Better exercise adherence after treatment for cancer (BEAT Cancer) study: Rationale, design, and methods

PubMed Central

Rogers, Laura Q.; McAuley, Edward; Anton, Philip M.; Courneya, Kerry S.; Vicari, Sandra; Hopkins-Price, Patricia; Verhulst, Steven; Mocharnuk, Robert; Hoelzer, Karen

2011-01-01

Most breast cancer survivors do not engage in regular physical activity. Our physical activity behavior change intervention for breast cancer survivors significantly improved physical activity and health outcomes post-intervention during a pilot, feasibility study. Testing in additional sites with a larger sample and longer follow-up is warranted to confirm program effectiveness short and longer term. Importantly, the pilot intervention resulted in changes in physical activity and social cognitive theory constructs, enhancing our potential for testing mechanisms mediating physical activity behavior change. Here, we report the rationale, design, and methods for a two-site, randomized controlled trial comparing the effects of the BEAT Cancer physical activity behavior change intervention to usual care on short and longer term physical activity adherence among breast cancer survivors. Secondary aims include examining social cognitive theory mechanisms of physical activity behavior change and health benefits of the intervention. Study recruitment goal is 256 breast cancer survivors with a history of ductal carcinoma in situ or Stage I, II, or IIIA disease who have completed primary cancer treatment. Outcome measures are obtained at baseline, 3 months (i.e., immediately post-intervention), 6 months, and 12 months and include physical activity, psychosocial factors, fatigue, sleep quality, lower extremity joint dysfunction, cardiorespiratory fitness, muscle strength, and waist-to-hip ratio. Confirming behavior change effectiveness, health effects, and underlying mechanisms of physical activity behavior change interventions will facilitate translation to community settings for improving the health and well-being of breast cancer survivors. PMID:21983625

AAPT/NSTA High School Physics Examination.

ERIC Educational Resources Information Center

Nelson, James

1983-01-01

Discusses development of the American Association of Physics Teachers and National Science Teachers Association (AAPT/NSTA) high school physics examination. Includes sample examination questions and distribution of topics: mechanics (30 percent), waves/optics/sound (20 percent), heat/kinetic theory (10 percent), electricity/magnetism (25 percent),…

Study Modules for Calculus-Based General Physics. [Includes Modules 11-14: Collisions; Equilibrium of Rigid Bodies; Rotational Dynamics; and Fluid Mechanics].

ERIC Educational Resources Information Center

Fuller, Robert G., Ed.; And Others

This is part of a series of 42 Calculus Based Physics (CBP) modules totaling about 1,000 pages. The modules include study guides, practice tests, and mastery tests for a full-year individualized course in calculus-based physics based on the Personalized System of Instruction (PSI). The units are not intended to be used without outside materials;…

Is classical mechanics a prerequisite for learning physics of the 20th century?

NASA Astrophysics Data System (ADS)

Walwema, Godfrey B.; French, Debbie A.; Verley, Jim D.; Burrows, Andrea C.

2016-11-01

Physics of the 20th century has contributed significantly to modern technology, and yet many physics students are never availed the opportunity to study it as part of the curriculum. One of the possible reasons why it is not taught in high school and introductory physics courses could be because curriculum designers believe that students need a solid background in classical mechanics and calculus in order to study physics of the 20th century such as the photoelectric effect, special and general relativity, the uncertainty principle, etc. This presumption may not be justifiable or valid. The authors of this paper contend that teaching physics of the 20th century aids students in relating physics to modern technology and the real world, making studying physics exciting. In this study, the authors correlated scores for matched questions in the Mechanics Baseline Test and a physics of the 20th century test in order to examine the trend of the scores. The participants included undergraduate students attending an introductory algebra-based physics course with no intention of taking physics at a higher level. The analysis of the scores showed no significant correlation for any of the matched pairs of questions. The purpose of this article is to recommend that even without a solid background in classical mechanics, teachers can introduce physics of the 20th century to their students for increased interest.

A Non-Intuitionist's Approach To The Interpretation Problem Of Quantum Mechanics

NASA Astrophysics Data System (ADS)

Grelland, Hans Herlof

2005-02-01

A philosophy of physics called "linguistic empiricism" is presented and applied to the interpretation problem of quantum mechanics. This philosophical position is based on the works of Jacques Derrida. The main propositions are (i) that meaning, included the meaning attached to observations, are language-dependent and (ii) that mathematics in physics should be considered as a proper language, not necessary translatable to a more basic language of intuition and immediate experience. This has fundamental implications for quantum mechanics, which is a mathematically coherent and consistent theory; its interpretation problem is associated with its lack of physical images expressible in ordinary language.

The Effect of Nanocopper Additions in a Urea-Formaldehyde Adhesive on the Physical and Mechanical Properties of Particleboard Manufactured from Date Palm Waste

NASA Astrophysics Data System (ADS)

Rangavar, H.; Hoseiny fard, M. S.

2015-03-01

The effect of addition of copper nanoparticles to a urea-formaldehyde (UF) adhesive on the physical and mechanical properties of particleboards manufactured from date palm waste (DPW) was investigated. The variable factors in the study included copper nanoparticles in amounts of 6 and 8 wt.% of the dry mass of wood, pressing durations of 5 and 6 min, and pressing temperatures of 150 and 160°C. The physical and mechanical properties of manufactured boards were measured according to EN standards. The results showed that the addition of copper nanoparticles to the UF adhesive considerably improved the physical and mechanical properties of the boards and shortened the pressing duration. The boards manufactured with 6 wt.% copper nanoparticles in a dry mass of wood mixed with the adhesive and pressed at a temperature of 160°C for 5 min had mechanical properties exceeding the EN312-2 standard levels.

Application of wave mechanics theory to fluid dynamics problems: Fundamentals

NASA Technical Reports Server (NTRS)

Krzywoblocki, M. Z. V.

1974-01-01

The application of the basic formalistic elements of wave mechanics theory is discussed. The theory is used to describe the physical phenomena on the microscopic level, the fluid dynamics of gases and liquids, and the analysis of physical phenomena on the macroscopic (visually observable) level. The practical advantages of relating the two fields of wave mechanics and fluid mechanics through the use of the Schroedinger equation constitute the approach to this relationship. Some of the subjects include: (1) fundamental aspects of wave mechanics theory, (2) laminarity of flow, (3) velocity potential, (4) disturbances in fluids, (5) introductory elements of the bifurcation theory, and (6) physiological aspects in fluid dynamics.

Purposes of Physical Education - Today and Tomorrow.

ERIC Educational Resources Information Center

LaPlante, Marilyn

The emphasis in physical education appears to be changing toward a more humanistic education to counteract a dehumanizing trend with the emphasis on mechanization, efficiency, and technological innovation. This paper includes the results from a small survey of physical educators representing five groups: (1) curriculum theorists, (2) researchers,…

NASA Tech Briefs, July 1996. Volume 20, No. 7

NASA Technical Reports Server (NTRS)

1996-01-01

Topics covered include: Mechanical Components; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports

NASA Tech Briefs, October 1997. Volume 21, No. 10

NASA Technical Reports Server (NTRS)

1997-01-01

Topics covered include: Sensors/Imaging; Mechanical Components; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Software; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports.

Mechanisms of action in mindfulness-based cognitive therapy (MBCT) and mindfulness-based stress reduction (MBSR) in people with physical and/or psychological conditions: A systematic review.

PubMed

Alsubaie, Modi; Abbott, Rebecca; Dunn, Barnaby; Dickens, Chris; Keil, Tina Frieda; Henley, William; Kuyken, Willem

2017-07-01

Recently, there has been an increased interest in studying the effects of mindfulness-based interventions for people with psychological and physical problems. However, the mechanisms of action in these interventions that lead to beneficial physical and psychological outcomes have yet to be clearly identified. The aim of this paper is to review, systematically, the evidence to date on the mechanisms of action in mindfulness interventions in populations with physical and/or psychological conditions. Searches of seven databases (PsycINFO, Medline (Ovid), Cochrane Central Register of Controlled Trials, EMBASE, CINAHL, AMED, ClinicalTrials.gov) were undertaken in June 2014 and July 2015. We evaluated to what extent the studies we identified met the criteria suggested by Kazdin for establishing mechanisms of action within a psychological treatment (2007, 2009). We identified four trials examining mechanisms of mindfulness interventions in those with comorbid psychological and physical health problems and 14 in those with psychological conditions. These studies examined a diverse range of potential mechanisms, including mindfulness and rumination. Of these candidate mechanisms, the most consistent finding was that greater self-reported change in mindfulness mediated superior clinical outcomes. However, very few studies fully met the Kazdin criteria for examining treatment mechanisms. There was evidence that global changes in mindfulness are linked to better outcomes. This evidence pertained more to interventions targeting psychological rather than physical health conditions. While there is promising evidence that MBCT/MBSR intervention effects are mediated by hypothesised mechanisms, there is a lack of methodological rigour in the field of testing mechanisms of action for both MBCT and MBSR, which precludes definitive conclusions. Copyright © 2017 Elsevier Ltd. All rights reserved.

PelePhysics

DOE Office of Scientific and Technical Information (OSTI.GOV)

2017-05-17

PelePhysics is a suite of physics packages that provides functionality of use to reacting hydrodynamics CFD codes. The initial release includes an interface to reaction rate mechanism evaluation, transport coefficient evaluation, and a generalized equation of state (EOS) facility. Both generic evaluators and interfaces to code from externally available tools (Fuego for chemical rates, EGLib for transport coefficients) are provided.

A Course in Fluid Mechanics of Suspensions.

ERIC Educational Resources Information Center

Davis, Robert H.

1989-01-01

Discusses a course focusing on fluid mechanics and physical chemistry of suspensions. Describes the main themes of the lectures and includes a list of course outlines. Possible textbooks and many journal articles are listed. (YP)

Fool-proofing design and crisis management for customized intelligent physical fitness and healthcare system.

PubMed

Huang, Chung-Chi; Huang, Chung-Lin; Liu, Hsiao-Man

2015-01-01

In recent years, it is quite important to develop a customized system which can enhance physical fitness and health for people. And the system reliability is more important. In the paper, a fool-proofing design and crisis management for customized physical fitness and healthcare system is proposed. It is designed to prevent the failure of the various mechanisms of customized physical fitness and healthcare system, including records, surveillance, assessments, predictions, diagnosis, prescription, and scheduling. It is separated into (1) fool-proofing design module (2) crisis management module. The fool-proofing indexes are set to prevent the failure of the various mechanisms. The states of the various mechanisms are managed by the auto-checked fool-proofing indexes. If mistakes prevention was fail, we have to execute the crisis management for stopping harmful results. The crisis management will find the error level and response the solution by using fuzzy method. By the experiments, we can find the advantages of the fool-proofing design and crisis management for customized physical fitness and healthcare system. And it is effective to prevent the failure of the various mechanisms of intelligent customized physical fitness and healthcare system.

Some Experiments with Biological Applications for the Elementary Laboratory

ERIC Educational Resources Information Center

Kammer, D. W.; Williams, J. A.

1975-01-01

Summarizes physics laboratory experiments with applications in the biological sciences. Includes the following topics: mechanics of the human arm, fluid flow in tubes, physics of learning, the electrocardiograph, nerve impulse conduction, and corrective lenses for eye defects. (Author/MLH)

NASA Tech Briefs, July 1995. Volume 19, No. 7

NASA Technical Reports Server (NTRS)

1995-01-01

Topics include: mechanical components, electronic components and circuits, electronic systems, physical sciences, materials, computer programs, mechanics, machinery, manufacturing/fabrication, mathematics and information sciences, book and reports, and a special section of Federal laboratory computing Tech Briefs.

In vitro physical stimulation of tissue-engineered and native cartilage.

PubMed

Li, Kelvin W; Klein, Travis J; Chawla, Kanika; Nugent, Gayle E; Bae, Won C; Sah, Robert L

2004-01-01

Because of the limited availability of donor cartilage for resurfacing defects in articular surfaces, there is tremendous interest in the in vitro bioengineering of cartilage replacements for clinical applications. However, attaining mechanical properties in engineered cartilaginous constructs that approach those of native cartilage has not been previously achieved when constructs are cultured under free-swelling conditions. One approach toward stimulating the development of constructs that are mechanically more robust is to expose them to physical environments that are similar, in certain ways, to those encountered by native cartilage. This is a strategy motivated by observations in numerous short-term experiments that certain mechanical signals are potent stimulators of cartilage metabolism. On the other hand, excess mechanical loading can have a deleterious effect on cartilage. Culture conditions that include a physical stimulation component are made possible by the use of specialized bioreactors. This chapter addresses some of the issues involved in using bioreactors as integral components of cartilage tissue engineering and in studying the physical regulation of cartilage. We first consider the generation of cartilaginous constructs in vitro. Next we describe the rationale and design of bioreactors that can impart either mechanical deformation or fluid-induced mechanical signals.

Development of Physics and Control of Multiple Forcing Mechanisms for the Alaska Tsunami Forecast Model

NASA Astrophysics Data System (ADS)

Bahng, B.; Whitmore, P.; Macpherson, K. A.; Knight, W. R.

2016-12-01

The Alaska Tsunami Forecast Model (ATFM) is a numerical model used to forecast propagation and inundation of tsunamis generated by earthquakes or other mechanisms in either the Pacific Ocean, Atlantic Ocean or Gulf of Mexico. At the U.S. National Tsunami Warning Center (NTWC), the use of the model has been mainly for tsunami pre-computation due to earthquakes. That is, results for hundreds of hypothetical events are computed before alerts, and are accessed and calibrated with observations during tsunamis to immediately produce forecasts. The model has also been used for tsunami hindcasting due to submarine landslides and due to atmospheric pressure jumps, but in a very case-specific and somewhat limited manner. ATFM uses the non-linear, depth-averaged, shallow-water equations of motion with multiply nested grids in two-way communications between domains of each parent-child pair as waves approach coastal waters. The shallow-water wave physics is readily applicable to all of the above tsunamis as well as to tides. Recently, the model has been expanded to include multiple forcing mechanisms in a systematic fashion, and to enhance the model physics for non-earthquake events.ATFM is now able to handle multiple source mechanisms, either individually or jointly, which include earthquake, submarine landslide, meteo-tsunami and tidal forcing. As for earthquakes, the source can be a single unit source or multiple, interacting source blocks. Horizontal slip contribution can be added to the sea-floor displacement. The model now includes submarine landslide physics, modeling the source either as a rigid slump, or as a viscous fluid. Additional shallow-water physics have been implemented for the viscous submarine landslides. With rigid slumping, any trajectory can be followed. As for meteo-tsunami, the forcing mechanism is capable of following any trajectory shape. Wind stress physics has also been implemented for the meteo-tsunami case, if required. As an example of multiple sources, a near-field model of the tsunami produced by a combination of earthquake and submarine landslide forcing which happened in Papua New Guinea on July 17, 1998 is provided.

The Role of Self-Efficacy and Friend Support on Adolescent Vigorous Physical Activity

ERIC Educational Resources Information Center

Hamilton, Kyra; Warner, Lisa M.; Schwarzer, Ralf

2017-01-01

Objectives: Physical activity, including some form of vigorous activity, is a key component of a healthy lifestyle in young people. Self-efficacy and social support have been identified as key determinants of physical activity; however, the mechanism that reflects the interplay of these two factors is not well understood. The aim of the current…

Student Responses to a Flipped Introductory Physics Class with built-in Post-Video Feedback Quizzes

NASA Astrophysics Data System (ADS)

Ramos, Roberto

We present and analyze student responses to multiple Introductory physics classes in a university setting, taught in a ''flipped'' class format. The classes included algebra- and calculus-based introductory physics. Outside class, students viewed over 100 online video lectures on Classical Mechanics, Electricity and Magnetism, and Modern Physics prepared by this author and in some cases, by a third-party lecture package available over YouTube. Inside the class, students solved and discussed problems and conceptual issues in greater detail. A pre-class online quiz was deployed as an important source of feedback. I will report on the student reactions to the feedback mechanism, student responses using data based on anonymous surveys, as well as on learning gains from pre-/post- physics diagnostic tests. The results indicate a broad mixture of responses to different lecture video packages that depend on learning styles and perceptions. Students preferred the online quizzes as a mechanism to validate their understanding. The learning gains based on FCI and CSEM surveys were significant.

The mechanism of thermal-gradient mass transfer in the sodium hydroxide-nickel system

NASA Technical Reports Server (NTRS)

May, Charles E

1958-01-01

"Thermal-gradient mass transfer" was investigated in the molten sodium hydroxide-nickel system. Possible mechanisms (physical, electrochemical, and chemical) are discussed in terms of experimental and theoretical evidence. Experimental details are included in appendixes.

Mechanics of Ballast Compaction. Volume 5 : Summary Report.

DOT National Transportation Integrated Search

1982-03-01

This report summarizes the results of research on the mechanics of ballast compaction. Details are provided in four preceeding reports. The scope of this summary includes: (1) a description of ballast physical state, (2) methods developed for measuri...

New Physical Mechanism for Lightning

NASA Astrophysics Data System (ADS)

Artekha, Sergey N.; Belyan, Andrey V.

2018-02-01

The article is devoted to electromagnetic phenomena in the atmosphere. The set of experimental data on the thunderstorm activity is analyzed. It helps to identify a possible physical mechanism of lightning flashes. This mechanism can involve the formation of metallic bonds in thunderclouds. The analysis of the problem is performed at a microphysical level within the framework of quantum mechanics. The mechanism of appearance of metallic conductivity includes the resonant tunneling of electrons along resonance-percolation trajectories. Such bonds allow the charges from the vast cloud charged subsystems concentrate quickly in lightning channel. The formation of metal bonds in the thunderstorm cloudiness is described as the second-order phase transition. A successive mechanism for the process of formation and development of the lightning channel is suggested. This mechanism is associated with the change in the orientation of crystals in growing electric field. Possible consequences of the quantum-mechanical mechanism under discussion are compared with the results of observations.

2D Quantum Simulation of MOSFET Using the Non Equilibrium Green's Function Method

NASA Technical Reports Server (NTRS)

Svizhenko, Alexel; Anantram, M. P.; Govindan, T. R.; Yan, Jerry (Technical Monitor)

2000-01-01

The objectives this viewgraph presentation summarizes include: (1) the development of a quantum mechanical simulator for ultra short channel MOSFET simulation, including theory, physical approximations, and computer code; (2) explore physics that is not accessible by semiclassical methods; (3) benchmarking of semiclassical and classical methods; and (4) study other two-dimensional devices and molecular structure, from discretized Hamiltonian to tight-binding Hamiltonian.

Rate Constants and Mechanisms of Protein–Ligand Binding

PubMed Central

Pang, Xiaodong; Zhou, Huan-Xiang

2017-01-01

Whereas protein–ligand binding affinities have long-established prominence, binding rate constants and binding mechanisms have gained increasing attention in recent years. Both new computational methods and new experimental techniques have been developed to characterize the latter properties. It is now realized that binding mechanisms, like binding rate constants, can and should be quantitatively determined. In this review, we summarize studies and synthesize ideas on several topics in the hope of providing a coherent picture of and physical insight into binding kinetics. The topics include microscopic formulation of the kinetic problem and its reduction to simple rate equations; computation of binding rate constants; quantitative determination of binding mechanisms; and elucidation of physical factors that control binding rate constants and mechanisms. PMID:28375732

Theoretical Fluid Mechanics

NASA Astrophysics Data System (ADS)

Fitzpatrick, Richard

2017-12-01

'Theoretical Fluid Mechanics' has been written to aid physics students who wish to pursue a course of self-study in fluid mechanics. It is a comprehensive, completely self-contained text with equations of fluid mechanics derived from first principles, and any required advanced mathematics is either fully explained in the text, or in an appendix. It is accompanied by about 180 exercises with completely worked out solutions. It also includes extensive sections on the application of fluid mechanics to topics of importance in astrophysics and geophysics. These topics include the equilibrium of rotating, self-gravitating, fluid masses; tidal bores; terrestrial ocean tides; and the Eddington solar model.

DNA-PK Promotes the Mitochondrial, Metabolic, and Physical Decline that Occurs During Aging.

PubMed

Park, Sung-Jun; Gavrilova, Oksana; Brown, Alexandra L; Soto, Jamie E; Bremner, Shannon; Kim, Jeonghan; Xu, Xihui; Yang, Shutong; Um, Jee-Hyun; Koch, Lauren G; Britton, Steven L; Lieber, Richard L; Philp, Andrew; Baar, Keith; Kohama, Steven G; Abel, E Dale; Kim, Myung K; Chung, Jay H

2017-05-02

Hallmarks of aging that negatively impact health include weight gain and reduced physical fitness, which can increase insulin resistance and risk for many diseases, including type 2 diabetes. The underlying mechanism(s) for these phenomena is poorly understood. Here we report that aging increases DNA breaks and activates DNA-dependent protein kinase (DNA-PK) in skeletal muscle, which suppresses mitochondrial function, energy metabolism, and physical fitness. DNA-PK phosphorylates threonines 5 and 7 of HSP90α, decreasing its chaperone function for clients such as AMP-activated protein kinase (AMPK), which is critical for mitochondrial biogenesis and energy metabolism. Decreasing DNA-PK activity increases AMPK activity and prevents weight gain, decline of mitochondrial function, and decline of physical fitness in middle-aged mice and protects against type 2 diabetes. In conclusion, DNA-PK is one of the drivers of the metabolic and fitness decline during aging, and therefore DNA-PK inhibitors may have therapeutic potential in obesity and low exercise capacity. Published by Elsevier Inc.

Popular and Nonpopular Subtypes of Physically Aggressive Preadolescents: Continuity of Aggression and Peer Mechanisms during the Transition to Middle School

ERIC Educational Resources Information Center

Shi, Bing; Xie, Hongling

2012-01-01

Using peer nominations of physical aggression and perceived popularity in the spring semester of fifth grade, we identified 54 popular aggressive and 42 nonpopular aggressive preadolescents in a diverse sample of 318 participants recruited from an urban school district. Physical aggression in the spring semester of sixth grade was included to…

Resource Letter MPF-1: Mechanical Properties of Fluids

ERIC Educational Resources Information Center

Stanley, R. C.

1974-01-01

Presents an annotated bibliography concerning the mechanical properties of fluids, including topics for use at elementary, secondary, undergraduate, and graduate levels. Indicates that the material can particularly help college physicists in improving course contents in specified fields of physics. (CC)

Analyzing Virtual Physics Simulations with Tracker

NASA Astrophysics Data System (ADS)

Claessens, Tom

2017-12-01

In the physics teaching community, Tracker is well known as a user-friendly open source video analysis software, authored by Douglas Brown. With this tool, the user can trace markers indicated on a video or on stroboscopic photos and perform kinematic analyses. Tracker also includes a data modeling tool that allows one to fit some theoretical equations of motion onto experimentally obtained data. In the field of particle mechanics, Tracker has been effectively used for learning and teaching about projectile motion, "toss up" and free-fall vertical motion, and to explain the principle of mechanical energy conservation. Also, Tracker has been successfully used in rigid body mechanics to interpret the results of experiments with rolling/slipping cylinders and moving rods. In this work, I propose an original method in which Tracker is used to analyze virtual computer simulations created with a physics-based motion solver, instead of analyzing video recording or stroboscopic photos. This could be an interesting approach to study kinematics and dynamics problems in physics education, in particular when there is no or limited access to physical labs. I demonstrate the working method with a typical (but quite challenging) problem in classical mechanics: a slipping/rolling cylinder on a rough surface.

PREFACE Physical Aspects of Developmental Biology: 21st Century Perspectives 'On Growth and Form' Physical Aspects of Developmental Biology: 21st Century Perspectives 'On Growth and Form'

NASA Astrophysics Data System (ADS)

Hutson, M. Shane

2008-04-01

There is a long and circuitous route from an organism_s genome to its steady-state adult form—all of which falls under the wide umbrella of developmental biology. Given this breadth, how does one answer the question: what is the mechanism by which developmental event X takes place? The answer depends strongly on what one considers an acceptable explanation. In some scientific circles, the answer would focus on the regulatory genes involved. In others, the focus would be on the signaling pathways activated, or on the associated cellular movements, or maybe even on the intra- and intercellular forces. In the long term, the goal must be to provide an explanation that connects all of these perspectives. During the last several decades, molecular biology has made enormous progress towards understanding development from the genome-side. Unfortunately, progress has been much slower on the relevant physical biology—which had a huge head start in the late 19th century age of developmental mechanics. It is just a slight exaggeration to claim that we_ve made little progress on the physical side since D_Arcy Thompson_s On Growth and Form in 1917. Hopefully, such statements will be recognized as large exaggerations in years to come as developmental mechanics is now in resurgence. This special issue of Physical Biology brings together current work in developmental mechanics from an international cadre of scientists—including physicists, biologists and engineers. The works include both models and experiments. They span scales from subcellular microrheology to finite element models of entire embryos. I hope that students looking for one of these articles will dive into the rest. The field of developmental mechanics is in the process of training a new generation of students who are comfortable with both the necessary biology and physics. Enormous opportunities are available for those who can work across those traditional disciplinary boundaries.

Reduction of Helicopter Blade-Vortex Interaction Noise by Active Rotor Control Technology

NASA Technical Reports Server (NTRS)

Yu, Yung H.; Gmelin, Bernd; Splettstoesser, Wolf; Brooks, Thomas F.; Philippe, Jean J.; Prieur, Jean

1997-01-01

Helicopter blade-vortex interaction noise is one of the most severe noise sources and is very important both in community annoyance and military detection. Research over the decades has substantially improved basic physical understanding of the mechanisms generating rotor blade-vortex interaction noise and also of controlling techniques, particularly using active rotor control technology. This paper reviews active rotor control techniques currently available for rotor blade vortex interaction noise reduction, including higher harmonic pitch control, individual blade control, and on-blade control technologies. Basic physical mechanisms of each active control technique are reviewed in terms of noise reduction mechanism and controlling aerodynamic or structural parameters of a blade. Active rotor control techniques using smart structures/materials are discussed, including distributed smart actuators to induce local torsional or flapping deformations, Published by Elsevier Science Ltd.

QuVis interactive simulations: tools to support quantum mechanics instruction

NASA Astrophysics Data System (ADS)

Kohnle, Antje

2015-04-01

Quantum mechanics holds a fascination for many students, but its mathematical complexity and counterintuitive results can present major barriers. The QuVis Quantum Mechanics Visualization Project (www.st-andrews.ac.uk/physics/quvis) aims to overcome these issues through the development and evaluation of interactive simulations with accompanying activities for the learning and teaching of quantum mechanics. Over 90 simulations are now available on the QuVis website. One collection of simulations is embedded in the Institute of Physics Quantum Physics website (quantumphysics.iop.org), which consists of freely available resources for an introductory course in quantum mechanics starting from two-level systems. Simulations support model-building by reducing complexity, focusing on fundamental ideas and making the invisible visible. They promote engaged exploration, sense-making and linking of multiple representations, and include high levels of interactivity and direct feedback. Simulations are research-based and evaluation with students informs all stages of the development process. Simulations are iteratively refined using student feedback in individual observation sessions and in-class trials. Evaluation has shown that the simulations can help students learn quantum mechanics concepts at both the introductory and advanced undergraduate level and that students perceive simulations to be beneficial to their learning. Recent activity includes the launch of a new collection of HTML5 simulations that run on both desktop and tablet-based devices and the introduction of a goal and reward structure in simulations through the inclusion of challenges. This presentation will give an overview of the QuVis resources, highlight recent work and outline future plans. QuVis is supported by the UK Institute of Physics, the UK Higher Education Academy and the University of St Andrews.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Libby, S B; Weiss, M S

Edward Teller was one of the great physicists of the twentieth century. His career began just after the key ideas of the quantum revolution of the 1920's were completed, opening vast areas of physics and chemistry to detailed understanding. Thus, his early work in theoretical physics focused on applying the new quantum theory to the understanding of diverse phenomena. These topics included chemical physics, diamagnetism, and nuclear physics. Later, he made key contributions to statistical mechanics, surface physics, solid state, and plasma physics. In many cases, the ideas in these papers are still rich with important ramifications.

Upper-Division Student Difficulties with Separation of Variables

ERIC Educational Resources Information Center

Wilcox, Bethany R.; Pollock, Steven J.

2015-01-01

Separation of variables can be a powerful technique for solving many of the partial differential equations that arise in physics contexts. Upper-division physics students encounter this technique in multiple topical areas including electrostatics and quantum mechanics. To better understand the difficulties students encounter when utilizing the…

The Symmetry of Natural Laws.

ERIC Educational Resources Information Center

Brown, Laurie M.

This document is a monograph intended for advanced undergraduate students, or beginning graduate students, who have some knowledge of modern physics as well as classical physics, including the elementary quantum mechanical treatment of the hydrogen atom and angular momentum. The first chapter introduces symmetry and relates it to the mathematical…

Factors Influencing Learning of Classical Mechanics.

ERIC Educational Resources Information Center

Champagne, Audrey B.; And Others

Beginning college physics students' misconceptions about moving objects, their mathematics skills, and formal reasoning ability, are all believed to be related to their achievement in physics. It is hypothesized that students whose knowledge structures include misconceptions that are in conflict with concepts in the lectures and text will have…

Report on the solar physics-plasma physics workshop

NASA Technical Reports Server (NTRS)

Sturrock, P. A.; Baum, P. J.; Beckers, J. M.; Newman, C. E.; Priest, E. R.; Rosenberg, H.; Smith, D. F.; Wentzel, D. G.

1976-01-01

The paper summarizes discussions held between solar physicists and plasma physicists on the interface between solar and plasma physics, with emphasis placed on the question of what laboratory experiments, or computer experiments, could be pursued to test proposed mechanisms involved in solar phenomena. Major areas discussed include nonthermal plasma on the sun, spectroscopic data needed in solar plasma diagnostics, types of magnetic field structures in the sun's atmosphere, the possibility of MHD phenomena involved in solar eruptive phenomena, the role of non-MHD instabilities in energy release in solar flares, particle acceleration in solar flares, shock waves in the sun's atmosphere, and mechanisms of radio emission from the sun.

Biophysics of the Senses

NASA Astrophysics Data System (ADS)

Presley, Tennille D.

2016-12-01

Biophysics of the Senses connects fundamental properties of physics to biological systems, relating them directly to the human body. It includes discussions of the role of charges and free radicals in disease and homeostasis, how aspects of mechanics impact normal body functions, human bioelectricity and circuitry, forces within the body, and biophysical sensory mechanisms. This is an exciting view of how sensory aspects of biophysics are utilized in everyday life for students who are curious but struggle with the connection between biology and physics.

GaAs-based micro/nanomechanical resonators

NASA Astrophysics Data System (ADS)

Yamaguchi, Hiroshi

2017-10-01

Micro/nanomechanical resonators have been extensively studied both for device applications, such as high-performance sensors and high-frequency devices, and for fundamental science, such as quantum physics in macroscopic objects. The advantages of GaAs-based semiconductor heterostructures include improved mechanical properties through strain engineering, highly controllable piezoelectric transduction, carrier-mediated optomechanical coupling, and hybridization with quantum low-dimensional structures. This article reviews our recent activities, as well as those of other groups, on the physics and applications of mechanical resonators fabricated using GaAs-based heterostructures.

Physical Exercise for the Treatment of Neuropsychiatric Disturbances in Alzheimer's Dementia: Possible Mechanisms, Current Evidence and Future Directions.

PubMed

Matura, Silke; Carvalho, André F; Alves, Gilberto S; Pantel, Johannes

2016-01-01

Behavioral and psychological symptoms of dementia (BPSD), also known as neuropsychiatric or non-cognitive symptoms are common and often distressing features of Alzheimer's Dementia. BPSD significantly increase patient suffering, early institutionalization and caregiver's burden. The clinical management of BPSD is dominated by a pharmacological approach, although these medications often come with serious adverse side-effects. There are only few nonpharmacological treatment strategies for BPSD. A substantial amount of intervention studies that have investigated non-pharmacological treatment options for BPSD have focused on physical exercise. Although these studies are very heterogeneous in terms of type and severity of dementia, as well as type and duration of the exercise intervention, the overall picture shows a positive effect of physical exercise in alleviating BPSD. There is evidence that numerous mechanisms contribute to the positive effect of physical exercise on BPSD. No attempt has been undertaken so far to give an overview of the existing knowledge regarding these mechanisms. Therefore, the current review aims to integrate the existing evidence on psychological and neurobiological mechanisms that contribute to the beneficial effects of physical exercise in ameliorating BPSD in Alzheimer's dementia. A discussion of psychological mechanisms such as improved sleep and stress reduction will be followed by a discussion of neurobiological mechanisms including the exercise induced change in neurotransmitter concentrations, increased synthesis of neurotrophins and immune activation. The review closes with recommendations for future research to overcome the shortcomings of existing studies and broaden the current knowledge on the positive effects of physical exercise on BPSD.

Quantum Mechanics for Everyone: Can it be done with Technology?

NASA Astrophysics Data System (ADS)

Zollman, Dean

2004-10-01

The Visual Quantum Mechanics project has created a series of teaching/learning units to introduce quantum physics to a variety of audiences ranging from high school students who normally would not study these topics to undergraduate physics majors. Most recently we have been developing materials relating modern medical procedures and contemporary physics. In all of these materials interactive computer visualizations are coupled with hands-on experiences to create a series of activities which help students learn about some aspects of quantum mechanics. Our goal is to enable students to obtain a qualitative and, where appropriate, a quantitative understanding of contemporary ideas in physics. Included in the instructional materials are student-centered activities that address a variety of concepts in quantum physics and applications to devices such as the light emitting diode, the electron microscope, an inexpensive infrared detection card, and the Star Trek Transporter. Whenever possible the students begin the study of a new concept with an experiment using inexpensive equipment. They, then, build models of the physical phenomenon using interactive computer visualization and conclude by applying those models to new situations. For physics students these visualizations are usually followed by a mathematical approach. For others the visualizations provide a framework for understanding the concepts. Thus, Visual Quantum Mechanics allows a wide range of students to begin to understand the basic concepts, implications and interpretations of quantum physics. At present we are building on this foundation to create materials which show the connection between contemporary physics and modern medical diagnosis. Additional information is available at http://web.phys.ksu.edu/.

Project Physics Teacher Guide 3, The Triumph of Mechanics.

ERIC Educational Resources Information Center

Harvard Univ., Cambridge, MA. Harvard Project Physics.

Teaching procedures of Project Physics Unit 3 are presented to help teachers make effective use of learning materials. Unit contents are discussed in connection with teaching aid perspective, multi-media schedules, schedule blocks, and resource charts. Brief analyses are made for transparencies, 16mm films, and reader articles. Included is…

[Physical therapy for scars].

PubMed

Masanovic, Marguerite Guillot

2013-01-01

Physical therapy consists notably of hand or mechanical massages, pressure therapy using various fabrics or splints, cryotherapy, laser therapy, etc. It forms part of the range of therapies used to treat pathological scars, including medical and surgical treatment. While the results are often satisfactory for hypertrophic scars, they remain uncertain for major keloids.

Physical activity parenting: A systematic review of questionnaires and their associations with child activity levels

USDA-ARS?s Scientific Manuscript database

Insufficient physical activity (PA) is considered a critical contributor to childhood overweight. Parents are a key in influencing their child's PA through various mechanisms of PA parenting, including support, restriction of PA, and facilitation of enrollment in PA classes or activities. However, s...

PHYSICS FOR IOWA SCHOOLS.

ERIC Educational Resources Information Center

TWEETEN, PAUL W.

THIS GUIDE FOR TEACHING HIGH SCHOOL PHYSICS INCLUDES--(1) CONCEPTS, (2) UNDERSTANDINGS, (3) ACTIVITIES, (4) REFERENCES, (5) AUDIOVISUAL AIDS, (6) EQUIPMENT, AND (7) REQUIRED SUPPLIES. THE COURSE CONTENT IS DIVIDED INTO EIGHT MAJOR TOPICS--(1) FUNDAMENTALS, (2) MECHANICS, (3) HEAT, (4) SOUND, (5) LIGHT, (6) ELECTRICITY, (7) SPACE, TIME, AND MOTION,…

Mechanical design of translocating motor proteins.

PubMed

Hwang, Wonmuk; Lang, Matthew J

2009-01-01

Translocating motors generate force and move along a biofilament track to achieve diverse functions including gene transcription, translation, intracellular cargo transport, protein degradation, and muscle contraction. Advances in single molecule manipulation experiments, structural biology, and computational analysis are making it possible to consider common mechanical design principles of these diverse families of motors. Here, we propose a mechanical parts list that include track, energy conversion machinery, and moving parts. Energy is supplied not just by burning of a fuel molecule, but there are other sources or sinks of free energy, by binding and release of a fuel or products, or similarly between the motor and the track. Dynamic conformational changes of the motor domain can be regarded as controlling the flow of free energy to and from the surrounding heat reservoir. Multiple motor domains are organized in distinct ways to achieve motility under imposed physical constraints. Transcending amino acid sequence and structure, physically and functionally similar mechanical parts may have evolved as nature's design strategy for these molecular engines.

Mechanical Design of Translocating Motor Proteins

PubMed Central

Lang, Matthew J.

2013-01-01

Translocating motors generate force and move along a biofilament track to achieve diverse functions including gene transcription, translation, intracellular cargo transport, protein degradation, and muscle contraction. Advances in single molecule manipulation experiments, structural biology, and computational analysis are making it possible to consider common mechanical design principles of these diverse families of motors. Here, we propose a mechanical parts list that include track, energy conversion machinery, and moving parts. Energy is supplied not just by burning of a fuel molecule, but there are other sources or sinks of free energy, by binding and release of a fuel or products, or similarly between the motor and the track. Dynamic conformational changes of the motor domain can be regarded as controlling the flow of free energy to and from the surrounding heat reservoir. Multiple motor domains are organized in distinct ways to achieve motility under imposed physical constraints. Transcending amino acid sequence and structure, physically and functionally similar mechanical parts may have evolved as nature’s design strategy for these molecular engines. PMID:19452133

Evaluation of coupling approaches for thermomechanical simulations

DOE PAGES

Novascone, S. R.; Spencer, B. W.; Hales, J. D.; ...

2015-08-10

Many problems of interest, particularly in the nuclear engineering field, involve coupling between the thermal and mechanical response of an engineered system. The strength of the two-way feedback between the thermal and mechanical solution fields can vary significantly depending on the problem. Contact problems exhibit a particularly high degree of two-way feedback between those fields. This paper describes and demonstrates the application of a flexible simulation environment that permits the solution of coupled physics problems using either a tightly coupled approach or a loosely coupled approach. In the tight coupling approach, Newton iterations include the coupling effects between all physics,more » while in the loosely coupled approach, the individual physics models are solved independently, and fixed-point iterations are performed until the coupled system is converged. These approaches are applied to simple demonstration problems and to realistic nuclear engineering applications. The demonstration problems consist of single and multi-domain thermomechanics with and without thermal and mechanical contact. Simulations of a reactor pressure vessel under pressurized thermal shock conditions and a simulation of light water reactor fuel are also presented. Here, problems that include thermal and mechanical contact, such as the contact between the fuel and cladding in the fuel simulation, exhibit much stronger two-way feedback between the thermal and mechanical solutions, and as a result, are better solved using a tight coupling strategy.« less

Separability and Non-Individuality: Is It Possible to Conciliate (At Least A Form Of) Einstein's Realism with Quantum Mechanics?

NASA Astrophysics Data System (ADS)

Krause, Décio; Arenhart, Jonas R. B.

2014-12-01

In this paper we argue that physical theories, including quantum mechanics, refer to some kind of `objects', even if only implicitly. We raise questions about the logico-mathematical apparatuses commonly employed in such theories, bringing to light some metaphysical presuppositions underlying such apparatuses. We point out to some incongruities in the discourse holding that quantum objects would be entities of some `new kind' while still adhering to the logico-mathematical framework we use to deal with classical objects. The use of such apparatus would hinder us from being in complete agreement with the ontological novelties the theories of quanta seem to advance. Thus, we join those who try to investigate a `logic of quantum mechanics', but from a different point of view: looking for a formal foundation for a supposed new ontology. As a consequence of this move, we can revisit Einstein's ideas on physical reality and propose that, by considering a new kind of object traditionally termed `non-individuals', it is possible to sustain that they still obey some of Einstein's conditions for `physical realities', so that it will be possible to talk of a `principle of separability' in a sense which is not in complete disagreement with quantum mechanics. So, Einstein's departure from quantum mechanics might be softened at least concerning a form of his realism, which sees separated physical objects as distinct `physical realities'.

Physical Activity for Cognitive and Mental Health in Youth: A Systematic Review of Mechanisms.

PubMed

Lubans, David; Richards, Justin; Hillman, Charles; Faulkner, Guy; Beauchamp, Mark; Nilsson, Michael; Kelly, Paul; Smith, Jordan; Raine, Lauren; Biddle, Stuart

2016-09-01

Physical activity can improve cognitive and mental health, but the underlying mechanisms have not been established. To present a conceptual model explaining the mechanisms for the effect of physical activity on cognitive and mental health in young people and to conduct a systematic review of the evidence. Six electronic databases (PubMed, PsycINFO, SCOPUS, Ovid Medline, SportDiscus, and Embase) were used. School-, home-, or community-based physical activity intervention or laboratory-based exercise interventions were assessed. Studies were eligible if they reported statistical analyses of changes in the following: (1) cognition or mental health; and (2) neurobiological, psychosocial, and behavioral mechanisms. Data relating to methods, assessment period, participant characteristics, intervention type, setting, and facilitator/delivery were extracted. Twenty-five articles reporting results from 22 studies were included. Mechanisms studied were neurobiological (6 studies), psychosocial (18 studies), and behavioral (2 studies). Significant changes in at least 1 potential neurobiological mechanism were reported in 5 studies, and significant effects for at least 1 cognitive outcome were also found in 5 studies. One of 2 studies reported a significant effect for self-regulation, but neither study reported a significant impact on mental health. Small number of studies and high levels of study heterogeneity. The strongest evidence was found for improvements in physical self-perceptions, which accompanied enhanced self-esteem in the majority of studies measuring these outcomes. Few studies examined neurobiological and behavioral mechanisms, and we were unable to draw conclusions regarding their role in enhancing cognitive and mental health. Copyright © 2016 by the American Academy of Pediatrics.

NASA Tech Briefs, December 1991. Volume 15, No. 12

NASA Technical Reports Server (NTRS)

1991-01-01

Topics include: Electronic Components and Circuits. Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Fabrication Technology, Mathematics and Information Sciences,

NASA Tech Briefs, December 2002

NASA Technical Reports Server (NTRS)

2002-01-01

Topics covered include: Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; and Life Sciences.

Probe Beam Deflection Optical Imaging of Thermal and mechanical Phenomena Resulting from Nanosecond Electric Pulse (nsEP) Exposure In-Vitro

DTIC Science & Technology

of plasma membranes of eukaryotic cells in vitro and in vivo. The physical to biological driving mechanisms behind nanoporation still remain unclear...but could be a result of a multitude of stimuli, including mechanical (shockwaves, electrode formation), thermal, and electrical (ion transport...channel gating). Experimentally quantifying and characterizing mechanical fields with piezoelectric transducers proves difficult due to electromagnetic

Modified Continuum Mechanics Modeling on Size-Dependent Properties of Piezoelectric Nanomaterials: A Review

PubMed Central

Yan, Zhi; Jiang, Liying

2017-01-01

Piezoelectric nanomaterials (PNs) are attractive for applications including sensing, actuating, energy harvesting, among others in nano-electro-mechanical-systems (NEMS) because of their excellent electromechanical coupling, mechanical and physical properties. However, the properties of PNs do not coincide with their bulk counterparts and depend on the particular size. A large amount of efforts have been devoted to studying the size-dependent properties of PNs by using experimental characterization, atomistic simulation and continuum mechanics modeling with the consideration of the scale features of the nanomaterials. This paper reviews the recent progresses and achievements in the research on the continuum mechanics modeling of the size-dependent mechanical and physical properties of PNs. We start from the fundamentals of the modified continuum mechanics models for PNs, including the theories of surface piezoelectricity, flexoelectricity and non-local piezoelectricity, with the introduction of the modified piezoelectric beam and plate models particularly for nanostructured piezoelectric materials with certain configurations. Then, we give a review on the investigation of the size-dependent properties of PNs by using the modified continuum mechanics models, such as the electromechanical coupling, bending, vibration, buckling, wave propagation and dynamic characteristics. Finally, analytical modeling and analysis of nanoscale actuators and energy harvesters based on piezoelectric nanostructures are presented. PMID:28336861

Modified Continuum Mechanics Modeling on Size-Dependent Properties of Piezoelectric Nanomaterials: A Review.

PubMed

Yan, Zhi; Jiang, Liying

2017-01-26

Piezoelectric nanomaterials (PNs) are attractive for applications including sensing, actuating, energy harvesting, among others in nano-electro-mechanical-systems (NEMS) because of their excellent electromechanical coupling, mechanical and physical properties. However, the properties of PNs do not coincide with their bulk counterparts and depend on the particular size. A large amount of efforts have been devoted to studying the size-dependent properties of PNs by using experimental characterization, atomistic simulation and continuum mechanics modeling with the consideration of the scale features of the nanomaterials. This paper reviews the recent progresses and achievements in the research on the continuum mechanics modeling of the size-dependent mechanical and physical properties of PNs. We start from the fundamentals of the modified continuum mechanics models for PNs, including the theories of surface piezoelectricity, flexoelectricity and non-local piezoelectricity, with the introduction of the modified piezoelectric beam and plate models particularly for nanostructured piezoelectric materials with certain configurations. Then, we give a review on the investigation of the size-dependent properties of PNs by using the modified continuum mechanics models, such as the electromechanical coupling, bending, vibration, buckling, wave propagation and dynamic characteristics. Finally, analytical modeling and analysis of nanoscale actuators and energy harvesters based on piezoelectric nanostructures are presented.

Method and apparatus for separating material

DOEpatents

Oder, Robin R.; Jamison, Russell E.

