WorldWideScience

Sample records for biointeractive physical size

  1. Biointeractions of ultrasmall glutathione-coated gold nanoparticles: effect of small size variations

    Science.gov (United States)

    Sousa, Alioscka A.; Hassan, Sergio A.; Knittel, Luiza L.; Balbo, Andrea; Aronova, Maria A.; Brown, Patrick H.; Schuck, Peter; Leapman, Richard D.

    2016-03-01

    Recent in vivo studies have established ultrasmall (nanomedicine. However, systematic in vitro investigations to gain a more fundamental understanding of the particles' biointeractions are still lacking. Herein we examined the behavior of ultrasmall AuGSH in vitro, focusing on their ability to resist aggregation and adsorption from serum proteins. Despite having net negative charge, AuGSH particles were colloidally stable in biological media and able to resist binding from serum proteins, in agreement with the favorable bioresponses reported for AuGSH in vivo. However, our results revealed disparate behaviors depending on nanoparticle size: particles between 2 and 3 nm in core diameter were found to readily aggregate in biological media, whereas those strictly under 2 nm were exceptionally stable. Molecular dynamics simulations provided microscopic insight into interparticle interactions leading to aggregation and their sensitivity to the solution composition and particle size. These results have important implications, in that seemingly small variations in size can impact the biointeractions of ultrasmall AuGSH, and potentially of other ultrasmall nanoparticles as well.Recent in vivo studies have established ultrasmall (nanomedicine. However, systematic in vitro investigations to gain a more fundamental understanding of the particles' biointeractions are still lacking. Herein we examined the behavior of ultrasmall AuGSH in vitro, focusing on their ability to resist aggregation and adsorption from serum proteins. Despite having net negative charge, AuGSH particles were colloidally stable in biological media and able to resist binding from serum proteins, in agreement with the favorable bioresponses reported for AuGSH in vivo. However, our results revealed disparate behaviors depending on nanoparticle size: particles between 2 and 3 nm in core diameter were found to readily aggregate in biological media, whereas those strictly under 2 nm were exceptionally stable

  2. Biointeractions of ultrasmall glutathione-coated gold nanoparticles: effect of small size variations

    Science.gov (United States)

    Sousa, Alioscka A.; Hassan, Sergio A.; Knittel, Luiza L.; Balbo, Andrea; Aronova, Maria A.; Brown, Patrick H.; Schuck, Peter; Leapman, Richard D.

    2016-03-01

    Recent in vivo studies have established ultrasmall (platform for applications in nanomedicine. However, systematic in vitro investigations to gain a more fundamental understanding of the particles' biointeractions are still lacking. Herein we examined the behavior of ultrasmall AuGSH in vitro, focusing on their ability to resist aggregation and adsorption from serum proteins. Despite having net negative charge, AuGSH particles were colloidally stable in biological media and able to resist binding from serum proteins, in agreement with the favorable bioresponses reported for AuGSH in vivo. However, our results revealed disparate behaviors depending on nanoparticle size: particles between 2 and 3 nm in core diameter were found to readily aggregate in biological media, whereas those strictly under 2 nm were exceptionally stable. Molecular dynamics simulations provided microscopic insight into interparticle interactions leading to aggregation and their sensitivity to the solution composition and particle size. These results have important implications, in that seemingly small variations in size can impact the biointeractions of ultrasmall AuGSH, and potentially of other ultrasmall nanoparticles as well.Recent in vivo studies have established ultrasmall (platform for applications in nanomedicine. However, systematic in vitro investigations to gain a more fundamental understanding of the particles' biointeractions are still lacking. Herein we examined the behavior of ultrasmall AuGSH in vitro, focusing on their ability to resist aggregation and adsorption from serum proteins. Despite having net negative charge, AuGSH particles were colloidally stable in biological media and able to resist binding from serum proteins, in agreement with the favorable bioresponses reported for AuGSH in vivo. However, our results revealed disparate behaviors depending on nanoparticle size: particles between 2 and 3 nm in core diameter were found to readily aggregate in biological media

  3. In Vitro Screening of the Apatite-Forming Ability, Biointeractivity and Physical Properties of a Tricalcium Silicate Material for Endodontics and Restorative Dentistry

    OpenAIRE

    Maria Giovanna Gandolfi; Francesco Siboni; Antonella Polimeni; Maurizio Bossù; Francesco Riccitiello; Sandro Rengo; Carlo Prati

    2013-01-01

    Aim: Calcium silicate-based materials are hydraulic self-setting materials with physico-chemical properties suitable for endodontic surgery and good biological/clinical outcomes. The study aim was to evaluate the bio-properties (biointeractivity and apatite-forming ability) and selected physical properties (porosity, water sorption, solubility, and setting time) of Biodentine, a tricalcium silicate material for endodontics and restorative dentistry, compared to that of ProRoot MTA (Mineral ...

  4. In Vitro Screening of the Apatite-Forming Ability, Biointeractivity and Physical Properties of a Tricalcium Silicate Material for Endodontics and Restorative Dentistry

    Directory of Open Access Journals (Sweden)

    Maria Giovanna Gandolfi

    2013-12-01

    Full Text Available Aim: Calcium silicate-based materials are hydraulic self-setting materials with physico-chemical properties suitable for endodontic surgery and good biological/clinical outcomes. The study aim was to evaluate the bio-properties (biointeractivity and apatite-forming ability and selected physical properties (porosity, water sorption, solubility, and setting time of Biodentine, a tricalcium silicate material for endodontics and restorative dentistry, compared to that of ProRoot MTA (Mineral Trioxide Aggregate as gold standard material. Methods: Biodentine and ProRoot MTA pastes were prepared and analyzed for calcium release and alkalinizing activity (3 h–28 days, setting time, water sorption, porosity, solubility, surface microstructure and composition, and apatite-forming ability in simulated body fluid. Results: Biodentine showed higher calcium release, alkalinizing activity, and solubility but higher open and apparent porosity, water sorption, and a markedly shorter setting time. Calcium phosphate (CaP deposits were noted on material surfaces after short ageing times. A CaP coating composed of spherulites was detected after 28 days. The thickness, continuity, and Ca/P ratio of the coating differed markedly between the materials. Biodentine showed a coating composed by denser but smaller spherulites, while ProRoot MTA showed large but less dense aggregates of spherulitic deposits. Conclusions: Biodentine showed a pronounced ability to release calcium and extended alkalinizing activity interlinked with its noticeable porosity, water sorption, and solubility: open porosities provide a broad wet biointeractive surface for the release of the calcium and hydroxyl ions involved in the formation of a CaP mineral. Biodentine is a biointeractive tricalcium silicate material with interesting chemical-physical properties and represents a fast-setting alternative to the conventional calcium silicate MTA-like cements.

  5. Assessing Learning in Small Sized Physics Courses

    CERN Document Server

    Ene, Emanuela

    2015-01-01

    We describe the construction, validation and testing of a concept inventory for an Introduction to Physics of Semiconductors course offered by the department of physics for undergraduate engineering students. By design, this inventory addresses both content knowledge and ability to interpret content via different cognitive processes described in Bloom's taxonomy. The primary challenge comes from the low number of test takers. Since the Rasch Model (aka 1PL IRT model), can be used with small sample sizes, we describe Rasch Modeling analysis and results for this concept inventory.

  6. Buoyant Nanoparticles: Implications for Nano-Biointeractions in Cellular Studies.

    Science.gov (United States)

    Watson, C Y; DeLoid, G M; Pal, A; Demokritou, P

    2016-06-01

    In the safety and efficacy assessment of novel nanomaterials, the role of nanoparticle (NP) kinetics in in vitro studies is often ignored although it has significant implications in dosimetry, hazard ranking, and nanomedicine efficacy. It is demonstrated here that certain nanoparticles are buoyant due to low effective densities of their formed agglomerates in culture media, which alters particle transport and deposition, dose-response relationships, and underestimates toxicity and bioactivity. To investigate this phenomenon, this study determines the size distribution, effective density, and assesses fate and transport for a test buoyant NP (polypropylene). To enable accurate dose-response assessment, an inverted 96-well cell culture platform is developed in which adherent cells are incubated above the buoyant particle suspension. The effect of buoyancy is assessed by comparing dose-toxicity responses in human macrophages after 24 h incubation in conventional and inverted culture systems. In the conventional culture system, no adverse effects are observed at any NP concentration tested (up to 250 μg mL(-1) ), whereas dose-dependent decreases in viability and increases in reactive oxygen species are observed in the inverted system. This work sheds light on an unknown issue that plays a significant role in vitro hazard screening and proposes a standardized methodology for buoyant NP assessments. PMID:27135209

  7. Physics-Based Reactive Burn Model: Grain Size Effects

    Science.gov (United States)

    Lu, X.; Hamate, Y.; Horie, Y.

    2007-12-01

    We have been developing a physics-based reactive burn (PBRB) model, which was formulated based on the concept of a statistical hot spot cell. In the model, essential thermomechanics and physiochemical features are explicitly modeled. In this paper, we have extended the statistical hot spot model to explicitly describe the ignition and growth of hot spots. In particular, grain size effects are explicitly delineated through introduction of grain size-dependent, thickness of the hot-region, energy deposition criterion, and specific surface area. Besides the linear relationships between the run distance to detonation and the critical diameter with respect to the reciprocal specific surface area of heterogeneous explosives (HE), which is based on the original model and discussed in a parallel paper of this meeting, parametric studies have shown that the extended PBRB model can predict a non-monotonic variation of shock sensitivity with grain size, as observed by Moulard et al.

  8. IN MY OPINION: What about person-sized physics?

    Science.gov (United States)

    Cornwall, Malcolm

    1999-03-01

    physics undergraduate - that it is fundamentally important in our everyday lives. It is `person-sized physics' (give or take a factor of 1010!) which lies behind the numerous items that make up our world today, among them PCs, mobile phones, video CDs, `intelligent' materials and the multifarious means for medical imaging. Can't we promote an interest in physics through popular books and articles on wonders such as these? Yes, such books do exist, but on the bookshop shelves you will find scant representation of this type of physics among the well-written and superbly presented `pop' books like those of Hawking, Gribbin and Davies. Until recently I was a Deputy Editor of this journal. During the past few years we have published numerous `special issues' focusing on a specific topic. Those I have edited have reflected my philosophy, and have included issues on Laser Applications, Energy Update, and the Physics of the Body. Other editors have produced equally `applied' special issues. Might youngsters (or even an oldster) be equally excited by the elucidation of the mysteries of the quantum world in the context of, say, the silicon chip as by the world of the fundamental particle? Surely the glamour of physics-based state-of-the-art recording technology or the latest PC or sleek new aircraft or medical imaging technique can compete with the `wonders of space and time' exhaustively recycled in the popular literature? Come on popular science authors! Try your hand at dressing up the physics of everyday life so that the excitement and immediate relevance of physics is displayed before the people - not least, the young people - in the street.

  9. Physical size associations to offensive performance among major league leaders.

    Science.gov (United States)

    Crotin, Ryan L; Forsythe, Charles M; Karakolis, Thomas; Bhan, Shivam

    2014-09-01

    Minimal work has studied physical size effects on statistical performance among Major League players. In this study, longitudinal, bivariate, and regression analyses studied the impact of physical size on offensive baseball statistics within a homogeneous talent sample of Major League batting leaders. Body mass index (BMI) was calculated from heights and weights that were publicly available to form a statistical database of 4,360 offense leaders from 1950 to 2010. Repeated-measures analysis of variances examined differences in anthropometrics and baseball statistics between each decade from 1950 to 2010. Bivariate correlation and linear regression analyses evaluated BMI as an independent variable of influence, where all tests applied an a priori significance level (p ≤ 0.05). After 1980, offensive performance increased (p ≤ 0.05) concurrent to body mass and BMI growth (p statistically decreased (p ≤ 0.05). All baseball statistics were positively correlated and predicted by BMI (p statistics. Over the 60-year period, greater body weight-to-height proportions owed to improved competitive performance, which suggests greater emphasis on hypertrophic stimuli in training and nutrition, as well as selection of larger professional baseball prospects. PMID:24875425

  10. Discriminating Between the Physical Processes that Drive Spheroid Size Evolution

    CERN Document Server

    Hopkins, Philip F; Hernquist, Lars; Wuyts, Stijn; Cox, Thomas J

    2009-01-01

    Massive galaxies at high-z have smaller effective radii than those today, but similar central densities. Their size growth therefore relates primarily to the evolving abundance of low-density material. Various models have been proposed to explain this evolution, which have different implications for galaxy, star, and BH formation. We compile observations of spheroid properties as a function of redshift and use them to test proposed models. Evolution in progenitor gas-richness with redshift gives rise to initial formation of smaller spheroids at high-z. These systems can then evolve in apparent or physical size via several channels: (1) equal-density 'dry' mergers, (2) later major or minor 'dry' mergers with less-dense galaxies, (3) adiabatic expansion, (4) evolution in stellar populations & mass-to-light-ratio gradients, (5) age-dependent bias in stellar mass estimators, (6) observational fitting/selection effects. If any one of these is tuned to explain observed size evolution, they make distinct predict...

  11. Physics of sinking and selection of plankton cell size

    Energy Technology Data Exchange (ETDEWEB)

    Sciascia, R., E-mail: r.sciascia@isac.cnr.it [Institute of Atmospheric Sciences and Climate, CNR, Corso Fiume, 4, 10133 Torino (Italy); Doctorate Program in Fluid Dynamics, Politecnico di Torino (Italy); De Monte, S. [CNRS, UMR 7625 “Ecologie et Evolution”, Paris, F-75005 (France); Université Pierre et Marie Curie-Paris 6, UMR 7625 “Ecologie et Evolution”, Paris, F-75005 (France); Institut de Biologie de l' Ecole Normale Supérieure, UMR 7625 “Ecologie et Evolution”, Paris, F-75005 (France); Provenzale, A. [Institute of Atmospheric Sciences and Climate, CNR, Corso Fiume, 4, 10133 Torino (Italy)

    2013-02-04

    Gravitational sinking in the water column is known to affect size composition of planktonic communities. One important driver toward the reduction of plankton size is the fact that larger cells tend to sink faster below the euphotic layer. In this work, we discuss the role of gravitational sinking in driving cell size selection, showing that the outcome of phytoplankton competition is determined by the dependence of sinking velocity on cell size, shape, and on the temporal variability associated with turbulence. This opens a question on whether regional modulations of the turbulence intensity could affect size distribution of planktonic communities.

  12. Effect of four different size reduction methods on the particle size, solubility enhancement and physical stability of nicergoline nanocrystals.

    Science.gov (United States)

    Martena, Valentina; Shegokar, Ranjita; Di Martino, Piera; Müller, Rainer H

    2014-09-01

    Nicergoline, a poorly soluble active pharmaceutical ingredient, possesses vaso-active properties which causes peripheral and central vasodilatation. In this study, nanocrystals of nicergoline were prepared in an aqueous solution of polysorbate 80 (nanosuspension) by using four different laboratory scale size reduction techniques: high pressure homogenization (HPH), bead milling (BM) and combination techniques (high pressure homogenization followed by bead milling HPH + BM, and bead milling followed by high pressure homogenization BM + HPH). Nanocrystals were investigated regarding to their mean particles size, zeta potential and particle dissolution. A short term physical stability study on nanocrystals stored at three different temperatures (4, 20 and 40 °C) was performed to evaluate the tendency to change in particle size, aggregation and zeta potential. The size reduction technique and the process parameters like milling time, number of homogenization cycles and pressure greatly affected the size of nanocrystals. Among the techniques used, the combination techniques showed superior and consistent particle size reduction compared to the other two methods, HPH + BM and BM + HPH giving nanocrystals of a mean particle size of 260 and 353 nm, respectively. The particle dissolution was increased for any nanocrystals samples, but it was particularly increased by HPH and combination techniques. Independently to the production method, nicergoline nanocrystals showed slight increase in particle size over the time, but remained below 500 nm at 20 °C and refrigeration conditions. PMID:23815299

  13. Physical mechanism of the linear beam-size effect at colliders

    Energy Technology Data Exchange (ETDEWEB)

    Melnikov, K. [Institut fuer Physik, THEP, Johannes Gutenberg Universitaet, Staudinger weg 7, D 55099 Mainz (Germany); Kotkin, G.L.; Serbo, V.G. [Novosibirsk State University, 630090, Novosibirsk (Russia)

    1996-09-01

    We present a qualitative but precise description of the linear beam-size effect predicted for the processes in which unstable but long-living particles collide with each other. We derive a physically pronounced equation for the event rate which proves that the linear beam-size effect corresponds to the scattering of one beam of particles on the decay products of the other. We compare this linear beam-size effect with the known logarithmic beam-size effect measured in the experiments on a single bremsstrahlung at Novosibirsk{close_quote}s VEPP-4 and DESY HERA. {copyright} {ital 1996 The American Physical Society.}

  14. Size Matters: Are Physically Large People More Likely to be Violent?

    Science.gov (United States)

    Salas-Wright, Christopher P; Vaughn, Michael G

    2016-04-01

    A number of studies suggest that physical size is associated with violent behavior. However, few, if any, studies have examined this relationship using population-based samples. Moreover, limited evidence exists on the relationship between physical size and violence with respect to gender, race/ethnicity, and exposure to childhood maltreatment. The present study, using data from Waves I and II (N = 34,653) of the National Epidemiologic Survey of Alcohol and Related Conditions (NESARC), aims to address these gaps by comparing the prevalence of violent behavior among individuals in the top quintiles in height and weight with that of the general population. Significant associations were identified for both males and females between physical size and bullying/intimidation, intentional injury of other persons, and hitting someone so hard that they required medical attention. Stratified analyses revealed that the magnitude of the relationship between physical size and violence is greater among Hispanics than among non-Hispanic Whites and African Americans. Childhood abuse and neglect significantly moderated the relationship between physical size and violent behavior. While an important degree of variability can be observed with respect to gender, race/ethnicity, and exposure to child maltreatment, results indicate that, in general, physically larger individuals are more likely than their relatively smaller counterparts to be violent. PMID:25535251

  15. Pre-service physics teachers' ideas on size, visibility and structure of the atom

    International Nuclear Information System (INIS)

    Understanding the atom gives the opportunity to both understand and conceptually unify the various domains of science, such as physics, chemistry, biology, astronomy and geology. Among these disciplines, physics teachers are expected to be particularly well educated in this topic. It is important that pre-service physics teachers know what sort of theories regarding the atom they will bring into their own classrooms. Six tasks were developed, comprising size, visibility and structure of the atom. These tasks carried out by pre-service physics teachers were examined by content analysis and six categories were determined. These are size, visibility, subatomic particles, atom models, electron orbit and electron features. Pre-service physics teachers' ideas about the atom were clarified under these categories.

