in various branches of continuum mechanics is given. In this book, the first volume, the author covers the variational principles for systems with a finite number of degrees of freedom; the variational principles of thermodynamics; the basics of continuum mechanics; the variational principles for classical models of continuum mechanics, such as elastic and plastic bodies, and ideal and viscous fluids; and direct methods of calculus of variations. (orig.)

Free electron laser and fundamental physics

Science.gov (United States)

Dattoli, Giuseppe; Nguyen, Federico

2018-03-01

This review paper is devoted to the understanding of free-electron lasers (FEL) as devices for fundamental physics (FP) studies. After clarifying what FP stands for, we select some aspects of the FEL physics which can be viewed as fundamental. Furthermore, we discuss the perspective uses of the FEL in FP experiments. Regarding the FP aspects of the FEL, we analyze the quantum electrodynamics (QED) nature of the underlying laser mechanism. We look for the truly quantum signature in a process whose phenomenology is dominated by classical effects. As to the use of FEL as a tool for FP experiments we discuss the realization of a device dedicated to the study of non-linear effects in QED such as photon-photon scattering and shining-through-the-wall experiments planned to search for dark matter candidates like axions.

Macroscopic fundamental strings in cosmology

Energy Technology Data Exchange (ETDEWEB)

Aharonov, Y; Englert, F; Orloff, J

1987-12-24

We show that, when D greater than or equal to 4, theories of closed strings of closed strings in D, non-compact space-time dimensions exhibit a phase transition. The high-temperature phase is characterized by a condensate of arbitrarily long strings with Hausdorff dimension two (area filling curves). We suggest that this stringy phase is the ancestor of the adiabatic era. Fundamental strings could then both drive the inflation and seed, in a way reminiscent of the cosmic string mechanism, the large structures in the universe.

Fundamental Research on Percussion Drilling: Improved rock mechanics analysis, advanced simulation technology, and full-scale laboratory investigations

Energy Technology Data Exchange (ETDEWEB)

Michael S. Bruno

2005-12-31

This report summarizes the research efforts on the DOE supported research project Percussion Drilling (DE-FC26-03NT41999), which is to significantly advance the fundamental understandings of the physical mechanisms involved in combined percussion and rotary drilling, and thereby facilitate more efficient and lower cost drilling and exploration of hard-rock reservoirs. The project has been divided into multiple tasks: literature reviews, analytical and numerical modeling, full scale laboratory testing and model validation, and final report delivery. Literature reviews document the history, pros and cons, and rock failure physics of percussion drilling in oil and gas industries. Based on the current understandings, a conceptual drilling model is proposed for modeling efforts. Both analytical and numerical approaches are deployed to investigate drilling processes such as drillbit penetration with compression, rotation and percussion, rock response with stress propagation, damage accumulation and failure, and debris transportation inside the annulus after disintegrated from rock. For rock mechanics modeling, a dynamic numerical tool has been developed to describe rock damage and failure, including rock crushing by compressive bit load, rock fracturing by both shearing and tensile forces, and rock weakening by repetitive compression-tension loading. Besides multiple failure criteria, the tool also includes a damping algorithm to dissipate oscillation energy and a fatigue/damage algorithm to update rock properties during each impact. From the model, Rate of Penetration (ROP) and rock failure history can be estimated. For cuttings transport in annulus, a 3D numerical particle flowing model has been developed with aid of analytical approaches. The tool can simulate cuttings movement at particle scale under laminar or turbulent fluid flow conditions and evaluate the efficiency of cutting removal. To calibrate the modeling efforts, a series of full-scale fluid hammer

Equilibrium statistical mechanics

CERN Document Server

Mayer, J E

1968-01-01

The International Encyclopedia of Physical Chemistry and Chemical Physics, Volume 1: Equilibrium Statistical Mechanics covers the fundamental principles and the development of theoretical aspects of equilibrium statistical mechanics. Statistical mechanical is the study of the connection between the macroscopic behavior of bulk matter and the microscopic properties of its constituent atoms and molecules. This book contains eight chapters, and begins with a presentation of the master equation used for the calculation of the fundamental thermodynamic functions. The succeeding chapters highlight t

Fundamental aspects of quantum theory

International Nuclear Information System (INIS)

Gorini, V.; Frigerio, A.

1986-01-01

This book presents information on the following topics: general problems and crucial experiments; the classical behavior of measuring instruments; quantum interference effect for two atoms radiating a single photon; quantization and stochastic processes; quantum Markov processes driven by Bose noise; chaotic behavior in quantum mechanics; quantum ergodicity and chaos; microscopic and macroscopic levels of description; fundamental properties of the ground state of atoms and molecules; n-level systems interacting with Bosons - semiclassical limits; general aspects of gauge theories; adiabatic phase shifts for neutrons and photons; the spins of cyons and dyons; round-table discussion the the Aharonov-Bohm effect; gravity in quantum mechanics; the gravitational phase transition; anomalies and their cancellation; a new gauge without any ghost for Yang-Mills Theory; and energy density and roughening in the 3-D Ising ferromagnet

Sociocultural Mechanisms of Intergenerational Values and Mindset Translation in Modern Family Development and Generational Change

Science.gov (United States)

Nemova, Olga A.; Retivina, Veronika V.; Kutepova, Lubov I.; Vinnikova, Irina S.; Kuznetsova, Ekaterina A.

2016-01-01

The paper considers the issue of functioning of the mechanism of formation and translation of values of labor in family. Fundamental labor values and main channels of their distribution are revealed based on empiric material. Family influence on motivation of today's Russian youth's labor behavior was determined. An intergenerational comparative…

Submillisecond elastic recoil reveals molecular origins of fibrin fiber mechanics.

Science.gov (United States)

Hudson, Nathan E; Ding, Feng; Bucay, Igal; O'Brien, E Timothy; Gorkun, Oleg V; Superfine, Richard; Lord, Susan T; Dokholyan, Nikolay V; Falvo, Michael R

2013-06-18

Fibrin fibers form the structural scaffold of blood clots. Thus, their mechanical properties are of central importance to understanding hemostasis and thrombotic disease. Recent studies have revealed that fibrin fibers are elastomeric despite their high degree of molecular ordering. These results have inspired a variety of molecular models for fibrin's elasticity, ranging from reversible protein unfolding to rubber-like elasticity. An important property that has not been explored is the timescale of elastic recoil, a parameter that is critical for fibrin's mechanical function and places a temporal constraint on molecular models of fiber elasticity. Using high-frame-rate imaging and atomic force microscopy-based nanomanipulation, we measured the recoil dynamics of individual fibrin fibers and found that the recoil was orders of magnitude faster than anticipated from models involving protein refolding. We also performed steered discrete molecular-dynamics simulations to investigate the molecular origins of the observed recoil. Our results point to the unstructured αC regions of the otherwise structured fibrin molecule as being responsible for the elastic recoil of the fibers. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Integrative modelling reveals mechanisms linking productivity and plant species richness.

Science.gov (United States)

Grace, James B; Anderson, T Michael; Seabloom, Eric W; Borer, Elizabeth T; Adler, Peter B; Harpole, W Stanley; Hautier, Yann; Hillebrand, Helmut; Lind, Eric M; Pärtel, Meelis; Bakker, Jonathan D; Buckley, Yvonne M; Crawley, Michael J; Damschen, Ellen I; Davies, Kendi F; Fay, Philip A; Firn, Jennifer; Gruner, Daniel S; Hector, Andy; Knops, Johannes M H; MacDougall, Andrew S; Melbourne, Brett A; Morgan, John W; Orrock, John L; Prober, Suzanne M; Smith, Melinda D

2016-01-21

How ecosystem productivity and species richness are interrelated is one of the most debated subjects in the history of ecology. Decades of intensive study have yet to discern the actual mechanisms behind observed global patterns. Here, by integrating the predictions from multiple theories into a single model and using data from 1,126 grassland plots spanning five continents, we detect the clear signals of numerous underlying mechanisms linking productivity and richness. We find that an integrative model has substantially higher explanatory power than traditional bivariate analyses. In addition, the specific results unveil several surprising findings that conflict with classical models. These include the isolation of a strong and consistent enhancement of productivity by richness, an effect in striking contrast with superficial data patterns. Also revealed is a consistent importance of competition across the full range of productivity values, in direct conflict with some (but not all) proposed models. The promotion of local richness by macroecological gradients in climatic favourability, generally seen as a competing hypothesis, is also found to be important in our analysis. The results demonstrate that an integrative modelling approach leads to a major advance in our ability to discern the underlying processes operating in ecological systems.

Ripple formation in unilamellar-supported lipid bilayer revealed by FRAPP.

Science.gov (United States)

Harb, Frédéric; Simon, Anne; Tinland, Bernard

2013-12-01

The mechanisms of formation and conditions of the existence of the ripple phase are fundamental thermodynamic questions with practical implications for medicine and pharmaceuticals. We reveal a new case of ripple formation occurring in unilamellar-supported bilayers in water, which results solely from the bilayer/support interaction, without using lipid mixtures or specific ions. This ripple phase is detected by FRAPP using diffusion coefficient measurements as a function of temperature: a diffusivity plateau is observed. It occurs in the same temperature range where ripple phase existence has been observed using other methods. When AFM experiments are performed in the appropriate temperature range the ripple phase is confirmed.

Fundamentalism and science

Directory of Open Access Journals (Sweden)

Massimo Pigliucci

2006-06-01

Full Text Available The many facets of fundamentalism. There has been much talk about fundamentalism of late. While most people's thought on the topic go to the 9/11 attacks against the United States, or to the ongoing war in Iraq, fundamentalism is affecting science and its relationship to society in a way that may have dire long-term consequences. Of course, religious fundamentalism has always had a history of antagonism with science, and – before the birth of modern science – with philosophy, the age-old vehicle of the human attempt to exercise critical thinking and rationality to solve problems and pursue knowledge. “Fundamentalism” is defined by the Oxford Dictionary of the Social Sciences1 as “A movement that asserts the primacy of religious values in social and political life and calls for a return to a 'fundamental' or pure form of religion.” In its broadest sense, however, fundamentalism is a form of ideological intransigence which is not limited to religion, but includes political positions as well (for example, in the case of some extreme forms of “environmentalism”.

Nano-analytical electron microscopy reveals fundamental insights into human cardiovascular tissue calcification

Science.gov (United States)

Bertazzo, Sergio; Gentleman, Eileen; Cloyd, Kristy L.; Chester, Adrian H.; Yacoub, Magdi H.; Stevens, Molly M.

2013-06-01

The accumulation of calcified material in cardiovascular tissue is thought to involve cytochemical, extracellular matrix and systemic signals; however, its precise composition and nanoscale architecture remain largely unexplored. Using nano-analytical electron microscopy techniques, we examined valves, aortae and coronary arteries from patients with and without calcific cardiovascular disease and detected spherical calcium phosphate particles, regardless of the presence of calcific lesions. We also examined lesions after sectioning with a focused ion beam and found that the spherical particles are composed of highly crystalline hydroxyapatite that crystallographically and structurally differs from bone mineral. Taken together, these data suggest that mineralized spherical particles may play a fundamental role in calcific lesion formation. Their ubiquitous presence in varied cardiovascular tissues and from patients with a spectrum of diseases further suggests that lesion formation may follow a common process. Indeed, applying materials science techniques to ectopic and orthotopic calcification has great potential to lend critical insights into pathophysiological processes underlying calcific cardiovascular disease.

Fundamentals of Agent Perception and Attention Modelling

DEFF Research Database (Denmark)

Peters, Christopher; Castellano, Ginevra; Rehm, Matthias

2011-01-01

Perception and attention mechanisms are of great importance for entities situated within complex dynamic environments. With roles extending greatly beyond passive information services about the external environment, such mechanisms actively prioritise, augment and expedite information to ensure t...... agents can achieve a more substantial connection with their environment for the purposes of reacting, planning, decision making and, ultimately, behaving.......Perception and attention mechanisms are of great importance for entities situated within complex dynamic environments. With roles extending greatly beyond passive information services about the external environment, such mechanisms actively prioritise, augment and expedite information to ensure...... that the potentially relevant is made available so appropriate action can take place. Here, we describe the rationale behind endowing artificial entities, or virtual agents, with real-time perception and attention systems. We cover the fundamentals of designing and building such systems. Once equipped, the resulting...

Endogenous molecular network reveals two mechanisms of heterogeneity within gastric cancer

Science.gov (United States)

Li, Site; Zhu, Xiaomei; Liu, Bingya; Wang, Gaowei; Ao, Ping

2015-01-01

Intratumor heterogeneity is a common phenomenon and impedes cancer therapy and research. Gastric cancer (GC) cells have generally been classified into two heterogeneous cellular phenotypes, the gastric and intestinal types, yet the mechanisms of maintaining two phenotypes and controlling phenotypic transition are largely unknown. A qualitative systematic framework, the endogenous molecular network hypothesis, has recently been proposed to understand cancer genesis and progression. Here, a minimal network corresponding to such framework was found for GC and was quantified via a stochastic nonlinear dynamical system. We then further extended the framework to address the important question of intratumor heterogeneity quantitatively. The working network characterized main known features of normal gastric epithelial and GC cell phenotypes. Our results demonstrated that four positive feedback loops in the network are critical for GC cell phenotypes. Moreover, two mechanisms that contribute to GC cell heterogeneity were identified: particular positive feedback loops are responsible for the maintenance of intestinal and gastric phenotypes; GC cell progression routes that were revealed by the dynamical behaviors of individual key components are heterogeneous. In this work, we constructed an endogenous molecular network of GC that can be expanded in the future and would broaden the known mechanisms of intratumor heterogeneity. PMID:25962957

Fundamental safety principles. Safety fundamentals

International Nuclear Information System (INIS)

2007-01-01

This publication states the fundamental safety objective and ten associated safety principles, and briefly describes their intent and purpose. The fundamental safety objective - to protect people and the environment from harmful effects of ionizing radiation - applies to all circumstances that give rise to radiation risks. The safety principles are applicable, as relevant, throughout the entire lifetime of all facilities and activities - existing and new - utilized for peaceful purposes, and to protective actions to reduce existing radiation risks. They provide the basis for requirements and measures for the protection of people and the environment against radiation risks and for the safety of facilities and activities that give rise to radiation risks, including, in particular, nuclear installations and uses of radiation and radioactive sources, the transport of radioactive material and the management of radioactive waste

Fundamental safety principles. Safety fundamentals

International Nuclear Information System (INIS)

2006-01-01

This publication states the fundamental safety objective and ten associated safety principles, and briefly describes their intent and purpose. The fundamental safety objective - to protect people and the environment from harmful effects of ionizing radiation - applies to all circumstances that give rise to radiation risks. The safety principles are applicable, as relevant, throughout the entire lifetime of all facilities and activities - existing and new - utilized for peaceful purposes, and to protective actions to reduce existing radiation risks. They provide the basis for requirements and measures for the protection of people and the environment against radiation risks and for the safety of facilities and activities that give rise to radiation risks, including, in particular, nuclear installations and uses of radiation and radioactive sources, the transport of radioactive material and the management of radioactive waste

Fundamentals of power integrity for computer platforms and systems

CERN Document Server

DiBene, Joseph T

2014-01-01

An all-encompassing text that focuses on the fundamentals of power integrity Power integrity is the study of power distribution from the source to the load and the system level issues that can occur across it. For computer systems, these issues can range from inside the silicon to across the board and may egress into other parts of the platform, including thermal, EMI, and mechanical. With a focus on computer systems and silicon level power delivery, this book sheds light on the fundamentals of power integrity, utilizing the author's extensive background in the power integrity industry and un

Fundamentals of the mechanics of solids

CERN Document Server

Mariano, Paolo Maria

2015-01-01

This distinctive textbook aims to introduce readers to the basic structures of the mechanics of deformable bodies, with a special emphasis on the description of the elastic behavior of simple materials and structures composed by elastic beams.  The authors take a deductive rather than inductive approach and start from a few first, foundational principles.  A wide selection of exercises, many with hints and solutions, are provided throughout and organized in a way that will allow readers to form a link between abstract mathematical concepts and real-world applications. The text begins with the definition of bodies and deformations, keeping the kinematics of rigid bodies as a special case; the authors also distinguish between material and spatial metrics, defining each one in the pertinent space.  Subsequent chapters cover observers and classes of possible changes; forces, torques, and related balances, which are derived from the invariance under classical changes in observers of the power of the external ...

Escola de ensino fundamental(s em movimento – movimento na escola de ensino fundamental

Directory of Open Access Journals (Sweden)

Reiner Hildebrandt-Stramann

2007-12-01

Full Text Available A escola de ensino fundamental na Alemanha sofreu movimento nos últimos 15 anos, porque, entre outros motivos, entrou movimento nessas escolas. Esse jogo de palavras chama atenção a duas linhas de trabalho que determinam a discussão na atual pedagogia escolar. O presente trabalho revela essas duas perspectivas. Uma das linhas está relacionada ao atual processo de mudança na pedagogia escolar. Essa prediz que a escola de ensino fundamental deve ser um lugar de aprendizagem e de vivência para as crianças. A outra linha tem a ver com o jogo de palavras ancorado a esses processos da pedagogia do movimento, a qual ganha cada vez maiores dimensões. A escola de ensino fundamental deve ser vista sob a perspectiva do movimento e transformada em um lugar de movimento.

Opto-acoustic microscopy reveals adhesion mechanics of single cells

Science.gov (United States)

Abi Ghanem, Maroun; Dehoux, Thomas; Liu, Liwang; Le Saux, Guillaume; Plawinski, Laurent; Durrieu, Marie-Christine; Audoin, Bertrand

2018-01-01

Laser-generated GHz-ultrasonic-based technologies have shown the ability to image single cell adhesion and stiffness simultaneously. Using this new modality, we here demonstrate quantitative indicators to investigate contact mechanics and adhesion processes of the cell. We cultured human cells on a rigid substrate, and we used an inverted pulsed opto-acoustic microscope to generate acoustic pulses containing frequencies up to 100 GHz in the substrate. We map the reflection of the acoustic pulses at the cell-substrate interface to obtain images of the acoustic impedance of the cell, Zc, as well as of the stiffness of the interface, K, with 1 μm lateral resolution. Our results show that the standard deviation ΔZc reveals differences between different cell types arising from the multiplicity of local conformations within the nucleus. From the distribution of K-values within the nuclear region, we extract a mean interfacial stiffness, Km, that quantifies the average contact force in areas of the cell displaying weak bonding. By analogy with classical contact mechanics, we also define the ratio of the real to nominal contact areas, Sr/St. We show that Km can be interpreted as a quantitative indicator of passive contact at metal-cell interfaces, while Sr/St is sensitive to active adhesive processes in the nuclear region. The ability to separate the contributions of passive and active adhesion processes should allow gaining insight into cell-substrate interactions, with important applications in tissue engineering.

Fundamentals of continuum mechanics – classical approaches and new trends

Science.gov (United States)

Altenbach, H.

2018-04-01

Continuum mechanics is a branch of mechanics that deals with the analysis of the mechanical behavior of materials modeled as a continuous manifold. Continuum mechanics models begin mostly by introducing of three-dimensional Euclidean space. The points within this region are defined as material points with prescribed properties. Each material point is characterized by a position vector which is continuous in time. Thus, the body changes in a way which is realistic, globally invertible at all times and orientation-preserving, so that the body cannot intersect itself and as transformations which produce mirror reflections are not possible in nature. For the mathematical formulation of the model it is also assumed to be twice continuously differentiable, so that differential equations describing the motion may be formulated. Finally, the kinematical relations, the balance equations, the constitutive and evolution equations and the boundary and/or initial conditions should be defined. If the physical fields are non-smooth jump conditions must be taken into account. The basic equations of continuum mechanics are presented following a short introduction. Additionally, some examples of solid deformable continua will be discussed within the presentation. Finally, advanced models of continuum mechanics will be introduced. The paper is dedicated to Alexander Manzhirov’s 60th birthday.

Fundamental volatility and stock returns : does fundamental volatility explain stock returns?

OpenAIRE

Selboe, Guner K.; Virdee, Jaspal Singh

2017-01-01

In this thesis, we investigate whether the fundamental uncertainty can explain the crosssection of stock returns. To measure the fundamental uncertainty, we estimate rolling standard deviations and accounting betas of four different fundamentals: revenues, gross profit, earnings and cash flows. The standard deviation and the beta of revenues significantly explain returns in the Fama-Macbeth procedure, but only appears significant among smaller stocks in the portfolio formation ...

Fundamental Electronic Structure Characteristics and Mechanical Behavior of Aerospace Materials

National Research Council Canada - National Science Library

Freeman, Arthur J; Kontsevoi, Oleg Y; Gornostyrev, Yuri N; Medvedeva, Nadezhda I

2008-01-01

To fulfill the great potential of intermetallic alloys for high temperature structural applications, it is essential to understand the mechanisms controlling their mechanical behavior on the microscopic level...

Mechanical seals

CERN Document Server

Mayer, E

1977-01-01

Mechanical Seals, Third Edition is a source of practical information on the design and use of mechanical seals. Topics range from design fundamentals and test rigs to leakage, wear, friction and power, reliability, and special designs. This text is comprised of nine chapters; the first of which gives a general overview of seals, including various types of seals and their applications. Attention then turns to the fundamentals of seal design, with emphasis on six requirements that must be considered: sealing effectiveness, length of life, reliability, power consumption, space requirements, and c

Quantum mechanics

CERN Document Server

Fitzpatrick, Richard

2015-01-01

Quantum mechanics was developed during the first few decades of the twentieth century via a series of inspired guesses made by various physicists, including Planck, Einstein, Bohr, Schroedinger, Heisenberg, Pauli, and Dirac. All these scientists were trying to construct a self-consistent theory of microscopic dynamics that was compatible with experimental observations. The purpose of this book is to present quantum mechanics in a clear, concise, and systematic fashion, starting from the fundamental postulates, and developing the theory in as logical manner as possible. Topics covered in the book include the fundamental postulates of quantum mechanics, angular momentum, time-dependent and time-dependent perturbation theory, scattering theory, identical particles, and relativistic electron theory.

On time variation of fundamental constants in superstring theories

International Nuclear Information System (INIS)

Maeda, K.I.

1988-01-01

Assuming the action from the string theory and taking into account the dynamical freedom of a dilaton and its coupling to matter fluid, the authors show that fundamental 'constants' in string theories are independent of the 'radius' of the internal space. Since the scalar related to the 'constants' is coupled to the 4-dimensional gravity and matter fluid in the same way as in the Jordan-Brans Dicke theory with ω = -1, it must be massive and can get a mass easily through some symmetry breaking mechanism (e.g. the SUSY breaking due to a gluino condensation). Consequently, time variation of fundamental constants is too small to be observed

Liquid-Phase Electrical Discharges: Fundamental Mechanisms and Applications

Science.gov (United States)

Franclemont, Joshua

The increased demand in alternative energy in recent decades has generated significant interest in cleaner fuel sources including hydrogen and syngas (hydrogen and carbon monoxide). Hydrogen and syngas are both primarily produced through the steam reforming of hydrocarbons, specifically natural gas. Although other processes are known, the cheapest source of these fuels is currently through the heating of natural gas in the presence of steam and a catalyst. However, due to the emissions associated with the steam reforming of natural gas and the lack of low cost, efficient, and reliable onboard hydrogen storage technologies for fuel cell powered vehicles, attention has been focused on plasma-assisted reforming of hydrocarbons. Plasma processes can be implemented onboard and are able to directly reform liquid hydrocarbons and alcohols without external heating or catalysts. In addition to hydrogen and syngas, the plasma-assisted reforming of hydrocarbons and alcohols offers other desirable products such as C2 gases (ethane, ethylene, and acetylene), methanol and ethanol. The primary goal of this study is to investigate the fundamental chemical reactions occurring during plasma-assisted reforming of liquid hydrocarbons and alcohols using streamer-like pulsed electrical discharges. Due to the relatively unexplored field of chemical reactions in liquid plasmas, the focus of this study is on elucidating chemical pathways responsible for the formation of hydrogen, syngas, and other products during the direct reforming of liquid methanol, glycerol, and pentane as model species.

Opto-acoustic microscopy reveals adhesion mechanics of single cells.

Science.gov (United States)

Abi Ghanem, Maroun; Dehoux, Thomas; Liu, Liwang; Le Saux, Guillaume; Plawinski, Laurent; Durrieu, Marie-Christine; Audoin, Bertrand

2018-01-01

Laser-generated GHz-ultrasonic-based technologies have shown the ability to image single cell adhesion and stiffness simultaneously. Using this new modality, we here demonstrate quantitative indicators to investigate contact mechanics and adhesion processes of the cell. We cultured human cells on a rigid substrate, and we used an inverted pulsed opto-acoustic microscope to generate acoustic pulses containing frequencies up to 100 GHz in the substrate. We map the reflection of the acoustic pulses at the cell-substrate interface to obtain images of the acoustic impedance of the cell, Z c , as well as of the stiffness of the interface, K, with 1 μm lateral resolution. Our results show that the standard deviation ΔZ c reveals differences between different cell types arising from the multiplicity of local conformations within the nucleus. From the distribution of K-values within the nuclear region, we extract a mean interfacial stiffness, K m , that quantifies the average contact force in areas of the cell displaying weak bonding. By analogy with classical contact mechanics, we also define the ratio of the real to nominal contact areas, S r /S t . We show that K m can be interpreted as a quantitative indicator of passive contact at metal-cell interfaces, while S r /S t is sensitive to active adhesive processes in the nuclear region. The ability to separate the contributions of passive and active adhesion processes should allow gaining insight into cell-substrate interactions, with important applications in tissue engineering.

On the conception of fundamental time asymmetries in physics

Energy Technology Data Exchange (ETDEWEB)

Wohlfarth, Daniel

2013-02-05

The investigation is divided in 7 chapters and aims to argue for the realizability of a new conception of 'fundamental time asymmetries' in physics. After an introduction (chapter 1) in the field of interest, the investigation continues by developing a conception of fundamentality for time asymmetries in chapter 2. Chapter 3 shows that this conception is realized in classical cosmology and chapter 4 demonstrates, by taking in to account the result from chapter 3, that classical electrodynamics is understandable as a time asymmetric theory. Chapter 5 focuses on time asymmetries in quantum cosmology as well as quantum thermodynamics and demonstrates - as in the classical case - that a fundamental time asymmetry is imbedded in those fields. The considerations, contained in chapter 6, are focused on non relativistic quantum mechanics (NRQM). Here the main aim is to demonstrate that NRQM can be understood as a time asymmetric theory - even without using the measurement-process for that purpose. Chapter 7 summarized the main arguments and conclusions.

On the conception of fundamental time asymmetries in physics

International Nuclear Information System (INIS)

Wohlfarth, Daniel

2013-01-01

The investigation is divided in 7 chapters and aims to argue for the realizability of a new conception of 'fundamental time asymmetries' in physics. After an introduction (chapter 1) in the field of interest, the investigation continues by developing a conception of fundamentality for time asymmetries in chapter 2. Chapter 3 shows that this conception is realized in classical cosmology and chapter 4 demonstrates, by taking in to account the result from chapter 3, that classical electrodynamics is understandable as a time asymmetric theory. Chapter 5 focuses on time asymmetries in quantum cosmology as well as quantum thermodynamics and demonstrates - as in the classical case - that a fundamental time asymmetry is imbedded in those fields. The considerations, contained in chapter 6, are focused on non relativistic quantum mechanics (NRQM). Here the main aim is to demonstrate that NRQM can be understood as a time asymmetric theory - even without using the measurement-process for that purpose. Chapter 7 summarized the main arguments and conclusions.

Uncovering the inertia of dislocation motion and negative mechanical response in crystals.

Science.gov (United States)

Tang, Yizhe

2018-01-09

Dislocations are linear defects in crystals and their motion controls crystals' mechanical behavior. The dissipative nature of dislocation propagation is generally accepted although the specific mechanisms are still not fully understood. The inertia, which is undoubtedly the nature of motion for particles with mass, seems much less convincing for configuration propagation. We utilize atomistic simulations in conditions that minimize dissipative effects to enable uncovering of the hidden nature of dislocation motion, in three typical model metals Mg, Cu and Ta. We find that, with less/no dissipation, dislocation motion is under-damped and explicitly inertial at both low and high velocities. The inertia of dislocation motion is intrinsic, and more fundamental than the dissipative nature. The inertia originates from the kinetic energy imparted from strain energy and stored in the moving core. Peculiar negative mechanical response associated with the inertia is also discovered. These findings shed light on the fundamental nature of dislocation motion, reveal the underlying physics, and provide a new physical explanation for phenomena relevant to high-velocity dislocations.

Protecting steel from rusting by rust. The mechanism of rust formation and its control

International Nuclear Information System (INIS)

Kimura, Masao

2008-01-01

Weathering steel, when exposed outdoors for a few years, forms a protective layer resulting in reduction of the corrosion rate. The state of rusts is fundamental for understanding its mechanisms, but the structure and its relationship with the mechanism have not been understood. In this study, a new crystallographic approach was applied to reveal nano-structure of rusts with using of X-ray synchrotron radiation. It has been shown that additional elements alter the corrosion process in its early stage, resulting in formation of protective rusts. (author)

Investigations of fundamental phenomena in quantum mechanics with neutrons

International Nuclear Information System (INIS)

Hasegawa, Yuji

2014-01-01

Neutron interferometer and polarimeter are used for the experimental investigations of quantum mechanical phenomena. Interferometry exhibits clear evidence of quantum-contextuality and polarimetry demonstrates conflicts of a contextual model of quantum mechanics á la Leggett. In these experiments, entanglements are achieved between degrees of freedom in a single-particle: spin, path and energy degrees of freedom are manipulated coherently and entangled. Both experiments manifest the fact that quantum contextuality is valid for phenomena with matter waves with high precision. In addition, another experiment is described which deals with error-disturbance uncertainty relation: we have experimentally tested error-disturbance uncertainty relations, one is derived by Heisenberg and the other by Ozawa. Experimental results confirm the fact that the Heisenberg's uncertainty relation is often violated and that the new relation by Ozawa is always larger than the limit. At last, as an example of a counterfactual phenomenon of quantum mechanics, observation of so-called quantum Cheshire Cat is carried out by using neutron interferometer. Experimental results suggest that pre- and post-selected neutrons travel through one of the arms of the interferometer while their magnetic moment is located in the other arm.

Fundamental trends in fluid-structure interaction

CERN Document Server

Galdi, Giovanni P

2010-01-01

The interaction of a fluid with a solid body is a widespread phenomenon in nature, occurring at different scales and different applied disciplines. Interestingly enough, even though the mathematical theory of the motion of bodies in a liquid is one of the oldest and most classical problems in fluid mechanics, mathematicians have, only very recently, become interested in a systematic study of the basic problems related to fluid-structure interaction, from both analytical and numerical viewpoints. ""Fundamental Trends in Fluid-Structure Interaction"" is a unique collection of important papers wr

Fundamentals of electronics

CERN Document Server

Schubert, Thomas F

2015-01-01

This book, Electronic Devices and Circuit Application, is the first of four books of a larger work, Fundamentals of Electronics. It is comprised of four chapters describing the basic operation of each of the four fundamental building blocks of modern electronics: operational amplifiers, semiconductor diodes, bipolar junction transistors, and field effect transistors. Attention is focused on the reader obtaining a clear understanding of each of the devices when it is operated in equilibrium. Ideas fundamental to the study of electronic circuits are also developed in the book at a basic level to

Fundamentals of gas dynamics

CERN Document Server

Babu, V

2014-01-01

Fundamentals of Gas Dynamics, Second Edition isa comprehensively updated new edition and now includes a chapter on the gas dynamics of steam. It covers the fundamental concepts and governing equations of different flows, and includes end of chapter exercises based on the practical applications. A number of useful tables on the thermodynamic properties of steam are also included.Fundamentals of Gas Dynamics, Second Edition begins with an introduction to compressible and incompressible flows before covering the fundamentals of one dimensional flows and normal shock wav

Effective and fundamental quantum fields at criticality

Energy Technology Data Exchange (ETDEWEB)

Scherer, Michael

2010-10-28

We employ Wetterich's approach to functional renormalization as a suitable method to investigate universal phenomena in non-perturbative quantum field theories both qualitatively and quantitatively. Therefore we derive and investigate flow equations for a class of chiral Yukawa models with and without gauge bosons and reveal fixed-point mechanisms. In four dimensions chiral Yukawa systems serve as toy models for the standard model Higgs sector and show signatures of asymptotically safe fixed points by a balancing of bosonic and fermionic contributions. In the approximations investigated this renders the theory fundamental and solves the triviality problem. Further, we obtain predictions for the Higgs mass and even for the top mass of our toy model. In three dimensions we compute the critical exponents which define new universality classes and provide benchmark values for systems of strongly correlated chiral fermions. In a Yukawa system of non-relativistic two-component fermions a fixed point dominates the renormalization flow giving rise to universality in the BCS-BEC crossover. We push the functional renormalization method to a quantitative level and we compute the critical temperature and the single-particle gap with a considerable precision for the whole crossover. Finally, we provide further evidence for the asymptotic safety scenario in quantum gravity by confirming the existence of an ultraviolet fixed point under inclusion of a curvature-ghost coupling. (orig.)

Effective and fundamental quantum fields at criticality

International Nuclear Information System (INIS)

Scherer, Michael

2010-01-01

We employ Wetterich's approach to functional renormalization as a suitable method to investigate universal phenomena in non-perturbative quantum field theories both qualitatively and quantitatively. Therefore we derive and investigate flow equations for a class of chiral Yukawa models with and without gauge bosons and reveal fixed-point mechanisms. In four dimensions chiral Yukawa systems serve as toy models for the standard model Higgs sector and show signatures of asymptotically safe fixed points by a balancing of bosonic and fermionic contributions. In the approximations investigated this renders the theory fundamental and solves the triviality problem. Further, we obtain predictions for the Higgs mass and even for the top mass of our toy model. In three dimensions we compute the critical exponents which define new universality classes and provide benchmark values for systems of strongly correlated chiral fermions. In a Yukawa system of non-relativistic two-component fermions a fixed point dominates the renormalization flow giving rise to universality in the BCS-BEC crossover. We push the functional renormalization method to a quantitative level and we compute the critical temperature and the single-particle gap with a considerable precision for the whole crossover. Finally, we provide further evidence for the asymptotic safety scenario in quantum gravity by confirming the existence of an ultraviolet fixed point under inclusion of a curvature-ghost coupling. (orig.)

DOE fundamentals handbook: Material science

International Nuclear Information System (INIS)

1993-01-01

This handbook was developed to assist nuclear facility operating contractors in providing operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the structure and properties of metals. This volume contains the following modules: thermal shock (thermal stress, pressurized thermal shock), brittle fracture (mechanism, minimum pressurization-temperature curves, heatup/cooldown rate limits), and plant materials (properties considered when selecting materials, fuel materials, cladding and reflectors, control materials, nuclear reactor core problems, plant material problems, atomic displacement due to irradiation, thermal and displacement spikes due to irradiation, neutron capture effect, radiation effects in organic compounds, reactor use of aluminum)

Phaseolin expression in tobacco chloroplast reveals an autoregulatory mechanism in heterologous protein translation.

Science.gov (United States)

De Marchis, Francesca; Bellucci, Michele; Pompa, Andrea

2016-02-01

Plastid DNA engineering is a well-established research area of plant biotechnology, and plastid transgenes often give high expression levels. However, it is still almost impossible to predict the accumulation rate of heterologous protein in transplastomic plants, and there are many cases of unsuccessful transgene expression. Chloroplasts regulate their proteome at the post-transcriptional level, mainly through translation control. One of the mechanisms to modulate the translation has been described in plant chloroplasts for the chloroplast-encoded subunits of multiprotein complexes, and the autoregulation of the translation initiation of these subunits depends on the availability of their assembly partners [control by epistasy of synthesis (CES)]. In Chlamydomonas reinhardtii, autoregulation of endogenous proteins recruited in the assembly of functional complexes has also been reported. In this study, we revealed a self-regulation mechanism triggered by the accumulation of a soluble recombinant protein, phaseolin, in the stroma of chloroplast-transformed tobacco plants. Immunoblotting experiments showed that phaseolin could avoid this self-regulation mechanism when targeted to the thylakoids in transplastomic plants. To inhibit the thylakoid-targeted phaseolin translation as well, this protein was expressed in the presence of a nuclear version of the phaseolin gene with a transit peptide. Pulse-chase and polysome analysis revealed that phaseolin mRNA translation on plastid ribosomes was repressed due to the accumulation in the stroma of the same soluble polypeptide imported from the cytosol. We suggest that translation autoregulation in chloroplast is not limited to heteromeric protein subunits but also involves at least some of the foreign soluble recombinant proteins, leading to the inhibition of plastome-encoded transgene expression in chloroplast. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Electrodeposition and surface finishing fundamentals and applications

CERN Document Server

Djokic, Stojan

2014-01-01

This volume of Modern Aspects of Electrochemistry has contributions from significant individuals in electrochemistry. This 7 chapter book discusses electrodeposition and the characterization of alloys and composite materials, the mechanistic aspects of lead electrodeposition, electrophoretic deposition of ceramic materials onto metal surfaces and the fundamentals of metal oxides for energy conversion and storage technologies. This volume also has a chapter devoted to the anodization of aluminum, electrochemical aspects of chemical and mechanical polishing, and surface treatments prior to metal

Modeling, Measurements, and Fundamental Database Development for Nonequilibrium Hypersonic Aerothermodynamics

Science.gov (United States)

Bose, Deepak

2012-01-01

The design of entry vehicles requires predictions of aerothermal environment during the hypersonic phase of their flight trajectories. These predictions are made using computational fluid dynamics (CFD) codes that often rely on physics and chemistry models of nonequilibrium processes. The primary processes of interest are gas phase chemistry, internal energy relaxation, electronic excitation, nonequilibrium emission and absorption of radiation, and gas-surface interaction leading to surface recession and catalytic recombination. NASAs Hypersonics Project is advancing the state-of-the-art in modeling of nonequilibrium phenomena by making detailed spectroscopic measurements in shock tube and arcjets, using ab-initio quantum mechanical techniques develop fundamental chemistry and spectroscopic databases, making fundamental measurements of finite-rate gas surface interactions, implementing of detailed mechanisms in the state-of-the-art CFD codes, The development of new models is based on validation with relevant experiments. We will present the latest developments and a roadmap for the technical areas mentioned above

Fractional quantum mechanics

CERN Document Server

Laskin, Nick

2018-01-01

Fractional quantum mechanics is a recently emerged and rapidly developing field of quantum physics. This is the first monograph on fundamentals and physical applications of fractional quantum mechanics, written by its founder. The fractional Schrödinger equation and the fractional path integral are new fundamental physical concepts introduced and elaborated in the book. The fractional Schrödinger equation is a manifestation of fractional quantum mechanics. The fractional path integral is a new mathematical tool based on integration over Lévy flights. The fractional path integral method enhances the well-known Feynman path integral framework. Related topics covered in the text include time fractional quantum mechanics, fractional statistical mechanics, fractional classical mechanics and the α-stable Lévy random process. The book is well-suited for theorists, pure and applied mathematicians, solid-state physicists, chemists, and others working with the Schrödinger equation, the path integral technique...

Fundamental Degradation Mechanisms of Multi-Functional Nanoengineered Surfaces

Science.gov (United States)

2018-04-08

not simultaneously). The first student (Patricia Weisensee) has graduated and is currently an Assistant Professor in the Mechanical Engineering ...is planning on remaining for his PhD after obtaining his masters and Hyeongyun is planning on pursuing an academic career in the US after obtaining...progress, Hyeongyun Cha has recently received the Mavis Faculty Fellowship, developed in the College of Engineering to facilitate the training of the

Nuclear multifragmentation, its relation to general physics. A rich test ground of the fundamentals of statistical mechanics

International Nuclear Information System (INIS)

Gross, D.H.E.

2006-01-01

Heat can flow from cold to hot at any phase separation even in macroscopic systems. Therefore also Lynden-Bell's famous gravo-thermal catastrophe must be reconsidered. In contrast to traditional canonical Boltzmann-Gibbs statistics this is correctly described only by microcanonical statistics. Systems studied in chemical thermodynamics (ChTh) by using canonical statistics consist of several homogeneous macroscopic phases. Evidently, macroscopic statistics as in chemistry cannot and should not be applied to non-extensive or inhomogeneous systems like nuclei or galaxies. Nuclei are small and inhomogeneous. Multifragmented nuclei are even more inhomogeneous and the fragments even smaller. Phase transitions of first order and especially phase separations therefore cannot be described by a (homogeneous) canonical ensemble. Taking this serious, fascinating perspectives open for statistical nuclear fragmentation as test ground for the basic principles of statistical mechanics, especially of phase transitions, without the use of the thermodynamic limit. Moreover, there is also a lot of similarity between the accessible phase space of fragmenting nuclei and inhomogeneous multistellar systems. This underlines the fundamental significance for statistical physics in general. (orig.)

Exchange Rates and Fundamentals.

Science.gov (United States)

Engel, Charles; West, Kenneth D.

2005-01-01

We show analytically that in a rational expectations present-value model, an asset price manifests near-random walk behavior if fundamentals are I (1) and the factor for discounting future fundamentals is near one. We argue that this result helps explain the well-known puzzle that fundamental variables such as relative money supplies, outputs,…

Radiology fundamentals

CERN Document Server

Singh, Harjit

2011-01-01

""Radiology Fundamentals"" is a concise introduction to the dynamic field of radiology for medical students, non-radiology house staff, physician assistants, nurse practitioners, radiology assistants, and other allied health professionals. The goal of the book is to provide readers with general examples and brief discussions of basic radiographic principles and to serve as a curriculum guide, supplementing a radiology education and providing a solid foundation for further learning. Introductory chapters provide readers with the fundamental scientific concepts underlying the medical use of imag

Updates on tetanus toxin: a fundamental approach

Directory of Open Access Journals (Sweden)

Md. Ahaduzzaman

2015-03-01

Full Text Available Clostridium tetani is an anaerobic bacterium that produces second most poisonous protein toxins than any other bacteria. Tetanus in animals is sporadic in nature but difficult to combat even by using antibiotics and antiserum. It is crucial to understand the fundamental mechanisms and signals that control toxin production for advance research and medicinal uses. This review was intended for better understanding the basic patho-physiology of tetanus and neurotoxins (TeNT among the audience of related field.

Fundamentals of laser-assisted micro- and nanotechnologies

CERN Document Server

Konov, Vitaly

2014-01-01

This book covers the state of the art of laser micro- and nanotechnology. The physical fundamentals of different processes and the application are presented. The book deals with different materials like phase change and memory alloys, thin films, polymers etc. New phenomena and mechanisms of laser-matter interaction in nano-domains are explained. This book is helpful for students, postgraduates, engineers and researches working not only in the field of laser microtechnology but also in high-tech industry, like photonics, microelectronics, information technology.

Molecular mechanism of allosteric communication in Hsp70 revealed by molecular dynamics simulations.

Directory of Open Access Journals (Sweden)

Federica Chiappori

Full Text Available Investigating ligand-regulated allosteric coupling between protein domains is fundamental to understand cell-life regulation. The Hsp70 family of chaperones represents an example of proteins in which ATP binding and hydrolysis at the Nucleotide Binding Domain (NBD modulate substrate recognition at the Substrate Binding Domain (SBD. Herein, a comparative analysis of an allosteric (Hsp70-DnaK and a non-allosteric structural homolog (Hsp110-Sse1 of the Hsp70 family is carried out through molecular dynamics simulations, starting from different conformations and ligand-states. Analysis of ligand-dependent modulation of internal fluctuations and local deformation patterns highlights the structural and dynamical changes occurring at residue level upon ATP-ADP exchange, which are connected to the conformational transition between closed and open structures. By identifying the dynamically responsive protein regions and specific cross-domain hydrogen-bonding patterns that differentiate Hsp70 from Hsp110 as a function of the nucleotide, we propose a molecular mechanism for the allosteric signal propagation of the ATP-encoded conformational signal.

Mechanism of the Glycosidic Bond Cleavage of Mismatched Thymine in Human Thymine DNA Glycosylase Revealed by Classical Molecular Dynamics and Quantum Mechanical/Molecular Mechanical Calculations.

Science.gov (United States)

Kanaan, Natalia; Crehuet, Ramon; Imhof, Petra

2015-09-24

Base excision of mismatched or damaged nucleotides catalyzed by glycosylase enzymes is the first step of the base excision repair system, a machinery preserving the integrity of DNA. Thymine DNA glycosylase recognizes and removes mismatched thymine by cleaving the C1'-N1 bond between the base and the sugar ring. Our quantum mechanical/molecular mechanical calculations of this reaction in human thymine DNA glycosylase reveal a requirement for a positive charge in the active site to facilitate C1'-N1 bond scission: protonation of His151 significantly lowers the free energy barrier for C1'-N1 bond dissociation compared to the situation with neutral His151. Shuttling a proton from His151 to the thymine base further reduces the activation free energy for glycosidic bond cleavage. Classical molecular dynamics simulations of the H151A mutant suggest that the mutation to the smaller, neutral, residue increases the water accessibility of the thymine base, rendering direct proton transfer from the bulk feasible. Quantum mechanical/molecular mechanical calculations of the glycosidic bond cleavage reaction in the H151A mutant show that the activation free energy is slightly lower than in the wild-type enzyme, explaining the experimentally observed higher reaction rates in this mutant.