2006-10-24

An apparatus for sorting particles composed of a mixture of particles with differing physical and chemical characteristics. The apparatus includes a comminutor, a mechanism for removing particles from the inside of the comminutor which are intermediate in size between the feed to the comminutor and the product of comminution, a mechanism for either discharging particles taken from the comminutor to a reject stream or providing them to a size classification apparatus such as screening, a mechanism for returning the oversize particles to the comminutor or for discharging them to the reject stream, an electric mechanism for separating particles with an electrical force disposed adjacent to a magnet mechanism, a mechanism for providing the particles to the magnet mechanism and the electric mechanism and for providing triboelectric and capacitive charges to the particles, and a mechanism for returning one of the products of electric and magnetic separation to the comminutor while discharging the other to the reject stream. A method for sorting particles composed of a mixture of particles with differing physical and chemical characteristics.

Theory of time-dependent rupture in the Earth

NASA Technical Reports Server (NTRS)

Das, S.; Scholz, C. H.

1980-01-01

Fracture mechanics is used to develop a theory of earthquake mechanism which includes the phenomenon of subcritical crack growth. The following phenomena are predicted: slow earthquakes, multiple events, delayed multiple events (doublets), postseismic rupture growth and afterslip, foreshocks, and aftershocks. The theory predicts a nucleation stage prior to an earthquake, and suggests a physical mechanism by which one earthquake may 'trigger' another.

NASA Tech Briefs, November 1991. Volume 15, No. 11

NASA Technical Reports Server (NTRS)

1991-01-01

Topics include: Electronic Components & and Circuits. Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Fabrication Technology, and Mathematics and Information Sciences,

Texas Science Teacher Characteristics and Conceptual Understanding of Newton's Laws of Motion

NASA Astrophysics Data System (ADS)

Busby, Karin Burk

Misconceptions of Newtonian mechanics and other physical science concepts are well documented in primary and pre-service teacher populations (Burgoon, Heddle, & Duran, 2009; Allen & Coole, 2012; Kruger, Summers, & Palacio, 1990; Ginns & Watters, 1995; Trumper, 1999; Asikainen & Hirovonen, 2014). These misconceptions match the misconceptions held by students, leaving teachers ill-equipped to rectify these concepts in the classroom (Kind, 2014; Kruger et al., 1990; Cochran & Jones, 1998). Little research has been devoted to misconceptions held by in-service secondary teachers, the population responsible for teaching Newtonian mechanics. This study focuses on Texas in-service science teachers in middle school and high school science, specifically sixth grade science, seventh grade science, eighth grade science, integrated physics and chemistry, and physics teachers. This study utilizes two instruments to gauge conceptual understanding of Newton's laws of motion: the Force Concept Inventory [FCI] (Hestenes, Wells, & Swackhamer, 1992) and a custom instrument developed for the Texas Regional Collaboratives for Excellence in Science and Mathematics Teaching (Urquhart, M., e-mail, April 4, 2017). Use of each instrument had its strengths and limitations. In the initial work of this study, the FCI was given to middle and high school teacher volunteers in two urban school districts in the Dallas- Fort Worth area to assess current conceptual understanding of Newtonian mechanics. Along with the FCI, each participant was asked to complete a demographic survey. Demographic data collected included participant's sex, years of service in teaching position, current teaching position, degrees, certification type, and current certifications for science education. Correlations between variables and overall average on the FCI were determined by t-tests and ANOVA tests with a post-hoc Holm-Bonferroni correction test. Test questions pertaining to each of Newton's three laws of motion were extrapolated to determine any correlations. The sample size for this study was small (n=24), requiring a second study investigate potential correlations to teacher characteristics. The second study was conducted using the 2013-2014 school year participants in the Texas Regional Collaboratives for Excellence in Science and Mathematics Teaching [TRC] (Texas Regional Collaborative for Excellence in Science and Mathematics Teaching, 2013), a statewide program led by The University of Texas at Austin Center for STEM Education (Texas Regional Collaborative for Excellence in Science and Mathematics Teaching, 2013). Participants completed a demographic survey and took the TRC Physics Assessment instrument developed for the TRC to determine current conceptual understanding of Newtonian mechanics as defined by the Texas Essential Knowledge and Skills. The TRC also collected demographic data including Texas Educational Agency region, participant's sex, years of service in teaching, current teaching position, level of highest degree earned, whether or not the participant had a STEM degree, and certification type. Correlations were determined between overall average and conceptual force questions only. The sample size was substantial (n=368) but due to time constraints in its development, the TRC Physics Assessment was unable to undergo reliability or validity testing before implementation. Test question pertaining to each of Newton's three laws of motion were extrapolated to determine any correlations. A significance value of p= 0.05 was used for all tests. Both content assessments indicated that, on average, teacher-participants had a considerable misunderstanding of Newtonian mechanics with Newton's third law questions especially difficult for the populations. Teachers' current teaching assignment was statistically significant for most tests, suggesting that high school physics teachers have more conceptual understanding of Newtonian mechanics than middle school teachers but have not necessarily mastered Newtonian mechanics. STEM majors and participant's sex were significant only for the TRC Physics Assessment. One outcome of this study is a recommendation that the Texas teacher certification process for middle school science change to include a general science test that includes physical science. Also, in-service science teachers responsible for teaching Newton's laws of motion should participate in specific professional development from a physics content educational expert to address misconceptions. Additional recommendations include that physics teachers take a mentoring role to help other teachers in physical science concepts and that middle school curriculum provide assistance to teachers for addressing misconceptions of Newton's third law.

Project Physics Reader 3, The Triumph of Mechanics.

ERIC Educational Resources Information Center

Harvard Univ., Cambridge, MA. Harvard Project Physics.

As a supplement to Project Physics Unit 3, a collection of articles is presented in this reader for student browsing. Four excerpts are given under the following headings: On the kinetic theory of gases, Maxwell's Demon, Introduction to Waves, and Scientific Cranks. Five articles are included in terms of energy, barometers, randomness, fiddle…

Environmental quality modifies the relationship between county-level leisure-time physical inactivity and obesity in the U.S.

EPA Science Inventory

Background/Aim More than one-third of U.S. adults are obese, making them vulnerable to multiple poor outcomes including diabetes, heart disease, cancer, and death. Physical inactivity is a well-established mechanism contributing to obesity that can be promoted or hindered by nume...

Proceedings of the Geodesy/Solid Earth and Ocean Physics (GEOP) Research Conferences

NASA Technical Reports Server (NTRS)

Mueller, I. I. (Editor)

1975-01-01

Papers are presented dealing with interdisciplinary research in the fields of geodesy, solid earth and ocean physics. Topics discussed include: solid earth and ocean tides; the rotation of the earth and polar motion; vertical crustal motions; the geoid and ocean surface; earthquake mechanism; sea level changes; and lunar dynamics.

Physical Therapy in the Treatment of Central Pain Mechanisms for Female Sexual Pain.

PubMed

Vandyken, Carolyn; Hilton, Sandra

2017-01-01

The complexity of female sexual pain requires an interdisciplinary approach. Physical therapists trained in pelvic health conditions are well positioned to be active members of an interdisciplinary team addressing the assessment and treatment of female sexual pain. Changes within physical therapy practice in the last ten years have resulted in significant utilization of pelvic floor muscle relaxation and manual therapy techniques to address a variety of pelvic pain conditions, including female sexual pain. However, sexual pain is a complex issue giving credence to the necessity of addressing all of the drivers of the pain experience- biological, psychological and social. This review aims to reconcile current pain science with a plan for integrating a biopsychosocial approach into the evaluation and subsequent treatment for female sexual pain for physical therapists. A literature review of the important components of skilled physical therapy interventions is presented including the physical examination, pain biology education, cognitive behavioral influences in treatment design, motivational interviewing as an adjunct to empathetic practice, and the integration of non-threatening movement and mindfulness into treatment. A single case study is used to demonstrate the biopsychosocial framework utilized in this approach. Appropriate measures for assessing psychosocial factors are readily available and inform a reasoned approach for physical therapy design that addresses both peripheral and central pain mechanisms. Decades of research support the integration of a biopsychosocial approach in the treatment of complex pain, including female sexual pain. It is reasonable for physical therapists to utilize evidence based strategies such as CBT, pain biology education, Mindfulness Based Stress Reduction (MBSR), yoga and imagery based exercises to address the biopsychosocial components of female sexual pain. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

Mechanical stress regulates insulin sensitivity through integrin-dependent control of insulin receptor localization.

PubMed

Kim, Jung; Bilder, David; Neufeld, Thomas P

2018-01-15

Insulin resistance, the failure to activate insulin signaling in the presence of ligand, leads to metabolic diseases, including type 2 diabetes. Physical activity and mechanical stress have been shown to protect against insulin resistance, but the molecular mechanisms remain unclear. Here, we address this relationship in the Drosophila larval fat body, an insulin-sensitive organ analogous to vertebrate adipose tissue and livers. We found that insulin signaling in Drosophila fat body cells is abolished in the absence of physical activity and mechanical stress even when excess insulin is present. Physical movement is required for insulin sensitivity in both intact larvae and fat bodies cultured ex vivo. Interestingly, the insulin receptor and other downstream components are recruited to the plasma membrane in response to mechanical stress, and this membrane localization is rapidly lost upon disruption of larval or tissue movement. Sensing of mechanical stimuli is mediated in part by integrins, whose activation is necessary and sufficient for mechanical stress-dependent insulin signaling. Insulin resistance develops naturally during the transition from the active larval stage to the immotile pupal stage, suggesting that regulation of insulin sensitivity by mechanical stress may help coordinate developmental programming with metabolism. © 2018 Kim et al.; Published by Cold Spring Harbor Laboratory Press.

Modeling the Coupled Chemo-Thermo-Mechanical Behavior of Amorphous Polymer Networks.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zimmerman, Jonathan A.; Nguyen, Thao D.; Xiao, Rui

2015-02-01

Amorphous polymers exhibit a rich landscape of time-dependent behavior including viscoelasticity, structural relaxation, and viscoplasticity. These time-dependent mechanisms can be exploited to achieve shape-memory behavior, which allows the material to store a programmed deformed shape indefinitely and to recover entirely the undeformed shape in response to specific environmental stimulus. The shape-memory performance of amorphous polymers depends on the coordination of multiple physical mechanisms, and considerable opportunities exist to tailor the polymer structure and shape-memory programming procedure to achieve the desired performance. The goal of this project was to use a combination of theoretical, numerical and experimental methods to investigate themore » effect of shape memory programming, thermo-mechanical properties, and physical and environmental aging on the shape memory performance. Physical and environmental aging occurs during storage and through exposure to solvents, such as water, and can significantly alter the viscoelastic behavior and shape memory behavior of amorphous polymers. This project – executed primarily by Professor Thao Nguyen and Graduate Student Rui Xiao at Johns Hopkins University in support of a DOE/NNSA Presidential Early Career Award in Science and Engineering (PECASE) – developed a theoretical framework for chemothermo- mechanical behavior of amorphous polymers to model the effects of physical aging and solvent-induced environmental factors on their thermoviscoelastic behavior.« less

Physical and mechanical characterisation of 3D-printed porous titanium for biomedical applications.

PubMed

El-Hajje, Aouni; Kolos, Elizabeth C; Wang, Jun Kit; Maleksaeedi, Saeed; He, Zeming; Wiria, Florencia Edith; Choong, Cleo; Ruys, Andrew J

2014-11-01

The elastic modulus of metallic orthopaedic implants is typically 6-12 times greater than cortical bone, causing stress shielding: over time, bone atrophies through decreased mechanical strain, which can lead to fracture at the implantation site. Introducing pores into an implant will lower the modulus significantly. Three dimensional printing (3DP) is capable of producing parts with dual porosity features: micropores by process (residual pores from binder burnout) and macropores by design via a computer aided design model. Titanium was chosen due to its excellent biocompatibility, superior corrosion resistance, durability, osteointegration capability, relatively low elastic modulus, and high strength to weight ratio. The mechanical and physical properties of 3DP titanium were studied and compared to the properties of bone. The mechanical and physical properties were tailored by varying the binder (polyvinyl alcohol) content and the sintering temperature of the titanium samples. The fabricated titanium samples had a porosity of 32.2-53.4% and a compressive modulus of 0.86-2.48 GPa, within the range of cancellous bone modulus. Other physical and mechanical properties were investigated including fracture strength, density, fracture toughness, hardness and surface roughness. The correlation between the porous 3DP titanium-bulk modulus ratio and porosity was also quantified.

NASA Tech Briefs, November 1997. Volume 21, No. 11

NASA Technical Reports Server (NTRS)

1997-01-01

Topics covered include: Test and Measurement; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Software; Mechanics; Machinery/Automation; Books and Reports..

NASA Tech Briefs, August 1992. Volume 16, No. 8

NASA Technical Reports Server (NTRS)

1992-01-01

Topics include: Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

Penguin Fact Sheet.

ERIC Educational Resources Information Center

Flotsam and Jetsam: A Newsletter for Massachusetts Marine Educators, 1985

1985-01-01

Presents factual information on penguins using an outline format. Includes descriptions of physical characteristics, behavioral mechanisms, geographical distribution, and physiological processes. Provides separate bibliographies for teachers and students. (ML)

NASA Tech Briefs, September 1992. Volume 16, No.9

NASA Technical Reports Server (NTRS)

1992-01-01

Topics include: Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, Summer 1985

NASA Technical Reports Server (NTRS)

1985-01-01

Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Life Sciences; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences.

NASA Tech Briefs, January 1993. Volume 17, No. 1

NASA Technical Reports Server (NTRS)

1993-01-01

Topics include: Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences;

NASA Tech Briefs, November 1992. Volume 16, No. 11

NASA Technical Reports Server (NTRS)

1992-01-01

Topics include: Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences;

NASA Tech Briefs, December 1992. Volume 16, No. 12

NASA Technical Reports Server (NTRS)

1992-01-01

Topics include: Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences;

NASA Tech Briefs, Spring 1985

NASA Technical Reports Server (NTRS)

1985-01-01

Topic include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Life Sciences; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences.

Optimization of the Switch Mechanism in a Circuit Breaker Using MBD Based Simulation

PubMed Central

Jang, Jin-Seok; Yoon, Chang-Gyu; Ryu, Chi-Young; Kim, Hyun-Woo; Bae, Byung-Tae; Yoo, Wan-Suk

2015-01-01

A circuit breaker is widely used to protect electric power system from fault currents or system errors; in particular, the opening mechanism in a circuit breaker is important to protect current overflow in the electric system. In this paper, multibody dynamic model of a circuit breaker including switch mechanism was developed including the electromagnetic actuator system. Since the opening mechanism operates sequentially, optimization of the switch mechanism was carried out to improve the current breaking time. In the optimization process, design parameters were selected from length and shape of each latch, which changes pivot points of bearings to shorten the breaking time. To validate optimization results, computational results were compared to physical tests with a high speed camera. Opening time of the optimized mechanism was decreased by 2.3 ms, which was proved by experiments. Switch mechanism design process can be improved including contact-latch system by using this process. PMID:25918740

A broad look at solar physics adapted from the solar physics study of August 1975

NASA Technical Reports Server (NTRS)

Parker, E.; Timothy, A.; Beckers, J.; Hundhausen, A.; Kundu, M. R.; Leith, C. E.; Lin, R.; Linsky, J.; Macdonald, F. B.; Noyes, R.

1979-01-01

The current status of our knowledge of the basic mechanisms involved in fundamental solar phenomena is reviewed. These include mechanisms responsible for heating the corona, the generation of the solar wind, the particle acceleration in flares, and the dissipation of magnetic energy in field reversal regions, known as current sheets. The discussion covers solar flares and high-energy phenomena, solar active regions; solar interior, convection, and activity; the structure and energetics of the quiet solar atmosphere; the structure of the corona; the solar composition; and solar terrestrial interactions. It also covers a program of solar research, including the special observational requirements for spectral and angular resolution, sensitivity, time resolution, and duration of the techniques employed.

East-West paths to unconventional computing.

PubMed

Adamatzky, Andrew; Akl, Selim; Burgin, Mark; Calude, Cristian S; Costa, José Félix; Dehshibi, Mohammad Mahdi; Gunji, Yukio-Pegio; Konkoli, Zoran; MacLennan, Bruce; Marchal, Bruno; Margenstern, Maurice; Martínez, Genaro J; Mayne, Richard; Morita, Kenichi; Schumann, Andrew; Sergeyev, Yaroslav D; Sirakoulis, Georgios Ch; Stepney, Susan; Svozil, Karl; Zenil, Hector

2017-12-01

Unconventional computing is about breaking boundaries in thinking, acting and computing. Typical topics of this non-typical field include, but are not limited to physics of computation, non-classical logics, new complexity measures, novel hardware, mechanical, chemical and quantum computing. Unconventional computing encourages a new style of thinking while practical applications are obtained from uncovering and exploiting principles and mechanisms of information processing in and functional properties of, physical, chemical and living systems; in particular, efficient algorithms are developed, (almost) optimal architectures are designed and working prototypes of future computing devices are manufactured. This article includes idiosyncratic accounts of 'unconventional computing' scientists reflecting on their personal experiences, what attracted them to the field, their inspirations and discoveries. Copyright © 2017 Elsevier Ltd. All rights reserved.

An Integrated Approach to Thermodynamics in the Introductory Physics Course.

ERIC Educational Resources Information Center

Alonso, Marcelo; Finn, Edward J.

1995-01-01

Presents an approach to combine the empirical approach of classical thermodynamics with the structural approach of statistical mechanics. Topics covered include dynamical foundation of the first law; mechanical work, heat, radiation, and the first law; thermal equilibrium; thermal processes; thermodynamic probability; entropy; the second law;…

The use of light emission in failure analysis of CMOS ICs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hawkins, C.F.; Soden, J.M.; Cole, E.I. Jr.

1990-01-01

The use of photon emission for analyzing failure mechanisms and defects in CMOS ICs is presented. Techniques are given for accurate identification and spatial localization of failure mechanisms and physical defects, including defects such as short and open circuits which do not themselves emit photons.

NASA Tech Briefs, September 1995. Volume 19, No. 9

NASA Technical Reports Server (NTRS)

1995-01-01

A special focus for this issue is Sensors. Topics covered include : Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Life Sciences; Mechanics; Machinery; Fabrication Technology; and Mathematics and Information Sciences. A section of Laser Tech Briefs is included.

Research in the aerospace physical sciences

NASA Technical Reports Server (NTRS)

Whitehurst, R. N.

1973-01-01

Research efforts are reported in various areas including dynamics of thin films, polymer chemistry, mechanical and chemical properties of materials, radar system engineering, stabilization of lasers, and radiation damage of organic crystals. Brief summaries of research accomplished and literature citations are included.

Physical biology in cancer. 4. Physical cues guide tumor cell adhesion and migration.

PubMed

Stroka, Kimberly M; Konstantopoulos, Konstantinos

2014-01-15

As tumor cells metastasize from the primary tumor location to a distant secondary site, they encounter an array of biologically and physically heterogeneous microenvironments. While it is well established that biochemical signals guide all stages of the metastatic cascade, mounting evidence indicates that physical cues also direct tumor cell behavior, including adhesion and migration phenotypes. Physical cues acting on tumor cells in vivo include extracellular matrix mechanical properties, dimensionality, and topography, as well as interstitial flow, hydrodynamic shear stresses, and local forces due to neighboring cells. State-of-the-art technologies have recently enabled us and other researchers to engineer cell microenvironments that mimic specific physical properties of the cellular milieu. Through integration of these engineering strategies, along with physics, molecular biology, and imaging techniques, we have acquired new insights into tumor cell adhesion and migration mechanisms. In this review, we focus on the extravasation and invasion stages of the metastatic cascade. We first discuss the physical role of the endothelium during tumor cell extravasation and invasion and how contractility of endothelial and tumor cells contributes to the ability of tumor cells to exit the vasculature. Next, we examine how matrix dimensionality and stiffness coregulate tumor cell adhesion and migration beyond the vasculature. Finally, we summarize how tumor cells translate and respond to physical cues through mechanotransduction. Because of the critical role of tumor cell mechanotransduction at various stages of the metastatic cascade, targeting signaling pathways involved in tumor cell mechanosensing of physical stimuli may prove to be an effective therapeutic strategy for cancer patients.

NASA Tech Briefs, October 1989. Volume 13, No. 10

NASA Technical Reports Server (NTRS)

1989-01-01

Topics include: Electronic Components and Circuits. Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Fabrication Technology, Mathematics and Information Sciences, and Life Sciences

NASA Tech Briefs, February 1990. Volume 14, No. 2

NASA Technical Reports Server (NTRS)

1990-01-01

Topics include: Electronic Components and Circuits. Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Fabrication Technology, Mathematics and Information Sciences, and Life Sciences

NASA Tech Briefs, January 1990. Volume 14, No. 1

NASA Technical Reports Server (NTRS)

1990-01-01

Topics include: Electronic Components and Circuits. Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Fabrication Technology, Mathematics and Information Sciences, and Life Sciences

NASA Tech Briefs, November 1989. Volume 13, No. 11

NASA Technical Reports Server (NTRS)

1989-01-01

Topics include: Electronic Components and Circuits. Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Fabrication Technology, Mathematics and Information Sciences, and Life Sciences

NASA Tech Briefs, September 1989. Volume 13, No. 9

NASA Technical Reports Server (NTRS)

1989-01-01

Topics include: Electronic Components and Circuits. Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Fabrication Technology, Mathematics and Information Sciences, and Life Sciences.

NASA Tech Briefs, October 1992. Volume 16, No. 10

NASA Technical Reports Server (NTRS)

1992-01-01

Topics covered include: Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication technology; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, December 1989. Volume 13, No. 12

NASA Technical Reports Server (NTRS)

1989-01-01

Topics include: Electronic Components and Circuits. Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Fabrication Technology, Mathematics and Information Sciences, and Life Sciences.

NASA Tech Briefs, April 1993. Volume 17, No. 4

NASA Technical Reports Server (NTRS)

1993-01-01

Topics include: Optoelectronics; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences;

NASA Tech Briefs, March 1990. Volume 14, No. 3

NASA Technical Reports Server (NTRS)

1990-01-01

Topics include: Electronic Components and Circuits. Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Fabrication Technology, Mathematics and Information Sciences, and Life Sciences

Protein Modification: A Proposed Mechanism for the Long-Term Pathogenesis of Traumatic Brain Injury

DTIC Science & Technology

2015-06-04

two distinct phases: a first stage of “primary injury,” and subsequent “secondary injury.” Primary injury refers to the direct, physical disruption of...acid, is due to a number of post- injury effects, including the physical disruption of cell membranes and the impairment of energy-dependent...TBI. The pathophysiology of TBI is both complex and dynamic, involving physical injury, ischemia/reperfusion, hypoxia, glutamate excitotoxicity

Clinical and laboratory evaluation of microstructural changes in the physical, mechanical and chemical properties of dental filling materials under the influence of an electromagnetic field.

PubMed

Moiseeva, Natalia S; Kunin, Anatoly A

2018-03-01

Restorative filling materials used for dental caries prevention and treatment consist of various components including monomers or oligomers, which play a significant role in forming the main structure of these materials, as well as in characterising their physical, mechanical and chemical properties. The necessity for the development and improvement of structural characteristics of polymeric dental filling materials intended for caries prevention and their life duration increase served as the initiating factor of our research. According to the research purpose and challenges, we studied the changes in the physical, mechanical and chemical properties of composite filling materials with and without electromagnetic field influence. The investigations in vivo include the study of microstructural features of polymeric filling materials by scanning electron microscopy (SEM) and the investigations in vitro include the study of sealed and extracted human teeth chips by using X-ray spectral analysis. We also evaluated the changes in the strength characteristics of dental filling materials with and without electromagnetic field influence. The analysis of the obtained data indicates the presence of structural changes in polymeric dental filling materials, including the material microstructure condensation confirmed by the SEM results, an increase in the strength and adhesion characteristics and certain regularities of the chemical elemental composition concentration change in the area of hard tooth tissue and dental filling material. These scientific data will provide tooth caries prevention and promote the increase of treatment quality.

Technical accomplishments of the NASA Lewis Research Center, 1989

NASA Technical Reports Server (NTRS)

1990-01-01

Topics addressed include: high-temperature composite materials; structural mechanics; fatigue life prediction for composite materials; internal computational fluid mechanics; instrumentation and controls; electronics; stirling engines; aeropropulsion and space propulsion programs, including a study of slush hydrogen; space power for use in the space station, in the Mars rover, and other applications; thermal management; plasma and radiation; cryogenic fluid management in space; microgravity physics; combustion in reduced gravity; test facilities and resources.

Quantum Optical Implementations of Current Quantum Computing Paradigms

DTIC Science & Technology

2005-05-01

Conferences and Proceedings: The results were presented at several conferences. These include: 1. M. O. Scully, " Foundations of Quantum Mechanics ", in...applications have revealed a strong connection between the fundamental aspects of quantum mechanics that governs physical systems and the informational...could be solved in polynomial time using quantum computers. Another set of problems where quantum mechanics can carry out computations substantially

Are biomechanical factors, meniscal pathology, and physical activity risk factors for bone marrow lesions at the knee? A systematic review.

PubMed

Lim, Yuan Z; Wang, Yuanyuan; Wluka, Anita E; Davies-Tuck, Miranda L; Teichtahl, Andrew; Urquhart, Donna M; Cicuttini, Flavia M

2013-10-01

To systematically review the literature to determine whether biomechanical factors, meniscal pathology, and physical activity are risk factors for bone marrow lesions (BMLs) at the knee identified from magnetic resonance imaging in pre-osteoarthritis and osteoarthritis populations. Electronic searches of MEDLINE and EMBASE were performed from January 1, 1996 to October 31, 2012 using the keywords of bone marrow lesion(s), bone marrow (o)edema, osteoarthritis, and knee. Studies examining biomechanical factors, meniscal pathology, or physical activity in relation to the presence, incidence, or change in BMLs at the knee were included. Two independent reviewers extracted the data and assessed the methodological quality of selected studies. Due to the heterogeneity of the studies, we performed a best evidence synthesis. Fifteen studies were included in this review, of which 9 were considered high quality. The study populations were heterogeneous in terms of the symptoms and radiographic knee osteoarthritis. There was strong evidence for relationships of mechanical knee alignment and meniscal pathology with BMLs in osteoarthritis populations. There was a paucity of evidence for a relationship between physical activity and BMLs. Despite the heterogeneity of included studies, these data suggest that mechanical knee alignment and meniscal pathology are risk factors for BMLs in knee osteoarthritis. It suggests that BMLs in individuals with osteoarthritis are more susceptible to mechanical knee alignment. Given the role of BMLs in the pathogenesis of knee osteoarthritis, identifying strategies to modify these risk factors will be important in slowing the progression and reducing the burden of knee osteoarthritis. Copyright © 2013 Elsevier Inc. All rights reserved.

NASA Tech Briefs, January 1989. Volume 13, No. 1

NASA Technical Reports Server (NTRS)

1989-01-01

Topics include: Electronic Components & and Circuits. Electronic Systems, A Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Fabrication Technology, Mathematics and Information Sciences, and Life Sciences.

NASA Tech Briefs, June 1993. Volume 17, No. 6

NASA Technical Reports Server (NTRS)

1993-01-01

Topics include: Imaging Technology: Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, February 1993. Volume 17, No. 2

NASA Technical Reports Server (NTRS)

1993-01-01

Topics include: Communication Technology; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, April 1992. Volume 16, No. 4

NASA Technical Reports Server (NTRS)

1992-01-01

Topics covered include: New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences.

Method and apparatus for separating material

DOEpatents

Oder, Robin R.; Jamison, Russell E.

2004-11-23

An apparatus for sorting particles composed of a mixture of particles with differing physical and chemical characteristics. The apparatus includes a comminutor or a pulverizer for reducing the size of the particles. The apparatus includes a mechanism for separating undesired material from desired material.

The physical hydrogeology of ore deposits

USGS Publications Warehouse

Ingebritsen, Steven E.; Appold, M.S.

2012-01-01

Hydrothermal ore deposits represent a convergence of fluid flow, thermal energy, and solute flux that is hydrogeologically unusual. From the hydrogeologic perspective, hydrothermal ore deposition represents a complex coupled-flow problem—sufficiently complex that physically rigorous description of the coupled thermal (T), hydraulic (H), mechanical (M), and chemical (C) processes (THMC modeling) continues to challenge our computational ability. Though research into these coupled behaviors has found only a limited subset to be quantitatively tractable, it has yielded valuable insights into the workings of hydrothermal systems in a wide range of geologic environments including sedimentary, metamorphic, and magmatic. Examples of these insights include the quantification of likely driving mechanisms, rates and paths of fluid flow, ore-mineral precipitation mechanisms, longevity of hydrothermal systems, mechanisms by which hydrothermal fluids acquire their temperature and composition, and the controlling influence of permeability and other rock properties on hydrothermal fluid behavior. In this communication we review some of the fundamental theory needed to characterize the physical hydrogeology of hydrothermal systems and discuss how this theory has been applied in studies of Mississippi Valley-type, tabular uranium, porphyry, epithermal, and mid-ocean ridge ore-forming systems. A key limitation in the computational state-of-the-art is the inability to describe fluid flow and transport fully in the many ore systems that show evidence of repeated shear or tensional failure with associated dynamic variations in permeability. However, we discuss global-scale compilations that suggest some numerical constraints on both mean and dynamically enhanced crustal permeability. Principles of physical hydrogeology can be powerful tools for investigating hydrothermal ore formation and are becoming increasingly accessible with ongoing advances in modeling software.

Using Community Insight to Understand Physical Activity Adoption in Overweight and Obese African American and Hispanic Women: A Qualitative Study

ERIC Educational Resources Information Center

Mama, Scherezade K.; McCurdy, Sheryl A.; Evans, Alexandra E.; Thompson, Deborah I.; Diamond, Pamela M.; Lee, Rebecca E.

2015-01-01

Ecologic models suggest that multiple levels of influencing factors are important for determining physical activity participation and include individual, social, and environmental factors. The purpose of this qualitative study was to use an ecologic framework to gain a deeper understanding of the underlying behavioral mechanisms that influence…

Phase B: Final definition and preliminary design study for the initial Atmospheric Cloud Physics Laboratory (ACPL): A spacelab mission payload. Final review (DR-MA-03)

NASA Technical Reports Server (NTRS)

Clausen, O. W.

1976-01-01

Systems design for an initial atmospheric cloud physics laboratory to study microphysical processes in zero gravity is presented. Included are descriptions of the fluid, thermal, mechanical, control and data, and electrical distribution interfaces with Spacelab. Schedule and cost analysis are discussed.

Investigations into the Power MOSFET SEGR Phenomenon and its Physical Mechanism

NASA Technical Reports Server (NTRS)

Swift, G. M.; Edmonds, L. E.; Miyahira, T.; Nichols, D. K.; Johnston, A. H.

1997-01-01

The state of understanding of the destructive SEGR event in power MOSFETs is relatively mature with large published efforts, both experimental and theoretical. However, gasps remain in the uderstanding of the phenomenon, including unexplained anomalies, emperical-only dependencies on some important device and incident ion physical parameters, and limited insight into latent effets.

The Physics of Living in Space: A Physicist's Attempt to Provide Science and Engineering Education for Non-Science Students.

ERIC Educational Resources Information Center

Holbrow, C. H.

1983-01-01

A course was developed to teach physics concepts and to help students understand mathematics, the nature and role of engineers and engineering in society, and to distinguish between science/technology from pseudo-science. Includes course goals/content, mechanics, start-up, and long-term projects. (JN)

The ambiguous role of the paraeducator in the general physical education environment.

PubMed

Bryan, Rebecca R; McCubbin, Jeffrey A; van der Mars, Hans

2013-04-01

The use of paraeducators has increased as a main mechanism to include more students with disabilities in the public schools in the U.S. Although the utilization of paraeducators is intended to be a supportive service delivery option, many concerns and challenges have resulted. The purpose of this study was to examine the role of the paraeducator in the general physical education environment from the perspectives of special education, physical education, and adapted physical education teachers and paraeducators. Data were collected from a phenomenological approach using questionnaires, interviews, and observations. Results indicate concerns about the clarity of the role of the paraeducator in physical education. Emerging themes include elastic definitions of student protection and teacher backup, contradictory expectations and mixed acceptance, and paraeducators' role ambiguity. Findings regarding the role of the paraeducator are essential in determining both best practice and legal policy for the appropriate utilization of paraeducators in physical education.

Incidental movement, lifestyle-embedded activity and sleep: new frontiers in physical activity assessment.

PubMed

Tremblay, Mark S; Esliger, Dale W; Tremblay, Angelo; Colley, Rachel

2007-01-01

Canadian public health messages relating to physical activity have historically focused on the prescription of purposeful exercise, most often assessing leisure-time physical activity (LTPA). Although LTPA contributes to total energy expenditure (TEE), a large part of the day remains neglected unless one also considers the energy expended outside of purposeful exercise. This paper reviews the potential impact of incidental (non-exercise or non-purposeful) physical activity and lifestyle-embedded activities (chores and incidental walking) upon TEE and indicators of health. Given that incidental movement occurs sporadically throughout the day, this form of energy expenditure is perhaps most vulnerable to increasingly ubiquitous mechanization and automation. The paper also explores the relationship of physical inactivity, including sleep, to physical activity, TEE, and health outcomes. Suggestions are provided for a more comprehensive physical activity recommendation that includes all components of TEE. Objective physical activity monitors with time stamps are considered as a better means to capture and examine human movements over the entire day.

NASA Tech Briefs, January 1992. Volume 16, No. 1

NASA Technical Reports Server (NTRS)

1992-01-01

Topics include: New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Fabrication; Mathematics and Information Sciences; Life Sciences;

NASA Tech Briefs, May 1992. Volume 16, No. 5

NASA Technical Reports Server (NTRS)

1992-01-01

Topics include: New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, July 1992. Volume 16, No. 7

NASA Technical Reports Server (NTRS)

1992-01-01

Topics include: New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, March 1992. Volume 16, No. 3

NASA Technical Reports Server (NTRS)

1992-01-01

Topics include: New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, September 1997. Volume 21, No. 9

NASA Technical Reports Server (NTRS)

1997-01-01

Topics include: Data Acquisition and Analysis; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Software; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences.

The alloy with a memory, 55-Nitinol: Its physical metallurgy, properties, and applications

NASA Technical Reports Server (NTRS)

Jackson, C. M.; Wagner, H. J.; Wasilewski, R. J.

1972-01-01

A series of nickel titanium alloys (55-Nitinol), which are unique in that they possess a shape memory, are described. Components made of these materials that are altered in their shapes by deformation under proper conditions return to predetermined shapes when they are heated to the proper temperature range. The shape memory, together with the force exerted and the ability of the material to do mechanical work as it returns to its predetermined shape, suggest a wide variety of industrial applications for the alloy. Also included are discussions of the physical metallurgy and the mechanical, physical, and chemical properties of 55-Nitinol; procedures for melting and processing the material into useful shapes; and a summary of applications.

Wave-Particle Interactions As a Driving Mechanism for the Solar Wind

NASA Technical Reports Server (NTRS)

Wagner, William J.

2004-01-01

Our research has been focusing on a highly experimentally relevant issue: intermittency of the fluctuating fields in outflowing plasmas. We have contributed to both the theoretical and experimental research of the topic. In particular, we have developed a theoretical model and data analyzing programs to examine the issue of intermittency in space plasma outflows, including the solar wind. As fluctuating electric fields in the solar wind are likely to provide a heating and acceleration mechanism for the ions, our studies of the intermittency in turbulence in space plasma outflows help us toward achieving the goal of comparing major physical mechanisms that contribute to the driving of the fast solar wind. Our new theoretical model extends the utilities of our global hybrid model, which has allowed us to follow the kinetic evolution of the particle distributions along an inhomogeneous field line while the particles are subjected to various physical mechanisms. The physical effects that were considered in the global hybrid model included wave-particle interactions, an ambipolar electric field that was consistent with the particle distributions themselves, and Coulomb collisions. With an earlier version of the global hybrid model, we examined the overall impact on the solar wind flow due to the combination of these physical effects. In particular, we studied the combined effects of two major mechanisms that had been proposed as the drivers of the fast solar wind: (1) velocity filtration effect due to suprathermal electrons; (2) ion cyclotron resonance. Since the approval of this research grant, we have updated the model such that the effects due to these two driving mechanisms can be examined separately, thereby allowing us to compare their contributions to the acceleration of the solar wind. In the next section, we shall demonstrate that the velocity filtration effect is rather insignificant in comparison with that due to ion cyclotron resonance.

Challenges in Teaching the Mechanics of Breathing to Medical and Graduate Students

ERIC Educational Resources Information Center

West, John B.

2008-01-01

The mechanics of breathing has always been a difficult topic for some medical and graduate students. The subject is very quantitative and contains a number of concepts that some students have trouble with, including physical principles such as pressure, flow, volume, resistance, elasticity, and compliance. Apparently, present-day students find the…

Chem I Supplement: Bee Sting: The Chemistry of an Insect Venom.

ERIC Educational Resources Information Center

O'Connor, Rod; Peck, Larry

1980-01-01

Considers various aspects of bee stings including the physical mechanism of the venom apparatus in the bee, categorization of physiological responses of nonprotected individuals to bee sting, chemical composition of bee venom and the mechanisms of venom action, and areas of interest in the synthesis of bee venom. (CS)

On-the-go mapping of soil mechanical resistance using a linear depth effect model.

USDA-ARS?s Scientific Manuscript database

An instrumented blade sensor was developed to map soil mechanical resistance as well as its change with depth. The sensor has become a part of the Integrated Soil Physical Properties Mapping System (ISPPMS), which also includes an optical and a capacitor-based sensor. The instrumented blade of the...

Cyclic Polyynes as Examples of the Quantum Mechanical Particle on a Ring

ERIC Educational Resources Information Center

Anderson, Bruce D.

2012-01-01

Many quantum mechanical models are discussed as part of the undergraduate physical chemistry course to help students understand the connection between eigenvalue expressions and spectroscopy. Typical examples covered include the particle in a box, the harmonic oscillator, the rigid rotor, and the hydrogen atom. This article demonstrates that…

Closed-form solutions for linear regulator design of mechanical systems including optimal weighting matrix selection

NASA Technical Reports Server (NTRS)

Hanks, Brantley R.; Skelton, Robert E.

1991-01-01

Vibration in modern structural and mechanical systems can be reduced in amplitude by increasing stiffness, redistributing stiffness and mass, and/or adding damping if design techniques are available to do so. Linear Quadratic Regulator (LQR) theory in modern multivariable control design, attacks the general dissipative elastic system design problem in a global formulation. The optimal design, however, allows electronic connections and phase relations which are not physically practical or possible in passive structural-mechanical devices. The restriction of LQR solutions (to the Algebraic Riccati Equation) to design spaces which can be implemented as passive structural members and/or dampers is addressed. A general closed-form solution to the optimal free-decay control problem is presented which is tailored for structural-mechanical system. The solution includes, as subsets, special cases such as the Rayleigh Dissipation Function and total energy. Weighting matrix selection is a constrained choice among several parameters to obtain desired physical relationships. The closed-form solution is also applicable to active control design for systems where perfect, collocated actuator-sensor pairs exist.

Quantum physics in neuroscience and psychology: A neurophysicalmodel of the mind/brain interaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwartz, Jeffrey M.; Stapp, Henry P.; Beauregard, Mario

Neuropsychological research on the neural basis of behavior generally posits that brain mechanisms will ultimately suffice to explain all psychologically described phenomena. This assumption stems from the idea that the brain is made up entirely of material particles and fields, and that all causal mechanisms relevant to neuroscience can therefore be formulated solely in terms of properties of these elements. Thus terms having intrinsic mentalistic and/or experiential content (e.g., ''feeling,'' ''knowing,'' and ''effort'') are not included as primary causal factors. This theoretical restriction is motivated primarily by ideas about the natural world that have been known to be fundamentally incorrectmore » for more than three quarters of a century. Contemporary basic physical theory differs profoundly from classical physics on the important matter of how the consciousness of human agents enters into the structure of empirical phenomena. The new principles contradict the older idea that local mechanical processes alone can account for the structure of all observed empirical data. Contemporary physical theory brings directly and irreducibly into the overall causal structure certain psychologically described choices made by human agents about how they will act. This key development in basic physical theory is applicable to neuroscience, and it provides neuroscientists and psychologists with an alternative conceptual framework for describing neural processes. Indeed, due to certain structural features of ion channels critical to synaptic function, contemporary physical theory must in principle be used when analyzing human brain dynamics. The new framework, unlike its classical-physics-based predecessor is erected directly upon, and is compatible with, the prevailing principles of physics, and is able to represent more adequately than classical concepts the neuroplastic mechanisms relevant to the growing number of empirical studies of the capacity of directed attention and mental effort to systematically alter brain function.« less

Quantum physics in neuroscience and psychology: a neurophysical model of mind–brain interaction

PubMed Central

Schwartz, Jeffrey M; Stapp, Henry P; Beauregard, Mario

2005-01-01

Neuropsychological research on the neural basis of behaviour generally posits that brain mechanisms will ultimately suffice to explain all psychologically described phenomena. This assumption stems from the idea that the brain is made up entirely of material particles and fields, and that all causal mechanisms relevant to neuroscience can therefore be formulated solely in terms of properties of these elements. Thus, terms having intrinsic mentalistic and/or experiential content (e.g. ‘feeling’, ‘knowing’ and ‘effort’) are not included as primary causal factors. This theoretical restriction is motivated primarily by ideas about the natural world that have been known to be fundamentally incorrect for more than three-quarters of a century. Contemporary basic physical theory differs profoundly from classic physics on the important matter of how the consciousness of human agents enters into the structure of empirical phenomena. The new principles contradict the older idea that local mechanical processes alone can account for the structure of all observed empirical data. Contemporary physical theory brings directly and irreducibly into the overall causal structure certain psychologically described choices made by human agents about how they will act. This key development in basic physical theory is applicable to neuroscience, and it provides neuroscientists and psychologists with an alternative conceptual framework for describing neural processes. Indeed, owing to certain structural features of ion channels critical to synaptic function, contemporary physical theory must in principle be used when analysing human brain dynamics. The new framework, unlike its classic-physics-based predecessor, is erected directly upon, and is compatible with, the prevailing principles of physics. It is able to represent more adequately than classic concepts the neuroplastic mechanisms relevant to the growing number of empirical studies of the capacity of directed attention and mental effort to systematically alter brain function. PMID:16147524

Physical approaches to biomaterial design

PubMed Central

Mitragotri, Samir; Lahann, Joerg

2009-01-01

The development of biomaterials for drug delivery, tissue engineering and medical diagnostics has traditionally been based on new chemistries. However, there is growing recognition that the physical as well as the chemical properties of materials can regulate biological responses. Here, we review this transition with regard to selected physical properties including size, shape, mechanical properties, surface texture and compartmentalization. In each case, we present examples demonstrating the significance of these properties in biology. We also discuss synthesis methods and biological applications for designer biomaterials, which offer unique physical properties. PMID:19096389

The physics of proton therapy.

PubMed

Newhauser, Wayne D; Zhang, Rui

2015-04-21

The physics of proton therapy has advanced considerably since it was proposed in 1946. Today analytical equations and numerical simulation methods are available to predict and characterize many aspects of proton therapy. This article reviews the basic aspects of the physics of proton therapy, including proton interaction mechanisms, proton transport calculations, the determination of dose from therapeutic and stray radiations, and shielding design. The article discusses underlying processes as well as selected practical experimental and theoretical methods. We conclude by briefly speculating on possible future areas of research of relevance to the physics of proton therapy.

The physics of proton therapy

PubMed Central

Newhauser, Wayne D; Zhang, Rui

2015-01-01

The physics of proton therapy has advanced considerably since it was proposed in 1946. Today analytical equations and numerical simulation methods are available to predict and characterize many aspects of proton therapy. This article reviews the basic aspects of the physics of proton therapy, including proton interaction mechanisms, proton transport calculations, the determination of dose from therapeutic and stray radiations, and shielding design. The article discusses underlying processes as well as selected practical experimental and theoretical methods. We conclude by briefly speculating on possible future areas of research of relevance to the physics of proton therapy. PMID:25803097

Physics of the Atmosphere

NASA Astrophysics Data System (ADS)

Caballero, Rodrigo

2014-11-01

With the increasing attention paid to climate change, there is ever-growing interest in atmospheric physics and the processes by which the atmosphere affects Earth's energy balance. This self-contained text, written for advanced undergraduate and graduate students in physics or meteorology, assumes no prior knowledge apart from basic mechanics and calculus and contains material for a complete course. Augmented with worked examples, the text considers all aspects of atmospheric physics except dynamics, including moist thermodynamics, cloud microphysics, atmospheric radiation and remote sensing, and will be an invaluable resource for students and researchers.

From classical to quantum mechanics: ``How to translate physical ideas into mathematical language''

NASA Astrophysics Data System (ADS)

Bergeron, H.

2001-09-01

Following previous works by E. Prugovečki [Physica A 91A, 202 (1978) and Stochastic Quantum Mechanics and Quantum Space-time (Reidel, Dordrecht, 1986)] on common features of classical and quantum mechanics, we develop a unified mathematical framework for classical and quantum mechanics (based on L2-spaces over classical phase space), in order to investigate to what extent quantum mechanics can be obtained as a simple modification of classical mechanics (on both logical and analytical levels). To obtain this unified framework, we split quantum theory in two parts: (i) general quantum axiomatics (a system is described by a state in a Hilbert space, observables are self-adjoints operators, and so on) and (ii) quantum mechanics proper that specifies the Hilbert space as L2(Rn); the Heisenberg rule [pi,qj]=-iℏδij with p=-iℏ∇, the free Hamiltonian H=-ℏ2Δ/2m and so on. We show that general quantum axiomatics (up to a supplementary "axiom of classicity") can be used as a nonstandard mathematical ground to formulate physical ideas and equations of ordinary classical statistical mechanics. So, the question of a "true quantization" with "ℏ" must be seen as an independent physical problem not directly related with quantum formalism. At this stage, we show that this nonstandard formulation of classical mechanics exhibits a new kind of operation that has no classical counterpart: this operation is related to the "quantization process," and we show why quantization physically depends on group theory (the Galilei group). This analytical procedure of quantization replaces the "correspondence principle" (or canonical quantization) and allows us to map classical mechanics into quantum mechanics, giving all operators of quantum dynamics and the Schrödinger equation. The great advantage of this point of view is that quantization is based on concrete physical arguments and not derived from some "pure algebraic rule" (we exhibit also some limit of the correspondence principle). Moreover spins for particles are naturally generated, including an approximation of their interaction with magnetic fields. We also recover by this approach the semi-classical formalism developed by E. Prugovečki [Stochastic Quantum Mechanics and Quantum Space-time (Reidel, Dordrecht, 1986)].