  16. Physical mechanism of the linear beam-size effect at colliders

    CERN Document Server

    Melnikov, K; Serbo, V G

    1996-01-01

    We present qualitative but precise description of the linear beam-size effect predicted for the processes in which unstable but long--living particles collide with each other. We derive physically pronounced equation for the events rate which proves that the linear beam-size effect corresponds to the scattering of one beam of particles on the decay products of the other. We compare this linear beam-size effect with the known logarithmic beam-size effect measured in the experiments on a single bremsstrahlung at VEPP-4 and HERA.

  17. Size-controlled bismuth nanoparticles physically grown by the support of cobalt atomic flux

    Science.gov (United States)

    Lee, Ho Seok; Noh, Jin-Seo

    2016-04-01

    Bi nanoparticle arrays with the almost monodispersity were synthesized using a magnetically assisted physical method. The average size and the overall morphology of Bi nanoparticles could be controlled by the adjustment of several parameters such as relative powers applied to Bi and Co targets, substrate temperature, and growth time. It was disclosed that Bi nanoparticles grow larger at a higher relative power to Bi, higher substrate temperature, and longer growth time, accompanying the deterioration of well-developed faceted structures. This physical method may provide a facile and fast route to achieving quality Bi nanoparticle arrays with a certain extent of size and morphology controllability.

  18. Sizing up the Threat: The Envisioned Physical Formidability of Terrorists Tracks Their Leaders' Failures and Successes

    Science.gov (United States)

    Holbrook, Colin; Fessler, Daniel M. T.

    2013-01-01

    Victory in modern intergroup conflict derives from complex factors, including weaponry, economic resources, tactical outcomes, and leadership. We hypothesize that the mind summarizes such factors into simple metaphorical representations of physical size and strength, concrete dimensions that have determined the outcome of combat throughout both…

  19. Effects of particle size distribution on some physical, chemical and functional properties of unripe banana flour.

    Science.gov (United States)

    Savlak, Nazlı; Türker, Burcu; Yeşilkanat, Nazlıcan

    2016-12-15

    The objective of this study was to examine the effect of particle size distribution on physical, chemical and functional properties of unripe banana flour for the first time. A pure triploid (AAA group) of Musa acuminata subgroup Cavendish (°Brix;0.2, pH;4.73, titratable acidity; 0.56g/100g malic acid, total solids; 27.42%) which was supplied from Gazipaşa, Antalya, Turkey from October 2014 to October 2015 was used. Size fractions of physical, functional and antioxidant properties. Particle size significantly effected color, water absorbtion index and wettability. L(∗) value decreased, a(∗) and b(∗) values decreased by increasing particle size (r(2)=-0.94, r(2)=0.72, r(2)=0.73 respectively). Particles under 212μm had the lowest rate of wettability (83.40s). A negative correlation between particle size and wettability (r(2)=-0.75) and positive correlation between particle size and water absorption index (r(2)=0.94) was observed.

  20. Effects of particle size distribution on some physical, chemical and functional properties of unripe banana flour.

    Science.gov (United States)

    Savlak, Nazlı; Türker, Burcu; Yeşilkanat, Nazlıcan

    2016-12-15

    The objective of this study was to examine the effect of particle size distribution on physical, chemical and functional properties of unripe banana flour for the first time. A pure triploid (AAA group) of Musa acuminata subgroup Cavendish (°Brix;0.2, pH;4.73, titratable acidity; 0.56g/100g malic acid, total solids; 27.42%) which was supplied from Gazipaşa, Antalya, Turkey from October 2014 to October 2015 was used. Size fractions of <212, 212-315, 316-500 and 501-700μm were characterized for their physical, functional and antioxidant properties. Particle size significantly effected color, water absorbtion index and wettability. L(∗) value decreased, a(∗) and b(∗) values decreased by increasing particle size (r(2)=-0.94, r(2)=0.72, r(2)=0.73 respectively). Particles under 212μm had the lowest rate of wettability (83.40s). A negative correlation between particle size and wettability (r(2)=-0.75) and positive correlation between particle size and water absorption index (r(2)=0.94) was observed. PMID:27451170

  1. Objectively measured daily physical activity related to cardiac size in young children

    DEFF Research Database (Denmark)

    Dencker, M; Thorsson, O; Karlsson, M K;

    2009-01-01

    ), aged 8-11 years, from a population-based cohort. Left ventricular end-diastolic diameter (LVDD) and left atrial end-systolic diameter (LA) were measured with echocardiography and indexed for body surface area (BSA). Physical activity was assessed by accelerometry, and the duration of vigorous physical...... activity per day (VPA) was calculated. Acceptable accelerometer and echocardiography measurements were obtained in 228 children (boys=127, girls=101). Univariate correlations between VPA and LVDD were indexed for BSA in boys (r=0.27, P... that independent factors for LVDD, indexed for BSA for boys, were age and VPA. LA indexed for BSA was not related to physical activity variables in either gender. No clear relationship exists between cardiac size and daily physical activity in children aged 8-11 years. This suggests that significant cardiac...

  2. Influence of particle size and preparation methods on the physical and chemical stability of amorphous simvastatin

    DEFF Research Database (Denmark)

    Zhang, Fang; Aaltonen, Jaakko; Tian, Fang;

    2009-01-01

    This study investigated the factors influencing the stability of amorphous simvastatin. Quench-cooled amorphous simvastatin in two particle size ranges, 150-180 microm (QC-big) and ... stability were investigated. Physical stability (crystallization) of amorphous simvastatin stored at two conditions was monitored by X-ray powder diffractometry (XRPD) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Assessment of enthalpy relaxation of amorphous forms was conducted...... using DSC in order to link the physical and chemical stability with molecular mobility. Chemical stability was studied with high-performance liquid chromatography (HPLC). Results obtained from the current study revealed that the solubility of amorphous forms prepared by both methods was enhanced...

  3. Beam Size Estimation from Luminosity Scans at the LHC During 2015 Proton Physics Operation

    CERN Document Server

    Hostettler, Michael

    2016-01-01

    As a complementary method for measuring the beam size for high-intensity beams at 6.5 TeV flat-top energy, beam separation scans were done regularly at the CERN Large Hadron Collider (LHC) during 2015 proton physics operation. The luminosities measured by the CMS experiment during the scans were used to derive the convoluted beam size and orbit offset bunch-by-bunch. This contribution will elaborate on the method used to derive plane-by-plane, bunch-by-bunch emittances from the scan data, including uncertainties and corrections. The measurements are then compared to beam size estimations from absolute luminosity, synchrotron light telescopes, and wire scanners. In particular, the evolution of the emittance over the course of several hours in collisions is studied and bunch-by-bunch differences are highlighted.

  4. Built Environment Influences of Children's Physical Activity: Examining Differences by Neighbourhood Size and Sex.

    Science.gov (United States)

    Mitchell, Christine A; Clark, Andrew F; Gilliland, Jason A

    2016-01-01

    Neighbourhoods can facilitate or constrain moderate-to-vigorous physical activity (MVPA) among children by providing or restricting opportunities for MVPA. However, there is no consensus on how to define a child's neighbourhood. This study examines the influence of the neighbourhood built environment on objectively measured MVPA among 435 children (aged 9-14 years) in London (ON, Canada). As there is no consensus on how to delineate a child's neighbourhood, a geographic information system was used to generate measures of the neighbourhood built environment at two buffer sizes (500 m and 800 m) around each child's home. Linear regression models with robust standard errors (cluster) were used to analyze the relationship between built environment characteristics and average daily MVPA during non-school hours on weekdays. Sex-stratified models assessed sex-specific relationships. When accounting for individual and neighbourhood socio-demographic variables, park space and multi-use path space were found to influence children's MVPA. Sex-stratified models found significant associations between MVPA and park space, with the 800 m buffer best explaining boys' MVPA and the 500 m buffer best explaining girls' MVPA. Findings emphasize that, when designing built environments, programs, and policies to facilitate physical activity, it is important to consider that the size of the neighbourhood influencing a child's physical activity may differ according to sex. PMID:26784212

  5. Minor effect of physical size sorting on iron solubility of transported mineral dust

    Directory of Open Access Journals (Sweden)

    Z. B. Shi

    2011-08-01

    Full Text Available Observations show that the fractional solubility of Fe (FS-Fe, percentage of dissolved to total Fe in dust aerosol increases considerably from 0.1 % in regions of high dust mass concentration to 80 % in remote regions where concentrations are low. Here, we combined laboratory geochemical measurements with global aerosol model simulations to test the hypothesis that the increase in FS-Fe is due to physical size sorting during transport. We determined the FS-Fe and fractional solubility of Al (FS-Al in size-fractionated dust generated from two representative soil samples collected from known Saharan dust source regions using a customized dust re-suspension and collection system. The results show that the FS-Fe is size-dependent and ranges from 0.1–0.3 % in the coarse size fractions (>1 μm to ~0.2–0.8 % in the fine size fractions (<1 μm. The FS-Al shows a similar size distribution to that of the FS-Fe. The size-resolved FS-Fe data were then combined with simulated dust mass concentration and size distribution data from a global aerosol model, GLOMAP, to calculate the FS-Fe of dust aerosol over the tropical and subtropical North Atlantic Ocean. We find that the calculated FS-Fe in the dust aerosol increases systematically from ~0.1 % at high dust mass concentrations (e.g., >100 μg m−3 to ~0.2 % at low concentrations (<100 μg m–3 due to physical size sorting (i.e., particle gravitational settling. These values are one to two orders of magnitude smaller than those observed on cruises across the tropical and sub-tropical North Atlantic Ocean under an important pathway of Saharan dust plumes for similar dust mass concentrations. Even when the FS-Fe of sub-micrometer size fractions (0.18–0.32 μm, 0.32–0.56 μm, and 0.56–1.0 μm in the model is increased by a factor of 10 over the measured values, the calculated FS-Fe of the dust is still more than an order of magnitude lower than that measured in the field

  6. Minor effect of physical size sorting on iron solubility of transported mineral dust

    Directory of Open Access Journals (Sweden)

    Z. B. Shi

    2011-05-01

    Full Text Available Observations show that the fractional solubility of Fe (FS-Fe, ratio of dissolved to total Fe in dust aerosol increases dramatically from ~0.1% in regions of high dust mass concentration to 80% in remote regions where concentrations are low. Here, we combined laboratory geochemical measurements with global aerosol model simulations to test the hypothesis that the increase in FS-Fe is due to physical size sorting during transport. We determined the FS-Fe and fractional solubility of Al (FS-Al in size-fractionated dust generated from two representative soil samples collected from known Saharan dust source regions using a customized dust re-suspension and collection system. The results show that the FS-Fe is size-dependent and ranges from 0.1–0.3 % in the coarse size fractions (>1 μm to ~0.2–0.8 % in the fine size fractions (<1 μm. The FS-Al shows a similar size distribution to that of FS-Fe. The size-resolved FS-Fe data were then combined with simulated dust mass concentration and size distribution data from a global aerosol model, GLOMAP, to calculate the FS-Fe of dust aerosol over the tropical and subtropical North Atlantic Ocean. We find that the calculated FS-Fe in the dust aerosol increases systematically from ~0.1 % at high dust mass concentrations (e.g., >100 μg m−3 to ~0.2 % at low concentrations (<100 μg m−3 due to physical size sorting (i.e., particle gravitational settling. These values are one to two orders of magnitude smaller than those observed on cruises across the tropical and sub-tropical North Atlantic Ocean under an important pathway of Saharan dust plumes for similar dust mass concentrations. Even when the FS-Fe of sub-micrometer size fractions (0.18–0.32 μm, 0.32–0.56 μm, and 0.56–1.0 μm in the model is increased by a factor of 10 over the measured values, the calculated FS-Fe of the dust is still more than an order of magnitude lower than that measured in the field. Therefore, the

  7. Physics-Based Reactive Burn Model: Grain size effects and binder effects

    Science.gov (United States)

    Lu, Xia; Hamate, Yuichio; Horie, Yasuyuki

    2007-06-01

    We have been developing a physics-based reactive burn (PBRB) model aiming at expanding predictive capability. The PBRB model was formulated based on the concept of a statistical hot spot cell. In the model, thermomechanics and physiochemical features are explicitly modeled. In this paper, we have extended the statistical hot spot model to explicitly describe the ignition and growth of hot spots. In particular, grain size effects are explicitly delineated through introduction of a size-dependent thickness of the hot-region thickness, a size-dependent energy deposition criterion, and a specific surface area. Besides the linear relationships between the run distance to detonation and critical diameter with the reciprocal specific surface area of HE, as discussed in a parallel paper in this meeting, parametric studies have also shown that the PBRB can predict a non-monotonous variation of shock sensitivity with grain size, as observed by Moulard et al. The purpose of this work is to extend the model to include the effects of explosive binders explicitly. As a first step we investigate the thermomechanical effects of a binder by using direct mesoscale simulations. The results will be used in the extending the PBRB model to include binder thermomechanics explicitly.

  8. Computing physical properties with quantum Monte Carlo methods with statistical fluctuations independent of system size.

    Science.gov (United States)

    Assaraf, Roland

    2014-12-01

    We show that the recently proposed correlated sampling without reweighting procedure extends the locality (asymptotic independence of the system size) of a physical property to the statistical fluctuations of its estimator. This makes the approach potentially vastly more efficient for computing space-localized properties in large systems compared with standard correlated methods. A proof is given for a large collection of noninteracting fragments. Calculations on hydrogen chains suggest that this behavior holds not only for systems displaying short-range correlations, but also for systems with long-range correlations.

  9. The statistical and practical significance and "effect size" coefficients for the evaluation of physical activity

    Directory of Open Access Journals (Sweden)

    Dagmar Sigmundová

    2012-01-01

    Full Text Available BACKGROUND: An adequate statistical analysis of obtained data is a necessary condition for the right interpretation of results followed by correct formulation of conclusions. The use of appropriate statistical procedures is repeatedly a subject of justified criticism and recommendations in our and other international publications. For example, during the interpretation of results we often "blindly" rely on the statistical significance, and the practical significance of the research is ignored. OBJECTIVE: The main aim of this study is to highlight the formulation of the practical significance of the results and its correct interpretation. We used an analysis of the international studies and own findings from physical activity monitoring. Another aim is to introduce an applicable effect size coefficient as a guide for assessing the practical significance. METHODS: Materials for formulating rules to assess the practical significance and introduction of effect size coefficients was comprised of the 29 international and Czech studies about the level of week and short time (PE lesson, training, exercise lesson physical activity of Czech children and adolescents (1,129 girls and 938 boys, and adults (5,727 females and 5,426 males with use of accelerometers, pedometers and IPAQ questionnaires during 2000-2010. RESULTS: Rules for assessing the practical significance consider measurement error, data variability and the size of position from the beginning on the measurement scale. The formulation of the practical significance should include - a a determination of the minimal values of certain measurement unit that will be limiting for assessing the significancy of the difference; b the determination of a minimal size of mutual relationship between the expected results and findings. The presentation of the "effect size" coefficients (d, r, r2, K2, ω2 comprises of their definition, the conditions for use as well as the calculation and interpretation of

  10. Physical conditions in three high-z H2-bearing DLAs: implications for grain size

    Science.gov (United States)

    Shaw, Gargi; Rawlins, Katherine; Srianand, Raghunathan

    2016-07-01

    We present results of our numerical simulation of three H2-bearing damped Lyman α absorbers (DLAs) in the redshift interval ˜ 2-3. The systems we have modelled are the DLAs at zabs = 2.3377 towards the quasar LBQS 1232 + 0815, at zabs = 2.418 37 towards SDSS J143912.04 + 111740.5 and at zabs = 2.6265 towards FBQS J081240.6 + 320808. We have used the spectral synthesis code CLOUDY to simulate the physical environment of these DLAs, and constrain the density, radiation field, geometry and dust-grain properties of the DLAs self-consistently based on the observed column densities of various atomic and molecular species such as H I, fine structure lines of C I and the rotational level population of H2. In our models, we explore the effect of grain size distribution on the predicted column densities of different species. Within the allowed uncertainties in the inferred dust-to-gas ratio, both models with standard interstellar medium grains and smaller sized grains reproduce the observations equally well. Improved constraints on dust-to-gas ratio and line-of-sight extinction are important for probing the grain size distribution in high-z DLAs. We find the H2-bearing clouds to have line-of-sight thickness in the range 1-6 pc, consistent with what has been found using partial coverage or 21-cm observations in some high-z DLAs.