Arguing against fundamentality

Science.gov (United States)

McKenzie, Kerry

This paper aims to open up discussion on the relationship between fundamentality and naturalism, and in particular on the question of whether fundamentality may be denied on naturalistic grounds. A historico-inductive argument for an anti-fundamentalist conclusion, prominent within the contemporary metaphysical literature, is examined; finding it wanting, an alternative 'internal' strategy is proposed. By means of an example from the history of modern physics - namely S-matrix theory - it is demonstrated that (1) this strategy can generate similar (though not identical) anti-fundamentalist conclusions on more defensible naturalistic grounds, and (2) that fundamentality questions can be empirical questions. Some implications and limitations of the proposed approach are discussed.

Correlated motions are a fundamental property of β-sheets

Science.gov (United States)

Fenwick, R. Bryn; Orellana, Laura; Esteban-Martín, Santi; Orozco, Modesto; Salvatella, Xavier

2014-06-01

Correlated motions in proteins can mediate fundamental biochemical processes such as signal transduction and allostery. The mechanisms that underlie these processes remain largely unknown due mainly to limitations in their direct detection. Here, based on a detailed analysis of protein structures deposited in the protein data bank, as well as on state-of-the art molecular simulations, we provide general evidence for the transfer of structural information by correlated backbone motions, mediated by hydrogen bonds, across β-sheets. We also show that the observed local and long-range correlated motions are mediated by the collective motions of β-sheets and investigate their role in large-scale conformational changes. Correlated motions represent a fundamental property of β-sheets that contributes to protein function.

Revealing the Interface Structure and Bonding Mechanism of Coupling Agent Treated WPC

Directory of Open Access Journals (Sweden)

Jiuping Rao

2018-03-01

Full Text Available This paper presents the interfacial optimisation of wood plastic composites (WPC based on recycled wood flour and polyethylene by employing maleated and silane coupling agents. The effect of the incorporation of the coupling agents on the variation of chemical structure of the composites were investigated by Attenuated total reflectance-Fourier Transform Infrared spectroscopy (ATR-FTIR and Solid state 13C Nuclear Magnetic Resonance spectroscopy (NMR analyses. The results revealed the chemical reactions that occurred between the coupling agents and raw materials, which thus contributed to the enhancement of compatibility and interfacial adhesion between the constituents of WPC. NMR results also indicated that there existed the transformation of crystalline cellulose to an amorphous state during the coupling agent treatments, reflecting the inferior resonance of crystalline carbohydrates. Fluorescence Microscope (FM and Scanning Electron Microscope (SEM analyses showed the improvements of wood particle dispersion and wettability, compatibility of the constituents, and resin penetration, and impregnation of the composites after the coupling agent treatments. The optimised interface of the composites was attributed to interdiffusion, electrostatic adhesion, chemical reactions, and mechanical interlocking bonding mechanisms.

Quantum mechanical electronic structure calculation reveals orientation dependence of hydrogen bond energy in proteins.

Science.gov (United States)

Mondal, Abhisek; Datta, Saumen

2017-06-01

Hydrogen bond plays a unique role in governing macromolecular interactions with exquisite specificity. These interactions govern the fundamental biological processes like protein folding, enzymatic catalysis, molecular recognition. Despite extensive research work, till date there is no proper report available about the hydrogen bond's energy surface with respect to its geometric parameters, directly derived from proteins. Herein, we have deciphered the potential energy landscape of hydrogen bond directly from the macromolecular coordinates obtained from Protein Data Bank using quantum mechanical electronic structure calculations. The findings unravel the hydrogen bonding energies of proteins in parametric space. These data can be used to understand the energies of such directional interactions involved in biological molecules. Quantitative characterization has also been performed using Shannon entropic calculations for atoms participating in hydrogen bond. Collectively, our results constitute an improved way of understanding hydrogen bond energies in case of proteins and complement the knowledge-based potential. Proteins 2017; 85:1046-1055. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

ULTRASONIC STUDIES OF THE FUNDAMENTAL MECHANISMS OF RECRYSTALLIZATION AND SINTERING OF METALS

Energy Technology Data Exchange (ETDEWEB)

TURNER, JOSEPH A.

2005-11-30

The purpose of this project was to develop a fundamental understanding of the interaction of an ultrasonic wave with complex media, with specific emphases on recrystallization and sintering of metals. A combined analytical, numerical, and experimental research program was implemented. Theoretical models of elastic wave propagation through these complex materials were developed using stochastic wave field techniques. The numerical simulations focused on finite element wave propagation solutions through complex media. The experimental efforts were focused on corroboration of the models developed and on the development of new experimental techniques. The analytical and numerical research allows the experimental results to be interpreted quantitatively.

Bohmian mechanics with complex action: A new trajectory-based formulation of quantum mechanics

International Nuclear Information System (INIS)

Goldfarb, Yair; Degani, Ilan; Tannor, David J.

2006-01-01

In recent years there has been a resurgence of interest in Bohmian mechanics as a numerical tool because of its local dynamics, which suggest the possibility of significant computational advantages for the simulation of large quantum systems. However, closer inspection of the Bohmian formulation reveals that the nonlocality of quantum mechanics has not disappeared--it has simply been swept under the rug into the quantum force. In this paper we present a new formulation of Bohmian mechanics in which the quantum action, S, is taken to be complex. This leads to a single equation for complex S, and ultimately complex x and p but there is a reward for this complexification - a significantly higher degree of localization. The quantum force in the new approach vanishes for Gaussian wave packet dynamics, and its effect on barrier tunneling processes is orders of magnitude lower than that of the classical force. In fact, the current method is shown to be a rigorous extension of generalized Gaussian wave packet dynamics to give exact quantum mechanics. We demonstrate tunneling probabilities that are in virtually perfect agreement with the exact quantum mechanics down to 10 -7 calculated from strictly localized quantum trajectories that do not communicate with their neighbors. The new formulation may have significant implications for fundamental quantum mechanics, ranging from the interpretation of non-locality to measures of quantum complexity

Revealing the Differences Between Free and Complexed Enzyme Mechanisms and Factors Contributing to Cell Wall Recalcitrance

Energy Technology Data Exchange (ETDEWEB)

Resch, Michael G.; Donohoe, Byron; Ciesielski, Peter; Nill, Jennifer; McKinney, Kellene; Mittal, Ashutosh; Katahira, Rui; Himmel, Michael; Biddy, Mary; Beckham, Gregg; Decker, Steve

2014-09-08

Enzymatic depolymerization of polysaccharides is a key step in the production of fuels and chemicals from lignocellulosic biomass, and discovery of synergistic biomass-degrading enzyme paradigms will enable improved conversion processes. Historically, revealing insights into enzymatic saccharification mechanisms on plant cell walls has been hindered by uncharacterized substrates and low resolution.

Fundamental processes in ion plating

International Nuclear Information System (INIS)

Mattox, D.M.

1980-01-01

Ion plating is a generic term applied to film deposition processes in which the substrate surface and/or the depositing film is subjected to a flux of high energy particles sufficient to cause changes in the interfacial region of film properties compared to a nonbombarded deposition. Ion plating is being accepted as an alternative coating technique to sputter deposition, vacuum evaporation and electroplating. In order to intelligently choose between the various deposition techniques, the fundamental mechanisms, relating to ion plating, must be understood. This paper reviews the effects of low energy ion bombardment on surfaces, interface formation and film development as they apply to ion plating and the implementation and applications of the ion plating process

Defect-related internal dissipation in mechanical resonators and the study of coupled mechanical systems.

Energy Technology Data Exchange (ETDEWEB)

Friedmann, Thomas Aquinas; Czaplewski, David A.; Sullivan, John Patrick; Modine, Normand Arthur; Wendt, Joel Robert; Aslam, Dean (Michigan State University, Lansing, MI); Sepulveda-Alancastro, Nelson (University of Puerto Rico, Mayaguez, PR)

2007-01-01

Understanding internal dissipation in resonant mechanical systems at the micro- and nanoscale is of great technological and fundamental interest. Resonant mechanical systems are central to many sensor technologies, and microscale resonators form the basis of a variety of scanning probe microscopies. Furthermore, coupled resonant mechanical systems are of great utility for the study of complex dynamics in systems ranging from biology to electronics to photonics. In this work, we report the detailed experimental study of internal dissipation in micro- and nanomechanical oscillators fabricated from amorphous and crystalline diamond materials, atomistic modeling of dissipation in amorphous, defect-free, and defect-containing crystalline silicon, and experimental work on the properties of one-dimensional and two-dimensional coupled mechanical oscillator arrays. We have identified that internal dissipation in most micro- and nanoscale oscillators is limited by defect relaxation processes, with large differences in the nature of the defects as the local order of the material ranges from amorphous to crystalline. Atomistic simulations also showed a dominant role of defect relaxation processes in controlling internal dissipation. Our studies of one-dimensional and two-dimensional coupled oscillator arrays revealed that it is possible to create mechanical systems that should be ideal for the study of non-linear dynamics and localization.

Fundamental neutron physics

International Nuclear Information System (INIS)

Deslattes, R.; Dombeck, T.; Greene, G.; Ramsey, N.; Rauch, H.; Werner, S.

1984-01-01

Fundamental physics experiments of merit can be conducted at the proposed intense neutron sources. Areas of interest include: neutron particle properties, neutron wave properties, and fundamental physics utilizing reactor produced γ-rays. Such experiments require intense, full-time utilization of a beam station for periods ranging from several months to a year or more

A study on the fundamental mechanism and the evolutionary driving forces behind aerobic fermentation in yeast.

Science.gov (United States)

Hagman, Arne; Piškur, Jure

2015-01-01

Baker's yeast Saccharomyces cerevisiae rapidly converts sugars to ethanol and carbon dioxide at both anaerobic and aerobic conditions. The later phenomenon is called Crabtree effect and has been described in two forms, long-term and short-term effect. We have previously studied under fully controlled aerobic conditions forty yeast species for their central carbon metabolism and the presence of long-term Crabtree effect. We have also studied ten steady-state yeast cultures, pulsed them with glucose, and followed the central carbon metabolism and the appearance of ethanol at dynamic conditions. In this paper we analyzed those wet laboratory data to elucidate possible mechanisms that determine the fate of glucose in different yeast species that cover approximately 250 million years of evolutionary history. We determine overflow metabolism to be the fundamental mechanism behind both long- and short-term Crabtree effect, which originated approximately 125-150 million years ago in the Saccharomyces lineage. The "invention" of overflow metabolism was the first step in the evolution of aerobic fermentation in yeast. It provides a general strategy to increase energy production rates, which we show is positively correlated to growth. The "invention" of overflow has also simultaneously enabled rapid glucose consumption in yeast, which is a trait that could have been selected for, to "starve" competitors in nature. We also show that glucose repression of respiration is confined mainly among S. cerevisiae and closely related species that diverged after the whole genome duplication event, less than 100 million years ago. Thus, glucose repression of respiration was apparently "invented" as a second step to further increase overflow and ethanol production, to inhibit growth of other microbes. The driving force behind the initial evolutionary steps was most likely competition with other microbes to faster consume and convert sugar into biomass, in niches that were semi-anaerobic.

A study on the fundamental mechanism and the evolutionary driving forces behind aerobic fermentation in yeast.

Directory of Open Access Journals (Sweden)

Arne Hagman

Full Text Available Baker's yeast Saccharomyces cerevisiae rapidly converts sugars to ethanol and carbon dioxide at both anaerobic and aerobic conditions. The later phenomenon is called Crabtree effect and has been described in two forms, long-term and short-term effect. We have previously studied under fully controlled aerobic conditions forty yeast species for their central carbon metabolism and the presence of long-term Crabtree effect. We have also studied ten steady-state yeast cultures, pulsed them with glucose, and followed the central carbon metabolism and the appearance of ethanol at dynamic conditions. In this paper we analyzed those wet laboratory data to elucidate possible mechanisms that determine the fate of glucose in different yeast species that cover approximately 250 million years of evolutionary history. We determine overflow metabolism to be the fundamental mechanism behind both long- and short-term Crabtree effect, which originated approximately 125-150 million years ago in the Saccharomyces lineage. The "invention" of overflow metabolism was the first step in the evolution of aerobic fermentation in yeast. It provides a general strategy to increase energy production rates, which we show is positively correlated to growth. The "invention" of overflow has also simultaneously enabled rapid glucose consumption in yeast, which is a trait that could have been selected for, to "starve" competitors in nature. We also show that glucose repression of respiration is confined mainly among S. cerevisiae and closely related species that diverged after the whole genome duplication event, less than 100 million years ago. Thus, glucose repression of respiration was apparently "invented" as a second step to further increase overflow and ethanol production, to inhibit growth of other microbes. The driving force behind the initial evolutionary steps was most likely competition with other microbes to faster consume and convert sugar into biomass, in niches that

Structure of protease-cleaved Escherichia coli α-2-macroglobulin reveals a putative mechanism of conformational activation for protease entrapment

International Nuclear Information System (INIS)

Fyfe, Cameron D.; Grinter, Rhys; Josts, Inokentijs; Mosbahi, Khedidja; Roszak, Aleksander W.; Cogdell, Richard J.; Wall, Daniel M.; Burchmore, Richard J. S.; Byron, Olwyn; Walker, Daniel

2015-01-01

The X-ray structure of protease-cleaved E. coli α-2-macroglobulin is described, which reveals a putative mechanism of activation and conformational change essential for protease inhibition. Bacterial α-2-macroglobulins have been suggested to function in defence as broad-spectrum inhibitors of host proteases that breach the outer membrane. Here, the X-ray structure of protease-cleaved Escherichia coli α-2-macroglobulin is described, which reveals a putative mechanism of activation and conformational change essential for protease inhibition. In this competitive mechanism, protease cleavage of the bait-region domain results in the untethering of an intrinsically disordered region of this domain which disrupts native interdomain interactions that maintain E. coli α-2-macroglobulin in the inactivated form. The resulting global conformational change results in entrapment of the protease and activation of the thioester bond that covalently links to the attacking protease. Owing to the similarity in structure and domain architecture of Escherichia coli α-2-macroglobulin and human α-2-macroglobulin, this protease-activation mechanism is likely to operate across the diverse members of this group

Structure of protease-cleaved Escherichia coli α-2-macroglobulin reveals a putative mechanism of conformational activation for protease entrapment

Energy Technology Data Exchange (ETDEWEB)

Fyfe, Cameron D.; Grinter, Rhys; Josts, Inokentijs; Mosbahi, Khedidja [University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); Roszak, Aleksander W. [University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); Cogdell, Richard J.; Wall, Daniel M.; Burchmore, Richard J. S.; Byron, Olwyn; Walker, Daniel, E-mail: daniel.walker@glasgow.ac.uk [University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom)

2015-06-30

The X-ray structure of protease-cleaved E. coli α-2-macroglobulin is described, which reveals a putative mechanism of activation and conformational change essential for protease inhibition. Bacterial α-2-macroglobulins have been suggested to function in defence as broad-spectrum inhibitors of host proteases that breach the outer membrane. Here, the X-ray structure of protease-cleaved Escherichia coli α-2-macroglobulin is described, which reveals a putative mechanism of activation and conformational change essential for protease inhibition. In this competitive mechanism, protease cleavage of the bait-region domain results in the untethering of an intrinsically disordered region of this domain which disrupts native interdomain interactions that maintain E. coli α-2-macroglobulin in the inactivated form. The resulting global conformational change results in entrapment of the protease and activation of the thioester bond that covalently links to the attacking protease. Owing to the similarity in structure and domain architecture of Escherichia coli α-2-macroglobulin and human α-2-macroglobulin, this protease-activation mechanism is likely to operate across the diverse members of this group.

Computational biomechanics for medicine fundamental science and patient-specific applications

CERN Document Server

Miller, Karol; Wittek, Adam; Nielsen, Poul

2014-01-01

One of the greatest challenges facing the computational engineering community is to extend the success of computational mechanics to fields outside traditional engineering, in particular to biology, the biomedical sciences, and medicine. The Computational Biomechanics for Medicine titles provide an opportunity for specialists in computational biomechanics to present their latest methodologies and advancements. This latest installment comprises nine of the latest developments in both fundamental science and patient-specific applications, from researchers in Australia, New Zealand, USA, UK, France, Ireland, and China. Some of the interesting topics discussed are: cellular mechanics; tumor growth and modeling; medical image analysis; and both patient-specific fluid dynamics and solid mechanics simulations.

Islamic fundamentalism in Indonesia

OpenAIRE

Nagy, Sandra L.

1996-01-01

This is a study of Islamic fundamentalism in Indonesia. Islamic fundamentalism is defined as the return to the foundations and principles of Islam including all movements based on the desire to create a more Islamic society. After describing the practices and beliefs of Islam, this thesis examines the three aspects of universal Islamic fundamentalism: revivalism, resurgence, and radicalism. It analyzes the role of Islam in Indonesia under Dutch colonial rule, an alien Christian imperialist po...

Atom Interferometry for Fundamental Physics and Gravity Measurements in Space

Science.gov (United States)

Kohel, James M.

2012-01-01

Laser-cooled atoms are used as freefall test masses. The gravitational acceleration on atoms is measured by atom-wave interferometry. The fundamental concept behind atom interferometry is the quantum mechanical particle-wave duality. One can exploit the wave-like nature of atoms to construct an atom interferometer based on matter waves analogous to laser interferometers.

Bell trajectories for revealing quantum control mechanisms

International Nuclear Information System (INIS)

Dennis, Eric; Rabitz, Herschel

2003-01-01

The dynamics induced while controlling quantum systems by optimally shaped laser pulses have often been difficult to understand in detail. A method is presented for quantifying the importance of specific sequences of quantum transitions involved in the control process. The method is based on a ''beable'' formulation of quantum mechanics due to John Bell that rigorously maps the quantum evolution onto an ensemble of stochastic trajectories over a classical state space. Detailed mechanism identification is illustrated with a model seven-level system. A general procedure is presented to extract mechanism information directly from closed-loop control experiments. Application to simulated experimental data for the model system proves robust with up to 25% noise

Fundamentals of lead-free solder interconnect technology from microstructures to reliability

CERN Document Server

Lee, Tae-Kyu; Kim, Choong-Un; Ma, Hongtao

2015-01-01

This unique book provides an up-to-date overview of the fundamental concepts behind lead-free solder and interconnection technology. Readers will find a description of the rapidly increasing presence of electronic systems in all aspects of modern life as well as the increasing need for predictable reliability in electronic systems. The physical and mechanical properties of lead-free solders are examined in detail, and building on fundamental science, the mechanisms responsible for damage and failure evolution, which affect reliability of lead-free solder joints are identified based on microstructure evolution.  The continuing miniaturization of electronic systems will increase the demand on the performance of solder joints, which will require new alloy and processing strategies as well as interconnection design strategies. This book provides a foundation on which improved performance and new design approaches can be based.  In summary, this book:  Provides an up-to-date overview on lead-free soldering tech...

Data integration reveals key homeostatic mechanisms following low dose radiation exposure

Energy Technology Data Exchange (ETDEWEB)

Tilton, Susan C.; Matzke, Melissa M. [Computational Biology and Bioinformatics, Pacific Northwest National Laboratory, Richland, WA 99338 (United States); Sowa, Marianne B.; Stenoien, David L.; Weber, Thomas J. [Health Impacts and Exposure Science, Pacific Northwest National Laboratory, Richland, WA 99338 (United States); Morgan, William F. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99338 (United States); Waters, Katrina M., E-mail: katrina.waters@pnnl.gov [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99338 (United States)

2015-05-15

The goal of this study was to define pathways regulated by low dose radiation to understand how biological systems respond to subtle perturbations in their environment and prioritize pathways for human health assessment. Using an in vitro 3-D human full thickness skin model, we have examined the temporal response of dermal and epidermal layers to 10 cGy X-ray using transcriptomic, proteomic, phosphoproteomic and metabolomic platforms. Bioinformatics analysis of each dataset independently revealed potential signaling mechanisms affected by low dose radiation, and integrating data shed additional insight into the mechanisms regulating low dose responses in human tissue. We examined direct interactions among datasets (top down approach) and defined several hubs as significant regulators, including transcription factors (YY1, MYC and CREB1), kinases (CDK2, PLK1) and a protease (MMP2). These data indicate a shift in response across time — with an increase in DNA repair, tissue remodeling and repression of cell proliferation acutely (24–72 h). Pathway-based integration (bottom up approach) identified common molecular and pathway responses to low dose radiation, including oxidative stress, nitric oxide signaling and transcriptional regulation through the SP1 factor that would not have been identified by the individual data sets. Significant regulation of key downstream metabolites of nitrative stress was measured within these pathways. Among the features identified in our study, the regulation of MMP2 and SP1 was experimentally validated. Our results demonstrate the advantage of data integration to broadly define the pathways and networks that represent the mechanisms by which complex biological systems respond to perturbation. - Highlights: • Low dose ionizing radiation altered homeostasis in 3D skin tissue model. • Global gene/protein/metabolite data integrated using complementary statistical approaches • Time and location-specific change in matrix regulation

The Physical Mechanism of Frictional Aging Revealed by Nanoindentation Creep

Science.gov (United States)

Thom, C.; Carpick, R. W.; Goldsby, D. L.

2017-12-01

A classical observation from rock friction experiments is that friction increases linearly with the logarithm of the time of stationary contact, a phenomenon sometimes referred to as aging. Aging is most often attributed to an increase in the real area of contact due to asperity creep. However, recent atomic force microscopy (AFM) experiments and molecular dynamics simulations suggest that time-dependent siloxane (Si—O—Si) bonding gives rise to aging in silica-silica contacts in the absence of plastic deformation. Determining whether an increase in contact `quantity' (due to creep), contact `quality' (due to chemical bonding), or another unknown mechanism causes aging is a challenging experimental task, despite its importance for developing a physical basis for rate and state friction laws. An intriguing observation is that aging is absent in friction experiments on quartz rocks and gouge at humidities water on asperity creep (via hydrolytic weakening) or on the adhesive strength of contacts. To discern between these possibilities, we have conducted nanoindentation experiments on single crystals of quartz to measure their indentation hardness and creep behavior at humidities of 2% to 50%, and in vacuum. Samples were loaded at 1000 mN/s to a peak load of 15, 40, or 400 mN, which was then held constant for 10 s. After the peak load is reached, the tip sinks into the material with time due to creep of the indentation contact. Our experiments reveal that there is no effect of varying humidity on either indentation hardness or indentation creep behavior over the full range of humidities investigated. If asperity creep were the dominant mechanism of frictional aging for quartz in the experiments cited above, then significant increases in hardness and decreases in the growth rate of indentation contacts at low humidities is expected, in stark contrast with our nanoindentation data. Our experiments indicate that asperity creep cannot be the cause of aging in quartz

Fundamentals of colour awareness: a literature review

OpenAIRE

A. Rubin

2005-01-01

A description of some of the basic or funda-mental aspects of the colour sensory mechanism will be provided here, based on modern ideas and literature, with reference specifically to the likely origins and evolution of colour vision.  The mo-lecular basis for colour awareness and the human colour pathway will also be considered in some detail. This paper intends to provide the theoreti-cal and philosophical basis for further papers that will introduce a modern and original computer- based  met...

Reciprocal osmotic challenges reveal mechanisms of divergence in phenotypic plasticity in the killifish Fundulus heteroclitus.

Science.gov (United States)

Brennan, Reid S; Galvez, Fernando; Whitehead, Andrew

2015-04-15

The killifish Fundulus heteroclitus is an estuarine species with broad physiological plasticity, enabling acclimation to diverse stressors. Previous work suggests that freshwater populations expanded their physiology to accommodate low salinity environments; however, it is unknown whether this compromises their tolerance to high salinity. We used a comparative approach to investigate the mechanisms of a derived freshwater phenotype and the fate of an ancestral euryhaline phenotype after invasion of a freshwater environment. We compared physiological and transcriptomic responses to high- and low-salinity stress in fresh and brackish water populations and found an enhanced plasticity to low salinity in the freshwater population coupled with a reduced ability to acclimate to high salinity. Transcriptomic data identified genes with a conserved common response, a conserved salinity-dependent response and responses associated with population divergence. Conserved common acclimation responses revealed stress responses and alterations in cell-cycle regulation as important mechanisms in the general osmotic response. Salinity-specific responses included the regulation of genes involved in ion transport, intracellular calcium, energetic processes and cellular remodeling. Genes diverged between populations were primarily those showing salinity-specific expression and included those regulating polyamine homeostasis and the cell cycle. Additionally, when populations were matched with their native salinity, expression patterns were consistent with the concept of 'transcriptomic resilience', suggesting local adaptation. These findings provide insight into the fate of a plastic phenotype after a shift in environmental salinity and help to reveal mechanisms allowing for euryhalinity. © 2015. Published by The Company of Biologists Ltd.

Fundamentals of ergonomic exoskeleton robots

NARCIS (Netherlands)

Schiele, A.

2008-01-01

This thesis is the first to provide the fundamentals of ergonomic exoskeleton design. The fundamental theory as well as technology necessary to analyze and develop ergonomic wearable robots interacting with humans is established and validated by experiments and prototypes. The fundamentals are (1) a

Open and closed string worldsheets from free large N gauge theories with adjoint and fundamental matter

International Nuclear Information System (INIS)

Yaakov, Itamar

2006-01-01

We extend Gopakumar's prescription for constructing closed string worldsheets from free field theory diagrams with adjoint matter to open and closed string worldsheets arising from free field theories with fundamental matter. We describe the extension of the gluing mechanism and the electrical circuit analogy to fundamental matter. We discuss the generalization of the existence and uniqueness theorem of Strebel differentials to open Riemann surfaces. Two examples are computed of correlators containing fundamental matter, and the resulting worldsheet OPE's are computed. Generic properties of Gopakumar's construction are discussed

Attention: Reaction Time and Accuracy Reveal Different Mechanisms

Science.gov (United States)

Prinzmetal, William; McCool, Christin; Park, Samuel

2005-01-01

The authors propose that there are 2 different mechanisms whereby spatial cues capture attention. The voluntary mechanism is the strategic allocation of perceptual resources to the location most likely to contain the target. The involuntary mechanism is a reflexive orienting response that occurs even when the spatial cue does not indicate the…

Cartilaginous Metabolomic Study Reveals Potential Mechanisms of Osteophyte Formation in Osteoarthritis.

Science.gov (United States)

Xu, Zhongwei; Chen, Tingmei; Luo, Jiao; Ding, Shijia; Gao, Sichuan; Zhang, Jian

2017-04-07

Osteophyte is one of the inevitable consequences of progressive osteoarthritis with the main characteristics of cartilage degeneration and endochondral ossification. The pathogenesis of osteophyte formation is not fully understood to date. In this work, metabolomic approaches were employed to explore potential mechanisms of osteophyte formation by detecting metabolic variations between extracts of osteophyte cartilage tissues (n = 32) and uninvolved control cartilage tissues (n = 34), based on the platform of ultraperformance liquid chromatography tandem quadrupole time-of-flight mass spectrometry, as well as the use of multivariate statistic analysis and univariate statistic analysis. The osteophyte group was significantly separated from the control group by the orthogonal partial least-squares discriminant analysis models, indicating that metabolic state of osteophyte cartilage had been changed. In total, 28 metabolic variations further validated by mass spectrum (MS) match, tandom mass spectrum (MS/MS) match, and standards match mainly included amino acids, sulfonic acids, glycerophospholipids, and fatty acyls. These metabolites were related to some specific physiological or pathological processes (collagen dissolution, boundary layers destroyed, self-restoration triggered, etc.) which might be associated with the procedure of osteophyte formation. Pathway analysis showed phenylalanine metabolism (PI = 0.168, p = 0.004) was highly correlative to this degenerative process. Our findings provided a direction for targeted metabolomic study and an insight into further reveal the molecular mechanisms of ostophyte formation.

The Fundamental Structure and the Reproduction of Spiral Wave in a Two-Dimensional Excitable Lattice.

Science.gov (United States)

Qian, Yu; Zhang, Zhaoyang

2016-01-01

In this paper we have systematically investigated the fundamental structure and the reproduction of spiral wave in a two-dimensional excitable lattice. A periodically rotating spiral wave is introduced as the model to reproduce spiral wave artificially. Interestingly, by using the dominant phase-advanced driving analysis method, the fundamental structure containing the loop structure and the wave propagation paths has been revealed, which can expose the periodically rotating orbit of spiral tip and the charity of spiral wave clearly. Furthermore, the fundamental structure is utilized as the core for artificial spiral wave. Additionally, the appropriate parameter region, in which the artificial spiral wave can be reproduced, is studied. Finally, we discuss the robustness of artificial spiral wave to defects.

Fundamental concepts in Particle Physics course

CERN Multimedia

CERN. Geneva HR-RFA

2006-01-01

The course will provide an introduction to some of the basic theoretical techniques used to describe the fundamental particles and their interactions. Of central importance to our understanding of these forces are the underlying symmetries of nature and I will review the nature of these symmetries and how they are used to build a predictive theory. I discuss how the combination of quantum mechanics and relativity leads to the quantum field theory (QFT) description of the states of matter and their interactions. The Feynman rules used to determine the QFT predictions for experimentally measurable processes are derived and applied to the calculation of decay widths and cross sections.

A Fundamental Scale of Descriptions for Analyzing Information Content of Communication Systems

Directory of Open Access Journals (Sweden)

Gerardo Febres

2015-03-01

Full Text Available The complexity of the description of a system is a function of the entropy of its symbolic description. Prior to computing the entropy of the system’s description, an observation scale has to be assumed. In texts written in artificial and natural languages, typical scales are binary, characters, and words. However, considering languages as structures built around certain preconceived set of symbols, like words or characters, limits the level of complexity that can be revealed analytically. This study introduces the notion of the fundamental description scale to analyze the essence of the structure of a language. The concept of Fundamental Scale is tested for English and musical instrument digital interface (MIDI music texts using an algorithm developed to split a text in a collection of sets of symbols that minimizes the observed entropy of the system. This Fundamental Scale reflects more details of the complexity of the language than using bits, characters or words. Results show that this Fundamental Scale allows to compare completely different languages, such as English and MIDI coded music regarding its structural entropy. This comparative power facilitates the study of the complexity of the structure of different communication systems.

Presynaptic mechanisms of lead neurotoxicity: effects on vesicular release, vesicle clustering and mitochondria number.

Science.gov (United States)

Zhang, Xiao-Lei; Guariglia, Sara R; McGlothan, Jennifer L; Stansfield, Kirstie H; Stanton, Patric K; Guilarte, Tomás R

2015-01-01

Childhood lead (Pb2+) intoxication is a global public health problem and accounts for 0.6% of the global burden of disease associated with intellectual disabilities. Despite the recognition that childhood Pb2+ intoxication contributes significantly to intellectual disabilities, there is a fundamental lack of knowledge on presynaptic mechanisms by which Pb2+ disrupts synaptic function. In this study, using a well-characterized rodent model of developmental Pb2+ neurotoxicity, we show that Pb2+ exposure markedly inhibits presynaptic vesicular release in hippocampal Schaffer collateral-CA1 synapses in young adult rats. This effect was associated with ultrastructural changes which revealed a reduction in vesicle number in the readily releasable/docked vesicle pool, disperse vesicle clusters in the resting pool, and a reduced number of presynaptic terminals with multiple mitochondria with no change in presynaptic calcium influx. These studies provide fundamental knowledge on mechanisms by which Pb2+ produces profound inhibition of presynaptic vesicular release that contribute to deficits in synaptic plasticity and intellectual development.

Rheology of transgenic switchgrass reveals practical aspects of biomass processing.

Science.gov (United States)

Wan, Guigui; Frazier, Taylor; Jorgensen, Julianne; Zhao, Bingyu; Frazier, Charles E

2018-01-01

Mechanical properties of transgenic switchgrass have practical implications for biorefinery technologies. Presented are fundamentals for simple (thermo)mechanical measurements of genetically transformed switchgrass. Experimental basics are provided for the novice, where the intention is to promote collaboration between plant biologists and materials scientists. Stem sections were subjected to two stress modes: (1) torsional oscillation in the linear response region, and (2) unidirectional torsion to failure. Specimens were analyzed while submerged/saturated in ethylene glycol, simulating natural hydration and allowing experimental temperatures above 100 °C for an improved view of the lignin glass transition. Down-regulation of the 4-Coumarate:coenzyme A ligase gene (reduced lignin content and altered monomer composition) generally resulted in less stiff and weaker stems. These observations were associated with a reduction in the temperature and activation energy of the lignin glass transition, but surprisingly with no difference in the breadth and intensity of the tan  δ signal. The results showed promise in further investigations of how rheological methods relate to stem lignin content, composition, and functional properties in the field and in bioprocessing. Measurements such as these are complicated by small specimen size; however, torsional rheometers (relatively common in polymer laboratories) are well suited for this task. As opposed to the expense and complication of relative humidity control, solvent-submersion rheological methods effectively reveal fundamental structure/property relationships in plant tissues. Demonstrated are low-strain linear methods, and also nonlinear yield and failure analysis; the latter is very uncommon for typical rheological equipment.

Fundamental study on recovery uranium oxide from HEPA filters

International Nuclear Information System (INIS)

Izumida, T.; Noguchi, Y.

1993-01-01

Large numbers of spent HEPA filters are produced at uranium fuel fabrication facilities. Uranium oxide particles have been collected on these filters. Then, a spent HEPA filter treatment system was developed from the viewpoint of recovering the UO 2 and minimizing the volume. The system consists of a mechanical separation process and a chemical dissolution process. This paper describes the results of fundamental experiments on recovering UO 2 from HEPA filters

International gas pricing in Europe and Asia: A crisis of fundamentals

International Nuclear Information System (INIS)

Stern, Jonathan

2014-01-01

In Continental Europe and LNG importing Asia, international gas prices reflect the market fundamentals of the 1970s–1990s when gas was replacing oil products and crude oil in energy balances. By the end of the 2000s, fundamentals in both these regions had changed significantly, but gas price formation mechanisms had not. This created major problems for buyers locked into long term contracts indexed to crude oil and oil product prices, which had risen to levels far above gas market fundamentals. By 2013, the transition to hub-based pricing was well advanced in Europe and dominant in the large markets in the north west of the Continent. In Asia the “crisis of fundamentals” was only just starting to be addressed with a transition to market pricing an urgent imperative, but still a distant prospect. - Highlights: • International gas prices in Europe and LNG importing Asia no longer reflect market fundamentals. • This became highly problematic in Europe post-2008 and in Japan post-Fukushima. • The result has been a significant switch to hub pricing in Europe. • In Asia, no substantial action has been taken beyond some new contracts based on Henry Hub prices

Damage analysis and fundamental studies for fusion reactor materials development

International Nuclear Information System (INIS)

Odette, G.R.; Lucas, G.E.

1991-09-01

The philosophy of the program at the University of California Santa Barbara has been to develop a fundamental understanding of both the basic damage processes and microstructural evolution that take place in a material during neutron irradiation and the consequent dimensional and mechanical property changes. This fundamental understanding can be used in conjunction with empirical data obtained from a variety of irradiation facilities to develop physically-based models of neutron irradiation effects in structural materials. The models in turn can be used to guide alloy development and to help extrapolate the irradiation data base (expected to be largely fission reactor based) to the fusion reactor regime. This philosophy is consistent with that of the national and international programs for developing structural materials for fusion reactors

Structural mechanism of laforin function in glycogen dephosphorylation and lafora disease.

Science.gov (United States)

Raththagala, Madushi; Brewer, M Kathryn; Parker, Matthew W; Sherwood, Amanda R; Wong, Brian K; Hsu, Simon; Bridges, Travis M; Paasch, Bradley C; Hellman, Lance M; Husodo, Satrio; Meekins, David A; Taylor, Adam O; Turner, Benjamin D; Auger, Kyle D; Dukhande, Vikas V; Chakravarthy, Srinivas; Sanz, Pascual; Woods, Virgil L; Li, Sheng; Vander Kooi, Craig W; Gentry, Matthew S

2015-01-22

Glycogen is the major mammalian glucose storage cache and is critical for energy homeostasis. Glycogen synthesis in neurons must be tightly controlled due to neuronal sensitivity to perturbations in glycogen metabolism. Lafora disease (LD) is a fatal, congenital, neurodegenerative epilepsy. Mutations in the gene encoding the glycogen phosphatase laforin result in hyperphosphorylated glycogen that forms water-insoluble inclusions called Lafora bodies (LBs). LBs induce neuronal apoptosis and are the causative agent of LD. The mechanism of glycogen dephosphorylation by laforin and dysfunction in LD is unknown. We report the crystal structure of laforin bound to phosphoglucan product, revealing its unique integrated tertiary and quaternary structure. Structure-guided mutagenesis combined with biophysical and biochemical analyses reveal the basis for normal function of laforin in glycogen metabolism. Analyses of LD patient mutations define the mechanism by which subsets of mutations disrupt laforin function. These data provide fundamental insights connecting glycogen metabolism to neurodegenerative disease. Copyright © 2015 Elsevier Inc. All rights reserved.

Fundamentals of friction and wear on the nanoscale

CERN Document Server

Gnecco, Enrico

2014-01-01

This book provides an updated review on the development of scanning probe microscopy and related techniques, and the availability of computational techniques not even imaginable a few decades ago. The 36 chapters cover instrumental aspects, theoretical models and selected experimental results, thus offering a broad panoramic view on fundamental issues in nanotribology which are currently being investigated. Compared to the first edition, several topics have been added, including triboluminescence, graphene mechanics, friction and wear in liquid environments, capillary condensation, and multisc

Discrete mechanics

CERN Document Server

Caltagirone, Jean-Paul

2014-01-01

This book presents the fundamental principles of mechanics to re-establish the equations of Discrete Mechanics. It introduces physics and thermodynamics associated to the physical modeling.  The development and the complementarity of sciences lead to review today the old concepts that were the basis for the development of continuum mechanics. The differential geometry is used to review the conservation laws of mechanics. For instance, this formalism requires a different location of vector and scalar quantities in space. The equations of Discrete Mechanics form a system of equations where the H

NATO Advanced Research Workshop on Fundamental and Applied Electromagnetics

CERN Document Server

Maksimenko, Sergey

2016-01-01

This book presents the most relevant and recent results in the study of “Nanoelectromagnetics”, a recently born fascinating research discipline, whose popularity is fast arising with the intensive penetration of nanotechnology in the world of electronics applications. Studying nanoelectromagnetics means describing the interaction between electromagnetic radiation and quantum mechanical low-dimensional systems: this requires a full interdisciplinary approach, the reason why this book hosts contributions from the fields of fundamental and applied electromagnetics, of chemistry and technology of nanostructures and nanocomposites, of physics of nano-structures systems, etc. The book is aimed at providing the reader with the state of the art in Nanoelectromagnetics, from theoretical modelling to experimental characterization, from design to synthesis, from DC to microwave and terahertz applications, from the study of fundamental material properties to the analysis of complex systems and devices, from commercia...

Quantum mechanics for pedestrians

CERN Document Server

Pade, Jochen

2014-01-01

This book provides an introduction into the fundamentals of non-relativistic quantum mechanics. In Part 1, the essential principles are developed. Applications and extensions of the formalism can be found in Part 2. The book includes not only material that is presented in traditional textbooks on quantum mechanics, but also discusses in detail current issues such as interaction-free quantum measurements, neutrino oscillations, various topics in the field of quantum information as well as fundamental problems and epistemological questions, such as the measurement problem, entanglement, Bell's inequality, decoherence, and the realism debate. A chapter on current interpretations of quantum mechanics concludes the book. To develop quickly and clearly the main principles of quantum mechanics and its mathematical formulation, there is a systematic change between wave mechanics and algebraic representation in the first chapters. The required mathematical tools are introduced step by step. Moreover, the appendix coll...

Double-lock ratchet mechanism revealing the role of  SER-344 in FoF1 ATP synthase

KAUST Repository

Beke-Somfai, T.

2011-03-07

In a majority of living organisms, FoF1 ATP synthase performs the fundamental process of ATP synthesis. Despite the simple net reaction formula, ADP+Pi→ATP+H2O, the detailed step-by-step mechanism of the reaction yet remains to be resolved owing to the complexity of this multisubunit enzyme. Based on quantum mechanical computations using recent high resolution X-ray structures, we propose that during ATP synthesis the enzyme first prepares the inorganic phosphate for the γP-OADP bond-forming step via a double-proton transfer. At this step, the highly conserved αS344 side chain plays a catalytic role. The reaction thereafter progresses through another transition state (TS) having a planar ion configuration to finally form ATP. These two TSs are concluded crucial for ATP synthesis. Using stepwise scans and several models of the nucleotide-bound active site, some of the most important conformational changes were traced toward direction of synthesis. Interestingly, as the active site geometry progresses toward the ATP-favoring tight binding site, at both of these TSs, a dramatic increase in barrier heights is observed for the reverse direction, i.e., hydrolysis of ATP. This change could indicate a "ratchet" mechanism for the enzyme to ensure efficacy of ATP synthesis by shifting residue conformation and thus locking access to the crucial TSs.

Revealing −1 Programmed Ribosomal Frameshifting Mechanisms by Single-Molecule Techniques and Computational Methods

Directory of Open Access Journals (Sweden)

Kai-Chun Chang

2012-01-01

Full Text Available Programmed ribosomal frameshifting (PRF serves as an intrinsic translational regulation mechanism employed by some viruses to control the ratio between structural and enzymatic proteins. Most viral mRNAs which use PRF adapt an H-type pseudoknot to stimulate −1 PRF. The relationship between the thermodynamic stability and the frameshifting efficiency of pseudoknots has not been fully understood. Recently, single-molecule force spectroscopy has revealed that the frequency of −1 PRF correlates with the unwinding forces required for disrupting pseudoknots, and that some of the unwinding work dissipates irreversibly due to the torsional restraint of pseudoknots. Complementary to single-molecule techniques, computational modeling provides insights into global motions of the ribosome, whose structural transitions during frameshifting have not yet been elucidated in atomic detail. Taken together, recent advances in biophysical tools may help to develop antiviral therapies that target the ubiquitous −1 PRF mechanism among viruses.

Polarization-dependent Imaging Contrast (PIC) mapping reveals nanocrystal orientation patterns in carbonate biominerals

Energy Technology Data Exchange (ETDEWEB)

Gilbert, Pupa U.P.A., E-mail: pupa@physics.wisc.edu [University of Wisconsin-Madison, Departments of Physics and Chemistry, Madison, WI 53706 (United States)

2012-10-15

Highlights: Black-Right-Pointing-Pointer Nanocrystal orientation shown by Polarization-dependent Imaging Contrast (PIC) maps. Black-Right-Pointing-Pointer PIC-mapping of carbonate biominerals reveals their ultrastructure at the nanoscale. Black-Right-Pointing-Pointer The formation mechanisms of biominerals is discovered by PIC-mapping using PEEM. -- Abstract: Carbonate biominerals are one of the most interesting systems a physicist can study. They play a major role in the CO{sub 2} cycle, they master templation, self-assembly, nanofabrication, phase transitions, space filling, crystal nucleation and growth mechanisms. A new imaging modality was introduced in the last 5 years that enables direct observation of the orientation of carbonate single crystals, at the nano- and micro-scale. This is Polarization-dependent Imaging Contrast (PIC) mapping, which is based on X-ray linear dichroism, and uses PhotoElectron Emission spectroMicroscopy (PEEM). Here we present PIC-mapping results from biominerals, including the nacre and prismatic layers of mollusk shells, and sea urchin teeth. We describe various PIC-mapping approaches, and show that these lead to fundamental discoveries on the formation mechanisms of biominerals.

Fundamental mechanisms of telomerase action in yeasts and mammals: understanding telomeres and telomerase in cancer cells.

Science.gov (United States)

Armstrong, Christine A; Tomita, Kazunori

2017-03-01

Aberrant activation of telomerase occurs in 85-90% of all cancers and underpins the ability of cancer cells to bypass their proliferative limit, rendering them immortal. The activity of telomerase is tightly controlled at multiple levels, from transcriptional regulation of the telomerase components to holoenzyme biogenesis and recruitment to the telomere, and finally activation and processivity. However, studies using cancer cell lines and other model systems have begun to reveal features of telomeres and telomerase that are unique to cancer. This review summarizes our current knowledge on the mechanisms of telomerase recruitment and activation using insights from studies in mammals and budding and fission yeasts. Finally, we discuss the differences in telomere homeostasis between normal cells and cancer cells, which may provide a foundation for telomere/telomerase targeted cancer treatments. © 2017 The Authors.

Recent additions to fundament aspects of quantum mechanics

International Nuclear Information System (INIS)

Flamm, D.

1991-01-01

Problems like those of Schroedinger's can comprise quantum systems as classical systems, the measurement process and reality. After a reviewing the history of interpretation of quantum mechanics it is shown how a generalized algebraic quantum theory (e.g. G.G. Emch 1986) can tackle these problems and paradoxes. This theory treats systems with infinite degrees of freedom and open systems. It is applicable both to quantum as to classical systems and thus to the measurement process with its irreversibility. The usual linear Schroedinger equation is replaced by a non-linear one where the nonlinear terms reflect the interaction of the system with its environment or with the measuring apparatus. (Quittner) To appear also in 'Naturwissenschaft und Weltbild', 1992

Demand effects of consumers’ stated and revealed preferences

OpenAIRE

Engström, Per; Forsell, Eskil

2013-01-01

Knowledge of how consumers react to different quality signals is fundamental for understanding how markets work. We study the online market- place for Android apps where we compare the causal effects on demand from two quality related signals; other consumers' stated and revealed preferences toward an app. Our main result is that consumers are much more responsive to other consumers' revealed preferences, compared to others' stated preferences. A 10 percentile increase in displayed average ra...