NASA Tech Briefs, Spring 1976. Volume 1, No. 1

NASA Technical Reports Server (NTRS)

1976-01-01

Topics covered include : Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Life Sciences; Mechanics; Machinery; Fabrication Technology; and Mathematics and Information Sciences. Also included are NEW PRODUCT IDEAS: A summary of selected innovations of value to manufacturers for the development of new products.

LASER Tech Briefs, Winter 1994. Volume 2, No. 1

NASA Technical Reports Server (NTRS)

Schnirring, Bill (Editor)

1994-01-01

Topics include: Electronic Components and Circuits. Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Fabrication Technology, Mathematics and Information Sciences, Life Sciences, and Books and reports

NASA Tech Briefs, May 1993. Volume 17, No. 5

NASA Technical Reports Server (NTRS)

1993-01-01

Topics include: Advanced Composites and Plastics; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

LASER Tech Briefs, February 1995. Volume 3, No. 1

NASA Technical Reports Server (NTRS)

1995-01-01

Topics included in this issue of LASER Tech Briefs are: Electronic Components and Circuits. Electronic Systems, Physical Sciences, Materials, Mechanics, Fabrication, and Mathematics and Information Sciences, and

NASA Tech Briefs, February 1992. Volume 16, No. 2

NASA Technical Reports Server (NTRS)

1992-01-01

Topics covered include: New Product Development; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, Fall 1985. Volume 9, No. 3

NASA Technical Reports Server (NTRS)

1985-01-01

Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Life Sciences Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences.

NASA Tech Briefs, September 2000. Volume 24, No. 9

NASA Technical Reports Server (NTRS)

2000-01-01

Topics include: Sensors; Test and Measurement; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Bio-Medical; semiconductors/ICs; Books and Reports.

Advantages and Disadvantages of Aquatic Plant Management Techniques

DTIC Science & Technology

2000-09-01

This report provides an overview of the environmental and practical advantages and disadvantages of the major aquatic plant management methods, including biological, chemical, mechanical, and physical control techniques.

NASA Tech Briefs, July 1993. Volume 17, No. 7

NASA Technical Reports Server (NTRS)

1993-01-01

Topics include: Data Acquisition and Analysis: Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, June 1992. Volume 16, No. 6

NASA Technical Reports Server (NTRS)

1992-01-01

Topics covered include: New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, January 1995. Volume 19, No. 1

NASA Technical Reports Server (NTRS)

1995-01-01

Topics include: Sensors; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences; Books and Reports

NASA Tech Briefs, April 1988. Volume 12, No. 4

NASA Technical Reports Server (NTRS)

1988-01-01

Topics include: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences.

If Only Newton Had a Rocket.

ERIC Educational Resources Information Center

Hammock, Frank M.

1988-01-01

Shows how model rocketry can be included in physics curricula. Describes rocket construction, a rocket guide sheet, calculations and launch teams. Discusses the relationships of basic mechanics with rockets. (CW)

NASA Tech Briefs, July 1989. Volume 13, No. 7

NASA Technical Reports Server (NTRS)

1989-01-01

Topics include New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials;;Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences.

Bio-chemo-mechanical models of vascular mechanics

PubMed Central

Kim, Jungsil; Wagenseil, Jessica E.

2014-01-01

Models of vascular mechanics are necessary to predict the response of an artery under a variety of loads, for complex geometries, and in pathological adaptation. Classic constitutive models for arteries are phenomenological and the fitted parameters are not associated with physical components of the wall. Recently, microstructurally-linked models have been developed that associate structural information about the wall components with tissue-level mechanics. Microstructurally-linked models are useful for correlating changes in specific components with pathological outcomes, so that targeted treatments may be developed to prevent or reverse the physical changes. However, most treatments, and many causes, of vascular disease have chemical components. Chemical signaling within cells, between cells, and between cells and matrix constituents affects the biology and mechanics of the arterial wall in the short- and long-term. Hence, bio-chemo-mechanical models that include chemical signaling are critical for robust models of vascular mechanics. This review summarizes bio-mechanical and bio-chemo-mechanical models with a focus on large elastic arteries. We provide applications of these models and challenges for future work. PMID:25465618

Thrust chamber life prediction. Volume 1: Mechanical and physical properties of high performance rocket nozzle materials

NASA Technical Reports Server (NTRS)

Esposito, J. J.; Zabora, R. F.

1975-01-01

Pertinent mechanical and physical properties of six high conductivity metals were determined. The metals included Amzirc, NARloy Z, oxygen free pure copper, electroformed copper, fine silver, and electroformed nickel. Selection of these materials was based on their possible use in high performance reusable rocket nozzles. The typical room temperature properties determined for each material included tensile ultimate strength, tensile yield strength, elongation, reduction of area, modulus of elasticity, Poisson's ratio, density, specific heat, thermal conductivity, and coefficient of thermal expansion. Typical static tensile stress-strain curves, cyclic stress-strain curves, and low-cycle fatigue life curves are shown. Properties versus temperature are presented in graphical form for temperatures from 27.6K (-410 F) to 810.9K (1000 F).

Assessment of the foot and ankle in elite athletes.

PubMed

Schon, Lew C

2009-06-01

An accurate assessment of the foot and ankle problem in elite athletes is the foundation of a treatment plan and prognosis. The special pressures of professional sports, where managers, agents, and lawyers may be involved, makes a thorough assessment especially critical for sound decision-making. Evaluation includes taking a history of the acute and chronic condition, including mechanism, physical sensation at injury, compensatory stresses, and general medical review. The athlete is assessed physically in several different ways, including comprehensive focal examination and alignment in static and dynamic nonweight-bearing and weight-bearing modes. This comprehensive process is essential to accurate assessment.

An Introduction to Quantum Theory

NASA Astrophysics Data System (ADS)

Greensite, Jeff

2017-02-01

Written in a lucid and engaging style, the author takes readers from an overview of classical mechanics and the historical development of quantum theory through to advanced topics. The mathematical aspects of quantum theory necessary for a firm grasp of the subject are developed in the early chapters, but an effort is made to motivate that formalism on physical grounds. Including animated figures and their respective Mathematica® codes, this book provides a complete and comprehensive text for students in physics, maths, chemistry and engineering needing an accessible introduction to quantum mechanics. Supplementary Mathematica codes available within Book Information

Influence of DAD-TA temperature-reducing additive on physical and mechanical properties of bitumen and compaction of asphalt concrete.

NASA Astrophysics Data System (ADS)

Yadykina, V. V.; Akimov, A. E.; Trautvain, A. I.; Kholopov, V. S.

2018-03-01

The paper is devoted to the use of DAD-TA temperature-reducing additive for the preparation and pouring of asphalt concrete mixes at reduced temperatures. It also shows positive influence of the modified bitumen on the efficiency of organo-mineral composite compaction at reduced temperatures. Physical and mechanical properties of asphalt concrete with the use of bitumen modified by DAD-TA additive including indicators characterizing road surfacing life are presented. Arguments to use this material from the point of view of its production technology and environmental impact are given.

Classical Electrodynamics: Lecture notes

NASA Astrophysics Data System (ADS)

Likharev, Konstantin K.

2018-06-01

Essential Advanced Physics is a series comprising four parts: Classical Mechanics, Classical Electrodynamics, Quantum Mechanics and Statistical Mechanics. Each part consists of two volumes, Lecture notes and Problems with solutions, further supplemented by an additional collection of test problems and solutions available to qualifying university instructors. This volume, Classical Electrodynamics: Lecture notes is intended to be the basis for a two-semester graduate-level course on electricity and magnetism, including not only the interaction and dynamics charged point particles, but also properties of dielectric, conducting, and magnetic media. The course also covers special relativity, including its kinematics and particle-dynamics aspects, and electromagnetic radiation by relativistic particles.

NASA Tech Briefs, August 1998. Volume 22, No. 8

NASA Technical Reports Server (NTRS)

1998-01-01

Topics include: special coverage of medical design, electronic components and circuits, electronic systems, software, materials, mechanics, machinery/automation, physical sciences, and a special section of Photonics Tech Briefs.

NASA Tech Briefs, August 1993. Volume 17, No. 8

NASA Technical Reports Server (NTRS)

1993-01-01

Topics include: Computer Graphics; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences; Books and Reports.

NASA Tech Briefs, September 1993. Volume 17, No. 9

NASA Technical Reports Server (NTRS)

1993-01-01

Topics include: Microelectronics; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports.

NASA Tech Briefs, September 1999. Volume 23, No. 9

NASA Technical Reports Server (NTRS)

1999-01-01

Topics discussed include: Computer-Aided Design and Engineering; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences;

NASA Tech Briefs, Winter 1985. Volume 9, No. 4

NASA Technical Reports Server (NTRS)

1985-01-01

Topics covered include: NASA TU Services; New Product Ideas; Electronic Components and Circuits;Electronic Systems; Physical Sciences; Materials; Life Sciences; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences.

NASA Tech Briefs, March 1993. Volume 17, No. 3

NASA Technical Reports Server (NTRS)

1993-01-01

Topics include: Computer-Aided Design and Engineering; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences;

NASA Tech Briefs, January 1994. Volume 18, No. 1

NASA Technical Reports Server (NTRS)

1994-01-01

Topics include: Communications Technology; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences; Books and Reports.

NASA Tech Briefs, January/February 1986. Volume 10, No. 1

NASA Technical Reports Server (NTRS)

1986-01-01

Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Life Sciences; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences.

Mesenchymal stem cell mechanobiology and emerging experimental platforms

PubMed Central

MacQueen, Luke; Sun, Yu; Simmons, Craig A.

2013-01-01

Experimental control over progenitor cell lineage specification can be achieved by modulating properties of the cell's microenvironment. These include physical properties of the cell adhesion substrate, such as rigidity, topography and deformation owing to dynamic mechanical forces. Multipotent mesenchymal stem cells (MSCs) generate contractile forces to sense and remodel their extracellular microenvironments and thereby obtain information that directs broad aspects of MSC function, including lineage specification. Various physical factors are important regulators of MSC function, but improved understanding of MSC mechanobiology requires novel experimental platforms. Engineers are bridging this gap by developing tools to control mechanical factors with improved precision and throughput, thereby enabling biological investigation of mechanics-driven MSC function. In this review, we introduce MSC mechanobiology and review emerging cell culture platforms that enable new insights into mechanobiological control of MSCs. Our main goals are to provide engineers and microtechnology developers with an up-to-date description of MSC mechanobiology that is relevant to the design of experimental platforms and to introduce biologists to these emerging platforms. PMID:23635493

Ultrasonic evaluation of the physical and mechanical properties of granites.

PubMed

Vasconcelos, G; Lourenço, P B; Alves, C A S; Pamplona, J

2008-09-01

Masonry is the oldest building material that survived until today, being used all over the world and being present in the most impressive historical structures as an evidence of spirit of enterprise of ancient cultures. Conservation, rehabilitation and strengthening of the built heritage and protection of human lives are clear demands of modern societies. In this process, the use of nondestructive methods has become much common in the diagnosis of structural integrity of masonry elements. With respect to the evaluation of the stone condition, the ultrasonic pulse velocity is a simple and economical tool. Thus, the central issue of the present paper concerns the evaluation of the suitability of the ultrasonic pulse velocity method for describing the mechanical and physical properties of granites (range size between 0.1-4.0 mm and 0.3-16.5 mm) and for the assessment of its weathering state. The mechanical properties encompass the compressive and tensile strength and modulus of elasticity, and the physical properties include the density and porosity. For this purpose, measurements of the longitudinal ultrasonic pulse velocity with distinct natural frequency of the transducers were carried out on specimens with different size and shape. A discussion of the factors that induce variations on the ultrasonic velocity is also provided. Additionally, statistical correlations between ultrasonic pulse velocity and mechanical and physical properties of granites are presented and discussed. The major output of the work is the confirmation that ultrasonic pulse velocity can be effectively used as a simple and economical nondestructive method for a preliminary prediction of mechanical and physical properties, as well as a tool for the assessment of the weathering changes of granites that occur during the serviceable life. This is of much interest due to the usual difficulties in removing specimens for mechanical characterization.

Evaluation of thermal, chemical, and mechanical seed scarification methods for 4 Great Basin lupine species

Treesearch

Covy D. Jones; Mikel R. Stevens; Von D. Jolley; Bryan G. Hopkins; Scott L. Jensen; Dave Turner; Jason M. Stettler

2016-01-01

Seeds of most Great Basin lupine (Lupinus spp. [Fabaceae]) species are physically dormant and thus, difficult to establish in uniform stands in seed production fields. We designed this study to examine 5 seed scarification techniques, each with 11 levels of application (including a non-scarified control), to reduce the physical seed dormancy of longspur lupine...

Investigating the applicability of activity-based quantum mechanics in a few high school physics classrooms

NASA Astrophysics Data System (ADS)

Escalada, Lawrence Todd

Quantum physics is not traditionally introduced in high school physics courses because of the level of abstraction and mathematical formalism associated with the subject. As part of the Visual Quantum Mechanics project, activity-based instructional units have been developed that introduce quantum principles to students who have limited backgrounds in physics and mathematics. This study investigates the applicability of one unit, Solids & Light, that introduces quantum principles within the context of learning about light emitting diodes. An observation protocol, attitude surveys, and questionnaires were used to examine the implementation of materials and student-teacher interactions in various secondary physics classrooms. Aspects of Solids & Light including the use of hands-on activities, interactive computer programs, inexpensive materials, and the focus on conceptual understanding were very applicable in the various physics classrooms observed. Both teachers and students gave these instructional strategies favorable ratings in motivating students to make observations and to learn. These ratings were not significantly affected by gender or students, attitudes towards physics or computers. Solid's & Light was applicable in terms of content and teaching style for some teachers. However, a mismatch of teaching styles between some instructors and the unit posed some problems in determining applicability. Observations indicated that some instructors were not able to utilize the exploratory instructional strategy of Solid's & Light. Thus, Solids & Light must include additional support necessary to make the instructor comfortable with the subject matter and pedagogical style. With these revisions, Solids & Light, will have all the key components to make its implementation in a high school physics classroom a successful one.

NASA Tech Briefs, September 1988. Volume 12, No. 8

NASA Technical Reports Server (NTRS)

1988-01-01

Topics include: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, October 1988. Volume 12, No. 9

NASA Technical Reports Server (NTRS)

1988-01-01

Topics include: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, July 1991. Volume 15, No. 7

NASA Technical Reports Server (NTRS)

1991-01-01

Topics include: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, March 1987. Volume 11, No. 3

NASA Technical Reports Server (NTRS)

1987-01-01

Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Fabrication Technology; Machinery; Mathematics and Information Sciences; Life Sciences.

An Illuminating Reaction.

ERIC Educational Resources Information Center

Matthews, Catherine E.

1996-01-01

Describes the use of carbide lights as an excellent mechanism for introducing or reviewing many basic chemistry concepts including elements and compounds, endothermic and exothermic reactions, physical and chemical changes, and balancing chemical equations. (JRH)

NASA Tech Briefs, May 1987. Volume 11, No. 5

NASA Technical Reports Server (NTRS)

1987-01-01

Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Fabrication Technology; Machinery; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, October 1987. Volume 11, No. 9

NASA Technical Reports Server (NTRS)

1987-01-01

Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Fabrication Technology; Machinery; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, June 1989. Volume 13, No. 6

NASA Technical Reports Server (NTRS)

1989-01-01

Topics include: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, February 1987. Volume 11, No. 2

NASA Technical Reports Server (NTRS)

1987-01-01

Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Fabrication Technology; Machinery; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, January 1987. Volume 11, No. 2

NASA Technical Reports Server (NTRS)

1987-01-01

Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Fabrication Technology; Machinery; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, July 1990. Volume 14, No. 7

NASA Technical Reports Server (NTRS)

1990-01-01

Topics include: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, April 1987. Volume 11, No. 4

NASA Technical Reports Server (NTRS)

1987-01-01

Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Fabrication Technology; Machinery; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, August 2002. Volume 26, No. 8

NASA Technical Reports Server (NTRS)

2002-01-01

Topics include: a technology focus on computers, electronic components and systems, software, materials, mechanics, machinery/automation, manufacturing, physical sciences, information sciences, book and reports, and Motion control Tech Briefs.

NASA Tech Briefs, September 1987. Volume 11, No. 8

NASA Technical Reports Server (NTRS)

1987-01-01

Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Fabrication Technology; Machinery; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, June 1994. Volume 18, No. 6

NASA Technical Reports Server (NTRS)

1994-01-01

Topics covered include: Microelectronics; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports

NASA Tech Briefs, August 1994. Volume 18, No. 8

NASA Technical Reports Server (NTRS)

1994-01-01

Topics covered include: Computer Hardware; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences; Books and Reports.

NASA Tech Briefs, October 1996. Volume 20, No. 10

NASA Technical Reports Server (NTRS)

1996-01-01

Topics covered include: Sensors; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports.

NASA Tech Briefs, June 1997. Volume 21, No. 6

NASA Technical Reports Server (NTRS)

1997-01-01

Topics include: Computer Hardware and Peripherals; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Books and Reports.

NASA Tech Briefs, June 1987. Volume 11, No. 6

NASA Technical Reports Server (NTRS)

1987-01-01

Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Fabrication Technology; Machinery; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, November 1999. Volume 23, No. 11

NASA Technical Reports Server (NTRS)

1999-01-01

Topics covered include: Computer-Aided Design and Engineering; Electronic Components and Circuits; Electronic Systems; Materials; Computer Programs; Mechanics; Machinery/Automation; Physical Sciences; Mathematics and Information Sciences; Books and Reports.

Physical Therapist Treatment of Patients in the Neurological Intensive Care Unit: Description of Practice

PubMed Central

Nordon-Craft, Amy; Malone, Daniel; Luby, Darcie M.; Schenkman, Margaret; Moss, Marc

2015-01-01

Background Although studies have established the safety and feasibility of physical therapy in the critical care setting, minimal information about physical therapist practice in the neurological intensive care unit (NICU) is available. Objective This study describes physical therapists' treatment of people admitted to a NICU. Design People admitted to the NICU with a diagnosis of subarachnoid hemorrhage, subdural hematoma, intracranial hemorrhage, or trauma were retrospectively studied. Methods Data on patient demographics, use of mechanical ventilation, and intracranial pressure (ICP) monitoring were collected. For each physical therapy session, the length of the session, the location (NICU or post-NICU setting), and the presence of mechanical ventilation or ICP monitoring were recorded. Data on safety parameters, including vital sign response, falls, and dislodgement of lines, were collected. Results Over 1 year, 180 people were admitted to the NICU; 86 were evaluated by a physical therapist, for a total of 293 physical therapy sessions in the NICU (n=132) or post-NICU setting (n=161). Only one session (0.3%) was stopped, secondary to an increase in ICP. The first physical therapy session occurred on NICU day 3.0 (25%–75% interquartile range=2.0–6.0). Patients received a median of 3.4 sessions per week (25%–75% interquartile range=1.8–5.9). Patients with mechanical ventilation received less frequent physical therapy sessions than those without mechanical ventilation. Patients with ICP monitoring received less frequent sessions than those without ICP monitoring. However, after multivariate analysis, only the admission Glasgow Coma Score was independently associated with physical therapy frequency in the NICU. Patients were more likely to stand, transfer, and walk in the post-NICU setting than in the NICU. Limitations The results are limited by the retrospective, single-center nature of the study. There is inherent bias of evaluating only those patients who had physical therapy, and therapists were unable to completely adjust for the severity of illness of a given patient. Conclusions Physical therapy was performed safely in the NICU. Patients who required invasive support received less frequent physical therapy. PMID:25655880

Mechanical Signaling for Bone Modeling and Remodeling

PubMed Central

Robling, Alexander G.; Turner, Charles H.

2012-01-01

Proper development of the skeleton in utero and during growth requires mechanical stimulation. Loading results in adaptive changes in bone that strengthen bone structure. Bone’s adaptive response is regulated by the ability of resident bone cells to perceive and translate mechanical energy into a cascade of structural and biochemical changes within the cells — a process known as mechanotransduction. Mechanotransduction pathways are among the most anabolic in bone, and consequently, there is great interest in elucidating how mechanical loading produces its observed effects, including increased bone formation, reduced bone loss, changes in bone cell differentiation and lifespan, among others. A molecular understanding of these processes is developing, and with it comes a profound new insight into the biology of bone. In this article, we review the nature of the physical stimulus to which bone cells mount an adaptive response, including the identity of the sensor cells, their attributes and physical environment, and putative mechanoreceptors they express. Particular attention is allotted to the focal adhesion and Wnt signaling, in light of their emerging role in bone mechanotransduction. The cellular mechanisms for increased bone loss during disuse, and reduced bone loss during loading are considered. Finally, we summarize the published data on bone cell accommodation, whereby bone cells stop responding to mechanical signaling events. Collectively, these data highlight the complex yet finely orchestrated process of mechanically regulated bone homeostasis. PMID:19817708

Meditative Movement, Energetic, and Physical Analyses of Three Qigong Exercises: Unification of Eastern and Western Mechanistic Exercise Theory.

PubMed

Klein, Penelope; Picard, George; Baumgarden, Joseph; Schneider, Roger

2017-09-23

Abstract : Qigong is the meditative movement and therapeutic exercise of Eastern medicine. A growing body of evidence is validating its health benefits leading to mechanistic questions of how it works. The purpose of this article is to explore mechanisms of action related to Qigong, with the intent of unifying Eastern and Western exercise theory and to present a model for Qigong exercise analysis. Three exercises from a standardized Qigong form: 'Plucking the Stars', 'Lotus Leaves Rustle in the Wind', and 'Pacing Forwards and Backwards' were selected for meditative, energetic, and physical analyses. Meditative aspects include relaxation response, interoception and exteroception. Energetic aspects include stimulation of meridians through mental intent, acupressure, and self-massage. Physical aspects include flexibility, strength, articular stimulation, neuro-integration, respiratory effect, fascial stretch, visceral massage, balance challenge CranioSacral pump, lymphatic and venous return and glandular stimulation, and physiologic response to relaxation. Knowledge of mechanisms of action for specific Qigong exercises can guide operational definition of Qigong, selection of outcomes assessment in future research, inform prescriptive practice addressing clinical health issues, and advance adoption of Qigong practice within integrative health care. The model of analysis demonstrated in this discussion may assist in these endeavors.

Effect of Sintering on Mechanical and Physical Properties of Plasma-Sprayed Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Choi, Sung R.; Zhu, Dong-Ming; Miller, Robert A.

2004-01-01

The effect of sintering on mechanical and physical properties of free-standing plasma-sprayed ZrO2-8 wt% Y2O3 thermal barrier coatings (TBCs) was determined by annealing them at 1316 C in air. Mechanical and physical properties of the TBCs, including strength, modes I and II fracture toughness, elastic modulus, Poisson s response, density, microhardness, fractography, and phase stability, were determined at ambient temperature as a function of annealing time ranging from 0 to 500 h. All mechanical and physical properties, except for the amount of monoclinic phase, increased significantly in 5 to 100 h and then reached a plateau above 100 h. Annealing resulted in healing of microcracks and pores and in grain growth, accompanying densification of the TBC s body due to the sintering effect. However, an inevitable adverse effect also occurred such that the desired lower thermal conductivity and good expansivity, which makes the TBCs unique in thermal barrier applications, were degraded upon annealing. A model was proposed to assess and quantify all the property variables in response to annealing in a normalized scheme. Directionality of as-sprayed TBCs appeared to have an insignificant effect on their properties, as determined via fracture toughness, microhardness, and elastic modulus measurements.

SOURCES OF INFORMATION ON ROCK PHYSICS. CURRENT LITERATURE, FEBRUARY 28, 1962

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burgin, L.

1962-02-28

A literature review on the field of rock physics, rock mechanics, wave propagation and other related subjects is presented. The 206 references, wtth abstracts, are included under the following categories: physical properties, rock deformation, loading, engineering applications, seismology, wave propagation, and instruments and methods. In each section the articles are arranged alphabetically according to author. The titles are from material which was made available at the Colorado School of Mines, Arthur Lakes Library during February 1962. (M.C.G.)

Nickel hydroxides and related materials: a review of their structures, synthesis and properties

PubMed Central

Hall, David S.; Lockwood, David J.; Bock, Christina; MacDougall, Barry R.

2015-01-01

This review article summarizes the last few decades of research on nickel hydroxide, an important material in physics and chemistry, that has many applications in engineering including, significantly, batteries. First, the structures of the two known polymorphs, denoted as α-Ni(OH)2 and β-Ni(OH)2, are described. The various types of disorder, which are frequently present in nickel hydroxide materials, are discussed including hydration, stacking fault disorder, mechanical stresses and the incorporation of ionic impurities. Several related materials are discussed, including intercalated α-derivatives and basic nickel salts. Next, a number of methods to prepare, or synthesize, nickel hydroxides are summarized, including chemical precipitation, electrochemical precipitation, sol–gel synthesis, chemical ageing, hydrothermal and solvothermal synthesis, electrochemical oxidation, microwave-assisted synthesis, and sonochemical methods. Finally, the known physical properties of the nickel hydroxides are reviewed, including their magnetic, vibrational, optical, electrical and mechanical properties. The last section in this paper is intended to serve as a summary of both the potentially useful properties of these materials and the methods for the identification and characterization of ‘unknown’ nickel hydroxide-based samples. PMID:25663812

NASA Tech Briefs, February 1997. Volume 2, No. 2

NASA Technical Reports Server (NTRS)

1997-01-01

Topics include: Test and Measurement; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports

NASA Tech Briefs, November 1988. Volume 12, No. 10

NASA Technical Reports Server (NTRS)

1988-01-01

Topics covered include: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, September/October 1986. Volume 10, No. 5

NASA Technical Reports Server (NTRS)

1986-01-01

Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Fabrication Technology; Machinery; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, April 1998. Volume 22, No. 4

NASA Technical Reports Server (NTRS)

1998-01-01

Topics include: special coverage on video and imaging, electronic components and circuits, electronic systems, physical sciences, materials, computer software, mechanics, machinery/automation, and a special section of Photonics Tech Briefs.

NASA Tech Briefs, May 1996. Volume 20, No. 5

NASA Technical Reports Server (NTRS)

1996-01-01

Topics include: Video and Imaging;Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports

NASA Tech Briefs, November/December 1986. Volume 10, No. 6

NASA Technical Reports Server (NTRS)

1986-01-01

Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Fabrication Technology; Machinery; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, October 1993. Volume 17, No. 10

NASA Technical Reports Server (NTRS)

1993-01-01

Topics include: Sensors; esign and Engineering; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication technology; Mathematics and Information Sciences; Life Sciences; Books and Reports.

NASA Tech Briefs, May 1994. Volume 18, No. 5

NASA Technical Reports Server (NTRS)

1994-01-01

Topics covered include: Robotics/Automation; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports.

NASA Tech Briefs, September 1990. Volume 14, No. 9

NASA Technical Reports Server (NTRS)

1990-01-01

Topics covered include: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, November/December 1987. Volume 11, No. 10

NASA Technical Reports Server (NTRS)

1987-01-01

Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Fabrication Technology; Machinery; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, February 1994. Volume 18, No. 2

NASA Technical Reports Server (NTRS)

1994-01-01

Topics covered include: Test and Measurement; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences; Books and Reports

NASA Tech Briefs, March 1988. Volume 12, No. 3

NASA Technical Reports Server (NTRS)

1988-01-01

Topics include: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; and Life Sciences.

NASA Tech Briefs, January 2000. Volume 24, No. 1

NASA Technical Reports Server (NTRS)

2000-01-01

Topics include: Data Acquisition; Computer-Aided Design and Engineering; Electronic Components and Circuits; Electronic Systems; Bio-Medical; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Information Sciences; Books and reports.

NASA Tech Briefs, July/August 1987. Volume 11, No. 7

NASA Technical Reports Server (NTRS)

1987-01-01

Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Fabrication Technology; Machinery; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, October 1995. Volume 19, No. 10

NASA Technical Reports Server (NTRS)

1995-01-01

A special focus in this issue is Data acquisition and analysis. Topics covered include : Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Life Sciences; Mechanics; Machinery; Fabrication Technology; and Mathematics and Information Sciences. Also included in this issue are Laser Tech Briefs and Industry Focus: Motion Control/ Positioning Equipment

Interplay of Physical Mechanisms and Biofilm Processes: Review of Microfluidic Methods

PubMed Central

Karimi, A.; Karig, D.; Kumar, A.; Ardekani, A. M.

2014-01-01

Bacteria in natural and artificial environments often reside in self-organized, integrated communities known as biofilms. Biofilms are highly structured entities consisting of bacterial cells embedded in a matrix of self-produced extracellular polymeric substances (EPS). The EPS matrix acts like a biological ‘glue’ enabling microbes to adhere to and colonize a wide range of surfaces. Once integrated into biofilms, bacterial cells can withstand various forms of stress such as antibiotics, hydrodynamic shear and other environmental challenges. Because of this, biofilms of pathogenic bacteria can be a significant health hazard often leading to recurrent infections. Biofilms can also lead to clogging and material degradation; on the other hand they are an integral part of various environmental processes such as carbon sequestration and nitrogen cycles. There are several determinants of biofilm morphology and dynamics, including the genotypic and phenotypic states of constituent cells and various environmental conditions. Here, we present an overview of the role of relevant physical processes in biofilm formation, including propulsion mechanisms, hydrodynamic effects, and transport of quorum sensing signals. We also provide a survey of microfluidic techniques utilized to unravel the associated physical mechanisms. Further, we discuss the future research areas for exploring new ways to extend the scope of the microfluidic approach in biofilm studies. PMID:25385289

Research Projects in Physics: A Mechanism for Teaching Ill-Structured Problem Solving

NASA Astrophysics Data System (ADS)

Milbourne, Jeff; Bennett, Jonathan

2017-10-01

Physics education research has a tradition of studying problem solving, exploring themes such as physical intuition and differences between expert and novice problem solvers. However, most of this work has focused on traditional, or well-structured, problems, similar to what might appear in a textbook. Less work has been done with open-ended, or ill-structured, problems, similar to the types of problems students might face in their professional lives. Given the national discourse on educational system reform aligned with 21st century skills, including problem solving, it is critical to provide educational experiences that help students learn to solve all types of problems, including ill-structured problems.

Primary blast-induced traumatic brain injury: lessons from lithotripsy

NASA Astrophysics Data System (ADS)

Nakagawa, A.; Ohtani, K.; Armonda, R.; Tomita, H.; Sakuma, A.; Mugikura, S.; Takayama, K.; Kushimoto, S.; Tominaga, T.

2017-11-01

Traumatic injury caused by explosive or blast events is traditionally divided into four mechanisms: primary, secondary, tertiary, and quaternary blast injury. The mechanisms of blast-induced traumatic brain injury (bTBI) are biomechanically distinct and can be modeled in both in vivo and in vitro systems. The primary bTBI injury mechanism is associated with the response of brain tissue to the initial blast wave. Among the four mechanisms of bTBI, there is a remarkable lack of information regarding the mechanism of primary bTBI. On the other hand, 30 years of research on the medical application of shock waves (SWs) has given us insight into the mechanisms of tissue and cellular damage in bTBI, including both air-mediated and underwater SW sources. From a basic physics perspective, the typical blast wave consists of a lead SW followed by shock-accelerated flow. The resultant tissue injury includes several features observed in primary bTBI, such as hemorrhage, edema, pseudo-aneurysm formation, vasoconstriction, and induction of apoptosis. These are well-described pathological findings within the SW literature. Acoustic impedance mismatch, penetration of tissue by shock/bubble interaction, geometry of the skull, shear stress, tensile stress, and subsequent cavitation formation are all important factors in determining the extent of SW-induced tissue and cellular injury. In addition, neuropsychiatric aspects of blast events need to be taken into account, as evidenced by reports of comorbidity and of some similar symptoms between physical injury resulting in bTBI and the psychiatric sequelae of post-traumatic stress. Research into blast injury biophysics is important to elucidate specific pathophysiologic mechanisms of blast injury, which enable accurate differential diagnosis, as well as development of effective treatments. Herein we describe the requirements for an adequate experimental setup when investigating blast-induced tissue and cellular injury; review SW physics, research, and the importance of engineering validation (visualization/pressure measurement/numerical simulation); and, based upon our findings of SW-induced injury, discuss the potential underlying mechanisms of primary bTBI.

Science Notes.

ERIC Educational Resources Information Center

School Science Review, 1985

1985-01-01

Presents 23 experiments, activities, field projects and computer programs in the biological and physical sciences. Instructional procedures, experimental designs, materials, and background information are suggested. Topics include fluid mechanics, electricity, crystals, arthropods, limpets, acid neutralization, and software evaluation. (ML)

NASA Tech Briefs, April 1997. Volume 21, No. 4

NASA Technical Reports Server (NTRS)

1997-01-01

Topics covered include: Video and Imaging; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports.

NASA Tech Briefs, March/April 1986. Volume 10, No. 2

NASA Technical Reports Server (NTRS)

1986-01-01

Topics covered include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

NASA Tech Briefs, February 1988. Volume 12, No. 2

NASA Technical Reports Server (NTRS)

1988-01-01

Topics covered include: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Systems; and Life Sciences.

NASA Tech Briefs, December 1993. Volume 17, No. 12

NASA Technical Reports Server (NTRS)

1993-01-01

Topics covered include: High-Performance Computing; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports.

NASA Tech Briefs, February 2000. Volume 24, No. 2

NASA Technical Reports Server (NTRS)

2000-01-01

Topics covered include: Test and Measurement; Computer-Aided Design and Engineering; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Bio-Medical; Mathematics and Information Sciences; Computers and Peripherals.

NASA Tech Briefs, April 2000. Volume 24, No. 4

NASA Technical Reports Server (NTRS)

2000-01-01

Topics covered include: Imaging/Video/Display Technology; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Bio-Medical; Test and Measurement; Mathematics and Information Sciences; Books and Reports.

NASA Tech Briefs, June 2002. Volume 26, No. 6

NASA Technical Reports Server (NTRS)

2002-01-01

Topics include: a technology focus on data acquisition, electronic components and systems, software, materials, mechanics, machinery/automation, physical sciences, book and reports, motion control, and a special section of Photonics Tech Briefs.

NASA Tech Briefs, January 1988. Volume 12, No. 1

NASA Technical Reports Server (NTRS)

1988-01-01

Topics covered include: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; and Life Sciences.

NASA Tech Briefs, March 1994. Volume 18, No. 3

NASA Technical Reports Server (NTRS)

1994-01-01

Topics include: Computer-Aided Design and Engineering; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports

NASA Tech Briefs, May 2002. Volume 26, No. 5

NASA Technical Reports Server (NTRS)

2002-01-01

Topics include: a technology focus on engineering materials, electronic components and circuits, software, mechanics, machinery/automation, manufacturing, physical sciences, information sciences, book and reports, and a special section of Photonics Tech Briefs.

NASA Tech Briefs, August 1996. Volume 20, No. 8

NASA Technical Reports Server (NTRS)

1996-01-01

Topics covered include: Graphics and Simulation; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports

NASA Tech Briefs, September 2002. Volume 26, No. 9

NASA Technical Reports Server (NTRS)

2002-01-01

Topics include: a technology focus on data acquisition, electronic components and systems, software, materials, mechanics, machinery/automation, bio-medical, physical sciences, book and reports, and a special section of Photonics Tech Briefs.

NASA Tech Briefs, March 2000. Volume 24, No. 3

NASA Technical Reports Server (NTRS)

2000-01-01

Topics include: Computer-Aided Design and Engineering; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports.

Nuclear spectroscopic studies. Progress report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bingham, C.R.; Guidry, M.W.; Riedinger, L.L.

1994-02-18

The Nuclear Physics group at UTK is involved in heavy-ion physics including both nuclear structure and reaction mechanisms. During the last year experimental work has been in 3 broad areas: structure of nuclei at high angular momentum, structure of nuclei far from stability, and ultra-relativistic heavy-ion physics. Results in these areas are described in this document under: properties of high-spin states, study of low-energy levels of nuclei far from stability, and high-energy heavy-ion physics (PHENIX, etc.). Another important component of the work is theoretical interpretation of experimental results (Joint Institute for Heavy Ion Research).

Solar radio emission

NASA Technical Reports Server (NTRS)

Goldman, M. V.; Smith, D. F.

1981-01-01

Active areas of both observational and theoretical research in which rapid progress is being made are discussed. These include: (1) the dynamic spectrum or frequency versus time plot; (2) physical mechanisms in the development of various types of bursts; (3) microwave type 1, 2, 3, and moving type 4 bursts; (4) bursts caused by trapped electrons; (5) physics of type 3bursts; (6) the physics of type 2 bursts and their related shocks; (7) the physics of both stationary and moving traps and associated type 1 and moving type 4 bursts; and (8) the status of the field of solar radio emission.

Physical biology of human brain development.

PubMed

Budday, Silvia; Steinmann, Paul; Kuhl, Ellen

2015-01-01

Neurodevelopment is a complex, dynamic process that involves a precisely orchestrated sequence of genetic, environmental, biochemical, and physical events. Developmental biology and genetics have shaped our understanding of the molecular and cellular mechanisms during neurodevelopment. Recent studies suggest that physical forces play a central role in translating these cellular mechanisms into the complex surface morphology of the human brain. However, the precise impact of neuronal differentiation, migration, and connection on the physical forces during cortical folding remains unknown. Here we review the cellular mechanisms of neurodevelopment with a view toward surface morphogenesis, pattern selection, and evolution of shape. We revisit cortical folding as the instability problem of constrained differential growth in a multi-layered system. To identify the contributing factors of differential growth, we map out the timeline of neurodevelopment in humans and highlight the cellular events associated with extreme radial and tangential expansion. We demonstrate how computational modeling of differential growth can bridge the scales-from phenomena on the cellular level toward form and function on the organ level-to make quantitative, personalized predictions. Physics-based models can quantify cortical stresses, identify critical folding conditions, rationalize pattern selection, and predict gyral wavelengths and gyrification indices. We illustrate that physical forces can explain cortical malformations as emergent properties of developmental disorders. Combining biology and physics holds promise to advance our understanding of human brain development and enable early diagnostics of cortical malformations with the ultimate goal to improve treatment of neurodevelopmental disorders including epilepsy, autism spectrum disorders, and schizophrenia.

Multiple effects of physical activity on molecular and cognitive signs of brain aging: can exercise slow neurodegeneration and delay Alzheimer's disease?

PubMed

Brown, B M; Peiffer, J J; Martins, R N

2013-08-01

Western countries are experiencing aging populations and increased longevity; thus, the incidence of dementia and Alzheimer's disease (AD) in these countries is projected to soar. In the absence of a therapeutic drug, non-pharmacological preventative approaches are being investigated. One of these approaches is regular participation in physical activity or exercise. This paper reviews studies that have explored the relationship between physical activity and cognitive function, cognitive decline, AD/dementia risk and AD-associated biomarkers and processes. There is now strong evidence that links regular physical activity or exercise to higher cognitive function, decreased cognitive decline and reduced risk of AD or dementia. Nevertheless, these associations require further investigation, more specifically with interventional studies that include long follow-up periods. In particular, relatively little is known about the underlying mechanism(s) of the associations between physical activity and AD neuropathology; clearly this is an area in need of further research, particularly in human populations. Although benefits of physical activity or exercise are clearly recognised, there is a need to clarify how much physical activity provides the greatest benefit and also whether people of different genotypes require tailored exercise regimes.

Key issues and technical route of cyber physical distribution system

NASA Astrophysics Data System (ADS)

Zheng, P. X.; Chen, B.; Zheng, L. J.; Zhang, G. L.; Fan, Y. L.; Pei, T.

2017-01-01

Relying on the National High Technology Research and Development Program, this paper introduced the key issues in Cyber Physical Distribution System (CPDS), mainly includes: composite modelling method and interaction mechanism, system planning method, security defence technology, distributed control theory. Then on this basis, the corresponding technical route is proposed, and a more detailed research framework along with main schemes to be adopted is also presented.

Gesellschaft fuer angewandte Mathematik und Mechanik, Scientific Annual Meeting, Universitaet Stuttgart, Federal Republic of Germany, Apr. 13-17, 1987, Reports

NASA Astrophysics Data System (ADS)

Recent advances in the analytical and numerical treatment of physical and engineering problems are discussed in reviews and reports. Topics addressed include fluid mechanics, numerical methods for differential equations, FEM approaches, and boundary-element methods. Consideration is given to optimization, decision theory, stochastics, actuarial mathematics, applied mathematics and mathematical physics, and numerical analysis.

Brillouin microspectroscopy of nanostructured biomaterials: photonics assisted tailoring mechanical properties

NASA Astrophysics Data System (ADS)

Meng, Zhaokai; Jaiswal, Manish K.; Chitrakar, Chandani; Thakur, Teena; Gaharwar, Akhilesh K.; Yakovlev, Vladislav V.

2016-03-01

Developing new biomaterials is essential for the next-generation of materials for bioenergy, bioelectronics, basic biology, medical diagnostics, cancer research, and regenerative medicine. Specifically, recent progress in nanotechnology has stimulated the development of multifunctional biomaterials for tissue engineering applications. The physical properties of nanocomposite biomaterials, including elasticity and viscosity, play key roles in controlling cell fate, which underlines therapeutic success. Conventional mechanical tests, including uniaxial compression and tension, dynamic mechanical analysis and shear rheology, require mechanical forces to be directly exerted onto the sample and therefore may not be suitable for in situ measurements or continuous monitoring of mechanical stiffness. In this study, we employ spontaneous Brillouin spectroscopy as a viscoelasticity-specific probing technique. We utilized a Brillouin spectrometer to characterize biomaterial's microscopic elasticity and correlated those with conventional mechanical tests (e.g., rheology).

Identifying potential working mechanisms behind the positive effects of exercise therapy on pain and function in osteoarthritis; a systematic review.

PubMed

Runhaar, J; Luijsterburg, P; Dekker, J; Bierma-Zeinstra, S M A

2015-07-01

Although physical exercise is the commonly recommended for osteoarthritis (OA) patients, the working mechanism behind the positive effects of physical exercise on pain and function is a black box phenomenon. In the present study we aimed to identify possible mediators in the relation between physical exercise and improvements of pain and function in OA patients. A systematic search for all studies evaluating the effects of physical exercise in OA patients and select those that additionally reported the change in any physiological factor from pre-to post-exercise. In total, 94 studies evaluating 112 intervention groups were included. Most included studies evaluated subjects with solely knee OA (96 out of 112 groups). Based on the measured physiological factors within the included studies, 12 categories of possible mediators were formed. Muscle strength and ROM/flexibility were the most measured categories of possible mediators with 61 and 21 intervention groups measuring one or more physiological factors within these categories, respectively. 60% (31 out of 52) of the studies showed a significant increase in knee extensor muscle strength and 71% (22 out of 31) in knee flexor muscle strength over the intervention period. All 5 studies evaluating extension impairments and 10 out of 12 studies (83%) measuring proprioception found a significant change from pre-to post-intervention. An increase of upper leg strength, a decrease of extension impairments and improvement in proprioception were identified as possible mediators in the positive association between physical exercise and OA symptoms. Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Physical and Mechanical Properties of W-Ni-Fe-Co Metal Foam Modified by Titanium Tungsten Carbide Alloying

NASA Astrophysics Data System (ADS)

Ishchenko, A. N.; Tabachenko, A. N.; Afanas'eva, S. A.; Belov, N. N.; Biryukov, Yu. A.; Burkin, V. V.; D'yachkovskii, A. S.; Rogaev, K. S.; Skosyrskii, A. B.; Yugov, N. T.

2018-02-01

The paper studies physical and mechanical properties of tungsten-nickel-iron-cobalt metal foam alloyed with titanium tungsten carbide. Test specimens are obtained by the liquid phase sintering of powder materials, including those containing tungsten nanopowders. High porosity metal foams are prepared through varying the porosity of powder specimens and the content of filling material. The penetration capability of cylinder projectiles made of new alloys is explored in this paper. It is shown that their penetration depth exceeds that of the prototype with relevant weight and size, made of tungsten-nickel-iron alloy, other factors being equal.

Classical Electrodynamics: Problems with solutions; Problems with solutions

NASA Astrophysics Data System (ADS)

Likharev, Konstantin K.

2018-06-01

l Advanced Physics is a series comprising four parts: Classical Mechanics, Classical Electrodynamics, Quantum Mechanics and Statistical Mechanics. Each part consists of two volumes, Lecture notes and Problems with solutions, further supplemented by an additional collection of test problems and solutions available to qualifying university instructors. This volume, Classical Electrodynamics: Lecture notes is intended to be the basis for a two-semester graduate-level course on electricity and magnetism, including not only the interaction and dynamics charged point particles, but also properties of dielectric, conducting, and magnetic media. The course also covers special relativity, including its kinematics and particle-dynamics aspects, and electromagnetic radiation by relativistic particles.