  11. Structures and Properties of Nanometer Size Materials Ⅲ. Structures and Physical Properties of Iron Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    李小华; 马美华

    2005-01-01

    Molecular dynamics computer simulation has been carded out to study the structure and physical properties of iron nanoparticles with 331 to 2133 Fe atoms or with diameter from 2.3 to 4.3 nm. The core of liquid nanodroplets has the similar structure of the bulk molten iron liquid that has an average coordination number around 10.5 and the packing density around 0.45, although the closest Fe-Fe distance is slightly longer in the bulk liquid. Most of the iron nanoparticles formed from the cooling of molten nanodroplets have the same body center cubic crystal structure as it was observed in the bulk under the normal temperature and pressure. Lattice contraction was observed for iron nanoparticles. An amorphous solid and an HCP like solid were obtained accidentally during the quenching runs on Fe331 nanoparticles. The physical properties of iron nanoparticles such as molar volume, density, thermal expansion coefficient, melting point, heat of fusion, heat capacity and diffusion coefficient were estimated based on the results obtained from this simulation. The dependence of physical properties on the nanoparticle sizes was addressed.

  12. The effect of shredding and particle size in physical and chemical processing of printed circuit boards waste

    OpenAIRE

    Oliveira, Paula C.; Taborda, F. Charters; Nogueira, C. A.; Margarido, F.

    2011-01-01

    Circuit boards present in most electric and electronic devices are very important components, which should be removed during sorting and dismantling operations in order to allow further adequate treatment for recovering valuable metals such as copper, nickel, zinc, lead, tin and rare elements. This recovery can be made by physical and chemical processes being size reduction by shredding the first step. In this paper, the effect of particle size in physical and chemical processing of printed c...

  13. Simulation of the main physical processes in remote laser penetration with large laser spot size

    Directory of Open Access Journals (Sweden)

    S. A. Khairallah

    2015-04-01

    Full Text Available A 3D model is developed to simulate remote laser penetration of a 1mm Aluminum metal sheet with large laser spot size (∼ 3x3cm2, using the ALE3D multi-physics code. The model deals with the laser-induced melting of the plate and the mechanical interaction between the solid and the melted part through plate elastic-plastic response. The effect of plate oscillations and other forces on plate rupture, the droplet formation mechanism and the influence of gravity and high laser power in further breaking the single melt droplet into many more fragments are analyzed. In the limit of low laser power, the numerical results match the available experiments. The numerical approach couples mechanical and thermal diffusion to hydrodynamics melt flow and accounts for temperature dependent material properties, surface tension, gravity and vapor recoil pressure.

  14. Bimodal distribution of the magnetic dipole moment in nanoparticles with a monomodal distribution of the physical size

    NARCIS (Netherlands)

    van Rijssel, Jozef; Kuipers, Bonny W M; Erne, Ben

    2015-01-01

    High-frequency applications of magnetic nanoparticles, such as therapeutic hyperthermia and magnetic particle imaging, are sensitive to nanoparticle size and dipole moment. Usually, it is assumed that magnetic nanoparticles with a log-normal distribution of the physical size also have a log-normal d

  15. 78 FR 74154 - Draft Guidance for Industry on Size, Shape, and Other Physical Attributes of Generic Tablets and...

    Science.gov (United States)

    2013-12-10

    ... Physical Attributes of Generic Tablets and Capsules; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug Administration (FDA) is announcing the availability of a draft guidance for industry entitled ``Size, Shape, and Other Physical Attributes of Generic Tablets and...

  16. MANIPULATION OF PHYSICAL FUNCTIONALITY OF BULK DRUG POWDER: AGGLOMERATE SIZE APPROACH

    Directory of Open Access Journals (Sweden)

    Kale Vinita

    2011-06-01

    Full Text Available Agglomeration is a size enlargement process in which primary particles stick together to form agglomerates. In past, various techniques have been developed to form agglomerates. One of the aims of this study was to form agglomerates using solvent treated method and traditional wet granulation method of a bulk drug and to study the effect of agglomeration on physical functionality of agglomerated and original bulk powders. Another objective of the study was to prepare compact of the agglomerated powders and bulk powder and to study their compactibility properties. The solvent treated agglomeration process was performed using 5% aqueous ammonia solution at different stirring speed and time. Powder flow and compactibility were considered as functionality parameters. Powder flowability was expressed in terms of – size and shape of particles, static angle of repose, Hausner ratio, Carrs index, porosity and packability. The compacts of agglomerated powders and bulk powder were prepared and tested for compressibility properties. All the powder functional properties of the solvent treated agglomerates were dramatically improved. Compacts by direct compression method could be formed successfully of solvent treated agglomerate powder that was comparable with the wet granules. The original powder of bulk drug failed to be compressed by direct compression method. Thus solvent treated agglomerates provided the requirements needed to convert wet granulated formulations to direct compression formulations, thus avoiding labor and energy intensive of wet granulation processes and is an alternative to develop cost effective formulations.

  17. Physical conditions in three high-z H2-bearing DLAs: implications for grain size

    CERN Document Server

    Rawlins, Katherine; Srianand, Raghunathan

    2016-01-01

    We present results of our numerical simulation of three H2-bearing damped Lyman alpha absorbers (DLAs) in the redshift interval ~ 2-3. The systems we have modelled are the DLAs at zabs = 2.3377 towards the quasar LBQS 1232+0815, at zabs = 2.41837 towards SDSS J143912.04+111740.5 and at zabs = 2.6265 towards FBQS J081240.6+320808. We have used the spectral synthesis code CLOUDY to simulate the physical environment of these DLAs, and constrain the density, radiation field, geometry and dust-grain properties of the DLAs self-consistently based on the observed column densities of various atomic and molecular species such as H I, fine structure lines of C I and the rotational level population of H2. In our models, we explore the effect of grain size distribution on the predicted column densities of different species. Within the allowed uncertainties in the inferred dust-to-gas ratio, both models with standard ISM grains and smaller-sized grains reproduce the observations equally well. Improved constraints on dust-...

  18. Statistical physics studies of multilayer adsorption isotherm in food materials and pore size distribution

    Science.gov (United States)

    Aouaini, F.; Knani, S.; Ben Yahia, M.; Ben Lamine, A.

    2015-08-01

    Water sorption isotherms of foodstuffs are very important in different areas of food science engineering such as for design, modeling and optimization of many processes. The equilibrium moisture content is an important parameter in models used to predict changes in the moisture content of a product during storage. A formulation of multilayer model with two energy levels was based on statistical physics and theoretical considerations. Thanks to the grand canonical ensemble in statistical physics. Some physicochemical parameters related to the adsorption process were introduced in the analytical model expression. The data tabulated in literature of water adsorption at different temperatures on: chickpea seeds, lentil seeds, potato and on green peppers were described applying the most popular models applied in food science. We also extend the study to the newest proposed model. It is concluded that among studied models the proposed model seems to be the best for description of data in the whole range of relative humidity. By using our model, we were able to determine the thermodynamic functions. The measurement of desorption isotherms, in particular a gas over a solid porous, allows access to the distribution of pore size PSD.

  19. Statistical and Physical Descriptions of Raindrop Size Distributions in Equatorial Malaysia from Disdrometer Observations

    Directory of Open Access Journals (Sweden)

    Hong Yin Lam

    2015-01-01

    Full Text Available This work investigates the physical characteristics of raindrop size distribution (DSD in an equatorial heavy rain region based on three years of disdrometer observations carried out at Universiti Teknologi Malaysia’s (UTM’s campus in Kuala Lumpur, Malaysia. The natural characteristics of DSD are deduced, and the statistical results are found to be in accordance with the findings obtained from others disdrometer measurements. Moreover, the parameters of the Gamma distribution and the normalized Gamma model are also derived by means of method of moment (MoM and maximum likelihood estimation (MLE. Their performances are subsequently validated using the rain rate estimation accuracy: the normalized Gamma model with the MLE-generated shape parameter µ was found to provide better accuracy in terms of long-term rainfall rate statistics, which reflects the peculiarities of the local climatology in this heavy rain region. These results not only offer a better understanding of the microphysical nature of precipitation in this heavy rain region but also provide essential information that may be useful for the scientific community regarding remote sensing and radio propagation.

  20. Chondrule size and related physical properties: a compilation and evaluation of current data across all meteorite groups

    CERN Document Server

    Friedrich, Jon M; Ebel, Denton S; Biltz, Alison E; Corbett, Bernadette M; Iotzov, Ivan V; Khan, Wajiha S; Wolman, Matthew D

    2014-01-01

    The examination of the physical properties of chondrules has generally received less emphasis than other properties of meteorites such as their mineralogy, petrology, and chemical and isotopic compositions. Among the various physical properties of chondrules, chondrule size is especially important for the classification of chondrites into chemical groups, since each chemical group possesses a distinct size-frequency distribution of chondrules. Knowledge of the physical properties of chondrules is also vital for the development of astrophysical models for chondrule formation, and for understanding how to utilize asteroidal resources in space exploration. To examine our current knowledge of chondrule sizes, we have compiled and provide commentary on available chondrule dimension literature data. We include all chondrite chemical groups as well as the acapulcoite primitive achondrites, some of which contain relict chondrules. We also compile and review current literature data for other astrophysically-relevant p...

  1. Pre-Service Physics Teachers' Ideas on Size, Visibility and Structure of the Atom

    Science.gov (United States)

    Unlu, Pervin

    2010-01-01

    Understanding the atom gives the opportunity to both understand and conceptually unify the various domains of science, such as physics, chemistry, biology, astronomy and geology. Among these disciplines, physics teachers are expected to be particularly well educated in this topic. It is important that pre-service physics teachers know what sort of…

  2. Domain size engineering of CVD graphene and its influence on physical properties

    Science.gov (United States)

    Annisanti Mas’ud, Felisita; Cho, Hyunjin; Lee, Taegeon; Rho, Heesuk; Seo, Tae Hoon; Jong Kim, Myung

    2016-05-01

    An electrochemical polishing pre-treatment and atmospheric pressure annealing were performed on copper foils in order to obtain large graphene domain sizes by the chemical vapor deposition method. The sizes were confirmed through scanning electron microscopy, optical microscopy and Raman spectroscopy, among other additional characterizations. The larger domain size was expected to improve the quality of the graphene but, on the contrary, the sheet resistance of the samples was found to increase for the larger domain size. We conclude that although the domain size is larger, the sheet resistance of graphene is more affected by the quality of the graphene interdomain itself.

  3. "Every Child (of Every Size) Matters" in Physical Education! Physical Education's Role in Childhood Obesity

    Science.gov (United States)

    Cale, Lorraine; Harris, Jo

    2013-01-01

    The role of schools and physical education in promoting health, producing a "healthy nation" and in tackling obesity has been increasingly recognised in recent years. In England this is evidenced by various policies, strategies and responses from government that have highlighted schools to be instrumental in addressing health broadly and…

  4. Body size, physical activity and risk of colorectal cancer with or without the CpG island methylator phenotype (CIMP)

    NARCIS (Netherlands)

    Hughes, L.A.E.; Simons, C.C.J.M.; Brandt, P.A. van den; Goldbohm, R.A.; Goeij, A.F. de; Bruïne, A.P. de; Engeland, M. van; Weijenberg, M.P.

    2011-01-01

    Background: We investigated how body size and physical activity influence the risk of the CpG island methylator phenotype (CIMP) in colorectal cancer (CRC). Methods: In the Netherlands Cohort Study (n = 120,852), risk factors were self-reported at baseline in 1986. After 7.3 years of follow-up, 603

  5. Size and Fraction of Active Surface Area of Some Jupiter Family Comets: Implications with Respect to their Physical Evolution

    Directory of Open Access Journals (Sweden)

    Julio A. Fernández

    2001-01-01

    Full Text Available We analyze the sample of measured nuclear magnitudes of the observed Jupiter Family comets (taken as those with orbital periods P 2 to derive sizes of comet nuclei, fraction of active surface areas, as well as to try to gain insight about their physical lifetimes and end states.

  6. Physics with small and large size facilities at IFIN-HH Bucharest-Magurele

    International Nuclear Information System (INIS)

    The 'Horia Hulubei' National Institute for Physics and Nuclear Engineering (IFIN-HH) in Bucharest-Magurele is the prime research institute in Romania. With 12 departments, it combines the entire range of duties of a nuclear physics national laboratory with fundamental research in nuclear and particle physics and with applications based on atomic and nuclear techniques. After a brief presentation of the whole institute, past, present and future, I will concentrate on physics we do with small accelerators and other facilities, with emphasis on areas of environment and cultural heritage study and preservation. (author)

  7. Pore Size Distribution as a Soil Physical Quality Index for Agricultural and Pasture Soils in Northeastern Iran

    Institute of Scientific and Technical Information of China (English)

    H.SHAHAB, H.EMAMI; G.H.HAGHNIA; A.KARIMI

    2013-01-01

    Assessment of soil quality is important for optimum production and natural resources conservation.Agricultural and pasture soil qualities of Deh-Sorkh region located at south of Mashhad,northeastern Iran were assessed using the integrated quality index (IQI) and Nemero quality index (NQI) models in combination with two datasets,i.e.,total data set (TDS) and minimum data set (MDS).In this study 6 soil properties considered as MDS were selected out of 18 properties as TDS using principle component analysis.Soil samples were divided into 3 groups based on optimum ranges of 8 soil physical quality indicators.Soil samples with the most indicators at optimum range were selected as group 1 and the samples having fewer indicators at optimum range were located in groups 2 and 3.Optimum ranges of soil pore size distribution functions were also determined as soil physical quality indices based on 8 soil physical quality indicators.Pore size distribution curves of group 1 were considered as the optimum pore size functions.The results showed that relatively high organic carbon contents could improve pore size distribution.Mean comparisons of soil physical quality indicators demonstrated that mean weight diameter of wet aggregates,structural stability index,the slope of moisture retention curve at inflection point,and plant available water content in agricultural land use decreased significantly in relation to pasture land use.In addition,the results demonstrated that the studied MDS could be a suitable representative of TDS.78% of pasture soils had the optimum pore size distribution functions,while this parameter for agricultural soils was only 13%.In general,the soils of the studied region showed high limitations for plant growth according to the studied indicators.

  8. Bimodal distribution of the magnetic dipole moment in nanoparticles with a monomodal distribution of the physical size

    Energy Technology Data Exchange (ETDEWEB)

    Rijssel, Jos van; Kuipers, Bonny W.M.; Erné, Ben H., E-mail: B.H.Erne@uu.nl

    2015-04-15

    High-frequency applications of magnetic nanoparticles, such as therapeutic hyperthermia and magnetic particle imaging, are sensitive to nanoparticle size and dipole moment. Usually, it is assumed that magnetic nanoparticles with a log-normal distribution of the physical size also have a log-normal distribution of the magnetic dipole moment. Here, we test this assumption for different types of superparamagnetic iron oxide nanoparticles in the 5–20 nm range, by multimodal fitting of magnetization curves using the MINORIM inversion method. The particles are studied while in dilute colloidal dispersion in a liquid, thereby preventing hysteresis and diminishing the effects of magnetic anisotropy on the interpretation of the magnetization curves. For two different types of well crystallized particles, the magnetic distribution is indeed log-normal, as expected from the physical size distribution. However, two other types of particles, with twinning defects or inhomogeneous oxide phases, are found to have a bimodal magnetic distribution. Our qualitative explanation is that relatively low fields are sufficient to begin aligning the particles in the liquid on the basis of their net dipole moment, whereas higher fields are required to align the smaller domains or less magnetic phases inside the particles. - Highlights: • Multimodal fits of dilute ferrofluids reveal when the particles are multidomain. • No a priori shape of the distribution is assumed by the MINORIM inversion method. • Well crystallized particles have log-normal TEM and magnetic size distributions. • Defective particles can combine a monomodal size and a bimodal dipole moment.

  9. Estimation of Pore Size Distribution by CO2 Adsorptionand Its Application in Physical Activation of Precursors

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The CO2 adsorption data may show more than one section in theDubinin-Radushkevich-Kaganer(DRK) plot ifsamples had been over-activated. Each section in the plot represents arange of pore size.The whole DRK plot provided information on the pore size distribution(PSD)of a sample, which may be used to monitor the effect of activationconditions in activation processes.

  10. Mechanisms of temperature-dependent swimming: the importance of physics, physiology and body size in determining protist swimming speed.