Convergent and divergent pathways decoding hierarchical additive mechanisms in treating cerebral ischemia-reperfusion injury.

Science.gov (United States)

Zhang, Ying-Ying; Li, Hai-Xia; Chen, Yin-Ying; Fang, Hong; Yu, Ya-Nan; Liu, Jun; Jing, Zhi-Wei; Wang, Zhong; Wang, Yong-Yan

2014-03-01

Cerebral ischemia is considered to be a highly complex disease resulting from the complicated interplay of multiple pathways. Disappointedly, most of the previous studies were limited to a single gene or a single pathway. The extent to which all involved pathways are translated into fusing mechanisms of a combination therapy is of fundamental importance. We report an integrative strategy to reveal the additive mechanism that a combination (BJ) of compound baicalin (BA) and jasminoidin (JA) fights against cerebral ischemia based on variation of pathways and functional communities. We identified six pathways of BJ group that shared diverse additive index from 0.09 to 1, which assembled broad cross talks from seven pathways of BA and 16 pathways of JA both at horizontal and vertical levels. Besides a total of 60 overlapping functions as a robust integration background among the three groups based on significantly differential subnetworks, additive mechanism with strong confidence by networks altered functions. These results provide strong evidence that the additive mechanism is more complex than previously appreciated, and an integrative analysis of pathways may suggest an important paradigm for revealing pharmacological mechanisms underlying drug combinations. © 2013 John Wiley & Sons Ltd.

Fundamental Fluid Mechanics

Indian Academy of Sciences (India)

It would also have been useful to demonstrate the application of unsteady Bernoulli equation with simple examples. There is a large. On the whole, I strongly recommend these as text books for undergraduate engineering students at the beginner's level. ______ ,AA~AAA __ ------. 88 ..., V V V V"". RESONANCE I Augustl996 ...

Dynamic mechanical oscillations during metamorphosis of the monarch butterfly

Science.gov (United States)

Pelling, Andrew E; Wilkinson, Paul R; Stringer, Richard; Gimzewski, James K

2008-01-01

The mechanical oscillation of the heart is fundamental during insect metamorphosis, but it is unclear how morphological changes affect its mechanical dynamics. Here, the micromechanical heartbeat with the monarch chrysalis (Danaus plexippus) during metamorphosis is compared with the structural changes observed through in vivo magnetic resonance imaging (MRI). We employ a novel ultra-sensitive detection approach, optical beam deflection, in order to measure the microscale motions of the pupae during the course of metamorphosis. We observed very distinct mechanical contractions occurring at regular intervals, which we ascribe to the mechanical function of the heart organ. Motion was observed to occur in approximately 15 min bursts of activity with frequencies in the 0.4–1.0 Hz range separated by periods of quiescence during the first 83 per cent of development. In the final stages, the beating was found to be uninterrupted until the adult monarch butterfly emerged. Distinct stages of development were characterized by changes in frequency, amplitude, mechanical quality factor and de/repolarization times of the mechanical pulsing. The MRI revealed that the heart organ remains functionally intact throughout metamorphosis but undergoes morphological changes that are reflected in the mechanical oscillation. PMID:18682363

Information security fundamentals

CERN Document Server

Peltier, Thomas R

2013-01-01

Developing an information security program that adheres to the principle of security as a business enabler must be the first step in an enterprise's effort to build an effective security program. Following in the footsteps of its bestselling predecessor, Information Security Fundamentals, Second Edition provides information security professionals with a clear understanding of the fundamentals of security required to address the range of issues they will experience in the field.The book examines the elements of computer security, employee roles and r

Fundamentals of statistics

CERN Document Server

Mulholland, Henry

1968-01-01

Fundamentals of Statistics covers topics on the introduction, fundamentals, and science of statistics. The book discusses the collection, organization and representation of numerical data; elementary probability; the binomial Poisson distributions; and the measures of central tendency. The text describes measures of dispersion for measuring the spread of a distribution; continuous distributions for measuring on a continuous scale; the properties and use of normal distribution; and tests involving the normal or student's 't' distributions. The use of control charts for sample means; the ranges

Two-phase systems. Fundamentals and industrial applications

International Nuclear Information System (INIS)

Woillez, Jacques

2014-01-01

Two-phase flows are omnipresent in industrial processes in different sectors with the behaviour and control of non-mixing mixtures of gas and liquids, of several liquids, of solids and fluids which are present in the production of raw materials, in the environment, in energy production, in chemistry, in pharmaceutical or food industry. The author presents the fundamentals elements which are needed to perform hardware predictive calculations and to understand typical phenomena associated with these flows. The chapters address fluids mechanics (movement equations, Bernoulli equation, load losses, turbulence, heat exchange coefficients, thermodynamics, compressible flows), two-phase systems (characteristic values, modes of appearance of two-phase flows, conduct flows, suspension mechanics, mass transfers, similarity, numerical simulation), the applications (energy production, agitation and mixing, phase separation, sprays), and peculiar phenomena (Marangoni effect, the tea cup effect, entry jets, water hammer effect, sound speed, two-phase pumping, fluidization)

Fundamentals of tribology at the atomic level

Science.gov (United States)

Ferrante, John; Pepper, Stephen V.

1989-01-01

Tribology, the science and engineering of solid surfaces in moving contact, is a field that encompasses many disciplines: solid state physics, chemistry, materials science, and mechanical engineering. In spite of the practical importance and maturity of the field, the fundamental understanding of basic phenomena has only recently been attacked. An attempt to define some of these problems and indicate some profitable directions for future research is presented. There are three broad classifications: (1) fluid properties (compression, rheology, additives and particulates); (2) material properties of the solids (deformation, defect formation and energy loss mechanisms); and (3) interfacial properties (adhesion, friction chemical reactions, and boundary films). Research in the categories has traditionally been approached by considering macroscopic material properties. Recent activity has shown that some issues can be approached at the atomic level: the atoms in the materials can be manipulated both experimentally and theoretically, and can produce results related to macroscopic phenomena.

Fundamentals of fast reduction of ultrafine iron ore at low temperature

Institute of Scientific and Technical Information of China (English)

Pei Zhao; Peimin Guo

2008-01-01

Fundamentals on the fast reduction of ultrafine iron ore at low temperature, including characterization of ultrafine ore, de- oxidation thermodynamics of stored-energy ultrafine ore, kinetics of iron ore deoxidation, and deoxidation mechanism, etc., and a new ironmaking process are presented in this article. Ultrafine ore concentrate with a high amount of stored energy can be produced by mechanical milling, and can be dcoxidated fast below 700℃ by either the coal-based or gas-based process. This novel process has some advantages over others: high productivity, low energy consumption, and environmental friendliness.

Fundamental burn-up mode in a pebble-bed type reactor

International Nuclear Information System (INIS)

Chen, Xue-Nong; Kiefhaber, Edgar; Maschek, Werner

2008-01-01

This paper deals with a pebble-bed type reactor, in which the fuel is loaded from one side (top) and discharged from the other side (bottom). A boundary value problem of a single group diffusion equation coupled with simplified burn-up equations is studied, where the natural radioactive decay processes are neglected in the burn-up modelling. An asymptotic burning wave solution is found analytically in the one-dimensional case, which is called as fundamental burn-up mode. Among this solution family there are two particular cases, namely, a classic fundamental solution with a zero burn-up and a partial solitary burn-up wave solution with a highest burn-up. An example of Th-U conversion is considered and the solutions are presented in order to show the mechanism of the burning wave. (author)

3D microelectronic packaging from fundamentals to applications

CERN Document Server

Goyal, Deepak

2017-01-01

This volume provides a comprehensive reference for graduate students and professionals in both academia and industry on the fundamentals, processing details, and applications of 3D microelectronic packaging, an industry trend for future microelectronic packages. Chapters written by experts cover the most recent research results and industry progress in the following areas: TSV, die processing, micro bumps, direct bonding, thermal compression bonding, advanced materials, heat dissipation, thermal management, thermal mechanical modeling, quality, reliability, fault isolation, and failure analysis of 3D microelectronic packages. Numerous images, tables, and didactic schematics are included throughout. This essential volume equips readers with an in-depth understanding of all aspects of 3D packaging, including packaging architecture, processing, thermal mechanical and moisture related reliability concerns, common failures, developing areas, and future challenges, providing insights into key areas for future resea...

Continuum Mechanics

CERN Document Server

Romano, Antonio

2010-01-01

This book offers a broad overview of the potential of continuum mechanics to describe a wide range of macroscopic phenomena in real-world problems. Building on the fundamentals presented in the authors' previous book, Continuum Mechanics using Mathematica(R), this new work explores interesting models of continuum mechanics, with an emphasis on exploring the flexibility of their applications in a wide variety of fields.Specific topics, which have been chosen to show the power of continuum mechanics to characterize the experimental behavior of real phenomena, include: * various aspects of nonlin

Infosec management fundamentals

CERN Document Server

Dalziel, Henry

2015-01-01

Infosec Management Fundamentals is a concise overview of the Information Security management concepts and techniques, providing a foundational template for both experienced professionals and those new to the industry. This brief volume will also appeal to business executives and managers outside of infosec who want to understand the fundamental concepts of Information Security and how it impacts their business decisions and daily activities. Teaches ISO/IEC 27000 best practices on information security management Discusses risks and controls within the context of an overall information securi

Phenotype specific analyses reveal distinct regulatory mechanism for chronically activated p53.

Directory of Open Access Journals (Sweden)

Kristina Kirschner

2015-03-01

Full Text Available The downstream functions of the DNA binding tumor suppressor p53 vary depending on the cellular context, and persistent p53 activation has recently been implicated in tumor suppression and senescence. However, genome-wide information about p53-target gene regulation has been derived mostly from acute genotoxic conditions. Using ChIP-seq and expression data, we have found distinct p53 binding profiles between acutely activated (through DNA damage and chronically activated (in senescent or pro-apoptotic conditions p53. Compared to the classical 'acute' p53 binding profile, 'chronic' p53 peaks were closely associated with CpG-islands. Furthermore, the chronic CpG-island binding of p53 conferred distinct expression patterns between senescent and pro-apoptotic conditions. Using the p53 targets seen in the chronic conditions together with external high-throughput datasets, we have built p53 networks that revealed extensive self-regulatory 'p53 hubs' where p53 and many p53 targets can physically interact with each other. Integrating these results with public clinical datasets identified the cancer-associated lipogenic enzyme, SCD, which we found to be directly repressed by p53 through the CpG-island promoter, providing a mechanistic link between p53 and the 'lipogenic phenotype', a hallmark of cancer. Our data reveal distinct phenotype associations of chronic p53 targets that underlie specific gene regulatory mechanisms.

Fundamental length

International Nuclear Information System (INIS)

Pradhan, T.

1975-01-01

The concept of fundamental length was first put forward by Heisenberg from purely dimensional reasons. From a study of the observed masses of the elementary particles known at that time, it is sumrised that this length should be of the order of magnitude 1 approximately 10 -13 cm. It was Heisenberg's belief that introduction of such a fundamental length would eliminate the divergence difficulties from relativistic quantum field theory by cutting off the high energy regions of the 'proper fields'. Since the divergence difficulties arise primarily due to infinite number of degrees of freedom, one simple remedy would be the introduction of a principle that limits these degrees of freedom by removing the effectiveness of the waves with a frequency exceeding a certain limit without destroying the relativistic invariance of the theory. The principle can be stated as follows: It is in principle impossible to invent an experiment of any kind that will permit a distintion between the positions of two particles at rest, the distance between which is below a certain limit. A more elegant way of introducing fundamental length into quantum theory is through commutation relations between two position operators. In quantum field theory such as quantum electrodynamics, it can be introduced through the commutation relation between two interpolating photon fields (vector potentials). (K.B.)

What Protein Charging (and Supercharging) Reveal about the Mechanism of Electrospray Ionization

Science.gov (United States)

Ogorzalek Loo, Rachel R.; Lakshmanan, Rajeswari; Loo, Joseph A.

2014-10-01

Understanding the charging mechanism of electrospray ionization is central to overcoming shortcomings such as ion suppression or limited dynamic range, and explaining phenomena such as supercharging. Towards that end, we explore what accumulated observations reveal about the mechanism of electrospray. We introduce the idea of an intermediate region for electrospray ionization (and other ionization methods) to account for the facts that solution charge state distributions (CSDs) do not correlate with those observed by ESI-MS (the latter bear more charge) and that gas phase reactions can reduce, but not increase, the extent of charging. This region incorporates properties (e.g., basicities) intermediate between solution and gas phase. Assuming that droplet species polarize within the high electric field leads to equations describing ion emission resembling those from the equilibrium partitioning model. The equations predict many trends successfully, including CSD shifts to higher m/z for concentrated analytes and shifts to lower m/z for sprays employing smaller emitter opening diameters. From this view, a single mechanism can be formulated to explain how reagents that promote analyte charging ("supercharging") such as m-NBA, sulfolane, and 3-nitrobenzonitrile increase analyte charge from "denaturing" and "native" solvent systems. It is suggested that additives' Brønsted basicities are inversely correlated to their ability to shift CSDs to lower m/z in positive ESI, as are Brønsted acidities for negative ESI. Because supercharging agents reduce an analyte's solution ionization, excess spray charge is bestowed on evaporating ions carrying fewer opposing charges. Brønsted basicity (or acidity) determines how much ESI charge is lost to the agent (unavailable to evaporating analyte).

Fundamental size limitations of micro four-point probes

DEFF Research Database (Denmark)

Ansbæk, Thor; Petersen, Dirch Hjorth; Hansen, Ole

2009-01-01

The continued down-scaling of integrated circuits and magnetic tunnel junctions (MTJ) for hard disc read heads presents a challenge to current metrology technology. The four-point probes (4PP), currently used for sheet resistance characterization in these applications, therefore must be down......-scaled as well in order to correctly characterize the extremely thin films used. This presents a four-point probe design and fabrication challenge. We analyze the fundamental limitation on down-scaling of a generic micro four-point probe (M4PP) in a comprehensive study, where mechanical, thermal, and electrical...

To the field theory with a fundamental mass

International Nuclear Information System (INIS)

Ibadov, R.M.; Kadyshevskij, V.G.

1986-01-01

This paper is a continuation of the investigations along the lines of constructing a consistent field theory with fundamental mass M - a hypothetical universal scale in the ultrahigh energy region. Earlier, in the developed approach the key role was played by the de Sitter momentum space of radius M. In this paper a quantum version of this idea is worked out: p-space is assumed to be a de Sitter one like before; however, the four-momentum p μ is treated as a quantum mechanical operator in δ/δx μ only

The Impact of Fundamental and Financial Traders on the Term Structure of Oil

DEFF Research Database (Denmark)

Heidorn, Thomas; Mokinski, Frieder; Rühl, Christof

2015-01-01

We study how the exposure of fundamental and financial traders affects the futures curve of WTI oil and the market integration between WTI and Brent measured by their price spread. To obtain a parsimonious representation of the futures curve, we decompose it into a level-, a slope- and a curvature...... factor in a first step. In a second step, we separately regress each extracted factor on measures of the market exposure of fundamental and financial traders revealing whether and how the exposure of the two trader groups affects the different dimensions of the futures curve. Spanning from 2006 until...... 2012, our dataset covers sub-periods of a sharp WTI-price rise as well as a diverging Brent-WTI-spread. Our contribution is threefold: First, we suggest that it is important to distinguish between level and slope as we find that fundamental traders have a measurable impact on the level of the futures...

To love or hate thy neighbor : The role of authoritarianism and traditionalism in explaining the link between fundamentalism and racial prejudice

NARCIS (Netherlands)

Brandt, M.J.; Reyna, C.

2014-01-01

Fundamentalism is consistently related to racial prejudice (Hall, Matz, & Wood, 2010), yet the mechanisms for this relationship are unclear. We identify two core values of fundamentalism, authoritarianism and traditionalism, that independently contribute to the fundamentalism‐racial prejudice

Laser-induced plasmas as an analytical source for quantitative analysis of gaseous and aerosol systems: Fundamentals of plasma-particle interactions

Science.gov (United States)

Diwakar, Prasoon K.

2009-11-01

Laser-induced Breakdown Spectroscopy (LIBS) is a relatively new analytical diagnostic technique which has gained serious attention in recent past due to its simplicity, robustness, and portability and multi-element analysis capabilities. LIBS has been used successfully for analysis of elements in different media including solids, liquids and gases. Since 1963, when the first breakdown study was reported, to 1983, when the first LIBS experiments were reported, the technique has come a long way, but the majority of fundamental understanding of the processes that occur has taken place in last few years, which has propelled LIBS in the direction of being a well established analytical technique. This study, which mostly focuses on LIBS involving aerosols, has been able to unravel some of the mysteries and provide knowledge that will be valuable to LIBS community as a whole. LIBS processes can be broken down to three basic steps, namely, plasma formation, analyte introduction, and plasma-analyte interactions. In this study, these three steps have been investigated in laser-induced plasma, focusing mainly on the plasma-particle interactions. Understanding plasma-particle interactions and the fundamental processes involved is important in advancing laser-induced breakdown spectroscopy as a reliable and accurate analytical technique. Critical understanding of plasma-particle interactions includes study of the plasma evolution, analyte atomization, and the particle dissociation and diffusion. In this dissertation, temporal and spatial studies have been done to understand the fundamentals of the LIBS processes including the breakdown of gases by the laser pulse, plasma inception mechanisms, plasma evolution, analyte introduction and plasma-particle interactions and their influence on LIBS signal. Spectral measurements were performed in a laser-induced plasma and the results reveal localized perturbations in the plasma properties in the vicinity of the analyte species, for

Fundamentals of ergonomic exoskeleton robots

OpenAIRE

Schiele, A.

2008-01-01

This thesis is the first to provide the fundamentals of ergonomic exoskeleton design. The fundamental theory as well as technology necessary to analyze and develop ergonomic wearable robots interacting with humans is established and validated by experiments and prototypes. The fundamentals are (1) a new theoretical framework for analyzing physical human robot interaction (pHRI) with exoskeletons, and (2) a clear set of design rules of how to build wearable, portable exoskeletons to easily and...

Fundamental degradation mechanisms of layered oxide Li-ion battery cathode materials: Methodology, insights and novel approaches

International Nuclear Information System (INIS)

Hausbrand, R.; Cherkashinin, G.; Ehrenberg, H.; Gröting, M.; Albe, K.; Hess, C.; Jaegermann, W.

2015-01-01

Graphical abstract: - Highlights: • Description of recent in operando and in situ analysis methodology. • Surface science approach using photoemission for analysis of cathode surfaces and interfaces. • Ageing and fatigue of layered oxide Li-ion battery cathode materials from the atomistic point of view. • Defect formation and electronic structure evolution as causes for cathode degradation. • Significance of interfacial energy alignment and contact potential for side reactions. - Abstract: This overview addresses the atomistic aspects of degradation of layered LiMO 2 (M = Ni, Co, Mn) oxide Li-ion battery cathode materials, aiming to shed light on the fundamental degradation mechanisms especially inside active cathode materials and at their interfaces. It includes recent results obtained by novel in situ/in operando diffraction methods, modelling, and quasi in situ surface science analysis. Degradation of the active cathode material occurs upon overcharge, resulting from a positive potential shift of the anode. Oxygen loss and eventual phase transformation resulting in dead regions are ascribed to changes in electronic structure and defect formation. The anode potential shift results from loss of free lithium due to side reactions occurring at electrode/electrolyte interfaces. Such side reactions are caused by electron transfer, and depend on the electron energy level alignment at the interface. Side reactions at electrode/electrolyte interfaces and capacity fade may be overcome by the use of suitable solid-state electrolytes and Li-containing anodes

Mechanisms of Evolution in High-Consequence Drug Resistance Plasmids

Directory of Open Access Journals (Sweden)

Susu He

2016-12-01

Full Text Available The dissemination of resistance among bacteria has been facilitated by the fact that resistance genes are usually located on a diverse and evolving set of transmissible plasmids. However, the mechanisms generating diversity and enabling adaptation within highly successful resistance plasmids have remained obscure, despite their profound clinical significance. To understand these mechanisms, we have performed a detailed analysis of the mobilome (the entire mobile genetic element content of a set of previously sequenced carbapenemase-producing Enterobacteriaceae (CPE from the National Institutes of Health Clinical Center. This analysis revealed that plasmid reorganizations occurring in the natural context of colonization of human hosts were overwhelmingly driven by genetic rearrangements carried out by replicative transposons working in concert with the process of homologous recombination. A more complete understanding of the molecular mechanisms and evolutionary forces driving rearrangements in resistance plasmids may lead to fundamentally new strategies to address the problem of antibiotic resistance.

A educação como um direito fundamental de natureza social Education as a fundamental right of social nature

Directory of Open Access Journals (Sweden)

Clarice Seixas Duarte

2007-10-01

Full Text Available Parece haver consenso em torno da idéia de que a educação deve ser tratada como uma prioridade por nossos governantes. Contudo, a realidade demonstra que a educação escolar de qualidade ainda é um sonho distante, sobretudo para os setores mais vulneráveis de nossa sociedade. Poucos sabem quais as implicações práticas da enunciação, em nossa Constituição, do direito à educação como um direito fundamental de natureza social e, conseqüentemente, o que pode ser exigido do Estado para a sua satisfação. Quem são os titulares desse direito? Ele pode ser exigido coletivamente? Abrange apenas uma vaga no ensino fundamental ou o direito à realização de uma política pública? Há mecanismos jurídicos que podem ser acionados em caso de sua oferta irregular ou insuficiente? O desafio desse artigo é delinear o regime jurídico de proteção do direito à educação como um direito fundamental de natureza social, buscando, com isso, contribuir para a ampliação das possibilidades concretas de sua realização.There seems to be a consensus on the idea that our government should consider education as a priority. However, reality shows that education is still a distant dream, especially for the most vulnerable groups in our society. Both the practical implications of the fact that our Constitution states the right to education as a fundamental right of social nature and the requirements that can be addressed to the State to meet it are little known. Who is benefited by such right? May it be demanded collectively? Does it only mean a seat in an elementary school or the right to require public policies? May legal mechanisms be used in case of irregular or inadequate offer? The challenge of this article is to define the legal regime of the right to education as a fundamental right of social nature to contribute to increase the concrete possibilities for its satisfaction.

Epitope-dependent mechanisms of CD27 neutralization revealed by X-ray crystallography

Energy Technology Data Exchange (ETDEWEB)

Obmolova, Galina; Teplyakov, Alexey; Malia, Thomas J.; Wunderler, Nicole; Kwok, Deborah; Barone, Linda; Sweet, Raymond; Ort, Tatiana; Scully, Michael; Gilliland, Gary L. (Janssen)

2017-03-01

CD27 is a T and B cell co-stimulatory protein of the TNF receptor superfamily dependent on the availability of the TNF-like ligand CD70. Two anti-CD27 neutralizing monoclonal antibodies were obtained from mouse hybridoma and subsequently humanized and optimized for binding the target. The two antibodies are similar in terms of their CD27-binding affinity and ability to block NF-κB signaling, however their clearance rates in monkeys are very different. The pharmacokinetics profiles could be epitope dependent. To identify the epitopes, we determined the crystal structure of the ternary complex between CD27 and the Fab fragments of these non-competing antibodies. The structure reveals the binding modes of the antibodies suggesting that their mechanisms of action are distinctly different and provides a possible explanation of the in vivo data.

Measurement theory in quantum mechanics

International Nuclear Information System (INIS)

Klein, G.

1980-01-01

It is assumed that consciousness, memory and liberty (within the limits of the quantum mechanics indeterminism) are fundamental properties of elementary particles. Then, using this assumption it is shown how measurements and observers may be introduced in a natural way in the quantum mechanics theory. There are no longer fundamental differences between macroscopic and microscopic objects, between classical and quantum objects, between observer and object. Thus, discrepancies and paradoxes have disappeared from the conventional quantum mechanics theory. One consequence of the cumulative memory of the particles is that the sum of negentropy plus information is a constant. Using this theory it is also possible to explain the 'paranormal' phenomena and what is their difference from the 'normal' ones [fr

Towards an axiomatic model of fundamental interactions at Planck scale

OpenAIRE

Kiselev, Arthemy V.

2014-01-01

By exploring possible physical sense of notions, structures, and logic in a class of noncommutative geometries, we try to unify the four fundamental interactions within an axiomatic quantum picture. We identify the objects and algebraic operations which could properly encode the formation and structure of sub-atomic particles, antimatter, annihilation, CP-symmetry violation, mass endowment mechanism, three lepton-neutrino matchings, spin, helicity and chirality, electric charge and electromag...

``From Fundamental Motives to Rational Expectation Equilibrium[REE, henceworth] of Indeterminacy''

Science.gov (United States)

Maksoed, Ssi, Wh-

For ``Principle of Indeterminacy''from Heisenberg states: ``one of the fundamental cornerstone of quantum mechanics is the Heisenberg uncertainty principle''.whereas canonically conjugate quantities can be determined simultaneously only with a characteristic indeterminacy[M. Arevalo Aguilar, et.al]. Accompanying Alfred North Whitehead conclusion in ``The Aims of Education''that mathematical symbols are artificial before new meanings given, two kinds of fundamental motives: (i) expectation-expectation, (ii) expectation-certainty inherently occurs with determinacy properties of rational expectation equilibrium(REE, henceworth)- Guido Ascari & Tizano Ropele:''Trend inflation, Taylor principle & Indeterminacy'', Kiel Institute, June 2007. Furthers, relative price expression can be compare of their α and (1 - α) configurations in the expression of possible activity. Acknowledgment to Prof[asc]. Dr. Bobby Eka Gunara for ``made a rank through physics'' denotes...

Mechanism of the superior mechanical strength of nanometer-sized metal single crystals revealed

KAUST Repository

Afify, N. D.; Salem, H. G.; Yavari, A.; El Sayed, Tamer S.

2013-01-01

Clear understanding of the superior mechanical strength of nanometer-sized metal single crystals is required to derive advanced mechanical components retaining such superiority. Although high quality studies have been reported on nano

Communication technology update and fundamentals

CERN Document Server

Grant, August E

2010-01-01

New communication technologies are being introduced at an astonishing rate. Making sense of these technologies is increasingly difficult. Communication Technology Update and Fundamentals is the single best source for the latest developments, trends, and issues in communication technology. Featuring the fundamental framework along with the history and background of communication technologies, Communication Technology Update and Fundamentals, 12th edition helps you stay ahead of these ever-changing and emerging technologies.As always, every chapter ha

About Fundamental Problems of Hydrosphere and Silicate Karst

Directory of Open Access Journals (Sweden)

A. Ya. Gayev

2017-09-01

Full Text Available Rationale of hydrosphere model with two regions of supply and discharge reveals regularities of ground water formation reflecting the special features of system water – rock – gas – living material and character of interaction of hydrosphere with the other spheres of the Earth. It is necessary to concentrate the development of endogenous hy-drogeology fundamentals with the study of silicate karst on investigation of “white and black smokers”, the structure and isotope composition of water in different phase condi-tions, and on modeling of situation in hydrometagenese zone. It will support the development of geotechnology and providing the humanity with mineral and energetic resources in future.

The fundamentals of atomic and molecular physics

CERN Document Server

Brooks, Robert L

2013-01-01

The Fundamentals of Atomic and Molecular Physics is intended as an introduction to the field for advanced undergraduates who have taken quantum mechanics. Each chapter builds upon the previous, using the same tools and methods throughout. As the students progress through the book, their ability to use these tools will steadily increase, along with their confidence in their efficacy. The book treats the two-electron atom as the simplest example of the many-electron atom—as opposed to using techniques that are not applicable to many-electron atoms—so that it is unnecessary to develop additional equations when turning to multielectron atoms, such as carbon. External fields are treated using both perturbation theory and direct diagonalization and spontaneous emission is developed from first principles. Only diatomic molecules are considered with the hydrogen molecular ion and neutral molecule treated in some detail. This comprehensive coverage of the quantum mechanics of complex atoms and simple diatomic mole...

Individual differences in fundamental social motives.

Science.gov (United States)

Neel, Rebecca; Kenrick, Douglas T; White, Andrew Edward; Neuberg, Steven L

2016-06-01

Motivation has long been recognized as an important component of how people both differ from, and are similar to, each other. The current research applies the biologically grounded fundamental social motives framework, which assumes that human motivational systems are functionally shaped to manage the major costs and benefits of social life, to understand individual differences in social motives. Using the Fundamental Social Motives Inventory, we explore the relations among the different fundamental social motives of Self-Protection, Disease Avoidance, Affiliation, Status, Mate Seeking, Mate Retention, and Kin Care; the relationships of the fundamental social motives to other individual difference and personality measures including the Big Five personality traits; the extent to which fundamental social motives are linked to recent life experiences; and the extent to which life history variables (e.g., age, sex, childhood environment) predict individual differences in the fundamental social motives. Results suggest that the fundamental social motives are a powerful lens through which to examine individual differences: They are grounded in theory, have explanatory value beyond that of the Big Five personality traits, and vary meaningfully with a number of life history variables. A fundamental social motives approach provides a generative framework for considering the meaning and implications of individual differences in social motivation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Micro-Plasto-Hydrodynamic Lubrication a Fundamental Mechanism in Cold Rolling

DEFF Research Database (Denmark)

Laugier, Maxime; Boman, Romain; Legrand, Nicolas

2014-01-01

This paper presents recent investigations in Micro-Plasto-Hydrodynamic (MPH) lubrication. Industrial evidences of the existence of MPH lubrication mechanism for cold rolling processes are presented. A new lubrication model developed for strip drawing processes is then applied to predict the MPH...

A Case for the Need of Using Scaffolding Methods in Teaching Introductory, Fundamental Engineering Mechanics Classes

Science.gov (United States)

Boylan-Ashraf, Peggy C.; Freeman, Steven A.; Shelley, Mack C.

2015-01-01

In the past ten years, engineering classrooms have seen an exponential growth in the use of technology, more than during any other previous decade. Unprecedented advancements, such as the advent of innovative gadgets and fundamental instructional alterations in engineering classrooms, have introduced changes in both teaching and learning. Student…

Teaching the Politics of Islamic Fundamentalism.

Science.gov (United States)

Kazemzadeh, Masoud

1998-01-01

Argues that the rise of Islamic fundamentalism since the Iranian Revolution has generated a number of issues of analytical significance for political science. Describes three main models in teaching and research on Islamic fundamentalism: Islamic exceptionalism, comparative fundamentalisms, and class analysis. Discusses the construction of a…

Fundamental principles of heat transfer

CERN Document Server

Whitaker, Stephen

1977-01-01

Fundamental Principles of Heat Transfer introduces the fundamental concepts of heat transfer: conduction, convection, and radiation. It presents theoretical developments and example and design problems and illustrates the practical applications of fundamental principles. The chapters in this book cover various topics such as one-dimensional and transient heat conduction, energy and turbulent transport, forced convection, thermal radiation, and radiant energy exchange. There are example problems and solutions at the end of every chapter dealing with design problems. This book is a valuable int

pH Effects in Foods: Development, Validation and Calibration of a Fundamental Model

NARCIS (Netherlands)

Tijskens, L.M.M.; Biekman, E.S.A.; Greiner, R.; Seyhan, F.; Barringer, S.A.

2001-01-01

The effects of pH observed in the activity of a number of enzymes from different origins and the degradation of green colour in blanched vegetables, was modelled based on fundamental kinetic principles by considering hydrogen ions as an integral part of the reaction mechanism. Parameters were

Fundamental Astronomy

CERN Document Server

Karttunen, Hannu; Oja, Heikki; Poutanen, Markku; Donner, Karl Johan

2007-01-01

Fundamental Astronomy gives a well-balanced and comprehensive introduction to the topics of classical and modern astronomy. While emphasizing both the astronomical concepts and the underlying physical principles, the text provides a sound basis for more profound studies in the astronomical sciences. The fifth edition of this successful undergraduate textbook has been extensively modernized and extended in the parts dealing with the Milky Way, extragalactic astronomy and cosmology as well as with extrasolar planets and the solar system (as a consequence of recent results from satellite missions and the new definition by the International Astronomical Union of planets, dwarf planets and small solar-system bodies). Furthermore a new chapter on astrobiology has been added. Long considered a standard text for physical science majors, Fundamental Astronomy is also an excellent reference and entrée for dedicated amateur astronomers.

Robot Mechanisms

CERN Document Server

Lenarcic, Jadran; Stanišić, Michael M

2013-01-01

This book provides a comprehensive introduction to the area of robot mechanisms, primarily considering industrial manipulators and humanoid arms. The book is intended for both teaching and self-study. Emphasis is given to the fundamentals of kinematic analysis and the design of robot mechanisms. The coverage of topics is untypical. The focus is on robot kinematics. The book creates a balance between theoretical and practical aspects in the development and application of robot mechanisms, and includes the latest achievements and trends in robot science and technology.

Elastoviscous Transitions of Articular Cartilage Reveal a Mechanism of Synergy between Lubricin and Hyaluronic Acid.

Directory of Open Access Journals (Sweden)

Edward D Bonnevie

Full Text Available When lubricated by synovial fluid, articular cartilage provides some of the lowest friction coefficients found in nature. While it is known that macromolecular constituents of synovial fluid provide it with its lubricating ability, it is not fully understood how two of the main molecules, lubricin and hyaluronic acid, lubricate and interact with one another. Here, we develop a novel framework for cartilage lubrication based on the elastoviscous transition to show that lubricin and hyaluronic acid lubricate by distinct mechanisms. Such analysis revealed nonspecific interactions between these molecules in which lubricin acts to concentrate hyaluronic acid near the tissue surface and promotes a transition to a low friction regime consistent with the theory of viscous boundary lubrication. Understanding the mechanics of synovial fluid not only provides insight into the progression of diseases such as arthritis, but also may be applicable to the development of new biomimetic lubricants.

Fundamental Mechanisms of Roughening and Smoothing During Thin Film Deposition

Energy Technology Data Exchange (ETDEWEB)

Headrick, Randall [Univ. of Vermont, Burlington, VT (United States)

2016-03-18

In this research program, we have explored the fundamental limits for thin film deposition in both crystalline and amorphous (i.e. non-crystalline) materials systems. For vacuum-based physical deposition processes such as sputter deposition, the background gas pressure of the inert gas (usually argon) used as the process gas has been found to be a key variable. Both a roughness transition and stress transition as a function of pressure have been linked to a common mechanism involving collisions of energetic particles from the deposition source with the process inert gas. As energetic particles collide with gas molecules in the deposition process they lose their energy rapidly if the pressure (and background gas density) is above a critical value. Both roughness and stress limit important properties of thin films for applications. In the area of epitaxial growth we have also discovered a related effect; there is a critical pressure below which highly crystalline layers grow in a layer-by-layer mode. This effect is also though to be due to energetic particle thermalization and scattering. Several other important effects such as the observation of coalescence dominated growth has been observed. This mode can be likened to the behavior of two-dimensional water droplets on the hood of a car during a rain storm; as the droplets grow and touch each other they tend to coalesce rapidly into new larger circular puddles, and this process proceeds exponentially as larger puddles overtake smaller ones and also merge with other large puddles. This discovery will enable more accurate simulations and modeling of epitaxial growth processes. We have also observed that epitaxial films undergo a roughening transition as a function of thickness, which is attributed to strain induced by the crystalline lattice mismatch with the substrate crystal. In addition, we have studied another physical deposition process called pulsed laser deposition. It differs from sputter deposition due to the

Trophic cascades triggered by overfishing reveal possible mechanisms of ecosystem regime shifts.

Science.gov (United States)

Daskalov, Georgi M; Grishin, Alexander N; Rodionov, Sergei; Mihneva, Vesselina

2007-06-19

Large-scale transitions between alternative states in ecosystems are known as regime shifts. Once described as healthy and dominated by various marine predators, the Black Sea ecosystem by the late 20th century had experienced anthropogenic impacts such as heavy fishing, cultural eutrophication, and invasions by alien species. We studied changes related to these "natural experiments" to reveal the mechanisms of regime shifts. Two major shifts were detected, the first related to a depletion of marine predators and the second to an outburst of the alien comb jelly Mnemiopsis leidyi; both shifts were triggered by intense fishing resulting in system-wide trophic cascades. The complex nature of ecosystem responses to human activities calls for more elaborate approaches than currently provided by traditional environmental and fisheries management. This implies challenging existing practices and implementing explanatory models of ecosystem interactions that can better reconcile conservation and ecosystem management ideals.

Evaluating fundamentals of care: The development of a unit-level quality measurement and improvement programme.

Science.gov (United States)

Parr, Jenny M; Bell, Jeanette; Koziol-McLain, Jane

2018-06-01

The project aimed to develop a unit-level quality measurement and improvement programme using evidence-based fundamentals of care. Feedback from patients, families, whānau, staff and audit data in 2014 indicated variability in the delivery of fundamental aspects of care such as monitoring, nutrition, pain management and environmental cleanliness at a New Zealand District Health Board. A general inductive approach was used to explore the fundamentals of care and design a measurement and improvement programme, the Patient and Whānau Centred Care Standards (PWCCS), focused on fundamental care. Five phases were used to explore the evidence, and design and test a measurement and improvement framework. Nine identified fundamental elements of care were used to define expected standards of care and develop and test a measurement and improvement framework. Four six-monthly peer reviews have been undertaken since June 2015. Charge Nurse Managers used results to identify quality improvements. Significant improvement was demonstrated overall, in six of the 27 units, in seven of the nine standards and three of the four measures. In all, 89% (n = 24) of units improved their overall result. The PWCCS measurement and improvement framework make visible nursing fundamentals of care in line with continuous quality improvement to increase quality of care. Delivering fundamentals of care is described by nurses as getting ?back to basics'. Patient and family feedback supports the centrality of fundamentals of care to their hospital experience. Implementing a unit-level fundamentals of care quality measurement and improvement programme clarifies expected standards of care, highlights the contribution of fundamentals of care to quality and provides a mechanism for ongoing improvements. © 2018 John Wiley & Sons Ltd.

Proteomic Analysis Reveals the Leaf Color Regulation Mechanism in Chimera Hosta "Gold Standard" Leaves.

Science.gov (United States)

Yu, Juanjuan; Zhang, Jinzheng; Zhao, Qi; Liu, Yuelu; Chen, Sixue; Guo, Hongliang; Shi, Lei; Dai, Shaojun

2016-03-08

Leaf color change of variegated leaves from chimera species is regulated by fine-tuned molecular mechanisms. Hosta "Gold Standard" is a typical chimera Hosta species with golden-green variegated leaves, which is an ideal material to investigate the molecular mechanisms of leaf variegation. In this study, the margin and center regions of young and mature leaves from Hosta "Gold Standard", as well as the leaves from plants after excess nitrogen fertilization were studied using physiological and comparative proteomic approaches. We identified 31 differentially expressed proteins in various regions and development stages of variegated leaves. Some of them may be related to the leaf color regulation in Hosta "Gold Standard". For example, cytosolic glutamine synthetase (GS1), heat shock protein 70 (Hsp70), and chloroplastic elongation factor G (cpEF-G) were involved in pigment-related nitrogen synthesis as well as protein synthesis and processing. By integrating the proteomics data with physiological results, we revealed the metabolic patterns of nitrogen metabolism, photosynthesis, energy supply, as well as chloroplast protein synthesis, import and processing in various leaf regions at different development stages. Additionally, chloroplast-localized proteoforms involved in nitrogen metabolism, photosynthesis and protein processing implied that post-translational modifications were crucial for leaf color regulation. These results provide new clues toward understanding the mechanisms of leaf color regulation in variegated leaves.

Species-Specific Mechanisms of Neuron Subtype Specification Reveal Evolutionary Plasticity of Amniote Brain Development

Directory of Open Access Journals (Sweden)

Tadashi Nomura

2018-03-01

Full Text Available Summary: Highly ordered brain architectures in vertebrates consist of multiple neuron subtypes with specific neuronal connections. However, the origin of and evolutionary changes in neuron specification mechanisms remain unclear. Here, we report that regulatory mechanisms of neuron subtype specification are divergent in developing amniote brains. In the mammalian neocortex, the transcription factors (TFs Ctip2 and Satb2 are differentially expressed in layer-specific neurons. In contrast, these TFs are co-localized in reptilian and avian dorsal pallial neurons. Multi-potential progenitors that produce distinct neuronal subtypes commonly exist in the reptilian and avian dorsal pallium, whereas a cis-regulatory element of avian Ctip2 exhibits attenuated transcription suppressive activity. Furthermore, the neuronal subtypes distinguished by these TFs are not tightly associated with conserved neuronal connections among amniotes. Our findings reveal the evolutionary plasticity of regulatory gene functions that contribute to species differences in neuronal heterogeneity and connectivity in developing amniote brains. : Neuronal heterogeneity is essential for assembling intricate neuronal circuits. Nomura et al. find that species-specific transcriptional mechanisms underlie diversities of excitatory neuron subtypes in mammalian and non-mammalian brains. Species differences in neuronal subtypes and connections suggest functional plasticity of regulatory genes for neuronal specification during amniote brain evolution. Keywords: Ctip2, Satb2, multi-potential progenitors, transcriptional regulation, neuronal connectivity

Nonlinear generation of the fundamental radiation of interplanetary type III radio bursts

International Nuclear Information System (INIS)

Chian, A.C.L.; Alves, M.V.

1988-01-01

A new generation mechanism of interplanetary type III radio bursts at the fundamental electron plasma frequency is discussed. It is shown that the electromagnetic oscillating two-stream instability, driven by two oppositely propagating Langmuir waves, can account for the experimental observations. In particular, the major difficulties encountered by the previously considered electromagnetic decay instability are removed. 19 references

Religious fundamentalism and conflict

OpenAIRE

Muzaffer Ercan Yılmaz

2006-01-01

This study provides an analytical discussion for the issue of religious fundamentalism and itsrelevance to conflict, in its broader sense. It is stressed that religious fundamentalism manifests itself in twoways: nonviolent intolerance and violent intolerance. The sources of both types of intolerance and theirconnection to conflict are addressed and discussed in detail. Further research is also suggested on conditionsconnecting religion to nonviolent intolerance so as to cope with the problem...

Response to various periods of mechanical stimuli in Physarum plasmodium

International Nuclear Information System (INIS)

Umedachi, Takuya; Ito, Kentaro; Kobayashi, Ryo; Ishiguro, Akio; Nakagaki, Toshiyuki

2017-01-01

Response to mechanical stimuli is a fundamental and critical ability for living cells to survive in hazardous conditions or to form adaptive and functional structures against force(s) from the environment. Although this ability has been extensively studied by molecular biology strategies, it is also important to investigate the ability from the viewpoint of biological rhythm phenomena so as to reveal the mechanisms that underlie these phenomena. Here, we use the plasmodium of the true slime mold Physarum polycephalum as the experimental system for investigating this ability. The plasmodium was repetitively stretched for various periods during which its locomotion speed was observed. Since the plasmodium has inherent oscillation cycles of protoplasmic streaming and thickness variation, how the plasmodium responds to various periods of external stretching stimuli can shed light on the other biological rhythm phenomena. The experimental results show that the plasmodium exhibits response to periodic mechanical stimulation and changes its locomotion speed depending on the period of the stretching stimuli. (paper)

Quantum mechanics

International Nuclear Information System (INIS)

Rae, A.I.M.

1981-01-01

This book, based on a thirty lecture course given to students at the beginning of their second year, covers the quantum mechanics required by physics undergraduates. Early chapters deal with wave mechanics, including a discussion of the energy states of the hydrogen atom. These are followed by a more formal development of the theory, leading to a discussion of some advanced applications and an introduction to the conceptual problems associated with quantum measurement theory. Emphasis is placed on the fundamentals of quantum mechanics. Problems are included at the end of each chapter. (U.K.)

Statistical mechanics

CERN Document Server

Schwabl, Franz

2006-01-01

The completely revised new edition of the classical book on Statistical Mechanics covers the basic concepts of equilibrium and non-equilibrium statistical physics. In addition to a deductive approach to equilibrium statistics and thermodynamics based on a single hypothesis - the form of the microcanonical density matrix - this book treats the most important elements of non-equilibrium phenomena. Intermediate calculations are presented in complete detail. Problems at the end of each chapter help students to consolidate their understanding of the material. Beyond the fundamentals, this text demonstrates the breadth of the field and its great variety of applications. Modern areas such as renormalization group theory, percolation, stochastic equations of motion and their applications to critical dynamics, kinetic theories, as well as fundamental considerations of irreversibility, are discussed. The text will be useful for advanced students of physics and other natural sciences; a basic knowledge of quantum mechan...

Fundamental Structure of Loop Quantum Gravity

Science.gov (United States)

Han, Muxin; Ma, Yongge; Huang, Weiming

In the recent twenty years, loop quantum gravity, a background independent approach to unify general relativity and quantum mechanics, has been widely investigated. The aim of loop quantum gravity is to construct a mathematically rigorous, background independent, non-perturbative quantum theory for a Lorentzian gravitational field on a four-dimensional manifold. In the approach, the principles of quantum mechanics are combined with those of general relativity naturally. Such a combination provides us a picture of, so-called, quantum Riemannian geometry, which is discrete on the fundamental scale. Imposing the quantum constraints in analogy from the classical ones, the quantum dynamics of gravity is being studied as one of the most important issues in loop quantum gravity. On the other hand, the semi-classical analysis is being carried out to test the classical limit of the quantum theory. In this review, the fundamental structure of loop quantum gravity is presented pedagogically. Our main aim is to help non-experts to understand the motivations, basic structures, as well as general results. It may also be beneficial to practitioners to gain insights from different perspectives on the theory. We will focus on the theoretical framework itself, rather than its applications, and do our best to write it in modern and precise langauge while keeping the presentation accessible for beginners. After reviewing the classical connection dynamical formalism of general relativity, as a foundation, the construction of the kinematical Ashtekar-Isham-Lewandowski representation is introduced in the content of quantum kinematics. The algebraic structure of quantum kinematics is also discussed. In the content of quantum dynamics, we mainly introduce the construction of a Hamiltonian constraint operator and the master constraint project. At last, some applications and recent advances are outlined. It should be noted that this strategy of quantizing gravity can also be extended to

Crowding in Visual Working Memory Reveals Its Spatial Resolution and the Nature of Its Representations.