Regulation of Cell Cytoskeleton and Membrane Mechanics by Electric Field: Role of Linker Proteins

PubMed Central

Titushkin, Igor; Cho, Michael

2009-01-01

Abstract Cellular mechanics is known to play an important role in the cell homeostasis including proliferation, motility, and differentiation. Significant variation in the mechanical properties between different cell types suggests that control of the cell metabolism is feasible through manipulation of the cell mechanical parameters using external physical stimuli. We investigated the electrocoupling mechanisms of cellular biomechanics modulation by an electrical stimulation in two mechanically distinct cell types—human mesenchymal stem cells and osteoblasts. Application of a 2 V/cm direct current electric field resulted in approximately a twofold decrease in the cell elasticity and depleted intracellular ATP. Reduction in the ATP level led to inhibition of the linker proteins that are known to physically couple the cell membrane and cytoskeleton. The membrane separation from the cytoskeleton was confirmed by up to a twofold increase in the membrane tether length that was extracted from the cell membrane after an electrical stimulation. In comparison to human mesenchymal stem cells, the membrane-cytoskeleton attachment in osteoblasts was much stronger but, in response to the same electrical stimulation, the membrane detachment from the cytoskeleton was found to be more pronounced. The observed effects mediated by an electric field are cell type- and serum-dependent and can potentially be used for electrically assisted cell manipulation. An in-depth understanding and control of the mechanisms to regulate cell mechanics by external physical stimulus (e.g., electric field) may have great implications for stem cell-based tissue engineering and regenerative medicine. PMID:19167316

High-performance coupled poro-hydro-mechanical models to resolve fluid escape pipes

NASA Astrophysics Data System (ADS)

Räss, Ludovic; Makhnenko, Roman; Podladchikov, Yury

2017-04-01

Field observations and laboratory experiments exhibit inelastic deformation features arising in many coupled settings relevant to geo-applications. These irreversible deformations and their specific patterns suggest a rather ductile or brittle mechanism, such as viscous creep or micro cracks, taking place on both geological (long) and human (short) timescales. In order to understand the underlying mechanisms responsible for these deformation features, there is a current need to accurately resolve the non-linearities inherent to strongly coupled physical processes. Among the large variety of modelling tools and softwares available nowadays in the community, very few are capable to efficiently solve coupled systems with high accuracy in both space and time and run efficiently on modern hardware. Here, we propose a robust framework to solve coupled multi-physics hydro-mechanical processes on very high spatial and temporal resolution in both two and three dimensions. Our software relies on the Finite-Difference Method and a pseudo-transient scheme is used to converge to the implicit solution of the system of poro-visco-elasto-plastic equations at each physical time step. The rheology including viscosity estimates for major reservoir rock types is inferred from novel lab experiments and confirms the ease of flow of sedimentary rocks. Our results propose a physical mechanism responsible for the generation of high permeability pathways in fluid saturated porous media and predict their propagation in rates observable on operational timescales. Finally, our software scales linearly on more than 5000 GPUs.

Modeling Instruction in AP Physics C: Mechanics and Electricity and Magnetism

NASA Astrophysics Data System (ADS)

Belcher, Nathan Tillman

This action research study used data from multiple assessments in Mechanics and Electricity and Magnetism to determine the viability of Modeling Instruction as a pedagogy for students in AP Physics C: Mechanics and Electricity and Magnetism. Modeling Instruction is a guided-inquiry approach to teaching science in which students progress through the Modeling Cycle to develop a fully-constructed model for a scientific concept. AP Physics C: Mechanics and Electricity and Magnetism are calculus-based physics courses, approximately equivalent to first-year calculus-based physics courses at the collegiate level. Using a one-group pretest-posttest design, students were assessed in Mechanics using the Force Concept Inventory, Mechanics Baseline Test, and 2015 AP Physics C: Mechanics Practice Exam. With the same design, students were assessed in Electricity and Magnetism on the Brief Electricity and Magnetism Assessment, Electricity and Magnetism Conceptual Assessment, and 2015 AP Physics C: Electricity and Magnetism Practice Exam. In a one-shot case study design, student scores were collected from the 2017 AP Physics C: Mechanics and Electricity and Magnetism Exams. Students performed moderately well on the assessments in Mechanics and Electricity and Magnetism, demonstrating that Modeling Instruction is a viable pedagogy in AP Physics C: Electricity and Magnetism.

Mechanical behaviour׳s evolution of a PLA-b-PEG-b-PLA triblock copolymer during hydrolytic degradation.

PubMed

Breche, Q; Chagnon, G; Machado, G; Girard, E; Nottelet, B; Garric, X; Favier, D

2016-07-01

PLA-b-PEG-b-PLA is a biodegradable triblock copolymer that presents both the mechanical properties of PLA and the hydrophilicity of PEG. In this paper, physical and mechanical properties of PLA-b-PEG-b-PLA are studied during in vitro degradation. The degradation process leads to a mass loss, a decrease of number average molecular weight and an increase of dispersity index. Mechanical experiments are made in a specific experimental set-up designed to create an environment close to in vivo conditions. The viscoelastic behaviour of the material is studied during the degradation. Finally, the mechanical behaviour is modelled with a linear viscoelastic model. A degradation variable is defined and included in the model to describe the hydrolytic degradation. This variable is linked to physical parameters of the macromolecular polymer network. The model allows us to describe weak deformations but become less accurate for larger deformations. The abilities and limits of the model are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Cellular mechanisms of neuroplasticity].

PubMed

Bergado-Rosado, J A; Almaguer-Melian, W

To present a unified vision of the principal known mechanisms of neuroplasticity, emphasizing their universality. The concept of the central nervous system as an immutable entity has been considerably modified during the second half of the 20th century. Neuroplasticity, that is the ability of the brain regarding change and repair is expressed in different ways, from functional modifications of existing structures to the formation, by growth and proliferation, of new structures and neurons. This study considers the molecular and cellular mechanisms of neuroplastic phenomena and classifies them into two main groups: plasticity due to growth, including the mechanisms of axonal regeneration, collateralization and reactive synaptogenesis; and functional plasticity, which includes changes in the efficacy of synaptic transmission such as long-term potentiation and the activation of silent synapses. We also describe some of the relations of neuroplastic phenomena with disease of the central nervous system, together with examples of physiological, physical and pharmacological factors which may be used in future as therapeutic tools to stimulate and modulate neuroplasticity. Neuroplastic mechanisms show a high degree of phylogenetic and ontogenetic conservation. They are important both in the genesis of disorders and disease of the nervous system and for its repair after different types of damage and trauma. Modulation of neuroplastic mechanisms by physical and chemical agents would appear to be one of the most powerful therapeutic tools of restorative neurology.

NASA Tech Briefs, July 1994. Volume 18, No. 7

NASA Technical Reports Server (NTRS)

1994-01-01

Topics covered include: Computer-Aided Design and Engineering; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports

Science Notes.

ERIC Educational Resources Information Center

School Science Review, 1985

1985-01-01

Presents biology, chemistry, physics, and health activities, experiments, demonstrations, and computer programs. Includes mechanism of stomatal opening, using aquatic plants to help demonstrate chemical buffering, microbial activity/contamination in milk samples, computer computation of fitness scores, reservoir project, complexes of transition…

NASA Tech Briefs, July/August 1986. Volume 10, No. 4

NASA Technical Reports Server (NTRS)

1986-01-01

Topic include: NASA TU Serv1ces; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Materials; Computer Programs; Mechanics; Physical Sciences; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences. 3

NASA Tech Briefs, November 2002. Volume 26, No. 11

NASA Technical Reports Server (NTRS)

2002-01-01

Topics include: a technology focus on engineering materials, electronic components and systems, software, mechanics, machinery/automation, manufacturing, bio-medical, physical sciences, information sciences book and reports, and a special section of Photonics Tech Briefs.

NASA Tech Briefs, August 2001. Volume 25, No. 8

NASA Technical Reports Server (NTRS)

2001-01-01

Topics include: special coverage section on computers and peripherals, and sections on electronic components systems, software, materials, mechanics, manufacturing/fabrication, physical sciences, book and reports, and a special section of Motion Control Tech Briefs.

NASA Tech Briefs, October 2002. Volume 26, No. 10

NASA Technical Reports Server (NTRS)

2002-01-01

Topics include: a technology focus on sensors, electronic components and systems, software, materials, materials, mechanics, manufacturing, physical sciences, information sciences, book and reports, motion control and a special section of Photonics Tech Briefs.

NASA Tech Briefs, March 2002. Volume 26, No. 3

NASA Technical Reports Server (NTRS)

2002-01-01

Topics include: a special section on data acquisition, software, electronic components and systems, materials, computer programs, mechanics, machinery/automation, manufacturing, biomedical, physical sciences, book and reports, and a special section of Photonics Tech Briefs.

NASA Tech Briefs, July 2002. Volume 26, No. 7

NASA Technical Reports Server (NTRS)

2002-01-01

Topics include: a technology focus sensors, software, electronic components and systems, materials, mechanics, machinery/automation, manufacturing, bio-medical, physical sciences, information sciences, book and reports, and a special section of Photonics Tech Briefs.

NASA Tech Briefs, May 1997. Volume 21, No. 5

NASA Technical Reports Server (NTRS)

1997-01-01

Topics covered include: Advanced Composites, Plastics and Metals; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports.

ENVIRONMENTALLY FRIENDLY LEATHER TANNING USING ENZYMES

EPA Science Inventory

The effectiveness of the leather tanning will be evaluated by measuring shrinkage temperature, and analyzing leather structure using Scan Electron Microscope (SEM). The team will also measure leather physical/mechanical properties, including softness, tensile strength, elon...

NASA Tech Briefs, January 1996. Volume 20, No. 1

NASA Technical Reports Server (NTRS)

1996-01-01

This issue has a special focus on sensors, and include articles on Electronic Components and Circuits, Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery/Automation, Manufacturing/Fabrication, and Mathematics and Information Sciences

NASA Tech Briefs, November 2000. Volume 24, No. 11

NASA Technical Reports Server (NTRS)

2000-01-01

Topics covered include: Computer-Aided Design and Engineering; Electronic Components and Circuits; Electronic Systems; Test and Measurement; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Data Acquisition.

NASA Tech Briefs, April 1996. Volume 20, No. 4

NASA Technical Reports Server (NTRS)

1996-01-01

Topics covered include: Advanced Composites and Plastics; Computer-Aided Design and Engineering; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information; Books and Reports.

Quantum mechanical derivation of the Wallis formula for π

DOE Office of Scientific and Technical Information (OSTI.GOV)

Friedmann, Tamar, E-mail: tfriedma@ur.rochester.edu; Hagen, C. R., E-mail: hagen@pas.rochester.edu

2015-11-15

A famous pre-Newtonian formula for π is obtained directly from the variational approach to the spectrum of the hydrogen atom in spaces of arbitrary dimensions greater than one, including the physical three dimensions.

A novel mechanical model for phase-separation in debris flows

NASA Astrophysics Data System (ADS)

Pudasaini, Shiva P.

2015-04-01

Understanding the physics of phase-separation between solid and fluid phases as a two-phase mass moves down slope is a long-standing challenge. Here, I propose a fundamentally new mechanism, called 'separation-flux', that leads to strong phase-separation in avalanche and debris flows. This new model extends the general two-phase debris flow model (Pudasaini, 2012) to include a separation-flux mechanism. The new flux separation mechanism is capable of describing and controlling the dynamically evolving phase-separation, segregation, and/or levee formation in a real two-phase, geometrically three-dimensional debris flow motion and deposition. These are often observed phenomena in natural debris flows and industrial processes that involve the transportation of particulate solid-fluid mixture material. The novel separation-flux model includes several dominant physical and mechanical aspects that result in strong phase-separation (segregation). These include pressure gradients, volume fractions of solid and fluid phases and their gradients, shear-rates, flow depth, material friction, viscosity, material densities, boundary structures, gravity and topographic constraints, grain shape, size, etc. Due to the inherent separation mechanism, as the mass moves down slope, more and more solid particles are brought to the front, resulting in a solid-rich and mechanically strong frontal surge head followed by a weak tail largely consisting of the viscous fluid. The primary frontal surge head followed by secondary surge is the consequence of the phase-separation. Such typical and dominant phase-separation phenomena are revealed here for the first time in real two-phase debris flow modeling and simulations. However, these phenomena may depend on the bulk material composition and the applied forces. Reference: Pudasaini, Shiva P. (2012): A general two-phase debris flow model. J. Geophys. Res., 117, F03010, doi: 10.1029/2011JF002186.

Physical activity and cancer risk: dose-response and cancer, all sites and site-specific.

PubMed

Thune, I; Furberg, A S

2001-06-01

The association between physical activity and overall and site-specific cancer risk is elaborated in relation to whether any observed dose-response association between physical activity and cancer can be interpreted in terms of how much physical activity (type, intensity, duration, frequency) is needed to influence site- and gender-specific cancer risk. Observational studies were reviewed that have examined the independent effect of the volume of occupational physical activity (OPA) and/or leisure time physical activity (LPA) on overall and site-specific cancer risk. The evidence of cohort and case-control studies suggests that both leisure time and occupational physical activity protect against overall cancer risk, with a graded dose-response association suggested in both sexes. Confounding effects such as diet, body weight, and parity are often included as a covariate in the analyses, with little influence on the observed associations. A crude graded inverse dose-response association was observed between physical activity and colon cancer in 48 studies including 40,674 colon/colorectal cancer cases for both sexes. A dose-response effect of physical activity on colon cancer risk was especially observed, when participation in activities of at least moderate activity (>4.5 MET) and demonstrated by activities expressed as MET-hours per week. An observed inverse association with a dose-response relationship between physical activity and breast cancer was also identified in the majority of the 41 studies including 108,031 breast cancer cases. The dose-response relationship was in particular observed in case-control studies and supported by observations in cohort studies when participation in activities of at least moderate activity (>4.5 MET) and demonstrated by activities expressed by MET-hours per week. This association between physical activity and breast cancer risk is possibly dependent on age at exposure, age at diagnosis, menopausal status and other effect modifiers, e.g., body mass index. Furthermore, data concerning carcinoma of other cancers (prostate, lung, endometrium, ovary, and testicular cancers) are required. A protective effect of physical activity on site-specific cancer risk with a dose-response association between physical activity and colon and pre- and postmenopausal breast cancer supported by identified biological mechanisms has been observed. The optimal permutation of type, intensity, duration, and frequency of physical activity across the lifespan is unclear, but it is gender, age, and site specific and supports moderate activity (>4.5 MET) more than light activities (<4.5 MET). The complicated nature of the physical activity variable, combined with lack of knowledge regarding possible biological mechanisms operating between physical activity and cancer, warrants further studies including controlled clinical randomized trials.

Mechanisms of tubular sodium chloride transport.

PubMed

Venkatesh, S; Schrier, R W; Andreoli, T E

1998-11-01

Extracellular fluid volume is determined by sodium and its accompanying anions. There are control mechanisms which regulate sodium balance in the body. These include high and low pressure baroreceptors, intrarenal baroreceptors, renal autoregulation, tubuloglomerular feedback, aldosterone, and numerous other physical and hormonal factors. Sodium transport by the nephron involves active and passive processes which occur in several different nephron segments. Mechanisms of cotransport, Na(+)-H+ exchange, antiporters and ion-specific channels are all utilized by the nephron to maintain sodium balance. These regulatory factors and transport mechanisms for sodium in the kidney will he discussed in detail.

Neighborhood and Family Environment of Expectans Mothers May Influence Prenatal Programming of Adult Cancer Risk: Discussion and an Illustrative DNA Methylation Example

EPA Science Inventory

Childhood stressors including physical abuse predict adult cancer risk. Prior research portrays this finding as an indirect mechanism that operates through coping behaviors, including adult smoking, or through increased toxic exposures during childhood. Little is known about pote...

Photoassisted physical vapor epitaxial growth of semiconductors: a review of light-induced modifications to growth processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alberi, Kirstin; Scarpulla, Michael A.

Herein, we review the remarkable range of modifications to materials properties associated with photoexcitation of the growth surface during physical vapor epitaxy of semiconductors. We concentrate on mechanisms producing measureable, utilizable changes in crystalline perfection, phase, composition, doping, and defect distribution. We outline the relevant physics of different mechanisms, concentrating on those yielding effects orthogonal to the primary growth variables of temperature and atomic or molecular fluxes and document the phenomenological effects reported. Based on experimental observations from a range of semiconductor systems and growth conditions, the primary effects include enhanced anion desorption, molecular dissociation, increased doping efficiency, modification tomore » defect populations and improvements to the crystalline quality of epilayers grown at low temperatures. Future research directions and technological applications are also discussed.« less

'Known Secure Sensor Measurements' for Critical Infrastructure Systems: Detecting Falsification of System State

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miles McQueen; Annarita Giani

2011-09-01

This paper describes a first investigation on a low cost and low false alarm, reliable mechanism for detecting manipulation of critical physical processes and falsification of system state. We call this novel mechanism Known Secure Sensor Measurements (KSSM). The method moves beyond analysis of network traffic and host based state information, in fact it uses physical measurements of the process being controlled to detect falsification of state. KSSM is intended to be incorporated into the design of new, resilient, cost effective critical infrastructure control systems. It can also be included in incremental upgrades of already in- stalled systems for enhancedmore » resilience. KSSM is based on known secure physical measurements for assessing the likelihood of an attack and will demonstrate a practical approach to creating, transmitting, and using the known secure measurements for detection.« less

Photoassisted physical vapor epitaxial growth of semiconductors: a review of light-induced modifications to growth processes

DOE PAGES

Alberi, Kirstin; Scarpulla, Michael A.

2017-11-22

Herein, we review the remarkable range of modifications to materials properties associated with photoexcitation of the growth surface during physical vapor epitaxy of semiconductors. We concentrate on mechanisms producing measureable, utilizable changes in crystalline perfection, phase, composition, doping, and defect distribution. We outline the relevant physics of different mechanisms, concentrating on those yielding effects orthogonal to the primary growth variables of temperature and atomic or molecular fluxes and document the phenomenological effects reported. Based on experimental observations from a range of semiconductor systems and growth conditions, the primary effects include enhanced anion desorption, molecular dissociation, increased doping efficiency, modification tomore » defect populations and improvements to the crystalline quality of epilayers grown at low temperatures. Future research directions and technological applications are also discussed.« less

Exercising the hepatobiliary-gut axis. The impact of physical activity performance.

PubMed

Molina-Molina, Emilio; Lunardi Baccetto, Raquel; Wang, David Q-H; de Bari, Ornella; Krawczyk, Marcin; Portincasa, Piero

2018-05-24

Physical inactivity puts the populations at risk of several health problems, while regular physical activity brings beneficial effects on cardiovascular disease, mortality and other health outcomes, including obesity, glycaemic control and insulin resistance. The hepatobiliary tract is greatly involved in several metabolic aspects which include digestion and absorption of nutrients in concert with intestinal motility, bile acid secretion and flow across the enterohepatic circulation and intestinal microbiota. Several metabolic abnormalities, including nonalcoholic fatty liver as well as cholesterol cholelithiasis, represent two conditions explained by changes of the aforementioned pathways. This review defines different training modalities and discusses the effects of physical activity in two metabolic disorders, that is nonalcoholic fatty liver disease (NAFLD) and cholelithiasis. Emphasis is given to pathogenic mechanisms involving intestinal bile acids, microbiota and inflammatory status. A full definition of physical activity includes the knowledge of aerobic and endurance exercise, metabolic equivalent tasks, duration, frequency and intensity, beneficial and harmful effects. Physical activity influences the hepatobiliary-gut axis at different levels and brings benefits to fat distribution, liver fat and gallbladder disease while interacting with bile acids as signalling molecules, intestinal microbiota and inflammatory changes in the body. Several beneficial effects of physical activity are anticipated on metabolic disorders linking liver steatosis, gallstone disease, gut motility, enterohepatic circulation of signalling bile acids in relation to intestinal microbiota and inflammatory changes. © 2018 Stichting European Society for Clinical Investigation Journal Foundation.

Physics of Health Sciences

NASA Astrophysics Data System (ADS)

Baublitz, Millard; Goldberg, Bennett

A one-semester algebra-based physics course is being offered to Boston University students whose major fields of study are in allied health sciences: physical therapy, athletic training, and speech, language, and hearing sciences. The classroom instruction incorporates high-engagement learning techniques including worksheets, student response devices, small group discussions, and physics demonstrations instead of traditional lectures. The use of pre-session exercises and quizzes has been implemented. The course also requires weekly laboratory experiments in mechanics or electricity. We are using standard pre- and post-course concept inventories to compare this one-semester introductory physics course to ten years of pre- and post-course data collected on students in the same majors but who completed a two-semester course.

Behaviour change techniques in physical activity interventions for men with prostate cancer: A systematic review.

PubMed

Hallward, Laura; Patel, Nisha; Duncan, Lindsay R

2018-02-01

Physical activity interventions can improve prostate cancer survivors' health. Determining the behaviour change techniques used in physical activity interventions can help elucidate the mechanisms by which an intervention successfully changes behaviour. The purpose of this systematic review was to identify and evaluate behaviour change techniques in physical activity interventions for prostate cancer survivors. A total of 7 databases were searched and 15 studies were retained. The studies included a mean 6.87 behaviour change techniques (range = 3-10), and similar behaviour change techniques were implemented in all studies. Consideration of how behaviour change techniques are implemented may help identify how behaviour change techniques enhance physical activity interventions for prostate cancer survivors.

From quantum foundations to applications and back.

PubMed

Gisin, Nicolas; Fröwis, Florian

2018-07-13

Quantum non-locality has been an extremely fruitful subject of research, leading the scientific revolution towards quantum information science, in particular, to device-independent quantum information processing. We argue that the time is ripe to work on another basic problem in the foundations of quantum physics, the quantum measurement problem, which should produce good physics in theoretical, mathematical, experimental and applied physics. We briefly review how quantum non-locality contributed to physics (including some outstanding open problems) and suggest ways in which questions around macroscopic quantumness could equally contribute to all aspects of physics.This article is part of a discussion meeting issue 'Foundations of quantum mechanics and their impact on contemporary society'. © 2018 The Author(s).

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

NASA Astrophysics Data System (ADS)

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 particular the understanding of mechano-coupling and mechano-regulating functions in cell invasion, appears as an important step in cancer progression and inflammatory response to injuries. This may lead to novel insights into cancer disease and inflammatory diseases and will overcome classical views on cancer and inflammation. In addition, this review will discuss how the physics of cancer and inflammation can help to reveal whether cancer cells will invade connective tissue and metastasize or how leukocytes extravasate and migrate through the tissue. In this review, the physical concepts of cancer progression, including the tissue basement membrane a cancer cell is crossing, its invasion and transendothelial migration as well as the basic physical concepts of inflammatory processes and the cellular responses to the mechanical stress of the microenvironment such as external forces and matrix stiffness, are presented and discussed. In conclusion, this review will finally show how physical measurements can improve classical approaches that investigate cancer and inflammatory diseases, and how these physical insights can be integrated into classical tumor biological approaches.

Workshop Physics Activity Guide, Module 2: Mechanics II, Momentum, Energy, Rotational and Harmonic Motion, and Chaos (Units 8 - 15)

NASA Astrophysics Data System (ADS)

Laws, Priscilla W.

2004-05-01

The Workshop Physics Activity Guide is a set of student workbooks designed to serve as the foundation for a two-semester calculus-based introductory physics course. It consists of 28 units that interweave text materials with activities that include prediction, qualitative observation, explanation, equation derivation, mathematical modeling, quantitative experiments, and problem solving. Students use a powerful set of computer tools to record, display, and analyze data, as well as to develop mathematical models of physical phenomena. The design of many of the activities is based on the outcomes of physics education research. The Workshop Physics Activity Guide is supported by an Instructor's Website that: (1) describes the history and philosophy of the Workshop Physics Project; (2) provides advice on how to integrate the Guide into a variety of educational settings; (3) provides information on computer tools (hardware and software) and apparatus; and (4) includes suggested homework assignments for each unit. Log on to the Workshop Physics Project website at http://physics.dickinson.edu/ Workshop Physics is a component of the Physics Suite--a collection of materials created by a group of educational reformers known as the Activity Based Physics Group. The Physics Suite contains a broad array of curricular materials that are based on physics education research, including:

Understanding Physics, by Cummings, Laws, Redish and Cooney (an introductory textbook based on the best-selling text by Halliday/Resnick/Walker) RealTime Physics Laboratory Modules Physics by Inquiry (intended for use in a workshop setting) Interactive Lecture Demonstration Tutorials in Introductory Physics Activity Based Tutorials (designed primarily for use in recitations)

• Status of Initial Assessment of Physical and Mechanical Properties of Graphite Grades for NGNP Appkications

  DOE Office of Scientific and Technical Information (OSTI.GOV)

  Strizak, Joe P; Burchell, Timothy D; Windes, Will

  2011-12-01

  Current candidate graphite grades for the core structures of NGNP include grades NBG-17, NBG-18, PCEA and IG-430. Both NBG-17 and NBG-18 are manufactured using pitch coke, and are vibrationally molded. These medium grain products are produced by SGL Carbon SAS (France). Tayo Tanso (Japan) produces IG-430 which is a petroleum coke, isostatically molded, nuclear grade graphite. And PCEA is a medium grain, extruded graphite produced by UCAR Carbon Co. (USA) from petroleum coke. An experimental program has been initiated to develop physical and mechanical properties data for these current candidate graphites. The results will be judged against the requirements formore » nuclear grade graphites set forth in ASTM standard D 7219-05 "Standard Specification for Isotropic and Near-isotropic Nuclear Graphites". Physical properties data including thermal conductivity and coefficient of thermal expansion, and mechanical properties data including tensile, compressive and flexural strengths will be obtained using the established test methods covered in D-7219 and ASTM C 781-02 "Standard Practice for Testing Graphite and Boronated Graphite Components for High-Temperature Gas-Cooled Nuclear Reactors". Various factors known to effect the properties of graphites will be investigated. These include specimen size, spatial location within a graphite billet, specimen orientation (ag and wg) within a billet, and billet-to-billet variations. The current status of the materials characterization program is reported herein. To date billets of the four graphite grades have been procured, and detailed cut up plans for obtaining the various specimens have been prepared. Particular attention has been given to the traceability of each specimen to its spatial location and orientation within a billet.« less

• The short-term stress response - Mother nature's mechanism for enhancing protection and performance under conditions of threat, challenge, and opportunity.

  PubMed

  Dhabhar, Firdaus S

  2018-03-26

  Our group has proposed that in contrast to chronic stress that can have harmful effects, the short-term (fight-or-flight) stress response (lasting for minutes to hours) is nature's fundamental survival mechanism that enhances protection and performance under conditions involving threat/challenge/opportunity. Short-term stress enhances innate/primary, adaptive/secondary, vaccine-induced, and anti-tumor immune responses, and post-surgical recovery. Mechanisms and mediators include stress hormones, dendritic cell, neutrophil, macrophage, and lymphocyte trafficking/function and local/systemic chemokine and cytokine production. Short-term stress may also enhance mental/cognitive and physical performance through effects on brain, musculo-skeletal, and cardiovascular function, reappraisal of threat/anxiety, and training-induced stress-optimization. Therefore, short-term stress psychology/physiology could be harnessed to enhance immuno-protection, as well as mental and physical performance. This review aims to provide a conceptual framework and targets for further investigation of mechanisms and conditions under which the protective/adaptive aspects of short-term stress/exercise can be optimized/harnessed, and for developing pharmacological/biobehavioral interventions to enhance health/healing, and mental/cognitive/physical performance. Copyright © 2018 Elsevier Inc. All rights reserved.

• Modelling Quasi-Periodic Pulsations in Solar and Stellar Flares

  NASA Astrophysics Data System (ADS)

  McLaughlin, J. A.; Nakariakov, V. M.; Dominique, M.; Jelínek, P.; Takasao, S.

  2018-02-01

  Solar flare emission is detected in all EM bands and variations in flux density of solar energetic particles. Often the EM radiation generated in solar and stellar flares shows a pronounced oscillatory pattern, with characteristic periods ranging from a fraction of a second to several minutes. These oscillations are referred to as quasi-periodic pulsations (QPPs), to emphasise that they often contain apparent amplitude and period modulation. We review the current understanding of quasi-periodic pulsations in solar and stellar flares. In particular, we focus on the possible physical mechanisms, with an emphasis on the underlying physics that generates the resultant range of periodicities. These physical mechanisms include MHD oscillations, self-oscillatory mechanisms, oscillatory reconnection/reconnection reversal, wave-driven reconnection, two loop coalescence, MHD flow over-stability, the equivalent LCR-contour mechanism, and thermal-dynamical cycles. We also provide a histogram of all QPP events published in the literature at this time. The occurrence of QPPs puts additional constraints on the interpretation and understanding of the fundamental processes operating in flares, e.g. magnetic energy liberation and particle acceleration. Therefore, a full understanding of QPPs is essential in order to work towards an integrated model of solar and stellar flares.

• Physical and mechanical properties of self-compacting concrete containing superplasticizer and metakaolin

  NASA Astrophysics Data System (ADS)

  Shahidan, Shahiron; Tayeh, Bassam A.; Jamaludin, A. A.; Bahari, N. A. A. S.; Mohd, S. S.; Zuki Ali, N.; Khalid, F. S.

  2017-11-01

  The development of concrete technology shows a variety of admixtures in concrete to produce special concrete. This includes the production of self-compacting concrete which is able to fill up all spaces, take formwork shapes and pass through congested reinforcement bars without vibrating or needing any external energy. In this study, the main objective is to compare the physical and mechanical properties of self-compacting concrete containing metakaolin with normal concrete. Four types of samples were produced to study the effect of metakaolin towards the physical and mechanical properties of self-compacting concrete where 0%, 5%, 10% and 15% of metakaolin were used as cement replacement. The physical properties were investigated using slump test for normal concrete and slump flow test for self-compacting concrete. The mechanical properties were tested for compressive strength and tensile strength. The findings of this study show that the inclusion of metakaolin as cement replacement can increase both compressive and tensile strength compared to normal concrete. The highest compressive strength was found in self-compacting concrete with 15% metakaolin replacement at 53.3 MPa while self-compacting concrete with 10% metakaolin replacement showed the highest tensile strength at 3.6 MPa. On top of that, the finishing or concrete surface of both cube and cylinder samples made of self-compacting concrete produced a smooth surface with the appearance of less honeycombs compared to normal concrete.

• Maternal Adverse Childhood Experience and Infant Health: Biomedical and Psychosocial Risks as Intermediary Mechanisms.

  PubMed

  Madigan, Sheri; Wade, Mark; Plamondon, Andre; Maguire, Jonathon L; Jenkins, Jennifer M

  2017-08-01

  To assess the mechanisms accounting for the transfer of risk from one generation to the next, especially as they relate to maternal adverse childhood experiences and infant physical and emotional health outcomes. Participants were 501 community mother-infant dyads recruited shortly after the birth and followed up at 18 months. Mothers retrospectively reported on their adverse childhood experiences. The main outcome measures were parent-reported infant physical health and emotional problems. Potential mechanisms of intergenerational transmission included cumulative biomedical risk (eg, prenatal and perinatal complications) and postnatal psychosocial risk (eg, maternal depression, single parenthood, marital conflict). Four or more adverse childhood experiences were related to a 2- and 5-fold increased risk of experiencing any biomedical or psychosocial risk, respectively. There was a linear association between number of adverse childhood experiences and extent of biomedical and psychosocial risk. Path analysis revealed that the association between maternal adverse childhood experiences and infant physical health operated specifically through cumulative biomedical risk, while the relationship between adverse childhood experiences and infant emotional health operated specifically through cumulative psychosocial risk. This pattern was not explained by maternal childhood disadvantage or current neighborhood poverty. Maternal adverse childhood experiences confer vulnerability to prenatal, perinatal, and postnatal psychosocial health. The association between adverse childhood experiences and offspring physical and emotional health operates through discrete intermediary mechanisms. Copyright © 2017 Elsevier Inc. All rights reserved.

• Methods to Implement Innovation and Entrepreneurship in Physics

  NASA Astrophysics Data System (ADS)

  Arion, Douglas

  2015-03-01

  The physics community is beginning to become aware of the benefits of entrepreneurship and innovation education: greater enrollments, improved students satisfaction, a wider range of interesting research problems, and the potential for greater return from more successful alumni. This talk will suggest a variety of mechanisms by which physics departments can include entrepreneurship and innovation content within their programs - without necessarily requiring earth-shattering changes to the curriculum. These approaches will thus make it possible for departments to get involved with entrepreneurship and innovation, and grow those components into vibrant activities for students and faculty.

• Embedded Process Modeling, Analogy-Based Option Generation and Analytical Graphic Interaction for Enhanced User-Computer Interaction: An Interactive Storyboard of Next Generation User-Computer Interface Technology. Phase 1

  DTIC Science & Technology

  1988-03-01

  structure of the interface is a mapping from the physical world [for example, the use of icons, which S have inherent meaning to users but represent...design alternatives. Mechanisms for linking the user to the computer include physical devices (keyboards), actions taken with the devices (keystrokes...VALUATION AIDES TEMLATEI IITCOM1I LATOR IACTICAL KNOWLEDGE ACGIUISITION MICNnII t 1 Fig. 9. INTACVAL. * OtJiCTs ARE PHYSICAL ENTITIES OR CONCEPTUAL EN

• Mechanical therapy for low back pain.

  PubMed

  Guild, Donald Grant

  2012-09-01

  Physical therapy and manual medicine for low back pain encompass many different treatment modalities. There is a vast variety of techniques that physical therapists commonly use in the treatment of low back pain. Some of the therapies include, but are certainly not limited to, education, exercise, lumbar traction, manual manipulation, application of heat, cryotherapy, and ultrasonography. Many of these approaches are discussed specifically in this article. Copyright © 2012. Published by Elsevier Inc.

• Physics, biology and the origin of life: the physicians' view.

  PubMed

  Goodman, Geoffrey; Gershwin, M Eric

  2011-12-01

  Physicians have a great interest in discussions of life and its origin, including life's persistence through successive cycles of self-replication under extreme climatic and man-made trials and tribulations. We review here the fundamental processes that, contrary to human intuition, life may be seen heuristically as an ab initio, fundamental process at the interface between the complementary forces of gravitation and quantum mechanics. Analogies can predict applications of quantum mechanics to human physiology in addition to that already being applied, in particular to aspects of brain activity and pathology. This potential will also extend eventually to, for example, autoimmunity, genetic selection and aging. We present these thoughts in perspective against a background of changes in some physical fundamentals of science, from the earlier times of the natural philosophers of medicine to the technological medical gurus of today. Despite the enormous advances in medical science, including integration of technological changes that have led to the newer clinical applications of magnetic resonance imaging and PET scans and of computerized drug design, there is an intellectual vacuum as to how the physics of matter became translated to the biology of life. The essence and future of medicine continue to lie in cautious, systematic and ethically bound practice and scientific research based on fundamental physical laws accepted as true until proven false.

• Development of a Hands-On Survey Course in the Physics of Living Systems

  NASA Astrophysics Data System (ADS)

  Matthews, Megan; Goldman, Daniel I.

  Due to the widespread availability and technological capabilities of modern smartphones, many biophysical systems can be investigated using easily accessible, low-cost, and/or ``homemade'' equipment. Our survey course is structured to provide students with an overview of research in the physics of living systems, emphasizing the interplay between measurement, mechanism, and modeling required to understand principles at the intersection of physics and biology. The course proceeds through seven modules each consisting of one week of lectures and one week of hands-on experiments, called ``microlabs''. Using smartphones, Arduinos, and 3D printed materials students create their own laboratory equipment, including a 150X van Leeuwenhoek microscope, a shaking incubator, and an oscilloscope, and then use them to study biological systems ranging in length scales from nanometers to meters. These systems include population dynamics of rotifer/algae cultures, experimental evolution of multicellularity in budding yeast, and the bio- & neuromechanics involved in animal locomotion, among others. In each module, students are introduced to fundamental biological and physical concepts as well as theoretical and computational tools (nonlinear dynamics, molecular dynamics simulation, and statistical mechanics). At the end of the course, students apply these concepts and tools to the creation of their own microlab that integrates hands-on experimentation and modeling in the study of their chosen biophysical system.

• Physical activity and telomere length: Impact of aging and potential mechanisms of action

  PubMed Central

  Arsenis, Nicole C.; You, Tongjian; Ogawa, Elisa F.; Tinsley, Grant M.; Zuo, Li

  2017-01-01

  Telomeres protect the integrity of information-carrying DNA by serving as caps on the terminal portions of chromosomes. Telomere length decreases with aging, and this contributes to cell senescence. Recent evidence supports that telomere length of leukocytes and skeletal muscle cells may be positively associated with healthy living and inversely correlated with the risk of several age-related diseases, including cancer, cardiovascular disease, obesity, diabetes, chronic pain, and stress. In observational studies, higher levels of physical activity or exercise are related to longer telomere lengths in various populations, and athletes tend to have longer telomere lengths than non-athletes. This relationship is particularly evident in older individuals, suggesting a role of physical activity in combating the typical age-induced decrements in telomere length. To date, a small number of exercise interventions have been executed to examine the potential influence of chronic exercise on telomere length, but these studies have not fully established such relationship. Several potential mechanisms through which physical activity or exercise could affect telomere length are discussed, including changes in telomerase activity, oxidative stress, inflammation, and decreased skeletal muscle satellite cell content. Future research is needed to mechanistically examine the effects of various modalities of exercise on telomere length in middle-aged and older adults, as well as in specific clinical populations. PMID:28410238

• Physical activity and telomere length: Impact of aging and potential mechanisms of action.

  PubMed

  Arsenis, Nicole C; You, Tongjian; Ogawa, Elisa F; Tinsley, Grant M; Zuo, Li

  2017-07-04

  Telomeres protect the integrity of information-carrying DNA by serving as caps on the terminal portions of chromosomes. Telomere length decreases with aging, and this contributes to cell senescence. Recent evidence supports that telomere length of leukocytes and skeletal muscle cells may be positively associated with healthy living and inversely correlated with the risk of several age-related diseases, including cancer, cardiovascular disease, obesity, diabetes, chronic pain, and stress. In observational studies, higher levels of physical activity or exercise are related to longer telomere lengths in various populations, and athletes tend to have longer telomere lengths than non-athletes. This relationship is particularly evident in older individuals, suggesting a role of physical activity in combating the typical age-induced decrements in telomere length. To date, a small number of exercise interventions have been executed to examine the potential influence of chronic exercise on telomere length, but these studies have not fully established such relationship. Several potential mechanisms through which physical activity or exercise could affect telomere length are discussed, including changes in telomerase activity, oxidative stress, inflammation, and decreased skeletal muscle satellite cell content. Future research is needed to mechanistically examine the effects of various modalities of exercise on telomere length in middle-aged and older adults, as well as in specific clinical populations.

• The Mechanical Properties of Nanowires

  PubMed Central

  Wang, Shiliang; Shan, Zhiwei

  2017-01-01

  Applications of nanowires into future generation nanodevices require a complete understanding of the mechanical properties of the nanowires. A great research effort has been made in the past two decades to understand the deformation physics and mechanical behaviors of nanowires, and to interpret the discrepancies between experimental measurements and theoretical predictions. This review focused on the characterization and understanding of the mechanical properties of nanowires, including elasticity, plasticity, anelasticity and strength. As the results from the previous literature in this area appear inconsistent, a critical evaluation of the characterization techniques and methodologies were presented. In particular, the size effects of nanowires on the mechanical properties and their deformation mechanisms were discussed. PMID:28435775

• Accelerated testing of space batteries

  NASA Technical Reports Server (NTRS)

  Mccallum, J.; Thomas, R. E.; Waite, J. H.

  1973-01-01

  An accelerated life test program for space batteries is presented that fully satisfies empirical, statistical, and physical criteria for validity. The program includes thermal and other nonmechanical stress analyses as well as mechanical stress, strain, and rate of strain measurements.

• NASA Tech Briefs, May 1998. Volume 22, No. 5

  NASA Technical Reports Server (NTRS)

  1998-01-01

  Topics include: special coverage on advanced composites, plastics and metals, electronic components and circuits, electronic systems, physical sciences, computer software, mechanics, machinery/automation, manufacturing/fabrication book and reports, and a special section of Electronics Tech Briefs.

• NASA Tech Briefs, October 2001. Volume 25, No. 10

  NASA Technical Reports Server (NTRS)

  2001-01-01

  Topics include: special coverage section on composites and plastics, electronic components and systems, software, mechanics, physical sciences, information sciences, book and reports, and a special sections of Photonics Tech Briefs and Motion Control Tech Briefs.

• NASA Tech Briefs, February 2002. Volume 26, No. 2

  NASA Technical Reports Server (NTRS)

  2002-01-01

  Topics include:a technology focus on computers, electronic components and systems, software, materials, mechanics,physical sciences machinery, manufacturing/fabrication, mathematics, book and reports, motion control tech briefs and a special section on Photonics Tech Briefs.

• NASA Tech Briefs, January 1999. Volume 23, Mp/ 1

  NASA Technical Reports Server (NTRS)

  1999-01-01

  Topics include: special coverage sections on sensors and data acquisition and sections on electronic components and circuits, electronic software, materials, mechanics, bio-medical physical sciences, book and reports, and a special section of Photonics Tech Briefs.

• NASA Tech Briefs, August 2000. Volume 24, No. 8

  NASA Technical Reports Server (NTRS)

  2000-01-01

  Topics include: Simulation/Virtual Reality; Test and Measurement; Computer-Aided Design and Engineering; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Medical Design.

NASA Tech Briefs, June 1995. Volume 19, No. 6

NASA Technical Reports Server (NTRS)

1995-01-01

Topics include: communications technology, electronic components and circuits, electronic systems, physical sciences, materials, computer programs, mechanics, machinery, manufacturing/fabrication, mathematics and information sciences, life sciences, books and reports, a special section of laser Tech Briefs.

Improvement of physical properties of calcium phosphate cement by elastin-like polypeptide supplementation.

PubMed

Jang, Ji-Hyun; Shin, Sumi; Kim, Hyun-Jung; Jeong, Jinyoung; Jin, Hyo-Eon; Desai, Malav S; Lee, Seung-Wuk; Kim, Sun-Young

2018-03-26

Calcium phosphate cements (CPCs) are synthetic bioactive cements widely used as hard tissue substitutes. Critical limitations of use include their poor mechanical properties and poor anti-washout behaviour. To address those limitations, we combined CPC with genetically engineered elastin-like polypeptides (ELPs). We investigated the effect of the ELPs on the physical properties and biocompatibility of CPC by testing ELP/CPC composites with various liquid/powder ratios. Our results show that the addition of ELPs improved the mechanical properties of the CPC, including the microhardness, compressive strength, and washout resistance. The biocompatibility of ELP/CPC composites was also comparable to that of the CPC alone. However, supplementing CPC with ELPs functionalized with octaglutamate as a hydroxyapatite binding peptide increased the setting time of the cement. With further design and modification of our biomolecules and composites, our research will lead to products with diverse applications in biology and medicine.

The Six Core Theories of Modern Physics

NASA Astrophysics Data System (ADS)

Stevens, Charles F.

1996-09-01

Charles Stevens, a prominent neurobiologist who originally trained as a biophysicist (with George Uhlenbeck and Mark Kac), wrote this book almost by accident. Each summer he found himself reviewing key areas of physics that he had once known and understood well, for use in his present biological research. Since there was no book, he created his own set of notes, which formed the basis for this brief, clear, and self-contained summary of the basic theoretical structures of classical mechanics, electricity and magnetism, quantum mechanics, statistical physics, special relativity, and quantum field theory. The Six Core Theories of Modern Physics can be used by advanced undergraduates or beginning graduate students as a supplement to the standard texts or for an uncluttered, succinct review of the key areas. Professionals in such quantitative sciences as chemistry, engineering, computer science, applied mathematics, and biophysics who need to brush up on the essentials of a particular area will find most of the required background material, including the mathematics.

Coronal magnetohydrodynamic waves and oscillations: observations and quests.

PubMed

Aschwanden, Markus J

2006-02-15

Coronal seismology, a new field of solar physics that emerged over the last 5 years, provides unique information on basic physical properties of the solar corona. The inhomogeneous coronal plasma supports a variety of magnetohydrodynamics (MHD) wave modes, which manifest themselves as standing waves (MHD oscillations) and propagating waves. Here, we briefly review the physical properties of observed MHD oscillations and waves, including fast kink modes, fast sausage modes, slow (acoustic) modes, torsional modes, their diagnostics of the coronal magnetic field, and their physical damping mechanisms. We discuss the excitation mechanisms of coronal MHD oscillations and waves: the origin of the exciter, exciter propagation, and excitation in magnetic reconnection outflow regions. Finally, we consider the role of coronal MHD oscillations and waves for coronal heating, the detectability of various MHD wave types, and we estimate the energies carried in the observed MHD waves and oscillations: Alfvénic MHD waves could potentially provide sufficient energy to sustain coronal heating, while acoustic MHD waves fall far short of the required coronal heating rates.

Captured key electrical safety lockout system

DOEpatents

Darimont, Daniel E.

1995-01-01

A safety lockout apparatus for an electrical circuit includes an electrical switch, a key, a lock and a blocking mechanism. The electrical switch is movable between an ON position at which the electrical circuit is energized and an OFF position at which the electrical circuit is deactivated. The lock is adapted to receive the key and is rotatable among a plurality of positions by the key. The key is only insertable and removable when the lock is at a preselected position. The lock is maintained in the preselected position when the key is removed from the lock. The blocking mechanism physically maintains the switch in its OFF position when the key is removed from the lock. The blocking mechanism preferably includes a member driven by the lock between a first position at which the electrical switch is movable between its ON and OFF positions and a second position at which the member physically maintains the electrical switch in its OFF position. Advantageously, the driven member's second position corresponds to the preselected position at which the key can be removed from and inserted into the lock.

Captured key electrical safety lockout system

DOEpatents

Darimont, D.E.

1995-10-31

A safety lockout apparatus for an electrical circuit includes an electrical switch, a key, a lock and a blocking mechanism. The electrical switch is movable between an ON position at which the electrical circuit is energized and an OFF position at which the electrical circuit is deactivated. The lock is adapted to receive the key and is rotatable among a plurality of positions by the key. The key is only insertable and removable when the lock is at a preselected position. The lock is maintained in the preselected position when the key is removed from the lock. The blocking mechanism physically maintains the switch in its OFF position when the key is removed from the lock. The blocking mechanism preferably includes a member driven by the lock between a first position at which the electrical switch is movable between its ON and OFF positions and a second position at which the member physically maintains the electrical switch in its OFF position. Advantageously, the driven member`s second position corresponds to the preselected position at which the key can be removed from and inserted into the lock. 7 figs.

Physics and the canalization of morphogenesis: a grand challenge in organismal biology

PubMed Central

von Dassow, Michelangelo; Davidson, Lance A.