    Science.gov (United States)

    Beveridge, Oliver S; Petchey, Owen L; Humphries, Stuart

    2010-12-15

    Body temperatures and thus physiological rates of poikilothermic organisms are determined by environmental temperature. The power an organism has available for swimming is largely dependent on physiological rates and thus body temperature. However, retarding forces such as drag are contingent on the temperature-dependent physical properties of water and on an organism's size. Consequently, the swimming ability of poikilotherms is highly temperature dependent. The importance of the temperature-dependent physical properties of water (e.g. viscosity) in determining swimming speed is poorly understood. Here we propose a semi-mechanistic model to describe how biological rates, size and the physics of the environment contribute to the temperature dependency of microbial swimming speed. Data on the swimming speed and size of a predatory protist and its protist prey were collected and used to test our model. Data were collected by manipulating both the temperature and the viscosity (independently of temperature) of the organism's environment. Protists were either cultured in their test environment (for several generations) or rapidly exposed to their test environment to assess their ability to adapt or acclimate to treatments. Both biological rates and the physics of the environment were predicted to and observed to contribute to the swimming speed of protists. Body size was not temperature dependent, and protists expressed some ability to acclimate to changes in either temperature or viscosity. Overall, using our parameter estimates and novel model, we are able to suggest that 30 to 40% (depending on species) of the response in swimming speed associated with a reduction in temperature from 20 to 5°C is due to viscosity. Because encounter rates between protist predators and their prey are determined by swimming speed, temperature- and viscosity-dependent swimming speeds are likely to result in temperature- and viscosity-dependent trophic interactions. PMID:21113003

  11. Mechanisms of temperature-dependent swimming: the importance of physics, physiology and body size in determining protist swimming speed

    OpenAIRE

    Beveridge, Oliver S; Petchey, Owen L; Humphries, Stuart

    2010-01-01

    Body temperatures and thus physiological rates of poikilothermic organisms are determined by environmental temperature. The power an organism has available for swimming is largely dependent on physiological rates and thus body temperature. However, retarding forces such as drag are contingent on the temperature-dependent physical properties of water and on an organism’s size. Consequently, the swimming ability of poikilotherms is highly temperature dependent. The importance of the te...

  12. Does activity space size influence physical activity levels of adolescents?—A GPS study of an urban environment

    OpenAIRE

    Lee, Nolan C.; Voss, Christine; Frazer, Amanda D.; Hirsch, Jana A.; McKay, Heather A; Winters, Meghan

    2015-01-01

    Background Physical activity (PA) is closely linked with child and youth health, and active travel may be a solution to enhancing PA levels. Activity spaces depict the geographic coverage of one's travel. Little is known about activity spaces and PA in adolescents. Objective To explore the relation between adolescent travel (using a spatial measure of activity space size) and daily moderate-to-vigorous PA (MVPA), with a focus on school days. Methods We used Global Positioning Systems to manua...

  13. Mineralogical, optical, geochemical, and particle size properties of four sediment samples for optical physics research

    Science.gov (United States)

    Bice, K.; Clement, S. C.

    1981-01-01

    X-ray diffraction and spectroscopy were used to investigate the mineralogical and chemical properties of the Calvert, Ball Old Mine, Ball Martin, and Jordan Sediments. The particle size distribution and index of refraction of each sample were determined. The samples are composed primarily of quartz, kaolinite, and illite. The clay minerals are most abundant in the finer particle size fractions. The chemical properties of the four samples are similar. The Calvert sample is most notably different in that it contains a relatively high amount of iron. The dominant particle size fraction in each sample is silt, with lesser amounts of clay and sand. The indices of refraction of the sediments are the same with the exception of the Calvert sample which has a slightly higher value.

  14. In situ exhaust cloud measurements. [particle size distribution and cloud physics of rocket exhaust clouds

    Science.gov (United States)

    Wornom, D.

    1980-01-01

    Airborne in situ exhaust cloud measurements were conducted to obtain definitions of cloud particle size range, Cl2 content, and HCl partitioning. Particle size distribution data and Cl2 measurements were made during the May, August, and September 1977 Titan launches. The measurements of three basic effluents - HCl, NO sub X, and particles - against minutes after launch are plotted. The maximum observed HCl concentration to the maximum Cl2 concentration are compared and the ratios of the Cl2 to the HCl is calculated.

  15. Influence of the glass particle size on the foaming process and physical characteristics of foam glasses

    DEFF Research Database (Denmark)

    König, Jakob; Petersen, Rasmus Rosenlund; Yue, Yuanzheng

    2016-01-01

    We have prepared low-density foam glasses from cathode-ray-tube panel glass using carbon and MnO2 as the foaming agents. The effect of the glass particle size on the foaming process, the apparent density and the pore morphology is revealed. The results show that the foaming is mainly caused......–3 mm due to a faster coalescence process. However, by quenching the sample from the foaming to the annealing temperature the pore size is reduced by a factor of 5–10. The foams with an apparent density of

  16. Effect of particle size on thermo-physical properties of SiCp/Cu composites fabricated by squeeze casting

    Institute of Scientific and Technical Information of China (English)

    WU Gao-hui; CHEN Guo-qin; ZHU De-zhi; ZHANG Qiang; JIANG Long-tao

    2005-01-01

    For the electronic packaging applications, copper matrix composites reinforced with different sized SiC particles (10 μm, 20 μm and 63 μm) were fabricated by squeeze casting technology. And the effect of particle size on their thermo-physical properties was discussed. The composites are free of porosity and the SiC particles are distributed uniformly in the composites. It is found that the mean linear thermal expansion coefficients(20 - 100 ℃ ) of SiCp/Cu composites are in the range of (8.4 - 9.2) × 10-6/℃, and smaller expansion coefficient can be obtained for the composites with finer SiC particles because of the larger restriction in expansion through interfaces. Their thermal conductivities are reduced with the decrease of SiC sizes. This is attributed to the fact that the negative effect of interfacial thermal resistance becomes increasingly dominant as the particles becomes smaller.

  17. Wavefront-sensor-induced beam size error: physical mechanism, sensitivity-analysis and correction method

    NARCIS (Netherlands)

    Koek, W.D.; Zwet, E.J. van

    2015-01-01

    When using a commonly-used quadri-wave lateral shearing interferometer wavefront sensor (QWLSI WFS) for beam size measurements on a high power CO2 laser, artefacts have been observed in the measured irradiance distribution. The grating in the QWLSI WFS not only generates the diffracted first orders

  18. Derivation and Application of a Global Albedo yielding an Optical Brightness To Physical Size Transformation Free of Systematic Errors

    Science.gov (United States)

    Mulrooney, Dr. Mark K.; Matney, Dr. Mark J.

    2007-01-01

    Orbital object data acquired via optical telescopes can play a crucial role in accurately defining the space environment. Radar systems probe the characteristics of small debris by measuring the reflected electromagnetic energy from an object of the same order of size as the wavelength of the radiation. This signal is affected by electrical conductivity of the bulk of the debris object, as well as its shape and orientation. Optical measurements use reflected solar radiation with wavelengths much smaller than the size of the objects. Just as with radar, the shape and orientation of an object are important, but we only need to consider the surface electrical properties of the debris material (i.e., the surface albedo), not the bulk electromagnetic properties. As a result, these two methods are complementary in that they measure somewhat independent physical properties to estimate the same thing, debris size. Short arc optical observations such as are typical of NASA's Liquid Mirror Telescope (LMT) give enough information to estimate an Assumed Circular Orbit (ACO) and an associated range. This information, combined with the apparent magnitude, can be used to estimate an "absolute" brightness (scaled to a fixed range and phase angle). This absolute magnitude is what is used to estimate debris size. However, the shape and surface albedo effects make the size estimates subject to systematic and random errors, such that it is impossible to ascertain the size of an individual object with any certainty. However, as has been shown with radar debris measurements, that does not preclude the ability to estimate the size distribution of a number of objects statistically. After systematic errors have been eliminated (range errors, phase function assumptions, photometry) there remains a random geometric albedo distribution that relates object size to absolute magnitude. Measurements by the LMT of a subset of tracked debris objects with sizes estimated from their radar cross

  19. Physical properties of macromolecule-metal oxide nanoparticle complexes: Magnetophoretic mobility, sizes, and interparticle potentials

    Science.gov (United States)

    Mefford, Olin Thompson, IV

    Magnetic nanoparticles coated with polymers hold great promise as materials for applications in biotechnology. In this body of work, magnetic fluids for the treatment of retinal detachment are examined closely in three regimes; motion of ferrofluid droplets in aqueous media, size analysis of the polymer-iron oxide nanoparticles, and calculation of interparticle potentials as a means for predicting fluid stability. The macromolecular ferrofluids investigated herein are comprised of magnetite nanoparticles coated with tricarboxylate-functional polydimethylsiloxane (PDMS) oligomers. The nanoparticles were formed by reacting stoichiometric concentrations of iron chloride salts with base. After the magnetite particles were prepared, the functional PDMS oligomers were adsorbed onto the nanoparticle surfaces. The motion of ferrofluid droplets in aqueous media was studied using both theoretical modeling and experimental verification. Droplets (˜1-2 mm in diameter) of ferrofluid were moved through a viscous aqueous medium by an external magnet of measured field and field gradient. Theoretical calculations were made to approximate the forces on the droplet. Using the force calculations, the times required for the droplet to travel across particular distances were estimated. These estimated times were within close approximation of experimental values. Characterization of the sizes of the nanoparticles was particularly important, since the size of the magnetite core affects the magnetic properties of the system, as well as the long-term stability of the nanoparticles against flocculation. Transmission electron microscopy (TEM) was used to measure the sizes and size distributions of the magnetite cores. Image analyses were conducted on the TEM micrographs to measure the sizes of approximately 6000 particles per sample. Distributions of the diameters of the magnetite cores were determined from this data. A method for calculating the total particle size, including the magnetite

  20. Modification effects of physical activity and protein intake on heritability of body size and composition

    DEFF Research Database (Denmark)

    Silventoinen, Karri; Hasselbalch, Ann Louise; Lallukka, Tea;

    2009-01-01

    BACKGROUND: The development of obesity is still a poorly understood process that is dependent on both genetic and environmental factors. OBJECTIVE: The objective was to examine how physical activity and the proportion of energy as protein in the diet modify the genetic variation of body mass index...... (BMI), waist circumference, and percentage body fat. DESIGN: Twins from Denmark (756 complete pairs) and Finland (278 complete pairs) aged 18-67 and 21-24 y, respectively, participated. The proportion of energy as protein in the diet was estimated by using food-frequency questionnaires...... with the Mx statistical package (Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA). RESULTS: High physical activity was associated with lower mean values, and a high proportion of protein in the diet was associated with higher mean BMI, waist...

  1. Characterization of ambient particles size in workplace of manufacturing physical fitness equipments

    OpenAIRE

    Lin, Chih-Chung; Chen, Mei-Ru; CHANG, Sheng-Lang; LIAO, Wei-Heng; Chen, Hsiu-Ling

    2014-01-01

    The manufacturing of fitness equipment involves several processes, including the cutting and punching of iron tubes followed by welding. Welding operations produce hazardous gases and particulate matter, which can enter the alveolar, resulting in adverse health effects. This study sought to verify the particle size distribution and exposure concentrations of atmospheric air samples in various work areas of a fitness equipment manufacturing industry. Observed particle concentrations are presen...

  2. Wavefront-sensor-induced beam size error: physical mechanism, sensitivity-analysis and correction method

    OpenAIRE

    Koek, W.D.; Zwet, E.J. van

    2015-01-01

    When using a commonly-used quadri-wave lateral shearing interferometer wavefront sensor (QWLSI WFS) for beam size measurements on a high power CO2 laser, artefacts have been observed in the measured irradiance distribution. The grating in the QWLSI WFS not only generates the diffracted first orders that are required for introducing the shear, but also diffracts significantly into higher orders. Consequently, in the few millimeters of free space propagation between the QWLSI WFS grating and it...

  3. Physical Properties of Macromolecule-metal oxide nanoparticle complexes: Magnetophoretic Mobility, Size, and Interparticle Potentials

    OpenAIRE

    Mefford, Olin Thompson

    2007-01-01

    Magnetic nanoparticles coated with polymers hold great promise as materials for applications in biotechnology. In this body of work, magnetic fluids for the treatment of retinal detachment are examined closely in three regimes; motion of ferrofluid droplets in aqueous media, size analysis of the polymer-iron oxide nanoparticles, and calculation of interparticle potentials as a means for predicting fluid stability. The macromolecular ferrofluids investigated herein are comprised of magnetite...

  4. Effect of bead milling on chemical and physical characteristics of activated carbons pulverized to superfine sizes.

    Science.gov (United States)

    Partlan, Erin; Davis, Kathleen; Ren, Yiran; Apul, Onur Guven; Mefford, O Thompson; Karanfil, Tanju; Ladner, David A

    2016-02-01

    Superfine powdered activated carbon (S-PAC) is an adsorbent material with particle size between roughly 0.1-1 μm. This is about an order of magnitude smaller than conventional powdered activated carbon (PAC), typically 10-50 μm. S-PAC has been shown to outperform PAC for adsorption of various drinking water contaminants. However, variation in S-PAC production methods and limited material characterization in prior studies lead to questions of how S-PAC characteristics deviate from that of its parent PAC. In this study, a wet mill filled with 0.3-0.5 mm yttrium-stabilized zirconium oxide grinding beads was used to produce S-PAC from seven commercially available activated carbons of various source materials, including two coal types, coconut shell, and wood. Particle sizes were varied by changing the milling time, keeping mill power, batch volume, and recirculation rate constant. As expected, mean particle size decreased with longer milling. A lignite coal-based carbon had the smallest mean particle diameter at 169 nm, while the wood-based carbon had the largest at 440 nm. The wood and coconut-shell based carbons had the highest resistance to milling. Specific surface area and pore volume distributions were generally unchanged with increased milling time. Changes in the point of zero charge (pH(PZC)) and oxygen content of the milled carbons were found to correlate with an increasing specific external surface area. However, the isoelectric point (pH(IEP)), which measures only external surfaces, was unchanged with milling and also much lower in value than pH(PZC). It is likely that the outer surface is easily oxidized while internal surfaces remain largely unchanged, which results in a lower average pH as measured by pH(PZC). PMID:26657354

  5. Endurance capacity, not body size, determines physical activity levels: role of skeletal muscle PEPCK.

    Directory of Open Access Journals (Sweden)

    Colleen M Novak

    Full Text Available Some people remain lean despite pressure to gain weight. Lean people tend to have high daily activity levels, but the source of this increased activity is unknown. We found that leanness cannot be accounted for by increased weight-corrected food intake in two different types of lean rats. As previously reported in lean people, we found that lean rats had higher daily activity levels; lean rats also expended more energy. These lean rats were developed through artificial selection for high aerobic endurance capacity. To test whether our findings extended to a human population, we measured endurance capacity using a VO(2max treadmill test and daily activity in a group of non-exercising individuals. Similar to lean rats selectively bred for endurance capacity, our study revealed that people with higher VO(2max also spent more time active throughout the day. Hence, endurance capacity may be the trait that underlies both physical activity levels and leanness. We identified one potential mechanism for the lean, active phenotype in rats, namely high levels of skeletal muscle PEPCK. Therefore, the lean phenotype is characterized by high endurance capacity and high activity and may stem from altered skeletal muscle energetics.

  6. Impact of physical size on gefitinib efficacy in patients with non-small cell lung cancer harboring EGFR mutations.

    Science.gov (United States)

    Ichihara, Eiki; Hotta, Katsuyuki; Takigawa, Nagio; Kudo, Kenichiro; Kato, Yuka; Honda, Yoshihiro; Hayakawa, Hiromi; Minami, Daisuke; Sato, Akiko; Tabata, Masahiro; Tanimoto, Mitsune; Kiura, Katsuyuki

    2013-09-01

    Gefitinib is an essential drug for the treatment of non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) gene mutations. The approved dosage is 250 mg/body/day without adjustment for physical size such as body surface area (BSA), and the impact of physical size on the efficacy of gefitinib has not been evaluated. Here, we sought to clarify this issue using a retrospective cohort. We reviewed the medical records of patients with consecutive advanced NSCLC harboring EGFR mutations who underwent gefitinib monotherapy at Okayama University Hospital. In total, 101 patients were included in this study, and the median BSA in this cohort was 1.5 m(2). The median progression-free survival (PFS) of the patients with higher BSA (≥1.5 m(2)) was significantly worse than that of those with lower BSA (BSA on PFS (hazards ratio, 2.34; 95% confidence interval, 1.78-2.89; p = 0.002). By contrast, no significant association between BSA and PFS was observed in those undergoing cytotoxic chemotherapy (4.0 vs. 5.1 months; p = 0.989, log-rank test), suggesting that BSA is a predictive, rather than a prognostic, marker for gefitinib therapy in EGFR-mutated NSCLC. In conclusion, BSA affected PFS in patients with EGFR-mutated NSCLC who underwent gefitinib monotherapy, suggesting the need for appraisal of BSA-based dose adjustment, even for this molecular target-based therapy.

  7. Usage of Parameterized Fatigue Spectra and Physics-Based Systems Engineering Models for Wind Turbine Component Sizing: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, Taylor; Guo, Yi; Veers, Paul; Dykes, Katherine; Damiani, Rick

    2016-01-26

    Software models that use design-level input variables and physics-based engineering analysis for estimating the mass and geometrical properties of components in large-scale machinery can be very useful for analyzing design trade-offs in complex systems. This study uses DriveSE, an OpenMDAO-based drivetrain model that uses stress and deflection criteria to size drivetrain components within a geared, upwind wind turbine. Because a full lifetime fatigue load spectrum can only be defined using computationally-expensive simulations in programs such as FAST, a parameterized fatigue loads spectrum that depends on wind conditions, rotor diameter, and turbine design life has been implemented. The parameterized fatigue spectrum is only used in this paper to demonstrate the proposed fatigue analysis approach. This paper details a three-part investigation of the parameterized approach and a comparison of the DriveSE model with and without fatigue analysis on the main shaft system. It compares loads from three turbines of varying size and determines if and when fatigue governs drivetrain sizing compared to extreme load-driven design. It also investigates the model's sensitivity to shaft material parameters. The intent of this paper is to demonstrate how fatigue considerations in addition to extreme loads can be brought into a system engineering optimization.