Science.gov (United States)

Tamber-Rosenau, Benjamin J; Fintzi, Anat R; Marois, René

2015-09-01

Spatial resolution fundamentally limits any image representation. Although this limit has been extensively investigated for perceptual representations by assessing how neighboring flankers degrade the perception of a peripheral target with visual crowding, the corresponding limit for representations held in visual working memory (VWM) is unknown. In the present study, we evoked crowding in VWM and directly compared resolution in VWM and perception. Remarkably, the spatial resolution of VWM proved to be no worse than that of perception. However, mixture modeling of errors caused by crowding revealed the qualitatively distinct nature of these representations. Perceptual crowding errors arose from both increased imprecision in target representations and substitution of flankers for targets. By contrast, VWM crowding errors arose exclusively from substitutions, which suggests that VWM transforms analog perceptual representations into discrete items. Thus, although perception and VWM share a common resolution limit, exceeding this limit reveals distinct mechanisms for perceiving images and holding them in mind. © The Author(s) 2015.

Mastery of fundamental movement skills among children in New South Wales: prevalence and sociodemographic distribution.

Science.gov (United States)

Okely, A D; Booth, M L

2004-09-01

Fundamental movement skills form the foundation for many of the specific motor skills employed in popular sports and leisure activities. Little data exist on the prevalence and socioeconomic distribution of fundamental movement skill mastery among young children in Australia. This study process-assessed performance on six fundamental movement skills in a randomly selected sample of students from Years 1 through 3 in the Sydney metropolitan area of New South Wales. The prevalence and sociodemographic distribution of mastery and near mastery for each skill and each skill component is reported for boys and girls in each school year. The findings revealed that the prevalence of mastery and near mastery of each of fundamental movement skill was generally low. Boys performed significantly better than girls in the run and in the four object-control skills (throw, catch, kick, and strike) whilst girls performed better than boys in the skip. There was no consistent association between prevalence of skill mastery and socio-economic status (SES), with only the kick and vertical jump for boys and catch, dodge, and vertical jump for girls differing across SES tertiles. Based on these results, we recommend that adequate curriculum time, resources, and professional development continue to be devoted to fundamental movement skills in NSW primary schools.

Equilibrium statistical mechanics

CERN Document Server

Jackson, E Atlee

2000-01-01

Ideal as an elementary introduction to equilibrium statistical mechanics, this volume covers both classical and quantum methodology for open and closed systems. Introductory chapters familiarize readers with probability and microscopic models of systems, while additional chapters describe the general derivation of the fundamental statistical mechanics relationships. The final chapter contains 16 sections, each dealing with a different application, ordered according to complexity, from classical through degenerate quantum statistical mechanics. Key features include an elementary introduction t

Relations between nonlinear Riccati equations and other equations in fundamental physics

International Nuclear Information System (INIS)

Schuch, Dieter

2014-01-01

Many phenomena in the observable macroscopic world obey nonlinear evolution equations while the microscopic world is governed by quantum mechanics, a fundamental theory that is supposedly linear. In order to combine these two worlds in a common formalism, at least one of them must sacrifice one of its dogmas. Linearizing nonlinear dynamics would destroy the fundamental property of this theory, however, it can be shown that quantum mechanics can be reformulated in terms of nonlinear Riccati equations. In a first step, it will be shown that the information about the dynamics of quantum systems with analytical solutions can not only be obtainable from the time-dependent Schrödinger equation but equally-well from a complex Riccati equation. Comparison with supersymmetric quantum mechanics shows that even additional information can be obtained from the nonlinear formulation. Furthermore, the time-independent Schrödinger equation can also be rewritten as a complex Riccati equation for any potential. Extension of the Riccati formulation to include irreversible dissipative effects is straightforward. Via (real and complex) Riccati equations, other fields of physics can also be treated within the same formalism, e.g., statistical thermodynamics, nonlinear dynamical systems like those obeying a logistic equation as well as wave equations in classical optics, Bose- Einstein condensates and cosmological models. Finally, the link to abstract ''quantizations'' such as the Pythagorean triples and Riccati equations connected with trigonometric and hyperbolic functions will be shown

Meta-analysis reveals host-dependent nitrogen recycling as a mechanism of symbiont control in Aiptasia

KAUST Repository

Cui, Guoxin

2018-02-22

The metabolic symbiosis with photosynthetic algae of the genus Symbiodinium allows corals to thrive in the oligotrophic environments of tropical seas. Many aspects of this relationship have been investigated using transcriptomic analyses in the emerging model organism Aiptasia. However, previous studies identified thousands of putatively symbiosis-related genes, making it difficult to disentangle symbiosis-induced responses from undesired experimental parameters. Using a meta-analysis approach, we identified a core set of 731 high-confidence symbiosis-associated genes that reveal host-dependent recycling of waste ammonium and amino acid synthesis as central processes in this relationship. Combining transcriptomic and metabolomic analyses, we show that symbiont-derived carbon enables host recycling of ammonium into nonessential amino acids. We propose that this provides a regulatory mechanism to control symbiont growth through a carbon-dependent negative feedback of nitrogen availability to the symbiont. The dependence of this mechanism on symbiont-derived carbon highlights the susceptibility of this symbiosis to changes in carbon translocation, as imposed by environmental stress.

Comparative genomic analysis of isoproturon-mineralizing sphingomonads reveals the isoproturon catabolic mechanism.

Science.gov (United States)

Yan, Xin; Gu, Tao; Yi, Zhongquan; Huang, Junwei; Liu, Xiaowei; Zhang, Ji; Xu, Xihui; Xin, Zhihong; Hong, Qing; He, Jian; Spain, Jim C; Li, Shunpeng; Jiang, Jiandong

2016-12-01

The worldwide use of the phenylurea herbicide, isoproturon (IPU), has resulted in considerable concern about its environmental fate. Although many microbial metabolites of IPU are known and IPU-mineralizing bacteria have been isolated, the molecular mechanism of IPU catabolism has not been elucidated yet. In this study, complete genes that encode the conserved IPU catabolic pathway were revealed, based on comparative analysis of the genomes of three IPU-mineralizing sphingomonads and subsequent experimental validation. The complete genes included a novel hydrolase gene ddhA, which is responsible for the cleavage of the urea side chain of the IPU demethylated products; a distinct aniline dioxygenase gene cluster adoQTA1A2BR, which has a broad substrate range; and an inducible catechol meta-cleavage pathway gene cluster adoXEGKLIJC. Furthermore, the initial mono-N-demethylation genes pdmAB were further confirmed to be involved in the successive N-demethylation of the IPU mono-N-demethylated product. These IPU-catabolic genes were organized into four transcription units and distributed on three plasmids. They were flanked by multiple mobile genetic elements and highly conserved among IPU-mineralizing sphingomonads. The elucidation of the molecular mechanism of IPU catabolism will enhance our understanding of the microbial mineralization of IPU and provide insights into the evolutionary scenario of the conserved IPU-catabolic pathway. © 2016 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

Fundamentals of nuclear science and engineering

CERN Document Server

Shultis, J Kenneth

2007-01-01

FUNDAMENTAL CONCEPTS Modern Units The Atom Chart of Nuclides MODERN PHYSICS CONCEPTS The Special Theory of Relativity Radiation as Waves and Particles Quantum Mechanics Derivation of Some Special Relativity Results Solutions to Schrodinger's Wave Equation ATOMIC/NUCLEAR MODELS Development of the Modern Atom Model Models of the Nucleus NUCLEAR ENERGETICS Binding Energy Nucleon Separation Energy Nuclear Reactions Examples of Binary Nuclear Reactions Q-Value for a Reaction Conservation of Charge and the Calculation of Q-values Q-Value for reactions Producing Excited Nuclei RADIOACTIVITY Overview Types of Radioactive Decay Radioactive Decay Diagrams Energetics of Radioactive Decay Characteristics of Radioactive Decay Decay Dynamics Naturally Occurring Radionuclides Radiodating Radioactive Decay Data BINARY NUCLEAR REACTIONS Types of Binary Reactions Kinematics of Binary Two-Product Nuclear Reactions Reaction Threshold Energy Applications of Binary Kinematics Reactions...

Land Prices and Fundamentals

OpenAIRE

Koji Nakamura; Yumi Saita

2007-01-01

This paper examines the long-term relationship between macro economic fundamentals and the weighted-average land price indicators, which are supposed to be more appropriate than the official land price indicators when analyzing their impacts on the macro economy. In many cases, we find the cointegrating relationships between the weighted-average land price indicators and the discounted present value of land calculated based on the macro economic fundamentals indicators. We also find that the ...

Plasma Astrophysics, Part I Fundamentals and Practice

CERN Document Server

Somov, Boris V

2006-01-01

This well-illustrated monograph is devoted to classic fundamentals, current practice, and perspectives of modern plasma astrophysics. The first part is unique in covering all the basic principles and practical tools required for understanding and working in plasma astrophysics. The second part presents the physics of magnetic reconnection and flares of electromagnetic origin in space plasmas within the solar system; single and double stars, relativistic objects, accretion disks, and their coronae are also covered. This book is designed mainly for professional researchers in astrophysics. However, it will also be interesting and useful to graduate students in space sciences, geophysics, as well as advanced students in applied physics and mathematics seeking a unified view of plasma physics and fluid mechanics.

Fundamental volatility is regime specific

NARCIS (Netherlands)

Arnold, I.J.M.; MacDonald, R.; Vries, de C.G.

2006-01-01

A widely held notion holds that freely floating exchange rates are excessively volatile when judged against fundamentals and when moving from fixed to floating exchange rates. We re-examine the data and conclude that the disparity between the fundamentals and exchange rate volatility is more

Electrophysiological potentials reveal cortical mechanisms for mental imagery, mental simulation, and grounded (embodied cognition

Directory of Open Access Journals (Sweden)

Haline E. Schendan

2012-09-01

Full Text Available Grounded cognition theory proposes that cognition, including meaning, is grounded in sensorimotor processing. The mechanism for grounding cognition is mental simulation, which is a type of mental imagery that re-enacts modal processing. To reveal top-down, cortical mechanisms for mental simulation of shape, event-related potentials were recorded to face and object pictures preceded by mental imagery of a picture. Mental imagery of the identical face or object (congruous condition facilitated not only categorical perception (VPP/N170 but also later visual knowledge (N3[00] complex and linguistic knowledge (N400 for faces more than objects, and strategic semantic analysis (late positive complex between 200 and 700 ms. The later effects resembled semantic congruity effects with pictures. Mental imagery also facilitated category decisions, as a P3(00 peaked earlier for congruous than incongruous (other category pictures, resembling the case when identical pictures repeat immediately. Thus mental imagery mimics semantic congruity and immediate repetition priming processes with pictures. Perception control results showed the opposite for faces and were in the same direction for objects: Perceptual repetition adapts (and so impairs processing of perceived faces from categorical perception onwards, but primes processing of objects during categorical perception, visual knowledge processes, and strategic semantic analysis. For both imagery and perception, differences between faces and objects support domain-specificity and indicate that cognition is grounded in modal processing. Altogether, this direct neural evidence reveals that top-down processes of mental imagery sustain an imagistic representation that mimics perception well enough to prime subsequent perception and cognition. This also suggests that automatic mental simulation of the visual shape of faces and objects operates between 200 and 400 ms, and strategic mental simulation operates between

[From fundamental research to clinical development: a review of orthodontics].

Science.gov (United States)

Zhao, Zhi-he; Bai, Ding

2011-11-01

In recent years, new approaches to the diagnosis and treatment of malocclusion have emerged. The diagnostic and therapeutic techniques of orthodontics have evolved from two dimensions to five dimensions with the development of computer technology, auto-machining and imaging. Furthermore, interdisciplinary study has become the driving force for the advancement of fundamental research in orthodontics. The mechanisms of malocclusion and orthodontic tooth movement have been extensively studied to the details at the level of cells and molecules.

Bayesian analysis of rotating machines - A statistical approach to estimate and track the fundamental frequency

DEFF Research Database (Denmark)

Pedersen, Thorkild Find

2003-01-01

frequency and the related frequencies as orders of the fundamental frequency. When analyzing rotating or reciprocating machines it is important to know the running speed. Usually this requires direct access to the rotating parts in order to mount a dedicated tachometer probe. In this thesis different......Rotating and reciprocating mechanical machines emit acoustic noise and vibrations when they operate. Typically, the noise and vibrations are concentrated in narrow frequency bands related to the running speed of the machine. The frequency of the running speed is referred to as the fundamental...

Transcriptome profiling of a curdlan-producing Agrobacterium reveals conserved regulatory mechanisms of exopolysaccharide biosynthesis

Directory of Open Access Journals (Sweden)

Ruffing Anne M

2012-02-01

Full Text Available Abstract Background The ability to synthesize exopolysaccharides (EPS is widespread among microorganisms, and microbial EPS play important roles in biofilm formation, pathogen persistence, and applications in the food and medical industries. Although it is well established that EPS synthesis is invariably in response to environmental cues, it remains largely unknown how various environmental signals trigger activation of the biochemical synthesis machinery. Results We report here the transcriptome profiling of Agrobacterium sp. ATCC 31749, a microorganism that produces large amounts of a glucose polymer known as curdlan under nitrogen starvation. Transcriptome analysis revealed a nearly 100-fold upregulation of the curdlan synthesis operon upon transition to nitrogen starvation, thus establishing the prominent role that transcriptional regulation plays in the EPS synthesis. In addition to known mechanisms of EPS regulation such as activation by c-di-GMP, we identify novel mechanisms of regulation in ATCC 31749, including RpoN-independent NtrC regulation and intracellular pH regulation by acidocalcisomes. Furthermore, we show evidence that curdlan synthesis is also regulated by conserved cell stress responses, including polyphosphate accumulation and the stringent response. In fact, the stringent response signal, pppGpp, appears to be indispensible for transcriptional activation of curdlan biosynthesis. Conclusions This study identifies several mechanisms regulating the synthesis of curdlan, an EPS with numerous applications. These mechanisms are potential metabolic engineering targets for improving the industrial production of curdlan from Agrobacterium sp. ATCC 31749. Furthermore, many of the genes identified in this study are highly conserved across microbial genomes, and we propose that the molecular elements identified in this study may serve as universal regulators of microbial EPS synthesis.

A new approach to teaching the foundamentals of the relativity mechanics

International Nuclear Information System (INIS)

Tyapkin, A.A.

1985-01-01

A new approach to teaching the fundamentals of relativistic mechanics is discussed. The aim is to achieve deeper understanding of the special theory of relativity. The methodic innovation is that the Galilean coordinates are used to describe rates of the physical processes represented under equivalent physical conditions in inertial systems which move regarding one another. Such consideration reveals general features in deviations of physical laws from the invariance in respect of the Galilean transformations. Those deviations manifest themselves in general relative changes of the rates of all physical processes, occuring with preservation of kinematic likelihood. Those changes of rates of processes in the direction of relative movement of a reference system are related to the difference of eigensimultaneities in different inertial systems of reference, as established in the relativity theory. This interpretation of the relativity theory is shown to be related to ideas of Poincare and Lorentz who developed the fundamentals of the relativity theory

Fundamental course of measuring. Pt. 2. 4. enlarged ed.

International Nuclear Information System (INIS)

Merz, L.

1975-01-01

The fundamental course of the electrical measuring of non-electrical parameters aims to fulfill the task of presenting the present knowledge on the basic measuring methods in simple language and illustrative form. The present part II deals especially with measuring methods in heat and process engineering in the industrial field. Following the introduction in part A, the techniques of electrical probes are mainly described, and it is shown which mechanical probes cannot yet be replaced by electrical ones. Part C describes the techniques of measuring transducers. (ORU) [de

Integrative Genomics Reveals Mechanisms of Copy Number Alterations Responsible for Transcriptional Deregulation in Colorectal Cancer

Science.gov (United States)

Camps, Jordi; Nguyen, Quang Tri; Padilla-Nash, Hesed M.; Knutsen, Turid; McNeil, Nicole E.; Wangsa, Danny; Hummon, Amanda B.; Grade, Marian; Ried, Thomas; Difilippantonio, Michael J.

2016-01-01

To evaluate the mechanisms and consequences of chromosomal aberrations in colorectal cancer (CRC), we used a combination of spectral karyotyping, array comparative genomic hybridization (aCGH), and array-based global gene expression profiling on 31 primary carcinomas and 15 established cell lines. Importantly, aCGH showed that the genomic profiles of primary tumors are recapitulated in the cell lines. We revealed a preponderance of chromosome breakpoints at sites of copy number variants (CNVs) in the CRC cell lines, a novel mechanism of DNA breakage in cancer. The integration of gene expression and aCGH led to the identification of 157 genes localized within high-level copy number changes whose transcriptional deregulation was significantly affected across all of the samples, thereby suggesting that these genes play a functional role in CRC. Genomic amplification at 8q24 was the most recurrent event and led to the overexpression of MYC and FAM84B. Copy number dependent gene expression resulted in deregulation of known cancer genes such as APC, FGFR2, and ERBB2. The identification of only 36 genes whose localization near a breakpoint could account for their observed deregulated expression demonstrates that the major mechanism for transcriptional deregulation in CRC is genomic copy number changes resulting from chromosomal aberrations. PMID:19691111

Nanostructured metals. Fundamentals to applications

International Nuclear Information System (INIS)

Grivel, J.-C.; Hansen, N.; Huang, X.; Juul Jensen, D.; Mishin, O.V.; Nielsen, S.F.; Pantleon, W.; Toftegaard, H.; Winther, G.; Yu, T.

2009-01-01

In the today's world, materials science and engineering must as other technical fields focus on sustainability. Raw materials and energy have to be conserved and metals with improved or new structural and functional properties must be invented, developed and brought to application. In this endeavour a very promising route is to reduce the structural scale of metallic materials, thereby bridging industrial metals of today with emerging nanometals of tomorrow, i.e. structural scales ranging from a few micrometres to the nanometre regime. While taking a focus on metals with structures in this scale regime the symposium spans from fundamental aspects towards applications, uniting materials scientists and technologists. A holistic approach characterizes the themes of the symposium encompassing synthesis, characterization, modelling and performance where in each area significant progress has been made in recent years. Synthesis now covers top-down processes, e.g. plastic deformation, and bottom-up processes, e.g. chemical and physical synthesis. In the area of structural and mechanical characterization advanced techniques are now widely applied and in-situ techniques for structural characterization under mechanical or thermal loading are under rapid development in both 2D and 3D. Progress in characterization techniques has led to a precise description of different boundaries (grain, dislocation, twin, phase), and of how they form and evolve, also including theoretical modelling and simulations of structures, properties and performance. (au)

Novel Evasion Mechanisms of the Classical Complement Pathway.

Science.gov (United States)

Garcia, Brandon L; Zwarthoff, Seline A; Rooijakkers, Suzan H M; Geisbrecht, Brian V

2016-09-15

Complement is a network of soluble and cell surface-associated proteins that gives rise to a self-amplifying, yet tightly regulated system with fundamental roles in immune surveillance and clearance. Complement becomes activated on the surface of nonself cells by one of three initiating mechanisms known as the classical, lectin, and alternative pathways. Evasion of complement function is a hallmark of invasive pathogens and hematophagous organisms. Although many complement-inhibition strategies hinge on hijacking activities of endogenous complement regulatory proteins, an increasing number of uniquely evolved evasion molecules have been discovered over the past decade. In this review, we focus on several recent investigations that revealed mechanistically distinct inhibitors of the classical pathway. Because the classical pathway is an important and specific mediator of various autoimmune and inflammatory disorders, in-depth knowledge of novel evasion mechanisms could direct future development of therapeutic anti-inflammatory molecules. Copyright © 2016 by The American Association of Immunologists, Inc.

Fundamentals of Protein NMR Spectroscopy

CERN Document Server

Rule, Gordon S

2006-01-01

NMR spectroscopy has proven to be a powerful technique to study the structure and dynamics of biological macromolecules. Fundamentals of Protein NMR Spectroscopy is a comprehensive textbook that guides the reader from a basic understanding of the phenomenological properties of magnetic resonance to the application and interpretation of modern multi-dimensional NMR experiments on 15N/13C-labeled proteins. Beginning with elementary quantum mechanics, a set of practical rules is presented and used to describe many commonly employed multi-dimensional, multi-nuclear NMR pulse sequences. A modular analysis of NMR pulse sequence building blocks also provides a basis for understanding and developing novel pulse programs. This text not only covers topics from chemical shift assignment to protein structure refinement, as well as the analysis of protein dynamics and chemical kinetics, but also provides a practical guide to many aspects of modern spectrometer hardware, sample preparation, experimental set-up, and data pr...

Fundamental number theory with applications

CERN Document Server

Mollin, Richard A

2008-01-01

An update of the most accessible introductory number theory text available, Fundamental Number Theory with Applications, Second Edition presents a mathematically rigorous yet easy-to-follow treatment of the fundamentals and applications of the subject. The substantial amount of reorganizing makes this edition clearer and more elementary in its coverage. New to the Second Edition           Removal of all advanced material to be even more accessible in scope           New fundamental material, including partition theory, generating functions, and combinatorial number theory           Expa

Physical, experimental and numerical study of fundamental mechanisms involved in two-phase flows

International Nuclear Information System (INIS)

Mathieu, Benoit

2003-01-01

In this work, small-scale phenomena in two-phase flows with phase change are studied. First, some fundamental phenomena related to the heat and mass transfer at small scale are recalled. A physical model is then built in order to describe moving contact lines with phase change. In the second part, a numerical simulation method is built, that is able to describe the growth of a single bubble on a heated wall. Compared to existing methods, major improvements are obtained with respect to the conservation of the mass, the spurious currents related to interfacial forces and the physical description of the contact lines. Finally, an experimental investigation of the singular heat and mass transfer at the contact line is carried out. Preliminary results obtained on a simplified configuration are presented. (author) [fr

Optical anisotropy induced by mechanical strain around the fundamental gap of GaAs

Energy Technology Data Exchange (ETDEWEB)

Ortega-Gallegos, J.; Lastras-Martinez, A.; Lastras-Martinez, L.F. [Instituto de Investigacion en Comunicacion Optica, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, San Luis Potosi (Mexico); Balderas-Navarro, R.E. [Instituto de Investigacion en Comunicacion Optica, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, San Luis Potosi (Mexico); Facultad de Ciencias, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, San Luis Potosi (Mexico)

2008-07-01

We report on a theoretical-experimental study of reflectance anisotropy spectroscopy (RAS) of GaAs (001) crystals under uniaxial stress. The study was carried out in the energy region around the fundamental transition. RAS spectra in the energy range from 1.2-1.7 eV were measured with a photoelastic-modulator-based spectrometer. To induce an optical anisotropy, the GaAs crystals were thinned down to 400 {mu}m and an calibrated uniaxial stress was applied by deflection. RAS showed a line shape consisting of an oscillation at around E{sub 0}. On the basis of a perturbative approach employing the Pikus-Bir Hamiltonian, we calculated the RAS line shape and found a close agreement with the experimental spectra. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Mechanical influences on morphogenesis of the knee joint revealed through morphological, molecular and computational analysis of immobilised embryos.

Directory of Open Access Journals (Sweden)

Karen A Roddy

2011-02-01

Full Text Available Very little is known about the regulation of morphogenesis in synovial joints. Mechanical forces generated from muscle contractions are required for normal development of several aspects of normal skeletogenesis. Here we show that biophysical stimuli generated by muscle contractions impact multiple events during chick knee joint morphogenesis influencing differential growth of the skeletal rudiment epiphyses and patterning of the emerging tissues in the joint interzone. Immobilisation of chick embryos was achieved through treatment with the neuromuscular blocking agent Decamethonium Bromide. The effects on development of the knee joint were examined using a combination of computational modelling to predict alterations in biophysical stimuli, detailed morphometric analysis of 3D digital representations, cell proliferation assays and in situ hybridisation to examine the expression of a selected panel of genes known to regulate joint development. This work revealed the precise changes to shape, particularly in the distal femur, that occur in an altered mechanical environment, corresponding to predicted changes in the spatial and dynamic patterns of mechanical stimuli and region specific changes in cell proliferation rates. In addition, we show altered patterning of the emerging tissues of the joint interzone with the loss of clearly defined and organised cell territories revealed by loss of characteristic interzone gene expression and abnormal expression of cartilage markers. This work shows that local dynamic patterns of biophysical stimuli generated from muscle contractions in the embryo act as a source of positional information guiding patterning and morphogenesis of the developing knee joint.

Mechanical Influences on Morphogenesis of the Knee Joint Revealed through Morphological, Molecular and Computational Analysis of Immobilised Embryos

Science.gov (United States)

Roddy, Karen A.; Prendergast, Patrick J.; Murphy, Paula

2011-01-01

Very little is known about the regulation of morphogenesis in synovial joints. Mechanical forces generated from muscle contractions are required for normal development of several aspects of normal skeletogenesis. Here we show that biophysical stimuli generated by muscle contractions impact multiple events during chick knee joint morphogenesis influencing differential growth of the skeletal rudiment epiphyses and patterning of the emerging tissues in the joint interzone. Immobilisation of chick embryos was achieved through treatment with the neuromuscular blocking agent Decamethonium Bromide. The effects on development of the knee joint were examined using a combination of computational modelling to predict alterations in biophysical stimuli, detailed morphometric analysis of 3D digital representations, cell proliferation assays and in situ hybridisation to examine the expression of a selected panel of genes known to regulate joint development. This work revealed the precise changes to shape, particularly in the distal femur, that occur in an altered mechanical environment, corresponding to predicted changes in the spatial and dynamic patterns of mechanical stimuli and region specific changes in cell proliferation rates. In addition, we show altered patterning of the emerging tissues of the joint interzone with the loss of clearly defined and organised cell territories revealed by loss of characteristic interzone gene expression and abnormal expression of cartilage markers. This work shows that local dynamic patterns of biophysical stimuli generated from muscle contractions in the embryo act as a source of positional information guiding patterning and morphogenesis of the developing knee joint. PMID:21386908

Revealing Atomic-Level Mechanisms of Protein Allostery with Molecular Dynamics Simulations.

Directory of Open Access Journals (Sweden)

Samuel Hertig

2016-06-01

Full Text Available Molecular dynamics (MD simulations have become a powerful and popular method for the study of protein allostery, the widespread phenomenon in which a stimulus at one site on a protein influences the properties of another site on the protein. By capturing the motions of a protein's constituent atoms, simulations can enable the discovery of allosteric binding sites and the determination of the mechanistic basis for allostery. These results can provide a foundation for applications including rational drug design and protein engineering. Here, we provide an introduction to the investigation of protein allostery using molecular dynamics simulation. We emphasize the importance of designing simulations that include appropriate perturbations to the molecular system, such as the addition or removal of ligands or the application of mechanical force. We also demonstrate how the bidirectional nature of allostery-the fact that the two sites involved influence one another in a symmetrical manner-can facilitate such investigations. Through a series of case studies, we illustrate how these concepts have been used to reveal the structural basis for allostery in several proteins and protein complexes of biological and pharmaceutical interest.

Fundamentals of structural dynamics

CERN Document Server

Craig, Roy R

2006-01-01

From theory and fundamentals to the latest advances in computational and experimental modal analysis, this is the definitive, updated reference on structural dynamics.This edition updates Professor Craig's classic introduction to structural dynamics, which has been an invaluable resource for practicing engineers and a textbook for undergraduate and graduate courses in vibrations and/or structural dynamics. Along with comprehensive coverage of structural dynamics fundamentals, finite-element-based computational methods, and dynamic testing methods, this Second Edition includes new and e

Evolution of the Digital Society Reveals Balance between Viral and Mass Media Influence

Science.gov (United States)

Kleineberg, Kaj-Kolja; Boguñá, Marián

2014-07-01

Online social networks (OSNs) enable researchers to study the social universe at a previously unattainable scale. The worldwide impact and the necessity to sustain the rapid growth of OSNs emphasize the importance of unraveling the laws governing their evolution. Empirical results show that, unlike many real-world growing networked systems, OSNs follow an intricate path that includes a dynamical percolation transition. In light of these results, we present a quantitative two-parameter model that reproduces the entire topological evolution of a quasi-isolated OSN with unprecedented precision from the birth of the network. This allows us to precisely gauge the fundamental macroscopic and microscopic mechanisms involved. Our findings suggest that the coupling between the real preexisting underlying social structure, a viral spreading mechanism, and mass media influence govern the evolution of OSNs. The empirical validation of our model, on a macroscopic scale, reveals that virality is 4-5 times stronger than mass media influence and, on a microscopic scale, individuals have a higher subscription probability if invited by weaker social contacts, in agreement with the "strength of weak ties" paradigm.

MDL, Collineations and the Fundamental Matrix

OpenAIRE

Maybank , Steve; Sturm , Peter

1999-01-01

International audience; Scene geometry can be inferred from point correspondences between two images. The inference process includes the selection of a model. Four models are considered: background (or null), collineation, affine fundamental matrix and fundamental matrix. It is shown how Minimum Description Length (MDL) can be used to compare the different models. The main result is that there is little reason for preferring the fundamental matrix model over the collineation model, even when ...

Revealing the reaction mechanisms of Li–O2 batteries using environmental transmission electron microscopy

Energy Technology Data Exchange (ETDEWEB)

Luo, Langli; Liu, Bin; Song, Shidong; Xu, Wu; Zhang, Ji-Guang; Wang, Chongmin

2017-03-27

The capacity, Coulombic efficiency, rate, and cyclability of a Li-O2 battery critically depend on the electrode reaction mechanism and the structure/morphology of the reaction product as well as their spatial and temporal evolution1-8, which are all further complicated by the choice of different electrolyte. For the case of aprotic cell, the discharge product, Li2O2, is formed through solution and surface mechanisms9,10, but little is known on the formation mechanism of the perplexing morphology of the reaction product11-15. For the case of Li-O2 battery using solid electrolyte, neither electrode reaction mechanism nor the nature of the reaction production is known. Herein, we reveal the full cycle reaction pathway for Li-O2 batteries and its correlation with the nature of the reaction product. Using an aberration-corrected environmental TEM under oxygen environment, we captured, for the first time, the morphology and phase evolution on the carbon nanotube (CNT) cathode of a working solid-state Li-O2 nano-battery16 and directly correlated these features with electrochemical reaction. We found that the oxygen reduction reaction on CNTs initially produces LiO2, which subsequently evolves to Li2O2 and O2 through disproportionation reaction. Surprisingly it is just the releasing of O2 that inflates the particles to a hollow structure with a Li2O outer surface layer and Li2O2 inner-shell, demonstrating that, in general, accommodation of the released O2 coupled with the Li+ ion diffusion and electron transport paths across both spatial and temporal scales critically governs the morphology of the discharging/charging product in Li-O2 system. We anticipate that the direct observation of Li-O2 reaction mechanisms and their correlation with the morphology of the reaction product set foundation for quantitative understanding/modeling of the electrochemical processes in the Li-O2 system, enabling rational design of both solid-state and aprotic Li-O2 batteries.

Comparative proteomics and codon substitution analysis reveal mechanisms of differential resistance to hypoxia in congeneric snails

KAUST Repository

Mu, Huawei; Sun, Jin; Cheung, Siu Gin; Fang, Ling; Zhou, Haiyun; Luan, Tiangang; Zhang, Huoming; Wong, Chris K.C.; Qiu, Jian-Wen

2017-01-01

Although high-throughput proteomics has been widely applied to study mechanisms of environmental adaptation, the conclusions from studies that are based on one species can be confounded by phylogeny. We compare the freshwater snail Pomacea canaliculata (a notorious invasive species) and its congener Pomacea diffusa (a non-invasive species) to understand the molecular mechanisms of their differential resistance to hypoxia. A 72-h acute exposure experiment showed that P. canaliculata is more tolerant to hypoxia than P. diffusa. The two species were then exposed to three levels of dissolved oxygen (6.7, 2.0 and 1.0mgL−1) for 8h, and their gill proteins were analyzed using iTRAQ-coupled LC-MS/MS. The two species showed striking differences in protein expression profiles, with the more hypoxia tolerant P. canaliculata having more up-regulated proteins in signal transduction and down-regulated proteins in glycolysis and the tricarboxylic acid cycle. Evolutionary analysis revealed five orthologous genes encoding differentially expressed proteins having clear signal of positive selection, indicating selection has acted on some of the hypoxia responsive genes. Our case study has highlighted the potential of integrated proteomics and comparative evolutionary analysis for understanding the genetic basis of adaptation to global environmental change in non-model species. SignificanceRapid globalization in recent decades has greatly facilitated species introduction around the world. Successfully established introduced species, so-called invasive species, have threatened the invaded ecosystems. There has been substantial interest in studying how invasive species respond to extreme environmental conditions because the results can help not only predict their range of expansion and manage their impact, but also may reveal the adaptive mechanisms underlying their invasiveness. Our study has adopted a comparative approach to study the differential physiological and proteomic

Comparative proteomics and codon substitution analysis reveal mechanisms of differential resistance to hypoxia in congeneric snails

KAUST Repository

Mu, Huawei

2017-11-06

Although high-throughput proteomics has been widely applied to study mechanisms of environmental adaptation, the conclusions from studies that are based on one species can be confounded by phylogeny. We compare the freshwater snail Pomacea canaliculata (a notorious invasive species) and its congener Pomacea diffusa (a non-invasive species) to understand the molecular mechanisms of their differential resistance to hypoxia. A 72-h acute exposure experiment showed that P. canaliculata is more tolerant to hypoxia than P. diffusa. The two species were then exposed to three levels of dissolved oxygen (6.7, 2.0 and 1.0mgL−1) for 8h, and their gill proteins were analyzed using iTRAQ-coupled LC-MS/MS. The two species showed striking differences in protein expression profiles, with the more hypoxia tolerant P. canaliculata having more up-regulated proteins in signal transduction and down-regulated proteins in glycolysis and the tricarboxylic acid cycle. Evolutionary analysis revealed five orthologous genes encoding differentially expressed proteins having clear signal of positive selection, indicating selection has acted on some of the hypoxia responsive genes. Our case study has highlighted the potential of integrated proteomics and comparative evolutionary analysis for understanding the genetic basis of adaptation to global environmental change in non-model species. SignificanceRapid globalization in recent decades has greatly facilitated species introduction around the world. Successfully established introduced species, so-called invasive species, have threatened the invaded ecosystems. There has been substantial interest in studying how invasive species respond to extreme environmental conditions because the results can help not only predict their range of expansion and manage their impact, but also may reveal the adaptive mechanisms underlying their invasiveness. Our study has adopted a comparative approach to study the differential physiological and proteomic

Virtual and composite fundamentals in the ERM

NARCIS (Netherlands)

Knot, KHW; Sturm, JE

1999-01-01

A latent-variable approach is applied to identify the appropriate driving process for fundamental exchange rates in the ERM. From the time-series characteristics of so-called "virtual fundamentals" and "composite fundamentals", a significant degree of mean reversion can be asserted. The relative

Fundamentals of Geophysics

Science.gov (United States)

Frohlich, Cliff

Choosing an intermediate-level geophysics text is always problematic: What should we teach students after they have had introductory courses in geology, math, and physics, but little else? Fundamentals of Geophysics is aimed specifically at these intermediate-level students, and the author's stated approach is to construct a text “using abundant diagrams, a simplified mathematical treatment, and equations in which the student can follow each derivation step-by-step.” Moreover, for Lowrie, the Earth is round, not flat—the “fundamentals of geophysics” here are the essential properties of our Earth the planet, rather than useful techniques for finding oil and minerals. Thus this book is comparable in both level and approach to C. M. R. Fowler's The Solid Earth (Cambridge University Press, 1990).

Fundamental Power Couplers for Superconducting Cavities

International Nuclear Information System (INIS)

Isidoro E. Campisi

2001-01-01

Fundamental power couplers (FPC's) for superconducting cavities must meet very strict requirements to perform at high power levels (hundreds of kilowatts) and in a variety of conditions (CS, pulsed, travelling wave, standing wave) without adversely affecting the performance of the cavities they are powering. Producing good coupler designs and achieving operational performances in accelerator environments are challenging tasks that have traditionally involved large resources from many laboratories. The designs involve state-of-the-art activities in RF, cryogenic and mechanical engineering, materials science, vacuum technology, and electromagnetic field modeling. Handling, assembly and conditioning procedures have been developed to achieve ever-increasing power levels and more reliable operation. In this paper, the technical issues associated with the design, construction, assembly, processing, and operation of FPC's will be reviewed, together with the progress in FPC activities in several laboratories during the past few years

Fundamentals of machine elements SI version

CERN Document Server

Schmid, Steven R; Jacobson, Bo O

2014-01-01

Part I - FundamentalsIntroductionWhat is Design?Design of Mechanical SystemsDesign as a Multidisciplinary EndeavorDesign of Machine ElementsComputers in DesignCatalogs and VendorsUnitsUnit ChecksSignificant FiguresSummaryLoad, Stress, and StrainIntroductionCritical SectionLoad Classification and Sign ConventionSupport ReactionsStatic EquilibriumFree-Body DiagramSupported BeamsShear and Moment DiagramsStressStress ElementStress TensorPlane StressMohr's CircleThree-Dimensional StressesOctahedral StressesStrainStrain TensorPlane StrainSummaryIntroduction to Materials and ManufacturingIntroductionDuctile and Brittle MaterialsClassification of Solid MaterialsStress-Strain DiagramsProperties of Solid MaterialsStress-Strain RelationshipsTwo-Parameter Materials ChartsEffects of ManufacturingSummaryStresses and StrainsIntroductionProperties of Beam Cross SectionsNormal Stress and StrainTorsionBending Stress and StrainTransverse Shear Stress and StrainSummaryDeformationIntroductionMoment-Curvature RelationSingularity F...

Automatic generation of predictive dynamic models reveals nuclear phosphorylation as the key Msn2 control mechanism.

Science.gov (United States)

Sunnåker, Mikael; Zamora-Sillero, Elias; Dechant, Reinhard; Ludwig, Christina; Busetto, Alberto Giovanni; Wagner, Andreas; Stelling, Joerg

2013-05-28

Predictive dynamical models are critical for the analysis of complex biological systems. However, methods to systematically develop and discriminate among systems biology models are still lacking. We describe a computational method that incorporates all hypothetical mechanisms about the architecture of a biological system into a single model and automatically generates a set of simpler models compatible with observational data. As a proof of principle, we analyzed the dynamic control of the transcription factor Msn2 in Saccharomyces cerevisiae, specifically the short-term mechanisms mediating the cells' recovery after release from starvation stress. Our method determined that 12 of 192 possible models were compatible with available Msn2 localization data. Iterations between model predictions and rationally designed phosphoproteomics and imaging experiments identified a single-circuit topology with a relative probability of 99% among the 192 models. Model analysis revealed that the coupling of dynamic phenomena in Msn2 phosphorylation and transport could lead to efficient stress response signaling by establishing a rate-of-change sensor. Similar principles could apply to mammalian stress response pathways. Systematic construction of dynamic models may yield detailed insight into nonobvious molecular mechanisms.

Monitoring of Structures and Mechanical Systems Using Virtual Visual Sensors for Video Analysis: Fundamental Concept and Proof of Feasibility

Directory of Open Access Journals (Sweden)

Thomas Schumacher

2013-12-01

Full Text Available Structural health monitoring (SHM has become a viable tool to provide owners of structures and mechanical systems with quantitative and objective data for maintenance and repair. Traditionally, discrete contact sensors such as strain gages or accelerometers have been used for SHM. However, distributed remote sensors could be advantageous since they don’t require cabling and can cover an area rather than a limited number of discrete points. Along this line we propose a novel monitoring methodology based on video analysis. By employing commercially available digital cameras combined with efficient signal processing methods we can measure and compute the fundamental frequency of vibration of structural systems. The basic concept is that small changes in the intensity value of a monitored pixel with fixed coordinates caused by the vibration of structures can be captured by employing techniques such as the Fast Fourier Transform (FFT. In this paper we introduce the basic concept and mathematical theory of this proposed so-called virtual visual sensor (VVS, we present a set of initial laboratory experiments to demonstrate the accuracy of this approach, and provide a practical in-service monitoring example of an in-service bridge. Finally, we discuss further work to improve the current methodology.

Cryogenic EBSD reveals structure of directionally solidified ice–polymer composite

Energy Technology Data Exchange (ETDEWEB)

Donius, Amalie E., E-mail: amalie.donius@gmail.com [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Obbard, Rachel W., E-mail: Rachel.W.Obbard@dartmouth.edu [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Burger, Joan N., E-mail: ridge.of.the.ancients@gmail.com [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Hunger, Philipp M., E-mail: philipp.m.hunger@gmail.com [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Baker, Ian, E-mail: Ian.Baker@dartmouth.edu [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Doherty, Roger D., E-mail: dohertrd@drexel.edu [Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Wegst, Ulrike G.K., E-mail: ulrike.wegst@dartmouth.edu [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States)

2014-07-01

Despite considerable research efforts on directionally solidified or freeze-cast materials in recent years, little fundamental knowledge has been gained that links model with experiment. In this contribution, the cryogenic characterization of directionally solidified polymer solutions illustrates, how powerful cryo-scanning electron microscopy combined with electron backscatter diffraction is for the structural characterization of ice–polymer composite materials. Under controlled sublimation, the freeze-cast polymer scaffold structure is revealed and imaged with secondary electrons. Electron backscatter diffraction fabric analysis shows that the ice crystals, which template the polymer scaffold and create the lamellar structure, have a-axes oriented parallel to the direction of solidification and the c-axes perpendicular to it. These results indicate the great potential of both cryo-scanning electron microscopy and cryo-electron backscatter diffraction in gaining fundamental knowledge of structure–property–processing correlations. - Highlights: • Cryo-SEM of freeze-cast polymer solution reveals an ice-templated structure. • Cryo-EBSD reveals the ice crystal a-axis to parallel the solidification direction. • The honeycomb-like polymer phase favors columnar ridges only on one side. • Combining cryo-SEM with EBSD links solidification theory with experiment.

Cryogenic EBSD reveals structure of directionally solidified ice–polymer composite

International Nuclear Information System (INIS)

Donius, Amalie E.; Obbard, Rachel W.; Burger, Joan N.; Hunger, Philipp M.; Baker, Ian; Doherty, Roger D.; Wegst, Ulrike G.K.

2014-01-01

Despite considerable research efforts on directionally solidified or freeze-cast materials in recent years, little fundamental knowledge has been gained that links model with experiment. In this contribution, the cryogenic characterization of directionally solidified polymer solutions illustrates, how powerful cryo-scanning electron microscopy combined with electron backscatter diffraction is for the structural characterization of ice–polymer composite materials. Under controlled sublimation, the freeze-cast polymer scaffold structure is revealed and imaged with secondary electrons. Electron backscatter diffraction fabric analysis shows that the ice crystals, which template the polymer scaffold and create the lamellar structure, have a-axes oriented parallel to the direction of solidification and the c-axes perpendicular to it. These results indicate the great potential of both cryo-scanning electron microscopy and cryo-electron backscatter diffraction in gaining fundamental knowledge of structure–property–processing correlations. - Highlights: • Cryo-SEM of freeze-cast polymer solution reveals an ice-templated structure. • Cryo-EBSD reveals the ice crystal a-axis to parallel the solidification direction. • The honeycomb-like polymer phase favors columnar ridges only on one side. • Combining cryo-SEM with EBSD links solidification theory with experiment

Pragmatic electrical engineering fundamentals

CERN Document Server

Eccles, William

2011-01-01

Pragmatic Electrical Engineering: Fundamentals introduces the fundamentals of the energy-delivery part of electrical systems. It begins with a study of basic electrical circuits and then focuses on electrical power. Three-phase power systems, transformers, induction motors, and magnetics are the major topics.All of the material in the text is illustrated with completely-worked examples to guide the student to a better understanding of the topics. This short lecture book will be of use at any level of engineering, not just electrical. Its goal is to provide the practicing engineer with a practi

Physical-mechanical image of the cell surface on the base of AFM data in contact mode

Science.gov (United States)

Starodubtseva, M. N.; Starodubtsev, I. E.; Yegorenkov, N. I.; Kuzhel, N. S.; Konstantinova, E. E.; Chizhik, S. A.

2017-10-01

Physical and mechanical properties of the cell surface are well-known markers of a cell state. The complex of the parameters characterizing the cell surface properties, such as the elastic modulus (E), the parameters of adhesive (Fa), and friction (Ff) forces can be measured using atomic force microscope (AFM) in a contact mode and form namely the physical-mechanical image of the cell surface that is a fundamental element of the cell mechanical phenotype. The paper aims at forming the physical-mechanical images of the surface of two types of glutaraldehyde-fixed cancerous cells (human epithelial cells of larynx carcinoma, HEp-2c cells, and breast adenocarcinoma, MCF-7 cells) based on the data obtained by AFM in air and revealing the basic difference between them. The average values of friction, elastic and adhesive forces, and the roughness of lateral force maps, as well as dependence of the fractal dimension of lateral force maps on Z-scale factor have been studied. We have revealed that the response of microscale areas of the HEp-2c cell surface having numerous microvilli to external mechanical forces is less expressed and more homogeneous in comparison with the response of MCF-7 cell surface.