2011-01-01

Morphogenesis takes place in a background of organism-to-organism and environmental variation. Therefore, a fundamental question in the study of morphogenesis is how the mechanical processes of tissue movement and deformation are affected by that variability, and in turn, how the mechanics of the system modulates phenotypic variation. We highlight a few key factors, including environmental temperature, embryo size, and environmental chemistry that might perturb the mechanics of morphogenesis in natural populations. Then we discuss several ways in which mechanics – including feedback from mechanical cues – might influence intra-specific variation in morphogenesis. To understand morphogenesis it will be necessary to consider whole-organism, environment, and evolutionary scales because these larger scales present the challenges that developmental mechanisms have evolved to cope with. Studying the variation organisms express and the variation organisms experience will aid in deciphering the causes of birth defects. PMID:21750364

Clinical Case Reporting in the Peer-Reviewed Physical Therapy Literature: Time to Move Toward Functioning.

PubMed

Davenport, Todd E

2015-12-01

Physical therapists increasingly are contributing clinical case reports to the health literature, which form the basis for higher quality evidence that has been incorporated into clinical practice guidelines. Yet, few resources exist to assist physical therapists with the basic mechanics and quality standards of producing a clinical case report. This situation is further complicated by the absence of uniform standards for quality in case reporting. The importance of including a concise yet comprehensive description of patient functioning in all physical therapy case reports suggest the potential appropriateness of basing quality guidelines on the World Health Organization's International Classification of Functioning Disability and Health (ICF) model. The purpose of this paper is to assist physical therapists in creating high-quality clinical case reports for the peer-reviewed literature using the ICF model as a guiding framework. Along these lines, current recommendations related to the basic mechanics of writing a successful clinical case report are reviewed, as well and a proposal for uniform clinical case reporting requirements is introduced with the aim to improve the quality and feasibility of clinical case reporting in physical therapy that are informed by the ICF model. Copyright © 2013 John Wiley & Sons, Ltd.

Einstein's equivalence principle in quantum mechanics revisited

NASA Astrophysics Data System (ADS)

Nauenberg, Michael

2016-11-01

The gravitational equivalence principle in quantum mechanics is of considerable importance, but it is generally not included in physics textbooks. In this note, we present a precise quantum formulation of this principle and comment on its verification in a neutron diffraction experiment. The solution of the time dependent Schrödinger equation for this problem also gives the wave function for the motion of a charged particle in a homogeneous electric field, which is also usually ignored in textbooks on quantum mechanics.

Expendable Launch Vehicles Briefing and Basic Rocketry Physics

NASA Technical Reports Server (NTRS)

Delgado, Luis G.

2010-01-01

This slide presentation is composed of two parts. The first part shows pictures of launch vehicles and lift offs or in the case of the Pegasus launch vehicle separations. The second part discusses the basic physics of rocketry, starting with Newton's three physical laws that form the basis for classical mechanics. It includes a review of the basic equations that define the physics of rocket science, such as total impulse, specific impulse, effective exhaust velocity, mass ratio, propellant mass fraction, and the equations that combine to arrive at the thrust of the rocket. The effect of atmospheric pressure is reviewed, as is the effect of propellant mix on specific impulse.

30 years of Physics Education Research at the University of Washington

NASA Astrophysics Data System (ADS)

Shaffer, Peter S.

2017-01-01

Over the past 30 years, members of the UW Physics Education Group have examined student learning in courses serving a wide range of populations. Most of the focus has been on elementary, middle, and high school teachers and students in introductory university physics courses, but more recently, the effort has expanded to include physics majors in upper-division courses on quantum mechanics and electrodynamics. In general, the group has taken a practical approach that focuses on identifying instructional strategies that are effective at promoting conceptual understanding and student reasoning ability. Examples will be drawn from across these courses to illustrate common themes and connections.

Physical and antibacterial properties of açaí edible films formulated with thyme essential oil and apple skin polyphenols.

PubMed

Espitia, Paula J P; Avena-Bustillos, Roberto J; Du, Wen-Xian; Chiou, Bor-Sen; Williams, Tina G; Wood, Delilah; McHugh, Tara H; Soares, Nilda F F

2014-05-01

Thyme essential oil (TEO) and apple skin polyphenols (ASP) are natural compounds considered as generally recognized as safe by FDA, with biological effects against bacteria and fungi. This work aimed to evaluate physical and antimicrobial properties of açaí edible films formulated with TEO and ASP at 3% and 6% (w/w) individually or combined at 3% (w/w) each. Physical properties studied include mechanical resistance, water vapor permeability (WVP), color, and thermal resistance. Antimicrobial activity against Listeria monocytogenes was determined using the overlay diffusion test. Addition of ASP resulted in improved mechanical properties. TEO at 6% (w/w) resulted in increased elongation. ASP films had significant higher WVP than control film. ASP films were lighter and had more red color than other films. Incorporation of ASP resulted in improved film thermal stability, whereas TEO caused rapid thermal decomposition. Presence of clusters was observed on the surface of films. Addition of ASP resulted in a smoother surface, whereas addition of TEO led to the formation of crater-like pits on the film surface. Açaí edible film incorporated with 6% (w/w) TEO presented the highest antimicrobial activity. However, both antimicrobials are necessary in the açaí films in order to obtain edible films with suitable physical-mechanical properties. The results of the present study showed that TEO and ASP can be used to prepare açaí edible films with adequate physical-mechanical properties and antimicrobial activity for food applications by direct contact. Developed açaí edible films presented antimicrobial activity against L. monocytogenes and good physical-mechanical properties, showing the potential use of açaí edible films in food preservation. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

The evaluation of physical exam findings in patients assessed for suspected burn inhalation injury.

PubMed

Ching, Jessica A; Shah, Jehan L; Doran, Cody J; Chen, Henian; Payne, Wyatt G; Smith, David J

2015-01-01

The purpose of this investigation was to evaluate the utility of singed nasal hair (SN), carbonaceous sputum (CS), and facial burns (FB) as indicators of burn inhalation injury, when compared to the accepted standard of bronchoscopic diagnosis of inhalation injury. An institutional review board approved, retrospective review was conducted. All patients were suspected to have burn inhalation injury and subsequently underwent bronchoscopic evaluation. Data collected included: percent burn TBSA, burn injury mechanism, admission physical exam findings (SN, CS, FB), and bronchoscopy findings. Thirty-five males and twelve females met inclusion criteria (n = 47). Bronchoscopy was normal in 31 patients (66%). Data were analyzed as all patients and in subgroups according to burn TBSA and an enclosed space mechanism of injury. Physical exam findings (SN, CS, FB) were evaluated individually and in combination. Overall, the sensitivities, specificities, positive predictive values, and negative predictive values calculated were poor and inconsistent, and they did not improve within subgroup analysis or when physical findings were combined. Further statistical analysis suggested the physical findings, whether in isolation or in combination, have poor discrimination between patients that have and do not have inhalation injury (AUC < 0.7, P > .05) and poor agreement with the diagnosis made by bronchoscopy (κ < 0.4, P > .05). This remained true in the subgroup analysis as well. Our data demonstrated the findings of SN, CS, and FB are unreliable evidence for inhalation injury, even in the context of an enclosed space mechanism of injury. Thus, these physical findings are not absolute indicators for intubation and should be interpreted as one component of the history and physical.

Nuclear physics with antiprotons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dover, C.B.

1984-01-01

Transparencies of an invited talk presented at the Nashville meeting of the American Physical Society, October 18-20, 1984, are included. Topics include: (1) Salient features of two-body N anti N interactions (N anti N reversible NN, annihilation mechanisms (quark models), and optical model phenomenology); (2) anti N-nucleus interactions - elastic, inelastic, etc. (new cross section data, optical potentials, signatures of spin-isospin dependence of N anti N force, and (anti p, p) reactions); and (3) anti N-nucleus annihilation processes (features of cascade or fluid dynamics calculations, searches for baryonium and other exotics, meson interferometry, and (anti p, NN) reactions. (WHK)

How far do EPR-Bell experiments constrain physical collapse theories?

NASA Astrophysics Data System (ADS)

Leggett, A. J.

2007-03-01

A class of theories alternative to standard quantum mechanics, including that of Ghirardi et al ('GRWP'), postulates that when a quantum superposition becomes amplified to the point that the superposed states reach some level of 'macroscopic distinctness', then some non-quantum-mechanical principle comes into play and realizes one or other of the two macroscopic outcomes. Without specializing to any particular theory of this class, I ask how far such 'macrorealistic' theories are generically constrained, if one insists that the physical reduction process should respect Einstein locality, by the results of existing EPR-Bell experiments. I conclude that provided one does not demand that the prescription for reduction respects Lorentz invariance, at least some theories of this type, while in principle inevitably making some predictions that conflict with those of standard quantum mechanics, are not refuted by any existing experiment.

Space physics education via examples in the undergraduate physics curriculum

NASA Astrophysics Data System (ADS)

Martin, R.; Holland, D. L.

2011-12-01

The field of space physics is rich with examples of basic physics and analysis techniques, yet it is rarely seen in physics courses or textbooks. As space physicists in an undergraduate physics department we like to use research to inform teaching, and we find that students respond well to examples from magnetospheric science. While we integrate examples into general education courses as well, this talk will focus on physics major courses. Space physics examples are typically selected to illustrate a particular concept or method taught in the course. Four examples will be discussed, from an introductory electricity and magnetism course, a mechanics/nonlinear dynamics course, a computational physics course, and a plasma physics course. Space physics provides examples of many concepts from introductory E&M, including the application of Faraday's law to terrestrial magnetic storm effects and the use of the basic motion of charged particles as a springboard to discussion of the inner magnetosphere and the aurora. In the mechanics and nonlinear dynamics courses, the motion of charged particles in a magnetotail current sheet magnetic field is treated as a Newtonian dynamical system, illustrating the Poincaré surface-of-section technique, the partitioning of phase space, and the KAM theorem. Neural network time series analysis of AE data is used as an example in the computational physics course. Finally, among several examples, current sheet particle dynamics is utilized in the plasma physics course to illustrate the notion of adiabatic/guiding center motion and the breakdown of the adiabatic approximation. We will present short descriptions of our pedagogy and student assignments in this "backdoor" method of space physics education.

Characterizing the Physical and Thermal Properties of Planetary Regolith at Low Temperatures

NASA Technical Reports Server (NTRS)

Mantovani, James G.; Swanger, Adam; Townsend, Ivan I., III; Sibille, Laurent; Galloway, Gregory

2014-01-01

The success or failure of in-situ resource utilization for planetary surface exploration-whether for science, colonization, or commercialization-relies heavily on the design and implementation of systems that can effectively process planetary regolith and exploit its potential benefits. In most cases, this challenge necessarily includes the characterization of regolith properties at low temperatures (cryogenic). None of the nearby solar system destinations of interest, such as the moon, Mars and asteroids, possess a sufficient atmosphere to sustain the consistently "high" surface temperatures found on Earth. Therefore, they can experience permanent cryogenic temperatures or dramatic cyclical changes in surface temperature. Characterization of physical properties (e.g., specific heat, thermal and electrical conductivity) over the entire temperature profile is important when planning a mission to a planetary surface; however, the impact on mechanical properties due to the introduction of icy deposits must also be explored in order to devise effective and robust excavation technologies. The Granular Mechanics and Regolith Operations Laboratory and the Cryogenics Test Laboratory at NASA Kennedy Space Center are developing technologies and experimental methods to address these challenges and to aid in the characterization of the physical and mechanical properties of regolith at cryogenic temperatures. This paper will review the current state of knowledge concerning planetary regolith at low temperature, including that of icy regolith, and describe efforts to manipulate icy regolith through novel penetration and excavation techniques.

Summary and Prospect.

PubMed

Wei, Zhengde; Chen, Xueli; Zhang, Xiaochu

2017-01-01

In this chapter, the main content is to summarize the similarities and differences between substance and non-substance addictions in several aspects, involving definition, mechanisms, diagnosis and treatment. We try to display the complete picture of addictions in a brief but comprehensive way. Mechanism includes molecule and neural circuit, genetics, neuroimaging and cognitive psychology; diagnosis includes diagnostic criterion, diagnostic scales, biochemical diagnosis and new diagnostic techniques; treatment includes drug therapy, physical therapy, traditional Chinese medical therapy, nutrition support therapy, psychotherapy and cognitive-behavioral therapy. This chapter also covers some prospect which will induct future studies on addiction. We aim at providing the researchers and graduate students with better understanding of substance and non-substance addictions.

The physical and physiological effects of vacuum massage on the different skin layers: a current status of the literature.

PubMed

Moortgat, Peter; Anthonissen, Mieke; Meirte, Jill; Van Daele, Ulrike; Maertens, Koen

2016-01-01

Vacuum massage is a non-invasive mechanical massage technique performed with a mechanical device that lifts the skin by means of suction, creates a skin fold and mobilises that skin fold. In the late 1970s, this therapy was introduced to treat traumatic or burn scars. Although vacuum massage was invented to treat burns and scars, one can find very little literature on the effects of this intervention. Therefore, the aim of this review is to present an overview of the available literature on the physical and physiological effects of vacuum massage on epidermal and dermal skin structures in order to find the underlying working mechanisms that could benefit the healing of burns and scars. The discussion contains translational analysis of the results and provides recommendations for future research on the topic. An extended search for publications was performed using PubMed, Web of Science and Google Scholar. Two authors independently identified and checked each study against the inclusion criteria. Nineteen articles were included in the qualitative synthesis. The two most reported physical effects of vacuum massage were improvement of the tissue hardness and the elasticity of the skin. Besides physical effects, a variety of physiological effects are reported in literature, for example, an increased number of fibroblasts and collagen fibres accompanied by an alteration of fibroblast phenotype and collagen orientation. Little information was found on the decrease of pain and itch due to vacuum massage. Although vacuum massage initially had been developed for the treatment of burn scars, this literature review found little evidence for the efficacy of this treatment. Variations in duration, amplitude or frequency of the treatment have a substantial influence on collagen restructuring and reorientation, thus implying possible beneficial influences on the healing potential by mechanotransduction pathways. Vacuum massage may release the mechanical tension associated with scar retraction and thus induce apoptosis of myofibroblasts. Suggestions for future research include upscaling the study design, investigating the molecular pathways and dose dependency, comparing effects in different stages of repair, including evolutive parameters and the use of more objective assessment tools.

Physical Activity and Change in Mammographic Density

PubMed Central

Conroy, Shannon M.; Butler, Lesley M.; Harvey, Danielle; Gold, Ellen B.; Sternfeld, Barbara; Oestreicher, Nina; Greendale, Gail A.; Habel, Laurel A.

2010-01-01

One potential mechanism by which physical activity may protect against breast cancer is by decreasing mammographic density. Percent mammographic density, the proportion of dense breast tissue area to total breast area, declines with age and is a strong risk factor for breast cancer. The authors hypothesized that women who were more physically active would have a greater decline in percent mammographic density with age, compared with less physically active women. The authors tested this hypothesis using longitudinal data (1996–2004) from 722 participants in the Study of Women's Health Across the Nation (SWAN), a multiethnic cohort of women who were pre- and early perimenopausal at baseline, with multivariable, repeated-measures linear regression analyses. During an average of 5.6 years, the mean annual decline in percent mammographic density was 1.1% (standard deviation = 0.1). A 1-unit increase in total physical activity score was associated with a weaker annual decline in percent mammographic density by 0.09% (standard error = 0.03; P = 0.01). Physical activity was inversely associated with the change in nondense breast area (P < 0.01) and not associated with the change in dense breast area (P = 0.17). Study results do not support the hypothesis that physical activity reduces breast cancer through a mechanism that includes reduced mammographic density. PMID:20354074

Otto Laporte Award Talk - In light of Fluid Mechanics

NASA Astrophysics Data System (ADS)

Gharib, Morteza

2015-11-01

Fluid mechanics, in its inherent non-linear beauty, has been its own laboratory, testing our perseverance and dedication to a branch of science that, despite its perceived maturity, still has many surprises to offer. For many of us, the study of fluid flow has been our path to understanding the complexity of nature. My journey has taken me through many interesting projects including the development of new visualization tools, scrutinizing the rhythms of the human heart, observing flow vortices and studying the dynamics of soap films. But this lecture is mainly devoted to a new example of my research activities where light and flow physics interweave to display another intriguing multi-physics beauty of nature.

Epigenetics and lifestyle

PubMed Central

Alegría-Torres, Jorge Alejandro; Baccarelli, Andrea; Bollati, Valentina

2013-01-01

The concept of “lifestyle” includes different factors such as nutrition, behavior, stress, physical activity, working habits, smoking and alcohol consumption. Increasing evidence shows that environmental and lifestyle factors may influence epigenetic mechanisms, such as DNA methylation, histone acetylation and microRNA expression. Several lifestyle factors have been identified that might modify epigenetic patterns, such as diet, obesity, physical activity, tobacco smoking, alcohol consumption, environmental pollutants, psychological stress, and working on night shifts. Most studies conducted so far have been centered on DNA methylation, whereas only a few investigations have studied lifestyle factors in relation to histone modifications and miRNAs. Here, we review current evidence indicating that lifestyle factors might affect human health via epigenetic mechanisms. PMID:22122337

Epigenetics and lifestyle.

PubMed

Alegría-Torres, Jorge Alejandro; Baccarelli, Andrea; Bollati, Valentina

2011-06-01

The concept of 'lifestyle' includes different factors such as nutrition, behavior, stress, physical activity, working habits, smoking and alcohol consumption. Increasing evidence shows that environmental and lifestyle factors may influence epigenetic mechanisms, such as DNA methylation, histone acetylation and miRNA expression. It has been identified that several lifestyle factors such as diet, obesity, physical activity, tobacco smoking, alcohol consumption, environmental pollutants, psychological stress and working on night shifts might modify epigenetic patterns. Most of the studies conducted so far have been centered on DNA methylation, whereas only a few investigations have studied lifestyle factors in relation to histone modifications and miRNAs. This article reviews current evidence indicating that lifestyle factors might affect human health via epigenetic mechanisms.

NASA Tech Briefs, September 1998. Volume 22, No. 9

NASA Technical Reports Server (NTRS)

1998-01-01

Topics include: special coverage on data acquisition, also, electronic components and circuits, electronic systems, software, materials, mechanics, machinery/automation, physical sciences, information sciences, This issue contains a special sections of Electronics Tech Briefs and Motion Control Tech Briefs.

NASA Tech Briefs, February 1989. Volume 13, No. 2

NASA Technical Reports Server (NTRS)

1989-01-01

This issue contains a special feature on shaping the future with Ceramics. Other topics include: Electronic Components & and Circuits. Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Fabrication Technology, Mathematics and Information Sciences, and Life Sciences,

Microgravity

NASA Image and Video Library

2001-01-24

Interior of a Spacehab module showing the type of rack mounting that will be used, and crew working space that will be available, on the STS-107 Research 1 mission in 2002. Experiments plarned for the mission include soil mechanics, combustion physics, and cell science.

NASA Tech Briefs, July 2000. Volume 24, No. 7

NASA Technical Reports Server (NTRS)

2000-01-01

Topics covered include: Data Acquisition; Computer-Aided Design and Engineering; Electronic Components and Circuits; Electronic Systems; Test and Measurement; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports.

Friction, wear, and lubrication in vacuum

NASA Technical Reports Server (NTRS)

Buckley, D. H.

1971-01-01

A review of studies and observations on the friction, wear, and lubrication behavior of materials in a vacuum environment is presented. The factors that determine and influence friction and wear are discussed. They include topographical, physical, mechanical, and the chemical nature of the surface. The effects of bulk properties such as deformation characteristics, fracture behavior, and structure are included.

NASA Tech Briefs, August 1995. Volume 19, No. 8

NASA Technical Reports Server (NTRS)

1995-01-01

There is a special focus on computer graphics and simulation in this issue. Topics covered include : Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer programs, Mechanics; Machinery; Fabrication Technology; and Mathematics and Information Sciences. There is a section on for Laser Technology, which includes a feature on Moving closer to the suns power.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diaz Cruz, J. Lorenzo

This paper intends to review the subject of Higgs Physics. I start from the early stages, including its phenomenology and the current expectations for the possible Higgs discovery at the coming LHC. Then, I discuss the proposals for new physics that attempt to solve the hierarchy problem, where the Higgs boson can be either a fundamental or composite field. Finally, I also comment on the hardest questions, namely on the possible connection between the Higgs mechanism, the Standard Model parameters and gravity.

Replicating effective pedagogical approaches from introductory physics to improve student learning of quantum mechanics

NASA Astrophysics Data System (ADS)

Sayer, Ryan Thomas

Upper-level undergraduate students entering a quantum mechanics (QM) course are in many ways similar to students entering an introductory physics course. Numerous studies have investigated the difficulties that novices face in introductory physics as well as the pedagogical approaches that are effective in helping them overcome those difficulties. My research focuses on replicating effective approaches and instructional strategies used in introductory physics courses to help advanced students in an upper-level QM course. I have investigated the use of Just-in-time Teaching (JiTT) and peer discussion involving clicker questions in an upper-level quantum mechanics course. The JiTT approach including peer discussions was effective in helping students overcome their difficulties and improve their understanding of QM concepts. Learning tools, such as a Quantum Interactive Learning Tutorial (QuILT) based on the Doubleslit Experiment (DSE) which I helped develop, have been successful in helping upper-level undergraduate students improve their understanding of QM. Many students have also demonstrated the ability to transfer knowledge from a QuILT based on the Mach-Zehnder interferometer while working on the DSE QuILT. In addition, I have been involved in implementing research-based activities during our semester-long professional development course for teaching assistants (TAs). In one intervention, TAs were asked to grade student solutions to introductory physics problems first using their choice of method, then again using a rubric designed to promote effective problem-solving approaches, then once more at the end of the semester using their choice of method. This intervention found that many TAs have ingrained beliefs about the purposes of grading which include placing the burden of proof on the instructor as well as a belief that grading cannot serve as a formative assessment. I also compared TAs grading practices and considerations when grading student solutions to QM problems versus when grading student solutions to introductory physics. Many TAs penalized students for not explicating the problem solving process more often in the QM context than in the introductory physics context. The implications of these interventions for promoting student learning in QM are discussed.

BOOK REVIEW: Mathematica for Theoretical Physics: Electrodynamics, Quantum Mechanics, General Relativity and Fractals

NASA Astrophysics Data System (ADS)

Heusler, Stefan

2006-12-01

The main focus of the second, enlarged edition of the book Mathematica for Theoretical Physics is on computational examples using the computer program Mathematica in various areas in physics. It is a notebook rather than a textbook. Indeed, the book is just a printout of the Mathematica notebooks included on the CD. The second edition is divided into two volumes, the first covering classical mechanics and nonlinear dynamics, the second dealing with examples in electrodynamics, quantum mechanics, general relativity and fractal geometry. The second volume is not suited for newcomers because basic and simple physical ideas which lead to complex formulas are not explained in detail. Instead, the computer technology makes it possible to write down and manipulate formulas of practically any length. For researchers with experience in computing, the book contains a lot of interesting and non-trivial examples. Most of the examples discussed are standard textbook problems, but the power of Mathematica opens the path to more sophisticated solutions. For example, the exact solution for the perihelion shift of Mercury within general relativity is worked out in detail using elliptic functions. The virial equation of state for molecules' interaction with Lennard-Jones-like potentials is discussed, including both classical and quantum corrections to the second virial coefficient. Interestingly, closed solutions become available using sophisticated computing methods within Mathematica. In my opinion, the textbook should not show formulas in detail which cover three or more pages—these technical data should just be contained on the CD. Instead, the textbook should focus on more detailed explanation of the physical concepts behind the technicalities. The discussion of the virial equation would benefit much from replacing 15 pages of Mathematica output with 15 pages of further explanation and motivation. In this combination, the power of computing merged with physical intuition would be of benefit even for newcomers. In summary, this book shows in a convincing manner how classical problems in physics can be attacked with modern computing technology. The second volume is interesting for experienced users of Mathematica. For students, the textbook can be very useful in combination with a seminar.

Computational studies of physical properties of Nb-Si based alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ouyang, Lizhi

2015-04-16

The overall goal is to provide physical properties data supplementing experiments for thermodynamic modeling and other simulations such as phase filed simulation for microstructure and continuum simulations for mechanical properties. These predictive computational modeling and simulations may yield insights that can be used to guide materials design, processing, and manufacture. Ultimately, they may lead to usable Nb-Si based alloy which could play an important role in current plight towards greener energy. The main objectives of the proposed projects are: (1) developing a first principles method based supercell approach for calculating thermodynamic and mechanic properties of ordered crystals and disordered latticesmore » including solid solution; (2) application of the supercell approach to Nb-Si base alloy to compute physical properties data that can be used for thermodynamic modeling and other simulations to guide the optimal design of Nb-Si based alloy.« less

Cyberspatial mechanics.

PubMed

Bayne, Jay S

2008-06-01

In support of a generalization of systems theory, this paper introduces a new approach in modeling complex distributed systems. It offers an analytic framework for describing the behavior of interactive cyberphysical systems (CPSs), which are networked stationary or mobile information systems responsible for the real-time governance of physical processes whose behaviors unfold in cyberspace. The framework is predicated on a cyberspace-time reference model comprising three spatial dimensions plus time. The spatial domains include geospatial, infospatial, and sociospatial references, the latter describing relationships among sovereign enterprises (rational agents) that choose voluntarily to organize and interoperate for individual and mutual benefit through geospatial (physical) and infospatial (logical) transactions. Of particular relevance to CPSs are notions of timeliness and value, particularly as they relate to the real-time governance of physical processes and engagements with other cooperating CPS. Our overarching interest, as with celestial mechanics, is in the formation and evolution of clusters of cyberspatial objects and the federated systems they form.

Mechanical interface having multiple grounded actuators

DOEpatents

Martin, Kenneth M.; Levin, Mike D.; Rosenberg, Louis B.

1998-01-01

An apparatus and method for interfacing the motion of a user-manipulable object with a computer system includes a user object physically contacted or grasped by a user. A 3-D spatial mechanism is coupled to the user object, such as a stylus or a medical instrument, and provides three degrees of freedom to the user object. Three grounded actuators provide forces in the three degrees of freedom. Two of the degrees of freedom are a planar workspace provided by a closed-loop linkage of members, and the third degree of freedom is rotation of the planar workspace provided by a rotatable carriage. Capstan drive mechanisms transmit forces between actuators and the user object and include drums coupled to the carriage, pulleys coupled to grounded actuators, and flexible cables transmitting force between the pulleys and the drums. The flexibility of the cable allows the drums to rotate with the carriage while the pulleys and actuators remain fixed to ground. The interface also may include a floating gimbal mechanism coupling the linkage to the user object. The floating gimbal mechanism includes rotatably coupled gimbal members that provide three degrees of freedom to the user object and capstan mechanisms coupled between sensors and the gimbal members for providing enhanced sensor resolution.

Proceedings of the Fifth Microgravity Fluid Physics and Transport Phenomena Conference

NASA Technical Reports Server (NTRS)

Singh, Bhim S. (Editor)

2000-01-01

The Fifth Microgravity Fluid Physics and Transport Phenomena Conference provided the scientific community the opportunity to view the current scope of the Microgravity Fluid Physics and Transport Phenomena Program and research opportunities and plans for the near future. Consistent with the conference theme "Microgravity Research an Agency-Wide Asset" the conference focused not only on fundamental research but also on applications of this knowledge towards enabling future space exploration missions. The conference included 14 invited plenary talks, 61 technical paper presentations, 61 poster presentations, exhibits and a forum on emerging research themes focusing on nanotechnology and biofluid mechanics. This web-based proceeding includes the presentation and poster charts provided by the presenters of technical papers and posters that were scanned at the conference site. Abstracts of all the papers and posters are included and linked to the presentations charts. The invited and plenary speakers were not required to provide their charts and are generally not available for scanning and hence not posted. The conference program is also included.

A comprehensive combustion model for biodiesel-fueled engine simulations

NASA Astrophysics Data System (ADS)

Brakora, Jessica L.

Engine models for alternative fuels are available, but few are comprehensive, well-validated models that include accurate physical property data as well as a detailed description of the fuel chemistry. In this work, a comprehensive biodiesel combustion model was created for use in multi-dimensional engine simulations, specifically the KIVA3v R2 code. The model incorporates realistic physical properties in a vaporization model developed for multi-component fuel sprays and applies an improved mechanism for biodiesel combustion chemistry. A reduced mechanism was generated from the methyl decanoate (MD) and methyl-9-decenoate (MD9D) mechanism developed at Lawrence Livermore National Laboratory. It was combined with a multi-component mechanism to include n-heptane in the fuel chemistry. The biodiesel chemistry was represented using a combination of MD, MD9D and n-heptane, which varied for a given fuel source. The reduced mechanism, which contained 63 species, accurately predicted ignition delay times of the detailed mechanism over a range of engine-specific operating conditions. Physical property data for the five methyl ester components of biodiesel were added to the KIVA library. Spray simulations were performed to ensure that the models adequately reproduce liquid penetration observed in biodiesel spray experiments. Fuel composition impacted liquid length as expected, with saturated species vaporizing more and penetrating less. Distillation curves were created to ensure the fuel vaporization process was comparable to available data. Engine validation was performed against a low-speed, high-load, conventional combustion experiments and the model was able to predict the performance and NOx formation seen in the experiment. High-speed, low-load, low-temperature combustion conditions were also modeled, and the emissions (HC, CO, NOx) and fuel consumption were well-predicted for a sweep of injection timings. Finally, comparisons were made between the results of biodiesel composition (palm vs. soy) and fuel blends (neat vs. B20). The model effectively reproduced the trends observed in the experiments.

A Sociocognitive Perspective of Women's Participation in Physics: Improving Accessibility throughout the Pipeline

NASA Astrophysics Data System (ADS)

Kelly, Angela

2017-01-01

Sociopsychological theories and empirical research provide a framework for exploring causal pathways and targeted interventions to increase the representation of women in post-secondary physics. Women earned only 19.7 percent of physics undergraduate degrees in 2012 (APS, 2015). This disparity has been attributed to a variety of factors, including chilly classroom climates, gender-based stereotypes, persistent self-doubt, and a lack of role models in physics departments. The theoretical framework for this research synthesis is based upon several psychological theories of sociocognitive behavior and is derived from three general constructs: 1) self-efficacy and self-concept; 2) expectancy value and planned behavior; and 3) motivation and self-determination. Recent studies have suggested that the gender discrepancy in physics participation may be alleviated by applying interventions derived from social cognitive research. These interventions include social and familial support, welcoming and collaborative classroom environments, critical feedback, and identification with a malleable view of intelligence. This research provides empirically supported mechanisms for university stakeholders to implement reforms that will increase women's participation in physics.

Physics of the inner heliosphere: Mechanisms, models and observational signatures

NASA Technical Reports Server (NTRS)

Withbroe, George L.

1987-01-01

Selected problems concerned with the important physical processes that occur in the corona and solar wind acceleration region, particularly time dependent phenomena were studied. Both the physics of the phenomena and the resultant effects on observational signatures, particularly spectroscopic signatures were also studied. Phenomena under study include: wave motions, particularly Alfven and fast mode waves; the formation of standing shocks in the inner heliosphere as a result of momentum and/or heat addition to the wind; and coronal transient phenomena where momentum and/or heat are deposited in the corona to produce transient plasma heating and/or mass ejection. The development of theoretical models for the inner heliosphere, the theoretical investigation of spectroscopic plasma diagnostics for this region, and the analysis of existing skylab and other relevant data are also included.

LASER Tech Briefs, September 1993. Volume 1, No. 1

NASA Technical Reports Server (NTRS)

Schnirring, Bill (Editor)

1993-01-01

This edition of LASER Tech briefs contains a feature on photonics. The other topics include: Electronic Components and Circuits. Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Fabrication Technology, Mathematics and Information Sciences, Life Sciences and books and reports.

NASA Tech Briefs, December 1995. Volume 19, No. 12

NASA Technical Reports Server (NTRS)

1995-01-01

Topics include: a special focus section on Bio/Medical technology, electronic components and circuits, electronic systems, physical sciences, materials, computer programs, mechanics, machinery, manufacturing/fabrication, mathematics and information sciences, book and reports, and a special section on Laser Tech Briefs.

Academic emergency physicians' experiences with patient death.

PubMed

Strote, Jared; Schroeder, Erika; Lemos, John; Paganelli, Ryan; Solberg, Jonathan; Range Hutson, H

2011-03-01

There is a growing awareness of the effects of patient death on physician well-being, and the importance of cultural and educational changes to improve coping mechanisms. The objective of this study was to explore both the effects of patient death on academic emergency physicians (EPs) and the coping mechanisms they use to deal with these events. Faculty at a convenience sample of four emergency medicine (EM) residency programs were questioned about their responses to patient death in a 15-question on-line survey. Descriptive analysis of the data was performed. Independent variables were analyzed for differences in complaints of physical symptoms or consideration of important life changes after patient death. Of 207 EPs surveyed, 145 (70%) responded. Patient death was experienced frequently, with 95 (66%) witnessing a death at least every month. No training on coping with patient death had occurred for 35 (24%); 93 (64%) had less than 6 hours of training. The most common coping mechanisms included talking with colleagues (113; 78%) or friends and family (100; 69%), as well as simply continuing to work (89; 61%). Postdeath debriefing occurred rarely or never for 93 (64%) of respondents. Most EPs had experienced physical responses to patient death, the most common being insomnia (54; 37%) and fatigue (21; 14%). Common emotional responses included sadness (112; 70%) and disappointment (55; 38%). No significant differences in response rates for physical symptoms or consideration of life changes were found for any of the variables. Patient death was reported to lead to both physical and emotional symptoms in academic EPs. Postdeath debriefing appears to happen infrequently in teaching settings, and most respondents reported that they themselves received limited training in coping with patient death. Further study is needed to both identify coping mechanisms that are feasible and effective in emergency department settings and develop teaching strategies to incorporate this information into EM residency training. © 2011 by the Society for Academic Emergency Medicine.

Aspects of the mechanisms of smoke generation by burning materials

NASA Technical Reports Server (NTRS)

Bankston, C. P.; Zinn, B. T.; Browner, R. F.; Powell, E. A.

1981-01-01

An investigation of smoke generation during the burning of natural and synthetic solid materials (relevant to fire safety problems), under simulated fire conditions, is presented. Smoke formation mechanisms, including flaming and nonflaming combustion, are reviewed, and the complex physical, chemical, and electrical processes, important in smoke particulate production, are identified. With reference to the smoke formation mechanisms, measured experimental data are discussed, and include effects of ventilation gas temperature, dependence on material composition, and chemical analysis of smoke particulates. Significant differences in smoke characteristics are observed between flaming and nonflaming conditions, which is attributed to specific differences in controlling mechanisms and resultant ways leading to particulate formation. The effects of polymer substrate properties and effects of additives for a given substrate on smoke properties are also discussed in terms of basic processes. It is shown that many of the measured trends can be interpreted by considering postulated mechanisms of particulate formation.

Yoichiro Nambu and the Mechanism of Spontaneous Broken Symmetries in

Science.gov Websites

Subatomic Physics RSS Archive Videos XML DOE R&D Accomplishments DOE R&D Mechanism of Spontaneous Broken Symmetries in Subatomic Physics Resources with Additional Information Physics "for the discovery of the mechanism of spontaneous broken symmetry in subatomic physics"

Coupling functions: Universal insights into dynamical interaction mechanisms

NASA Astrophysics Data System (ADS)

Stankovski, Tomislav; Pereira, Tiago; McClintock, Peter V. E.; Stefanovska, Aneta

2017-10-01

The dynamical systems found in nature are rarely isolated. Instead they interact and influence each other. The coupling functions that connect them contain detailed information about the functional mechanisms underlying the interactions and prescribe the physical rule specifying how an interaction occurs. A coherent and comprehensive review is presented encompassing the rapid progress made recently in the analysis, understanding, and applications of coupling functions. The basic concepts and characteristics of coupling functions are presented through demonstrative examples of different domains, revealing the mechanisms and emphasizing their multivariate nature. The theory of coupling functions is discussed through gradually increasing complexity from strong and weak interactions to globally coupled systems and networks. A variety of methods that have been developed for the detection and reconstruction of coupling functions from measured data is described. These methods are based on different statistical techniques for dynamical inference. Stemming from physics, such methods are being applied in diverse areas of science and technology, including chemistry, biology, physiology, neuroscience, social sciences, mechanics, and secure communications. This breadth of application illustrates the universality of coupling functions for studying the interaction mechanisms of coupled dynamical systems.

Counterfactual Definiteness and Bell's Inequality

NASA Astrophysics Data System (ADS)

Hess, Karl; Raedt, Hans De; Michielsen, Kristel

Counterfactual definiteness must be used as at least one of the postulates or axioms that are necessary to derive Bell-type inequalities. It is considered by many to be a postulate that is not only commensurate with classical physics (as for example Einstein's special relativity), but also separates and distinguishes classical physics from quantum mechanics. It is the purpose of this paper to show that Bell's choice of mathematical functions and independent variables implicitly includes counterfactual definiteness and reduces the generality of the physics of Bell-type theories so significantly that no meaningful comparison of these theories with actual Einstein-Podolsky-Rosen experiments can be made.

Tuning chemical and physical cross-links in silk electrogels for morphological analysis and mechanical reinforcement.

PubMed

Lin, Yinan; Xia, Xiaoxia; Shang, Ke; Elia, Roberto; Huang, Wenwen; Cebe, Peggy; Leisk, Gary; Omenetto, Fiorenzo; Kaplan, David L

2013-08-12

Electrochemically controlled, reversible assembly of biopolymers into hydrogel structures is a promising technique for on-demand cell or drug encapsulation and release systems. An electrochemically sol-gel transition has been demonstrated in regenerated Bombyx mori silk fibroin, offering a controllable way to generate biocompatible and reversible adhesives and other biomedical materials. Despite the involvement of an electrochemically triggered electrophoretic migration of the silk molecules, the mechanism of the reversible electrogelation remains unclear. It is, however, known that the freshly prepared silk electrogels (e-gels) adopt a predominantly random coil conformation, indicating a lack of cross-linking as well as thermal, mechanical, and morphological stabilities. In the present work, the tuning of covalent and physical β-sheet cross-links in silk hydrogels was studied for programming the structural properties. Scanning electron microscopy (SEM) revealed delicate morphology, including locally aligned fibrillar structures, in silk e-gels, preserved by combining glutaraldehyde-cross-linking and ethanol dehydration. Fourier transform infrared (FTIR) spectroscopic analysis of either electrogelled, vortex-induced or spontaneously formed silk hydrogels showed that the secondary structure of silk e-gels was tunable between non-β-sheet-dominated and β-sheet-dominated states. Dynamic oscillatory rheology confirmed the mechanical reinforcement of silk e-gels provided by controlled chemical and physical cross-links. The selective incorporation of either chemical or physical or both cross-links into the electrochemically responsive, originally unstructured silk e-gel should help in the design for electrochemically responsive protein polymers.

Physics of base-pairing dynamics in DNA

NASA Astrophysics Data System (ADS)

Manghi, Manoel; Destainville, Nicolas

2016-05-01

As a key molecule of life, Deoxyribo-Nucleic Acid (DNA) is the focus of numbers of investigations with the help of biological, chemical and physical techniques. From a physical point of view, both experimental and theoretical works have brought quantitative insights into DNA base-pairing dynamics that we review in this Report, putting emphasis on theoretical developments. We discuss the dynamics at the base-pair scale and its pivotal coupling with the polymer one, with a polymerization index running from a few nucleotides to tens of kilo-bases. This includes opening and closure of short hairpins and oligomers as well as zipping and unwinding of long macromolecules. We review how different physical mechanisms are either used by Nature or utilized in biotechnological processes to separate the two intertwined DNA strands, by insisting on quantitative results. They go from thermally-assisted denaturation bubble nucleation to force- or torque-driven mechanisms. We show that the helical character of the molecule, possibly supercoiled, can play a key role in many denaturation and renaturation processes. We categorize the mechanisms according to the relative timescales associated with base-pairing and chain orientational degrees of freedom such as bending and torsional elastic ones. In some specific situations, these chain orientational degrees of freedom can be integrated out, and the quasi-static approximation is valid. The complex dynamics then reduces to the diffusion in a low-dimensional free-energy landscape. In contrast, some important cases of experimental interest necessarily appeal to far-from-equilibrium statistical mechanics and hydrodynamics.

Extracting material response from simple mechanical tests on hardening-softening-hardening viscoplastic solids

NASA Astrophysics Data System (ADS)

Mohan, Nisha

Compliant foams are usually characterized by a wide range of desirable mechanical properties. These properties include viscoelasticity at different temperatures, energy absorption, recoverability under cyclic loading, impact resistance, and thermal, electrical, acoustic and radiation-resistance. Some foams contain nano-sized features and are used in small-scale devices. This implies that the characteristic dimensions of foams span multiple length scales, rendering modeling their mechanical properties difficult. Continuum mechanics-based models capture some salient experimental features like the linear elastic regime, followed by non-linear plateau stress regime. However, they lack mesostructural physical details. This makes them incapable of accurately predicting local peaks in stress and strain distributions, which significantly affect the deformation paths. Atomistic methods are capable of capturing the physical origins of deformation at smaller scales, but suffer from impractical computational intensity. Capturing deformation at the so-called meso-scale, which is capable of describing the phenomenon at a continuum level, but with some physical insights, requires developing new theoretical approaches. A fundamental question that motivates the modeling of foams is `how to extract the intrinsic material response from simple mechanical test data, such as stress vs. strain response?' A 3D model was developed to simulate the mechanical response of foam-type materials. The novelty of this model includes unique features such as the hardening-softening-hardening material response, strain rate-dependence, and plastically compressible solids with plastic non-normality. Suggestive links from atomistic simulations of foams were borrowed to formulate a physically informed hardening material input function. Motivated by a model that qualitatively captured the response of foam-type vertically aligned carbon nanotube (VACNT) pillars under uniaxial compression [2011,"Analysis of Uniaxial Compression of Vertically Aligned Carbon Nanotubes," J. Mech.Phys. Solids, 59, pp. 2227--2237, Erratum 60, 1753-1756 (2012)], the property space exploration was advanced to three types of simple mechanical tests: 1) uniaxial compression, 2) uniaxial tension, and 3) nanoindentation with a conical and a flat-punch tip. The simulations attempt to explain some of the salient features in experimental data, like 1) The initial linear elastic response. 2) One or more nonlinear instabilities, yielding, and hardening. The model-inherent relationships between the material properties and the overall stress-strain behavior were validated against the available experimental data. The material properties include the gradient in stiffness along the height, plastic and elastic compressibility, and hardening. Each of these tests was evaluated in terms of their efficiency in extracting material properties. The uniaxial simulation results proved to be a combination of structural and material influences. Out of all deformation paths, flat-punch indentation proved to be superior since it is the most sensitive in capturing the material properties.

The principle of finiteness - a guideline for physical laws

NASA Astrophysics Data System (ADS)

Sternlieb, Abraham

2013-04-01

I propose a new principle in physics-the principle of finiteness (FP). It stems from the definition of physics as a science that deals with measurable dimensional physical quantities. Since measurement results including their errors, are always finite, FP postulates that the mathematical formulation of legitimate laws in physics should prevent exactly zero or infinite solutions. I propose finiteness as a postulate, as opposed to a statement whose validity has to be corroborated by, or derived theoretically or experimentally from other facts, theories or principles. Some consequences of FP are discussed, first in general, and then more specifically in the fields of special relativity, quantum mechanics, and quantum gravity. The corrected Lorentz transformations include an additional translation term depending on the minimum length epsilon. The relativistic gamma is replaced by a corrected gamma, that is finite for v=c. To comply with FP, physical laws should include the relevant extremum finite values in their mathematical formulation. An important prediction of FP is that there is a maximum attainable relativistic mass/energy which is the same for all subatomic particles, meaning that there is a maximum theoretical value for cosmic rays energy. The Generalized Uncertainty Principle required by Quantum Gravity is actually a necessary consequence of FP at Planck's scale. Therefore, FP may possibly contribute to the axiomatic foundation of Quantum Gravity.

Particle astrophysics

NASA Technical Reports Server (NTRS)

Sadoulet, Bernard; Cronin, James; Aprile, Elena; Barish, Barry C.; Beier, Eugene W.; Brandenberger, Robert; Cabrera, Blas; Caldwell, David; Cassiday, George; Cline, David B.

1991-01-01

The following scientific areas are reviewed: (1) cosmology and particle physics (particle physics and the early universe, dark matter, and other relics); (2) stellar physics and particles (solar neutrinos, supernovae, and unconventional particle physics); (3) high energy gamma ray and neutrino astronomy; (4) cosmic rays (space and ground observations). Highest scientific priorities for the next decade include implementation of the current program, new initiatives, and longer-term programs. Essential technological developments, such as cryogenic detectors of particles, new solar neutrino techniques, and new extensive air shower detectors, are discussed. Also a certain number of institutional issues (the funding of particle astrophysics, recommended funding mechanisms, recommended facilities, international collaborations, and education and technology) which will become critical in the coming decade are presented.

Solar Physics - Plasma Physics Workshop

NASA Technical Reports Server (NTRS)

Baum, P. J.; Beckers, J. M.; Newman, C. E.; Priest, E. R.; Rosenberg, H.; Smith, D. F.; Sturrock, P. A.; Wentzel, D. G.

1974-01-01

A summary of the proceedings of a conference whose purpose was to explore plasma physics problems which arise in the study of solar physics is provided. Sessions were concerned with specific questions including the following: (1) whether the solar plasma is thermal or non-themal; (2) what spectroscopic data is required; (3) what types of magnetic field structures exist; (4) whether magnetohydrodynamic instabilities occur; (5) whether resistive or non-magnetohydrodynamic instabilities occur; (6) what mechanisms of particle acceleration have been proposed; and (7) what information is available concerning shock waves. Very few questions were answered categorically but, for each question, there was discussion concerning the observational evidence, theoretical analyses, and existing or potential laboratory and numerical experiments.

Physics at the FQMT'11 conference

NASA Astrophysics Data System (ADS)

Špička, V.; Nieuwenhuizen, Th M.; Keefe, P. D.