  8. Free volume hole size of Cyanate ester resin/Epoxy resin interpenetrating networks and its correlations with physical properties

    Energy Technology Data Exchange (ETDEWEB)

    Zeng Minfeng [Institute of Applied Chemistry, Shaoxing University, Shaoxing 312000 (China); Lu Cuiyun [Institute of Applied Chemistry, Shaoxing University, Shaoxing 312000 (China); Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004 (China); Wang Baoyi [Institute of High Energy Physics, The Chinese Academy of Science, Beijing 100049 (China); Qi Chenze, E-mail: qichenze@usx.edu.c [Institute of Applied Chemistry, Shaoxing University, Shaoxing 312000 (China)

    2010-09-15

    Cyanate ester (CE) resin was blended with epoxy resin (EP) at different mass ratios (CE/EP: 100/0, 90/10, 70/30, 50/50, 30/70, 10/90, and 0/100). The curing process of the blend system was characterized by Fourier transform infrared spectrometry (FTIR) and differential scanning calorimetry (DSC). Examination of the mechanical properties, thermal stability, and morphology of the blend systems showed that addition of epoxy resin resulted in improved toughness but a little sacrifice in thermal stability when compared with neat CE. The free volume size of the blend system determined by positron annihilation lifetime spectroscopy (PALS) decreased with the epoxy resin content, which is consistent with the chemical structure changes for the copolymerization between CE and EP. The crosslinking units of curing products (oxazoline, oxazolidinone, and polyether network) of the blends are all smaller in size than those of triazine ring structure from neat CE. Therefore, the free volume size of the blends decreases with increase of EP content. The correlations between the free volume properties and other physical properties (thermal stability and mechanical properties) have also been discussed.

  9. Derivation of Physical and Optical Properties of Midlatitude Cirrus Ice Crystals for a Size-Resolved Cloud Microphysics Model

    Science.gov (United States)

    Fridlind, Ann M.; Atlas, Rachel; Van Diedenhoven, Bastiaan; Um, Junshik; McFarquhar, Greg M.; Ackerman, Andrew S.; Moyer, Elisabeth J.; Lawson, R. Paul

    2016-01-01

    Single-crystal images collected in mid-latitude cirrus are analyzed to provide internally consistent ice physical and optical properties for a size-resolved cloud microphysics model, including single-particle mass, projected area, fall speed, capacitance, single-scattering albedo, and asymmetry parameter. Using measurements gathered during two flights through a widespread synoptic cirrus shield, bullet rosettes are found to be the dominant identifiable habit among ice crystals with maximum dimension (Dmax) greater than 100µm. Properties are therefore first derived for bullet rosettes based on measurements of arm lengths and widths, then for aggregates of bullet rosettes and for unclassified (irregular) crystals. Derived bullet rosette masses are substantially greater than reported in existing literature, whereas measured projected areas are similar or lesser, resulting in factors of 1.5-2 greater fall speeds, and, in the limit of large Dmax, near-infrared single-scattering albedo and asymmetry parameter (g) greater by approx. 0.2 and 0.05, respectively. A model that includes commonly imaged side plane growth on bullet rosettes exhibits relatively little difference in microphysical and optical properties aside from approx. 0:05 increase in mid-visible g primarily attributable to plate aspect ratio. In parcel simulations, ice size distribution, and g are sensitive to assumed ice properties.

  10. Scaling stellar feedback: A study of the physical processes involved in star-forming regions of vastly different sizes

    Science.gov (United States)

    Pellegrini, Eric W.

    2009-09-01

    Regions of recent or ongoing star formation often contain massive stars capable of ionizing the surfaces of nearby molecular clouds. These layers of ionized gas, called H II regions, produce emission lines that serve as beacons of star formation as we look out into distant parts of our Galaxy and the universe. The complex physical processes of star formation are responsible for the chemical and structural evolution of galaxies throughout the history of the universe on many size scales. Light and winds from massive stars heat and compress nearby clouds, acting to simultaneously inhibit and enhance further star formation. To disentangle the importance of competing processes such as photoionization, supernovae, stellar winds, magnetic fields, radiation pressure, I have studied the dominant physical processes in nearby H II regions to determine the relative contribution of each feedback mechanism as a function of star formation intensity. The Orion Nebula is an H II region that is visible to the naked eye. Due to its proximity to the Sun and brightness, it has been studied extensively in all wavelengths. It is dominated by a single O star and offers the least complex environment to compare with models of H II regions. The most complex site of star formation in the local universe is 30 Doradus in the Large Magellanic Cloud. Hundreds of O stars dominated a region thousands of times larger than the Orion Nebula. Together these two examples provide the constraints necessary to quantify stellar feedback on different scales.

  11. Does activity space size influence physical activity levels of adolescents?—A GPS study of an urban environment

    Science.gov (United States)

    Lee, Nolan C.; Voss, Christine; Frazer, Amanda D.; Hirsch, Jana A.; McKay, Heather A.; Winters, Meghan

    2015-01-01

    Background Physical activity (PA) is closely linked with child and youth health, and active travel may be a solution to enhancing PA levels. Activity spaces depict the geographic coverage of one's travel. Little is known about activity spaces and PA in adolescents. Objective To explore the relation between adolescent travel (using a spatial measure of activity space size) and daily moderate-to-vigorous PA (MVPA), with a focus on school days. Methods We used Global Positioning Systems to manually identify trips and generate activity spaces for each person-day; quantified by area for 39 students (13.8 ± 0.6 years, 38% female) attending high school in urban Downtown Vancouver, Canada. We assessed the association between activity space area and MVPA using multi-level regression. We calculated total, school-day and trip-based MVPA for each valid person-day (accelerometry; ≥ 600 min wear time). Results On school days, students accrued 68.2 min/day (95% CI 60.4–76.0) of MVPA. Daily activity spaces averaged 2.2 km2 (95% CI 1.3–3.0). There was no association between activity space size and school-day MVPA. Students accrued 21.8 min/day (95% CI 19.2–24.4) of MVPA during school hours, 19.4 min/day (95% CI 15.1–23.7) during travel, and 28.3 min/day (95% CI 22.3–34.3) elsewhere. Conclusion School and school travel are important sources of PA in Vancouver adolescents, irrespective of activity space area covered. PMID:26807349

  12. Microstructure evolution at the onset of discontinuous dynamic recrystallization: A physics-based model of subgrain critical size

    Energy Technology Data Exchange (ETDEWEB)

    Momeni, A., E-mail: ammomeni@aut.ac.ir [Department of Materials Science and Engineering, Hamedan University of Technology, Hamedan (Iran, Islamic Republic of); Ebrahimi, G.R. [Department of Materials and Polymer Engineering, Faculty of Engineering, Hakim Sabzevari University, Sabzevar (Iran, Islamic Republic of); Jahazi, M.; Bocher, P. [Département de Génie Mécanique, École de Technologie Supérieure, Montréal, QC (Canada)

    2014-02-25

    Highlights: • Evolution of subgrains to recrystallization nuclei is possible at very low strains. • Dynamic recrystallization nuclei increases on a sigmoidal curve with strain. • Nucleation rate increases up to a maximum and decreases to zero at peak strain. • Growth of recrystallized nuclei diminishes to zero at or over the peak. • Site saturation is the mechanism of dynamic recrystallization up to the peak. -- Abstract: A physical model based on the evolution of subgrains size is proposed to describe the nucleation and growth processes during discontinuous dynamic recrystallization. The evolution of subgrains to viable recrystallization nuclei was found possible at very low strains. Afterwards, the number of stable nuclei considerably increased on a sigmoidal trend with strain and reached a saturated state at about 0.6 times the peak strain. The dependence of nucleation rate on strain was modeled using an Avrami-type equation and the driving force for the growth of recrystallized nuclei was similarly modeled in terms of strain. It is also shown that “site saturation” is the governing mechanism for the initiation of the discontinues dynamic recrystallization at the grain boundaries. The flow stress of the material was calculated using the law of mixture of recrystallized and unrecrystallized regions with fractional softening as the stress-partitioning factor. Satisfactory agreement between predicted and experimental results was obtained, thereby confirming the validity of the proposed model.

  13. Comparison of Hounsfield units by changing in size of physical area and setting size of region of interest by using the CT phantom made with a 3D printer

    Energy Technology Data Exchange (ETDEWEB)

    Seung, Youl Hun [Dept. of Radiological Science, Cheongju University, Cheongju (Korea, Republic of)

    2015-12-15

    In this study, we have observed the change of the Hounsfield (HU) in the alteration of by changing in size of physical area and setting size of region of interest (ROI) at focus on kVp and mAs. Four-channel multi-detector computed tomography was used to get transverse axial scanning images and HU. Three dimensional printer which is type of fused deposition modeling (FDM) was used to produce the Phantom. The structure of the phantom was designed to be a type of cylinder that contains 33 mm, 24 mm, 19 mm, 16 mm, 9 mm size of circle holes that are symmetrically located. It was charged with mixing iodine contrast agent and distilled water in the holes. The images were gained with changing by 90 kVp, 120 kVp, 140 kVp and 50 mAs, 100 mAs, 150 mAs, respectively. The ‘image J’ was used to get the HU measurement of gained images of ROI. As a result, it was confirmed that kVp affects to HU more than mAs. And it is suggested that the smaller size of physical area, the more decreasing HU even in material of a uniform density and the smaller setting size of ROI, the more increasing HU. Therefore, it is reason that to set maximum ROI within 5 HU is the best way to minimize in the alteration of by changing in size of physical area and setting size of region of interest.

  14. PHYSICS

    CERN Multimedia

    P. Sphicas

    There have been three physics meetings since the last CMS week: “physics days” on March 27-29, the Physics/ Trigger week on April 23-27 and the most recent physics days on May 22-24. The main purpose of the March physics days was to finalize the list of “2007 analyses”, i.e. the few topics that the physics groups will concentrate on for the rest of this calendar year. The idea is to carry out a full physics exercise, with CMSSW, for select physics channels which test key features of the physics objects, or represent potential “day 1” physics topics that need to be addressed in advance. The list of these analyses was indeed completed and presented in the plenary meetings. As always, a significant amount of time was also spent in reviewing the status of the physics objects (reconstruction) as well as their usage in the High-Level Trigger (HLT). The major event of the past three months was the first “Physics/Trigger week” in Apri...

  15. PHYSICS

    CERN Multimedia

    D. Acosta

    2010-01-01

    A remarkable amount of progress has been made in Physics since the last CMS Week in June given the exponential growth in the delivered LHC luminosity. The first major milestone was the delivery of a variety of results to the ICHEP international conference held in Paris this July. For this conference, CMS prepared 15 Physics Analysis Summaries on physics objects and 22 Summaries on new and interesting physics measurements that exploited the luminosity recorded by the CMS detector. The challenge was incorporating the largest batch of luminosity that was delivered only days before the conference (300 nb-1 total). The physics covered from this initial running period spanned hadron production measurements, jet production and properties, electroweak vector boson production, and even glimpses of the top quark. Since then, the accumulated integrated luminosity has increased by a factor of more than 100, and all groups have been working tremendously hard on analysing this dataset. The September Physics Week was held ...

  16. Effect of particle size and particle size distribution on physical characteristics, morphology and crystal structure of explosively compacted high-T(sub c) superconductors

    Science.gov (United States)

    Kotsis, I.; Enisz, M.; Oravetz, D.; Szalay, A.

    1995-01-01

    A superconductor, of composition Y(Ba,K,Na)2Cu3O(x)/F(y) and a composite of composition Y(Ba,K,Na)2Cu3O(x)/F(y) + Ag, with changing K, Na and F content but a constant silver content (Ag = 10 mass%) was prepared using a single heat treatment. the resulting material was ground in a corundum lined mill, separated to particle size fractions of 0-40 micron, 0-63 micron and 63-900 micron and explosively compacted, using an explosive pressure of 10(exp 4) MPa and a subsequent heat treatment. Best results were obtained with the 63-900 micron fraction of composition Y(Ba(1.95) K(0.01)Cu3O(x)F(0),(05)/Ag: porosity less than 0.01 cu cm/g and current density 2800 A/sq cm at 77K.

  17. PHYSICS

    CERN Multimedia

    P. Sphicas

    The CPT project came to an end in December 2006 and its original scope is now shared among three new areas, namely Computing, Offline and Physics. In the physics area the basic change with respect to the previous system (where the PRS groups were charged with detector and physics object reconstruction and physics analysis) was the split of the detector PRS groups (the old ECAL-egamma, HCAL-jetMET, Tracker-btau and Muons) into two groups each: a Detector Performance Group (DPG) and a Physics Object Group. The DPGs are now led by the Commissioning and Run Coordinator deputy (Darin Acosta) and will appear in the correspond¬ing column in CMS bulletins. On the physics side, the physics object groups are charged with the reconstruction of physics objects, the tuning of the simulation (in collaboration with the DPGs) to reproduce the data, the provision of code for the High-Level Trigger, the optimization of the algorithms involved for the different physics analyses (in collaboration with the analysis gr...

  18. PHYSICS

    CERN Multimedia

    J. Incandela

    There have been numerous developments in the physics area since the September CMS week. The biggest single event was the Physics/Trigger week in the end of Octo¬ber, whereas in terms of ongoing activities the “2007 analyses” went into high gear. This was in parallel with participation in CSA07 by the physics groups. On the or¬ganizational side, the new conveners of the physics groups have been selected, and a new database for man¬aging physics analyses has been deployed. Physics/Trigger week The second Physics-Trigger week of 2007 took place during the week of October 22-26. The first half of the week was dedicated to working group meetings. The ple¬nary Joint Physics-Trigger meeting took place on Wednesday afternoon and focused on the activities of the new Trigger Studies Group (TSG) and trigger monitoring. Both the Physics and Trigger organizations are now focused on readiness for early data-taking. Thus, early trigger tables and preparations for calibr...

  19. Typical food portion sizes consumed by Australian adults: results from the 2011-12 Australian National Nutrition and Physical Activity Survey.

    Science.gov (United States)

    Zheng, Miaobing; Wu, Jason H Y; Louie, Jimmy Chun Yu; Flood, Victoria M; Gill, Tim; Thomas, Beth; Cleanthous, Xenia; Neal, Bruce; Rangan, Anna

    2016-01-01

    Considerable evidence has associated increasing portion sizes with elevated obesity prevalence. This study examines typical portion sizes of commonly consumed core and discretionary foods in Australian adults, and compares these data with the Australian Dietary Guidelines standard serves. Typical portion sizes are defined as the median amount of foods consumed per eating occasion. Sex- and age-specific median portion sizes of adults aged 19 years and over (n = 9341) were analysed using one day 24 hour recall data from the 2011-12 National Nutrition and Physical Activity Survey. A total of 152 food categories were examined. There were significant sex and age differences in typical portion sizes among a large proportion of food categories studied. Typical portion sizes of breads and cereals, meat and chicken cuts, and starchy vegetables were 30-160% larger than the standard serves, whereas, the portion sizes of dairy products, some fruits, and non-starchy vegetables were 30-90% smaller. Typical portion sizes for discretionary foods such as cakes, ice-cream, sausages, hamburgers, pizza, and alcoholic drinks exceeded the standard serves by 40-400%. The findings of the present study are particularly relevant for establishing Australian-specific reference portions for dietary assessment tools, refinement of nutrition labelling and public health policies. PMID:26786684

  20. PHYSICS

    CERN Multimedia

    Submitted by

    Physics Week: plenary meeting on physics groups plans for startup (14–15 May 2008) The Physics Objects (POG) and Physics Analysis (PAG) Groups presented their latest developments at the plenary meeting during the Physics Week. In the presentations particular attention was given to startup plans and readiness for data-taking. Many results based on the recent cosmic run were shown. A special Workshop on SUSY, described in a separate section, took place the day before the plenary. At the meeting, we had also two special DPG presentations on “Tracker and Muon alignment with CRAFT” (Ernesto Migliore) and “Calorimeter studies with CRAFT” (Chiara Rovelli). We had also a report from Offline (Andrea Rizzi) and Computing (Markus Klute) on the San Diego Workshop, described elsewhere in this bulletin. Tracking group (Boris Mangano). The level of sophistication of the tracking software increased significantly over the last few months: V0 (K0 and Λ) reconstr...