Fundamental investigations in the barite flotation using the radionuclide technique

International Nuclear Information System (INIS)

Schmitz, J.; Wiese, K.; Hunsinger, H.

1977-01-01

The application of radioactive tracers in flotation is described taking the example of barite/silicate separation in a mechanically improved laboratory cell. The particular suitability of the radionuclide technique is not only brought out in the field of fundamental investigations, but also in the determination of dynamic systems data. The labelling of the liquid phase was done with Na 24 whereas useful mineral and gangue were traced by means of neutron-induced double-labelling. The necessary labelling, measuring and evaluating technique is described. (orig.) [de

Mechanics

CERN Document Server

Hartog, J P Den

1961-01-01

First published over 40 years ago, this work has achieved the status of a classic among introductory texts on mechanics. Den Hartog is known for his lively, discursive and often witty presentations of all the fundamental material of both statics and dynamics (and considerable more advanced material) in new, original ways that provide students with insights into mechanical relationships that other books do not always succeed in conveying. On the other hand, the work is so replete with engineering applications and actual design problems that it is as valuable as a reference to the practicing e

On the fundamental equation of nonequilibrium statistical physics—Nonequilibrium entropy evolution equation and the formula for entropy production rate

Institute of Scientific and Technical Information of China (English)

无

2010-01-01

another entropy increase rate, obtained a theoretical expression for unifying thermodynamic degradation and self-organizing evolution, and revealed that the entropy diffusion mechanism caused the system to approach to equilibrium. As application, we used these entropy formulas in calculating and discussing some actual physical topics in the nonequilibrium and stationary states. All these derivations and results are unified and rigorous from the new fundamental equation without adding any extra new assumption.

Characteristics of the Motor Units during Sternocleidomastoid Isometric Flexion among Patients with Mechanical Neck Disorder and Asymptomatic Individuals.

Directory of Open Access Journals (Sweden)

Chia-Chi Yang

Full Text Available Mechanical neck disorder is a widespread and non-neurological musculoskeletal condition resulting from modern lifestyles. Presently, the fundamental electrophysiological properties of the motor units of the sternocleidomastoid muscles and the characteristics of the short-term synchronization of the motor unit in patients with neck pain are ambiguous. This study therefore aims to clarify the fundamental electrophysiological properties of the motor units of the sternocleidomastoid muscles in patients with mechanical neck disorder and in asymptomatic individuals. We further investigated whether alterations in the degree of motor unit short-term synchronization occur. The surface electrophysiological signals of the bilateral sternal heads of the sternocleidomastoid muscles of twelve patients with mechanical neck disorder and asymptomatic individuals were detected at 25% of the maximum voluntary contraction during cervical isometric flexion and then decomposed into individual motor unit action potential trains. We found that the patients with mechanical neck disorder showed significantly higher initial and mean firing rates of the sternocleidomastoid muscles and displayed substantially lower motor unit short-term synchronization values compared with the asymptomatic subjects. Consequently, these convincing findings support the assertion that patients with mechanical neck disorder display altered neuromuscular control strategies, such as the reinforcement of motor unit recruitment firing rates in the sternocleidomastoid muscles. The motor units of these patients also revealed neural recruitment strategies with relatively poor efficiency when executing the required motor tasks.

Characteristics of the Motor Units during Sternocleidomastoid Isometric Flexion among Patients with Mechanical Neck Disorder and Asymptomatic Individuals.

Science.gov (United States)

Yang, Chia-Chi; Su, Fong-Chin; Yang, Po-Ching; Lin, Hwai-Ting; Guo, Lan-Yuen

2016-01-01

Mechanical neck disorder is a widespread and non-neurological musculoskeletal condition resulting from modern lifestyles. Presently, the fundamental electrophysiological properties of the motor units of the sternocleidomastoid muscles and the characteristics of the short-term synchronization of the motor unit in patients with neck pain are ambiguous. This study therefore aims to clarify the fundamental electrophysiological properties of the motor units of the sternocleidomastoid muscles in patients with mechanical neck disorder and in asymptomatic individuals. We further investigated whether alterations in the degree of motor unit short-term synchronization occur. The surface electrophysiological signals of the bilateral sternal heads of the sternocleidomastoid muscles of twelve patients with mechanical neck disorder and asymptomatic individuals were detected at 25% of the maximum voluntary contraction during cervical isometric flexion and then decomposed into individual motor unit action potential trains. We found that the patients with mechanical neck disorder showed significantly higher initial and mean firing rates of the sternocleidomastoid muscles and displayed substantially lower motor unit short-term synchronization values compared with the asymptomatic subjects. Consequently, these convincing findings support the assertion that patients with mechanical neck disorder display altered neuromuscular control strategies, such as the reinforcement of motor unit recruitment firing rates in the sternocleidomastoid muscles. The motor units of these patients also revealed neural recruitment strategies with relatively poor efficiency when executing the required motor tasks.

Arithmetic fundamental groups and moduli of curves

International Nuclear Information System (INIS)

Makoto Matsumoto

2000-01-01

This is a short note on the algebraic (or sometimes called arithmetic) fundamental groups of an algebraic variety, which connects classical fundamental groups with Galois groups of fields. A large part of this note describes the algebraic fundamental groups in a concrete manner. This note gives only a sketch of the fundamental groups of the algebraic stack of moduli of curves. Some application to a purely topological statement, i.e., an obstruction to the subjectivity of Johnson homomorphisms in the mapping class groups, which comes from Galois group of Q, is explained. (author)

Constant physics and characteristics of fundamental constant

International Nuclear Information System (INIS)

Tarrach, R.

1998-01-01

We present some evidence which supports a surprising physical interpretation of the fundamental constants. First, we relate two of them through the renormalization group. This leaves as many fundamental constants as base units. Second, we introduce and a dimensional system of units without fundamental constants. Third, and most important, we find, while interpreting the units of the a dimensional system, that is all cases accessible to experimentation the fundamental constants indicate either discretization at small values or boundedness at large values of the corresponding physical quantity. (Author) 12 refs

The exact fundamental solution for the Benes tracking problem

Science.gov (United States)

Balaji, Bhashyam

2009-05-01

The universal continuous-discrete tracking problem requires the solution of a Fokker-Planck-Kolmogorov forward equation (FPKfe) for an arbitrary initial condition. Using results from quantum mechanics, the exact fundamental solution for the FPKfe is derived for the state model of arbitrary dimension with Benes drift that requires only the computation of elementary transcendental functions and standard linear algebra techniques- no ordinary or partial differential equations need to be solved. The measurement process may be an arbitrary, discrete-time nonlinear stochastic process, and the time step size can be arbitrary. Numerical examples are included, demonstrating its utility in practical implementation.

Quantum Mechanics as Classical Physics

OpenAIRE

Sebens, CT

2015-01-01

Here I explore a novel no-collapse interpretation of quantum mechanics which combines aspects of two familiar and well-developed alternatives, Bohmian mechanics and the many-worlds interpretation. Despite reproducing the empirical predictions of quantum mechanics, the theory looks surprisingly classical. All there is at the fundamental level are particles interacting via Newtonian forces. There is no wave function. However, there are many worlds.

Possible mechanism of adhesion in a mica supported phospholipid bilayer

International Nuclear Information System (INIS)

Pertsin, Alexander; Grunze, Michael

2014-01-01

Phospholipid bilayers supported on hydrophilic solids like silica and mica play a substantial role in fundamental studies and technological applications of phospholipid membranes. In both cases the molecular mechanism of adhesion between the bilayer and the support is of primary interest. Since the possibilities of experimental methods in this specific area are rather limited, the methods of computer simulation acquire great importance. In this paper we use the grand canonical Monte Carlo technique and an atomistic force field to simulate the behavior of a mica supported phospholipid bilayer in pure water as a function of the distance between the bilayer and the support. The simulation reveals a possible adhesion mechanism, where the adhesion is due to individual lipid molecules that protrude from the bilayer and form widely spaced links with the support. Simultaneously, the bilayer remains separated from the bilayer by a thin water interlayer which maintains the bilayer fluidity

Ion beam analysis fundamentals and applications

CERN Document Server

Nastasi, Michael; Wang, Yongqiang

2015-01-01

Ion Beam Analysis: Fundamentals and Applications explains the basic characteristics of ion beams as applied to the analysis of materials, as well as ion beam analysis (IBA) of art/archaeological objects. It focuses on the fundamentals and applications of ion beam methods of materials characterization.The book explains how ions interact with solids and describes what information can be gained. It starts by covering the fundamentals of ion beam analysis, including kinematics, ion stopping, Rutherford backscattering, channeling, elastic recoil detection, particle induced x-ray emission, and nucle

CORRELATIONS OF DISK AND JET EMISSION DEVIATING FROM THE FUNDAMENTAL PLANE

Energy Technology Data Exchange (ETDEWEB)

Lin, Da-Bin; Mu, Hui-Jun; Lu, Zu-Jia; Liang, En-Wei [GXU-NAOC Center for Astrophysics and Space Sciences, Department of Physics, Guangxi University, Nanning 530004 (China); Gu, Wei-Min; Ma, Ren-Yi, E-mail: lindabin@gxu.edu.cn [Department of Astronomy and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen, Fujian 361005 (China)

2015-07-01

The variability of the accretion rate, which is believed to induce the aperiodic variability of X-ray emission from disks, may affect the energy injection into a jet. In this spirit, a correlation between disk emission and jet emission can be formed even if the mean luminosity of disk emission remains constant. In this work, these correlations are found in the situation in which the luminosity of disk emission is variable and kept at a constant mean value. The obtained correlations may be shallower than that of the fundamental plane of black hole activity. In addition, the slope of correlation may increase with increasing observed frequency of jet emission. For the luminosities spaced over three days, the slope of correlation decreases with increasing black hole mass. The deviation of our found correlations from that of the fundamental plane is related to the suppression of variability in the jet emission in comparison with that in the disk emission. This mechanism may work in some sources in which shallower correlations have been reported. Moreover, it implies that luminosities used to estimate the relation of the fundamental plane should cover an appropriate timescale, in which the variability of jet emission is not significantly suppressed.

Nature of the fundamental band gap in GaNxP1-x alloys

International Nuclear Information System (INIS)

Shan, W.; Walukiewicz, W.; Yu, K. M.; Wu, J.; Ager, J. W. III; Haller, E. E.; Xin, H. P.; Tu, C. W.

2000-01-01

The optical properties of GaN x P 1-x alloys (0.007≤x≤0.031) grown by gas-source molecular-beam epitaxy have been studied. An absorption edge appears in GaN x P 1-x at energy below the indirect Γ V -X C transition in GaP, and the absorption edge shifts to lower energy with increasing N concentration. Strong photomodulation signals associated with the absorption edges in GaN x P 1-x indicate that a direct fundamental optical transition is taking place, revealing that the fundamental band gap has changed from indirect to direct. This N-induced transformation from indirect to direct band gap is explained in terms of an interaction between the highly localized nitrogen states and the extended states at the Γ conduction-band minimum. (c) 2000 American Institute of Physics

Research Update: Mechanical properties of metal-organic frameworks - Influence of structure and chemical bonding

Science.gov (United States)

Li, Wei; Henke, Sebastian; Cheetham, Anthony K.

2014-12-01

Metal-organic frameworks (MOFs), a young family of functional materials, have been attracting considerable attention from the chemistry, materials science, and physics communities. In the light of their potential applications in industry and technology, the fundamental mechanical properties of MOFs, which are of critical importance for manufacturing, processing, and performance, need to be addressed and understood. It has been widely accepted that the framework topology, which describes the overall connectivity pattern of the MOF building units, is of vital importance for the mechanical properties. However, recent advances in the area of MOF mechanics reveal that chemistry plays a major role as well. From the viewpoint of materials science, a deep understanding of the influence of chemical effects on MOF mechanics is not only highly desirable for the development of novel functional materials with targeted mechanical response, but also for a better understanding of important properties such as structural flexibility and framework breathing. The present work discusses the intrinsic connection between chemical effects and the mechanical behavior of MOFs through a number of prototypical examples.

Different Variants of Fundamental Portfolio

Directory of Open Access Journals (Sweden)

Tarczyński Waldemar

2014-06-01

Full Text Available The paper proposes the fundamental portfolio of securities. This portfolio is an alternative for the classic Markowitz model, which combines fundamental analysis with portfolio analysis. The method’s main idea is based on the use of the TMAI1 synthetic measure and, in limiting conditions, the use of risk and the portfolio’s rate of return in the objective function. Different variants of fundamental portfolio have been considered under an empirical study. The effectiveness of the proposed solutions has been related to the classic portfolio constructed with the help of the Markowitz model and the WIG20 market index’s rate of return. All portfolios were constructed with data on rates of return for 2005. Their effectiveness in 2006- 2013 was then evaluated. The studied period comprises the end of the bull market, the 2007-2009 crisis, the 2010 bull market and the 2011 crisis. This allows for the evaluation of the solutions’ flexibility in various extreme situations. For the construction of the fundamental portfolio’s objective function and the TMAI, the study made use of financial and economic data on selected indicators retrieved from Notoria Serwis for 2005.

Combined quantum-mechanics/molecular-mechanics dynamics simulation of A-DNA double strands irradiated by ultra-low-energy carbon ions

Energy Technology Data Exchange (ETDEWEB)

Ngaojampa, C.; Nimmanpipug, P. [Computer Simulation and Modeling Laboratory (CSML), Department of Chemistry and Center for Innovation Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@fnrf.science.cmu.ac.t [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Anuntalabhochai, S. [Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Lee, V.S., E-mail: vannajan@gmail.co [Computer Simulation and Modeling Laboratory (CSML), Department of Chemistry and Center for Innovation Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

2011-02-15

In order to promote understanding of the fundamentals of ultra-low-energy ion interaction with DNA, molecular dynamics simulations using combined quantum-mechanics/molecular-mechanics of poly-AT and poly-GC A-DNA double strands irradiated by <200 eV carbon ions were performed to investigate the molecular implications of mutation bias. The simulations were focused on the responses of the DNA backbones and nitrogenous bases to irradiation. Analyses of the root mean square displacements of the backbones and non-hydrogen atoms of base rings of the simulated DNA structure after irradiation revealed a potential preference of DNA double strand separation, dependent on the irradiating energy. The results show that for the backbones, the large difference in the displacement between poly-GC and poly-AT in the initial time period could be the reason for the backbone breakage; for the nitrogenous base pairs, A-T is 30% more sensitive or vulnerable to ion irradiation than G-C, demonstrating a preferential, instead of random, effect of irradiation-induced mutation.

Combined quantum-mechanics/molecular-mechanics dynamics simulation of A-DNA double strands irradiated by ultra-low-energy carbon ions

International Nuclear Information System (INIS)

Ngaojampa, C.; Nimmanpipug, P.; Yu, L.D.; Anuntalabhochai, S.; Lee, V.S.

2011-01-01

In order to promote understanding of the fundamentals of ultra-low-energy ion interaction with DNA, molecular dynamics simulations using combined quantum-mechanics/molecular-mechanics of poly-AT and poly-GC A-DNA double strands irradiated by <200 eV carbon ions were performed to investigate the molecular implications of mutation bias. The simulations were focused on the responses of the DNA backbones and nitrogenous bases to irradiation. Analyses of the root mean square displacements of the backbones and non-hydrogen atoms of base rings of the simulated DNA structure after irradiation revealed a potential preference of DNA double strand separation, dependent on the irradiating energy. The results show that for the backbones, the large difference in the displacement between poly-GC and poly-AT in the initial time period could be the reason for the backbone breakage; for the nitrogenous base pairs, A-T is 30% more sensitive or vulnerable to ion irradiation than G-C, demonstrating a preferential, instead of random, effect of irradiation-induced mutation.

A Systems Biology Approach Reveals Converging Molecular Mechanisms that Link Different POPs to Common Metabolic Diseases.

Science.gov (United States)

Ruiz, Patricia; Perlina, Ally; Mumtaz, Moiz; Fowler, Bruce A

2016-07-01

A number of epidemiological studies have identified statistical associations between persistent organic pollutants (POPs) and metabolic diseases, but testable hypotheses regarding underlying molecular mechanisms to explain these linkages have not been published. We assessed the underlying mechanisms of POPs that have been associated with metabolic diseases; three well-known POPs [2,3,7,8-tetrachlorodibenzodioxin (TCDD), 2,2´,4,4´,5,5´-hexachlorobiphenyl (PCB 153), and 4,4´-dichlorodiphenyldichloroethylene (p,p´-DDE)] were studied. We used advanced database search tools to delineate testable hypotheses and to guide laboratory-based research studies into underlying mechanisms by which this POP mixture could produce or exacerbate metabolic diseases. For our searches, we used proprietary systems biology software (MetaCore™/MetaDrug™) to conduct advanced search queries for the underlying interactions database, followed by directional network construction to identify common mechanisms for these POPs within two or fewer interaction steps downstream of their primary targets. These common downstream pathways belong to various cytokine and chemokine families with experimentally well-documented causal associations with type 2 diabetes. Our systems biology approach allowed identification of converging pathways leading to activation of common downstream targets. To our knowledge, this is the first study to propose an integrated global set of step-by-step molecular mechanisms for a combination of three common POPs using a systems biology approach, which may link POP exposure to diseases. Experimental evaluation of the proposed pathways may lead to development of predictive biomarkers of the effects of POPs, which could translate into disease prevention and effective clinical treatment strategies. Ruiz P, Perlina A, Mumtaz M, Fowler BA. 2016. A systems biology approach reveals converging molecular mechanisms that link different POPs to common metabolic diseases. Environ

Mechanics over micro and nano scales

CERN Document Server

Chakraborty, Suman

2011-01-01

Discusses the fundaments of mechanics over micro and nano scales in a level accessible to multi-disciplinary researchers, with a balance of mathematical details and physical principles Covers life sciences and chemistry for use in emerging applications related to mechanics over small scales Demonstrates the explicit interconnection between various scale issues and the mechanics of miniaturized systems

PREFACE: Fundamental Neutron Physics: Introduction and Overview Fundamental Neutron Physics: Introduction and Overview

Science.gov (United States)

Holstein, Barry R.

2009-10-01

fundamental nature, the structure of the neutron itself can be used to probe hadronic structure, via measurement of its electromagnetic form factors and/or polarizabilities. This aspect of neutron physics is discussed in the article by Daniel Phillips. In a set of measurements at Grenoble, the neutron has been used to study its quantum mechanical gravitational bound state in the vicinity of the Earth's surface. This work is described in the article by Stefan Baessler. Finally, possible beyond standard model physics is probed by experimental searches for neutron-antineutron oscillations, as discussed in the article by Rabi Mohaptatra. There exist many other areas wherein the neutron has been used as a probe of fundamental pieces of contemporary physics. Examples include the use of neutron interferometry to measure the Earth's rotation and gravitational field and the recent use of light cone methods to study the transverse charge distribution of the neutron. Indeed, a full report on all such aspects could fill an entire volume of Journal of Physics G: Nuclear and Particle Physics. The six articles which appear here in this focus section are presented rather as a brief overview, to possibly whet the appetite of the reader for such work. Hungrier readers can fill their plate with additional and more detailed information available in the many references cited by the focus articles or in more extensive discussions available elsewhere. An example is the article on experiments in fundamental neutron physics by Jeff Nico and Mike Snow published in Annual Reviews of Nuclear and Particle Science 2005 55 27-69, but there are many others.

Fibrillation mechanism of a model intrinsically disordered protein revealed by 2D correlation deep UV resonance Raman spectroscopy.

Science.gov (United States)

Sikirzhytski, Vitali; Topilina, Natalya I; Takor, Gaius A; Higashiya, Seiichiro; Welch, John T; Uversky, Vladimir N; Lednev, Igor K

2012-05-14

Understanding of numerous biological functions of intrinsically disordered proteins (IDPs) is of significant interest to modern life science research. A large variety of serious debilitating diseases are associated with the malfunction of IDPs including neurodegenerative disorders and systemic amyloidosis. Here we report on the molecular mechanism of amyloid fibrillation of a model IDP (YE8) using 2D correlation deep UV resonance Raman spectroscopy. YE8 is a genetically engineered polypeptide, which is completely unordered at neutral pH yet exhibits all properties of a fibrillogenic protein at low pH. The very first step of the fibrillation process involves structural rearrangements of YE8 at the global structure level without the detectable appearance of secondary structural elements. The formation of β-sheet species follows the global structural changes and proceeds via the simultaneous formation of turns and β-strands. The kinetic mechanism revealed is an important new contribution to understanding of the general fibrillation mechanism proposed for IDP.

Fundamentals of piping design

CERN Document Server

Smith, Peter

2013-01-01

Written for the piping engineer and designer in the field, this two-part series helps to fill a void in piping literature,since the Rip Weaver books of the '90s were taken out of print at the advent of the Computer Aid Design(CAD) era. Technology may have changed, however the fundamentals of piping rules still apply in the digitalrepresentation of process piping systems. The Fundamentals of Piping Design is an introduction to the designof piping systems, various processes and the layout of pipe work connecting the major items of equipment forthe new hire, the engineering student and the vetera

The Problems of Realizing the Innovative Potential of Science and Mechanisms for their Solution

Directory of Open Access Journals (Sweden)

Ianchenko Zinayida B.

2017-06-01

Full Text Available The aim of the article is revealing reasons for the low payoff of science in terms of the effectiveness of the research activity and demand for its results in economic spheres, identifying problems in the innovation activity of research institutions and reasons for their arising, searching for fundamental approaches to the development of a strategy and mechanisms for realization of the innovative potential of science to strengthen its position in the real sector. The study used general scientific methods, including: systems approach — to systematize the problems of the innovation activity of research institutions; methods of theoretical generalization — to study the theoretical principles of the scientific and innovation activity; methods of analysis and synthesis — to search for fundamental approaches to the development of mechanisms for realization of the innovative potential of science. The used concepts of scientific activity and innovations are generalized. The author’s definition of the term “innovation” is proposed. The main reasons of the minor impact of science on the economy are systematized, the mechanisms for their elimination are offered. Based on the comprehensive analysis of the reasons for losing by science its impact on the economy, the ways of realizing the innovative potential of science are improved. The results of the research can be used in reforming domestic scientific research institutions.

Maximizing the return on taxpayers' investments in fundamental biomedical research.

Science.gov (United States)

Lorsch, Jon R

2015-05-01

The National Institute of General Medical Sciences (NIGMS) at the U.S. National Institutes of Health has an annual budget of more than $2.3 billion. The institute uses these funds to support fundamental biomedical research and training at universities, medical schools, and other institutions across the country. My job as director of NIGMS is to work to maximize the scientific returns on the taxpayers' investments. I describe how we are optimizing our investment strategies and funding mechanisms, and how, in the process, we hope to create a more efficient and sustainable biomedical research enterprise.

Structure reveals regulatory mechanisms of a MaoC-like hydratase from Phytophthora capsici involved in biosynthesis of polyhydroxyalkanoates (PHAs).

Science.gov (United States)

Wang, Huizheng; Zhang, Kai; Zhu, Jie; Song, Weiwei; Zhao, Li; Zhang, Xiuguo

2013-01-01

Polyhydroxyalkanoates (PHAs) have attracted increasing attention as "green plastic" due to their biodegradable, biocompatible, thermoplastic, and mechanical properties, and considerable research has been undertaken to develop low cost/high efficiency processes for the production of PHAs. MaoC-like hydratase (MaoC), which belongs to (R)-hydratase involved in linking the β-oxidation and the PHA biosynthetic pathways, has been identified recently. Understanding the regulatory mechanisms of (R)-hydratase catalysis is critical for efficient production of PHAs that promise synthesis an environment-friendly plastic. We have determined the crystal structure of a new MaoC recognized from Phytophthora capsici. The crystal structure of the enzyme was solved at 2.00 Å resolution. The structure shows that MaoC has a canonical (R)-hydratase fold with an N-domain and a C-domain. Supporting its dimerization observed in structure, MaoC forms a stable homodimer in solution. Mutations that disrupt the dimeric MaoC result in a complete loss of activity toward crotonyl-CoA, indicating that dimerization is required for the enzymatic activity of MaoC. Importantly, structure comparison reveals that a loop unique to MaoC interacts with an α-helix that harbors the catalytic residues of MaoC. Deletion of the loop enhances the enzymatic activity of MaoC, suggesting its inhibitory role in regulating the activity of MaoC. The data in our study reveal the regulatory mechanism of an (R)-hydratase, providing information on enzyme engineering to produce low cost PHAs.

Linear models for assessing mechanisms of sperm competition: the trouble with transformations.

Science.gov (United States)

Eggert, Anne-Katrin; Reinhardt, Klaus; Sakaluk, Scott K

2003-01-01

Although sperm competition is a pervasive selective force shaping the reproductive tactics of males, the mechanisms underlying different patterns of sperm precedence remain obscure. Parker et al. (1990) developed a series of linear models designed to identify two of the more basic mechanisms: sperm lotteries and sperm displacement; the models can be tested experimentally by manipulating the relative numbers of sperm transferred by rival males and determining the paternity of offspring. Here we show that tests of the model derived for sperm lotteries can result in misleading inferences about the underlying mechanism of sperm precedence because the required inverse transformations may lead to a violation of fundamental assumptions of linear regression. We show that this problem can be remedied by reformulating the model using the actual numbers of offspring sired by each male, and log-transforming both sides of the resultant equation. Reassessment of data from a previous study (Sakaluk and Eggert 1996) using the corrected version of the model revealed that we should not have excluded a simple sperm lottery as a possible mechanism of sperm competition in decorated crickets, Gryllodes sigillatus.

The fundamental role of ecological feedback mechanisms for the adaptive management of seagrass ecosystems - a review.

Science.gov (United States)

Maxwell, Paul S; Eklöf, Johan S; van Katwijk, Marieke M; O'Brien, Katherine R; de la Torre-Castro, Maricela; Boström, Christoffer; Bouma, Tjeerd J; Krause-Jensen, Dorte; Unsworth, Richard K F; van Tussenbroek, Brigitta I; van der Heide, Tjisse

2017-08-01

Seagrass meadows are vital ecosystems in coastal zones worldwide, but are also under global threat. One of the major hurdles restricting the success of seagrass conservation and restoration is our limited understanding of ecological feedback mechanisms. In these ecosystems, multiple, self-reinforcing feedbacks can undermine conservation efforts by masking environmental impacts until the decline is precipitous, or alternatively they can inhibit seagrass recovery in spite of restoration efforts. However, no clear framework yet exists for identifying or dealing with feedbacks to improve the management of seagrass ecosystems. Here we review the causes and consequences of multiple feedbacks between seagrass and biotic and/or abiotic processes. We demonstrate how feedbacks have the potential to impose or reinforce regimes of either seagrass dominance or unvegetated substrate, and how the strength and importance of these feedbacks vary across environmental gradients. Although a myriad of feedbacks have now been identified, the co-occurrence and likely interaction among feedbacks has largely been overlooked to date due to difficulties in analysis and detection. Here we take a fundamental step forward by modelling the interactions among two distinct above- and belowground feedbacks to demonstrate that interacting feedbacks are likely to be important for ecosystem resilience. On this basis, we propose a five-step adaptive management plan to address feedback dynamics for effective conservation and restoration strategies. The management plan provides guidance to aid in the identification and prioritisation of likely feedbacks in different seagrass ecosystems. © 2016 Cambridge Philosophical Society.

Investigating fundamental properties of wind turbine wake structure using particle image velocimetry

Energy Technology Data Exchange (ETDEWEB)

Whale, J. [Univ. of Edinburgh, Dept. of Mechanical Engineering, Edinburgh (United Kingdom)

1997-08-01

Low Reynolds number flow visualization tests are often used for showing the flow pattern changes associated with changes in lift-coefficients at a higher Reynolds number. In wind turbine studies, analysis of measured wake structures at small scale may reveal fundamental properties of the wake which will offer wake modellers a more complete understanding of rotor flows. Measurements are presented from experiments on a model wind turbine rig conducted in a water channel. The laser-optics technique of Particle Image Velocimetry (PIV) is used to make simultaneous multi-point measurements of the wake flow behind small-scale rotors. Analysis of the PIV data shows trends in velocity and vorticity structure in the wake. Study of the flow close to the rotor plane reveals information on stalled flow and blade performance. (au)

Damage analysis and fundamental studies. Quarterly progress report, July--September 1978

Energy Technology Data Exchange (ETDEWEB)

Zwilsky, Klaus M.

1979-05-01

This report is the third in a series of Quarterly Technical Progress Reports on Damage Analysis and Fundamental Studies (DAFS) which is one element of the Fusion Reactor Materials Program, conducted in support of the Magnetic Fusion Energy Program. This report is organized along topical lines in parallel to Section II, Damage Analysis and Fundamental Studies (DOE/ET-0032/2), of the Fusion Reactor Materials Program Plan so that activities and accomplishments may be followed readily relative to that Program Plan. Thus, the work of a given laboratory may appear throughout the report. Chapters 1 and 2 report topics which are generic to all of the DAFS Program: DAFS Task Group Activities and Irradiation Test Facilities, respectively. Chapters 3, 4, and 5 report the work that is specific to each of the subtasks around which the program is structured: A) Environmental Characterization, B) Damage Production, and C) Damage Microstructure Evolution and Mechanical Behavior.

Proposed experiment to test fundamentally binary theories

Science.gov (United States)

Kleinmann, Matthias; Vértesi, Tamás; Cabello, Adán

2017-09-01

Fundamentally binary theories are nonsignaling theories in which measurements of many outcomes are constructed by selecting from binary measurements. They constitute a sensible alternative to quantum theory and have never been directly falsified by any experiment. Here we show that fundamentally binary theories are experimentally testable with current technology. For that, we identify a feasible Bell-type experiment on pairs of entangled qutrits. In addition, we prove that, for any n , quantum n -ary correlations are not fundamentally (n -1 ) -ary. For that, we introduce a family of inequalities that hold for fundamentally (n -1 ) -ary theories but are violated by quantum n -ary correlations.

Structure and mechanism of calmodulin binding to a signaling sphingolipid reveal new aspects of lipid-protein interactions

Science.gov (United States)

Kovacs, Erika; Harmat, Veronika; Tóth, Judit; Vértessy, Beáta G.; Módos, Károly; Kardos, József; Liliom, Károly

2010-01-01

Lipid-protein interactions are rarely characterized at a structural molecular level due to technical difficulties; however, the biological significance of understanding the mechanism of these interactions is outstanding. In this report, we provide mechanistic insight into the inhibitory complex formation of the lipid mediator sphingosylphosphorylcholine with calmodulin, the most central and ubiquitous regulator protein in calcium signaling. We applied crystallographic, thermodynamic, kinetic, and spectroscopic approaches using purified bovine calmodulin and bovine cerebral microsomal fraction to arrive at our conclusions. Here we present 1) a 1.6-Å resolution crystal structure of their complex, in which the sphingolipid occupies the conventional hydrophobic binding site on calmodulin; 2) a peculiar stoichiometry-dependent binding process: at low or high protein-to-lipid ratio calmodulin binds lipid micelles or a few lipid molecules in a compact globular conformation, respectively, and 3) evidence that the sphingolipid displaces calmodulin from its targets on cerebral microsomes. We have ascertained the specificity of the interaction using structurally related lipids as controls. Our observations reveal the structural basis of selective calmodulin inhibition by the sphingolipid. On the basis of the crystallographic and biophysical characterization of the calmodulin–sphingosylphosphorylcholine interaction, we propose a novel lipid-protein binding model, which might be applicable to other interactions as well.—Kovacs, E., Harmat, V., Tóth, J., Vértessy, B. G., Módos, K., Kardos, J., Liliom, K. Structure and mechanism of calmodulin binding to a signaling sphingolipid reveal new aspects of lipid-protein interactions. PMID:20522785

Fundamentals of electronic image processing

CERN Document Server

Weeks, Arthur R

1996-01-01

This book is directed to practicing engineers and scientists who need to understand the fundamentals of image processing theory and algorithms to perform their technical tasks. It is intended to fill the gap between existing high-level texts dedicated to specialists in the field and the need for a more practical, fundamental text on image processing. A variety of example images are used to enhance reader understanding of how particular image processing algorithms work.

Research Update: Mechanical properties of metal-organic frameworks – Influence of structure and chemical bonding

Directory of Open Access Journals (Sweden)

Wei Li

2014-12-01

Full Text Available Metal-organic frameworks (MOFs, a young family of functional materials, have been attracting considerable attention from the chemistry, materials science, and physics communities. In the light of their potential applications in industry and technology, the fundamental mechanical properties of MOFs, which are of critical importance for manufacturing, processing, and performance, need to be addressed and understood. It has been widely accepted that the framework topology, which describes the overall connectivity pattern of the MOF building units, is of vital importance for the mechanical properties. However, recent advances in the area of MOF mechanics reveal that chemistry plays a major role as well. From the viewpoint of materials science, a deep understanding of the influence of chemical effects on MOF mechanics is not only highly desirable for the development of novel functional materials with targeted mechanical response, but also for a better understanding of important properties such as structural flexibility and framework breathing. The present work discusses the intrinsic connection between chemical effects and the mechanical behavior of MOFs through a number of prototypical examples.

Homeschooling and religious fundamentalism

Directory of Open Access Journals (Sweden)

Robert Kunzman

2010-10-01

Full Text Available This article considers the relationship between homeschooling and religious fundamentalism by focusing on their intersection in the philosophies and practices of conservative Christian homeschoolers in the United States. Homeschooling provides an ideal educational setting to support several core fundamentalist principles: resistance to contemporary culture; suspicion of institutional authority and professional expertise; parental control and centrality of the family; and interweaving of faith and academics. It is important to recognize, however, that fundamentalism exists on a continuum; conservative religious homeschoolers resist liberal democratic values to varying degrees, and efforts to foster dialogue and accommodation with religious homeschoolers can ultimately help strengthen the broader civic fabric.

Fundamental Perspectives on Supply Chain Management

NARCIS (Netherlands)

Omta, S.W.F.; Hoenen, S.J.

2012-01-01

The aim of the present literature study is to find the fundamental perspectives/models in the realm of supply chain management and to investigate whether they can be extended based on recent literature findings. The fundamental perspectives were found using a two-tier snowball collection method,

EU criminal law and fundamental rights

NARCIS (Netherlands)

de Hert, Paul; Mitsilegas, V.; Bergström, M.; Konstadinides, Th.

2016-01-01

The chapter first offers a background analysis to EU fundamental rights law, recalling the historical affirmation of the protection of fundamental rights as a EU concern, and the important innovation brought about by the Lisbon Treaty (section 2) and the multiplicity of actors involved in the system

Fundamental symmetries and interactions-selected topics

NARCIS (Netherlands)

Jungmann, Klaus P.

2015-01-01

In the field of fundamental interactions and symmetries numerous experiments are underway or planned in order to verify the standard model in particle physics, to search for possible extensions to it or to exploit the standard model for extracting most precise values for fundamental constants. We

Fundamental partial compositeness

DEFF Research Database (Denmark)

Sannino, Francesco; Strumia, Alessandro; Tesi, Andrea

2016-01-01

We construct renormalizable Standard Model extensions, valid up to the Planck scale, that give a composite Higgs from a new fundamental strong force acting on fermions and scalars. Yukawa interactions of these particles with Standard Model fermions realize the partial compositeness scenario. Unde...

Highly-stretchable 3D-architected Mechanical Metamaterials

Science.gov (United States)

Jiang, Yanhui; Wang, Qiming

2016-09-01

Soft materials featuring both 3D free-form architectures and high stretchability are highly desirable for a number of engineering applications ranging from cushion modulators, soft robots to stretchable electronics; however, both the manufacturing and fundamental mechanics are largely elusive. Here, we overcome the manufacturing difficulties and report a class of mechanical metamaterials that not only features 3D free-form lattice architectures but also poses ultrahigh reversible stretchability (strain > 414%), 4 times higher than that of the existing counterparts with the similar complexity of 3D architectures. The microarchitected metamaterials, made of highly stretchable elastomers, are realized through an additive manufacturing technique, projection microstereolithography, and its postprocessing. With the fabricated metamaterials, we reveal their exotic mechanical behaviors: Under large-strain tension, their moduli follow a linear scaling relationship with their densities regardless of architecture types, in sharp contrast to the architecture-dependent modulus power-law of the existing engineering materials; under large-strain compression, they present tunable negative-stiffness that enables ultrahigh energy absorption efficiencies. To harness their extraordinary stretchability and microstructures, we demonstrate that the metamaterials open a number of application avenues in lightweight and flexible structure connectors, ultraefficient dampers, 3D meshed rehabilitation structures and stretchable electronics with designed 3D anisotropic conductivity.

"Gear mechanism" of bariatric interventions revealed by untargeted metabolomics.

Science.gov (United States)

Samczuk, Paulina; Luba, Magdalena; Godzien, Joanna; Mastrangelo, Annalaura; Hady, Hady Razak; Dadan, Jacek; Barbas, Coral; Gorska, Maria; Kretowski, Adam; Ciborowski, Michal

2018-03-20

Mechanisms responsible for metabolic gains after bariatric surgery are not entirely clear. The purpose of this study was evaluation of metabolic changes after laparoscopic Roux-en-Y gastric bypass or laparoscopic sleeve gastrectomy in semi-annual follow up. The study participants were selected from obese patients with T2DM who underwent one of the mentioned bariatric procedures. Serum metabolic fingerprinting by use of liquid and gas chromatography with mass spectrometry detection was performed on samples obtained from studied patients before, one, and six months post-surgery. Performed analyses resulted in 49 significant and identified metabolites. Comparison of the two described procedures has allowed to detect metabolites linked with numerous pathways, processes and diseases. Based on the metabolites detected and pathways affected, we propose a "gear mechanism" showing molecular changes evoked by both bariatric procedures. Critical evaluation of clinical data and obtained metabolomics results enables us to conclude that both procedures are very similar in terms of general clinical outcome, but they strongly differ from each other in molecular mechanisms leading to the final effect. For the first time general metabolic effect of bariatric procedures is described. New hypotheses concerning molecular mechanisms induced by bariatric surgeries and new gut microbiota modulations are presented. Copyright © 2018 Elsevier B.V. All rights reserved.

Mechanical strain can switch the sign of quantum capacitance from positive to negative.

Science.gov (United States)

Hanlumyuang, Yuranan; Li, Xiaobao; Sharma, Pradeep

2014-11-14

Quantum capacitance is a fundamental quantity that can directly reveal many-body interactions among electrons and is expected to play a critical role in nanoelectronics. One of the many tantalizing recent physical revelations about quantum capacitance is that it can possess a negative value, hence allowing for the possibility of enhancing the overall capacitance in some particular material systems beyond the scaling predicted by classical electrostatics. Using detailed quantum mechanical simulations, we found an intriguing result that mechanical strains can tune both signs and values of quantum capacitance. We used a small coaxially gated carbon nanotube as a paradigmatical capacitor system and showed that, for the range of mechanical strain considered, quantum capacitance can be adjusted from very large positive to very large negative values (in the order of plus/minus hundreds of attofarads), compared to the corresponding classical geometric value (0.31035 aF). This finding opens novel avenues in designing quantum capacitance for applications in nanosensors, energy storage, and nanoelectronics.

The mechanics of anaphase B in a basidiomycete as revealed by laser microbeam microsurgery

International Nuclear Information System (INIS)

Bayles, C.J.; Aist, J.R.; Berns, M.W.

1993-01-01

Bayles, C. J., Aist, J. R., and Berns, M. W. 1993. The mechanics of anaphase B in a basidiomycete as revealed by laser microbeam microsurgery. Experimental Mycology 17, 191-199. Cytoplasmic forces were found to be actively pulling on the spindle pole bodies during anaphase B in the dikaryotic, basidiomycete fungus, Helicobasidium mompa. When the spindle of one nucleus was severed with a laser microbeam at mid anaphase B, its two spindle pole bodies separated at a much faster rate than did those of the intact spindle in the other nucleus of the same cell. Since astral microtubule populations apparently reach their maximum during anaphase B in this fungus, we suggest that these microtubules may be involved in the cytoplasmic pulling forces. The spindle appears to act primarily as a governor, regulating the rate at which the spindle pole bodies are separated

Modern Thermodynamics with Statistical Mechanics

CERN Document Server

Helrich, Carl S

2009-01-01

With the aim of presenting thermodynamics in as simple and as unified a form as possible, this textbook starts with an introduction to the first and second laws and then promptly addresses the complete set of the potentials in a subsequent chapter and as a central theme throughout. Before discussing modern laboratory measurements, the book shows that the fundamental quantities sought in the laboratory are those which are required for determining the potentials. Since the subjects of thermodynamics and statistical mechanics are a seamless whole, statistical mechanics is treated as integral part of the text. Other key topics such as irreversibility, the ideas of Ilya Prigogine, chemical reaction rates, equilibrium of heterogeneous systems, and transition-state theory serve to round out this modern treatment. An additional chapter covers quantum statistical mechanics due to active current research in Bose-Einstein condensation. End-of-chapter exercises, chapter summaries, and an appendix reviewing fundamental pr...

Computational mechanics research at ONR

International Nuclear Information System (INIS)

Kushner, A.S.

1986-01-01

Computational mechanics is not an identified program at the Office of Naval Research (ONR), but rather plays a key role in the Solid Mechanics, Fluid Mechanics, Energy Conversion, and Materials Science programs. The basic philosophy of the Mechanics Division at ONR is to support fundamental research which expands the basis for understanding, predicting, and controlling the behavior of solid and fluid materials and systems at the physical and geometric scales appropriate to the phenomena of interest. It is shown in this paper that a strong commonalty of computational mechanics drivers exists for the forefront research areas in both solid and fluid mechanics

Magnetism From Fundamentals to Nanoscale Dynamics

CERN Document Server

Stöhr, Joachim

2006-01-01

The present text book gives an comprehensive account of magnetism, spanning the historical development, the physical foundations and the continuing research underlying the field, one of the oldest yet still vibrant field of physics. It covers both the classical and quantum mechanical aspects of magnetism and novel experimental techniques. Perhaps uniquely, it also discusses spin transport and magnetization dynamics phenomena associated with atomically and spin engineered nano-structures against the backdrop of spintronics and magnetic storage and memory applications. Despite the existence of various books on the topic, a fresh text book that reviews the fundamental physical concepts and uses them in a coherent fashion to explain some of the forefront problems and applications today was thought useful by the authors and their colleagues. Magnetism is written for students on the late undergraduate and the graduate levels and should also serve as a state-of-the-art reference for scientists in academia and resear...

Fundamental physics in particle traps

International Nuclear Information System (INIS)

Quint, Wolfgang; Vogel, Manuel

2014-01-01

The individual topics are covered by leading experts in the respective fields of research. Provides readers with present theory and experiments in this field. A useful reference for researchers. This volume provides detailed insight into the field of precision spectroscopy and fundamental physics with particles confined in traps. It comprises experiments with electrons and positrons, protons and antiprotons, antimatter and highly charged ions, together with corresponding theoretical background. Such investigations represent stringent tests of quantum electrodynamics and the Standard model, antiparticle and antimatter research, test of fundamental symmetries, constants, and their possible variations with time and space. They are key to various aspects within metrology such as mass measurements and time standards, as well as promising to further developments in quantum information processing. The reader obtains a valuable source of information suited for beginners and experts with an interest in fundamental studies using particle traps.

Mechanical design engineering handbook

CERN Document Server

Childs, Peter R N

2013-01-01

Mechanical Design Engineering Handbook is a straight-talking and forward-thinking reference covering the design, specification, selection, use and integration of machine elements fundamental to a wide range of engineering applications. Develop or refresh your mechanical design skills in the areas of bearings, shafts, gears, seals, belts and chains, clutches and brakes, springs, fasteners, pneumatics and hydraulics, amongst other core mechanical elements, and dip in for principles, data and calculations as needed to inform and evaluate your on-the-job decisions. Covering the full spectrum

Prologue to super quantum mechanics something is rotten in the state of quantum mechanics

CERN Document Server

Vaguine, Victor

2012-01-01

Since its foundation more than eight decades ago, quantum mechanics has been plagued by enigmas, mysteries and paradoxes and held hostage by quantum positivism. This fact strongly suggests that something is fundamentally wrong with the quantum mechanics paradigm. The best scientific minds, such as Albert Einstein, Louis de Broglie, David Bohm, Richard Feynman and others have spent years of their professional lives attempting to find resolution to the quantum mechanics predicament, with not much success. A shift of the quantum mechanics paradigm toward a deeper physics theory is long overdue.

Mechanism of crack healing at room temperature revealed by atomistic simulations

International Nuclear Information System (INIS)

Li, J.; Fang, Q.H.; Liu, B.; Liu, Y.; Liu, Y.W.; Wen, P.H.

2015-01-01

Three dimensional molecular dynamics (MD) simulations are systematically carried out to reveal the mechanism of the crack healing at room temperature, in terms of the dislocation shielding and the atomic diffusion to control the crack closure, in a copper (Cu) plate suffering from a shear loading. The results show that the process of the crack healing is actualized through the dislocation emission at a crack tip accompanied with intrinsic stacking faults ribbon forming in the crack tip wake, the dislocation slipping in the matrix and the dislocation annihilation in the free surface. Dislocation included stress compressing the crack tip is examined from the MD simulations and the analytical models, and then the crack closes rapidly due to the assistance of the atomic diffusion induced by the thermal activation when the crack opening displacement is less than a threshold value. This phenomenon is very different from the previous results for the crack propagation under the external load applied because of the crack healing (advancing) largely dependent on the crystallographic orientations of crack and the directions of external loading. Furthermore, based on the energy characteristic and considering the crack size effect, a theoretical model is established to predict the relationships between the crack size and the shear stress which qualitatively agree well with that obtained in the MD simulations

Revealing vilazodone's binding mechanism underlying its partial agonism to the 5-HT1A receptor in the treatment of major depressive disorder.