2012-11-01

This paper deals with the recent state of the art of the following topics presented at the FQMT'11 conference: foundations of quantum physics, quantum measurement; nonequilibrium quantum statistical physics; quantum thermodynamics; quantum measurement, entanglement and coherence; dissipation, dephasing, noise, and decoherence; quantum optics; macroscopic quantum behavior; e.g. cold atoms; Bose-Einstein condensates; physics of quantum computing and quantum information; mesoscopic, nano-electro-mechanical systems and nano-optical systems; spin systems and their dynamics; biological systems and molecular motors; and cosmology, gravitation and astrophysics. The lectures and discussions at the FQMT'11 conference, as well as the contributions to the related topical issue, reveal important themes for future development. The recent literature is included.

Investigation of the behavior of VOCs in ground water across fine- and coarse-grained geological contacts using a medium-scale physical model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoffman, F.; Chiarappa, M.L.

1998-03-01

One of the serious impediments to the remediation of ground water contaminated with volatile organic compounds (VOCs) is that the VOCs are retarded with respect to the movement of the ground water. Although the processes that result in VOC retardation are poorly understood, we have developed a conceptual model that includes several retarding mechanisms. These include adsorption to inorganic surfaces, absorption to organic carbon, and diffusion into areas of immobile waters. This project was designed to evaluate the relative contributions of these mechanisms; by improving our understanding, we hope to inspire new remediation technologies or approaches. Our project consisted ofmore » a series of column experiments designed to measure the retardation, in different geological media, of four common ground water VOCs (chloroform, carbon tetrachloride, trichloroethylene, and tetrachloroethylene) which have differing physical and chemical characteristics. It also included a series of diffusion parameters that constrain the model, we compared the data from these experiments to the output of a computational model.« less

Three-dimensional plotter technology for fabricating polymeric scaffolds with micro-grooved surfaces.

PubMed

Son, JoonGon; Kim, GeunHyung

2009-01-01

Various mechanical techniques have been used to fabricate biomedical scaffolds, including rapid prototyping (RP) devices that operate from CAD files of the target feature information. The three-dimensional (3-D) bio-plotter is one RP system that can produce design-based scaffolds with good mechanical properties for mimicking cartilage and bones. However, the scaffolds fabricated by RP have very smooth surfaces, which tend to discourage initial cell attachment. Initial cell attachment, migration, differentiation and proliferation are strongly dependent on the chemical and physical characteristics of the scaffold surface. In this study, we propose a new 3-D plotting method supplemented with a piezoelectric system for fabricating surface-modified scaffolds. The effects of the physically-modified surface on the mechanical and hydrophilic properties were investigated, and the results of cell culturing of chondrocytes indicate that this technique is a feasible new method for fabricating high-quality 3-D polymeric scaffolds.

Role of exercise in maintaining the integrity of the neuromuscular junction

PubMed Central

Nishimune, Hiroshi; Stanford, John A.; Mori, Yasuo

2014-01-01

Physical activity plays an important role in preventing chronic disease in adults and the elderly. Exercise has beneficial effects on the nervous system, including at the neuromuscular junction (NMJ). Exercise causes hypertrophy of NMJs and improves recovery from peripheral nerve injuries, whereas decreased physical activity causes degenerative changes in NMJs. Recent studies have begun to elucidate molecular mechanisms underlying the beneficial effects of exercise. These mechanisms involve Bassoon, neuregulin-1, peroxisome proliferator-activated receptor gamma coactivator 1α, Insulin-like growth factor-1, glial cell line-derived neurotrophic factor, neurotrophin 4, Homer, and nuclear factor of activated T cells c1. For example, NMJ denervation and active zone decreases have been observed in aged NMJs, but these age-dependent degenerative changes can be ameliorated by exercise. This review will discuss the effects of exercise on the maintenance and regeneration of NMJs and will highlight recent insights into the molecular mechanisms underlying these exercise effects. PMID:24122772

Mechanically Activated Ion Channels

PubMed Central

Ranade, Sanjeev S.; Syeda, Ruhma; Patapoutian, Ardem

2015-01-01

Mechanotransduction, the conversion of physical forces into biochemical signals, is an essential component of numerous physiological processes including not only conscious senses of touch and hearing, but also unconscious senses such as blood pressure regulation. Mechanically activated (MA) ion channels have been proposed as sensors of physical force, but the identity of these channels and an understanding of how mechanical force is transduced has remained elusive. A number of recent studies on previously known ion channels along with the identification of novel MA ion channels have greatly transformed our understanding of touch and hearing in both vertebrates and invertebrates. Here, we present an updated review of eukaryotic ion channel families that have been implicated in mechanotransduction processes and evaluate the qualifications of the candidate genes according to specified criteria. We then discuss the proposed gating models for MA ion channels and highlight recent structural studies of mechanosensitive potassium channels. PMID:26402601

Preoperative physical therapy for elective cardiac surgery patients.

PubMed

Hulzebos, Erik H J; Smit, Yolba; Helders, Paul P J M; van Meeteren, Nico L U

2012-11-14

After cardiac surgery, physical therapy is a routine procedure delivered with the aim of preventing postoperative pulmonary complications. To determine if preoperative physical therapy with an exercise component can prevent postoperative pulmonary complications in cardiac surgery patients, and to evaluate which type of patient benefits and which type of physical therapy is most effective. Searches were run on the Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library (2011, Issue 12 ); MEDLINE (1966 to 12 December 2011); EMBASE (1980 to week 49, 2011); the Physical Therapy Evidence Database (PEDro) (to 12 December 2011) and CINAHL (1982 to 12 December 2011). Randomised controlled trials or quasi-randomised trials comparing preoperative physical therapy with no preoperative physical therapy or sham therapy in adult patients undergoing elective cardiac surgery. Data were collected on the type of study, participants, treatments used, primary outcomes (postoperative pulmonary complications grade 2 to 4: atelectasis, pneumonia, pneumothorax, mechanical ventilation > 48 hours, all-cause death, adverse events) and secondary outcomes (length of hospital stay, physical function measures, health-related quality of life, respiratory death, costs). Data were extracted by one review author and checked by a second review author. Review Manager 5.1 software was used for the analysis. Eight randomised controlled trials with 856 patients were included. Three studies used a mixed intervention (including either aerobic exercises or breathing exercises); five studies used inspiratory muscle training. Only one study used sham training in the controls. Patients that received preoperative physical therapy had a reduced risk of postoperative atelectasis (four studies including 379 participants, relative risk (RR) 0.52; 95% CI 0.32 to 0.87; P = 0.01) and pneumonia (five studies including 448 participants, RR 0.45; 95% CI 0.24 to 0.83; P = 0.01) but not of pneumothorax (one study with 45 participants, RR 0.12; 95% CI 0.01 to 2.11; P = 0.15) or mechanical ventilation for > 48 hours after surgery (two studies with 306 participants, RR 0.55; 95% CI 0.03 to 9.20; P = 0.68). Postoperative death from all causes did not differ between groups (three studies with 552 participants, RR 0.66; 95% CI 0.02 to 18.48; P = 0.81). Adverse events were not detected in the three studies that reported on them. The length of postoperative hospital stay was significantly shorter in experimental patients versus controls (three studies with 347 participants, mean difference -3.21 days; 95% CI -5.73 to -0.69; P = 0.01). One study reported a reduced physical function measure on the six-minute walking test in experimental patients compared to controls. One other study reported a better health-related quality of life in experimental patients compared to controls. Postoperative death from respiratory causes did not differ between groups (one study with 276 participants, RR 0.14; 95% CI 0.01 to 2.70; P = 0.19). Cost data were not reported on. Evidence derived from small trials suggests that preoperative physical therapy reduces postoperative pulmonary complications (atelectasis and pneumonia) and length of hospital stay in patients undergoing elective cardiac surgery. There is a lack of evidence that preoperative physical therapy reduces postoperative pneumothorax, prolonged mechanical ventilation or all-cause deaths.

NASA Tech Briefs, March 1998. Volume 22, No. 3

NASA Technical Reports Server (NTRS)

1998-01-01

Topics include: special coverage of computer aided design and engineering, electronic components and circuits, electronic systems, physical sciences, materials, computer software, special coverage on mechanical technology, machinery/automation, manufacturing/fabrication, mathematics and information sciences, book and reports, and a special section of Electronics Tech Briefs. Profiles of the exhibitors at the National Design Engineering show are also included in this issue.

NASA Tech Briefs, Summer 1976. Volume 1, No. 2

NASA Technical Reports Server (NTRS)

1976-01-01

Topics covered include: Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Life Sciences; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences. Also included are; NASA TU Services: Technology Utilization services that can assist you in learning about and applying NASA technology; and New Product Ideas: A summary of selected innovations of value to manufacturers for the development of new products.

Let's Get Physical: Teaching Physics Through Gymnastics

NASA Astrophysics Data System (ADS)

Sojourner, Elena J.; Burgasser, Adam J.; Weise, Eric D.

2018-01-01

The concept of embodied learning—that we can learn with our bodies and with our minds—is a well-established concept in physics and math education research, and includes symbolic understanding (e.g., gestures that track how students think or facilitate learning to model complex systems of energy flow) as well as the literal experience of exploring physical phenomena through body movements. Sport has long served as a guide for both illustrating and experiencing physical concepts and phenomena, with a particularly relevant example being the sport of gymnastics. Here, the practitioner is subjected to a wide range of forces and torques, and experiences translational and rotational motions, all guided by control of body positioning, shape, strength, and leverage. Smith provides a comprehensive study of the mechanics used to analyze gymnastic movements, which includes core concepts such as force balance, leverage and torque, center of mass and stability, moment of inertia, ballistic motion, pendulum motion, and circular motion. For life science majors, gymnastics also provides relevant physical examples of biomechanics and the physical limits of biological materials (skin, bones, ligaments). The popularity of gymnastics—consider the phenomenon of Simone Biles—makes it broadly accessible and engaging, particularly across genders.

Causal-explanatory pluralism: How intentions, functions, and mechanisms influence causal ascriptions.

PubMed

Lombrozo, Tania

2010-12-01

Both philosophers and psychologists have argued for the existence of distinct kinds of explanations, including teleological explanations that cite functions or goals, and mechanistic explanations that cite causal mechanisms. Theories of causation, in contrast, have generally been unitary, with dominant theories focusing either on counterfactual dependence or on physical connections. This paper argues that both approaches to causation are psychologically real, with different modes of explanation promoting judgments more or less consistent with each approach. Two sets of experiments isolate the contributions of counterfactual dependence and physical connections in causal ascriptions involving events with people, artifacts, or biological traits, and manipulate whether the events are construed teleologically or mechanistically. The findings suggest that when events are construed teleologically, causal ascriptions are sensitive to counterfactual dependence and relatively insensitive to the presence of physical connections, but when events are construed mechanistically, causal ascriptions are sensitive to both counterfactual dependence and physical connections. The conclusion introduces an account of causation, an "exportable dependence theory," that provides a way to understand the contributions of physical connections and teleology in terms of the functions of causal ascriptions. Copyright © 2010 Elsevier Inc. All rights reserved.

Use of clickers and sustainable reform in upper-division physics courses

NASA Astrophysics Data System (ADS)

Dubson, Michael

2008-03-01

At the University of Colorado at Boulder, successful reforms of our freshmen and sophomore-level physics courses are now being extended to upper-division courses, including Mechanics, Math Methods, QM, E&M, and Thermal Physics. Our course reforms include clicker questions (ConcepTests) in lecture, peer instruction, and an added emphasis on conceptual understanding and qualitative reasoning on homework assignments and exams. Student feedback has been strongly positive, and I will argue that such conceptual training improves rather than dilutes, traditional, computationally-intensive problem-solving skills. In order for these reforms to be sustainable, reform efforts must begin with department-wide consensus and agreed-upon measures of success. I will discuss the design of good clicker questions and effective incorporation into upper-level courses, including examples from materials science. Condensed matter physics, which by nature involve intelligent use of approximation, particularly lends itself to conceptual training. I will demonstrate the use of a clicker system (made by iClicker) with audience-participation questions. Come prepared to think and interact, rather than just sit there!

Physical Processes and Applications of the Monte Carlo Radiative Energy Deposition (MRED) Code

NASA Astrophysics Data System (ADS)

Reed, Robert A.; Weller, Robert A.; Mendenhall, Marcus H.; Fleetwood, Daniel M.; Warren, Kevin M.; Sierawski, Brian D.; King, Michael P.; Schrimpf, Ronald D.; Auden, Elizabeth C.

2015-08-01

MRED is a Python-language scriptable computer application that simulates radiation transport. It is the computational engine for the on-line tool CRÈME-MC. MRED is based on c++ code from Geant4 with additional Fortran components to simulate electron transport and nuclear reactions with high precision. We provide a detailed description of the structure of MRED and the implementation of the simulation of physical processes used to simulate radiation effects in electronic devices and circuits. Extensive discussion and references are provided that illustrate the validation of models used to implement specific simulations of relevant physical processes. Several applications of MRED are summarized that demonstrate its ability to predict and describe basic physical phenomena associated with irradiation of electronic circuits and devices. These include effects from single particle radiation (including both direct ionization and indirect ionization effects), dose enhancement effects, and displacement damage effects. MRED simulations have also helped to identify new single event upset mechanisms not previously observed by experiment, but since confirmed, including upsets due to muons and energetic electrons.

[Age-related dynamics of the maximum oxygen consumption associated with different regimens of locomotor activity].

PubMed

Miakotnykh, V V; Khodasevich, L S; Ermakov, B A

2011-01-01

This study included a total of 234 practically healthy men at the age from 40 to 69 years differing in the regimen of daily locomotor activity. They were divided into 4 groups, each comprised of subjects ranged by age with a ten-year interval. Group 1 included former high-level athletes continuing active physical training, group 2 was comprised of former high-level athletes living a sedentary life style, group 3 consisted of subjects regularly engaged in health-giving physical exercises, and group 4 included subjects who were never engaged in physical exercises. The energy consumption by the members of all four groups was estimated when they were undergoing a stepwise increasing workload on the veloergometer measured with the help of a computerized diagnostic system. The results of the study indicate that the high oxygen consumption at a limiting load in the former high-level athletes is associated with the significant economization of basal metabolism and the reduction of oxygen consumption at rest. This mechanism accounts for the possibility to retain adequate physical activity of the organism up to the age of 70 years.

40 CFR 141.100 - Criteria and procedures for public water systems using point-of-entry devices.

Code of Federal Regulations, 2011 CFR

2011-07-01

... include physical measurements and observations such as total flow treated and mechanical condition of the... engineering design review of the point-of-entry devices. (2) The design and application of the point-of-entry...

40 CFR 141.100 - Criteria and procedures for public water systems using point-of-entry devices.

Code of Federal Regulations, 2013 CFR

2013-07-01

... include physical measurements and observations such as total flow treated and mechanical condition of the... engineering design review of the point-of-entry devices. (2) The design and application of the point-of-entry...

40 CFR 141.100 - Criteria and procedures for public water systems using point-of-entry devices.

Code of Federal Regulations, 2012 CFR

2012-07-01

... include physical measurements and observations such as total flow treated and mechanical condition of the... engineering design review of the point-of-entry devices. (2) The design and application of the point-of-entry...

NASA Tech Briefs, October 1998. Volume 22, No. 10

NASA Technical Reports Server (NTRS)

1998-01-01

Topics include: special coverage sections on sensors/imaging and mechanical technology, and sections on electronic components and circuits, electronic systems, software, materials, machinery/automation, manufacturing/fabrication, physical sciences, information sciences, book and reports, and a special section of Photonics Tech Briefs.

NASA Tech Briefs, April 1989. Volume 13, No. 4

NASA Technical Reports Server (NTRS)

1989-01-01

A special feature of this issue is an article about the evolution of high technology in Texas. Topics include: Electronic Components & and Circuits. Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Fabrication Technology, Mathematics and Information Sciences, and Life Sciences.

NASA Tech Briefs, May 1989. Volume 13, No. 5

NASA Technical Reports Server (NTRS)

1989-01-01

This issue contains a special feature on the flight station of the future, discussing future enhancements to Aircraft cockpits. Topics include: Electronic Components and Circuits. Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Fabrication Technology, and Mathematics and Information Sciences.

What Influences Patient-Therapist Interactions in Musculoskeletal Physical Therapy? Qualitative Systematic Review and Meta-Synthesis.

PubMed

O'Keeffe, Mary; Cullinane, Paul; Hurley, John; Leahy, Irene; Bunzli, Samantha; O'Sullivan, Peter B; O'Sullivan, Kieran

2016-05-01

Musculoskeletal physical therapy involves both specific and nonspecific effects. Nonspecific variables associated with the patient, therapist, and setting may influence clinical outcomes. Recent quantitative research has shown that nonspecific factors, including patient-therapist interactions, can influence treatment outcomes. It remains unclear, however, what factors influence patient-therapist interaction. This qualitative systematic review and meta-synthesis investigated patients' and physical therapists' perceptions of factors that influence patient-therapist interactions. Eleven databases were searched independently. Qualitative studies examining physical therapists' and patients' perceptions of factors that influence patient-therapist interactions in musculoskeletal settings were included. Two reviewers independently selected articles, assessed methodological quality using the Critical Appraisal Skills Programme (CASP), and performed the 3 stages of analysis: extraction of findings, grouping of findings (codes), and abstraction of findings. Thirteen studies were included. Four themes were perceived to influence patient-therapist interactions: (1) physical therapist interpersonal and communication skills (ie, presence of skills such as listening, encouragement, confidence, being empathetic and friendly, and nonverbal communication), (2) physical therapist practical skills (ie, physical therapist expertise and level of training, although the ability to provide good education was considered as important only by patients), (3) individualized patient-centered care (ie, individualizing the treatment to the patient and taking patient's opinions into account), and (4) organizational and environmental factors (ie, time and flexibility with care and appointments). Only studies published in English were included. A mix of interpersonal, clinical, and organizational factors are perceived to influence patient-therapist interactions, although research is needed to identify which of these factors actually influence patient-therapist interactions. Physical therapists' awareness of these factors could enhance patient interactions and treatment outcomes. Mechanisms to best enhance these factors in clinical practice warrant further study. © 2016 American Physical Therapy Association.

The shear instability energy: a new parameter for materials design?

NASA Astrophysics Data System (ADS)

Kanani, M.; Hartmaier, A.; Janisch, R.

2017-10-01

Reliable and predictive relationships between fundamental microstructural material properties and observable macroscopic mechanical behaviour are needed for the successful design of new materials. In this study we establish a link between physical properties that are defined on the atomic level and the deformation mechanisms of slip planes and interfaces that govern the mechanical behaviour of a metallic material. To accomplish this, the shear instability energy Γ is introduced, which can be determined via quantum mechanical ab initio calculations or other atomistic methods. The concept is based on a multilayer generalised stacking fault energy calculation and can be applied to distinguish the different shear deformation mechanisms occurring at TiAl interfaces during finite-temperature molecular dynamics simulations. We use the new parameter Γ to construct a deformation mechanism map for different interfaces occurring in this intermetallic. Furthermore, Γ can be used to convert the results of ab initio density functional theory calculations into those obtained with an embedded atom method type potential for TiAl. We propose to include this new physical parameter into material databases to apply it for the design of materials and microstructures, which so far mainly relies on single-crystal values for the unstable and stable stacking fault energy.

Using Community Insight to Understand Physical Activity Adoption in Overweight and Obese African American and Hispanic Women: A Qualitative Study

PubMed Central

Mama, Scherezade K.; McCurdy, Sheryl A.; Evans, Alexandra E.; Thompson, Deborah I.; Diamond, Pamela M.; Lee, Rebecca E.

2015-01-01

Ecologic models suggest that multiple levels of influencing factors are important for determining physical activity participation and include individual, social, and environmental factors. The purpose of this qualitative study was to use an ecologic framework to gain a deeper understanding of the underlying behavioral mechanisms that influence physical activity adoption among ethnic minority women. Eighteen African American and Hispanic women completed a 1-hour in-depth interview. Verbatim interview transcripts were analyzed for emergent themes using a constant comparison approach. Women were middle-aged (age M = 43.9 ± 7.3 years), obese (body mass index M = 35.0 ± 8.9 kg/m2), and of high socioeconomic status (88.9% completed some college or more, 41.2% reported income >$82,600/year). Participants discussed individual factors, including the need for confidence, motivation and time, and emphasized the importance of environmental factors, including their physical neighborhood environments and safety of and accessibility to physical activity resources. Women talked about caretaking for others and social support and how these influenced physical activity behavior. The findings from this study highlight the multilevel, interactive complexities that influence physical activity, emphasizing the need for a more sophisticated, ecologic approach for increasing physical activity adoption and maintenance among ethnic minority women. Community insight gleaned from this study may be used to better understand determinants of physical activity and develop multilevel solutions and programs guided by an ecologic framework to increase physical activity in ethnic minority women. PMID:25504569

Using community insight to understand physical activity adoption in overweight and obese African American and Hispanic women: a qualitative study.

PubMed

Mama, Scherezade K; McCurdy, Sheryl A; Evans, Alexandra E; Thompson, Deborah I; Diamond, Pamela M; Lee, Rebecca E

2015-06-01

Ecologic models suggest that multiple levels of influencing factors are important for determining physical activity participation and include individual, social, and environmental factors. The purpose of this qualitative study was to use an ecologic framework to gain a deeper understanding of the underlying behavioral mechanisms that influence physical activity adoption among ethnic minority women. Eighteen African American and Hispanic women completed a 1-hour in-depth interview. Verbatim interview transcripts were analyzed for emergent themes using a constant comparison approach. Women were middle-aged (age M = 43.9 ± 7.3 years), obese (body mass index M = 35.0 ± 8.9 kg/m(2)), and of high socioeconomic status (88.9% completed some college or more, 41.2% reported income >$82,600/year). Participants discussed individual factors, including the need for confidence, motivation and time, and emphasized the importance of environmental factors, including their physical neighborhood environments and safety of and accessibility to physical activity resources. Women talked about caretaking for others and social support and how these influenced physical activity behavior. The findings from this study highlight the multilevel, interactive complexities that influence physical activity, emphasizing the need for a more sophisticated, ecologic approach for increasing physical activity adoption and maintenance among ethnic minority women. Community insight gleaned from this study may be used to better understand determinants of physical activity and develop multilevel solutions and programs guided by an ecologic framework to increase physical activity in ethnic minority women. © 2014 Society for Public Health Education.

Electromagnetic backscattering by corner reflectors

NASA Technical Reports Server (NTRS)

Balanis, C. A.; Griesser, T.

1986-01-01

The Geometrical Theory of Diffraction (GTD), which supplements Geometric Optics (GO), and the Physical Theory of Diffraction (PTD), which supplements Physical Optics (PO), are used to predict the backscatter cross sections of dihedral corner reflectors which have right, obtuse, or acute included angles. These theories allow individual backscattering mechanisms of the dihedral corner reflectors to be identified and provide good agreement with experimental results in the azimuthal plane. The advantages and disadvantages of the geometrical and physical theories are discussed in terms of their accuracy, usefulness, and complexity. Numerous comparisons of analytical results with experimental data are presented. While physical optics alone is more accurate and more useful than geometrical optics alone, the combination of geometrical optics and geometrical diffraction seems to out perform physical optics and physical diffraction when compared with experimental data, especially for acute angle dihedral corner reflectors.

MAUVE: A New Strategy for Solving and Grading Physics Problems

NASA Astrophysics Data System (ADS)

Hill, Nicole Breanne

2016-05-01

MAUVE (magnitude, answer, units, variables, and equations) is a framework and rubric to help students and teachers through the process of clearly solving and assessing solutions to introductory physics problems. Success in introductory physics often derives from an understanding of units, a command over dimensional analysis, and good bookkeeping. I developed MAUVE for an introductory-level environmental physics course as an easy-to-remember checklist to help students construct organized and thoughtful solutions to physics problems. Environmental physics is a core physics course for environmental and sustainability science (ESS) majors that teaches principles of radiation, thermodynamics, and mechanics within the context of the environment and sustainable energy systems. ESS student concentrations include environmental biology, applied ecology, biogeochemistry, and natural resources. The MAUVE rubric, inspired by nature, has encouraged my students to produce legible and tactical work, and has significantly clarified the grading process.

Hitherto unknown shear rupture mechanism as a source of instability in intact hard rocks at highly confined compression

NASA Astrophysics Data System (ADS)

Tarasov, Boris G.

2014-05-01

Today, frictional shear resistance along pre-existing faults is considered to be the lower limit on rock shear strength for confined conditions corresponding to the seismogenic layer. This paper introduces a recently identified shear rupture mechanism providing a paradoxical feature of hard rocks - the possibility of shear rupture propagation through the highly confined intact rock mass at shear stress levels significantly less than frictional strength. In the new mechanism, the rock failure associated with consecutive creation of small slabs (known as ‘domino-blocks') from the intact rock in the rupture tip is driven by a fan-shaped domino structure representing the rupture head. The fan-head combines such unique features as: extremely low shear resistance, self-sustaining stress intensification, and self-unbalancing conditions. Due to this the failure process caused by the mechanism is very dynamic and violent. This makes it impossible to directly observe and study the mechanism and can explain why the mechanism has not been detected before. This paper provides physical motivation for the mechanism, based upon side effects accompanying the failure process. Physical and mathematical models of the mechanism presented in the paper explain unique and paradoxical features of the mechanism. The new shear rupture mechanism allows a novel point of view for understanding the nature of spontaneous failure processes in hard rocks including earthquakes.

Multi-Physics MRI-Based Two-Layer Fluid-Structure Interaction Anisotropic Models of Human Right and Left Ventricles with Different Patch Materials: Cardiac Function Assessment and Mechanical Stress Analysis

PubMed Central

Tang, Dalin; Yang, Chun; Geva, Tal; Gaudette, Glenn; del Nido, Pedro J.

2011-01-01

Multi-physics right and left ventricle (RV/LV) fluid-structure interaction (FSI) models were introduced to perform mechanical stress analysis and evaluate the effect of patch materials on RV function. The FSI models included three different patch materials (Dacron scaffold, treated pericardium, and contracting myocardium), two-layer construction, fiber orientation, and active anisotropic material properties. The models were constructed based on cardiac magnetic resonance (CMR) images acquired from a patient with severe RV dilatation and solved by ADINA. Our results indicate that the patch model with contracting myocardium leads to decreased stress level in the patch area, improved RV function and patch area contractility. PMID:21765559

Principles of physics in surgery: the laws of mechanics and vectors physics for surgeons-part 2.

PubMed

Srivastava, Anurag; Sood, Akshay; Joy, Parijat S; Mandal, Shubhyan; Panwar, Rajesh; Ravichandran, Suresh; Sarangi, Sasmit; Woodcock, John

2010-10-01

In this sequel, to an earlier article, we discuss the laws of Mechanics, Thermodynamics and Vectors as they apply to soft and bony tissues. These include the Laplace's Law as applied to colonic perforation, compression therapy, parturition, variceal rupture, disc herniations etc. The Pascal's Law finds use in hernia repair and the Heimlich maneuver. Trigonometrically derived components of forces, acting after suturing, show ways to reduce cut-through; the thickness and the bite of suture determines the extent of tissue reaction. The heating effect of current explains the optimum gap between the prongs of a bipolar cautery and the use of law of transfer of heat in determining relation between healthy wound healing and ambient temperature.

Method and apparatus for determination of mechanical properties of functionally-graded materials

DOEpatents

Giannakopoulos, Antonios E.; Suresh, Subra

1999-01-01

Techniques for the determination of mechanical properties of homogenous or functionally-graded materials from indentation testing are presented. The technique is applicable to indentation on the nano-scale through the macro-scale including the geological scale. The technique involves creating a predictive load/depth relationship for a sample, providing an experimental load/depth relationship, comparing the experimental data to the predictive data, and determining a physical characteristic from the comparison.

Visualization of the Invisible: The Qubit as Key to Quantum Physics

NASA Astrophysics Data System (ADS)

Dür, Wolfgang; Heusler, Stefan

2014-11-01

Quantum mechanics is one of the pillars of modern physics, however rather difficult to teach at the introductory level due to the conceptual difficulties and the required advanced mathematics. Nevertheless, attempts to identify relevant features of quantum mechanics and to put forward concepts of how to teach it have been proposed.1-8 Here we present an approach to quantum physics based on the simplest quantum mechanical system—the quantum bit (qubit).1 Like its classical counterpart—the bit—a qubit corresponds to a two-level system, i.e., some system with a physical property that can admit two possible values. While typically a physical system has more than just one property or the property can admit more than just two values, in many situations most degrees of freedom can be considered to be fixed or frozen. Hence a variety of systems can be effectively described as a qubit. For instance, one may consider the spin of an electron or atom, with spin up and spin down as two possible values, and where other properties of the particle such as its mass or its position are fixed. Further examples include the polarization degree of freedom of a photon (horizontal and vertical polarization), two electronic degrees of freedom (i.e., two energy levels) of an atom, or the position of an atom in a double well potential (atom in left or right well). In all cases, only two states are relevant to describe the system.

The Entrance test of physics and Workbook in teaching of physics at secondary vocational school within long-term pedagogical research

NASA Astrophysics Data System (ADS)

Kerlínová, Věra

2017-01-01

Within the long-term pedagogical research ongoing since the school year 2008/2009 to 2015/2016 at the secondary vocational school in Bohumín was through of Entrance test of physics, which included curriculum of the sixth to ninth year of elementary school, regularly finding out, in which parts of Entrance test - Unit conversions, International System of Units, Properties of matter, Mechanics, Thermodynamics, Electricity and Magnetism, Optics, Atoms and Universe - pupils of the 1st years of secondary vocational school, technical and non-technical, reach a higher number of correct answers, in which dominates the wrong answers and which parts of the test pupils are better left out completely. It turned out that the results of these tests are very informative not only for theoretical and practical teaching, but also technical and other science subjects. The results of the Entrance tests are also a valuable source of information for continuous innovation Workbook of Physics - Mechanics for the 1st year of secondary vocational schools [1] - whose the first version began during the school year 2007/2008 and which was tested within pre-research in school years 2008/2009, 2009/2010 and within research in school year 2010/2011. On the basis of feedbacks getting from research the Workbook is regularly expanded, innovated and updated. The Workbook consists of parts dedicated to physical concepts, physical tasks, proposals to physical experiments, pupils comments from viewed video projection and documentary films, examples from the world of science and technology, examples from practice and real life, physical terminology in English, quizzes, competitions, interesting things and links related to discussed curriculum. The Workbook is divided into thematic sections, chapters and subchapters similar as physics textbooks for pupils of the 1st years of Secondary Schools in the Czech Republic. In the Workbook there are included tasks on fill in the words, polynomial tasks with choice answer "one right answer", tasks assignment, tasks to sketching to the pictures and physical tasks including graphic sketches. Long-term research through the Entrance test of physics and the use of the Workbook in physics teaching will continue in the school year 2016/2017 and not just among pupils of the 1st years of secondary vocational school, but also pupils at grammar school, where the research was conducted in the school year 2010/2011 and 2014/2015.

Human adaptations for the visual assessment of strength and fighting ability from the body and face

PubMed Central

Sell, Aaron; Cosmides, Leda; Tooby, John; Sznycer, Daniel; von Rueden, Christopher; Gurven, Michael

2008-01-01

Selection in species with aggressive social interactions favours the evolution of cognitive mechanisms for assessing physical formidability (fighting ability or resource-holding potential). The ability to accurately assess formidability in conspecifics has been documented in a number of non-human species, but has not been demonstrated in humans. Here, we report tests supporting the hypothesis that the human cognitive architecture includes mechanisms that assess fighting ability—mechanisms that focus on correlates of upper-body strength. Across diverse samples of targets that included US college students, Bolivian horticulturalists and Andean pastoralists, subjects in the US were able to accurately estimate the physical strength of male targets from photos of their bodies and faces. Hierarchical linear modelling shows that subjects were extracting cues of strength that were largely independent of height, weight and age, and that corresponded most strongly to objective measures of upper-body strength—even when the face was all that was available for inspection. Estimates of women's strength were less accurate, but still significant. These studies are the first empirical demonstration that, for humans, judgements of strength and judgements of fighting ability not only track each other, but accurately track actual upper-body strength. PMID:18945661

Advanced Multi-Physics (AMP)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Philip, Bobby

2012-06-01

The Advanced Multi-Physics (AMP) code, in its present form, will allow a user to build a multi-physics application code for existing mechanics and diffusion operators and extend them with user-defined material models and new physics operators. There are examples that demonstrate mechanics, thermo-mechanics, coupled diffusion, and mechanical contact. The AMP code is designed to leverage a variety of mathematical solvers (PETSc, Trilinos, SUNDIALS, and AMP solvers) and mesh databases (LibMesh and AMP) in a consistent interchangeable approach.

A Self-Paced Physical Geology Laboratory.

ERIC Educational Resources Information Center

Watson, Donald W.

1983-01-01

Describes a self-paced geology course utilizing a diversity of instructional techniques, including maps, models, samples, audio-visual materials, and a locally developed laboratory manual. Mechanical features are laboratory exercises, followed by unit quizzes; quizzes are repeated until the desired level of competence is attained. (Author/JN)

Seasonal patterns of estuarine acidification in seagrass beds of the Snohomish Estuary, WA

EPA Science Inventory

Recent studies have begun to explore physical and biogeochemical mechanisms of carbonate chemistry variability in a variety of coastal habitats, including coral reefs, upwelling margins, and inland seas. To our knowledge, there have been limited mechanistic studies of annual car...

Materials data handbook: Aluminum alloy 6061

NASA Technical Reports Server (NTRS)

Muraca, R. F.; Whittick, J. S.

1972-01-01

A summary of the materials property information for aluminum alloy 6061 is presented. The scope of the information includes physical and mechanical properties of the alloy at cryogenic, ambient, and elevated temperatures. Information on material procurement, metallurgy, corrosion, environmental effects, fabrication, and joining techniques is developed.

Materials data handbook: Stainless steel type 301

NASA Technical Reports Server (NTRS)

Muraca, R. F.; Whittick, J. S.

1972-01-01

A summary of the materials property information for stainless steel type 301 is presented. The scope of the information includes physical and mechanical properties at cryogenic, ambient, and elevated temperatures. Information on material procurement, metallurgy of the alloy, corrosion, environmental effects, fabrication, and bonding is developed.

Field evaluation of asphalt mixture skid resistance and its relationship to aggregate characteristics.

DOT National Transportation Integrated Search

2010-12-01

This report documents the findings from the research that was carried out as part of Phase II of Texas : Department of Transportation (TxDOT) Project 0-5627. The research included measuring and analyzing the : mechanical and physical properties of ag...

NASA Tech Briefs, March 1989. Volume 13, No. 3

NASA Technical Reports Server (NTRS)

1989-01-01

This issue's special features cover the NASA inventor of the year, and the other nominees for the year. Other Topics include: Electronic Components & and Circuits. Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Fabrication Technology, Mathematics and Information Sciences, and Life Sciences

Materials data handbook: Aluminum alloy 2219

NASA Technical Reports Server (NTRS)

Muraca, R. F.; Whittick, J. S.

1972-01-01

A summary of the materials property information for aluminum 2219 alloy is presented. The scope of the information includes physical and mechanical properties at cryogenic, ambient, and elevated temperatures. Information on material procurement, metallurgy of the alloy, corrosion, environmental effects, fabrication, and joining techniques is developed.

Materials data handbook: Aluminum alloy 7075

NASA Technical Reports Server (NTRS)

Muraca, R. F.; Whittick, J. S.

1972-01-01

A summary of the materials property information on aluminum alloy 7075 is presented. The scope of the information includes physical and mechanical properties of the alloy at cryogenic, ambient, and elevated temperatures. Information on material procurement, metallurgy, corrosion, environmental effects, fabrication, and joining techniques is developed.

Materials data handbooks on stainless steels

NASA Technical Reports Server (NTRS)

Muraca, R. F.; Whittick, J. S.

1973-01-01

Two handbooks which summarize latest available data have been published. Two types of stainless steels, alloy A-286 and Type 301, are described. Each handbook is divided into twelve chapters. Scope of information presented includes physical- and mechanical-property data at cryogenic, ambient, and elevated temperatures.

Materials data handbook: Aluminum alloy 5456

NASA Technical Reports Server (NTRS)

Muraca, R. F.; Whittick, J. S.

1972-01-01

A summary of the materials property information for aluminum alloy 5456 is presented. The scope of the information includes physical and mechanical property data at cryogenic, ambient, and elevated temperatures. Information on material procurement, metallurgy of the alloy, corrosion, environmental effects, fabrication, and joining techniques is developed.

NASA Tech Briefs, November 1998. Volume 22, No. 11

NASA Technical Reports Server (NTRS)

1998-01-01

Topics include: special coverage sections on test and measurement and sections on electronic components and circuits, electronic systems, software, materials, mechanics, machinery/automation, physical sciences, information sciences, book and reports, and special sections of Electronics Tech Briefs amd Rapid Product Development Tech Briefs.

Mansfield ISD. Integrated Lesson Plans.

ERIC Educational Resources Information Center

East Texas State Univ., Commerce. Educational Development and Training Center.

This packet contains 27 lesson plans for integrated academic and vocational education courses. Lesson plans for the following courses are included: horticulture, algebra, physical science, general mechanical repair, foods and nutrition, home economics, and microcomputer applications. Some of the topics covered are as follows: seed germination,…

Materials data handbook: Inconel alloy 718

NASA Technical Reports Server (NTRS)

Muraca, R. F.; Whittick, J. S.

1972-01-01

A summary of the materials property information for Inconel alloy 718 is presented. The scope of the information includes physical and mechanical properties at cryogenic, ambient, and elevated temperatures. Information on material procurement, metallurgy of the alloy, corrosion, environmental effects, fabrication, and joining techniques is developed.

Construction material processed using lunar simulant in various environments

NASA Technical Reports Server (NTRS)

Chase, Stan; Ocallaghan-Hay, Bridget; Housman, Ralph; Kindig, Michael; King, John; Montegrande, Kevin; Norris, Raymond; Vanscotter, Ryan; Willenborg, Jonathan; Staubs, Harry

1995-01-01

The manufacture of construction materials from locally available resources in space is an important first step in the establishment of lunar and planetary bases. The objective of the CoMPULSIVE (Construction Material Processed Using Lunar Simulant In Various Environments) experiment is to develop a procedure to produce construction materials by sintering or melting Johnson Space Center Simulant 1 (JSC-1) lunar soil simulant in both earth-based (1-g) and microgravity (approximately 0-g) environments. The characteristics of the resultant materials will be tested to determine its physical and mechanical properties. The physical characteristics include: crystalline, thermal, and electrical properties. The mechanical properties include: compressive tensile, and flexural strengths. The simulant, placed in a sealed graphite crucible, will be heated using a high temperature furnace. The crucible will then be cooled by radiative and forced convective means. The core furnace element consists of space qualified quartz-halogen incandescent lamps with focusing mirrors. Sample temperatures of up to 2200 C are attainable using this heating method.

Fabrication and characterisation of phantom material made of Tannin-added Rhizophora spp. particleboards for photon and electron beams

NASA Astrophysics Data System (ADS)

Yusof, M. F. Mohd; Hamid, P. N. K. Abd; Tajuddin, A. A.; Hashim, R.; Bauk, S.; Isa, N. Mohd; Isa, M. J. Md

2017-05-01

Particleboards made of Rhizophora spp. with addition of tannin adhesive were fabricated at target density of 1.0 g/cm3. The physical and mechanical properties of the particleboards including internal bond strength (IB) and modulus of rupture (MOR) were measured based on Japanese Industrial Standards (JIS A-5908). The characterisation of the particleboards including the effective atomic number, CT number and relative electron density were determined and compared to water. The mass attenuation coefficient of the particleboards were measured and compared to the calculated value of water using photon cross-section database (XCOM). The results showed that the physical and mechanical properties of the particleboards complied with Type 13 and 18 of JIS A-5908. The values of effective atomic number, CT number and relative electron density were also close to the value of water. The value of mass attenuation coefficients of the particleboards showed good agreement with water (XCOM) at low and high energy photon indicated by the χ2 values.

Fracture mechanism maps in unirradiated and irradiated metals and alloys

NASA Astrophysics Data System (ADS)

Li, Meimei; Zinkle, S. J.

2007-04-01

This paper presents a methodology for computing a fracture mechanism map in two-dimensional space of tensile stress and temperature using physically-based constitutive equations. Four principal fracture mechanisms were considered: cleavage fracture, low temperature ductile fracture, transgranular creep fracture, and intergranular creep fracture. The methodology was applied to calculate fracture mechanism maps for several selected reactor materials, CuCrZr, 316 type stainless steel, F82H ferritic-martensitic steel, V4Cr4Ti and Mo. The calculated fracture maps are in good agreement with empirical maps obtained from experimental observations. The fracture mechanism maps of unirradiated metals and alloys were modified to include radiation hardening effects on cleavage fracture and high temperature helium embrittlement. Future refinement of fracture mechanism maps is discussed.

Deformation Theory and Physics Model Building

NASA Astrophysics Data System (ADS)

Sternheimer, Daniel

2006-08-01

The mathematical theory of deformations has proved to be a powerful tool in modeling physical reality. We start with a short historical and philosophical review of the context and concentrate this rapid presentation on a few interrelated directions where deformation theory is essential in bringing a new framework - which has then to be developed using adapted tools, some of which come from the deformation aspect. Minkowskian space-time can be deformed into Anti de Sitter, where massless particles become composite (also dynamically): this opens new perspectives in particle physics, at least at the electroweak level, including prediction of new mesons. Nonlinear group representations and covariant field equations, coming from interactions, can be viewed as some deformation of their linear (free) part: recognizing this fact can provide a good framework for treating problems in this area, in particular global solutions. Last but not least, (algebras associated with) classical mechanics (and field theory) on a Poisson phase space can be deformed to (algebras associated with) quantum mechanics (and quantum field theory). That is now a frontier domain in mathematics and theoretical physics called deformation quantization, with multiple ramifications, avatars and connections in both mathematics and physics. These include representation theory, quantum groups (when considering Hopf algebras instead of associative or Lie algebras), noncommutative geometry and manifolds, algebraic geometry, number theory, and of course what is regrouped under the name of M-theory. We shall here look at these from the unifying point of view of deformation theory and refer to a limited number of papers as a starting point for further study.

Using Physical Models for Anomaly Detection in Control Systems

NASA Astrophysics Data System (ADS)

Svendsen, Nils; Wolthusen, Stephen

Supervisory control and data acquisition (SCADA) systems are increasingly used to operate critical infrastructure assets. However, the inclusion of advanced information technology and communications components and elaborate control strategies in SCADA systems increase the threat surface for external and subversion-type attacks. The problems are exacerbated by site-specific properties of SCADA environments that make subversion detection impractical; and by sensor noise and feedback characteristics that degrade conventional anomaly detection systems. Moreover, potential attack mechanisms are ill-defined and may include both physical and logical aspects.

High temperature polyimide foams for shuttle upper surface thermal insulation

NASA Technical Reports Server (NTRS)

Ball, G. L., III; Leffingwell, J. W.; Salyer, I. O.; Werkmeister, D. W.

1974-01-01

Polyimide foams developed by Monsanto Company were examined for use as upper surface space shuttle thermal insulation. It was found that postcured polyimide foams having a density of 64 kg/cu m (4 lb/cu ft) had acceptable physical properties up to and exceeding 700 K (800 F). Physical tests included cyclic heating and cooling in vacuum, weight and dimensional stability, mechanical strength and impact resistance, acoustic loading and thermal conductivity. Molding and newly developed postcuring procedures were defined.

Simulation of Asymmetric Destabilization of Mine-void Rock Masses Using a Large 3D Physical Model

NASA Astrophysics Data System (ADS)

Lai, X. P.; Shan, P. F.; Cao, J. T.; Cui, F.; Sun, H.

2016-02-01

When mechanized sub-horizontal section top coal caving (SSTCC) is used as an underground mining method for exploiting extremely steep and thick coal seams (ESTCS), a large-scale surrounding rock caving may be violently created and have the potential to induce asymmetric destabilization from mine voids. In this study, a methodology for assessing the destabilization was developed to simulate the Weihuliang coal mine in the Urumchi coal field, China. Coal-rock mass and geological structure characterization were integrated with rock mechanics testing for assessment of the methodology and factors influencing asymmetric destabilization. The porous rock-like composite material ensured accuracy for building a 3D geological physical model of mechanized SSTCC by combining multi-mean timely track monitoring including acoustic emission, crack optical acquirement, roof separation observation, and close-field photogrammetry. An asymmetric 3D modeling analysis for destabilization characteristics was completed. Data from the simulated hydraulic support and buried pressure sensor provided effective information that was linked with stress-strain relationship of the working face in ESTCS. The results of the 3D physical model experiments combined with hybrid statistical methods were effective for predicting dynamic hazards in ESTCS.

Is burnout related to allostatic load?

PubMed

Langelaan, Saar; Bakker, Arnold B; Schaufeli, Wilmar B; van Rhenen, Willem; van Doornen, Lorenz J P

2007-01-01

Burnout has a negative impact on physical health, but the mechanisms underlying this relation remain unclear. To elucidate these mechanisms, possible mediating physiological systems or risk factors for adverse health in burned-out employees should be investigated. The aim of the present study among 290 Dutch managers was to explore whether allostatic load mediates the relationship between burnout and physical health. Burned-out managers, as identified with the Maslach Burnout Inventory General Survey (MBI-GS), were compared with a healthy control group with regard to their allostatic load. The allostatic load index included eight parameters: Body-mass index (BMI), systolic and diastolic blood pressure (SBP and DBP), C-reactive protein (CRP), high-density lipoprotein (HDL), cholesterol, glycosylated hemoglobin (HbA1C) and glucose. Contrary to expectations, burned-out managers did not differ from healthy managers with regard to their scores on the allostatic load index. An additional analysis, using groups of managers in the extreme deciles of exhaustion (the core symptom of burnout), did also not reveal differences in allostatic load. Burnout seems not to be associated with this proxy measure of allostatic load. The mediating physiological mechanisms between burnout and objective physical health remain to be elucidated.