  1. Effect of particle size and particle size distribution on physical characteristics, morphology and crystal strucutre of explosively compacted high-Tc superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Kotsis, I.; Enisz, M.; Oravetz, D. [Univ. of Veszprem (Hungary)] [and others

    1994-12-31

    A superconductor, of composition Y(Ba,K,Na){sub 2}Cu{sub 3}O{sub x}/F{sub y} and a composite, of composition Y(Ba,K,Na){sub 2}Cu{sub 3}O{sub x}/F{sub y}+Ag, with changing K, Na and F content, but a constant silver content (Ag=10 mass per cent) was prepared using a single heat treatment. The resulting material was ground in a corundum lined mill, separated to particle size fractions of 0-40 {mu}m, 0-63 {mu}m and 63-900 {mu}m and explosively compacted, using an explosive pressure of 10{sup 4} MPa and a subsequent heat treatment. Best results were obtained with the 63-900 {mu}m fraction of composition Y(Ba{sub 1,95}K{sub 0,01})Cu{sub 3}O{sub x}F{sub 0,05}/Ag: porosity <0.01 cm{sup 3}/g and current density 2800 A/cm{sup 2} at 77 K.

  2. Relations among Body Size Discrepancy, Gender, and Indices of Motivation and Achievement in High School Physical Education

    Science.gov (United States)

    Lodewyk, Ken R.; Gammage, Kimberley L.; Sullivan, Philip J.

    2009-01-01

    Increasing dropout rates in senior high school physical education, particularly among females, and unhealthy activity and obesity levels in youth have led to recommendations to assess potential contributing factors in physical education participation. Drawing from gender, body image, and social-cognitive theory, this study investigated relations…

  3. Impact of body size and physical activity during adolescence and adult life on overall and cause-specific mortality in a large cohort study from Iran.

    Science.gov (United States)

    Etemadi, Arash; Abnet, Christian C; Kamangar, Farin; Islami, Farhad; Khademi, Hooman; Pourshams, Akram; Poustchi, Hossein; Bagheri, Mohammad; Sohrabpour, Amir Ali; Aliasgar, Ali; Khoshnia, Masoud; Wacholder, Sholom; Matthews, Charles C; Pharoah, Paul D; Brennan, Paul; Boffetta, Paolo; Malekzadeh, Reza; Dawsey, Sanford M

    2014-02-01

    We conducted this study to examine life-course body size and physical activity in relation to total and cause-specific mortality, which has not previously been studied in the low and middle-income countries in Asia. The Golestan Cohort Study is a population-based cohort in northeastern Iran in which 50,045 people above the age of 40 have been followed since 2004. Participants were shown a validated pictogram to assess body size at ages 15, 30, and the time of recruitment. Information on occupational physical activity at these ages was also collected. Subjects were followed up annually, and cause of death was determined. Cox regression models were adjusted for age at cohort start, smoking, socioeconomic status, ethnicity, place of residence, education, and opium use. Models for body size were also adjusted for physical activity at the same age, and vice versa. During a total of 252,740 person-years of follow-up (mean follow-up duration 5.1 ± 1.3 years) through December 2011, 2,529 of the cohort participants died. Larger body sizes at ages 15 or 30 in both sexes were associated with increased overall mortality. Cancer mortality was more strongly associated with adolescent obesity, and cardiovascular mortality with early adulthood body size. Weight gain between these ages was associated with cardiovascular mortality. Obese adolescents who lost weight still had increased mortality from all medical causes in both sexes. Physical activity during adolescence and early adulthood had no association with mortality, but at cohort baseline higher levels of activity were associated with reduced mortality. Mortality in this Middle-Eastern population was associated with obesity both during adolescence and early adult life. PMID:24557643

  4. PHYSICS

    CERN Multimedia

    D. Futyan

    A lot has transpired on the “Physics” front since the last CMS Bulletin. The summer was filled with preparations of new Monte Carlo samples based on CMSSW_3, the finalization of all the 10 TeV physics analyses [in total 50 analyses were approved] and the preparations for the Physics Week in Bologna. A couple weeks later, the “October Exercise” commenced and ran through an intense two-week period. The Physics Days in October were packed with a number of topics that are relevant to data taking, in a number of “mini-workshops”: the luminosity measurement, the determination of the beam spot and the measurement of the missing transverse energy (MET) were the three main topics.   Physics Week in Bologna The second physics week in 2009 took place in Bologna, Italy, on the week of Sep 7-11. The aim of the week was to review and establish (we hoped) the readiness of CMS to do physics with the early collisions at the LHC. The agenda of the...

  5. PHYSICS

    CERN Multimedia

    D. Futyan

    A lot has transpired on the “Physics” front since the last CMS Bulletin. The summer was filled with preparations of new Monte Carlo samples based on CMSSW_3, the finalization of all the 10 TeV physics analyses [in total 50 analyses were approved] and the preparations for the Physics Week in Bologna. A couple weeks later, the “October Exercise” commenced and ran through an intense two-week period. The Physics Days in October were packed with a number of topics that are relevant to data taking, in a number of “mini-workshops”: the luminosity measurement, the determination of the beam spot and the measurement of the missing transverse energy (MET) were the three main topics.  Physics Week in Bologna The second physics week in 2009 took place in Bologna, Italy, on the week of Sep 7-11. The aim of the week was to review and establish how ready we are to do physics with the early collisions at the LHC. The agenda of the week was thus pac...

  6. Estimation of Pore Size Distribution by CO2 Adsorption and Its Application in Physical Activation of Precursors

    Institute of Scientific and Technical Information of China (English)

    周理; 姚金花; 王瑜

    2000-01-01

    The CO2 adsorption data may show more than one section in the Dubinin-Radushkevich-Kaganer(DRK) plot if samples had been over-activated. Each section in the plot represents a range of pore size. The whole DRK plot provided information on the pore size distribution(PSD) of a sample, which may be used to monitor the effect of activation conditions in activation processes.

  7. PHYSICS

    CERN Multimedia

    Joe Incandela

    There have been two plenary physics meetings since the December CMS week. The year started with two workshops, one on the measurements of the Standard Model necessary for “discovery physics” as well as one on the Physics Analysis Toolkit (PAT). Meanwhile the tail of the “2007 analyses” is going through the last steps of approval. It is expected that by the end of January all analyses will have converted to using the data from CSA07 – which include the effects of miscalibration and misalignment. January Physics Days The first Physics Days of 2008 took place on January 22-24. The first two days were devoted to comprehensive re¬ports from the Detector Performance Groups (DPG) and Physics Objects Groups (POG) on their planning and readiness for early data-taking followed by approvals of several recent studies. Highlights of POG presentations are included below while the activities of the DPGs are covered elsewhere in this bulletin. January 24th was devo...

  8. PHYSICS

    CERN Multimedia

    J. Incandela

    The all-plenary format of the CMS week in Cyprus gave the opportunity to the conveners of the physics groups to present the plans of each physics analysis group for tackling early physics analyses. The presentations were complete, so all are encouraged to browse through them on the Web. There is a wealth of information on what is going on, by whom and on what basis and priority. The CMS week was followed by two CMS “physics events”, the ICHEP08 days and the physics days in July. These were two weeks dedicated to either the approval of all the results that would be presented at ICHEP08, or to the review of all the other Monte-Carlo based analyses that were carried out in the context of our preparations for analysis with the early LHC data (the so-called “2008 analyses”). All this was planned in the context of the beginning of a ramp down of these Monte Carlo efforts, in anticipation of data.  The ICHEP days are described below (agenda and talks at: http://indic...

  9. Physics

    CERN Document Server

    Cullen, Katherine

    2005-01-01

    Defined as the scientific study of matter and energy, physics explains how all matter behaves. Separated into modern and classical physics, the study attracts both experimental and theoretical physicists. From the discovery of the process of nuclear fission to an explanation of the nature of light, from the theory of special relativity to advancements made in particle physics, this volume profiles 10 pioneers who overcame tremendous odds to make significant breakthroughs in this heavily studied branch of science. Each chapter contains relevant information on the scientist''s childhood, research, discoveries, and lasting contributions to the field and concludes with a chronology and a list of print and Internet references specific to that individual.

  10. PHYSICS

    CERN Multimedia

    Chris Hill

    2012-01-01

    The months that have passed since the last CMS Bulletin have been a very busy and exciting time for CMS physics. We have gone from observing the very first 8TeV collisions produced by the LHC to collecting a dataset of the collisions that already exceeds that recorded in all of 2011. All in just a few months! Meanwhile, the analysis of the 2011 dataset and publication of the subsequent results has continued. These results come from all the PAGs in CMS, including searches for the Higgs boson and other new phenomena, that have set the most stringent limits on an ever increasing number of models of physics beyond the Standard Model including dark matter, Supersymmetry, and TeV-scale gravity scenarios, top-quark physics where CMS has overtaken the Tevatron in the precision of some measurements, and bottom-quark physics where CMS made its first discovery of a new particle, the Ξ*0b baryon (candidate event pictured below). Image 2:  A Ξ*0b candidate event At the same time POGs and PAGs...

  11. PHYSICS

    CERN Multimedia

    Guenther Dissertori

    The time period between the last CMS week and this June was one of intense activity with numerous get-together targeted at addressing specific issues on the road to data-taking. The two series of workshops, namely the “En route to discoveries” series and the “Vertical Integration” meetings continued.   The first meeting of the “En route to discoveries” sequence (end 2007) had covered the measurements of the Standard Model signals as necessary prerequisite to any claim of signals beyond the Standard Model. The second meeting took place during the Feb CMS week and concentrated on the commissioning of the Physics Objects, whereas the third occurred during the April Physics Week – and this time the theme was the strategy for key new physics signatures. Both of these workshops are summarized below. The vertical integration meetings also continued, with two DPG-physics get-togethers on jets and missing ET and on electrons and photons. ...

  12. PHYSICS

    CERN Multimedia

    D. Acosta

    2011-01-01

    Since the last CMS Week, all physics groups have been extremely active on analyses based on the full 2010 dataset, with most aiming for a preliminary measurement in time for the winter conferences. Nearly 50 analyses were approved in a “marathon” of approval meetings during the first two weeks of March, and the total number of approved analyses reached 90. The diversity of topics is very broad, including precision QCD, Top, and electroweak measurements, the first observation of single Top production at the LHC, the first limits on Higgs production at the LHC including the di-tau final state, and comprehensive searches for new physics in a wide range of topologies (so far all with null results unfortunately). Most of the results are based on the full 2010 pp data sample, which corresponds to 36 pb-1 at √s = 7 TeV. This report can only give a few of the highlights of a very rich physics program, which is listed below by physics group...

  13. Influence of Substrate Particle Size and Wet Oxidation on Physical Surface Structures and Enzymatic Hydrolysis of Wheat Straw

    DEFF Research Database (Denmark)

    Pedersen, Mads; Meyer, Anne S.

    2009-01-01

    In the worldwide quest for producing biofuels from lignocellulosic biomass, the importance of the substrate pretreatment is becoming increasingly apparent. This work examined the effects of reducing the substrate particle sizes of wheat straw by grinding prior to wet oxidation and enzymatic hydro...... a significant amount of solid, apparently porous structures within all particles size groups of both the not wet oxidized and wet oxidized particles. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009.......In the worldwide quest for producing biofuels from lignocellulosic biomass, the importance of the substrate pretreatment is becoming increasingly apparent. This work examined the effects of reducing the substrate particle sizes of wheat straw by grinding prior to wet oxidation and enzymatic...... with reduced particle size. After wet oxidation, the glucose release from the smallest particles (53-149 m) reached 90% of the theoretical maximum after 24 h of enzyme treatment. The corresponding glucose release from the wet oxidized reference samples (2-4 cm) was 65% of the theoretical maximum. The xylose...

  14. The Relationship with Balance, Foot Posture, and Foot Size in School of Physical Education and Sports Students

    Science.gov (United States)

    Irez, Gonul Babayigit

    2014-01-01

    The aim of this study is to investigate the relationship of foot posture and foot size with balance. A hundred and thirteen healthy volunteers were recruited from undergraduate students (Male = 74, Female = 37, age range 18-22). The Foot Posture Index (FPI-6), anthropometric measurements, dynamic balance and static balance measurements were done…

  15. PHYSICS

    CERN Multimedia

    C. Hill

    2012-01-01

      The period since the last CMS Bulletin has been historic for CMS Physics. The pinnacle of our physics programme was an observation of a new particle – a strong candidate for a Higgs boson – which has captured worldwide interest and made a profound impact on the very field of particle physics. At the time of the discovery announcement on 4 July, 2012, prominent signals were observed in the high-resolution H→γγ and H→ZZ(4l) modes. Corroborating excess was observed in the H→W+W– mode as well. The fermionic channel analyses (H→bb, H→ττ), however, yielded less than the Standard Model (SM) expectation. Collectively, the five channels established the signal with a significance of five standard deviations. With the exception of the diphoton channel, these analyses have all been updated in the last months and several new channels have been added. With improved analyses and more than twice the i...

  16. PHYSICS

    CERN Multimedia

    D. Acosta

    2010-01-01

    The Physics Groups are actively engaged on analyses of the first data from the LHC at 7 TeV, targeting many results for the ICHEP conference taking place in Paris this summer. The first large batch of physics approvals is scheduled for this CMS Week, to be followed by four more weeks of approvals and analysis updates leading to the start of the conference in July. Several high priority analysis areas were organized into task forces to ensure sufficient coverage from the relevant detector, object, and analysis groups in the preparation of these analyses. Already some results on charged particle correlations and multiplicities in 7 TeV minimum bias collisions have been approved. Only one small detail remains before ICHEP: further integrated luminosity delivered by the LHC! Beyond the Standard Model measurements that can be done with these data, the focus changes to the search for new physics at the TeV scale and for the Higgs boson in the period after ICHEP. Particle Flow The PFT group is focusing on the ...

  17. PHYSICS

    CERN Multimedia

    Darin Acosta

    2010-01-01

    The collisions last year at 900 GeV and 2.36 TeV provided the long anticipated collider data to the CMS physics groups. Quite a lot has been accomplished in a very short time. Although the delivered luminosity was small, CMS was able to publish its first physics paper (with several more in preparation), and commence the commissioning of physics objects for future analyses. Many new performance results have been approved in advance of this CMS Week. One remarkable outcome has been the amazing agreement between out-of-the-box data with simulation at these low energies so early in the commissioning of the experiment. All of this is testament to the hard work and preparation conducted beforehand by many people in CMS. These analyses could not have happened without the dedicated work of the full collaboration on building and commissioning the detector, computing, and software systems combined with the tireless work of many to collect, calibrate and understand the data and our detector. To facilitate the efficien...

  18. PHYSICS

    CERN Multimedia

    C. Hill

    2012-01-01

      2012 has started off as a very busy year for the CMS Physics Groups. Planning for the upcoming higher luminosity/higher energy (8 TeV) operation of the LHC and relatively early Rencontres de Moriond are the high-priority activities for the group at the moment. To be ready for the coming 8-TeV data, CMS has made a concerted effort to perform and publish analyses on the 5 fb−1 dataset recorded in 2011. This has resulted in the submission of 16 papers already, including nine on the search for the Higgs boson. In addition, a number of preliminary results on the 2011 dataset have been released to the public. The Exotica and SUSY groups approved several searches for new physics in January, such as searches for W′ and exotic highly ionising particles. These were highlighted at a CERN seminar given on 24th  January. Many more analyses, from all the PAGs, including the newly formed SMP (Standard Model Physics) and FSQ (Forward and Small-x QCD), were approved in February. The ...

  19. PHYSICS

    CERN Multimedia

    L. Demortier

    Physics-wise, the CMS week in December was dominated by discussions of the analyses that will be carried out in the “next six months”, i.e. while waiting for the first LHC collisions.  As presented in December, analysis approvals based on Monte Carlo simulation were re-opened, with the caveat that for this work to be helpful to the goals of CMS, it should be carried out using the new software (CMSSW_2_X) and associated samples.  By the end of the week, the goal for the physics groups was set to be the porting of our physics commissioning methods and plans, as well as the early analyses (based an integrated luminosity in the range 10-100pb-1) into this new software. Since December, the large data samples from CMSSW_2_1 were completed. A big effort by the production group gave a significant number of events over the end-of-year break – but also gave out the first samples with the fast simulation. Meanwhile, as mentioned in December, the arrival of 2_2 meant that ...

  20. PHYSICS

    CERN Multimedia

    the PAG conveners

    2011-01-01

    The delivered LHC integrated luminosity of more than 1 inverse femtobarn by summer and more than 5 by the end of 2011 has been a gold mine for the physics groups. With 2011 data, we have submitted or published 14 papers, 7 others are in collaboration-wide review, and 75 Physics Analysis Summaries have been approved already. They add to the 73 papers already published based on the 2010 and 2009 datasets. Highlights from each physics analysis group are described below. Heavy ions Many important results have been obtained from the first lead-ion collision run in 2010. The published measurements include the first ever indications of Υ excited state suppression (PRL synopsis), long-range correlation in PbPb, and track multiplicity over a wide η range. Preliminary results include the first ever measurement of isolated photons (showing no modification), J/ψ suppression including the separation of the non-prompt component, further study of jet fragmentation, nuclear modification factor...

  1. Sizing up microbes

    OpenAIRE

    Viswanathan, V. K.

    2012-01-01

    The size range of life forms is dictated by basic principles of physics. Large microorganisms, with sizes approaching a millimeter, have compensating features that address the immutable laws of physics. For pathogens, size may impact a range of functions, such as adherence and immune evasion. We review several recent studies on factors impacting, and impacted by, the size of microorganisms.