Science.gov (United States)

Zheng, Guoxun; Xue, Weiwei; Yang, Fengyuan; Zhang, Yang; Chen, Yuzong; Yao, Xiaojun; Zhu, Feng

2017-11-01

It has been estimated that major depressive disorder (MDD) will become the second largest global burden among all diseases by 2030. Various types of drugs, including selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and serotonin receptor partial agonist/reuptake inhibitors (SPARIs), have been approved and become the primary or first-line medications prescribed for MDD. SPARI was expected to demonstrate more enhanced drug efficacy and a rapid onset of action as compared to SSRI and SNRI. As one of the most famous SPARIs, vilazodone was approved by the FDA for the treatment of MDD. Because of the great clinical importance of vilazodone, its binding mechanism underlying its partial agonism to the 5-HT 1A receptor (5-HT 1A R) could provide valuable information to SPARIs' drug-like properties. However, this mechanism has not been reported to date; consequently, the rational design of new efficacious SPARI-based MDD drugs is severely hampered. To explore the molecular mechanism of vilazodone, an integrated computational strategy was adopted in this study to reveal its binding mechanism and prospective structural feature at the agonist binding site of 5-HT 1A R. As a result, 22 residues of this receptor were identified as hotspots, consistently favoring the binding of vilazodone and its analogues, and a common binding mechanism underlying their partial agonism to 5-HT 1A R was, therefore, discovered. Moreover, three main interaction features between vilazodone and 5-HT 1A R have been revealed and schematically summarized. In summary, this newly identified binding mechanism will provide valuable information for medicinal chemists working in the field of rational design of novel SPARIs for MDD treatment.

33 CFR 86.03 - Limits of fundamental frequencies.

Science.gov (United States)

2010-07-01

... of fundamental frequencies. To ensure a wide variety of whistle characteristics, the fundamental... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Limits of fundamental frequencies. 86.03 Section 86.03 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY...

Structure reveals regulatory mechanisms of a MaoC-like hydratase from Phytophthora capsici involved in biosynthesis of polyhydroxyalkanoates (PHAs.

Directory of Open Access Journals (Sweden)

Huizheng Wang

Full Text Available Polyhydroxyalkanoates (PHAs have attracted increasing attention as "green plastic" due to their biodegradable, biocompatible, thermoplastic, and mechanical properties, and considerable research has been undertaken to develop low cost/high efficiency processes for the production of PHAs. MaoC-like hydratase (MaoC, which belongs to (R-hydratase involved in linking the β-oxidation and the PHA biosynthetic pathways, has been identified recently. Understanding the regulatory mechanisms of (R-hydratase catalysis is critical for efficient production of PHAs that promise synthesis an environment-friendly plastic.We have determined the crystal structure of a new MaoC recognized from Phytophthora capsici. The crystal structure of the enzyme was solved at 2.00 Å resolution. The structure shows that MaoC has a canonical (R-hydratase fold with an N-domain and a C-domain. Supporting its dimerization observed in structure, MaoC forms a stable homodimer in solution. Mutations that disrupt the dimeric MaoC result in a complete loss of activity toward crotonyl-CoA, indicating that dimerization is required for the enzymatic activity of MaoC. Importantly, structure comparison reveals that a loop unique to MaoC interacts with an α-helix that harbors the catalytic residues of MaoC. Deletion of the loop enhances the enzymatic activity of MaoC, suggesting its inhibitory role in regulating the activity of MaoC.The data in our study reveal the regulatory mechanism of an (R-hydratase, providing information on enzyme engineering to produce low cost PHAs.

Fundamentals of reactor chemistry

International Nuclear Information System (INIS)

Akatsu, Eiko

1981-12-01

In the Nuclear Engineering School of JAERI, many courses are presented for the people working in and around the nuclear reactors. The curricula of the courses contain also the subject material of chemistry. With reference to the foreign curricula, a plan of educational subject material of chemistry in the Nuclear Engineering School of JAERI was considered, and the fundamental part of reactor chemistry was reviewed in this report. Since the students of the Nuclear Engineering School are not chemists, the knowledge necessary in and around the nuclear reactors was emphasized in order to familiarize the students with the reactor chemistry. The teaching experience of the fundamentals of reactor chemistry is also given. (author)

Fundamentals of electro-engineering I

International Nuclear Information System (INIS)

Rapsik, M.; Smola, M.; Bohac, M.; Mucha, M.

2004-01-01

This is the text-book of the fundamentals of electro-engineering. It contains the following chapters: (1) Selected terms in electro-engineering; (2) Fundamental electric values; (3) Energy and their transformations; (4) Water, hydro-energy and hydro-energetic potential of the Slovak Republic; (5) Nuclear power engineering; (6) Conventional thermal power plants; (7) Heating and cogeneration of electric power and heat production; (8) Equipment of electricity supply system; (9) Measurements in electro-engineering ; (10) Regulation of frequency and voltage, electric power quality

Value of Fundamental Science

Science.gov (United States)

Burov, Alexey

Fundamental science is a hard, long-term human adventure that has required high devotion and social support, especially significant in our epoch of Mega-science. The measure of this devotion and this support expresses the real value of the fundamental science in public opinion. Why does fundamental science have value? What determines its strength and what endangers it? The dominant answer is that the value of science arises out of curiosity and is supported by the technological progress. Is this really a good, astute answer? When trying to attract public support, we talk about the ``mystery of the universe''. Why do these words sound so attractive? What is implied by and what is incompatible with them? More than two centuries ago, Immanuel Kant asserted an inseparable entanglement between ethics and metaphysics. Thus, we may ask: which metaphysics supports the value of scientific cognition, and which does not? Should we continue to neglect the dependence of value of pure science on metaphysics? If not, how can this issue be addressed in the public outreach? Is the public alienated by one or another message coming from the face of science? What does it mean to be politically correct in this sort of discussion?

Atomic force microscopy stiffness tomography on living Arabidopsis thaliana cells reveals the mechanical properties of surface and deep cell-wall layers during growth.

Science.gov (United States)

Radotić, Ksenija; Roduit, Charles; Simonović, Jasna; Hornitschek, Patricia; Fankhauser, Christian; Mutavdžić, Dragosav; Steinbach, Gabor; Dietler, Giovanni; Kasas, Sandor

2012-08-08

Cell-wall mechanical properties play a key role in the growth and the protection of plants. However, little is known about genuine wall mechanical properties and their growth-related dynamics at subcellular resolution and in living cells. Here, we used atomic force microscopy (AFM) stiffness tomography to explore stiffness distribution in the cell wall of suspension-cultured Arabidopsis thaliana as a model of primary, growing cell wall. For the first time that we know of, this new imaging technique was performed on living single cells of a higher plant, permitting monitoring of the stiffness distribution in cell-wall layers as a function of the depth and its evolution during the different growth phases. The mechanical measurements were correlated with changes in the composition of the cell wall, which were revealed by Fourier-transform infrared (FTIR) spectroscopy. In the beginning and end of cell growth, the average stiffness of the cell wall was low and the wall was mechanically homogenous, whereas in the exponential growth phase, the average wall stiffness increased, with increasing heterogeneity. In this phase, the difference between the superficial and deep wall stiffness was highest. FTIR spectra revealed a relative increase in the polysaccharide/lignin content. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Some fundamental aspects of self-levitating sliding contact bearings and their practical implementations

OpenAIRE

Atherton, MA; Mares, C; Stolarski, TA

2014-01-01

In this study, fundamental aspects and mechanisms of acoustic levitation together with governing equations are presented first. Then, the acoustic levitation phenomenon is considered as a new way to design air suspension systems capable of self-levitation. A particular emphasis is laid on journal bearings and their specific geometrical configuration. A practical feasibility of using acoustic levitation to separate contacting surfaces is supported and illustrated by results of experimental tes...

Introduction and fundamentals

International Nuclear Information System (INIS)

Thomas, R.H.

1980-01-01

This introduction discusses advances in the fundamental sciences which underlie the applied science of health physics and radiation protection. Risk assessments in nuclear medicine are made by defining the conditions of exposure, identification of adverse effects, relating exposure with effect, and estimation of the overall risk for ionizing radiations

Fundamentals of astrodynamics

NARCIS (Netherlands)

Wakker, K.F.

2015-01-01

This book deals with the motion of the center of mass of a spacecraft; this discipline is generally called astrodynamics. The book focuses on an analytical treatment of the motion of spacecraft and provides insight into the fundamentals of spacecraft orbit dynamics. A large number of topics are

A fundamental study of fission product deposition on the wall surface

International Nuclear Information System (INIS)

Ishiguro, R.; Sakashita, H.; Sugiyama, K.

1987-01-01

Deposition of soluble matters on wall surfaces is studied in the present report for the purpose to understand a mechanism of fission product deposition on the wall surface in a molten salt reactor. Calcium carbonate solution is used to observe the fundamental mechanism of deposition. The experiments are performed under conditions of turbulent flow of the solution over a heated wall. According to the experimental results a model is proposed to estimate deposition rate. The model consists of two parts, one is the initial nucleus formation on a clean wall surface and the other is the constant increase of deposition succeeding to the first stage. The model is assessed by comparing it with the experimental results. Both results coincide well in some parameters, but not so well in others. (author)

Azadirachtin(A) distinctively modulates subdomain 2 of actin - novel mechanism to induce depolymerization revealed by molecular dynamics study.

Science.gov (United States)

Pravin Kumar, R; Roopa, L; Sudheer Mohammed, M M; Kulkarni, Naveen

2016-12-01

Azadirachtin(A) (AZA), a potential insecticide from neem, binds to actin and induces depolymerization in Drosophila. AZA binds to the pocket same as that of Latrunculin A (LAT), but LAT inhibits actin polymerization by stiffening the actin structure and affects the ADP-ATP exchange. The mechanism by which AZA induces actin depolymerization is not clearly understood. Therefore, different computational experiments were conducted to delineate the precise mechanism of AZA-induced actin depolymerization. Molecular dynamics studies showed that AZA strongly interacted with subdomain 2 and destabilized the interactions between subdomain 2 of one actin and subdomains 1 and 4 of the adjacent actin, causing the separation of actin subunits. The separation was observed between subdomain 3 of subunit n and subdomain 4 of subunit n + 2. However, the specific triggering point for the separation of the subunits was the destabilization of direct interactions between subdomain 2 of subunit n (Arg39, Val45, Gly46 and Arg62) and subdomain 4 of subunit n + 2 (Asp286, Ile287, Asp288, Ile289, Asp244 and Lys291). These results reveal a unique mechanism of an actin filament modulator that induces depolymerization. This mechanism of AZA can be used to design similar molecules against mammalian actins for cancer therapy.

Fundamental roles of reactive oxygen species and protective mechanisms in the female reproductive system

Directory of Open Access Journals (Sweden)

Okada Futoshi

2005-09-01

Full Text Available Abstract Controlled oxidation, such as disulfide bond formation in sperm nuclei and during ovulation, plays a fundamental role in mammalian reproduction. Excess oxidation, however, causes oxidative stress, resulting in the dysfunction of the reproductive process. Antioxidation reactions that reduce the levels of reactive oxygen species are of prime importance in reproductive systems in maintaining the quality of gametes and support reproduction. While anti-oxidative enzymes, such as superoxide dismutase and peroxidase, play a central role in eliminating oxidative stress, reduction-oxidation (redox systems, comprised of mainly glutathione and thioredoxin, function to reduce the levels of oxidized molecules. Aldo-keto reductase, using NADPH as an electron donor, detoxifies carbonyl compounds resulting from the oxidation of lipids and proteins. Thus, many antioxidative and redox enzyme genes are expressed and aggressively protect gametes and embryos in reproductive systems.

Statistical mechanics in JINR

International Nuclear Information System (INIS)

Tonchev, N.; Shumovskij, A.S.

1986-01-01

The history of investigations, conducted at the JINR in the field of statistical mechanics, beginning with the fundamental works by Bogolyubov N.N. on superconductivity microscopic theory is presented. Ideas, introduced in these works and methods developed in them, have largely determined the ways for developing statistical mechanics in the JINR and Hartree-Fock-Bogolyubov variational principle has become an important method of the modern nucleus theory. A brief review of the main achievements, connected with the development of statistical mechanics methods and their application in different fields of physical science is given

Recombination rate plasticity: revealing mechanisms by design

Science.gov (United States)

Sefick, Stephen; Rushton, Chase

2017-01-01

For over a century, scientists have known that meiotic recombination rates can vary considerably among individuals, and that environmental conditions can modify recombination rates relative to the background. A variety of external and intrinsic factors such as temperature, age, sex and starvation can elicit ‘plastic’ responses in recombination rate. The influence of recombination rate plasticity on genetic diversity of the next generation has interesting and important implications for how populations evolve. Further, many questions remain regarding the mechanisms and molecular processes that contribute to recombination rate plasticity. Here, we review 100 years of experimental work on recombination rate plasticity conducted in Drosophila melanogaster. We categorize this work into four major classes of experimental designs, which we describe via classic studies in D. melanogaster. Based on these studies, we highlight molecular mechanisms that are supported by experimental results and relate these findings to studies in other systems. We synthesize lessons learned from this model system into experimental guidelines for using recent advances in genotyping technologies, to study recombination rate plasticity in non-model organisms. Specifically, we recommend (1) using fine-scale genome-wide markers, (2) collecting time-course data, (3) including crossover distribution measurements, and (4) using mixed effects models to analyse results. To illustrate this approach, we present an application adhering to these guidelines from empirical work we conducted in Drosophila pseudoobscura. This article is part of the themed issue ‘Evolutionary causes and consequences of recombination rate variation in sexual organisms’. PMID:29109222

Failing to learn from negative prediction errors: Obesity is associated with alterations in a fundamental neural learning mechanism.

Science.gov (United States)

Mathar, David; Neumann, Jane; Villringer, Arno; Horstmann, Annette

2017-10-01

Prediction errors (PEs) encode the difference between expected and actual action outcomes in the brain via dopaminergic modulation. Integration of these learning signals ensures efficient behavioral adaptation. Obesity has recently been linked to altered dopaminergic fronto-striatal circuits, thus implying impairments in cognitive domains that rely on its integrity. 28 obese and 30 lean human participants performed an implicit stimulus-response learning paradigm inside an fMRI scanner. Computational modeling and psycho-physiological interaction (PPI) analysis was utilized for assessing PE-related learning and associated functional connectivity. We show that human obesity is associated with insufficient incorporation of negative PEs into behavioral adaptation even in a non-food context, suggesting differences in a fundamental neural learning mechanism. Obese subjects were less efficient in using negative PEs to improve implicit learning performance, despite proper coding of PEs in striatum. We further observed lower functional coupling between ventral striatum and supplementary motor area in obese subjects subsequent to negative PEs. Importantly, strength of functional coupling predicted task performance and negative PE utilization. These findings show that obesity is linked to insufficient behavioral adaptation specifically in response to negative PEs, and to associated alterations in function and connectivity within the fronto-striatal system. Recognition of neural differences as a central characteristic of obesity hopefully paves the way to rethink established intervention strategies: Differential behavioral sensitivity to negative and positive PEs should be considered when designing intervention programs. Measures relying on penalization of unwanted behavior may prove less effective in obese subjects than alternative approaches. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fundamentals of multicore software development

CERN Document Server

Pankratius, Victor; Tichy, Walter F

2011-01-01

With multicore processors now in every computer, server, and embedded device, the need for cost-effective, reliable parallel software has never been greater. By explaining key aspects of multicore programming, Fundamentals of Multicore Software Development helps software engineers understand parallel programming and master the multicore challenge. Accessible to newcomers to the field, the book captures the state of the art of multicore programming in computer science. It covers the fundamentals of multicore hardware, parallel design patterns, and parallel programming in C++, .NET, and Java. It

The fundamental interactions of matter

International Nuclear Information System (INIS)

Falla, D.F.

1977-01-01

Elementary particles are here discussed, in the context of the extent to which the fundamental interactions are related to the elementary constituents of matter. The field quanta related to the four fundamental interactions (electromagnetic, strong,weak and gravitational) are discussed within an historical context beginning with the conception of the photon. The discovery of the mesons and discoveries relevant to the nature of the heavy vector boson are considered. Finally a few recent speculations on the properties of the graviton are examined. (U.K.)

Deformation mechanisms in ferritic/martensitic steels and the impact on mechanical design

International Nuclear Information System (INIS)

Ghoniem, Nasr M.; Po, Giacomo; Sharafat, Shahram

2013-01-01

Structural steels for nuclear applications have undergone rapid development during the past few decades, thanks to a combination of trial-and-error, mechanism-based optimization, and multiscale modeling approaches. Deformation mechanisms are shown to be intimately related to mechanical design via dominant plastic deformation modes. Because mechanical design rules are mostly based on failure modes associated with plastic strain damage accumulation, we present here the fundamental deformation mechanisms for Ferritic/Martensitic (F/M) steels, and delineate their operational range of temperature and stress. The connection between deformation mechanisms, failure modes, and mechanical design is shown through application of design rules. A specific example is given for the alloy F82H utilized in the design of a Test Blanket Module (TBM) in the International Thermonuclear Experimental Reactor (ITER), where several constitutive equations are developed for design-related mechanical properties

Deformation mechanisms in ferritic/martensitic steels and the impact on mechanical design

Energy Technology Data Exchange (ETDEWEB)

Ghoniem, Nasr M., E-mail: ghoniem@seas.ucla.edu; Po, Giacomo; Sharafat, Shahram

2013-10-15

Structural steels for nuclear applications have undergone rapid development during the past few decades, thanks to a combination of trial-and-error, mechanism-based optimization, and multiscale modeling approaches. Deformation mechanisms are shown to be intimately related to mechanical design via dominant plastic deformation modes. Because mechanical design rules are mostly based on failure modes associated with plastic strain damage accumulation, we present here the fundamental deformation mechanisms for Ferritic/Martensitic (F/M) steels, and delineate their operational range of temperature and stress. The connection between deformation mechanisms, failure modes, and mechanical design is shown through application of design rules. A specific example is given for the alloy F82H utilized in the design of a Test Blanket Module (TBM) in the International Thermonuclear Experimental Reactor (ITER), where several constitutive equations are developed for design-related mechanical properties.

Quantum mechanics principles and formalism

CERN Document Server

McWeeny, Roy

2012-01-01

Focusing on main principles of quantum mechanics and their immediate consequences, this graduate student-oriented volume develops the subject as a fundamental discipline, opening with review of origins of Schrödinger's equations and vector spaces.

Fundamentals of time-dependent density functional theory

International Nuclear Information System (INIS)

Marques, Miguel A.L.; Rubio, Angel

2012-01-01

There have been many significant advances in time-dependent density functional theory over recent years, both in enlightening the fundamental theoretical basis of the theory, as well as in computational algorithms and applications. This book, as successor to the highly successful volume Time-Dependent Density Functional Theory (Lect. Notes Phys. 706, 2006) brings together for the first time all recent developments in a systematic and coherent way. First, a thorough pedagogical presentation of the fundamental theory is given, clarifying aspects of the original proofs and theorems, as well as presenting fresh developments that extend the theory into new realms such as alternative proofs of the original Runge-Gross theorem, open quantum systems, and dispersion forces to name but a few. Next, all of the basic concepts are introduced sequentially and building in complexity, eventually reaching the level of open problems of interest. Contemporary applications of the theory are discussed, from real-time coupled-electron-ion dynamics, to excited-state dynamics and molecular transport. Last but not least, the authors introduce and review recent advances in computational implementation, including massively parallel architectures and graphical processing units. Special care has been taken in editing this volume as a multi-author textbook, following a coherent line of thought, and making all the relevant connections between chapters and concepts consistent throughout. As such it will prove to be the text of reference in this field, both for beginners as well as expert researchers and lecturers teaching advanced quantum mechanical methods to model complex physical systems, from molecules to nanostructures, from biocomplexes to surfaces, solids and liquids. (orig.)

Functioning Mechanism of AlF ₃ Coating on the Li- and Mn-Rich Cathode Materials

Energy Technology Data Exchange (ETDEWEB)

Zheng, Jianming; Gu, Meng; Xiao, Jie; Polzin, Bryant J.; Yan, Pengfei; Chen, Xilin; Wang, Chongmin; Zhang, Ji-Guang

2014-11-25

We report systematic studies of the microstructural changes of uncoated and AlF3-coated Li-rich Mn-rich (LMR) cathode materials (Li1.2Ni0.15Co0.10Mn0.55O2) before and after cycling using a combination of aberration-corrected scanning/transmission electron microscopy (S/TEM) and electron energy loss spectroscopy (EELS). TEM coupled with EELS provides detailed information about the crystallographic and electronic structure changes that occur after cycling, thus revealing the fundamental improvement mechanism of surface coating. The results demonstrate that the surface coating reduces oxidation of the electrolyte at high voltage, suppressing the accumulation of a thick solid electrolyte interface (SEI) layer on electrode particle surface. Surface coating significantly enhances the stability of the surface structure and protects the electrode from severe etching/corrosion by the acidic species in the electrolyte, reducing the formation of etched surfaces and corrosion pits. Moreover, surface coating alleviates the undesirable voltage fade by mitigating layered to spinel-like phase transformation in the bulk region of the material. These fundamental findings may also be widely applied to explain the functioning mechanisms of other surface coatings used in a broad range of electrode materials.

O DIREITO FUNDAMENTAL AO DESENVOLVIMENTO SUSTENTÁVEL

OpenAIRE

Fernandes, Jeferson Nogueira

2012-01-01

Este artigo jurídico trata do direito fundamental do ser humano ter um desenvolvimento sustentável, e tem como objetivo identificar o desenvolvimento sustentável como sendo um direito fundamental consagrado universalmente. Em sua elaboração foi utilizado o seguinte material: textos doutrinários, legislação nacional pertinente e documentos internacionais. A conclusão indica que: o desenvolvimento sustentável é um direito fundamental do homem e que devemos manter equilibrada a relação ambiente ...

The Higgs mechanism and the origin of mass

Science.gov (United States)

Djouadi, Abdelhak

2012-06-01

The Higgs mechanism plays a key role in the physics of elementary particles: in the context of the Standard Model, the theory which describes in a unified framework the electromagnetic, weak and strong nuclear interactions, it allows for the generation of particle masses while preserving the fundamental symmetries of the theory. This mechanism predicts the existence of a new type of particle, the scalar Higgs boson, with unique characteristics. The detection of this particle and the study of its fundamental properties is a major goal of high-energy particle colliders, such as the CERN Large Hadron Collider or LHC.

RFID design fundamentals and applications

CERN Document Server

Lozano-Nieto, Albert

2010-01-01

RFID is an increasingly pervasive tool that is now used in a wide range of fields. It is employed to substantiate adherence to food preservation and safety standards, combat the circulation of counterfeit pharmaceuticals, and verify authenticity and history of critical parts used in aircraft and other machinery-and these are just a few of its uses. Goes beyond deployment, focusing on exactly how RFID actually worksRFID Design Fundamentals and Applications systematically explores the fundamental principles involved in the design and characterization of RFID technologies. The RFID market is expl

Astrophysical probes of fundamental physics

International Nuclear Information System (INIS)

Martins, C.J.A.P.

2009-01-01

I review the motivation for varying fundamental couplings and discuss how these measurements can be used to constrain fundamental physics scenarios that would otherwise be inaccessible to experiment. I highlight the current controversial evidence for varying couplings and present some new results. Finally I focus on the relation between varying couplings and dark energy, and explain how varying coupling measurements might be used to probe the nature of dark energy, with some advantages over standard methods. In particular I discuss what can be achieved with future spectrographs such as ESPRESSO and CODEX.

Astrophysical probes of fundamental physics

Energy Technology Data Exchange (ETDEWEB)

Martins, C.J.A.P. [Centro de Astrofisica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); DAMTP, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

2009-10-15

I review the motivation for varying fundamental couplings and discuss how these measurements can be used to constrain fundamental physics scenarios that would otherwise be inaccessible to experiment. I highlight the current controversial evidence for varying couplings and present some new results. Finally I focus on the relation between varying couplings and dark energy, and explain how varying coupling measurements might be used to probe the nature of dark energy, with some advantages over standard methods. In particular I discuss what can be achieved with future spectrographs such as ESPRESSO and CODEX.

Age and gender differences in fundamental motor skills (original version in English

Directory of Open Access Journals (Sweden)

Judith Jiménez Díaz

2015-10-01

Full Text Available Fundamental motor skills are the basis for participation in more advanced lifetime activities. Whereas considerable research has been reported on motor behavior of children, much less is known about performance in later years, especially adulthood. Therefore, the aim of this study was to examine age and gender differences on fundamental motor skills (FMS ability across three age groups: children (M = 9.37 yr., SD = 1.26, adolescents (M = 14.80 yr., SD = 2.04 and young-adults (M = 19.88 yr., SD = 2.72. Participants (n = 114 were assessed on five locomotor skills (run, gallop, slide, hop, and distance jump and five object control skills (bounce, catch, overhand throw, strike and kick using the Test for Fundamental Motor Skills, which is a process-oriented instrument. ANOVA results comparing gender and group revealed no significant interactions. Moreover, main effects for group were found for three individual skills: galloping –adolescents and young-adults performed better than children (p < .01–, throwing –children and adolescents performed better than young-adults (p < .01 –, and kicking –young-adults performed better than children and adolescents (p < .05–. Also, we found main effects for gender for total FMS ability (p < .01, locomotor subscale (p < .05 and object control subscale (p < .01, and for six individual motor skills: run (p < .05, jump (p < .05, throw (p < .01, kick (p < .01, bounce (p < .01 and strike (p < .01; males outperformed females for all the skills. However, in view of total FMS ability, locomotor skills and object control skills results suggest similar performance across ages. Therefore, it is important to enhance fundamental motor skills at all ages, as an option to help individuals engage in physical activities.

Android Emotions Revealed

DEFF Research Database (Denmark)

Vlachos, Evgenios; Schärfe, Henrik

2012-01-01

This work presents a method for designing facial interfaces for sociable android robots with respect to the fundamental rules of human affect expression. Extending the work of Paul Ekman towards a robotic direction, we follow the judgment-based approach for evaluating facial expressions to test...... findings are based on the results derived from a number of judgments, and suggest that before programming the facial expressions of a Geminoid, the Original should pass through the proposed procedure. According to our recommendations, the facial expressions of an android should be tested by judges, even...... in which case an android robot like the Geminoid|DK –a duplicate of an Original person- reveals emotions convincingly; when following an empirical perspective, or when following a theoretical one. The methodology includes the processes of acquiring the empirical data, and gathering feedback on them. Our...

Shareholders' Fundamental Rights in Listed Companies

DEFF Research Database (Denmark)

Werlauff, Erik

2017-01-01

There can be no reasonable doubt that the EU’s initiatives in the field of shareholders’ fundamental rights in listed companies are among the successful, relevant and necessary provisions under EU corporate and stock exchange law. This also holds true for the main Directive 2007/36. When consider......There can be no reasonable doubt that the EU’s initiatives in the field of shareholders’ fundamental rights in listed companies are among the successful, relevant and necessary provisions under EU corporate and stock exchange law. This also holds true for the main Directive 2007/36. When...... considering the whole spirit and idea of the EU and its competences, the field of basic shareholders’ rights, including cross-border shareholding, is to be regarded as a welcome initiative that has facilitated the exercise of fundamental rights also in cross-border shareholding. The success is further...... emphasized by the fact that some countries, including Denmark, have regarded a number of the fundamental rights vested in the directive as being so well formulated that the countries have chosen to gold-plate their own legislation by introducing rights which are similar to those in the directive also for non...

Default Bayesian Estimation of the Fundamental Frequency

DEFF Research Database (Denmark)

Nielsen, Jesper Kjær; Christensen, Mads Græsbøll; Jensen, Søren Holdt

2013-01-01

Joint fundamental frequency and model order esti- mation is an important problem in several applications. In this paper, a default estimation algorithm based on a minimum of prior information is presented. The algorithm is developed in a Bayesian framework, and it can be applied to both real....... Moreover, several approximations of the posterior distributions on the fundamental frequency and the model order are derived, and one of the state-of-the-art joint fundamental frequency and model order estimators is demonstrated to be a special case of one of these approximations. The performance...

Numerical analysis of effects of transglottal pressure change on fundamental frequency of phonation.

Science.gov (United States)

Deguchi, Shinji; Matsuzaki, Yuji; Ikeda, Tadashige

2007-02-01

In humans, a decrease in transglottal pressure (Pt) causes an increase in the fundamental frequency of phonation (F0) only at a specific voice pitch within the modal register, the mechanism of which remains unclear. In the present study, numerical analyses were performed to investigate the mechanism of the voice pitch-dependent positive change of F0 due to Pt decrease. The airflow and the airway, including the vocal folds, were modeled in terms of mechanics of fluid and structure. Simulations of phonation using the numerical model indicated that Pt affects both the average position and the average amplitude magnitude of vocal fold self-excited oscillation in a non-monotonous manner. This effect results in voice pitch-dependent responses of F0 to Pt decreases, including the positive response of F0 as actually observed in humans. The findings of the present study highlight the importance of considering self-excited oscillation of the vocal folds in elucidation of the phonation mechanism.

Fundamental limit of nanophotonic light trapping in solar cells.

Science.gov (United States)

Yu, Zongfu; Raman, Aaswath; Fan, Shanhui

2010-10-12

Establishing the fundamental limit of nanophotonic light-trapping schemes is of paramount importance and is becoming increasingly urgent for current solar cell research. The standard theory of light trapping demonstrated that absorption enhancement in a medium cannot exceed a factor of 4n(2)/sin(2)θ, where n is the refractive index of the active layer, and θ is the angle of the emission cone in the medium surrounding the cell. This theory, however, is not applicable in the nanophotonic regime. Here we develop a statistical temporal coupled-mode theory of light trapping based on a rigorous electromagnetic approach. Our theory reveals that the conventional limit can be substantially surpassed when optical modes exhibit deep-subwavelength-scale field confinement, opening new avenues for highly efficient next-generation solar cells.

Mechanical engineering science in SI units

CERN Document Server

Gwyther, J L; Williams, G

1970-01-01

0.1 Mechanical Engineering Science covers various fundamental concepts that are essential in the practice of mechanical engineering. The title is comprised of 19 chapters that detail various topics, including chemical and physical laws. The coverage of the book includes Newtonian laws, mechanical energy, friction, stress, and gravity. The text also discusses the chemical aspects of mechanical engineering, which include gas laws, states of matter, and fuel combustion. The last chapter tackles concerns in laboratory experiments. The book will be of great use to students of mechanical eng

Patterned biofilm formation reveals a mechanism for structural heterogeneity in bacterial biofilms.

Science.gov (United States)

Gu, Huan; Hou, Shuyu; Yongyat, Chanokpon; De Tore, Suzanne; Ren, Dacheng

2013-09-03

Bacterial biofilms are ubiquitous and are the major cause of chronic infections in humans and persistent biofouling in industry. Despite the significance of bacterial biofilms, the mechanism of biofilm formation and associated drug tolerance is still not fully understood. A major challenge in biofilm research is the intrinsic heterogeneity in the biofilm structure, which leads to temporal and spatial variation in cell density and gene expression. To understand and control such structural heterogeneity, surfaces with patterned functional alkanthiols were used in this study to obtain Escherichia coli cell clusters with systematically varied cluster size and distance between clusters. The results from quantitative imaging analysis revealed an interesting phenomenon in which multicellular connections can be formed between cell clusters depending on the size of interacting clusters and the distance between them. In addition, significant differences in patterned biofilm formation were observed between wild-type E. coli RP437 and some of its isogenic mutants, indicating that certain cellular and genetic factors are involved in interactions among cell clusters. In particular, autoinducer-2-mediated quorum sensing was found to be important. Collectively, these results provide missing information that links cell-to-cell signaling and interaction among cell clusters to the structural organization of bacterial biofilms.

Friction Force: From Mechanics to Thermodynamics

Science.gov (United States)

Ferrari, Christian; Gruber, Christian

2010-01-01

We study some mechanical problems in which a friction force is acting on a system. Using the fundamental concepts of state, time evolution and energy conservation, we explain how to extend Newtonian mechanics to thermodynamics. We arrive at the two laws of thermodynamics and then apply them to investigate the time evolution and heat transfer of…

Mechanism of unconventional aerodynamic characteristics of an elliptic airfoil

Directory of Open Access Journals (Sweden)

Sun Wei

2015-06-01

Full Text Available The aerodynamic characteristics of elliptic airfoil are quite different from the case of conventional airfoil for Reynolds number varying from about 104 to 106. In order to reveal the fundamental mechanism, the unsteady flow around a stationary two-dimensional elliptic airfoil with 16% relative thickness has been simulated using unsteady Reynolds-averaged Navier–Stokes equations and the γ-Reθt‾ transition turbulence model at different angles of attack for flow Reynolds number of 5 × 105. The aerodynamic coefficients and the pressure distribution obtained by computation are in good agreement with experimental data, which indicates that the numerical method works well. Through this study, the mechanism of the unconventional aerodynamic characteristics of airfoil is analyzed and discussed based on the computational predictions coupled with the wind tunnel results. It is considered that the boundary layer transition at the leading edge and the unsteady flow separation vortices at the trailing edge are the causes of the case. Furthermore, a valuable insight into the physics of how the flow behavior affects the elliptic airfoil’s aerodynamics is provided.

Crossdisciplinary fundamental research--the seed for scientific advance and technological innovation.

Science.gov (United States)

Kroto, Harold

2011-12-28

As it was earlier in the 1980's, so it is now, fundamental science research is under threat as decisions are made on science funding by people who do not do fundamental research, seem congenitally incapable of understanding what it is and furthermore in the face of countless examples seem blind to how important it has been to the technologies that govern our modern life and will be to the future technologies that we desperately need to develop to survive. In this article some general observations are made on how the fascination for what happens in space and stars was the key trigger that gave birth to Science itself and a particular case is outlined which indicates that this same fascination is still the catalyst of some fundamental breakthroughs today. This article also outlines an archetypal example of the way major breakthroughs are often made by the synergy that comes from cross-disciplinary research in a way which is totally surprising. In this case it started from a curiosity about the quantum mechanical description of molecular dynamics and involved pioneering advances in synthetic organic chemistry which led to the suprising discovery that some exotic carbon molecules were abundant in space and stars. These results initiated an experiment using a new technology that represented a major breakthrough in cluster science. The upshot was totally unpredictable, the birth of a whole new field of Chemistry as well as a paradigm shift in major areas of Nanoscience and Nanotechnology.

Unified composite model of all fundamental particles and forces

International Nuclear Information System (INIS)

Terazawa, H.

2000-01-01

The unified supersymmetric composite model of all fundamental particles (and forces) including not only the fundamental fermions (quarks and leptons) but also the fundamental bosons (gauge bosons and Higgs scalars) is reviewed in detail

Study of nozzle deposit formation mechanism for direct injection gasoline engines; Chokufun gasoline engine yo nozzle no deposit seisei kaiseki

Energy Technology Data Exchange (ETDEWEB)

Kinoshita, M; Saito, A [Toyota Central Research and Development Labs., Inc., Aichi (Japan); Matsushita, S [Toyota Motor Corp., Aichi (Japan); Shibata, H [Nippon Soken, Inc., Tokyo (Japan); Niwa, Y [Denso Corp., Aichi (Japan)

1997-10-01

Nozzles in fuel injectors for direct injection gasoline engines are exposed to high temperature combustion gases and soot. In such a rigorous environment, it is a fear that fuel flow rate changes in injectors by deposit formation on nozzles. Fundamental factors of nozzle deposit formation were investigated through injector bench tests and engine dynamometer tests. Deposit formation processes were observed by SEM through engine dynamometer tests. The investigation results reveal nozzle deposit formation mechanism and how to suppress the deposit. 4 refs., 8 figs., 3 tabs.

The Fundamental Principle of Human Dignity and the Right to Life : Collision Any of These Fundamental Principles The Perspective of Abortion

Directory of Open Access Journals (Sweden)

Érika do Amaral Véras

2016-12-01

Full Text Available This legal article works the theme of the collision of the fundamental principles, especially the principle of human dignity and the right to life, abortion perspective. First, we discuss of fundamental rights, bringing its definition, observed the distinction between human rights and fundamental rights. Then the super principle of human dignity is covered and, soon after, the right to life is highlighted through its relevant elements. Finally, talks on a possible collision beween the fundamental right to life and the principle of human dignity, with a special focus on the issue of abortion.

Talaromyces marneffei Genomic, Transcriptomic, Proteomic and Metabolomic Studies Reveal Mechanisms for Environmental Adaptations and Virulence

Directory of Open Access Journals (Sweden)

Susanna K. P. Lau

2017-06-01

Full Text Available Talaromyces marneffei is a thermally dimorphic fungus causing systemic infections in patients positive for HIV or other immunocompromised statuses. Analysis of its ~28.9 Mb draft genome and additional transcriptomic, proteomic and metabolomic studies revealed mechanisms for environmental adaptations and virulence. Meiotic genes and genes for pheromone receptors, enzymes which process pheromones, and proteins involved in pheromone response pathway are present, indicating its possibility as a heterothallic fungus. Among the 14 Mp1p homologs, only Mp1p is a virulence factor binding a variety of host proteins, fatty acids and lipids. There are 23 polyketide synthase genes, one for melanin and two for mitorubrinic acid/mitorubrinol biosynthesis, which are virulence factors. Another polyketide synthase is for biogenesis of the diffusible red pigment, which consists of amino acid conjugates of monascorubin and rubropunctatin. Novel microRNA-like RNAs (milRNAs and processing proteins are present. The dicer protein, dcl-2, is required for biogenesis of two milRNAs, PM-milR-M1 and PM-milR-M2, which are more highly expressed in hyphal cells. Comparative transcriptomics showed that tandem repeat-containing genes were overexpressed in yeast phase, generating protein polymorphism among cells, evading host’s immunity. Comparative proteomics between yeast and hyphal cells revealed that glyceraldehyde-3-phosphate dehydrogenase, up-regulated in hyphal cells, is an adhesion factor for conidial attachment.

48 CFR 9904.416-40 - Fundamental requirement.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Fundamental requirement..., OFFICE OF FEDERAL PROCUREMENT POLICY, OFFICE OF MANAGEMENT AND BUDGET PROCUREMENT PRACTICES AND COST ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS 9904.416-40 Fundamental requirement. (a) The amount of...

48 CFR 9904.413-40 - Fundamental requirement.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Fundamental requirement..., OFFICE OF FEDERAL PROCUREMENT POLICY, OFFICE OF MANAGEMENT AND BUDGET PROCUREMENT PRACTICES AND COST ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS 9904.413-40 Fundamental requirement. (a) Assignment of...

48 CFR 9904.417-40 - Fundamental requirement.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Fundamental requirement... ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS 9904.417-40 Fundamental requirement. The cost of money applicable to the investment in tangible and intangible capital assets being constructed, fabricated, or...

48 CFR 9905.501-40 - Fundamental requirement.

Science.gov (United States)

2010-10-01

... ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS FOR EDUCATIONAL INSTITUTIONS 9905.501-40 Fundamental... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Fundamental requirement. 9905.501-40 Section 9905.501-40 Federal Acquisition Regulations System COST ACCOUNTING STANDARDS BOARD...

48 CFR 9905.502-40 - Fundamental requirement.

Science.gov (United States)

2010-10-01

... ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS FOR EDUCATIONAL INSTITUTIONS 9905.502-40 Fundamental... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Fundamental requirement. 9905.502-40 Section 9905.502-40 Federal Acquisition Regulations System COST ACCOUNTING STANDARDS BOARD...

48 CFR 9905.506-40 - Fundamental requirement.

Science.gov (United States)

2010-10-01

... ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS FOR EDUCATIONAL INSTITUTIONS 9905.506-40 Fundamental... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Fundamental requirement. 9905.506-40 Section 9905.506-40 Federal Acquisition Regulations System COST ACCOUNTING STANDARDS BOARD...

Principles of physics from quantum field theory to classical mechanics

CERN Document Server

Jun, Ni

2014-01-01

This book starts from a set of common basic principles to establish the formalisms in all areas of fundamental physics, including quantum field theory, quantum mechanics, statistical mechanics, thermodynamics, general relativity, electromagnetic field, and classical mechanics. Instead of the traditional pedagogic way, the author arranges the subjects and formalisms in a logical-sequential way, i.e. all the formulas are derived from the formulas before them. The formalisms are also kept self-contained. Most of the required mathematical tools are also given in the appendices. Although this book covers all the disciplines of fundamental physics, the book is concise and can be treated as an integrated entity. This is consistent with the aphorism that simplicity is beauty, unification is beauty, and thus physics is beauty. The book may be used as an advanced textbook by graduate students. It is also suitable for physicists who wish to have an overview of fundamental physics. Readership: This is an advanced gradua...

Fundamental uncertainty limit of optical flow velocimetry according to Heisenberg's uncertainty principle.

Science.gov (United States)

Fischer, Andreas

2016-11-01

Optical flow velocity measurements are important for understanding the complex behavior of flows. Although a huge variety of methods exist, they are either based on a Doppler or a time-of-flight measurement principle. Doppler velocimetry evaluates the velocity-dependent frequency shift of light scattered at a moving particle, whereas time-of-flight velocimetry evaluates the traveled distance of a scattering particle per time interval. Regarding the aim of achieving a minimal measurement uncertainty, it is unclear if one principle allows to achieve lower uncertainties or if both principles can achieve equal uncertainties. For this reason, the natural, fundamental uncertainty limit according to Heisenberg's uncertainty principle is derived for Doppler and time-of-flight measurement principles, respectively. The obtained limits of the velocity uncertainty are qualitatively identical showing, e.g., a direct proportionality for the absolute value of the velocity to the power of 32 and an indirect proportionality to the square root of the scattered light power. Hence, both measurement principles have identical potentials regarding the fundamental uncertainty limit due to the quantum mechanical behavior of photons. This fundamental limit can be attained (at least asymptotically) in reality either with Doppler or time-of-flight methods, because the respective Cramér-Rao bounds for dominating photon shot noise, which is modeled as white Poissonian noise, are identical with the conclusions from Heisenberg's uncertainty principle.

Fundamental limits to position determination by concentration gradients.

Directory of Open Access Journals (Sweden)

Filipe Tostevin

2007-04-01

Full Text Available Position determination in biological systems is often achieved through protein concentration gradients. Measuring the local concentration of such a protein with a spatially varying distribution allows the measurement of position within the system. For these systems to work effectively, position determination must be robust to noise. Here, we calculate fundamental limits to the precision of position determination by concentration gradients due to unavoidable biochemical noise perturbing the gradients. We focus on gradient proteins with first-order reaction kinetics. Systems of this type have been experimentally characterised in both developmental and cell biology settings. For a single gradient we show that, through time-averaging, great precision potentially can be achieved even with very low protein copy numbers. As a second example, we investigate the ability of a system with oppositely directed gradients to find its centre. With this mechanism, positional precision close to the centre improves more slowly with increasing averaging time, and so longer averaging times or higher copy numbers are required for high precision. For both single and double gradients, we demonstrate the existence of optimal length scales for the gradients for which precision is maximized, as well as analyze how precision depends on the size of the concentration-measuring apparatus. These results provide fundamental constraints on the positional precision supplied by concentration gradients in various contexts, including both in developmental biology and also within a single cell.

Fundamental understanding and rational design of high energy structural microbatteries

Energy Technology Data Exchange (ETDEWEB)

Wang, Yuxing; Li, Qiuyan; Cartmell, Samuel; Li, Huidong; Mendoza, Sarah; Zhang, Ji-Guang; Deng, Zhiqun Daniel; Xiao, Jie

2018-01-01

Microbatteries play a critical role in determining the lifetime of downsized sensors, wearable devices and medical applications, etc. More often, structural batteries are required from the perspective of aesthetics and space utilization, which is however rarely explored. Herein, we discuss the fundamental issues associated with the rational design of practically usable high energy microbatteries. The tubular shape of the cell further allows the flexible integration of microelectronics. A functioning acoustic micro-transmitter continuously powered by this tubular battery has been successfully demonstrated. Multiple design features adopted to accommodate large mechanical stress during the rolling process are discussed providing new insights in designing the structural microbatteries for emerging technologies.

A Kalman-based Fundamental Frequency Estimation Algorithm

DEFF Research Database (Denmark)

Shi, Liming; Nielsen, Jesper Kjær; Jensen, Jesper Rindom

2017-01-01

Fundamental frequency estimation is an important task in speech and audio analysis. Harmonic model-based methods typically have superior estimation accuracy. However, such methods usually as- sume that the fundamental frequency and amplitudes are station- ary over a short time frame. In this pape...

48 CFR 9904.420-40 - Fundamental requirement.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Fundamental requirement..., OFFICE OF FEDERAL PROCUREMENT POLICY, OFFICE OF MANAGEMENT AND BUDGET PROCUREMENT PRACTICES AND COST ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS 9904.420-40 Fundamental requirement. (a) The basic unit for...

48 CFR 9904.411-40 - Fundamental requirement.

Science.gov (United States)

2010-10-01

... ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS 9904.411-40 Fundamental requirement. (a) The contractor shall... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Fundamental requirement. 9904.411-40 Section 9904.411-40 Federal Acquisition Regulations System COST ACCOUNTING STANDARDS BOARD...