Computational Studies of Magnetic Nozzle Performance

NASA Technical Reports Server (NTRS)

Ebersohn, Frans H.; Longmier, Benjamin W.; Sheehan, John P.; Shebalin, John B.; Raja, Laxminarayan

2013-01-01

An extensive literature review of magnetic nozzle research has been performed, examining previous work, as well as a review of fundamental principles. This has allow us to catalog all basic physical mechanisms which we believe underlie the thrust generation process. Energy conversion mechanisms include the approximate conservation of the magnetic moment adiabatic invariant, generalized hall and thermoelectric acceleration, swirl acceleration, thermal energy transformation into directed kinetic energy, and Joule heating. Momentum transfer results from the interaction of the applied magnetic field with currents induced in the plasma plume., while plasma detachment mechanisms include resistive diffusion, recombination and charge exchange collisions, magnetic reconnection, loss of adiabaticity, inertial forces, current closure, and self-field detachment. We have performed a preliminary study of Hall effects on magnetic nozzle jets with weak guiding magnetic fields and weak expansions (p(sub jet) approx. = P(sub background)). The conclusion from this study is that the Hall effect creates an azimuthal rotation of the plasma jet and, more generally, creates helical structures in the induced current, velocity field, and magnetic fields. We have studied plasma jet expansion to near vacuum without a guiding magnetic field, and are presently including a guiding magnetic field using a resistive MHD solver. This research is progressing toward the implementation of a full generalized Ohm's law solver. In our paper, we will summarize the basic principle, as well as the literature survey and briefly review our previous results. Our most recent results at the time of submittal will also be included. Efforts are currently underway to construct an experiment at the University of Michigan Plasmadynamics and Electric Propulsion Laboratory (PEPL) to study magnetic nozzle physics for a RF-thruster. Our computational study will work directly with this experiment to validate the numerical model, in order to study magnetic nozzle physics and optimize magnetic nozzle design. Preliminary results from the PEPL experiment will also be presented.

Active Learning in PhysicsTechnology and Research-based Techniques Emphasizing Interactive Lecture Demonstrations

NASA Astrophysics Data System (ADS)

Thornton, Ronald

2010-10-01

Physics education research has shown that learning environments that engage students and allow them to take an active part in their learning can lead to large conceptual gains compared to traditional instruction. Examples of successful curricula and methods include Peer Instruction, Just in Time Teaching, RealTime Physics, Workshop Physics, Scale-Up, and Interactive Lecture Demonstrations (ILDs). An active learning environment is often difficult to achieve in lecture sessions. This presentation will demonstrate the use of sequences of Interactive Lecture Demonstrations (ILDs) that use real experiments often involving real-time data collection and display combined with student interaction to create an active learning environment in large or small lecture classes. Interactive lecture demonstrations will be done in the area of mechanics using real-time motion probes and the Visualizer. A video tape of students involved in interactive lecture demonstrations will be shown. The results of a number of research studies at various institutions (including international) to measure the effectiveness of ILDs and guided inquiry conceptual laboratories will be presented.

SmartSIM - a virtual reality simulator for laparoscopy training using a generic physics engine.

PubMed

Khan, Zohaib Amjad; Kamal, Nabeel; Hameed, Asad; Mahmood, Amama; Zainab, Rida; Sadia, Bushra; Mansoor, Shamyl Bin; Hasan, Osman

2017-09-01

Virtual reality (VR) training simulators have started playing a vital role in enhancing surgical skills, such as hand-eye coordination in laparoscopy, and practicing surgical scenarios that cannot be easily created using physical models. We describe a new VR simulator for basic training in laparoscopy, i.e. SmartSIM, which has been developed using a generic open-source physics engine called the simulation open framework architecture (SOFA). This paper describes the systems perspective of SmartSIM including design details of both hardware and software components, while highlighting the critical design decisions. Some of the distinguishing features of SmartSIM include: (i) an easy-to-fabricate custom-built hardware interface; (ii) use of a generic physics engine to facilitate wider accessibility of our work and flexibility in terms of using various graphical modelling algorithms and their implementations; and (iii) an intelligent and smart evaluation mechanism that facilitates unsupervised and independent learning. Copyright © 2016 John Wiley & Sons, Ltd.

Frontiers in Relativistic Celestial Mechanics, Vol. 2, Applications and Experiments

NASA Astrophysics Data System (ADS)

Kopeikin, Sergei

2014-08-01

Relativistic celestial mechanics - investigating the motion celestial bodies under the influence of general relativity - is a major tool of modern experimental gravitational physics. With a wide range of prominent authors from the field, this two-volume series consists of reviews on a multitude of advanced topics in the area of relativistic celestial mechanics - starting from more classical topics such as the regime of asymptotically-flat spacetime, light propagation and celestial ephemerides, but also including its role in cosmology and alternative theories of gravity as well as modern experiments in this area. This second volume of a two-volume series covers applications of the theory as well as experimental verifications. From tools to determine light travel times in curved space-time to laser ranging between earth and moon and between satellites, and impacts on the definition of time scales and clock comparison techniques, a variety of effects is discussed. On the occasion of his 80-th birthday, these two volumes honor V. A. Brumberg - one of the pioneers in modern relativistic celestial mechanics. Contributions include: J. Simon, A. Fienga: Victor Brumberg and the French school of analytical celestial mechanics T. Fukushima: Elliptic functions and elliptic integrals for celestial mechanics and dynamical astronomy P. Teyssandier: New tools for determining the light travel time in static, spherically symmetric spacetimes beyond the order G2 J. Müller, L. Biskupek, F. Hofmann and E. Mai: Lunar laser ranging and relativity N. Wex: Testing relativistic celestial mechanics with radio pulsars I. Ciufolini et al.: Dragging of inertial frames, fundamental physics, and satellite laser ranging G. Petit, P. Wolf, P. Delva: Atomic time, clocks, and clock comparisons in relativistic spacetime: a review

Explaining Today's Physics Through History and Biography

NASA Astrophysics Data System (ADS)

Lindley, David

2014-03-01

Quantum computers, string theory, holographic universes - to the general audience, today's physics can be as mystifying as it is fascinating. But modern ideas evolved from an earlier phase of physics - Newtonian mechanics, simple cause and effect - that is in principle easier for the non-expert to grasp. I have found that writing about physics from a historical and biographical perspective is an effective way to convey modern thinking by explaining where it comes from - it is a way of carrying the reader from concepts that make intuitive sense to ideas that seem, on first encounter, utterly bizarre. Smuggling explanations into stories satisfies the reader's desire for narrative - bearing in mind that narrative can include the evolution of ideas as well as tales about intriguing and original people.

Review of the physics of enhancing vortex lift by unsteady excitation

NASA Technical Reports Server (NTRS)

Wu, J. Z.; Vakili, A. D.; Wu, J. M.

1991-01-01

A review aimed at providing a physical understanding of the crucial mechanisms for obtaining super lift by means of unsteady excitations is presented. Particular attention is given to physical problems, including rolled-up vortex layer instability and receptivity, wave-vortex interaction and resonance, nonlinear streaming, instability of vortices behind bluff bodies and their shedding, and vortex breakdown. A general theoretical framework suitable for handling the unsteady vortex flows is introduced. It is suggested that wings with swept and sharp leading edges, equipped with devices for unsteady excitations, could yield the first breakthrough of the unsteady separation barrier and provide super lift at post-stall angle of attack.

Living matter—nexus of physics and biology in the 21st century

PubMed Central

Gardel, Margaret L.

2012-01-01

Cells are made up of complex assemblies of cytoskeletal proteins that facilitate force transmission from the molecular to cellular scale to regulate cell shape and force generation. The “living matter” formed by the cytoskeleton facilitates versatile and robust behaviors of cells, including their migration, adhesion, division, and morphology, that ultimately determine tissue architecture and mechanics. Elucidating the underlying physical principles of such living matter provides great opportunities in both biology and physics. For physicists, the cytoskeleton provides an exceptional toolbox to study materials far from equilibrium. For biologists, these studies will provide new understanding of how molecular-scale processes determine cell morphological changes. PMID:23112229

Quantum Mechanics - Fundamentals and Applications to Technology

NASA Astrophysics Data System (ADS)

Singh, Jasprit

1996-10-01

Explore the relationship between quantum mechanics and information-age applications This volume takes an altogether unique approach to quantum mechanics. Providing an in-depth exposition of quantum mechanics fundamentals, it shows how these concepts are applied to most of today's information technologies, whether they are electronic devices or materials. No other text makes this critical, essential leap from theory to real-world applications. The book's lively discussion of the mathematics involved fits right in with contemporary multidisciplinary trends in education: Once the basic formulation has been derived in a given chapter, the connection to important technological problems is summarily described. The many helpful features include * Twenty-eight application-oriented sections that focus on lasers, transistors, magnetic memories, superconductors, nuclear magnetic resonance (NMR), and other important technology-driving materials and devices * One hundred solved examples, with an emphasis on numerical results and the connection between the physics and its applications * End-of-chapter problems that ground the student in both fundamental and applied concepts * Numerous figures and tables to clarify the various topics and provide a global view of the problems under discussion * Over two hundred illustrations to highlight problems and text A book for the information age, Quantum Mechanics: Fundamentals and Applications to Technology promises to become a standard in departments of electrical engineering, applied physics, and materials science, as well as physics. It is an excellent text for senior undergraduate and graduate students, and a helpful reference for practicing scientists, engineers, and chemists in the semiconductor and electronic industries.

Concise Review: Plasma and Nuclear Membranes Convey Mechanical Information to Regulate Mesenchymal Stem Cell Lineage.

PubMed

Uzer, Gunes; Fuchs, Robyn K; Rubin, Janet; Thompson, William R

2016-06-01

Numerous factors including chemical, hormonal, spatial, and physical cues determine stem cell fate. While the regulation of stem cell differentiation by soluble factors is well-characterized, the role of mechanical force in the determination of lineage fate is just beginning to be understood. Investigation of the role of force on cell function has largely focused on "outside-in" signaling, initiated at the plasma membrane. When interfaced with the extracellular matrix, the cell uses integral membrane proteins, such as those found in focal adhesion complexes to translate force into biochemical signals. Akin to these outside-in connections, the internal cytoskeleton is physically linked to the nucleus, via proteins that span the nuclear membrane. Although structurally and biochemically distinct, these two forms of mechanical coupling influence stem cell lineage fate and, when disrupted, often lead to disease. Here we provide an overview of how mechanical coupling occurs at the plasma and nuclear membranes. We also discuss the role of force on stem cell differentiation, with focus on the biochemical signals generated at the cell membrane and the nucleus, and how those signals influence various diseases. While the interaction of stem cells with their physical environment and how they respond to force is complex, an understanding of the mechanical regulation of these cells is critical in the design of novel therapeutics to combat diseases associated with aging, cancer, and osteoporosis. Stem Cells 2016;34:1455-1463. © 2016 AlphaMed Press.

Physicochemical Control of Adult Stem Cell Differentiation: Shedding Light on Potential Molecular Mechanisms

DTIC Science & Technology

2010-01-01

stem - cell -based biomedical and therapeutic applications, including tissue engineering, requires an understanding of the cell-cell and cell-environment interactions. To this end, recent efforts have been focused on the manipulation of adult stem cell differentiation using inductive soluble factors, designing suitable mechanical environments, and applying noninvasive physical forces. Although each of these different approaches has been successfully applied to regulate stem cell differentiation, it would be of great interest and

Applications of optical holography to applied mechanics.

NASA Technical Reports Server (NTRS)

Aprahamian, R.

1972-01-01

This paper provides a brief summary of applications of optical holography and holographic interferometry to applied solid mechanics. Basic equations commonly used in fringe interpretation are described and used to reduce the data contained on holographic interferograms. A comparison of data obtained holographically with analytical prediction is given wherever possible. Applications contained herein include front surface physics, study of bomb breakup, transverse wave propagation, study of mode shapes of panels at elevated temperatures, nondestructive testing, and vibration analysis.

Soil mechanics results of Luna 16 and Lunokhod 1: A preliminary report

NASA Technical Reports Server (NTRS)

Johnson, S. W.; Carrier, W. D., III

1971-01-01

The physical and mechanical properties of the lunar soil, as determined by Luna 16 and Lunokhod 1 experiments, are discussed. Data are included for interactions between vehicle wheels and the lunar soil, compressibility, resistance to penetration, and friction characteristics of the soil. The shear strength of the returned lunar soil for various bulk densities is also examined. Several potential spacecraft materials were tested in contact with lunar soil to determine their friction and wear characteristics.

Harvesting wood for energy.

Treesearch

Rodger A. Arola; Edwin W. Miyata

1981-01-01

Illustrates the potential of harvesting wood for industrial energy, based on the results of five harvesting studies. Presents information on harvesting operations, equipment costs, and productivity. Discusses mechanized thinning of hardwoods, clearcutting of low-value stands and recovery of hardwood tops and limbs. Also includes basic information on the physical and...

NASA Tech Briefs, June 1998. Volume 22, No. 6

NASA Technical Reports Server (NTRS)

1998-01-01

Topics include: special coverage on computer hardware and peripherals, electronic components and circuits, electronic systems, software, materials, mechanics, machinery/automation, manufacturing, physical sciences, information sciences, book and reports, and a special section of Photonics Tech Briefs. and a second special section of Motion Control Tech Briefs

Field evaluation of asphalt mixture skid resistance and its relationship to aggregate characteristics.

DOT National Transportation Integrated Search

2011-08-01

This report documents the findings from the research that was carried out as part of Phase II of : TxDOT Project 0-5627. The research included measurements and analysis of mechanical and physical : properties of aggregates used in surface mixes in th...

NASA Tech Briefs, May 1999. Volume 23, No. 5

NASA Technical Reports Server (NTRS)

1999-01-01

Topics include: special coverage sections on sensors and composites and plastics, and sections on electronic components and systems, software, materials, mechanics, machinery and automation, bio-medical, physical sciences, book and reports, and a special section of Photonics Tech Briefs and Rapid Product Development Tech Briefs.

NASA Tech Briefs, October 1999. Volume 23, No. 10

NASA Technical Reports Server (NTRS)

1999-01-01

Topics include: special coverage section on data acquisition and sensors and sections on electronic components and systems, software, materials, mechanics, machinery/automation, manufacturing/fabrication, bio-medical, physical sciences, information sciences, book and reports, and special section of Electronics Tech Briefs and Motion Control Tech briefs

NASA Tech Briefs, March 1999. Volume 23, No. 3

NASA Technical Reports Server (NTRS)

1999-01-01

Topics include: special coverage sections on CAD/CAE/PDM, industrial controls and sections on electronic components systems, materials, software, mechanics, machinery/automation, manufacturing/fabrication, physical sciences, book and reports, and a special section of Photonics Tech Briefs and a seconds special section of Rapid Product Development.

Modulus of elasticity, creep and shrinkage of concrete, phase II : part 1, creep study, final report.

DOT National Transportation Integrated Search

2009-10-01

A laboratory testing program was performed to evaluate the physical and mechanical properties of typical Class II, IV, V, and VI concrete mixtures made with a Miami Oolite limestone, a Georgia granite, and a lightweight aggregate Stalite, including c...

Materials data handbook: Stainless steel alloy A-286

NASA Technical Reports Server (NTRS)

Muraca, R. F.; Whittick, J. S.

1972-01-01

A summary of the materials property information for stainless steel alloy A-286 is presented. The scope of the information includes physical and mechanical properties at cryogenic, ambient, and elevated temperatures. Information on material procurement, metallurgy of the alloy, corrosion, environmental effects, fabrication, and bonding is developed.

AMOEBA 2.0: A physics-first approach to biomolecular simulations

NASA Astrophysics Data System (ADS)

Rackers, Joshua; Ponder, Jay

The goal of the AMOEBA force field project is to use classical physics to understand and predict the nature of interactions between biological molecules. While making significant advances over the past decade, the ultimate goal of predicting binding energies with ``chemical accuracy'' remains elusive. The primary source of this inaccuracy comes from the physics of how molecules interact at short range. For example, despite AMOEBA's advanced treatment of electrostatics, the force field dramatically overpredicts the electrostatic energy of DNA stacking interactions. AMOEBA 2.0 works to correct these errors by including simple, first principles physics-based terms to account for the quantum mechanical nature of these short-range molecular interactions. We have added a charge penetration term that considerably improves the description of electrostatic interactions at short range. We are reformulating the polarization term of AMOEBA in terms of basic physics assertions. And we are reevaluating the van der Waals term to match ab initio energy decompositions. These additions and changes promise to make AMOEBA more predictive. By including more physical detail of the important short-range interactions of biological molecules, we hope to move closer to the ultimate goal of true predictive power.

Increasing Recreational Physical Activity in Patients With Chronic Low Back Pain: A Pragmatic Controlled Clinical Trial.

PubMed

Ben-Ami, Noa; Chodick, Gabriel; Mirovsky, Yigal; Pincus, Tamar; Shapiro, Yair

2017-02-01

Study Design Prospective, pragmatic, nonrandomized controlled clinical trial. Background Clinical guidelines recommend physical activity for the treatment of chronic low back pain. But engaging patients in physical activity has proven difficult. Known obstacles to physical activity include low self-efficacy and fear avoidance. Objectives This study tested the effectiveness of an enhanced transtheoretical model intervention (ETMI) aimed at increasing recreational physical activity in patients with chronic low back pain, in comparison to usual physical therapy. Methods Patients (n = 220) referred to physical therapy for chronic low back pain were allocated to ETMI or to a control group. The ETMI was delivered by physical therapists and based on behavior-change principles, combined with increased reassurance, therapeutic alliance, and exposure to reduce fear avoidance. The primary outcome was back pain-related disability (Roland-Morris Disability Questionnaire). Secondary outcomes included pain intensity, mental and physical health, and levels of physical activity. Results Intention-to-treat analysis in 189 patients at 12 months indicated that patients in the ETMI group had significantly lower disability compared to usual physical therapy. The difference in mean change from baseline between the interventions was 2.7 points (95% confidence interval: 0.9, 4.5) on the Roland-Morris Disability Questionnaire. At 12 months, worst pain, physical activity, and physical health were all significantly better in patients receiving ETMI. The average number of sessions was 3.5 for the ETMI group and 5.1 for controls. Conclusion Targeting obstacles to physical activity with an intervention that includes components to address self-efficacy and fear avoidance appears to be more effective than usual physical therapy care in reducing long-term disability. Further research is needed to explore the mechanisms that impact outcomes in this intervention package. Level of Evidence Therapy, level 2b. Registered June 7, 2012 at ClinicalTrials.gov (NCT01631344). J Orthop Sports Phys Ther 2017;47(2):57-66. doi:10.2519/jospt.2017.7057.

Emerging technologies for the non-invasive characterization of physical-mechanical properties of tablets.

PubMed

Dave, Vivek S; Shahin, Hend I; Youngren-Ortiz, Susanne R; Chougule, Mahavir B; Haware, Rahul V

2017-10-30

The density, porosity, breaking force, viscoelastic properties, and the presence or absence of any structural defects or irregularities are important physical-mechanical quality attributes of popular solid dosage forms like tablets. The irregularities associated with these attributes may influence the drug product functionality. Thus, an accurate and efficient characterization of these properties is critical for successful development and manufacturing of a robust tablets. These properties are mainly analyzed and monitored with traditional pharmacopeial and non-pharmacopeial methods. Such methods are associated with several challenges such as lack of spatial resolution, efficiency, or sample-sparing attributes. Recent advances in technology, design, instrumentation, and software have led to the emergence of newer techniques for non-invasive characterization of physical-mechanical properties of tablets. These techniques include near infrared spectroscopy, Raman spectroscopy, X-ray microtomography, nuclear magnetic resonance (NMR) imaging, terahertz pulsed imaging, laser-induced breakdown spectroscopy, and various acoustic- and thermal-based techniques. Such state-of-the-art techniques are currently applied at various stages of development and manufacturing of tablets at industrial scale. Each technique has specific advantages or challenges with respect to operational efficiency and cost, compared to traditional analytical methods. Currently, most of these techniques are used as secondary analytical tools to support the traditional methods in characterizing or monitoring tablet quality attributes. Therefore, further development in the instrumentation and software, and studies on the applications are necessary for their adoption in routine analysis and monitoring of tablet physical-mechanical properties. Copyright © 2017 Elsevier B.V. All rights reserved.

Reversible nano-lithography for commercial approaches

NASA Astrophysics Data System (ADS)

Park, Jae Hong; Jang, Hyun Ik; Kim, Woo Choong; Yun, Hae S.; Park, Jun Yong; Jeon, Seok Woo; Kim, Hee Yeoun; Ahn, Chi Won

2016-04-01

The methodology suggested in this research provides the great possibility of creating nanostructures composed of various materials, such as soft polymer, hard polymer, and metal, as well as Si. Such nanostructures are required for a vast range of optical and display devices, photonic components, physical devices, energy devices including electrodes of secondary batteries, fuel cells, solar cells, and energy harvesters, biological devices including biochips, biomimetic or biosimilar structured devices, and mechanical devices including micro- or nano-scale sensors and actuators.

Driven to be inactive? The genetics of physical activity.

PubMed

Moore-Harrison, Trudy; Lightfoot, J Timothy

2010-01-01

The health implications of physical inactivity, including its integral role in promoting obesity, are well known and have been well documented. Physical activity is a multifactorial behavior with various factors playing a role in determining individual physical activity levels. Research using both human and animal models in the past several years has clearly indicated that genetics is associated with physical activity. Furthermore, researchers have identified several significant and suggestive genomic quantitative trait loci associated with physical activity. To date, the identities of the causal genes underlying physical activity regulation are unclear, with few strong candidate genes. The current research provides a foundation from which future confirmatory research can be launched as well as determination of the mechanisms through which the genetic factors act. The application of this knowledge could significantly augment the information available for physical activity behavior change interventions resulting in more efficient programs for those predisposed to be inactive. Copyright © 2010 Elsevier Inc. All rights reserved.

The test of Tensile Properties and Water Resistance of a Novel Cross-linked Starch Prepared by Adding Oil-Flax

NASA Astrophysics Data System (ADS)

Shi, Dawei; Wang, Rui

2017-12-01

In this study, to solve the poor water resistance and the low mechanical properties of starch, a mixed-starch composite matrix which including glycerol, sorbitol, and urea, were prepared via single-crew extrusion, then adding oil-flax to improve its physical mechanical and used to a source of biodegradable plastics material. The composite matrix was systematically characterized using various analytic tools including XRD, SEM and TG. The composite showed a maximum tensile strength of 18.11Mpa and moisture absorption 17.67%, while the original starch matrix was only 12.51 Mpa and 24.98%, respectively.

Investigating student understanding of simple harmonic motion

NASA Astrophysics Data System (ADS)

Somroob, S.; Wattanakasiwich, P.

2017-09-01

This study aimed to investigate students’ understanding and develop instructional material on a topic of simple harmonic motion. Participants were 60 students taking a course on vibrations and wave and 46 students taking a course on Physics 2 and 28 students taking a course on Fundamental Physics 2 on the 2nd semester of an academic year 2016. A 16-question conceptual test and tutorial activities had been developed from previous research findings and evaluated by three physics experts in teaching mechanics before using in a real classroom. Data collection included both qualitative and quantitative methods. Item analysis and whole-test analysis were determined from student responses in the conceptual test. As results, most students had misconceptions about restoring force and they had problems connecting mathematical solutions to real motions, especially phase angle. Moreover, they had problems with interpreting mechanical energy from graphs and diagrams of the motion. These results were used to develop effective instructional materials to enhance student abilities in understanding simple harmonic motion in term of multiple representations.

Quantum correlations and dynamics from classical random fields valued in complex Hilbert spaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khrennikov, Andrei

2010-08-15

One of the crucial differences between mathematical models of classical and quantum mechanics (QM) is the use of the tensor product of the state spaces of subsystems as the state space of the corresponding composite system. (To describe an ensemble of classical composite systems, one uses random variables taking values in the Cartesian product of the state spaces of subsystems.) We show that, nevertheless, it is possible to establish a natural correspondence between the classical and the quantum probabilistic descriptions of composite systems. Quantum averages for composite systems (including entangled) can be represented as averages with respect to classical randommore » fields. It is essentially what Albert Einstein dreamed of. QM is represented as classical statistical mechanics with infinite-dimensional phase space. While the mathematical construction is completely rigorous, its physical interpretation is a complicated problem. We present the basic physical interpretation of prequantum classical statistical field theory in Sec. II. However, this is only the first step toward real physical theory.« less

Anisotropic physical properties of myocardium characterized by ultrasonic measurements of backscatter, attenuation, and velocity

NASA Astrophysics Data System (ADS)

Baldwin, Steven L.

The goal of elucidating the physical mechanisms underlying the propagation of ultrasonic waves in anisotropic soft tissue such as myocardium has posed an interesting and largely unsolved problem in the field of physics for the past 30 years. In part because of the vast complexity of the system being studied, progress towards understanding and modeling the mechanisms that underlie observed acoustic parameters may first require the guidance of careful experiment. Knowledge of the causes of observed ultrasonic properties in soft tissue including attenuation, speed of sound, and backscatter, and how those properties are altered with specific pathophysiologies, may lead to new noninvasive approaches to the diagnosis of disease. The primary aim of this Dissertation is to contribute to an understanding of the physics that underlies the mechanisms responsible for the observed interaction of ultrasound with myocardium. To this end, through-transmission and backscatter measurements were performed by varying acoustic properties as a function of angle of insonification relative to the predominant myofiber direction and by altering the material properties of myocardium by increased protein cross-linking induced by chemical fixation as an extreme form of changes that may occur in certain pathologies such as diabetes. Techniques to estimate acoustic parameters from backscatter were broadened and challenges to implementing these techniques in vivo were addressed. Provided that specific challenges identified in this Dissertation can be overcome, techniques to estimate attenuation from ultrasonic backscatter show promise as a means to investigate the physical interaction of ultrasound with anisotropic biological media in vivo. This Dissertation represents a step towards understanding the physics of the interaction of ultrasonic waves with anisotropic biological media.

Mechanics of additively manufactured biomaterials.

PubMed

Zadpoor, Amir A

2017-06-01

Additive manufacturing (3D printing) has found many applications in healthcare including fabrication of biomaterials as well as bioprinting of tissues and organs. Additively manufactured (AM) biomaterials may possess arbitrarily complex micro-architectures that give rise to novel mechanical, physical, and biological properties. The mechanical behavior of such porous biomaterials including their quasi-static mechanical properties and fatigue resistance is not yet well understood. It is particularly important to understand the relationship between the designed micro-architecture (topology) and the resulting mechanical properties. The current special issue is dedicated to understanding the mechanical behavior of AM biomaterials. Although various types of AM biomaterials are represented in the special issue, the primary focus is on AM porous metallic biomaterials. As a prelude to this special issue, this editorial reviews some of the latest findings in the mechanical behavior of AM porous metallic biomaterials so as to describe the current state-of-the-art and set the stage for the other studies appearing in the issue. Some areas that are important for future research are also briefly mentioned. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pragmatic information in biology and physics.

PubMed

Roederer, Juan G

2016-03-13

I will show how an objective definition of the concept of information and the consideration of recent results about information processing in the human brain help clarify some fundamental aspects of physics and biology. Rather than attempting to define information ab initio, I introduce the concept of interaction between material bodies as a primary concept. Two distinct categories can be identified: (i) interactions which can always be reduced to a superposition of physical interactions (forces) between elementary constituents; and (ii) interactions between complex bodies which cannot be expressed as a superposition of interactions between parts, and in which patterns and forms (in space and/or time) play the determining role. Pragmatic information is then defined as the link between a given pattern and the ensuing pattern-specific change. I will show that pragmatic information is a biological concept; it plays no active role in the purely physical domain-it only does so when a living organism intervenes. The consequences for physics (including foundations of quantum mechanics) and biology (including brain function) will be discussed. This will include speculations about three fundamental transitions, from the quantum to the classical domain, from natural inanimate to living systems, and from subhuman to human brain information-processing operations, introduced here in their direct connection with the concept of pragmatic information. © 2016 The Author(s).

Unfolding of Proteins: Thermal and Mechanical Unfolding

NASA Technical Reports Server (NTRS)

Hur, Joe S.; Darve, Eric

2004-01-01

We have employed a Hamiltonian model based on a self-consistent Gaussian appoximation to examine the unfolding process of proteins in external - both mechanical and thermal - force elds. The motivation was to investigate the unfolding pathways of proteins by including only the essence of the important interactions of the native-state topology. Furthermore, if such a model can indeed correctly predict the physics of protein unfolding, it can complement more computationally expensive simulations and theoretical work. The self-consistent Gaussian approximation by Micheletti et al. has been incorporated in our model to make the model mathematically tractable by signi cantly reducing the computational cost. All thermodynamic properties and pair contact probabilities are calculated by simply evaluating the values of a series of Incomplete Gamma functions in an iterative manner. We have compared our results to previous molecular dynamics simulation and experimental data for the mechanical unfolding of the giant muscle protein Titin (1TIT). Our model, especially in light of its simplicity and excellent agreement with experiment and simulation, demonstrates the basic physical elements necessary to capture the mechanism of protein unfolding in an external force field.

How phloem-feeding insects face the challenge of phloem-located defenses

PubMed Central

Will, Torsten; Furch, Alexandra C. U.; Zimmermann, Matthias R.

2013-01-01

Due to the high content of nutrient, sieve tubes are a primary target for pests, e.g., most phytophagous hemipteran. To protect the integrity of the sieve tubes as well as their content, plants possess diverse chemical and physical defense mechanisms. The latter mechanisms are important because they can potentially interfere with the food source accession of phloem-feeding insects. Physical defense mechanisms are based on callose as well as on proteins and often plug the sieve tube. Insects that feed from sieve tubes are potentially able to overwhelm these defense mechanisms using their saliva. Gel saliva forms a sheath in the apoplast around the stylet and is suggested to seal the stylet penetration site in the cell plasma membrane. In addition, watery saliva is secreted into penetrated cells including sieve elements; the presence of specific enzymes/effectors in this saliva is thought to interfere with plant defense responses. Here we detail several aspects of plant defense and discuss the interaction of plants and phloem-feeding insects. Recent agro-biotechnological phloem-located aphid control strategies are presented. PMID:24009620

Five year magnetic tape for unattended satellite tape recorders

NASA Technical Reports Server (NTRS)

Benn, G. S. L.; Gutfreund, K.

1972-01-01

The development and fabrication of a quantity of long life magnetic tape with properties selected specifically for unattended operation in spacecraft tape recorders was studied. A detailed analytical consideration of various binder systems was undertaken. This included the chemical aspects of the binders, cohesion and adhesion effects, stability and the mechanical and physical properties. The ability to form free films of these polymers and their combination with various oxide loadings and other additives allowed a rapid selection of four polymer candidates for a five year magnetic tape. Samples were evaluated under actual running conditions which included physical, magnetic, and extensive life testing. These sample tapes withstood 50,000 bidirectional tape passes under fairly harsh operating conditions.

Perspectives on Home Care Quality

PubMed Central

Kane, Rosalie A.; Kane, Robert L.; Illston, Laurel H.; Eustis, Nancy N.

1994-01-01

Home care quality assurance (QA) must consider features inherent in home care, including: multiple goals, limited provider control, and unique family roles. Successive panels of stakeholders were asked to rate the importance of selected home care outcomes. Most highly rated outcomes were freedom from exploitation, satisfaction with care, physical safety, affordability, and physical functioning. Panelists preferred outcome indicators to process and structure, and all groups emphasized “enabling” criteria. Themes highlighted included: interpersonal components of care; normalizing life for clientele; balancing quality of life with safety; developing flexible, negotiated care plans; mechanisms for accountability and case management. These themes were formulated differently according to the stakeholders' role. Providers preferred intermediate outcomes, akin to process. PMID:10140158

Physically based modeling of bedrock incision by abrasion, plucking, and macroabrasion

NASA Astrophysics Data System (ADS)

Chatanantavet, Phairot; Parker, Gary

2009-11-01

Many important insights into the dynamic coupling among climate, erosion, and tectonics in mountain areas have derived from several numerical models of the past few decades which include descriptions of bedrock incision. However, many questions regarding incision processes and morphology of bedrock streams still remain unanswered. A more mechanistically based incision model is needed as a component to study landscape evolution. Major bedrock incision processes include (among other mechanisms) abrasion by bed load, plucking, and macroabrasion (a process of fracturing of the bedrock into pluckable sizes mediated by particle impacts). The purpose of this paper is to develop a physically based model of bedrock incision that includes all three processes mentioned above. To build the model, we start by developing a theory of abrasion, plucking, and macroabrasion mechanisms. We then incorporate hydrology, the evaluation of boundary shear stress, capacity transport, an entrainment relation for pluckable particles, a routing model linking in-stream sediment and hillslopes, a formulation for alluvial channel coverage, a channel width relation, Hack's law, and Exner equation into the model so that we can simulate the evolution of bedrock channels. The model successfully simulates various features of bed elevation profiles of natural bedrock rivers under a variety of input or boundary conditions. The results also illustrate that knickpoints found in bedrock rivers may be autogenic in addition to being driven by base level fall and lithologic changes. This supports the concept that bedrock incision by knickpoint migration may be an integral part of normal incision processes. The model is expected to improve the current understanding of the linkage among physically meaningful input parameters, the physics of incision process, and morphological changes in bedrock streams.

Method to study cell migration under uniaxial compression

PubMed Central

Srivastava, Nishit; Kay, Robert R.; Kabla, Alexandre J.

2017-01-01

The chemical, physical, and mechanical properties of the extracellular environment have a strong effect on cell migration. Aspects such as pore size or stiffness of the matrix influence the selection of the mechanism used by cells to propel themselves, including by pseudopods or blebbing. How a cell perceives its environment and how such a cue triggers a change in behavior are largely unknown, but mechanics is likely to be involved. Because mechanical conditions are often controlled by modifying the composition of the environment, separating chemical and physical contributions is difficult and requires multiple controls. Here we propose a simple method to impose a mechanical compression on individual cells without altering the composition of the matrix. Live imaging during compression provides accurate information about the cell's morphology and migratory phenotype. Using Dictyostelium as a model, we observe that a compression of the order of 500 Pa flattens the cells under gel by up to 50%. This uniaxial compression directly triggers a transition in the mode of migration from primarily pseudopodial to bleb driven in <30 s. This novel device is therefore capable of influencing cell migration in real time and offers a convenient approach with which to systematically study mechanotransduction in confined environments. PMID:28122819

Unified formalism for higher order non-autonomous dynamical systems

NASA Astrophysics Data System (ADS)

Prieto-Martínez, Pedro Daniel; Román-Roy, Narciso

2012-03-01

This work is devoted to giving a geometric framework for describing higher order non-autonomous mechanical systems. The starting point is to extend the Lagrangian-Hamiltonian unified formalism of Skinner and Rusk for these kinds of systems, generalizing previous developments for higher order autonomous mechanical systems and first-order non-autonomous mechanical systems. Then, we use this unified formulation to derive the standard Lagrangian and Hamiltonian formalisms, including the Legendre-Ostrogradsky map and the Euler-Lagrange and the Hamilton equations, both for regular and singular systems. As applications of our model, two examples of regular and singular physical systems are studied.

Gesellschaft fuer angewandte Mathematik und Mechanik, Annual Scientific Meeting, Universitaet Regensburg, Regensburg, West Germany, April 16-19, 1984, Proceedings

NASA Astrophysics Data System (ADS)

Problems in applied mathematics and mechanics are addressed in reviews and reports. Areas covered are vibration and stability, elastic and plastic mechanics, fluid mechanics, the numerical treatment of differential equations (general theory and finite-element methods in particular), optimization, decision theory, stochastics, actuarial mathematics, applied analysis and mathematical physics, and numerical analysis. Included are major lectures on separated flows, the transition regime of rarefied-gas dynamics, recent results in nonlinear elasticity, fluid-elastic vibration, the new computer arithmetic, and unsteady wave propagation in layered elastic bodies.

Teaching Quantum Mechanics through Project-based Learning

NASA Astrophysics Data System (ADS)

Duda, Gintaras; Ward, Kristina

2014-03-01

Project/Problem-based learning (PBL) is an active area of research within the physics education research (PER) community, however, work done to date has focused on introductory courses. This talk will explore research on upper division quantum mechanics, a junior/senior level course at Creighton University, which was taught using PBL pedagogy with no in-class lectures. Course time was primarily spent on lecture tutorials and projects, which included alpha decay of Uranium, neutrino oscillations, and FTIR spectroscopy of HCl. This talk will explore: 1. student learning in light of the new pedagogy and embedded meta-cognitive self-monitoring exercises, 2. the effect of the PBL curriculum on student attitudes, motivation, and students' epistemologies, and 3. the use of explicit written reflections within a physics course to probe student understanding.

QSPR models for various physical properties of carbohydrates based on molecular mechanics and quantum chemical calculations.

PubMed

Dyekjaer, Jane Dannow; Jónsdóttir, Svava Osk

2004-01-22

Quantitative Structure-Property Relationships (QSPR) have been developed for a series of monosaccharides, including the physical properties of partial molar heat capacity, heat of solution, melting point, heat of fusion, glass-transition temperature, and solid state density. The models were based on molecular descriptors obtained from molecular mechanics and quantum chemical calculations, combined with other types of descriptors. Saccharides exhibit a large degree of conformational flexibility, therefore a methodology for selecting the energetically most favorable conformers has been developed, and was used for the development of the QSPR models. In most cases good correlations were obtained for monosaccharides. For five of the properties predictions were made for disaccharides, and the predicted values for the partial molar heat capacities were in excellent agreement with experimental values.

Ion-Neutral Coupling in Solar Prominence

NASA Technical Reports Server (NTRS)

Gilbert, H.; DeVore, C. R.; Karpen, J.; Kucera, T.; Antiochos, S.; Kawashima, R.

2011-01-01

Coupling between ions and neutrals in magnetized plasmas is fundamentally important to many aspects of heliophysics, including our ionosphere, the solar chromosphere, the solar wind interaction with planetary atmospheres, and the interface between the heliosphere and the interstellar medium. Ion-neutral coupling also plays a major role in the physics of solar prominences. By combining theory, modeling, and observations we are working toward a better understanding of the structure and dynamics of partially ionized prominence plasma. Two key questions are addressed in the present work: 1) what physical mechanism(s) sets the cross-field scale of prominence threads? 2) Are ion-neutral interactions responsible for the vertical flows and structure in prominences? We present initial results from a study investigating what role ion-neutral interactions play in prominence dynamics and structure. This research was supported by NASA.

RF stabilization of plasma instabilities: a note on physical mechanism

NASA Astrophysics Data System (ADS)

Sen, S.; Martinell, J.; Imadera, K.; Kishimoto, Y.; Vahala, G.

2018-02-01

In a series of recent works, we have developed models including realistic spatial profiles of both flow and radio-frequency-induced ponderomotive force. With these inclusions, the picture of stability of various plasma and fluid instabilities is expected to be changed drastically with ground-breaking consequences. The inhomogeneous parallel flow and the radio-frequency waves can actually stabilize turbulence. This is different from the prevalent notion that both parallel flow shear and radio-frequency waves are responsible for the excitation (destabilization) of plasma turbulence. This model thus aims to open-up new channels and provide a major breakthrough in our knowledge of plasma and fluid turbulence and its consequent roles in energy, space and processing technology. In this short note, we elucidate the physical mechanism behind this novel observation.

Exploring Physics with Computer Animation and PhysGL

NASA Astrophysics Data System (ADS)

Bensky, T. J.

2016-10-01

This book shows how the web-based PhysGL programming environment (http://physgl.org) can be used to teach and learn elementary mechanics (physics) using simple coding exercises. The book's theme is that the lessons encountered in such a course can be used to generate physics-based animations, providing students with compelling and self-made visuals to aid their learning. Topics presented are parallel to those found in a traditional physics text, making for straightforward integration into a typical lecture-based physics course. Users will appreciate the ease at which compelling OpenGL-based graphics and animations can be produced using PhysGL, as well as its clean, simple language constructs. The author argues that coding should be a standard part of lower-division STEM courses, and provides many anecdotal experiences and observations, that include observed benefits of the coding work.

Preparing the NDE engineers of the future: Education, training, and diversity

NASA Astrophysics Data System (ADS)

Holland, Stephen D.

2017-02-01

As quantitative NDE has matured and entered the mainstream, it has created an industry need for engineers who can select, evaluate, and qualify NDE techniques to satisfy quantitative engineering requirements. NDE as a field is cross-disciplinary with major NDE techniques relying on a broad spectrum of physics disciplines including fluid mechanics, electromagnetics, mechanical waves, and high energy physics. An NDE engineer needs broad and deep understanding of the measurement physics across modalities, a general engineering background, and familiarity with shop-floor practices and tools. While there are a wide range of certification and training programs worldwide for NDE technicians, there are few programs aimed at engineers. At the same time, substantial demographic shifts are underway with many experienced NDE engineers and technicians nearing retirement, and with new generations coming from much more diverse backgrounds. There is a need for more and better education opportunities for NDE engineers. Both teaching and learning NDE engineering are inherently challenging because of the breadth and depth of knowledge required. At the same time, sustaining the field in a more diverse era will require broadening participation of previously underrepresented groups. The QNDE 2016 conference in Atlanta, GA included a session on NDE education, training, and diversity. This paper summarizes the outcomes and discussion from this session.

The Association Between Nutritional Adequacy and Long-Term Outcomes in Critically Ill Patients Requiring Prolonged Mechanical Ventilation: A Multicenter Cohort Study.

PubMed

Wei, Xuejiao; Day, Andrew G; Ouellette-Kuntz, Hélène; Heyland, Daren K

2015-08-01

To examine the association between short-term nutritional adequacy received while in the ICU and long-term outcomes including 6-month survival and health-related quality of life in critically ill patients requiring prolonged mechanical ventilation. Retrospective analysis of data prospectively collected in the context of a multicenter randomized controlled trial. An international sample of ICUs. Adult patients who were mechanically ventilated for more than 8 days in the ICU. None. Nutritional adequacy was obtained from the average proportion of prescribed calories received over the amount prescribed during the first 8 days. Survival status and health-related quality of life as assessed using the Short-Form 36 v2 were obtained at 3- and 6 months post ICU admission. Of the 1,223 patients enrolled in the randomized controlled trial, 475 met the inclusion criteria for this study. At 6-month follow-up, 302 of the 475 patients (64%) were alive. Survival time in those who received low nutritional adequacy was significantly shorter than those who received high nutritional adequacy while adjusting for important covariates (adjusted hazard ratio, 1.7; 95% CI, 1.1-2.6). At 3-month follow-up, a 25% increase in nutritional adequacy was associated with improvements in Physical Functioning and Role Physical of 7.3 (p = 0.02) and 8.3 (p = 0.004) points, respectively. At 6-month follow-up, adjusted increases in Physical Functioning and Role Physical scores for every 25% increase in nutrition adequacy became smaller and were no longer statistically significant (adjusted estimate for Physical Functioning = 4.2, p = 0.14; for Role Physical = 3.2, p = 0.25). Greater amounts of nutritional intake received during the first week in the ICU were associated with longer survival time and faster physical recovery to 3 months but not 6 months post ICU discharge in critically ill patients requiring prolonged mechanical ventilation. Current recommendations to underfeed critically ill patients may cause harm in some long-stay patients.

What do Seniors Remember from Freshman Physics?

NASA Astrophysics Data System (ADS)

Barrantes, Analia; Pawl, Andrew; Pritchard, David E.

2009-11-01

We have given a group of 56 MIT seniors who took mechanics as freshmen a written test similar to the final exam they took in their freshman course, plus the Mechanics Baseline Test (MBT) and Colorado Learning Attitudes about Science Survey (C-LASS) standard instruments. Students in majors unrelated to physics scored 60% lower on the written analytic part of the final than they did as freshmen. The mean score of all students on conceptual multiple choice questions included on the final also declined by about 60% relative to the scores of freshmen. The mean score of all participants on the MBT was insignificantly changed from the posttest taken as freshmen. More specifically, however, the students' performance on 9 of the 26 MBT items (with 6 of the 9 involving graphical kinematics) represents a gain over their freshman pretest score (a normalized gain of about 70%, double the gain achieved in the freshman course alone), while their performance on the remaining 17 questions is best characterized as a loss of approximately 50% of the material learned in the freshman course. Attitudinal survey results indicate that almost half the seniors feel the specific mechanics course content is unlikely to be useful to them, a significant majority (75-85%) feel that physics does teach valuable skills, and an overwhelming majority believe that mechanics should remain a required course at MIT.

FtsZ rings and helices: physical mechanisms for the dynamic alignment of biopolymers in rod-shaped bacteria.

PubMed

Fischer-Friedrich, Elisabeth; Friedrich, Benjamin M; Gov, Nir S

2012-02-01

In many bacterial species, the protein FtsZ forms a cytoskeletal ring that marks the future division site and scaffolds the division machinery. In rod-shaped bacteria, most frequently membrane-attached FtsZ rings or ring fragments are reported and occasionally helices. By contrast, axial FtsZ clusters have never been reported. In this paper, we investigate theoretically how dynamic FtsZ aggregates align in rod-shaped bacteria. We study systematically different physical mechanisms that affect the alignment of FtsZ polymers using a computational model that relies on autocatalytic aggregation of FtsZ filaments at the membrane. Our study identifies a general tool kit of physical and geometrical mechanisms by which rod-shaped cells align biopolymer aggregates. Our analysis compares the relative impact of each mechanism on the circumferential alignment of FtsZ as observed in rod-shaped bacteria. We determine spontaneous curvature of FtsZ polymers and axial confinement of FtsZ on the membrane as the strongest factors. Including Min oscillations in our model, we find that these stabilize axial and helical clusters on short time scales, but promote the formation of an FtsZ ring at the cell middle at longer times. This effect could provide an explanation to the long standing puzzle of transiently observed oscillating FtsZ helices in Escherichia coli cells prior to cell division.

Cultivating Engagement and Enjoyment in Exergames Using Feedback, Challenge, and Rewards.