  2. Effect of rock mass structure and block size on the slope stability--Physical modeling and discrete element simulation

    Institute of Scientific and Technical Information of China (English)

    LI; Shihai; LIAN; Zhenzhong; J.; G.; Wang

    2005-01-01

    This paper studies the stability of jointed rock slopes by using our improved three-dimensional discrete element methods (DEM) and physical modeling. Results show that the DEM can simulate all failure modes of rock slopes with different joint configurations. The stress in each rock block is not homogeneous and blocks rotate in failure development. Failure modes depend on the configuration of joints. Toppling failure is observed for the slope with straight joints and sliding failure is observed for the slope with staged joints. The DEM results are also compared with those of limit equilibrium method (LEM). Without considering the joints in rock masses, the LEM predicts much higher factor of safety than physical modeling and DEM. The failure mode and factor of safety predicted by the DEM are in good agreement with laboratory tests for any jointed rock slope.

  3. The use of a pocket-sized ultrasound device improves physical examination: results of an in- and outpatient cohort study.

    Directory of Open Access Journals (Sweden)

    Agostino Colli

    Full Text Available The performance of pocket mobile ultrasound devices (PUDs is comparable with that of standard ultrasonography, whereas the accuracy of a physical examination is often poor requiring further tests to assess diagnostic hypotheses. Adding the use of PUD to physical examination could lead to an incremental benefit.We assessed whether the use of PUD in the context of physical examination can reduce the prescription of additional tests when used by physicians in different clinical settings.We conducted a cohort impact study in four hospital medical wards, one gastroenterological outpatient clinic, and 90 general practices in the same geographical area. The study involved 135 physicians who used PUD, after a short predefined training course, to examine 1962 consecutive patients with one of 10 diagnostic hypotheses: ascites, pleural effusion, pericardial effusion, urinary retention, urinary stones, gallstones, biliary-duct dilation, splenomegaly, abdominal mass, abdominal aortic aneurysm. According to the physicians' judgment, PUD examination could rule out or in the diagnostic hypothesis or require further testing; the concordance with the final diagnosis was assessed. The main outcome was the proportion of cases in which additional tests were required after PUD. The PUD diagnostic accuracy was assessed in patients submitted to further testing.The 1962 patients included 37% in-patients, 26% gastroenterology outpatients, 37% from general practices. Further testing after PUD examination was deemed unnecessary in 63%. Only 5% of patients with negative PUD not referred for further testing were classified false negatives with respect to the final diagnosis. In patients undergoing further tests, the sensitivity was 91%, and the specificity 83%.After a simple and short training course, a PUD examination can be used in addition to a physical examination to improve the answer to ten common clinical questions concerning in- and outpatients, and can reduce the

  4. Methodological basement of individual regulation of a size of physical loading at pupil of middle class during basketball lessons.

    Directory of Open Access Journals (Sweden)

    Kozina J.L.

    2011-08-01

    Full Text Available Addressed, theoretically and experimentally proved highly effective, and informative method of subjective control of physical exertion in basketball students. The study involved students 12-13 years old, pupils from different schools of Kharkov (girls. The experiment was conducted on the basis of Camp «Zirka» Krasnograd area during the summer. We simulated the physical education class with basketball, which were carried out 2 times a week, lasted 45 minutes. The total duration of the experiment - 6 weeks. The control group consisted of 12 students, the pilot - 12. The perceived value of the load was determined by the Borg scale, which is a series of numbers from 6 to 20, which correspond to qualitative (verbally the characteristics of the value carried the load. Heart rate was recorded at the end of each exercise palpation method. Adequacy of the subjective method of regulation of physical activity for the problems of the learning process associated with the development of special endurance in basketball.

  5. Effects of the Size of Cosmological N-body Simulations on Physical Quantities – II: Halo Formation and Destruction Rate

    Indian Academy of Sciences (India)

    Jayanti Prasad

    2007-06-01

    In this study we show how errors due to finite box size affect formation and the destruction rate for haloes in cosmological N-body simulations. In an earlier study we gave an analytic prescription of finding the corrections in the mass function. Following the same approach, in this paper we give analytical expressions for corrections in the formation rate, destruction rate and the rate of change in comoving number density, and compute their expected values for the power law ( = -2) and LCDM models.

  6. PHYSICS

    CERN Multimedia

    J. D'Hondt

    The Electroweak and Top Quark Workshop (16-17th of July) A Workshop on Electroweak and Top Quark Physics, dedicated on early measurements, took place on 16th-17th July. We had more than 40 presentations at the Workshop, which was an important milestone for 2007 physics analyses in the EWK and TOP areas. The Standard Model has been tested empirically by many previous experiments. Observables which are nowadays known with high precision will play a major role for data-based CMS calibrations. A typical example is the use of the Z to monitor electron and muon reconstruction in di-lepton inclusive samples. Another example is the use of the W mass as a constraint for di-jets in the kinematic fitting of top-quark events, providing information on the jet energy scale. The predictions of the Standard Model, for what concerns proton collisions at the LHC, are accurate to a level that the production of W/Z and top-quark events can be used as a powerful tool to commission our experiment. On the other hand the measure...

  7. PHYSICS

    CERN Multimedia

    Christopher Hill

    2013-01-01

    Since the last CMS Bulletin, the CMS Physics Analysis Groups have completed more than 70 new analyses, many of which are based on the complete Run 1 dataset. In parallel the Snowmass whitepaper on projected discovery potential of CMS for HL-LHC has been completed, while the ECFA HL-LHC future physics studies has been summarised in a report and nine published benchmark analyses. Run 1 summary studies on b-tag and jet identification, quark-gluon discrimination and boosted topologies have been documented in BTV-13-001 and JME-13-002/005/006, respectively. The new tracking alignment and performance papers are being prepared for submission as well. The Higgs analysis group produced several new results including the search for ttH with H decaying to ZZ, WW, ττ+bb (HIG-13-019/020) where an excess of ~2.5σ is observed in the like-sign di-muon channel, and new searches for high-mass Higgs bosons (HIG-13-022). Search for invisible Higgs decays have also been performed both using the associ...

  8. PHYSICS

    CERN Multimedia

    C. Hill

    2013-01-01

    The period since the last CMS bulletin has seen the end of proton collisions at a centre-of-mass energy 8 TeV, a successful proton-lead collision run at 5 TeV/nucleon, as well as a “reference” proton run at 2.76 TeV. With these final LHC Run 1 datasets in hand, CMS Physics Analysis Groups have been busy analysing these data in preparation for the winter conferences. Moreover, despite the fact that the pp run only concluded in mid-December (and there was consequently less time to complete data analyses), CMS again made a strong showing at the Rencontres de Moriond in La Thuile (EW and QCD) where nearly 40 new results were presented. The highlight of these preliminary results was the eagerly anticipated updated studies of the properties of the Higgs boson discovered in July of last year. Meanwhile, preparations for Run 2 and physics performance studies for Phase 1 and Phase 2 upgrade scenarios are ongoing. The Higgs analysis group produced updated analyses on the full Run 1 dataset (~25 f...

  9. PHYSICS

    CERN Multimedia

    C. Hill

    2013-01-01

    In the period since the last CMS Bulletin, the LHC – and CMS – have entered LS1. During this time, CMS Physics Analysis Groups have performed more than 40 new analyses, many of which are based on the complete 8 TeV dataset delivered by the LHC in 2012 (and in some cases on the full Run 1 dataset). These results were shown at, and well received by, several high-profile conferences in the spring of 2013, including the inaugural meeting of the Large Hadron Collider    Physics Conference (LHCP) in Barcelona, and the 26th International Symposium on Lepton Photon Interactions at High Energies (LP) in San Francisco. In parallel, there have been significant developments in preparations for Run 2 of the LHC and on “future physics” studies for both Phase 1 and Phase 2 upgrades of the CMS detector. The Higgs analysis group produced five new results for LHCP including a new H-to-bb search in VBF production (HIG-13-011), ttH with H to γ&ga...

  10. "allometry" Deterministic Approaches in Cell Size, Cell Number and Crude Fiber Content Related to the Physical Quality of Kangkong (Ipomoea reptans) Grown Under Different Plant Density Pressures

    Science.gov (United States)

    Selamat, A.; Atiman, S. A.; Puteh, A.; Abdullah, N. A. P.; Mohamed, M. T. M.; Zulkeefli, A. A.; Othman, S.

    Kangkong, especially the upland type (Ipomoea reptans) is popularly consumed as a vegetable dish in the South East Asian countries for its quality related to Vitamins (A and C) and crude fiber contents. Higher fiber contents would prevent from the occurrence of colon cancer and diverticular disease. With young stem edible portion, its cell number and size contribute to the stem crude fiber content. The mathematical approach of allometry of cell size, number, and fiber content of stem could be used in determining the 'best' plant density pressure in producing the quality young stem to be consumed. Basically, allometry is the ratio of relative increment (growth or change) rates of two parameters, or the change rate associated to the log of measured variables relationship. Kangkog grown equal or lower than 55 plants m-2 produced bigger individual plant and good quality (physical) kangkong leafy vegetable, but with lower total yield per unit area as compared to those grown at higher densities.

  11. Effect of harvest time and physical form of alfalfa silage on chewing time and particle size distribution in boli, rumen content and faeces

    DEFF Research Database (Denmark)

    Kornfelt, L. F.; Weisbjerg, Martin Riis; Norgaard, P.

    2013-01-01

    The study examined the effects of physical form and harvest time of alfalfa silage on eating and ruminating activity and particle size distribution in feed boli, rumen content and faeces in dry cows. The alfalfa crop was harvested at two stages of growth (early: NDF 37 late: NDF 44% in dry matter.......01), physical form (P time (P feeding late-harvested alfalfa silage. Two peaks on the probability density distribution function...... (DM)), and from each harvest, a chopped (theoretical cutting length: 19 mm) and an unchopped crop was ensiled in bales. The silages were fed restrictively to four rumen cannulated non-lactating Jersey cows (391 +/- 26 kg) in a 434 Latin square design. The cows were fed restrictively 80% of their ad...

  12. Enhancement of physical and hydrological properties of a sandy loam soil via application of different biochar particle sizes during incubation period

    Directory of Open Access Journals (Sweden)

    Leila Esmaeelnejad

    2016-06-01

    Full Text Available In spite of many studies that have been carried out, there is a knowledge-gap as to how different sizes of biochars alter soil properties. Therefore, the main objective of this study was to investigate the effects of different sizes of biochars on soil properties. The biochars were produced at two pyrolysis temperatures (350 and 550°C from two feedstocks (rice husk and apple wood chips. Produced biochars were prepared at two diameters (1-2 mm and <1 mm and mixed with soil at a rate of 2% (w/w. Multiple effects of type, temperature and size of biochars were significant, so as the mixture of soil and finer woodchip biochars produced at 550°C had significant effects on all soil properties. Soil aggregation and stabilization of macro-aggregates, values of mean weight diameter and water stable aggregates were improved due to increased soil organic matter as binding agents and microbial biomass. In addition, plant available water capacity, air capacity, S-index, meso-pores and water retention content were significantly increased compared to control. But, saturated hydraulic conductivity (Ks was reduced due to blockage of pores by biochar particles, reduction of pore throat size and available space for flow and also, high field capacity of biochars. So, application of biochar to soil, especially the finest particles of high-tempered woody biochars, can improve physical and hydrological properties of coarse-textured soils and reduce their water drainage by modification of Ks.

  13. Physically-Based Ground Motion Prediction and Validation A Case Study: Mid-sized Marmara Sea Earthquakes

    Science.gov (United States)

    Mert, A.

    2015-12-01

    In this study we have two main purposes. The first one is to simulate five midsize earthquakes (Mw≈5.0) recorded in the Marmara region, which has a geologically complex and heterogeneous crustal structure. We synthesize ground motion for the full wave train on three components, and applied a 'physics based' solution of earthquake rupture. The simulation methodology is based on the studies by Hutchings et al. (2007), Scognamiglio and Hutchings (2009). For each earthquake, we synthesized seismograms using by 500 different rupture scenarios that were generated by Monte Carlo selection of parameters within the range. Synthetic ground motion is a major challenge for seismic hazard assessment studies. Especially after the adoption of performance-based design approach with the Earthquake resistant design of engineering structures. To compute realistic time histories for different locations around Marmara region can be helpful for engineering design, retrofitting the existing structures, hazard and risk management studies and developing new seismic codes and standards.The second purpose is to validate synthetic seismograms with real seismograms. We follow the methodology presented by Anderson (2003) for validation. This methodology proposes a similarity score based on averages of the quality of fit measuring ground motion characteristics and uses a suite of measurements. Namely, the synthetics are compared to real data by ten representative ground motion criteria. The applicability of Empirical Green's functions methodology and physics based solution of earthquake rupture had been assessed in terms of modeling in complex geologic structure. Because the methodology produces source and site specific synthetic ground motion time histories and goodness-of-fit scores of obtained synthetics is between 'fair' to 'good' range based on Anderson's score, we concluded that it can be tried to produce ground motion that has not previously been recorded during catastrophic earthquake

  14. PHYSICS

    CERN Multimedia

    V.Ciulli

    2011-01-01

    The main programme of the Physics Week held between 16th and 20th May was a series of topology-oriented workshops on di-leptons, di-photons, inclusive W, and all-hadronic final states. The goal of these workshops was to reach a common understanding for the set of objects (ID, cleaning...), the handling of pile-up, calibration, efficiency and purity determination, as well as to revisit critical common issues such as the trigger. Di-lepton workshop Most analysis groups use a di-lepton trigger or a combination of single and di-lepton triggers in 2011. Some groups need to collect leptons with as low PT as possible with strong isolation and identification requirements as for Higgs into WW at low mass, others with intermediate PT values as in Drell-Yan studies, or high PT as in the Exotica group. Electron and muon reconstruction, identification and isolation, was extensively described in the workshop. For electrons, VBTF selection cuts for low PT and HEEP cuts for high PT were discussed, as well as more complex d...

  15. The particle size effect on some physical properties of neodymium cobaltate-manganites for hydrogen storage use

    Science.gov (United States)

    Abdel-Latif, I. A.; Al-Hajry, A.; Hashem, H.; Ghoza, M. H.; El-Sherbini, Th.

    2011-10-01

    The present work deals with the particle size effect on the electrical properties in Neodymium Cobaltate-Manganites System. Neodymium Cobaltate materials could be used as hydrogen storage materials. Nd0.6Sr0.4MnxCo1-xO3; (x = 0, 0.3, 0.7 and 1 ) were prepared using co-precipitation method from the initial pure chlorides of neodymium, strontium cobalt and manganese to react with pure sodium hydroxide with the proper molar ratio. The synthesized composites were studied in details in terms of their morphological and structural properties. The energy dispersive spectroscopy EDS reveals that the synthesized composites are in proper stoichiometry of the proposed structure. The obtained powder was pressed as disc at 2 T pressure are fired at different temperatures; 650°C, 750°C and 850°C. It was fired for 12h in each temperature. The X-ray analysis exhibited that crystal structure for all composites are the same and possessing single phase with orthorhombic crystal system of space group pnma (62). The DC resistivity as a function of temperature was measured in the range from room temperature up to 200° C.

  16. Physical Routes to Primitive Cells: An Experimental Model Based on the Spontaneous Entrapment of Enzymes inside Micrometer-Sized Liposomes.

    Science.gov (United States)

    D'Aguanno, Erica; Altamura, Emiliano; Mavelli, Fabio; Fahr, Alfred; Stano, Pasquale; Luisi, Pier Luigi

    2015-03-18

    How did primitive living cells originate? The formation of early cells, which were probably solute-filled vesicles capable of performing a rudimentary metabolism (and possibly self-reproduction), is still one of the big unsolved questions in origin of life. We have recently used lipid vesicles (liposomes) as primitive cell models, aiming at the study of the physical mechanisms for macromolecules encapsulation. We have reported that proteins and ribosomes can be encapsulated very efficiently, against statistical expectations, inside a small number of liposomes. Moreover the transcription-translation mixture, which realistically mimics a sort of minimal metabolic network, can be functionally reconstituted in liposomes owing to a self-concentration mechanism. Here we firstly summarize the recent advancements in this research line, highlighting how these results open a new vista on the phenomena that could have been important for the formation of functional primitive cells. Then, we present new evidences on the non-random entrapment of macromolecules (proteins, dextrans) in phospholipid vesicle, and in particular we show how enzymatic reactions can be accelerated because of the enhancement of their concentration inside liposomes.

  17. Physical Routes to Primitive Cells: An Experimental Model Based on the Spontaneous Entrapment of Enzymes inside Micrometer-Sized Liposomes

    Directory of Open Access Journals (Sweden)

    Erica D'Aguanno

    2015-03-01

    Full Text Available How did primitive living cells originate? The formation of early cells, which were probably solute-filled vesicles capable of performing a rudimentary metabolism (and possibly self-reproduction, is still one of the big unsolved questions in origin of life. We have recently used lipid vesicles (liposomes as primitive cell models, aiming at the study of the physical mechanisms for macromolecules encapsulation. We have reported that proteins and ribosomes can be encapsulated very efficiently, against statistical expectations, inside a small number of liposomes. Moreover the transcription-translation mixture, which realistically mimics a sort of minimal metabolic network, can be functionally reconstituted in liposomes owing to a self-concentration mechanism. Here we firstly summarize the recent advancements in this research line, highlighting how these results open a new vista on the phenomena that could have been important for the formation of functional primitive cells. Then, we present new evidences on the non-random entrapment of macromolecules (proteins, dextrans in phospholipid vesicle, and in particular we show how enzymatic reactions can be accelerated because of the enhancement of their concentration inside liposomes.