48 CFR 9904.402-40 - Fundamental requirement.

Science.gov (United States)

2010-10-01

... ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS 9904.402-40 Fundamental requirement. All costs incurred for... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Fundamental requirement. 9904.402-40 Section 9904.402-40 Federal Acquisition Regulations System COST ACCOUNTING STANDARDS BOARD...

48 CFR 9904.418-40 - Fundamental requirements.

Science.gov (United States)

2010-10-01

... ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS 9904.418-40 Fundamental requirements. (a) A business unit... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Fundamental requirements. 9904.418-40 Section 9904.418-40 Federal Acquisition Regulations System COST ACCOUNTING STANDARDS BOARD...

Genome editing reveals a role for OCT4 in human embryogenesis.

Science.gov (United States)

Fogarty, Norah M E; McCarthy, Afshan; Snijders, Kirsten E; Powell, Benjamin E; Kubikova, Nada; Blakeley, Paul; Lea, Rebecca; Elder, Kay; Wamaitha, Sissy E; Kim, Daesik; Maciulyte, Valdone; Kleinjung, Jens; Kim, Jin-Soo; Wells, Dagan; Vallier, Ludovic; Bertero, Alessandro; Turner, James M A; Niakan, Kathy K

2017-10-05

Despite their fundamental biological and clinical importance, the molecular mechanisms that regulate the first cell fate decisions in the human embryo are not well understood. Here we use CRISPR-Cas9-mediated genome editing to investigate the function of the pluripotency transcription factor OCT4 during human embryogenesis. We identified an efficient OCT4-targeting guide RNA using an inducible human embryonic stem cell-based system and microinjection of mouse zygotes. Using these refined methods, we efficiently and specifically targeted the gene encoding OCT4 (POU5F1) in diploid human zygotes and found that blastocyst development was compromised. Transcriptomics analysis revealed that, in POU5F1-null cells, gene expression was downregulated not only for extra-embryonic trophectoderm genes, such as CDX2, but also for regulators of the pluripotent epiblast, including NANOG. By contrast, Pou5f1-null mouse embryos maintained the expression of orthologous genes, and blastocyst development was established, but maintenance was compromised. We conclude that CRISPR-Cas9-mediated genome editing is a powerful method for investigating gene function in the context of human development.

Engineering quantum mechanics

CERN Document Server

Ahn, Doyeol

2011-01-01

A clear introduction to quantum mechanics concepts Quantum mechanics has become an essential tool for modern engineering, particularly due to the recent developments in quantum computing as well as the rapid progress in optoelectronic devices. Engineering Quantum Mechanics explains the fundamentals of this exciting field, providing broad coverage of both traditional areas such as semiconductor and laser physics as well as relatively new yet fast-growing areas such as quantum computation and quantum information technology. The book begins with basic quantum mechanics, reviewing measurements and probability, Dirac formulation, the uncertainty principle, harmonic oscillator, angular momentum eigenstates, and perturbation theory. Then, quantum statistical mechanics is explored, from second quantization and density operators to coherent and squeezed states, coherent interactions between atoms and fields, and the Jaynes-Cummings model. From there, the book moves into elementary and modern applications, discussing s...

Fundamentals of MALDI-ToF-MS analysis applications in bio-diagnosis, tissue engineering and drug delivery

CERN Document Server

Hosseini, Samira

2017-01-01

This book presents the fundamentals and applications of Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-ToF-MS) technique. It highlights the basic principles, the history of invention as well as the mechanism of ionization and mass determination using this technique. It describes the fundamental principles and methods for MALDI spectra interpretation and determination of exact chemical structures from experimental data. This book guides the reader through the interpretation of MALDI data where complex macromolecular spectra are simplified in order to present the major principles behind data interpretation. In addition, each chapter describes how MALDI-ToF-MS analysis provides necessary understanding of the copolymer systems that have been designed for specialized biomedical applications.

Fundamental frequency characteristics of Jordanian Arabic speakers.

Science.gov (United States)

Natour, Yaser S; Wingate, Judith M

2009-09-01

This study is the first in a series of investigations designed to test the acoustic characteristics of the normal Arabic voice. The subjects were three hundred normal Jordanian Arabic speakers (100 adult males, 100 adult females, and 100 children). The subjects produced a sustained phonation of the vowel /a:/ and stated their complete names (i.e. first, second, third and surname) using a carrier phrase. The samples were analyzed using the Multi Dimensional Voice Program (MDVP). Fundamental frequency (F0) from the /a:/ and speaking fundamental frequency (SF0) from the sentence were analyzed. Results revealed a significant difference of both F0 and SF0 values among adult Jordanian Arabic-speaking males (F0=131.34Hz +/- 18.65, SF0=137.45 +/- 18.93), females (F0=231.13Hz +/- 20.86, SF0=230.84 +/- 16.50) and children (F0=270.93Hz +/- 20.01, SF0=278.04 +/- 32.07). Comparison with other ethnicities indicated that F0 values of adult Jordanian Arabic-speaking males and females are generally consistent with adult Caucasian and African-American values. However, for Jordanian Arabic-speaking children, a higher trend in F0 values was present than their Western counterparts. SF0 values for adult Jordanian Arabic-speaking males are generally consistent with the adult Caucasian male SF0 values. However, SF0 values of adult Jordanian-speaking females and children were relatively higher than the reported Western values. It is recommended that speech-language pathologists in Arabic-speaking countries, Jordan in specific, utilize the new data provided (F0 and SF0) when evaluating and/or treating Arabic-speaking patients. Due to its cross-linguistic variability, SF0 emerged as a preferred measurement when conducting cross-cultural comparisons of voice features.

Atomic force microscopy: Unraveling the fundamental principles governing secretion and membrane fusion in cells

International Nuclear Information System (INIS)

Jena, Bhanu P.

2009-01-01

The story of cell secretion and membrane fusion is as old as life itself. Without these fundamental cellular processes known to occur in yeast to humans, life would cease to exist. In the last 15 years, primarily using the atomic force microscope, a detailed understanding of the molecular process and of the molecular machinery and mechanism of secretion and membrane fusion in cells has come to light. This has led to a paradigm shift in our understanding of the underlying mechanism of cell secretion. The journey leading to the discovery of a new cellular structure the 'porosome',-the universal secretory machinery in cells, and the contributions of the AFM in our understanding of the general molecular machinery and mechanism of cell secretion and membrane fusion, is briefly discussed in this article.

Overview of the fundamental safety principles

International Nuclear Information System (INIS)

Chishinga, Milton Mulenga

2015-02-01

The primary objective of this work was to provide an overview of the International Atomic Energy (IAEA) document; 'Fundamental Safety principles, SF.1'. The document outlines ten (10) fundamental principles which provide the basis for an effective the radiation protection framework. The document is the topmost in the hierarchy of the IAEA Safety Standards Series. These principles are the foundation of the nuclear safety put stringent obligations on Parties under the Convention on Nuclear Safety. The fundamental safety objective is to protect people and the environment from harmful effects of ionizing radiation. The fundamental Safety objective of protecting people individually and collectively and the environment has to be achieved without unduly limiting the operation of facilities or the conduct of activities that give rise to risks. The thematic areas covered are; responsibility for safety, role of government, leadership and management for safety, justification of facilities and activities, optimization of protection, limitation of risks to individuals, protection of present and future generations, prevention of accidents, emergency preparedness and response and protective actions to reduce existing or unregulated radiation risks. Appropriate recommendations have been provided for effective application of the principles by Governments, Regulatory Bodies and Operating Organizations of facilities and Nuclear Installations the give rise to radiation risks. (au)

Fundamentals of electrochemical science

CERN Document Server

Oldham, Keith

1993-01-01

Key Features* Deals comprehensively with the basic science of electrochemistry* Treats electrochemistry as a discipline in its own right and not as a branch of physical or analytical chemistry* Provides a thorough and quantitative description of electrochemical fundamentals

Modern mechanical engineering research, development and education

CERN Document Server

2014-01-01

This book covers modern subjects of mechanical engineering such as nanomechanics and nanotechnology, mechatronics and robotics, computational mechanics, biomechanics, alternative energies, sustainability as well as all aspects related with mechanical engineering education. The chapters help enhance the understanding of both the fundamentals of mechanical engineering and its application to the solution of problems in modern industry. This book is suitable for students, both in final undergraduate mechanical engineering courses or at the graduate level. It also serves as a useful reference for academics, mechanical engineering researchers, mechanical, materials and manufacturing engineers, professionals in related with mechanical engineering.

Safety analysis fundamentals

International Nuclear Information System (INIS)

Wright, A.C.D.

2002-01-01

This paper discusses the safety analysis fundamentals in reactor design. This study includes safety analysis done to show consequences of postulated accidents are acceptable. Safety analysis is also used to set design of special safety systems and includes design assist analysis to support conceptual design. safety analysis is necessary for licensing a reactor, to maintain an operating license, support changes in plant operations

Deciding where to attend: Large-scale network mechanisms underlying attention and intention revealed by graph-theoretic analysis.

Science.gov (United States)

Liu, Yuelu; Hong, Xiangfei; Bengson, Jesse J; Kelley, Todd A; Ding, Mingzhou; Mangun, George R

2017-08-15

The neural mechanisms by which intentions are transformed into actions remain poorly understood. We investigated the network mechanisms underlying spontaneous voluntary decisions about where to focus visual-spatial attention (willed attention). Graph-theoretic analysis of two independent datasets revealed that regions activated during willed attention form a set of functionally-distinct networks corresponding to the frontoparietal network, the cingulo-opercular network, and the dorsal attention network. Contrasting willed attention with instructed attention (where attention is directed by external cues), we observed that the dorsal anterior cingulate cortex was allied with the dorsal attention network in instructed attention, but shifted connectivity during willed attention to interact with the cingulo-opercular network, which then mediated communications between the frontoparietal network and the dorsal attention network. Behaviorally, greater connectivity in network hubs, including the dorsolateral prefrontal cortex, the dorsal anterior cingulate cortex, and the inferior parietal lobule, was associated with faster reaction times. These results, shown to be consistent across the two independent datasets, uncover the dynamic organization of functionally-distinct networks engaged to support intentional acts. Copyright © 2017 Elsevier Inc. All rights reserved.

Electron Transfer Reactivity Patterns at Chemically Modified Electrodes: Fundamentals and Application to the Optimization of Redox Recycling Amplification Systems

Energy Technology Data Exchange (ETDEWEB)

Bergren, Adam Johan [Iowa State Univ., Ames, IA (United States)

2006-01-01

Electroanalytical chemistry is often utilized in chemical analysis and Fundamental studies. Important advances have been made in these areas since the advent of chemically modified electrodes: the coating of an electrode with a chemical film in order to impart desirable, and ideally, predictable properties. These procedures enable the exploitation of unique reactivity patterns. This dissertation presents studies that investigate novel reaction mechanisms at self-assembled monolayers on gold. In particular, a unique electrochemical current amplification scheme is detailed that relies on a selective electrode to enable a reactivity pattern that results in regeneration of the analyte (redox recycling). This regenerating reaction can occur up to 250 times for each analyte molecule, leading to a notable enhancement in the observed current. The requirements of electrode selectivity and the resulting amplification and detection limit improvements are described with respect to the heterogeneous and homogeneous electron transfer rates that characterize the system. These studies revealed that the heterogeneous electrolysis of the analyte should ideally be electrochemically reversible, while that for the regenerating agent should be held to a low level. Moreover, the homogeneous reaction that recycles the analyte should occur at a rapid rate. The physical selectivity mechanism is also detailed with respect to the properties of the electrode and redox probes utilized. It is shown that partitioning of the analyte into/onto the adlayer leads to the extraordinary selectivity of the alkanethiolate monolayer modified electrode. Collectively, these studies enable a thorough understanding of the complex electrode mechanism required for successful redox recycling amplification systems, Finally, in a separate (but related) study, the effect of the akyl chain length on the heterogeneous electron transfer behavior of solution-based redox probes is reported, where an odd-even oscillation

Mechanics and thermodynamics

CERN Document Server

Demtröder, Wolfgang

2017-01-01

This introduction to classical mechanics and thermodynamics provides an accessible and clear treatment of the fundamentals. Starting with particle mechanics and an early introduction to special relativity this textbooks enables the reader to understand the basics in mechanics. The text is written from the experimental physics point of view, giving numerous real life examples and applications of classical mechanics in technology. This highly motivating presentation deepens the knowledge in a very accessible way. The second part of the text gives a concise introduction to rotational motion, an expansion to rigid bodies, fluids and gases. Finally, an extensive chapter on thermodynamics and a short introduction to nonlinear dynamics with some instructive examples intensify the knowledge of more advanced topics. Numerous problems with detailed solutions are perfect for self study.

Parametric study of control mechanism of cortical bone remodeling under mechanical stimulus

Science.gov (United States)

Wang, Yanan; Qin, Qing-Hua

2010-03-01

The control mechanism of mechanical bone remodeling at cellular level was investigated by means of an extensive parametric study on a theoretical model described in this paper. From a perspective of control mechanism, it was found that there are several control mechanisms working simultaneously in bone remodeling which is a complex process. Typically, an extensive parametric study was carried out for investigating model parameter space related to cell differentiation and apoptosis which can describe the fundamental cell lineage behaviors. After analyzing all the combinations of 728 permutations in six model parameters, we have identified a small number of parameter combinations that can lead to physiologically realistic responses which are similar to theoretically idealized physiological responses. The results presented in the work enhanced our understanding on mechanical bone remodeling and the identified control mechanisms can help researchers to develop combined pharmacological-mechanical therapies to treat bone loss diseases such as osteoporosis.

Principle Of Non-Regression And Social Security: Security And Trust Protection, Reservation Of The Possible And Non-Regression In The Fundamental Social Rights

Directory of Open Access Journals (Sweden)

Rodrigo Garcia Schwarz

2016-12-01

Full Text Available This paper aims to explain and analyze, from the perspective of the material and effective dimensions of fundamental social rights, questions that concern the relevance of security and trust for the social pact and, as a consequence, to the non-regression in the fundamental social rights in general and in the social security in particular. It reveals that, while the retrogression is not absolute, retrogression must be fully justified. The research is descriptive and explanatory, documentary-bibliographical.

In vivo time-resolved microtomography reveals the mechanics of the blowfly flight motor.

Directory of Open Access Journals (Sweden)

Simon M Walker

2014-03-01

Full Text Available Dipteran flies are amongst the smallest and most agile of flying animals. Their wings are driven indirectly by large power muscles, which cause cyclical deformations of the thorax that are amplified through the intricate wing hinge. Asymmetric flight manoeuvres are controlled by 13 pairs of steering muscles acting directly on the wing articulations. Collectively the steering muscles account for <3% of total flight muscle mass, raising the question of how they can modulate the vastly greater output of the power muscles during manoeuvres. Here we present the results of a synchrotron-based study performing micrometre-resolution, time-resolved microtomography on the 145 Hz wingbeat of blowflies. These data represent the first four-dimensional visualizations of an organism's internal movements on sub-millisecond and micrometre scales. This technique allows us to visualize and measure the three-dimensional movements of five of the largest steering muscles, and to place these in the context of the deforming thoracic mechanism that the muscles actuate. Our visualizations show that the steering muscles operate through a diverse range of nonlinear mechanisms, revealing several unexpected features that could not have been identified using any other technique. The tendons of some steering muscles buckle on every wingbeat to accommodate high amplitude movements of the wing hinge. Other steering muscles absorb kinetic energy from an oscillating control linkage, which rotates at low wingbeat amplitude but translates at high wingbeat amplitude. Kinetic energy is distributed differently in these two modes of oscillation, which may play a role in asymmetric power management during flight control. Structural flexibility is known to be important to the aerodynamic efficiency of insect wings, and to the function of their indirect power muscles. We show that it is integral also to the operation of the steering muscles, and so to the functional flexibility of the

In vivo time-resolved microtomography reveals the mechanics of the blowfly flight motor.

Science.gov (United States)

Walker, Simon M; Schwyn, Daniel A; Mokso, Rajmund; Wicklein, Martina; Müller, Tonya; Doube, Michael; Stampanoni, Marco; Krapp, Holger G; Taylor, Graham K

2014-03-01

Dipteran flies are amongst the smallest and most agile of flying animals. Their wings are driven indirectly by large power muscles, which cause cyclical deformations of the thorax that are amplified through the intricate wing hinge. Asymmetric flight manoeuvres are controlled by 13 pairs of steering muscles acting directly on the wing articulations. Collectively the steering muscles account for flight muscle mass, raising the question of how they can modulate the vastly greater output of the power muscles during manoeuvres. Here we present the results of a synchrotron-based study performing micrometre-resolution, time-resolved microtomography on the 145 Hz wingbeat of blowflies. These data represent the first four-dimensional visualizations of an organism's internal movements on sub-millisecond and micrometre scales. This technique allows us to visualize and measure the three-dimensional movements of five of the largest steering muscles, and to place these in the context of the deforming thoracic mechanism that the muscles actuate. Our visualizations show that the steering muscles operate through a diverse range of nonlinear mechanisms, revealing several unexpected features that could not have been identified using any other technique. The tendons of some steering muscles buckle on every wingbeat to accommodate high amplitude movements of the wing hinge. Other steering muscles absorb kinetic energy from an oscillating control linkage, which rotates at low wingbeat amplitude but translates at high wingbeat amplitude. Kinetic energy is distributed differently in these two modes of oscillation, which may play a role in asymmetric power management during flight control. Structural flexibility is known to be important to the aerodynamic efficiency of insect wings, and to the function of their indirect power muscles. We show that it is integral also to the operation of the steering muscles, and so to the functional flexibility of the insect flight motor.

Ultralight porous metals: From fundamentals to applications

Science.gov (United States)

Lu, Tianjian

2002-10-01

Over the past few years a number of low cost metallic foams have been produced and used as the core of sandwich panels and net shaped parts. The main aim is to develop lightweight structures which are stiff, strong, able to absorb large amount of energy and cheap for application in the transport and construction industries. For example, the firewall between the engine and passenger compartment of an automobile must have adequate mechanical strength, good energy and sound absorbing properties, and adequate fire retardance. Metal foams provide all of these features, and are under serious consideration for this applications by a number of automobile manufacturers (e.g., BMW and Audi). Additional specialized applications for foam-cored sandwich panels range from heat sinks for electronic devices to crash barriers for automobiles, from the construction panels in lifts on aircraft carriers to the luggage containers of aircraft, from sound proofing walls along railway tracks and highways to acoustic absorbers in lean premixed combustion chambers. But there is a problem. Before metallic foams can find a widespread application, their basic properties must be measured, and ideally modeled as a function of microstructural details, in order to be included in a design. This work aims at reviewing the recent progress and presenting some new results on fundamental research regarding the micromechanical origins of the mechanical, thermal, and acoustic properties of metallic foams.

Ultralight porous metals. From fundamentals to applications

International Nuclear Information System (INIS)

Lu, T.

2002-01-01

Over the past few years a number of low cost metallic foams for application as the core of sandwich panels and net shaped parts have been produced. The main aim is to develop lightweight structures which are stiff, strong, absorb large amount of energy and are cheap, for application in the transport and construction industries. For example, the firewall between the engine and passenger compartment of an automobile must have adequate mechanical strength, good energy and sound absorbing properties, and adequate fire retardance. Metal foams provide all of these features, and are under serious scrutiny for this applications by a number of automobile manufacturers (e.g., BMW and Audi). Additional specialized applications for foam-cored sandwich panels range from heat sinks for electronic devices to crash barriers for automobiles, from the construction panels in lifts on aircraft carriers to the luggage containers of aircraft, from sound proofing walls along railway tracks and highways to acoustic absorbers in lean premixed combustion chambers. But there is a problem. Before metallic foams can find widespread application, their basic properties must be measured, and ideally modeled as a function of microstructural details, in order to give a design capability. This work aims at reviewing recent progress and present some new results on fundamental research regarding the micromechanical origins of the mechanical, thermal, and acoustic properties of metallic foams. (author)

Metatranscriptomics reveals the molecular mechanism of large granule formation in granular anammox reactor

KAUST Repository

Bagchi, Samik

2016-06-20

Granules enriched with anammox bacteria are essential in enhancing the treatment of ammonia-rich wastewater, but little is known about how anammox bacteria grow and multiply inside granules. Here, we combined metatranscriptomics, quantitative PCR and 16S rRNA gene sequencing to study the changes in community composition, metabolic gene content and gene expression in a granular anammox reactor with the objective of understanding the molecular mechanism of anammox growth and multiplication that led to formation of large granules. Size distribution analysis revealed the spatial distribution of granules in which large granules having higher abundance of anammox bacteria (genus Brocadia) dominated the bottom biomass. Metatranscriptomics analysis detected all the essential transcripts for anammox metabolism. During the later stage of reactor operation, higher expression of ammonia and nitrite transport proteins and key metabolic enzymes mainly in the bottom large granules facilitated anammox bacteria activity. The high activity resulted in higher growth and multiplication of anammox bacteria and expanded the size of the granules. This conceptual model for large granule formation proposed here may assist in the future design of anammox processes for mainstream wastewater treatment.

The gating mechanism of the human aquaporin 5 revealed by molecular dynamics simulations.

Directory of Open Access Journals (Sweden)

Lorant Janosi

Full Text Available Aquaporins are protein channels located across the cell membrane with the role of conducting water or other small sugar alcohol molecules (aquaglyceroporins. The high-resolution X-ray structure of the human aquaporin 5 (HsAQP5 shows that HsAQP5, as all the other known aquaporins, exhibits tetrameric structure. By means of molecular dynamics simulations we analyzed the role of spontaneous fluctuations on the structural behavior of the human AQP5. We found that different conformations within the tetramer lead to a distribution of monomeric channel structures, which can be characterized as open or closed. The switch between the two states of a channel is a tap-like mechanism at the cytoplasmic end which regulates the water passage through the pore. The channel is closed by a translation of the His67 residue inside the pore. Moreover, water permeation rate calculations revealed that the selectivity filter, located at the other end of the channel, regulates the flow rate of water molecules when the channel is open, by locally modifying the orientation of His173. Furthermore, the calculated permeation rates of a fully open channel are in good agreement with the reported experimental value.

Fundamentals of Fire Phenomena

DEFF Research Database (Denmark)

Quintiere, James

analyses. Fire phenomena encompass everything about the scientific principles behind fire behaviour. Combining the principles of chemistry, physics, heat and mass transfer, and fluid dynamics necessary to understand the fundamentals of fire phenomena, this book integrates the subject into a clear...

Industrial separation processes : fundamentals

NARCIS (Netherlands)

Haan, de A.B.; Bosch, Hans

2013-01-01

Separation processes on an industrial scale comprise well over half of the capital and operating costs. They are basic knowledge in every chemical engineering and process engineering study. This book provides comprehensive and fundamental knowledge of university teaching in this discipline,

Fundamentals of plasma physics

CERN Document Server

Bittencourt, J A

1986-01-01

A general introduction designed to present a comprehensive, logical and unified treatment of the fundamentals of plasma physics based on statistical kinetic theory. Its clarity and completeness make it suitable for self-learning and self-paced courses. Problems are included.

Fundamentals of colour awareness: a literature review

Directory of Open Access Journals (Sweden)

A. Rubin

2005-12-01

Full Text Available A description of some of the basic or funda-mental aspects of the colour sensory mechanism will be provided here, based on modern ideas and literature, with reference specifically to the likely origins and evolution of colour vision.  The mo-lecular basis for colour awareness and the human colour pathway will also be considered in some detail. This paper intends to provide the theoreti-cal and philosophical basis for further papers that will introduce a modern and original computer- based  method  for  more  comprehensive  colour vision  assessment.    This  new  approach,  to  be fully described in later manuscripts, may contrib-ute towards improvements in understanding and knowledge of human colour perception and its measurement, still perhaps a relatively under-ex-plored or neglected field of study within optom-etry and ophthalmology.

Cosmic rays and tests of fundamental principles

Science.gov (United States)

Gonzalez-Mestres, Luis

2011-03-01

It is now widely acknowledged that cosmic rays experiments can test possible new physics directly generated at the Planck scale or at some other fundamental scale. By studying particle properties at energies far beyond the reach of any man-made accelerator, they can yield unique checks of basic principles. A well-known example is provided by possible tests of special relativity at the highest cosmic-ray energies. But other essential ingredients of standard theories can in principle be tested: quantum mechanics, uncertainty principle, energy and momentum conservation, effective space-time dimensions, hamiltonian and lagrangian formalisms, postulates of cosmology, vacuum dynamics and particle propagation, quark and gluon confinement, elementariness of particles…Standard particle physics or string-like patterns may have a composite origin able to manifest itself through specific cosmic-ray signatures. Ultra-high energy cosmic rays, but also cosmic rays at lower energies, are probes of both "conventional" and new Physics. Status, prospects, new ideas, and open questions in the field are discussed.

Cosmic rays and tests of fundamental principles

International Nuclear Information System (INIS)

Gonzalez-Mestres, Luis

2011-01-01

It is now widely acknowledged that cosmic rays experiments can test possible new physics directly generated at the Planck scale or at some other fundamental scale. By studying particle properties at energies far beyond the reach of any man-made accelerator, they can yield unique checks of basic principles. A well-known example is provided by possible tests of special relativity at the highest cosmic-ray energies. But other essential ingredients of standard theories can in principle be tested: quantum mechanics, uncertainty principle, energy and momentum conservation, effective space-time dimensions, hamiltonian and lagrangian formalisms, postulates of cosmology, vacuum dynamics and particle propagation, quark and gluon confinement, elementariness of particles... Standard particle physics or string-like patterns may have a composite origin able to manifest itself through specific cosmic-ray signatures. Ultra-high energy cosmic rays, but also cosmic rays at lower energies, are probes of both 'conventional' and new Physics. Status, prospects, new ideas, and open questions in the field are discussed.

The complete genome and proteome of Laribacter hongkongensis reveal potential mechanisms for adaptations to different temperatures and habitats.

Science.gov (United States)

Woo, Patrick C Y; Lau, Susanna K P; Tse, Herman; Teng, Jade L L; Curreem, Shirly O T; Tsang, Alan K L; Fan, Rachel Y Y; Wong, Gilman K M; Huang, Yi; Loman, Nicholas J; Snyder, Lori A S; Cai, James J; Huang, Jian-Dong; Mak, William; Pallen, Mark J; Lok, Si; Yuen, Kwok-Yung

2009-03-01

Laribacter hongkongensis is a newly discovered Gram-negative bacillus of the Neisseriaceae family associated with freshwater fish-borne gastroenteritis and traveler's diarrhea. The complete genome sequence of L. hongkongensis HLHK9, recovered from an immunocompetent patient with severe gastroenteritis, consists of a 3,169-kb chromosome with G+C content of 62.35%. Genome analysis reveals different mechanisms potentially important for its adaptation to diverse habitats of human and freshwater fish intestines and freshwater environments. The gene contents support its phenotypic properties and suggest that amino acids and fatty acids can be used as carbon sources. The extensive variety of transporters, including multidrug efflux and heavy metal transporters as well as genes involved in chemotaxis, may enable L. hongkongensis to survive in different environmental niches. Genes encoding urease, bile salts efflux pump, adhesin, catalase, superoxide dismutase, and other putative virulence factors-such as hemolysins, RTX toxins, patatin-like proteins, phospholipase A1, and collagenases-are present. Proteomes of L. hongkongensis HLHK9 cultured at 37 degrees C (human body temperature) and 20 degrees C (freshwater habitat temperature) showed differential gene expression, including two homologous copies of argB, argB-20, and argB-37, which encode two isoenzymes of N-acetyl-L-glutamate kinase (NAGK)-NAGK-20 and NAGK-37-in the arginine biosynthesis pathway. NAGK-20 showed higher expression at 20 degrees C, whereas NAGK-37 showed higher expression at 37 degrees C. NAGK-20 also had a lower optimal temperature for enzymatic activities and was inhibited by arginine probably as negative-feedback control. Similar duplicated copies of argB are also observed in bacteria from hot springs such as Thermus thermophilus, Deinococcus geothermalis, Deinococcus radiodurans, and Roseiflexus castenholzii, suggesting that similar mechanisms for temperature adaptation may be employed by other

Contact geometry and quantum mechanics

Science.gov (United States)

Herczeg, Gabriel; Waldron, Andrew

2018-06-01

We present a generally covariant approach to quantum mechanics in which generalized positions, momenta and time variables are treated as coordinates on a fundamental "phase-spacetime". We show that this covariant starting point makes quantization into a purely geometric flatness condition. This makes quantum mechanics purely geometric, and possibly even topological. Our approach is especially useful for time-dependent problems and systems subject to ambiguities in choices of clock or observer. As a byproduct, we give a derivation and generalization of the Wigner functions of standard quantum mechanics.

Latent Fundamentals Arbitrage with a Mixed Effects Factor Model

Directory of Open Access Journals (Sweden)

Andrei Salem Gonçalves

2012-09-01

Full Text Available We propose a single-factor mixed effects panel data model to create an arbitrage portfolio that identifies differences in firm-level latent fundamentals. Furthermore, we show that even though the characteristics that affect returns are unknown variables, it is possible to identify the strength of the combination of these latent fundamentals for each stock by following a simple approach using historical data. As a result, a trading strategy that bought the stocks with the best fundamentals (strong fundamentals portfolio and sold the stocks with the worst ones (weak fundamentals portfolio realized significant risk-adjusted returns in the U.S. market for the period between July 1986 and June 2008. To ensure robustness, we performed sub period and seasonal analyses and adjusted for trading costs and we found further empirical evidence that using a simple investment rule, that identified these latent fundamentals from the structure of past returns, can lead to profit.

Fundamental solutions in piezoelectricity. Penny-shaped crack solution

International Nuclear Information System (INIS)

Dyka, Ewa; Rogowski, Bogdan

2006-01-01

The problem of electroelasticity for piezoelectric materials is considered. For axially symmetric states three potentials are introduced, which determine the displacements, the electric potentials, the stresses, the components of the electric field vector and the electric displacements in a piezoelectric body. These fundamental solutions are utilized to solve the penny-shaped crack problem. Two cases of boundary-value problems are considered, namely the permeable and impermeable crack boundary conditions. Exact solutions are obtained for elastic and electric fields. The main results are the stress intensity factor for singular stress and the electric displacement intensity factor. The numerical results are presented graphically to show the influence of applied mechanical and electrical loading on the analyzed quantities and to clarify the effect of anisotropy of piezoelectric materials. It is show that the influence of anisotropy of the materials on these fields is significant

Fundamental and Harmonic Oscillations in Neighboring Coronal Loops

Science.gov (United States)

Li, Hongbo; Liu, Yu; Vai Tam, Kuan

2017-06-01

We present observations of multimode (fundamental and harmonic) oscillations in a loop system, which appear to be simultaneously excited by a GOES C-class flare. Analysis of the periodic oscillations reveals that (1) the primary loop with a period of P a ≈ 4 minutes and a secondary loop with two periods of P a ≈ 4 minutes and P b ≈ 2 minutes are detected simultaneously in closely spaced loop strands; (2) both oscillation components have their peak amplitudes near the loop apex, while in the second loop the low-frequency component P a dominates in a loop segment that is two times larger than the high-frequency component P b ; (3) the harmonic mode P b shows the largest deviation from a sinusoidal loop shape at the loop apex. We conclude that multiple harmonic modes with different displacement profiles can be excited simultaneously even in closely spaced strands, similar to the overtones of a violin string.

Fundamental mechanisms for conversion of volatiles in biomass and waste combustion. Final report

Energy Technology Data Exchange (ETDEWEB)

Glarborg, P.; Hindiyarti, L.; Marshall, P.; Livbjerg, H.; Dagaut, P.; Jensen, Anker; Frandsen, Flemming

2007-03-15

This project deals with the volatile oxidation chemistry in biomass and waste fired systems, emphasizing reactions important for pollutants emissions (NO{sub x}, SO{sub 2}, HCl, aerosols). The project aims to extend existing models and databases with a number of chemical subsystems that are presently not well understood, but are particularly important in connection with combustion of biomass and waste. The project is divided into 3 tasks. Task 1: Conversion of chlorine, sulfur and alkali gas phase components in combustion of biomass. Task 2: Formation mechanisms for NO{sub x} in the freeboard of grate combustion of biomass. Task 3: Oxidation mechanisms for oxygenated hydrocarbons in the volatiles from pyrolysis of biomass. (au)

Grenoble Fundamental Research Department

International Nuclear Information System (INIS)

1979-01-01

A summary of the various activities of the Fundamental Research Institute, Grenoble, France is given. The following fields are covered: Nuclear physics, solid state physics, physical chemistry, biology and advanced techniques. Fore more detailed descriptions readers are referred to scientific literature [fr

Fundamentals and Optimal Institutions

DEFF Research Database (Denmark)

Gonzalez-Eiras, Martin; Harmon, Nikolaj Arpe; Rossi, Martín

2016-01-01

of regulatory institutions such as revenue sharing, salary caps or luxury taxes. We show, theoretically and empirically, that these large differences in adopted institutions can be rationalized as optimal responses to differences in the fundamental characteristics of the sports being played. This provides...

Fundamental superstrings as holograms

International Nuclear Information System (INIS)

Dabholkar, A.; Murthy, S.

2007-06-01

The worldsheet of a macroscopic fundamental superstring in the Green-Schwarz light-cone gauge is viewed as a possible boundary hologram of the near horizon region of a small black string. For toroidally compactified strings, the hologram has global symmetries of AdS 3 x S d-1 x T 8-d ( d = 3, . . . , 8), only some of which extend to local conformal symmetries. We construct the bulk string theory in detail for the particular case of d = 3. The symmetries of the hologram are correctly reproduced from this exact worldsheet description in the bulk. Moreover, the central charge of the boundary Virasoro algebra obtained from the bulk agrees with the Wald entropy of the associated small black holes. This construction provides an exact CFT description of the near horizon region of small black holes both in Type-II and heterotic string theory arising from multiply wound fundamental superstrings. (author)

Fundamental superstrings as holograms

International Nuclear Information System (INIS)

Dabholkar, Atish; Murthy, Sameer

2008-01-01

The worldsheet of a macroscopic fundamental superstring in the Green-Schwarz light-cone gauge is viewed as a possible boundary hologram of the near horizon region of a small black string. For toroidally compactified strings, the hologram has global symmetries of AdS 3 x S d-1 x T 8-d (d = 3, ..., 8), only some of which extend to local conformal symmetries. We construct the bulk string theory in detail for the particular case of d = 3. The symmetries of the hologram are correctly reproduced from this exact worldsheet description in the bulk. Moreover, the central charge of the boundary Virasoro algebra obtained from the bulk agrees with the Wald entropy of the associated small black holes. This construction provides an exact CFT description of the near horizon region of small black holes both in Type-II and heterotic string theory arising from multiply wound fundamental superstrings

A microscopic investigation of failure mechanisms in a triaxially braided polyimide composite at room and elevated temperatures

International Nuclear Information System (INIS)

Montesano, John; Fawaz, Zouheir; Poon, Cheung; Behdinan, Kamran

2014-01-01

Highlights: • Experimental investigation on a unique braided polyimide composite material. • Tensile static and fatigue tests at both room temperature and elevated temperature. • Tests reveal that elevated temperature causes a reduction in microscopic damage. • Temperature-dependent damage development caused a reduction in fatigue life. • A fundamental understanding of the novel material behavior was achieved. - Abstract: An experimental investigation is conducted on a unique triaxially braided polyimide composite material in order to track the development of microscopic damage leading to failure. Tensile static and fatigue tests are conducted at both room and elevated temperatures. Edge replication and scanning electron microscopy are employed to track damage development and to identify failure mechanisms, respectively. Static tests reveal that although the elevated temperature environment does not significantly alter the mechanical properties of the composite, its influence on the development of microscopic damage development is notable. The dominant damage mechanism of braider yarn cracking is mitigated at elevated temperatures as a direct result of resin softening, which is also the case for the fatigue test specimens. The result of the temperature-dependent microscopic damage development is a reduction in the fatigue lives at elevated temperatures. This study yielded an improved understanding of microscopic damage mechanisms and local deformation behavior for an advanced composite material, which is valuable for designers

Analysis of HIV-1 intersubtype recombination breakpoints suggests region with high pairing probability may be a more fundamental factor than sequence similarity affecting HIV-1 recombination.

Science.gov (United States)

Jia, Lei; Li, Lin; Gui, Tao; Liu, Siyang; Li, Hanping; Han, Jingwan; Guo, Wei; Liu, Yongjian; Li, Jingyun

2016-09-21

With increasing data on HIV-1, a more relevant molecular model describing mechanism details of HIV-1 genetic recombination usually requires upgrades. Currently an incomplete structural understanding of the copy choice mechanism along with several other issues in the field that lack elucidation led us to perform an analysis of the correlation between breakpoint distributions and (1) the probability of base pairing, and (2) intersubtype genetic similarity to further explore structural mechanisms. Near full length sequences of URFs from Asia, Europe, and Africa (one sequence/patient), and representative sequences of worldwide CRFs were retrieved from the Los Alamos HIV database. Their recombination patterns were analyzed by jpHMM in detail. Then the relationships between breakpoint distributions and (1) the probability of base pairing, and (2) intersubtype genetic similarities were investigated. Pearson correlation test showed that all URF groups and the CRF group exhibit the same breakpoint distribution pattern. Additionally, the Wilcoxon two-sample test indicated a significant and inexplicable limitation of recombination in regions with high pairing probability. These regions have been found to be strongly conserved across distinct biological states (i.e., strong intersubtype similarity), and genetic similarity has been determined to be a very important factor promoting recombination. Thus, the results revealed an unexpected disagreement between intersubtype similarity and breakpoint distribution, which were further confirmed by genetic similarity analysis. Our analysis reveals a critical conflict between results from natural HIV-1 isolates and those from HIV-1-based assay vectors in which genetic similarity has been shown to be a very critical factor promoting recombination. These results indicate the region with high-pairing probabilities may be a more fundamental factor affecting HIV-1 recombination than sequence similarity in natural HIV-1 infections. Our

Multiple roles of integrin-linked kinase in epidermal development, maturation and pigmentation revealed by molecular profiling.

Directory of Open Access Journals (Sweden)

David Judah

Full Text Available Integrin-linked kinase (ILK is an important scaffold protein that mediates a variety of cellular responses to integrin stimulation by extracellular matrix proteins. Mice with epidermis-restricted inactivation of the Ilk gene exhibit pleiotropic phenotypic defects, including impaired hair follicle morphogenesis, reduced epidermal adhesion to the basement membrane, compromised epidermal integrity, as well as wasting and failure to thrive leading to perinatal death. To better understand the underlying molecular mechanisms that cause such a broad range of alterations, we investigated the impact of Ilk gene inactivation on the epidermis transcriptome. Microarray analysis showed over 700 differentially regulated mRNAs encoding proteins involved in multiple aspects of epidermal function, including keratinocyte differentiation and barrier formation, inflammation, regeneration after injury, and fundamental epidermal developmental pathways. These studies also revealed potential effects on genes not previously implicated in ILK functions, including those important for melanocyte and melanoblast development and function, regulation of cytoskeletal dynamics, and homeobox genes. This study shows that ILK is a critical regulator of multiple aspects of epidermal function and homeostasis, and reveals the previously unreported involvement of ILK not only in epidermal differentiation and barrier formation, but also in melanocyte genesis and function.

Multiple roles of integrin-linked kinase in epidermal development, maturation and pigmentation revealed by molecular profiling.

Science.gov (United States)

Judah, David; Rudkouskaya, Alena; Wilson, Ryan; Carter, David E; Dagnino, Lina

2012-01-01

Integrin-linked kinase (ILK) is an important scaffold protein that mediates a variety of cellular responses to integrin stimulation by extracellular matrix proteins. Mice with epidermis-restricted inactivation of the Ilk gene exhibit pleiotropic phenotypic defects, including impaired hair follicle morphogenesis, reduced epidermal adhesion to the basement membrane, compromised epidermal integrity, as well as wasting and failure to thrive leading to perinatal death. To better understand the underlying molecular mechanisms that cause such a broad range of alterations, we investigated the impact of Ilk gene inactivation on the epidermis transcriptome. Microarray analysis showed over 700 differentially regulated mRNAs encoding proteins involved in multiple aspects of epidermal function, including keratinocyte differentiation and barrier formation, inflammation, regeneration after injury, and fundamental epidermal developmental pathways. These studies also revealed potential effects on genes not previously implicated in ILK functions, including those important for melanocyte and melanoblast development and function, regulation of cytoskeletal dynamics, and homeobox genes. This study shows that ILK is a critical regulator of multiple aspects of epidermal function and homeostasis, and reveals the previously unreported involvement of ILK not only in epidermal differentiation and barrier formation, but also in melanocyte genesis and function.

Transgenic Analysis of the Leishmania MAP Kinase MPK10 Reveals an Auto-inhibitory Mechanism Crucial for Stage-Regulated Activity and Parasite Viability

DEFF Research Database (Denmark)

Cayla, M.; Rachidi, N.; Leclercq, O.

2014-01-01

Protozoan pathogens of the genus Leishmania have evolved unique signaling mechanisms that can sense changes in the host environment and trigger adaptive stage differentiation essential for host cell infection. The signaling mechanisms underlying parasite development remain largely elusive even...... though Leishmania mitogen-activated protein kinases (MAPKs) have been linked previously to environmentally induced differentiation and virulence. Here, we unravel highly unusual regulatory mechanisms for Leishmania MAP kinase 10 (MPK10). Using a transgenic approach, we demonstrate that MPK10 is stage...... at position 395 that could be implicated in kinase regulation. Finally, we uncovered a feedback loop that limits MPK10 activity through dephosphorylation of the tyrosine residue of the TxY motif. Together our data reveal novel aspects of protein kinase regulation in Leishmania, and propose MPK10...

Effective mechanic training

International Nuclear Information System (INIS)

Burdge, R.E.

1979-01-01

The need for the training of mechanics is discussed, and the increased interest within the utility industry of placing a similar importance on this training as it has traditionally placed on operator training, is expressed. Effective approaches and techniques are described. Fundamental mechanical maintenance concepts and their practical application are discussed, including the use of supporting video programs. The importance of follow-up practical shop exercise which reinforces classroom instruction is stressed, drawing from practical utility experience. Utilizing success in training as a measure of eligibility for advancement is discussed as well as the interface between training and the company bargaining unit

A multidimensional analysis of physiological and mechanical ...

African Journals Online (AJOL)

Journal of Fundamental and Applied Sciences ... investigates the various physiological and mechanical techniques employed by archers of varying skill levels. ... Keywords: archery; muscle activations; heart rate; bow movement; postural sway ...

Variation of nonlinearity parameter at low fundamental amplitudes

Science.gov (United States)

Barnard, Daniel J.

1999-04-01

Recent harmonic generation measurements of the nonlinearity parameter β in polycrystalline Cu-Al alloys have shown a transition to lower values at low fundamental amplitude levels. Values for β at high (>10 Å) fundamental levels are in the range predicted by single-crystal second- and third-order elastic constants while lower fundamental levels (alloy by others. The source of the effect is unclear but initial results may require a reexamination of current methods for measurement of third-order elastic constants.

Vocal fold elasticity of the Rocky Mountain elk (Cervus elaphus nelsoni) – producing high fundamental frequency vocalization with a very long vocal fold

OpenAIRE

Riede, Tobias; Titze, Ingo R.

2008-01-01

The vocal folds of male Rocky Mountain elk (Cervus elaphus nelsoni) are about 3 cm long. If fundamental frequency were to be predicted by a simple vibrating string formula, as is often done for the human larynx, such long vocal folds would bear enormous stress to produce the species-specific mating call with an average fundamental frequency of 1 kHz. Predictions would be closer to 50 Hz. Vocal fold histology revealed the presence of a large vocal ligament between the vocal fold epithelium and...

Fracture mechanics. With an introduction to micromechanics

International Nuclear Information System (INIS)

Gross, D.

2006-01-01

Concerned with the fundamental concepts and methods of fracture mechanics and micromechanics, Fracture Mechanics primarily focuses on the mechanical description of the fracture process; however, material specific aspects are also discussed. The presentation of continuum mechanical and phenomenological foundations is followed by an introduction into classical failure hypotheses. A major part of the book is devoted to linear elastic and elastic-plastic fracture mechanics. Further subjects are creep fracture, dynamic fracture mechanics, damage mechanics, probabilistic fracture mechanics, failure of thin films and fracture of piezoelectric materials. The book also contains an extensive introduction into micromechanics. Self-contained and well-illustrated, this text serves as a graduate-level text and reference

PERM Hypothesis: The Fundamental Machinery Able to Elucidate the Role of Xenobiotics and Hormesis in Cell Survival and Homeostasis

Directory of Open Access Journals (Sweden)

Salvatore Chirumbolo

2017-01-01

Full Text Available In this article the Proteasome, Endoplasmic Reticulum and Mitochondria (PERM hypothesis is discussed. The complex machinery made by three homeostatic mechanisms involving the proteasome (P, endoplasmic reticulum (ER and mitochondria (M is addressed in order to elucidate the beneficial role of many xenobiotics, either trace metals or phytochemicals, which are spread in the human environment and in dietary habits, exerting their actions on the mechanisms underlying cell survival (apoptosis, cell cycle regulation, DNA repair and turnover, autophagy and stress response. The “PERM hypothesis” suggests that xenobiotics can modulate this central signaling and the regulatory engine made fundamentally by the ER, mitochondria and proteasome, together with other ancillary components such as peroxisomes, by acting on the energetic balance, redox system and macromolecule turnover. In this context, reactive species and stressors are fundamentally signalling molecules that could act as negative-modulating signals if PERM-mediated control is offline, impaired or dysregulated, as occurs in metabolic syndrome, degenerative disorders, chronic inflammation and cancer. Calcium is an important oscillatory input of this regulation and, in this hypothesis, it might play a role in maintaining the correct rhythm of this PERM modulation, probably chaotic in its nature, and guiding cells to a more drastic decision, such as apoptosis. The commonest effort sustained by cells is to maintain their survival balance and the proterome has the fundamental task of supporting this mechanism. Mild stress is probably the main stimulus in this sense. Hormesis is therefore re-interpreted in the light of this hypothetical model and that experimental evidence arising from flavonoid and hormesis reasearch.