PubMed

Lyons, Elizabeth J

2015-02-01

This article reviews theoretical and empirical evidence related to three mechanisms for encouraging enjoyment during exergame play: Feedback, challenge, and rewards. A literature search and narrative review were conducted. Feedback is found in nearly all exergames, and richer, more in-depth feedback is associated with increased activity. Challenge is a vital component of any videogame, and exergames include physical as well as cognitive challenges. Flow states have traditionally been conceptualized as occurring when an optimal match between player skills and game challenge occurs. However, failure and retrial are necessary for feelings of overall satisfaction and fun, despite not necessarily being ideally fun or satisfying themselves. Rewards are a more complicated issue, with significant theoretical and empirical evidence suggesting positive and negative effects of reward systems. How rewards are integrated into the mechanics and storyline of the game likely impacts how they are perceived and, thus, their effectiveness. Finally, integration of these mechanisms into exergames requires specific attention to both cognitive and physical implementations. Movements that are not themselves enjoyable or engaging may lead to cheating and lower energy expenditure. Feedback, challenge, and rewards are promising mechanisms by which exergames could become more enjoyable. How these concepts are operationalized can affect physical and psychological reactions to exergames. Attention to these concepts in future exergame development and implementation would benefit theory, research, and practice.

Cultivating Engagement and Enjoyment in Exergames Using Feedback, Challenge, and Rewards

PubMed Central

2015-01-01

Abstract Objective: This article reviews theoretical and empirical evidence related to three mechanisms for encouraging enjoyment during exergame play: Feedback, challenge, and rewards. Materials and Methods: A literature search and narrative review were conducted. Results: Feedback is found in nearly all exergames, and richer, more in-depth feedback is associated with increased activity. Challenge is a vital component of any videogame, and exergames include physical as well as cognitive challenges. Flow states have traditionally been conceptualized as occurring when an optimal match between player skills and game challenge occurs. However, failure and retrial are necessary for feelings of overall satisfaction and fun, despite not necessarily being ideally fun or satisfying themselves. Rewards are a more complicated issue, with significant theoretical and empirical evidence suggesting positive and negative effects of reward systems. How rewards are integrated into the mechanics and storyline of the game likely impacts how they are perceived and, thus, their effectiveness. Finally, integration of these mechanisms into exergames requires specific attention to both cognitive and physical implementations. Movements that are not themselves enjoyable or engaging may lead to cheating and lower energy expenditure. Conclusions: Feedback, challenge, and rewards are promising mechanisms by which exergames could become more enjoyable. How these concepts are operationalized can affect physical and psychological reactions to exergames. Attention to these concepts in future exergame development and implementation would benefit theory, research, and practice. PMID:26181675

Mineralogic, Petrographic, Mechanical And Physical Properties Of Incesu Ignimbrite (Central Anatolia - Turkey) Used Building Stone In Historical Buildings

NASA Astrophysics Data System (ADS)

Tasdelen, S.; Korolay, T.; Kadioglu, Y. K.; Kumral, M.

2009-05-01

The Central Anatolian Volcanic Province (CAVP) is located in the Central Turkey and one of the four major volcanic provinces in Turkey. It extends 300 km along a NE-SW direction, over a large area (32500 km2). The CAVP includes various volcanic, pyroclastic rocks, which are related to collision volcanism between the Arabian and Eurasian plates, occurred in Neogene, and Quaternary times There are numerous natural stone pits in the CAVP. They have been commonly used in historical building which had been built in the Anatolian Seljuk and Ottoman empires times. The subject of this study is to figure out petrographic, geochemical, some mechanical and physical properties which include Schmidt hardness, density, porosity, water absorption by weight, point load index and failure load.Incesu ignimbrite is subdivided into three levels as lower, middle and upper according to color, welding degree, crystal contents and lithic components. All of the natural stone pits is the upper part which is characterized by grey pinkish in color, poorly welded, high porosity ratios, high amount of lithic fragments and almost 2 m thickness. In terms of the mineralogical composition, it is composed of plagioclase (oligoclase, andesine) + pyroxene (augite, clinoenstatite) + opaque minerals and low amount of amphibole, biotite and quartz. Vitrofiric texture is dominant in upper level. Al2O3 content of the upper level from 12.75-13.96wt%, SiO2 66.70-68.10wt%, MgO 0.73-1.40wt%, Fe2O3 3.77-4.04wt%, TiO2 0.46-0.51wt%, CaO 1.97-2.91wt%, Na2O 3.41-4.29wt%, K2O 3.21-4.20wt%, P2O5 0.13-0.18wt% and LOI 3.65-4.52wt%. Geochemical analyze results reveal that Incesu ignimbrite has rhyolite, rhyodacite-dacite composition, medium to high-K calc-alkaline and peraluminous nature.Building stones can be classified according to their mineralogy, mechanical and physical properties and processing types. Mechanical and physical properties are more significant depending on the stones practice aim. The mean schmidt hardness value of the upper level of Incesu ignimbrite is 35, bulk density ranges between 2.42 - 2.66 g/cm3, mean water absorption by weight is 90%, mean point load strength is 38.2 MPa and failure load is 1890 kgf/cm based on the mechanical and physical test results.

CURRENT CONCEPTS ON THE GENETIC FACTORS IN ROTATOR CUFF PATHOLOGY AND FUTURE IMPLICATIONS FOR SPORTS PHYSICAL THERAPISTS

PubMed Central

Paré, Jessica; Froehlich, John E

2017-01-01

Context Recent advances within the field of genetics are currently changing many of the methodologies in which medicine is practiced. These advances are also beginning to influence the manner in which physical therapy services are rendered. Rotator cuff pathology is one of the most common diagnoses treated by the sports physical therapist. The purpose of this commentary is to educate sports physical therapists on the recent advances regarding how genetics influences rotator cuff pathology, including rotator cuff tears, and provide a perspective on how this information will likely influence post-operative shoulder rehabilitation in the near future. Evidence Acquisition A comprehensive review of the literature was completed using the Medline database along with individual searches of relevant physical therapy, surgical, cell biology, and sports medicine journals. Search terms included: shoulder, rotator cuff pathology, genetics, apoptosis, and physical therapy. Search results were compiled and evaluated; relevant primary studies and review articles were gathered; the results from this comprehensive review are summarized here. Study Design Clinical Commentary, Review of the Literature Results Recent advances within the understanding of rotator cuff pathology have further elucidated the cellular and molecular mechanisms associated with rotator cuff tears. There appears to be a hypoxic-induced apoptotic cellular pathway that contributes to rotator cuff tears. Activation of specific proteins termed matrix metalloproteinases appear to be involved in not only primary rotator cuff tears, but also may influence the re-tear rate after surgical intervention. Further advancements in the understanding of the cellular mechanisms contributing to rotator cuff tears and postoperative techniques to help prevent re-tears, may soon influence the methodology in which physical therapy services are provided to patients sustaining a rotator cuff injury. Conclusions At this time continued research is required to more fully develop a comprehensive understanding of the role of genetic variables both within primary rotator cuff tears and their influences on post-operative rehabilitation from rotator cuff repair surgery. Level of Evidence Level 5 PMID:28515982

Selected physical and mechanical properties of moso bamboo (Phyllostachys pubescens)

Treesearch

H.Q. Yu; Z.H. Jiang; C.Y. Hse; T.F. Shupe

2008-01-01

Selected physical and mechanical properties of moso bamboo (Phyllostachys pubescens). Selected physical and mechanical properties of 4?6 year old moso bamboo (Phyllostachys pubescens) grown in Zhejiang, China were investigated at different vertical and horizontal positions. Two way analysis of variance and Tukey?s mean comparison...

Cancer Pain: A Critical Review of Mechanism-based Classification and Physical Therapy Management in Palliative Care

PubMed Central

Kumar, Senthil P

2011-01-01

Mechanism-based classification and physical therapy management of pain is essential to effectively manage painful symptoms in patients attending palliative care. The objective of this review is to provide a detailed review of mechanism-based classification and physical therapy management of patients with cancer pain. Cancer pain can be classified based upon pain symptoms, pain mechanisms and pain syndromes. Classification based upon mechanisms not only addresses the underlying pathophysiology but also provides us with an understanding behind patient's symptoms and treatment responses. Existing evidence suggests that the five mechanisms – central sensitization, peripheral sensitization, sympathetically maintained pain, nociceptive and cognitive-affective – operate in patients with cancer pain. Summary of studies showing evidence for physical therapy treatment methods for cancer pain follows with suggested therapeutic implications. Effective palliative physical therapy care using a mechanism-based classification model should be tailored to suit each patient's findings, using a biopsychosocial model of pain. PMID:21976851

49 CFR Appendix B to Part 192 - Qualification of Pipe

Code of Federal Regulations, 2011 CFR

2011-10-01

... specification listed in section I of this appendix: (1) Physical (mechanical) properties of pipe, including...). II. Steel pipe of unknown or unlisted specification. A. Bending Properties. For pipe 2 inches (51... impair the strength or tightness of the pipe. D. Tensile Properties. If the tensile properties of the...

49 CFR Appendix B to Part 192 - Qualification of Pipe

Code of Federal Regulations, 2010 CFR

2010-10-01

... specification listed in section I of this appendix: (1) Physical (mechanical) properties of pipe, including...). II. Steel pipe of unknown or unlisted specification. A. Bending Properties. For pipe 2 inches (51... impair the strength or tightness of the pipe. D. Tensile Properties. If the tensile properties of the...

Upper-Division Student Difficulties with the Dirac Delta Function

ERIC Educational Resources Information Center

Wilcox, Bethany R.; Pollock, Steven J.

2015-01-01

The Dirac delta function is a standard mathematical tool that appears repeatedly in the undergraduate physics curriculum in multiple topical areas including electrostatics, and quantum mechanics. While Dirac delta functions are often introduced in order to simplify a problem mathematically, students still struggle to manipulate and interpret them.…

Testing the Fracture Behaviour of Chocolate

ERIC Educational Resources Information Center

Parsons, L. B.; Goodall, R.

2011-01-01

In teaching the materials science aspects of physics, mechanical behaviour is important due to its relevance to many practical applications. This article presents a method for experimentally examining the toughness of chocolate, including a design for a simple test rig, and a number of experiments that can be performed in the classroom. Typical…

7 CFR 205.206 - Crop pest, weed, and disease management practice standard.

Code of Federal Regulations, 2010 CFR

2010-01-01

... problems may be controlled through mechanical or physical methods including but not limited to: (1... problems may be controlled through: (1) Mulching with fully biodegradable materials; (2) Mowing; (3...) Plastic or other synthetic mulches: Provided, That, they are removed from the field at the end of the...

7 CFR 205.206 - Crop pest, weed, and disease management practice standard.

Code of Federal Regulations, 2011 CFR

2011-01-01

... problems may be controlled through mechanical or physical methods including but not limited to: (1... problems may be controlled through: (1) Mulching with fully biodegradable materials; (2) Mowing; (3...) Plastic or other synthetic mulches: Provided, That, they are removed from the field at the end of the...

Materials data handbook. Titanium 6Al-4V

NASA Technical Reports Server (NTRS)

Muraca, R. F.; Whittick, J. S.

1972-01-01

A summary of the materials property information for Titanium 6Al-4V alloy is presented. The scope of the information includes physical and mechanical properties at cryogenic, ambient, and elevated temperatures. Information on material procurement, metallurgy of the alloy, corrosion, environmental effects, fabrication, and bonding is developed.

NASA Tech Briefs, December 1998. Volume 22, No. 12

NASA Technical Reports Server (NTRS)

1998-01-01

Topics include: special coverage section on design and analysis software, and sections on electronic components and circuits, electronic systems, software, materials, mechanics, machinery/automation, manufacturing/fabrication, physical sciences, and special sections of Photonics Tech Briefs, Motion Control Tech briefs and a Hot Technology File 1999 Resource Guide.

NASA Tech Briefs, October 2000. Volume 24, No. 10

NASA Technical Reports Server (NTRS)

2000-01-01

Topics include: special coverage sections on CAD, CAE, and PDM, and, Composites and Plastics, and sections on electronic components and systems, software, test and measurement, mechanics, manufacturing/fabrication, physical sciences, information sciences, book and reports, and special sections of Electronics Tech Briefs and Motion Control Tech Briefs

Notes on Earth Atmospheric Entry for Mars Sample Return Missions

NASA Technical Reports Server (NTRS)

Rivell, Thomas

2006-01-01

The entry of sample return vehicles (SRVs) into the Earth's atmosphere is the subject of this document. The Earth entry environment for vehicles, or capsules, returning from the planet Mars is discussed along with the subjects of dynamics, aerodynamics, and heat transfer. The material presented is intended for engineers and scientists who do not have strong backgrounds in aerodynamics, aerothermodynamics and flight mechanics. The document is not intended to be comprehensive and some important topics are omitted. The topics considered in this document include basic principles of physics (fluid mechanics, dynamics and heat transfer), chemistry and engineering mechanics. These subjects include: a) fluid mechanics (aerodynamics, aerothermodynamics, compressible fluids, shock waves, boundary layers, and flow regimes from subsonic to hypervelocity; b) the Earth s atmosphere and gravity; c) thermal protection system design considerations; d) heat and mass transfer (convection, radiation, and ablation); e) flight mechanics (basic rigid body dynamics and stability); and f) flight- and ground-test requirements; and g) trajectory and flow simulation methods.

Woody Plant Invasion of Grassland: Lignin and Aliphatic Biopolymer Chemistry and Carbon Isotope Composition in Physical Fractions

NASA Astrophysics Data System (ADS)

Gamblin, D.; Boutton, T.; Liao, J.; Jastrow, J.; Filley, T.

2003-12-01

Significant changes in the apportionment of organic carbon in grassland and savanna soils have been document as a result of woody plant encroachment. In the Rio Grande Plains of Texas, C4 grasslands (d13C = -14 0/00) have undergone succession to trees and shrubs of a subtropical thorn woodland (d13C = -27 0/00) over the past 150 y which has resulted in increased soil organic carbon storage. Large differences in the turnover times of physical fractions in this system indicate selective preservation mechanisms which may include physical protection or inherent biochemical recalcitrance. To elucidate mechanisms of SOC sequestration during woody plant succession in this system, we are investigating the chemistry and compound-specific stable carbon isotope composition of lignin and aliphatic biopolymers in specific physical (size, density) soil fractions within a chronosequence that includes remnant grasslands (Time 0) and woody plant stands ranging in age from 10-130 y. The soil fraction data is being compared to biopolymer and isotope chemistry of the root, stem and/or leaf tissue of 20 of the dominant genus of plants in the system. Lignin phenols and suberin and cutin-derived hydroxyfatty acids are being isolated using alkaline CuO oxidation and tetramethylammonium hydroxide thermochemolysis. A comparison of the macroaggregate (greater than 250 um), microaggregate (53-250 um), and free silt and clay fractions in the oldest stand indicates that lignin is the most concentrated (organic carbon normalized values) in macroaggregates and is significantly less degraded, as determined by relative yields of oxidized and reduced lignin phenols. Additionally, the intra-aggregate silt and clay fraction from the macroaggregates contains less than half of the organic carbon normalized lignin phenols and is relatively more oxidized than what is found in the total macroaggregate pool. From these preliminary results it appears that the bulk macroaggregate pool contains the least degraded/freshest lignin of the physical fractions. This is consistent with the relatively shorter residence times determined for this fraction in this system. Continuing work includes compound specific isotope analysis of isolated lignin and hydroxyl fatty acids to elucidate biopolymer-specific turnover times which will provide important clues into the mechanisms of SOM storage and biopolymer recalcitrance.

Guide to Using Sierra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shaw, Ryan Phillip; Agelastos, Anthony Michael; Miller, Joel D.

2015-03-01

Sierra is an engineering mechanics simulation code suite supporting the Nation's Nuclear Weapons mission as well as other customers. It has explicit ties to Sandia National Labs' workfow, including geometry and meshing, design and optimization, and visualization. Dis- tinguishing strengths include "application aware" development, scalability, SQA and V&V, multiple scales, and multi-physics coupling. This document is intended to help new and existing users of Sierra as a user manual and troubleshooting guide.

Guide to Using Sierra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shaw, Ryan Phillip; Agelastos, Anthony Michael; Miller, Joel D.

2017-04-01

Sierra is an engineering mechanics simulation code suite supporting the Nation's Nuclear Weapons mission as well as other customers. It has explicit ties to Sandia National Labs' workfow, including geometry and meshing, design and optimization, and visualization. Dis- tinguishing strengths include "application aware" development, scalability, SQA and V&V, multiple scales, and multi-physics coupling. This document is intended to help new and existing users of Sierra as a user manual and troubleshooting guide.

Tell Me How to Do This Thing Called Design! Practical Application of Complexity Theory to Military Operations

DTIC Science & Technology

2011-04-08

into how economics, information theory and computer science, psychology, sociology, evolutionary biology, physics (quantum mechanics) and cosmology ...include knowledge and definition of “self” (as “self” is part of the environment) and the shared experience and perspective of others  That...including information, entropy, quantum behavior, and cosmological progress In short I assume the above and therefore my recommendations could be

Congenital Hydrocephalus.

PubMed

Estey, Chelsie M

2016-03-01

There are several types of hydrocephalus, which are characterized based on the location of the cerebrospinal fluid (CSF) accumulation. Physical features of animals with congenital hydrocephalus may include a dome-shaped skull, persistent fontanelle, and bilateral ventrolateral strabismus. Medical therapy involves decreasing the production of CSF. The most common surgical treatment is placement of a ventriculoperitoneal shunt. Postoperative complications may include infection, blockage, drainage abnormalities, and mechanical failure. Copyright © 2016 Elsevier Inc. All rights reserved.

Quantum and Multidimensional Explanations in a Neurobiological Context of Mind.

PubMed

Korf, Jakob

2015-08-01

This article examines the possible relevance of physical-mathematical multidimensional or quantum concepts aiming at understanding the (human) mind in a neurobiological context. Some typical features of the quantum and multidimensional concepts are briefly introduced, including entanglement, superposition, holonomic, and quantum field theories. Next, we consider neurobiological principles, such as the brain and its emerging (physical) mind, evolutionary and ontological origins, entropy, syntropy/neg-entropy, causation, and brain energy metabolism. In many biological processes, including biochemical conversions, protein folding, and sensory perception, the ubiquitous involvement of quantum mechanisms is well recognized. Quantum and multidimensional approaches might be expected to help describe and model both brain and mental processes, but an understanding of their direct involvement in mental activity, that is, without mediation by molecular processes, remains elusive. More work has to be done to bridge the gap between current neurobiological and physical-mathematical concepts with their associated quantum-mind theories. © The Author(s) 2014.

Physical properties of hydrate‐bearing sediments

USGS Publications Warehouse

Waite, William F.; Santamarina, J.C.; Cortes, D.D.; Dugan, Brandon; Espinoza, D.N.; Germaine, J.; Jang, J.; Jung, J.W.; Kneafsey, T.J.; Shin, H.; Soga, K.; Winters, William J.; Yun, T.S.

2009-01-01

Methane gas hydrates, crystalline inclusion compounds formed from methane and water, are found in marine continental margin and permafrost sediments worldwide. This article reviews the current understanding of phenomena involved in gas hydrate formation and the physical properties of hydrate‐bearing sediments. Formation phenomena include pore‐scale habit, solubility, spatial variability, and host sediment aggregate properties. Physical properties include thermal properties, permeability, electrical conductivity and permittivity, small‐strain elastic P and S wave velocities, shear strength, and volume changes resulting from hydrate dissociation. The magnitudes and interdependencies of these properties are critically important for predicting and quantifying macroscale responses of hydrate‐bearing sediments to changes in mechanical, thermal, or chemical boundary conditions. These predictions are vital for mitigating borehole, local, and regional slope stability hazards; optimizing recovery techniques for extracting methane from hydrate‐bearing sediments or sequestering carbon dioxide in gas hydrate; and evaluating the role of gas hydrate in the global carbon cycle.

Coupled Thermo-Mechanical and Photo-Chemical Degradation Mechanisms that determine the Reliability and Operational Lifetimes for CPV Technologies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dauskardt, Reinhold H.

This project sought to identify and characterize the coupled intrinsic photo-chemo-mechanical degradation mechanisms that determine the reliability and operational lifetimes for CPV technologies. Over a three year period, we have completed a highly successful program which has developed quantitative metrologies and detailed physics-based degradation models, providing new insight into the fundamental reliability physics necessary for improving materials, creating accelerated testing protocols, and producing more accurate lifetime predictions. The tasks for the program were separated into two focus areas shown in the figure below. Focus Area 1, led by Reinhold Dauskardt and Warren Cai with a primary collaboration with David Millermore » of NREL, studied the degradation mechanisms present in encapsulant materials. Focus Area 2, led by Reinhold Dauskardt and Ryan Brock with a primary collaboration with James Ermer and Peter Hebert of Spectrolab, studied stress development and degradation within internal CPV device interfaces. Each focus area was productive, leading to several publications, including findings on the degradation of silicone encapsulant under terrestrial UV, a model for photodegradation of silicone encapsulant adhesion, quantification and process tuning of antireflective layers on CPV, and discovery of a thermal cycling degradation mechanism present in metal gridline structures.« less

Cracks dynamics under tensional stress - a DEM approach

NASA Astrophysics Data System (ADS)

Debski, Wojciech; Klejment, Piotr; Kosmala, Alicja; Foltyn, Natalia; Szpindler, Maciej

2017-04-01

Breaking and fragmentation of solid materials is an extremely complex process involving scales ranging from an atomic scale (breaking inter-atomic bounds) up to thousands of kilometers in case of catastrophic earthquakes (in energy scale it ranges from single eV up to 1024 J). Such a large scale span of breaking processes opens lot of questions like, for example, scaling of breaking processes, existence of factors controlling final size of broken area, existence of precursors, dynamics of fragmentation, to name a few. The classical approach to study breaking process at seismological scales, i.e., physical processes in earthquake foci, is essentially based on two factors: seismic data (mostly) and the continuum mechanics (including the linear fracture mechanics). Such approach has been gratefully successful in developing kinematic (first) and dynamic (recently) models of seismic rupture and explaining many of earthquake features observed all around the globe. However, such approach will sooner or latter face a limitation due to a limited information content of seismic data and inherit limitations of the fracture mechanics principles. A way of avoiding this expected limitation is turning an attention towards a well established in physics method of computational simulations - a powerful branch of contemporary physics. In this presentation we discuss preliminary results of analysis of fracturing dynamics under external tensional forces using the Discrete Element Method approach. We demonstrate that even under a very simplified tensional conditions, the fragmentation dynamics is a very complex process, including multi-fracturing, spontaneous fracture generation and healing, etc. We also emphasis a role of material heterogeneity on the fragmentation process.

Bohm's Quantum Potential and the Visualization of Molecular Structure

NASA Technical Reports Server (NTRS)

Levit, Creon; Chancellor, Marisa K. (Technical Monitor)

1997-01-01

David Bohm's ontological interpretation of quantum theory can shed light on otherwise counter-intuitive quantum mechanical phenomena including chemical bonding. In the field of quantum chemistry, Richard Bader has shown that the topology of the Laplacian of the electronic charge density characterizes many features of molecular structure and reactivity. Visual and computational examination suggests that the Laplacian of Bader and the quantum potential of Bohm are morphologically equivalent. It appears that Bohmian mechanics and the quantum potential can make chemistry as clear as they makes physics.

Mário Schenberg: Physicist, politician and art critic

NASA Astrophysics Data System (ADS)

Guzzo, M. M.; Reggiani, N.

2015-12-01

Mário Schenberg is considered one of the greatest theoretical physicists of Brazil. He worked in different fields of physics including thermodynamics, quantum mechanics, statistical mechanics, general relativity, astrophysics and mathematics. He was assistant of the Ukrainian naturalized Italian physicist Gleb Wataghin and worked with prestigious physicists like as the Brazilians José Leite Lopes and César Lattes, the Russian-born American George Gamow and the Indian astrophysicist Subrahmanyan Chandrasekhar. Besides, he was also an active politician and critic of art.

Resource Letter SPE-1: Single-Photon Experiments in the Undergraduate Laboratory

NASA Astrophysics Data System (ADS)

Galvez, Enrique J.

2014-11-01

This Resource Letter lists undergraduate-laboratory adaptations of landmark optical experiments on the fundamentals of quantum physics. Journal articles and websites give technical details of the adaptations, which offer students unique hands-on access to testing fundamental concepts and predictions of quantum mechanics. A selection of the original research articles that led to the implementations is included. These developments have motivated a rethinking of the way quantum mechanics is taught, so this Resource Letter also lists textbooks that provide these new approaches.

Integrated orbital servicing study follow-on. Volume 2: Technical analysis and system design

NASA Technical Reports Server (NTRS)

1978-01-01

In-orbit service functional and physical requirements to support both low and high Earth orbit servicing/maintenance operations were defined, an optimum servicing system configuration was developed and mockups and early prototype hardware were fabricated to demonstrate and validate the concepts selected. Significant issues addressed include criteria for concept selection; representative mission equipment and approaches to their design for serviceability; significant serviceable spacecraft design aspects; servicer mechanism operation in one-g; approaches for the demonstration/simulation; and service mechanism structure design approach.

Mário Schenberg: Physicist, politician and art critic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guzzo, M. M., E-mail: guzzo@ifi.unicamp.br; Reggiani, N.

2015-12-17

Mário Schenberg is considered one of the greatest theoretical physicists of Brazil. He worked in different fields of physics including thermodynamics, quantum mechanics, statistical mechanics, general relativity, astrophysics and mathematics. He was assistant of the Ukrainian naturalized Italian physicist Gleb Wataghin and worked with prestigious physicists like as the Brazilians José Leite Lopes and César Lattes, the Russian-born American George Gamow and the Indian astrophysicist Subrahmanyan Chandrasekhar. Besides, he was also an active politician and critic of art.

Effects of Hygrothermal Cycling on the Chemical, Thermal, and Mechanical Properties of 862/W Epoxy Resin

NASA Technical Reports Server (NTRS)

Miller, Sandi G.; Roberts, Gary D.; Copa, Christine C.; Bail, Justin L.; Kohlman, Lee W.; Binienda, Wieslaw K.

2011-01-01

The hygrothermal aging characteristics of an epoxy resin were characterized over 1 year, which included 908 temperature and humidity cycles. The epoxy resin quickly showed evidence of aging through color change and increased brittleness. The influence of aging on the material s glass transition temperature (Tg) was evaluated by Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA). The Tg remained relatively constant throughout the year long cyclic aging profile. The chemical composition was monitored by Fourier Transform Infrared Spectroscopy (FTIR) where evidence of chemical aging and advancement of cure was noted. The tensile strength of the resin was tested as it aged. This property was severely affected by the aging process in the form of reduced ductility and embrittlement. Detailed chemical evaluation suggests many aging mechanisms are taking place during exposure to hygrothermal conditions. This paper details the influence of processes such as: advancement of cure, chemical degradation, and physical aging on the chemical and physical properties of the epoxy resin.

Role of exercise in maintaining the integrity of the neuromuscular junction.

PubMed

Nishimune, Hiroshi; Stanford, John A; Mori, Yasuo

2014-03-01

Physical activity plays an important role in preventing chronic disease in adults and the elderly. Exercise has beneficial effects on the nervous system, including at the neuromuscular junction (NMJ). Exercise causes hypertrophy of NMJs and improves recovery from peripheral nerve injuries, whereas decreased physical activity causes degenerative changes in NMJs. Recent studies have begun to elucidate molecular mechanisms underlying the beneficial effects of exercise. These mechanisms involve Bassoon, neuregulin-1, peroxisome proliferator-activated receptor gamma coactivator 1α, insulin-like growth factor-1, glial cell line-derived neurotrophic factor, neurotrophin 4, Homer, and nuclear factor of activated T cells c1. For example, NMJ denervation and active zone decreases have been observed in aged NMJs, but these age-dependent degenerative changes can be ameliorated by exercise. In this review we assess the effects of exercise on the maintenance and regeneration of NMJs and highlight recent insights into the molecular mechanisms underlying these exercise effects. Copyright © 2013 Wiley Periodicals, Inc.

Guest editorial: Special issue micro-and nanomachines.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanchez, Samuel; Paxton, Walter F.; Nitta, Takahiro

The articles in this special section focus on the technologies and applications supported by micro- and nanomachines. The world of artificial micro- and nanomachines has greatly expanded over the last few years to include a range of disciplines from chemistry, physics, biology, to micro/nanoengineering, robotics, and theoretical physics. The dream of engineering nanomachines involves fabricating devices that mimic the mechanical action of biological motors that operate over multiple length scales: from molecular-scale enzymes and motors such as kinesins to the micro-scale biomachinery responsible for the motility of tiny organisms such as the flagella motors of E. coli. However, the designmore » and fabrication of artificial nano- and micromachines with comparable performance as their biological counterparts is not a straightforward task. It requires a detailed understanding of the basic principles of the operation of biomotors and mechanisms that couple the dissipation of energy to mechanical motion. Furthermore, micro engineering and microfabrication knowledge is required in order to design efficient, small and even smart micro- and nanomachines.« less

Physical exercise prevents stress-induced activation of granule neurons and enhances local inhibitory mechanisms in the dentate gyrus.

PubMed

Schoenfeld, Timothy J; Rada, Pedro; Pieruzzini, Pedro R; Hsueh, Brian; Gould, Elizabeth

2013-05-01

Physical exercise is known to reduce anxiety. The ventral hippocampus has been linked to anxiety regulation but the effects of running on this subregion of the hippocampus have been incompletely explored. Here, we investigated the effects of cold water stress on the hippocampus of sedentary and runner mice and found that while stress increases expression of the protein products of the immediate early genes c-fos and arc in new and mature granule neurons in sedentary mice, it has no such effect in runners. We further showed that running enhances local inhibitory mechanisms in the hippocampus, including increases in stress-induced activation of hippocampal interneurons, expression of vesicular GABA transporter (vGAT), and extracellular GABA release during cold water swim stress. Finally, blocking GABAA receptors in the ventral hippocampus, but not the dorsal hippocampus, with the antagonist bicuculline, reverses the anxiolytic effect of running. Together, these results suggest that running improves anxiety regulation by engaging local inhibitory mechanisms in the ventral hippocampus.

Physically-Induced Cytoskeleton Remodeling of Cells in Three-Dimensional Culture

PubMed Central

Lee, Sheng-Lin; Nekouzadeh, Ali; Butler, Boyd; Pryse, Kenneth M.; McConnaughey, William B.; Nathan, Adam C.; Legant, Wesley R.; Schaefer, Pascal M.; Pless, Robert B.

2012-01-01

Characterizing how cells in three-dimensional (3D) environments or natural tissues respond to biophysical stimuli is a longstanding challenge in biology and tissue engineering. We demonstrate a strategy to monitor morphological and mechanical responses of contractile fibroblasts in a 3D environment. Cells responded to stretch through specific, cell-wide mechanisms involving staged retraction and reinforcement. Retraction responses occurred for all orientations of stress fibers and cellular protrusions relative to the stretch direction, while reinforcement responses, including extension of cellular processes and stress fiber formation, occurred predominantly in the stretch direction. A previously unreported role of F-actin clumps was observed, with clumps possibly acting as F-actin reservoirs for retraction and reinforcement responses during stretch. Responses were consistent with a model of cellular sensitivity to local physical cues. These findings suggest mechanisms for global actin cytoskeleton remodeling in non-muscle cells and provide insight into cellular responses important in pathologies such as fibrosis and hypertension. PMID:23300512

Guest editorial: Special issue micro-and nanomachines.

DOE PAGES

Sanchez, Samuel; Paxton, Walter F.; Nitta, Takahiro

2015-04-01

The articles in this special section focus on the technologies and applications supported by micro- and nanomachines. The world of artificial micro- and nanomachines has greatly expanded over the last few years to include a range of disciplines from chemistry, physics, biology, to micro/nanoengineering, robotics, and theoretical physics. The dream of engineering nanomachines involves fabricating devices that mimic the mechanical action of biological motors that operate over multiple length scales: from molecular-scale enzymes and motors such as kinesins to the micro-scale biomachinery responsible for the motility of tiny organisms such as the flagella motors of E. coli. However, the designmore » and fabrication of artificial nano- and micromachines with comparable performance as their biological counterparts is not a straightforward task. It requires a detailed understanding of the basic principles of the operation of biomotors and mechanisms that couple the dissipation of energy to mechanical motion. Furthermore, micro engineering and microfabrication knowledge is required in order to design efficient, small and even smart micro- and nanomachines.« less

Consistent Quantum Theory

NASA Astrophysics Data System (ADS)

Griffiths, Robert B.

2001-11-01

Quantum mechanics is one of the most fundamental yet difficult subjects in physics. Nonrelativistic quantum theory is presented here in a clear and systematic fashion, integrating Born's probabilistic interpretation with Schrödinger dynamics. Basic quantum principles are illustrated with simple examples requiring no mathematics beyond linear algebra and elementary probability theory. The quantum measurement process is consistently analyzed using fundamental quantum principles without referring to measurement. These same principles are used to resolve several of the paradoxes that have long perplexed physicists, including the double slit and Schrödinger's cat. The consistent histories formalism used here was first introduced by the author, and extended by M. Gell-Mann, J. Hartle and R. Omnès. Essential for researchers yet accessible to advanced undergraduate students in physics, chemistry, mathematics, and computer science, this book is supplementary to standard textbooks. It will also be of interest to physicists and philosophers working on the foundations of quantum mechanics. Comprehensive account Written by one of the main figures in the field Paperback edition of successful work on philosophy of quantum mechanics

Conquering the Physics GRE

NASA Astrophysics Data System (ADS)

Kahn, Yoni; Anderson, Adam

2018-03-01

Preface; How to use this book; Resources; 1. Classical mechanics; 2. Electricity and magnetism; 3. Optics and waves; 4. Thermodynamics and statistical mechanics; 5. Quantum mechanics and atomic physics; 6. Special relativity; 7. Laboratory methods; 8. Specialized topics; 9. Special tips and tricks for the Physics GRE; Sample exams and solutions; References; Equation index; Subject index; Problems index.

The Non-Signalling theorem in generalizations of Bell's theorem

NASA Astrophysics Data System (ADS)

Walleczek, J.; Grössing, G.

2014-04-01

Does "epistemic non-signalling" ensure the peaceful coexistence of special relativity and quantum nonlocality? The possibility of an affirmative answer is of great importance to deterministic approaches to quantum mechanics given recent developments towards generalizations of Bell's theorem. By generalizations of Bell's theorem we here mean efforts that seek to demonstrate the impossibility of any deterministic theories to obey the predictions of Bell's theorem, including not only local hidden-variables theories (LHVTs) but, critically, of nonlocal hidden-variables theories (NHVTs) also, such as de Broglie-Bohm theory. Naturally, in light of the well-established experimental findings from quantum physics, whether or not a deterministic approach to quantum mechanics, including an emergent quantum mechanics, is logically possible, depends on compatibility with the predictions of Bell's theorem. With respect to deterministic NHVTs, recent attempts to generalize Bell's theorem have claimed the impossibility of any such approaches to quantum mechanics. The present work offers arguments showing why such efforts towards generalization may fall short of their stated goal. In particular, we challenge the validity of the use of the non-signalling theorem as a conclusive argument in favor of the existence of free randomness, and therefore reject the use of the non-signalling theorem as an argument against the logical possibility of deterministic approaches. We here offer two distinct counter-arguments in support of the possibility of deterministic NHVTs: one argument exposes the circularity of the reasoning which is employed in recent claims, and a second argument is based on the inconclusive metaphysical status of the non-signalling theorem itself. We proceed by presenting an entirely informal treatment of key physical and metaphysical assumptions, and of their interrelationship, in attempts seeking to generalize Bell's theorem on the basis of an ontic, foundational interpretation of the non-signalling theorem. We here argue that the non-signalling theorem must instead be viewed as an epistemic, operational theorem i.e. one that refers exclusively to what epistemic agents can, or rather cannot, do. That is, we emphasize that the non-signalling theorem is a theorem about the operational inability of epistemic agents to signal information. In other words, as a proper principle, the non-signalling theorem may only be employed as an epistemic, phenomenological, or operational principle. Critically, our argument emphasizes that the non-signalling principle must not be used as an ontic principle about physical reality as such, i.e. as a theorem about the nature of physical reality independently of epistemic agents e.g. human observers. One major reason in favor of our conclusion is that any definition of signalling or of non-signalling invariably requires a reference to epistemic agents, and what these agents can actually measure and report. Otherwise, the non-signalling theorem would equal a general "no-influence" theorem. In conclusion, under the assumption that the non-signalling theorem is epistemic (i.e. "epistemic non-signalling"), the search for deterministic approaches to quantum mechanics, including NHVTs and an emergent quantum mechanics, continues to be a viable research program towards disclosing the foundations of physical reality at its smallest dimensions.

We Never See Children in Parks: A Qualitative Examination of the Role of Safety Concerns on Physical Activity Among Children.

PubMed

Rader, Nicole E; Byrd, Sylvia H; Fountain, Brent J; Bounds, Christopher W; Gray, Virginia; Frugé, Andrew Dandridge

2015-07-01

Previous literature indicates physical activity and obesity are interrelated problems, especially among children in disorganized environments. Qualitative focus groups were conducted with parents of elementary school children located within the Mississippi Delta to answer one overarching research question: "What influence do safety concerns have on physical activity for children in the Mississippi Delta?" There were 2 large themes; first was that recreational areas were criminal and the second was that safety concerns were a barrier to physical activity. Safety concerns as a barrier to physical activity rendered 3 sub-themes, including 1) Parental fear of crime inhibited the use of public recreational spaces, 2) Parental perceptions of police as ineffective and untrustworthy reduced the use of public spaces where children might play, and 3) Parents often expressed safety-induced intense supervision requirements that limited the physical activity of their children. Our study provides valuable insights into the mechanisms by which safety concerns limit physical activity of children in the Mississippi Delta.

Physical Activity, Biomarkers, and Disease Outcomes in Cancer Survivors: A Systematic Review

PubMed Central

Friedenreich, Christine M.; Courneya, Kerry S.; Siddiqi, Sameer M.; McTiernan, Anne; Alfano, Catherine M.

2012-01-01

Background Cancer survivors often seek information about how lifestyle factors, such as physical activity, may influence their prognosis. We systematically reviewed studies that examined relationships between physical activity and mortality (cancer-specific and all-cause) and/or cancer biomarkers. Methods We identified 45 articles published from January 1950 to August 2011 through MEDLINE database searches that were related to physical activity, cancer survival, and biomarkers potentially relevant to cancer survival. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement to guide this review. Study characteristics, mortality outcomes, and biomarker-relevant and subgroup results were abstracted for each article that met the inclusion criteria (ie, research articles that included participants with a cancer diagnosis, mortality outcomes, and an assessment of physical activity). Results There was consistent evidence from 27 observational studies that physical activity is associated with reduced all-cause, breast cancer–specific, and colon cancer–specific mortality. There is currently insufficient evidence regarding the association between physical activity and mortality for survivors of other cancers. Randomized controlled trials of exercise that included biomarker endpoints suggest that exercise may result in beneficial changes in the circulating level of insulin, insulin-related pathways, inflammation, and, possibly, immunity; however, the evidence is still preliminary. Conclusions Future research directions identified include the need for more observational studies on additional types of cancer with larger sample sizes; the need to examine whether the association between physical activity and mortality varies by tumor, clinical, or risk factor characteristics; and the need for research on the biological mechanisms involved in the association between physical activity and survival after a cancer diagnosis. Future randomized controlled trials of exercise with biomarker and cancer-specific disease endpoints, such as recurrence, new primary cancers, and cancer-specific mortality in cancer survivors, are warranted. PMID:22570317

A review of the outcome expectancy construct in physical activity research.

PubMed

Williams, David M; Anderson, Eileen S; Winett, Richard A

2005-02-01

Outcome expectancy is a central construct in social cognitive models of health behavior widely used as frameworks for physical activity research. This article provides a review of the outcome expectancy construct and its application to research on physical activity. Theoretical articles describing definitions and placement of outcome expectancy within social cognitive models, as well as empirical research on outcome expectancy and physical activity, were reviewed. Self-efficacy theory, the transtheoretical model, the theory of planned behavior, and protection motivation theory differ in their labeling and conceptualization of outcome expectancy but unanimously include expected outcomes of behavior. Preliminary empirical investigation of the role of outcome expectancy in understanding physical activity has yielded mixed results. Positive outcome expectancy appears to be more predictive of physical activity in older adults than in young to middle-aged adults, and personal barriers appear to be the most predictive subtype of negative outcome expectancy. In addition, a small number of studies indicate relations between outcome expectancy and other theoretical variables, including behavioral intention, stage of change, and self-efficacy. Further research on the role of outcome expectancy is necessary to design effective physical activity interventions. New directions in outcome expectancy research could involve (a) expanding the conceptualization of outcome expectancy to include expected outcomes of sedentary behavior and affective responses to physical activity, (b) further examination of potential moderators of the relation between outcome expectancy and physical activity (such as outcome value and outcome proximity), (c) distinguishing between the role of outcome expectancy in behavior onset versus behavior maintenance, (d) examining outcome expectancy as a mechanism of change in environmental intervention approaches, and (e) further analysis of interrelations between outcome expectancy and other social cognitive variables.

Mechanics and Physics of Solids, Uncertainy, and the Archetype-Genome Exemplar

NASA Astrophysics Data System (ADS)

Greene, M. Steven

This dissertation argues that the mechanics and physics of solids rely on a fundamental exemplar: the apparent properties of a system depend on the building blocks that comprise it. Building blocks are referred to as archetypes and apparent system properties as the system genome. Three entities are of importance: the archetype properties, the conformation of archetypes, and the properties of interactions activated by that conformation. The combination of these entities into the system genome is called assembly. To show the utility of the archetype-genome exemplar, the dissertation presents the mathematical construction and computational implementation of a new theory for solid mechanics that is a continuum manifestation of the assembly process. The so-called archetype-blending continuum theory aligns the form of globally valid balance laws with physics evolving in a material's composite constitutive response so that, by rethinking conventional micromechanics, the theory accounts naturally for each piece of the genome assembly triplet: archetypes, interactions, and their conformation. With the pieces of the triplet isolated in the theory, materials genome design concepts that separately control microstructure and property may be gleaned from exploration of the constitutive parameter space. A suite of simulations that apply the new theory to polymer nanocomposite materials demonstrate the ability of the theory to predict a robust material genome that includes damping properties, modulus weakening, local strain amplification, and size effects. The dissertation also presents a theoretical assessment of the importance of uncertainty propagation in the archetype-genome exemplar. The findings from a set of computational experiments on instances of a general class of microstructured materials suggest that when overlap occurs between the size of the system geometry and the features of the conformation, material genomes become less certain. Increasing nonuniformity of boundary conditions and the size of random field correlation lengths exacerbate this conclusion. These criteria are combined into a scalar metric used to assess the impact of archetype-level uncertainties on the material genome for general scenarios in solid mechanics. Exemplary benchmark problems include bending in elastoplasticity and instability-induced pattern transition in porous elastomer. The contributions of this dissertation are threefold: (1) the mathematical construction of a new continuum theory for mechanics and physics of solids, (2) implementation of the theory, and (3) theoretical assessment of the scenarios in which material genomes deviate from determinism.

Baseball Physics: A New Mechanics Lab

ERIC Educational Resources Information Center

Wagoner, Kasey; Flanagan, Daniel

2018-01-01

The game of baseball provides an interesting laboratory for experimenting with mechanical phenomena (there are many good examples in "The Physics Teacher," available on Professor Alan Nathan's website, and discussed in "Physics of Baseball & Softball"). We have developed a lab, for an introductory-level physics course, that…

True-slime-mould-inspired hydrostatically coupled oscillator system exhibiting versatile behaviours.

PubMed

Umedachi, Takuya; Idei, Ryo; Ito, Kentaro; Ishiguro, Akio

2013-09-01

Behavioural diversity is an indispensable attribute of living systems, which makes them intrinsically adaptive and responsive to the demands of a dynamically changing environment. In contrast, conventional engineering approaches struggle to suppress behavioural diversity in artificial systems to reach optimal performance in given environments for desired tasks. The goals of this research include understanding the essential mechanism that endows living systems with behavioural diversity and implementing the mechanism in robots to exhibit adaptive behaviours. For this purpose, we have focused on an amoeba-like unicellular organism: the plasmodium of true slime mould. Despite the absence of a central nervous system, the plasmodium exhibits versatile spatiotemporal oscillatory patterns and switches spontaneously among these patterns. By exploiting this behavioural diversity, it is able to exhibit adaptive behaviour according to the situation encountered. Inspired by this organism, we built a real physical robot using hydrostatically coupled oscillators that produce versatile oscillatory patterns and spontaneous transitions among the patterns. The experimental results show that exploiting physical hydrostatic interplay—the physical dynamics of the robot—allows simple phase oscillators to promote versatile behaviours. The results can contribute to an understanding of how a living system generates versatile and adaptive behaviours with physical interplays among body parts.

Evidence for sex differences in cardiovascular aging and adaptive responses to physical activity.

PubMed

Parker, Beth A; Kalasky, Martha J; Proctor, David N

2010-09-01

There are considerable data addressing sex-related differences in cardiovascular system aging and disease risk/progression. Sex differences in cardiovascular aging are evident during resting conditions, exercise, and other acute physiological challenges (e.g., orthostasis). In conjunction with these sex-related differences-or perhaps even as an underlying cause-the impact of cardiorespiratory fitness and/or physical activity on the aging cardiovascular system also appears to be sex-specific. Potential mechanisms contributing to sex-related differences in cardiovascular aging and adaptability include changes in sex hormones with age as well as sex differences in baseline fitness and the dose of activity needed to elicit cardiovascular adaptations. The purpose of the present paper is thus to review the primary research regarding sex-specific plasticity of the cardiovascular system to fitness and physical activity in older adults. Specifically, the paper will (1) briefly review known sex differences in cardiovascular aging, (2) detail emerging evidence regarding observed cardiovascular outcomes in investigations of exercise and physical activity in older men versus women, (3) explore mechanisms underlying the differing adaptations to exercise and habitual activity in men versus women, and (4) discuss implications of these findings with respect to chronic disease risk and exercise prescription.