Fundamental understanding and rational design of high energy structural microbatteries

International Nuclear Information System (INIS)

Wang, Yuxing; Li, Qiuyan; Cartmell, Samuel; Li, Huidong; Mendoza, Sarah

2017-01-01

We present that microbatteries play a critical role in determining the lifetime of downsized sensors, wearable devices, medical applications, and animal acoustic telemetry transmitters among others. More often, structural batteries are required from the perspective of aesthetics and space utilization, which is however rarely explored. Herein, we discuss the fundamental issues associated with the rational design of practically usable high energy microbatteries. The tubular shape of the cell further allows the flexible integration of microelectronics. A functioning acoustic micro-transmitter continuously powered by this tubular battery has been successfully demonstrated. Finally, multiple design features adopted to accommodate large mechanical stress during the rolling process are discussed providing new insights in designing the structural microbatteries for emerging technologies.

THE FUNDAMENTS OF EXPLANATORY CAUSES

Directory of Open Access Journals (Sweden)

Lavinia Mihaela VLĂDILĂ

2015-07-01

Full Text Available The new Criminal Code in the specter of the legal life the division of causes removing the criminal feature of the offence in explanatory causes and non-attributable causes. This dichotomy is not without legal and factual fundaments and has been subjected to doctrinaire debates even since the period when the Criminal Code of 1969 was still in force. From our perspective, one of the possible legal fundaments of the explanatory causes results from that the offence committed is based on the protection of a right at least equal with the one prejudiced by the action of aggression, salvation, by the legal obligation imposed or by the victim’s consent.

O sofrimento psíquico na perspectiva da psicopatologia fundamental Psychic suffering from the fundamental psychopathology perspective

Directory of Open Access Journals (Sweden)

Paulo Ceccarelli

2005-12-01

Full Text Available Partindo da palavra PSICOPATOLOGIA, o autor mostra, de forma resumida, como cada contexto histórico tentou "decompor" o sofrimento psíquico em seus elementos de base para classificá-lo, estudá-lo e tratá-lo. Após uma breve apresentação da psicopatologia na contemporaneidade, o autor introduz os pressupostos da Psicopatologia Fundamental e suas contribuições na compreensão do sofrimento psíquico. Ainda que não seja objetivo do texto participar do debate atual sobre as diretrizes curriculares que norteiam a formação do psicólogo, o autor toma o estudo do conhecimento (logos da alma (psyché - a psicologia - como exemplo de um dos campos de aplicação da Psicopatologia Fundamental.From the word PSYCHOPATHOLOGY the author briefly shows how each historical context had its own way to decompose psychic suffering in order to classify, study and search for its cure. After a short discussion about psychopathology in contemporaneity the author introduces the theoretical bases of Fundamental Psychopathology and its contributions to understanding psychic suffering. Although this text does not claim to participate in the debate about psychology students training, the author exemplifies through the study of the soul (psyche knowledge (logos one of the applications of Fundamental Psychopathology.

Is G a conversion factor or a fundamental unit?

OpenAIRE

Fiorentini, G.; Okun, L.; Vysotsky, M.

2001-01-01

By using fundamental units c, h, G as conversion factors one can easily transform the dimensions of all observables. In particular one can make them all ``geometrical'', or dimensionless. However this has no impact on the fact that there are three fundamental units, G being one of them. Only experiment can tell us whether G is basically fundamental.

Fundamental Metallurgy of Solidification

DEFF Research Database (Denmark)

Tiedje, Niels

2004-01-01

The text takes the reader through some fundamental aspects of solidification, with focus on understanding the basic physics that govern solidification in casting and welding. It is described how the first solid is formed and which factors affect nucleation. It is described how crystals grow from...

Fast fundamental frequency estimation

DEFF Research Database (Denmark)

Nielsen, Jesper Kjær; Jensen, Tobias Lindstrøm; Jensen, Jesper Rindom

2017-01-01

Modelling signals as being periodic is common in many applications. Such periodic signals can be represented by a weighted sum of sinusoids with frequencies being an integer multiple of the fundamental frequency. Due to its widespread use, numerous methods have been proposed to estimate the funda...

Fundamentals of a graded approach to safety-related equipment setpoints

International Nuclear Information System (INIS)

Woodruff, B.A.; Cash, J.S. Jr.; Bockhorst, R.M.

1993-01-01

The concept of using a graded approach to reconstitute instrument setpoints associated with safety-related equipment was first presented to the industry by the U.S. Nuclear Regulatory Commission during the 1992 ISA/POWID Symposium in Kansas City, Missouri. The graded approach establishes that the manner in which a utility analyzes and documents setpoints is related to each setpoint's relative importance to safety. This allows a utility to develop separate requirements for setpoints of varying levels of safety significance. A graded approach to setpoints is a viable strategy that minimizes extraneous effort expended in resolving difficult issues that arise when formal setpoint methodology is applied blindly to all setpoints. Close examination of setpoint methodology reveals that the application of a graded approach is fundamentally dependent on the analytical basis of each individual setpoint

Fundamentals and applications of ultrasonic waves

CERN Document Server

Cheeke, J David N

2002-01-01

Ultrasonics. A subject with applications across all the basic sciences, engineering, medicine, and oceanography, yet even the broader topic of acoustics is now rarely offered at undergraduate levels. Ultrasonics is addressed primarily at the doctoral level, and texts appropriate for beginning graduate students or newcomers to the field are virtually nonexistent.Fundamentals and Applications of Ultrasonic Waves fills that void. Designed specifically for senior undergraduates, beginning graduate students, and those just entering the field, it begins with the fundamentals, but goes well beyond th

STEP and fundamental physics

Science.gov (United States)

Overduin, James; Everitt, Francis; Worden, Paul; Mester, John

2012-09-01

The Satellite Test of the Equivalence Principle (STEP) will advance experimental limits on violations of Einstein's equivalence principle from their present sensitivity of two parts in 1013 to one part in 1018 through multiple comparison of the motions of four pairs of test masses of different compositions in a drag-free earth-orbiting satellite. We describe the experiment, its current status and its potential implications for fundamental physics. Equivalence is at the heart of general relativity, our governing theory of gravity and violations are expected in most attempts to unify this theory with the other fundamental interactions of physics, as well as in many theoretical explanations for the phenomenon of dark energy in cosmology. Detection of such a violation would be equivalent to the discovery of a new force of nature. A null result would be almost as profound, pushing upper limits on any coupling between standard-model fields and the new light degrees of freedom generically predicted by these theories down to unnaturally small levels.

Fundamentals of differential beamforming

CERN Document Server

Benesty, Jacob; Pan, Chao

2016-01-01

This book provides a systematic study of the fundamental theory and methods of beamforming with differential microphone arrays (DMAs), or differential beamforming in short. It begins with a brief overview of differential beamforming and some popularly used DMA beampatterns such as the dipole, cardioid, hypercardioid, and supercardioid, before providing essential background knowledge on orthogonal functions and orthogonal polynomials, which form the basis of differential beamforming. From a physical perspective, a DMA of a given order is defined as an array that measures the differential acoustic pressure field of that order; such an array has a beampattern in the form of a polynomial whose degree is equal to the DMA order. Therefore, the fundamental and core problem of differential beamforming boils down to the design of beampatterns with orthogonal polynomials. But certain constraints also have to be considered so that the resulting beamformer does not seriously amplify the sensors’ self noise and the mism...

Pump-shaped dump optimal control reveals the nuclear reaction pathway of isomerization of a photoexcited cyanine dye.

Science.gov (United States)

Dietzek, Benjamin; Brüggemann, Ben; Pascher, Torbjörn; Yartsev, Arkady

2007-10-31

Using optimal control as a spectroscopic tool we decipher the details of the molecular dynamics of the essential multidimensional excited-state photoisomerization - a fundamental chemical reaction of key importance in biology. Two distinct nuclear motions are identified in addition to the overall bond-twisting motion: Initially, the reaction is dominated by motion perpendicular to the torsion coordinate. At later times, a second optically active vibration drives the system along the reaction path to the bottom of the excited-state potential. The time scales of the wavepacket motion on a different part of the excited-state potential are detailed by pump-shaped dump optimal control. This technique offers new means to control a chemical reaction far from the Franck-Condon point of absorption and to map details of excited-state reaction pathways revealing unique insights into the underlying reaction mechanism.

Classical mechanics Hamiltonian and Lagrangian formalism

CERN Document Server

Deriglazov, Alexei

2016-01-01

This account of the fundamentals of Hamiltonian mechanics also covers related topics such as integral invariants and the Noether theorem. With just the elementary mathematical methods used for exposition, the book is suitable for novices as well as graduates.

Quantum mechanics a comprehensive text for chemistry

CERN Document Server

Arora, Kishor

2010-01-01

This book contains 14 chapters. The text includes the inadequacy of classical mechanics and covers basic and fundamental concepts of quantum mechanics including concepts of transitional, vibration rotation and electronic energies, introduction to concepts of angular momenta, approximatemethods and their application concepts related to electron spin, symmetery concepts and quantum mechanics and ultimately the book features the theories of chemical bonding and use of softwares in quantum mechanics. the text of the book is presented in a lucid manner with ample examples and illustrations wherever

Testing Our Fundamental Assumptions

Science.gov (United States)

Kohler, Susanna

2016-06-01

Science is all about testing the things we take for granted including some of the most fundamental aspects of how we understand our universe. Is the speed of light in a vacuum the same for all photons regardless of their energy? Is the rest mass of a photon actually zero? A series of recent studies explore the possibility of using transient astrophysical sources for tests!Explaining Different Arrival TimesArtists illustration of a gamma-ray burst, another extragalactic transient, in a star-forming region. [NASA/Swift/Mary Pat Hrybyk-Keith and John Jones]Suppose you observe a distant transient astrophysical source like a gamma-ray burst, or a flare from an active nucleus and two photons of different energies arrive at your telescope at different times. This difference in arrival times could be due to several different factors, depending on how deeply you want to question some of our fundamental assumptions about physics:Intrinsic delayThe photons may simply have been emitted at two different times by the astrophysical source.Delay due to Lorentz invariance violationPerhaps the assumption that all massless particles (even two photons with different energies) move at the exact same velocity in a vacuum is incorrect.Special-relativistic delayMaybe there is a universal speed for massless particles, but the assumption that photons have zero rest mass is wrong. This, too, would cause photon velocities to be energy-dependent.Delay due to gravitational potentialPerhaps our understanding of the gravitational potential that the photons experience as they travel is incorrect, also causing different flight times for photons of different energies. This would mean that Einsteins equivalence principle, a fundamental tenet of general relativity (GR), is incorrect.If we now turn this problem around, then by measuring the arrival time delay between photons of different energies from various astrophysical sources the further away, the better we can provide constraints on these

Some fundamental aspects of fluctuations and coherence in charged-particle beams in storage rings

International Nuclear Information System (INIS)

Chattopadhyay, S.

1984-01-01

A conceptual survey and exposition is presented of some fundamental aspects of fluctuations and coherence, as well as the interplay between the two, in coasting charged-particle beams - both continuous and bunched - in storage rings. A detailed study is given of the spectral properties of the incoherent phase-space Schottky fluctuations, their propagation as waves in the beam, and the analytic complex coherent beam electromagnetic response or transfer function. The modification or distortion of these by collective interactions is examined in terms of simple regeneration mechanisms. Collective or coherent forces in the beam-storage-ring system are described by defining suitable impedance functions or propagators, and a brief discussion of the coherent collective modes and their stability is provided, including a general and rigorous description of the Nyquist stability criterion. The nature of the critical fluctuations near an instability threshold is explored. The concept of Landau damping and its connection with phase-mixing within the beam is outlined. The important connection between the incoherent fluctuations and the beam response, namely the Fluctuation-Dissipation relation, is revealed. A brief discussion is given of the information degrees of freedom, and effective temperature of the fluctuation signals. Appendices provide a short resume of some general aspects of various interactions in a charged-particle beam-environment system in a storage ring and a general introduction to kinetic theory as applied to particle beams. (orig.)

Uncertainty and Complementarity in Axiomatic Quantum Mechanics

Science.gov (United States)

Lahti, Pekka J.

1980-11-01

In this work an investigation of the uncertainty principle and the complementarity principle is carried through. A study of the physical content of these principles and their representation in the conventional Hilbert space formulation of quantum mechanics forms a natural starting point for this analysis. Thereafter is presented more general axiomatic framework for quantum mechanics, namely, a probability function formulation of the theory. In this general framework two extra axioms are stated, reflecting the ideas of the uncertainty principle and the complementarity principle, respectively. The quantal features of these axioms are explicated. The sufficiency of the state system guarantees that the observables satisfying the uncertainty principle are unbounded and noncompatible. The complementarity principle implies a non-Boolean proposition structure for the theory. Moreover, nonconstant complementary observables are always noncompatible. The uncertainty principle and the complementarity principle, as formulated in this work, are mutually independent. Some order is thus brought into the confused discussion about the interrelations of these two important principles. A comparison of the present formulations of the uncertainty principle and the complementarity principle with the Jauch formulation of the superposition principle is also given. The mutual independence of the three fundamental principles of the quantum theory is hereby revealed.

Study on fundamental mechanism of nuclear advanced robot. An analysis of fundamental motion with pliability for end-effector of advanced robot

International Nuclear Information System (INIS)

Ohki, Arahiko; Hirano, Sigeo; Yoshida, Tomoya.

1997-01-01

Most of present robots only perform works simulating human action, but hereafter, it is required to do advanced works smoothly with robots in place of men. Among the mechanisms of high performance robots, as one of the important components that do advanced action and adapt to diversified purposes, there is manipulator. The manipulator comprises arm and end effector. In the process of heightening robot performance hereafter, the reproduction of detailed action is the indispensable subject of research. The object of carrying out this research is to elucidate the possibility of giving the functions close to those of delicate human hands to end effector. First, the joints of human hands were measured, and based on these data, the equation for determining the change of angle in relation to the time of motion of respective joints was established. Further, the simulation of simple actions was carried out, and the concept of the mechanism model was built by analyzing the motion similar to human body. The structural difference in the joints of human and manipulator, the measurement of hands and the analysis of the motion of hand joints are reported. (K.I.)

Genome-wide maps of alkylation damage, repair, and mutagenesis in yeast reveal mechanisms of mutational heterogeneity.

Science.gov (United States)

Mao, Peng; Brown, Alexander J; Malc, Ewa P; Mieczkowski, Piotr A; Smerdon, Michael J; Roberts, Steven A; Wyrick, John J

2017-10-01

DNA base damage is an important contributor to genome instability, but how the formation and repair of these lesions is affected by the genomic landscape and contributes to mutagenesis is unknown. Here, we describe genome-wide maps of DNA base damage, repair, and mutagenesis at single nucleotide resolution in yeast treated with the alkylating agent methyl methanesulfonate (MMS). Analysis of these maps revealed that base excision repair (BER) of alkylation damage is significantly modulated by chromatin, with faster repair in nucleosome-depleted regions, and slower repair and higher mutation density within strongly positioned nucleosomes. Both the translational and rotational settings of lesions within nucleosomes significantly influence BER efficiency; moreover, this effect is asymmetric relative to the nucleosome dyad axis and is regulated by histone modifications. Our data also indicate that MMS-induced mutations at adenine nucleotides are significantly enriched on the nontranscribed strand (NTS) of yeast genes, particularly in BER-deficient strains, due to higher damage formation on the NTS and transcription-coupled repair of the transcribed strand (TS). These findings reveal the influence of chromatin on repair and mutagenesis of base lesions on a genome-wide scale and suggest a novel mechanism for transcription-associated mutation asymmetry, which is frequently observed in human cancers. © 2017 Mao et al.; Published by Cold Spring Harbor Laboratory Press.

Fundamental aspects on ion-beam surface modification: defect production and migration processes

International Nuclear Information System (INIS)

Rehn, L.E.; Averback, R.S.; Okamoto, P.R.

1984-09-01

Ion-beam modification of metals is generating increasing scientific interest not only because it has exciting technological potential, but also because it has raised fundamental questions concerning radiation-induced diffusion processes. In addition to the implanted species, several defect production and migration mechanisms contribute to changes in the near-surface composition of an alloy during ion bombardment, e.g., atoms exchange positions via displacements and replacement sequences; preferential sputtering effects arise; radiation-enhanced diffusion and radiation-induced segregation occur. The latter two defect migration mechanisms are of particular significance since they can alter the composition to depths which are much greater than the implanted ion range. By altering various parameters such as irradiation temperature, ion mass, energy, and current density, and initial alloying distributions, a rich variety of near-surface composition profiles can be created. We have utilized changes in ion mass and energy, and irradiation temperature to distinguish defect production from defect migration effects. Experimental results are presented which provide a guide to the relative efficiencies of different mechanisms under various irradiation conditions. 46 references

Mechanics of fluid flow

CERN Document Server

Basniev, Kaplan S; Chilingar, George V 0

2012-01-01

The mechanics of fluid flow is a fundamental engineering discipline explaining both natural phenomena and human-induced processes, and a thorough understanding of it is central to the operations of the oil and gas industry.  This book, written by some of the world's best-known and respected petroleum engineers, covers the concepts, theories, and applications of the mechanics of fluid flow for the veteran engineer working in the field and the student, alike.  It is a must-have for any engineer working in the oil and gas industry.

Comparative proteomic and metabolomic analysis reveal the antiosteoporotic molecular mechanism of icariin from Epimedium brevicornu maxim.

Science.gov (United States)

Xue, Liming; Jiang, Yiping; Han, Ting; Zhang, Naidan; Qin, Luping; Xin, Hailiang; Zhang, Qiaoyan

2016-11-04

Icariin, a principal flavonoid glycoside of Epimedium brevicornu Maxim, has been widely proved to possess antiosteoporotic activity with promoting bone formation and decreasing bone resorption. However, the involving mechanisms remain unclear. To clear a global insight of signal pathways involved in anti-osteoporotic mechanism of icariin at proteins and metabolites level by integrating the proteomics and NMR metabonomics, in a systems biology approach. Mice were divided into sham, OVX model and icariin-treated OVX group, after 90 days treatment, difference gel electrophoresis combined with MALDI-TOF/TOF proteomics analysis on bone femur and serum metabolomics were carried out for monitor intracellular processes and elucidate anti-osteoporotic mechanism of icariin. Osteoblast and osteoclast were applied to evaluate the potential signal pathways. Twenty three proteins in bone femur, and 8 metabolites in serum, were significantly altered and identified, involving in bone remodeling, energy metabolism, cytoskeleton, lipid metabolism, MAPK signaling, Ca 2+ signaling et, al. Furthermore, animal experiment show icariin could enhance the BMD and BMC, decrease CTX-I level in ovariectomized mice. The mitochondrial membrane potential and the intracellular ATP levels were increased significantly, and the cytoskeleton were improved in icariin-treatment osteoblast and osteoclast. Icariin also increased mRNA expression of Runx2 and osterix of OB, decreased CTR and CAII mRNA expression and protein expression of P38 and JNK. However, icariin did not reveal any inhibition of the collagenolytic activity of cathepsin K, mRNA expression of MMP-9 and protein expression of ERK in osteoclast. we consider icariin as multi-targeting compounds for treating with osteoporosis, involve initiating osteoblastogenesis, inhibiting adipogenesis, and preventing osteoclast differentiation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Are fundamental constants really constant

International Nuclear Information System (INIS)

Norman, E.B.

1986-01-01

Reasons for suspecting that fundamental constants might change with time are reviewed. Possible consequences of such variations are examined. The present status of experimental tests of these ideas is discussed

Quantum-mechanical computers and uncomputability

International Nuclear Information System (INIS)

Lloyd, S.

1993-01-01

The time evolution operator for any quantum-mechanical computer is diagonalizable, but to obtain the diagonal decomposition of a program state of the computer is as hard as actually performing the computation corresponding to the program. In particular, if a quantum-mechanical system is capable of universal computation, then the diagonal decomposition of program states is uncomputable. As a result, in a universe in which local variables support universal computation, a quantum-mechanical theory for that universe that supplies its spectrum cannot supply the spectral decomposition of the computational variables. A ''theory of everything'' can be simultaneously correct and fundamentally incomplete

Religious Fundamentalism/Religious Modernism: Conceptual Adversaries or Ambivalent Phenomena?

Directory of Open Access Journals (Sweden)

D. GOLOVUSHKIN

2015-02-01

Full Text Available Both religious modernism and religious fundamentalism appeared as problems in academic and theological literature at the beginning of the 20th century. They came about as the result of the dynamic development of modernistic ideology in Russia, the United States, Western Europe and the Islamic world. Today, the concepts of religious modernism and religious fundamentalism are widely used to describe religious processes and phenomena which are the result of interaction between religion (as a dynamic spiritual and social subsystem and society - as a social system experiencing evolution. The concept of religious modernism is traditionally associated with religious renewal, the contemporary world, and innovation. Fundamentalism, on the contrary, is an ideological commitment to the “roots and origins” of religion. Under the aegis of fundamentalism, any religious idea, value or concept has a right to exist. Religious Studies, during the course of time and the production of ever new material, encountered a serious theoretic-methodological problem: How can various religious movements and religious traditions be organized into groups since some of them combine elements of religious modernism and of religious fundamentalism? Already at the end of the nineteen-eighties, the well-established view defining “fundamentalism-modernism” as contrary positions had to be rethought. Studies dating from the nineteen-nineties and the beginning of the new millennium concentrated on noting the social origins and the political character of these phenomena. They demonstrated that neither fundamentalism nor modernism present the whole picture. The lines dividing them are so blurred, that they become confl uent. Consequently, the author concludes that religious fundamentalism and religious modernism are ambivalent phenomena, which can, on occasion, interact with each other.

Subsurface damage mechanism of high speed grinding process in single crystal silicon revealed by atomistic simulations

International Nuclear Information System (INIS)

Li, Jia; Fang, Qihong; Zhang, Liangchi; Liu, Youwen

2015-01-01

stress status. The dislocation nucleation and motion induced plastic deformation during grinding process can better reveal subsurface damage mechanism considering to stress and temperature acting on the dislocations

DOE Fundamentals Handbook: Classical Physics

International Nuclear Information System (INIS)

1992-06-01

The Classical Physics Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of physical forces and their properties. The handbook includes information on the units used to measure physical properties; vectors, and how they are used to show the net effect of various forces; Newton's Laws of motion, and how to use these laws in force and motion applications; and the concepts of energy, work, and power, and how to measure and calculate the energy involved in various applications. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility systems and equipment

Fundamentals of electronic systems design

CERN Document Server

Lienig, Jens

2017-01-01

This textbook covers the design of electronic systems from the ground up, from drawing and CAD essentials to recycling requirements. Chapter by chapter, it deals with the challenges any modern system designer faces: the design process and its fundamentals, such as technical drawings and CAD, electronic system levels, assembly and packaging issues and appliance protection classes, reliability analysis, thermal management and cooling, electromagnetic compatibility (EMC), all the way to recycling requirements and environmental-friendly design principles. Enables readers to face various challenges of designing electronic systems, including coverage from various engineering disciplines; Written to be accessible to readers of varying backgrounds; Uses illustrations extensively to reinforce fundamental concepts; Organized to follow essential design process, although chapters are self-contained and can be read in any order.

Mechanics, waves and thermodynamics an example-based approach

CERN Document Server

Jain, Sudhir Ranjan

2016-01-01

The principles of classical physics, though superseded in specific fields by such theories as quantum mechanics and general relativity, are still of great importance in a broad range of applications. The book presents fundamental concepts of classical physics in a coherent and logical manner. It discusses important topics including the mechanics of a single particle, kinetic theory, oscillations and waves. Topics including the kinetic theory of gases, thermodynamics and statistical mechanics are discussed, which are normally not present in the books on classical physics. The fundamental concepts of energy, momentum, mass and entropy are explained with examples. Discussion on concepts of thermodynamics is presented along with the simplified explanation on Caratheodory's axioms. It covers chapters on wave motion and statistical physics, useful for the graduate students. Each concept is supported with real-life applications on several concepts including impulse and collision, Bernoulli's equation, and friction.

Fundamental measure theory for hard-sphere mixtures: a review

International Nuclear Information System (INIS)

Roth, Roland

2010-01-01

Hard-sphere systems are one of the fundamental model systems of statistical physics and represent an important reference system for molecular or colloidal systems with soft repulsive or attractive interactions in addition to hard-core repulsion at short distances. Density functional theory for classical systems, as one of the core theoretical approaches of statistical physics of fluids and solids, has to be able to treat such an important system successfully and accurately. Fundamental measure theory is up to date the most successful and most accurate density functional theory for hard-sphere mixtures. Since its introduction fundamental measure theory has been applied to many problems, tested against computer simulations, and further developed in many respects. The literature on fundamental measure theory is already large and is growing fast. This review aims to provide a starting point for readers new to fundamental measure theory and an overview of important developments. (topical review)

Structural and functional studies of the modulator NS9283 reveal agonist-like mechanism of action at α4β2 nicotinic acetylcholine receptors

DEFF Research Database (Denmark)

Olsen, Jeppe A; Ahring, Philip K; Kastrup, Jette Sandholm Jensen

2014-01-01

Modulation of Cys loop receptor ion channels is a proven drug discovery strategy, but many underlying mechanisms of the mode of action are poorly understood. We report the x-ray structure of the acetylcholine-binding protein from Lymnaea stagnalis with NS9283, a stoichiometry selective positive...... on efficacy. The shared modulatory profile along with a binding site located in an extracellular subunit interface suggest that modulation via an agonist-like mechanism may be a common mechanism of action that potentially could apply to Cys loop receptors beyond the α4β2 nAChRs....... modulator that targets the α4-α4 interface of α4β2 nicotinic acetylcholine receptors (nAChRs). Together with homology modeling, mutational data, quantum mechanical calculations, and pharmacological studies on α4β2 nAChRs, the structure reveals a modulator binding mode that overlaps the α4-α4 interface...

Mechanical alloying nanotechnology, materials science and powder metallurgy

CERN Document Server

El-Eskandarany, M Sherif

2015-01-01

This book is a detailed introduction to mechanical alloying, offering guidelines on the necessary equipment and facilities needed to carry out the process and giving a fundamental background to the reactions taking place. El-Eskandarany, a leading authority on mechanical alloying, discusses the mechanism of powder consolidations using different powder compaction processes. A new chapter will also be included on thermal, mechanically-induced and electrical discharge-assisted mechanical milling. Fully updated to cover recent developments in the field, this second edition also introduces new a

Marketing fundamentals.

Science.gov (United States)

Redmond, W H

2001-01-01

This chapter outlines current marketing practice from a managerial perspective. The role of marketing within an organization is discussed in relation to efficiency and adaptation to changing environments. Fundamental terms and concepts are presented in an applied context. The implementation of marketing plans is organized around the four P's of marketing: product (or service), promotion (including advertising), place of delivery, and pricing. These are the tools with which marketers seek to better serve their clients and form the basis for competing with other organizations. Basic concepts of strategic relationship management are outlined. Lastly, alternate viewpoints on the role of advertising in healthcare markets are examined.

Bohm's mechanics. An elementary introduction to the deterministic interpretation of quantum mechanics. 2. enl. and rev. ed.

International Nuclear Information System (INIS)

Passon, Oliver

2010-01-01

Bohm's mechanics belong to the alternative formulations of quantum mechanics, deviates in their knowledge-theoretical implications however radially from the usual Copenhagen interpretation. Their importance lies by this above all in the region of fundamental questions and the interpretation of quantum mechanics, because they allow yet a solution of the measurement problem discussed since decades controversy. Simultaneously all predictions of usual quantum mechanics can be reproduced. Even though on the German-language textbook market hitherto an elementary introduction to this topic lacked. New in the second edition is a short draft of the relativistic and quantum-field theoretical generalizations.

Mechanical properties of ultra thin metallic films revealed by synchrotron techniques

Energy Technology Data Exchange (ETDEWEB)

Gruber, Patric Alfons

2007-07-20

A prerequisite for the study of the scaling behavior of mechanical properties of ultra thin films is a suitable testing technique. Therefore synchrotron-based in situ testing techniques were developed and optimized in order to characterize the stress evolution in ultra thin metallic films on compliant polymer substrates during isothermal tensile tests. Experimental procedures for polycrystalline as well as single crystalline films were established. These techniques were used to systematically investigate the influence of microstructure, film thickness (20 to 1000 nm) and temperature (-150 to 200 C) on the mechanical properties. Passivated and unpassivated Au and Cu films as well as single crystalline Au films on polyimide substrates were tested. Special care was also dedicated to the microstructural characterization of the samples which was very important for the correct interpretation of the results of the mechanical tests. Down to a film thickness of about 100 to 200 nm the yield strength increased for all film systems (passivated and unpassivated) and microstructures (polycrystalline and singlecrystalline). The influence of different interfaces was smaller than expected. This could be explained by a dislocation source model based on the nucleation of perfect dislocations. For polycrystalline films the film thickness as well as the grain size distribution had to be considered. For smaller film thicknesses the increase in flow stress was weaker and the deformation behavior changed because the nucleation of perfect dislocations became unfavorable. Instead, the film materials used alternative mechanisms to relieve the high stresses. For regular and homogeneous deformation the total strain was accommodated by the nucleation and motion of partial dislocations. If the deformation was localized due to initial cracks in a brittle interlayer or local delamination, dislocation plasticity was not effective enough to relieve the stress concentration and the films showed

SU (2) with fundamental fermions and scalars

DEFF Research Database (Denmark)

Hansen, Martin; Janowski, Tadeusz; Pica, Claudio

2018-01-01

We present preliminary results on the lattice simulation of an SU(2) gauge theory with two fermion flavors and one strongly interacting scalar field, all in the fundamental representation of SU(2). The motivation for this study comes from the recent proposal of "fundamental" partial compositeness...... the properties of light meson resonances previously obtained for the SU(2) model. Preprint: CP3-Origins-2017-047 DNRF90...

Deep RNA sequencing reveals dynamic regulation of myocardial noncoding RNAs in failing human heart and remodeling with mechanical circulatory support.

Science.gov (United States)

Yang, Kai-Chien; Yamada, Kathryn A; Patel, Akshar Y; Topkara, Veli K; George, Isaac; Cheema, Faisal H; Ewald, Gregory A; Mann, Douglas L; Nerbonne, Jeanne M

2014-03-04

Microarrays have been used extensively to profile transcriptome remodeling in failing human heart, although the genomic coverage provided is limited and fails to provide a detailed picture of the myocardial transcriptome landscape. Here, we describe sequencing-based transcriptome profiling, providing comprehensive analysis of myocardial mRNA, microRNA (miRNA), and long noncoding RNA (lncRNA) expression in failing human heart before and after mechanical support with a left ventricular (LV) assist device (LVAD). Deep sequencing of RNA isolated from paired nonischemic (NICM; n=8) and ischemic (ICM; n=8) human failing LV samples collected before and after LVAD and from nonfailing human LV (n=8) was conducted. These analyses revealed high abundance of mRNA (37%) and lncRNA (71%) of mitochondrial origin. miRNASeq revealed 160 and 147 differentially expressed miRNAs in ICM and NICM, respectively, compared with nonfailing LV. Among these, only 2 (ICM) and 5 (NICM) miRNAs are normalized with LVAD. RNASeq detected 18 480, including 113 novel, lncRNAs in human LV. Among the 679 (ICM) and 570 (NICM) lncRNAs differentially expressed with heart failure, ≈10% are improved or normalized with LVAD. In addition, the expression signature of lncRNAs, but not miRNAs or mRNAs, distinguishes ICM from NICM. Further analysis suggests that cis-gene regulation represents a major mechanism of action of human cardiac lncRNAs. The myocardial transcriptome is dynamically regulated in advanced heart failure and after LVAD support. The expression profiles of lncRNAs, but not mRNAs or miRNAs, can discriminate failing hearts of different pathologies and are markedly altered in response to LVAD support. These results suggest an important role for lncRNAs in the pathogenesis of heart failure and in reverse remodeling observed with mechanical support.

Chapter 4. Fundamental mechanisms of the low temperature plastic deformation of metals

International Nuclear Information System (INIS)

Fouquet, J. de

1976-01-01

The influence of microstructure, grain boundaries, and strain hardening, on the low temperature plasticity of polycristals is studied. The experimental data on flow stress, work hardening, temperature and strain rate effects, alloying elements and grain size effect are firstly considered, on a macroscopic scale. The mechanisms of the low temperature plastic deformation, and the strain-stress relations are then described in terms of slip modes, mobility, configuration and distributions and interactions of dislocations [fr

Potent neutralization of hepatitis A virus reveals a receptor mimic mechanism and the receptor recognition site.

Science.gov (United States)

Wang, Xiangxi; Zhu, Ling; Dang, Minghao; Hu, Zhongyu; Gao, Qiang; Yuan, Shuai; Sun, Yao; Zhang, Bo; Ren, Jingshan; Kotecha, Abhay; Walter, Thomas S; Wang, Junzhi; Fry, Elizabeth E; Stuart, David I; Rao, Zihe

2017-01-24

Hepatitis A virus (HAV) infects ∼1.4 million people annually and, although there is a vaccine, there are no licensed therapeutic drugs. HAV is unusually stable (making disinfection problematic) and little is known of how it enters cells and releases its RNA. Here we report a potent HAV-specific monoclonal antibody, R10, which neutralizes HAV infection by blocking attachment to the host cell. High-resolution cryo-EM structures of HAV full and empty particles and of the complex of HAV with R10 Fab reveal the atomic details of antibody binding and point to a receptor recognition site at the pentamer interface. These results, together with our observation that the R10 Fab destabilizes the capsid, suggest the use of a receptor mimic mechanism to neutralize virus infection, providing new opportunities for therapeutic intervention.

Assessing recall, conceptualization, and transfer capabilities of novice biochemistry students' across learning style preferences as revealed by self-explanations

Science.gov (United States)

Hilsenbeck-Fajardo, Jacqueline L.

2009-08-01

The research described herein is a multi-dimensional attempt to measure student's abilities to recall, conceptualize, and transfer fundamental and dynamic protein structure concepts as revealed by their own diagrammatic (pictorial) representations and written self-explanations. A total of 120 participants enrolled in a 'Fundamentals of Biochemistry' course contributed to this mixed-methodological study. The population of interest consisted primarily of pre-nursing and sport and exercise science majors. This course is typically associated with a high (researcher with an ideal context in which to apply novel transfer assessment strategies. In the past, students within this population have reported very little chemistry background. In the following study, student-generated diagrammatic representations and written explanations were coded thematically using a highly objective rubric that was designed specifically for this study. Responses provided by the students were characterized on the macroscopic, microscopic, molecular-level, and integrated scales. Recall knowledge gain (i.e., knowledge that was gained through multiple-choice questioning techniques) was quantitatively correlated to learning style preferences (i.e., high-object, low-object, and non-object). Quantitative measures revealed that participants tended toward an object (i.e., snapshot) -based visualization preference, a potentially limiting factor in their desire to consider dynamic properties of fundamental biochemical contexts such as heat-induced protein denaturation. When knowledge transfer was carefully assessed within the predefined context, numerous misconceptions pertaining to the fundamental and dynamic nature of protein structure were revealed. Misconceptions tended to increase as the transfer model shifted away from the context presented in the original learning material. Ultimately, a fundamentally new, novel, and unique measure of knowledge transfer was developed as a main result of this study

Accounting Fundamentals for Non-Accountants

Science.gov (United States)

The purpose of this module is to provide an introduction and overview of accounting fundamentals for non-accountants. The module also covers important topics such as communication, internal controls, documentation and recordkeeping.

The Quantitative and Qualitative Status of Fundamental Movement ...

African Journals Online (AJOL)

South African Journal for Research in Sport, Physical Education and Recreation ... The Bruininks-Oseretsky Test of Motor Proficiency 2 (BOT-2), was used to assess six fundamental movement skills quantitatively, and the Fundamental Movement Pattern Assessment Instrument (FMPAI), was applied to analyse the same ...

Notes on continuum mechanics

CERN Document Server

Chaves, Eduardo W V

2013-01-01

This publication is aimed at students, teachers, and researchers of Continuum Mechanics and focused extensively on stating and developing Initial Boundary Value equations used to solve physical problems. With respect to notation, the tensorial, indicial and Voigt notations have been used indiscriminately.   The book is divided into twelve chapters with the following topics: Tensors, Continuum Kinematics, Stress, The Objectivity of Tensors, The Fundamental Equations of Continuum Mechanics, An Introduction to Constitutive Equations, Linear Elasticity, Hyperelasticity, Plasticity (small and large deformations), Thermoelasticity (small and large deformations), Damage Mechanics (small and large deformations), and An Introduction to Fluids. Moreover, the text is supplemented with over 280 figures, over 100 solved problems, and 130 references.

Statistical mechanics principles and selected applications

CERN Document Server

Hill, Terrell L

1956-01-01

""Excellent … a welcome addition to the literature on the subject."" - ScienceBefore the publication of this standard, oft-cited book, there were few if any statistical-mechanics texts that incorporated reviews of both fundamental principles and recent developments in the field.In this volume, Professor Hill offers just such a dual presentation - a useful account of basic theory and of its applications, made accessible in a comprehensive format. The book opens with concise, unusually clear introductory chapters on classical statistical mechanics, quantum statistical mechanics and the relatio

Genome-Wide RNAi Ionomics Screen Reveals New Genes and Regulation of Human Trace Element Metabolism

Science.gov (United States)

Malinouski, Mikalai; Hasan, Nesrin M.; Zhang, Yan; Seravalli, Javier; Lin, Jie; Avanesov, Andrei; Lutsenko, Svetlana; Gladyshev, Vadim N.

2017-01-01

Trace elements are essential for human metabolism and dysregulation of their homeostasis is associated with numerous disorders. Here we characterize mechanisms that regulate trace elements in human cells by designing and performing a genome-wide high-throughput siRNA/ionomics screen, and examining top hits in cellular and biochemical assays. The screen reveals high stability of the ionomes, especially the zinc ionome, and yields known regulators and novel candidates. We further uncover fundamental differences in the regulation of different trace elements. Specifically, selenium levels are controlled through the selenocysteine machinery and expression of abundant selenoproteins; copper balance is affected by lipid metabolism and requires machinery involved in protein trafficking and posttranslational modifications; and the iron levels are influenced by iron import and expression of the iron/heme-containing enzymes. Our approach can be applied to a variety of disease models and/or nutritional conditions, and the generated dataset opens new directions for studies of human trace element metabolism. PMID:24522796

Proteomic Analysis of Lysine Acetylation Sites in Rat Tissues Reveals Organ Specificity and Subcellular Patterns

Directory of Open Access Journals (Sweden)

Alicia Lundby

2012-08-01

Full Text Available Lysine acetylation is a major posttranslational modification involved in a broad array of physiological functions. Here, we provide an organ-wide map of lysine acetylation sites from 16 rat tissues analyzed by high-resolution tandem mass spectrometry. We quantify 15,474 modification sites on 4,541 proteins and provide the data set as a web-based database. We demonstrate that lysine acetylation displays site-specific sequence motifs that diverge between cellular compartments, with a significant fraction of nuclear sites conforming to the consensus motifs G-AcK and AcK-P. Our data set reveals that the subcellular acetylation distribution is tissue-type dependent and that acetylation targets tissue-specific pathways involved in fundamental physiological processes. We compare lysine acetylation patterns for rat as well as human skeletal muscle biopsies and demonstrate its general involvement in muscle contraction. Furthermore, we illustrate that acetylation of fructose-bisphosphate aldolase and glycerol-3-phosphate dehydrogenase serves as a cellular mechanism to switch off enzymatic activity.

Mechanical Resonators for Quantum Optomechanics Experiments at Room Temperature.

Science.gov (United States)

Norte, R A; Moura, J P; Gröblacher, S

2016-04-08

All quantum optomechanics experiments to date operate at cryogenic temperatures, imposing severe technical challenges and fundamental constraints. Here, we present a novel design of on-chip mechanical resonators which exhibit fundamental modes with frequencies f and mechanical quality factors Q_{m} sufficient to enter the optomechanical quantum regime at room temperature. We overcome previous limitations by designing ultrathin, high-stress silicon nitride (Si_{3}N_{4}) membranes, with tensile stress in the resonators' clamps close to the ultimate yield strength of the material. By patterning a photonic crystal on the SiN membranes, we observe reflectivities greater than 99%. These on-chip resonators have remarkably low mechanical dissipation, with Q_{m}∼10^{8}, while at the same time exhibiting large reflectivities. This makes them a unique platform for experiments towards the observation of massive quantum behavior at room temperature.

An SEU tolerant memory cell derived from fundamental studies of SEU mechanisms in SRAM

International Nuclear Information System (INIS)

Weaver, H.T.; Axness, C.L.; McBrayer, J.D.; Browning, J.S.; Fu, J.S.; Ochoa, A. Jr.; Koga, R.

1987-01-01

A new single event upset (SEU) hardening concept, an LRAM cell, is demonstrated theoretically and experimentally. Decoupling resistors in the LRAM are used only to protect against the short n-channel transient; longer persisting pulses are reduced in magnitude by a voltage divider, a basically new concept for SEU protection. In such a design, smaller resistors provide SEU tolerance, allowing higher performance, hardened memories. As basis for the LRAM idea, techniques were developed to measure time constants for ion induced voltage transients in conventional static random access memories, SRAM. Time constants of 0.8 and 6.3 nsec were measured for transients following strikes at the n- and p-channel drains, respectively - primary areas of SEU sensitivity. These data are the first transient time measurements on full memory chips and the large difference is fundamental to the LRAM concept. Test structures of the new design exhibit equivalent SEU tolerance with resistors 5-to-10 times smaller than currently used in SRAM. Our advanced transport-plus-circuit numerical simulations of the SEU process predicted this result and account for the LRAM experiments, as well as a variety of experiments on conventional SRAM

An Ultraviolet Chiral Theory of the Top for the Fundamental Composite (Goldstone) Higgs

DEFF Research Database (Denmark)

Cacciapaglia, Giacomo; Sannino, Francesco

2016-01-01

We introduce a scalar-less anomaly free chiral gauge theory that serves as natural ultraviolet completion of models of fundamental composite (Goldstone) Higgs dynamics. The new theory is able to generate the top mass and furthermore features a built-in protection mechanism that naturally suppresses...... the bottom mass. At low energies the theory predicts new fractionally charged fermions, and a number of four-fermion operators that, besides being relevant for the generation of the top mass, also lead to an intriguing phenomenology for the new states predicted by the theory....

An ultraviolet chiral theory of the top for the fundamental composite (Goldstone) Higgs

Energy Technology Data Exchange (ETDEWEB)

Cacciapaglia, Giacomo, E-mail: g.cacciapaglia@ipnl.in2p3.fr [Univ Lyon, Université Lyon 1, CNRS/IN2P3, IPNL, 4 rue Enrico Fermi, F-69622 Villeurbanne Cedex (France); Sannino, Francesco, E-mail: sannino@cp3.dias.sdu.dk [CP" 3-Origins and the Danish IAS, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark)

2016-04-10

We introduce a scalar-less anomaly free chiral gauge theory that serves as natural ultraviolet completion of models of fundamental composite (Goldstone) Higgs dynamics. The new theory is able to generate the top mass and furthermore features a built-in protection mechanism that naturally suppresses the bottom mass. At low energies the theory predicts new fractionally charged fermions, and a number of four-fermion operators that, besides being relevant for the generation of the top mass, also lead to an intriguing phenomenology for the new states predicted by the theory.

Fundamental limitations of non-thermal plasma processing for internal combustion engine NOx control

International Nuclear Information System (INIS)

Penetrante, B.M.

1993-01-01

This paper discusses the physics and chemistry of non-thermal plasma processing for post-combustion NO x control in internal combustion engines. A comparison of electron beam and electrical discharge processing is made regarding their power consumption, radical production, NO x removal mechanisms, and by product formation. Can non-thermal deNO x operate efficiently without additives or catalysts? How much electrical power does it cost to operate? What are the by-products of the process? This paper addresses these fundamental issues based on an analysis of the electron-molecule processes and chemical kinetics

Computational contact and impact mechanics fundamentals of modeling interfacial phenomena in nonlinear finite element analysis

CERN Document Server

Laursen, Tod A

2003-01-01

This book comprehensively treats the formulation and finite element approximation of contact and impact problems in nonlinear mechanics. Intended for students, researchers and practitioners interested in numerical solid and structural analysis, as well as for engineers and scientists dealing with technologies in which tribological response must be characterized, the book includes an introductory but detailed overview of nonlinear finite element formulations before dealing with contact and impact specifically. Topics encompassed include the continuum mechanics, mathematical structure, variational framework, and finite element implementations associated with contact/impact interaction. Additionally, important and currently emerging research topics in computational contact mechanics are introduced, encompassing such topics as tribological complexity, conservative treatment of inelastic impact interaction, and novel spatial discretization strategies.