  18. Application of porous titanium in prosthesis production using a moldless process: Evaluation of physical and mechanical properties with various particle sizes, shapes, and mixing ratios.

    Science.gov (United States)

    Prananingrum, Widyasri; Tomotake, Yoritoki; Naito, Yoshihito; Bae, Jiyoung; Sekine, Kazumitsu; Hamada, Kenichi; Ichikawa, Tetsuo

    2016-08-01

    The prosthetic applications of titanium have been challenging because titanium does not possess suitable properties for the conventional casting method using the lost wax technique. We have developed a production method for biomedical application of porous titanium using a moldless process. This study aimed to evaluate the physical and mechanical properties of porous titanium using various particle sizes, shapes, and mixing ratio of titanium powder to wax binder for use in prosthesis production. CP Ti powders with different particle sizes, shapes, and mixing ratios were divided into five groups. A 90:10wt% mixture of titanium powder and wax binder was prepared manually at 70°C. After debinding at 380°C, the specimen was sintered in Ar at 1100°C without a mold for 1h. The linear shrinkage ratio of sintered specimens ranged from 2.5% to 14.2%. The linear shrinkage ratio increased with decreasing particle size. While the linear shrinkage ratio of Groups 3, 4, and 5 were approximately 2%, Group 1 showed the highest shrinkage of all. The bending strength ranged from 106 to 428MPa under the influence of porosity. Groups 1 and 2 presented low porosity followed by higher strength. The shear bond strength ranged from 32 to 100MPa. The shear bond strength was also particle-size dependent. The decrease in the porosity increased the linear shrinkage ratio and bending strength. Shrinkage and mechanical strength required for prostheses were dependent on the particle size and shape of titanium powders. These findings suggested that this production method can be applied to the prosthetic framework by selecting the material design.

  19. Application of porous titanium in prosthesis production using a moldless process: Evaluation of physical and mechanical properties with various particle sizes, shapes, and mixing ratios.

    Science.gov (United States)

    Prananingrum, Widyasri; Tomotake, Yoritoki; Naito, Yoshihito; Bae, Jiyoung; Sekine, Kazumitsu; Hamada, Kenichi; Ichikawa, Tetsuo

    2016-08-01

    The prosthetic applications of titanium have been challenging because titanium does not possess suitable properties for the conventional casting method using the lost wax technique. We have developed a production method for biomedical application of porous titanium using a moldless process. This study aimed to evaluate the physical and mechanical properties of porous titanium using various particle sizes, shapes, and mixing ratio of titanium powder to wax binder for use in prosthesis production. CP Ti powders with different particle sizes, shapes, and mixing ratios were divided into five groups. A 90:10wt% mixture of titanium powder and wax binder was prepared manually at 70°C. After debinding at 380°C, the specimen was sintered in Ar at 1100°C without a mold for 1h. The linear shrinkage ratio of sintered specimens ranged from 2.5% to 14.2%. The linear shrinkage ratio increased with decreasing particle size. While the linear shrinkage ratio of Groups 3, 4, and 5 were approximately 2%, Group 1 showed the highest shrinkage of all. The bending strength ranged from 106 to 428MPa under the influence of porosity. Groups 1 and 2 presented low porosity followed by higher strength. The shear bond strength ranged from 32 to 100MPa. The shear bond strength was also particle-size dependent. The decrease in the porosity increased the linear shrinkage ratio and bending strength. Shrinkage and mechanical strength required for prostheses were dependent on the particle size and shape of titanium powders. These findings suggested that this production method can be applied to the prosthetic framework by selecting the material design. PMID:27148637

  20. Short term secular change in body size and physical fitness of youth 7–15 years in Southwestern Poland: 2001–2002 and 2010–2011

    Directory of Open Access Journals (Sweden)

    Ignasiak Zofia

    2016-09-01

    Full Text Available Short term secular change in body size and physical fitness of Polish youth 7-15 years of age resident in an industrial region of Lower Silesia in southwestern Poland was considered across two surveys, 2001-2002 and 2010-2011. Subjects were students in the same schools in both surveys 1892 boys and 1992 girls in the first and 1237 boys and 1236 girls in the second. In addition to height and weight, performances in six fitness tests were measured in each survey. Height, weight and BMI increased significantly across surveys. Statistically controlling for secular gains in height and weight, only static strength (hand grip and running speed - agility (shuttle run improved significantly between surveys in three age groups (7-9, 10-12, 13-15 years, while explosive power (standing long jump showed negligible changes except in girls 13-15 years among whom performances declined significantly. Speed of upper limb movement (plate tapping, flexibility (sit and reach and trunk strength (sit-ups declined between surveys, except for trunk strength in boys 13-15 years which did not change. In conclusion, after statistically controlling for secular gains in body size, physical fitness items changed variably over the decade.

  1. Room temperature synthesis of highly hemocompatible hydroxyapatite, study of their physical properties and spectroscopic correlation of particle size

    Science.gov (United States)

    Puvvada, Nagaprasad; Panigrahi, Pravas Kumar; Pathak, Amita

    2010-12-01

    Needle shaped nanoparticles of hydroxyapatite (HA) have been synthesized at room temperature using orthophosphoric acid as the source of (PO4)3- ions, while calcium chloride, the calcium source, is suitably complexed with citric acid/tartaric acid/acetic acid. The presence of ligands inhibits the growth along [001] and [100] directions of the crystal and thus, helps in formation of needle shaped nanoparticles. The chemical compositions of the samples have been established through AAS and FTIR spectroscopy, while the crystallinity has been assessed through XRD and by the spectral changes in the υ1 and υ3 frequencies of the phosphate group in the respective FTIR spectra. The particle sizes of the samples have been determined from line broadening studies and correlations have been established between the curve fitted percentage area of FTIR and full width half height (FWHH) of the XRD peaks. TEM studies revealed the particle to be needle-shaped with a length and diameter in the range of 20-65 nm and 4-11 nm respectively. Changes in the surface charge of the water dispersed HA samples have been determined at different pH and the isoelectric point for the samples have been found in the range of 3.1-3.4. Finally, the morphology, surface area and hemocompatibility characteristics of the HA samples, prepared by using different complexing agents, have been compared.Needle shaped nanoparticles of hydroxyapatite (HA) have been synthesized at room temperature using orthophosphoric acid as the source of (PO4)3- ions, while calcium chloride, the calcium source, is suitably complexed with citric acid/tartaric acid/acetic acid. The presence of ligands inhibits the growth along [001] and [100] directions of the crystal and thus, helps in formation of needle shaped nanoparticles. The chemical compositions of the samples have been established through AAS and FTIR spectroscopy, while the crystallinity has been assessed through XRD and by the spectral changes in the υ1 and υ3

  2. Comparison of fluvial suspended-sediment concentrations and particle-size distributions measured with in-stream laser diffraction and in physical samples

    Science.gov (United States)

    Czuba, Jonathan A.; Straub, Timothy D.; Curran, Christopher A.; Landers, Mark N.; Domanski, Marian M.

    2014-01-01

    Laser-diffraction technology, recently adapted for in-stream measurement of fluvial suspended-sediment concentrations (SSCs) and particle-size distributions (PSDs), was tested with a streamlined (SL), isokinetic version of the Laser In-Situ Scattering and Transmissometry (LISST) for measuring volumetric SSCs and PSDs ranging from 1.8-415 µm in 32 log-spaced size classes. Measured SSCs and PSDs from the LISST-SL were compared to a suite of 22 datasets (262 samples in all) of concurrent suspended-sediment and streamflow measurements using a physical sampler and acoustic Doppler current profiler collected during 2010-12 at 16 U.S. Geological Survey streamflow-gaging stations in Illinois and Washington (basin areas: 38 – 69,264 km2). An unrealistically low computed effective density (mass SSC / volumetric SSC) of 1.24 g/ml (95% confidence interval: 1.05-1.45 g/ml) provided the best-fit value (R2 = 0.95; RMSE = 143 mg/L) for converting volumetric SSC to mass SSC for over 2 orders of magnitude of SSC (12-2,170 mg/L; covering a substantial range of SSC that can be measured by the LISST-SL) despite being substantially lower than the sediment particle density of 2.67 g/ml (range: 2.56-2.87 g/ml, 23 samples). The PSDs measured by the LISST-SL were in good agreement with those derived from physical samples over the LISST-SL's measureable size range. Technical and operational limitations of the LISST-SL are provided to facilitate the collection of more accurate data in the future. Additionally, the spatial and temporal variability of SSC and PSD measured by the LISST-SL is briefly described to motivate its potential for advancing our understanding of suspended-sediment transport by rivers.

  3. Neighbourhoods for Active Kids: study protocol for a cross-sectional examination of neighbourhood features and children's physical activity, active travel, independent mobility and body size

    Science.gov (United States)

    Oliver, Melody; McPhee, Julia; Carroll, Penelope; Ikeda, Erika; Mavoa, Suzanne; Mackay, Lisa; Kearns, Robin A; Kyttä, Marketta; Asiasiga, Lanuola; Garrett, Nicholas; Lin, Judy; Mackett, Roger; Zinn, Caryn; Moewaka Barnes, Helen; Egli, Victoria; Prendergast, Kate; Witten, Karen

    2016-01-01

    Introduction New Zealand children's physical activity, including independent mobility and active travel, has declined markedly over recent decades. The Neighbourhoods for Active Kids (NfAK) study examines how neighbourhood built environments are associated with the independent mobility, active travel, physical activity and neighbourhood experiences of children aged 9–12 years in primary and intermediate schools across Auckland, New Zealand's largest city. Methods and analysis Child-specific indices of walkability, destination accessibility and traffic exposure will be constructed to measure the built environment in 8 neighbourhoods in Auckland. Interactive online-mapping software will be used to measure children's independent mobility and transport mode to destinations and to derive measures of neighbourhood use and perceptions. Physical activity will be measured using 7-day accelerometry. Height, weight and waist circumference will be objectively measured. Parent telephone interviews will collect sociodemographic information and parent neighbourhood perceptions. Interviews with school representative will capture supports and barriers for healthy activity and nutrition behaviours at the school level. Multilevel modelling approaches will be used to understand how differing built environment variables are associated with activity, neighbourhood experiences and health outcomes. Discussion We anticipate that children who reside in neighbourhoods considered highly walkable will be more physically active, accumulate more independent mobility and active travel, and be more likely to have a healthy body size. This research is timely as cities throughout New Zealand develop and implement plans to improve the liveability of intensifying urban neighbourhoods. Results will be disseminated to participants, local government agencies and through conventional academic avenues. PMID:27531740

  4. Comparative physical-chemical characterization of encapsulated lipid-based isotretinoin products assessed by particle size distribution and thermal behavior analyses

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Carla Aiolfi, E-mail: carlaaiolfi@usp.br [Department of Pharmacy, Faculty of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, SP 05508-000 (Brazil); Menaa, Farid [Department of Dermatology, School of Medicine Wuerzburg, Wuerzburg 97080 (Germany); Fluorotronics, Inc., 1425 Russ Bvld, San Diego Technology Incubator, San Diego, CA 92101 (United States); Menaa, Bouzid, E-mail: bouzid.menaa@gmail.com [Fluorotronics, Inc., 1425 Russ Bvld, San Diego Technology Incubator, San Diego, CA 92101 (United States); Quenca-Guillen, Joyce S. [Department of Pharmacy, Faculty of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, SP 05508-000 (Brazil); Matos, Jivaldo do Rosario [Department of Fundamental Chemistry, Institute of Chemistry, University of Sao Paulo, Sao Paulo, SP 05508-000 (Brazil); Mercuri, Lucildes Pita [Department of Exact and Earth Sciences, Federal University of Sao Paulo, Diadema, SP 09972-270 (Brazil); Braz, Andre Borges [Department of Engineering of Mines and Oil, Polytechnical School, University of Sao Paulo, SP 05508-900 (Brazil); Rossetti, Fabia Cristina [Department of Pharmaceutical Sciences, Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP 14015-120 (Brazil); Kedor-Hackmann, Erika Rosa Maria; Santoro, Maria Ines Rocha Miritello [Department of Pharmacy, Faculty of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, SP 05508-000 (Brazil)

    2010-06-10

    Isotretinoin is the drug of choice for the management of severe recalcitrant nodular acne. Nevertheless, some of its physical-chemical properties are still poorly known. Hence, the aim of our study consisted to comparatively evaluate the particle size distribution (PSD) and characterize the thermal behavior of the three encapsulated isotretinoin products in oil suspension (one reference and two generics) commercialized in Brazil. Here, we show that the PSD, estimated by laser diffraction and by polarized light microscopy, differed between the generics and the reference product. However, the thermal behavior of the three products, determined by thermogravimetry (TGA), differential thermal (DTA) analyses and differential scanning calorimetry (DSC), displayed no significant changes and were more thermostable than the isotretinoin standard used as internal control. Thus, our study suggests that PSD analyses in isotretinoin lipid-based formulations should be routinely performed in order to improve their quality and bioavailability.

  5. Polymer Physics Prize Lecture: Self-assemblies of Giant Molecular Shape Amphiphiles as a New Platform for Engineering Structures with Sub-Nanometer Feature Sizes

    Science.gov (United States)

    Cheng, Stephen Z. D.

    2013-03-01

    Utilizing nano-building blocks rather than atoms to construct and engineer new structures is a fresh approach to design and develop functional materials for the purpose of transferring and amplifying microscopic functionality to macroscopic materials' property. As one of the important elements of these nano-building blocks, giant molecular shape amphiphiles (GMSAs) provide a latest platform for generating self-assembled ordered structures at nanometer scale, which are stabilized by collective physical bonds (such as collective hydrogen bonding). In this talk, two topics will be focused on. First, composed of functionalized hydrophilic molecular nanoparticles as the heads with rigid shape and fixed volume, and tethered polymer chains as the tails (such as giant molecular surfactants and lipids and other topologies), these GMSAs of various architectures can self-assemble into highly diversified, thermodynamically stable microstructures at sub-10 nm length scale in the bulk, thin film and solution states. Second, GMSAs could also be constructed solely from nanoparticles interconnected via different numbers of the rigid linkages in specific symmetry, simulating the overall shapes of small molecules but with sizes that are one-order of magnitude larger in length and three-order of magnitude larger in volume. Giant crystal structures can then be obtained from this class of ``giant molecules'' via supramolecular crystallization. These findings are not only scientifically intriguing in understanding the physical principles underlying their self-assembly, but also technologically relevant in industrial applications.

  6. The minimum or natural rate of flow and droplet size ejected by Taylor cone–jets: physical symmetries and scaling laws

    International Nuclear Information System (INIS)

    We aim to establish the scaling laws for both the minimum rate of flow attainable in the steady cone–jet mode of electrospray, and the size of the resulting droplets in that limit. Use is made of a small body of literature on Taylor cone–jets reporting precise measurements of the transported electric current and droplet size as a function of the liquid properties and flow rate. The projection of the data onto an appropriate non-dimensional parameter space maps a region bounded by the minimum rate of flow attainable in the steady state. To explain these experimental results, we propose a theoretical model based on the generalized concept of physical symmetry, stemming from the system time invariance (steadiness). A group of symmetries rising at the cone-to-jet geometrical transition determines the scaling for the minimum flow rate and related variables. If the flow rate is decreased below that minimum value, those symmetries break down, which leads to dripping. We find that the system exhibits two instability mechanisms depending on the nature of the forces arising against the flow: one dominated by viscosity and the other by the liquid polarity. In the former case, full charge relaxation is guaranteed down to the minimum flow rate, while in the latter the instability condition becomes equivalent to the symmetry breakdown by charge relaxation or separation. When cone–jets are formed without artificially imposing a flow rate, a microjet is issued quasi-steadily. The flow rate naturally ejected this way coincides with the minimum flow rate studied here. This natural flow rate determines the minimum droplet size that can be steadily produced by any electrohydrodynamic means for a given set of liquid properties. (paper)

  7. Utilization of Benchtop Next Generation Sequencing Platforms Ion Torrent PGM and MiSeq in Noninvasive Prenatal Testing for Chromosome 21 Trisomy and Testing of Impact of In Silico and Physical Size Selection on Its Analytical Performance.

    Directory of Open Access Journals (Sweden)

    Gabriel Minarik

    Full Text Available The aims of this study were to test the utility of benchtop NGS platforms for NIPT for trisomy 21 using previously published z score calculation methods and to optimize the sample preparation and data analysis with use of in silico and physical size selection methods.Samples from 130 pregnant women were analyzed by whole genome sequencing on benchtop NGS systems Ion Torrent PGM and MiSeq. The targeted yield of 3 million raw reads on each platform was used for z score calculation. The impact of in silico and physical size selection on analytical performance of the test was studied.Using a z score value of 3 as the cut-off, 98.11%-100% (104-106/106 specificity and 100% (24/24 sensitivity and 99.06%-100% (105-106/106 specificity and 100% (24/24 sensitivity were observed for Ion Torrent PGM and MiSeq, respectively. After in silico based size selection both platforms reached 100% specificity and sensitivity. Following the physical size selection z scores of tested trisomic samples increased significantly--p = 0.0141 and p = 0.025 for Ion Torrent PGM and MiSeq, respectively.Noninvasive prenatal testing for chromosome 21 trisomy with the utilization of benchtop NGS systems led to results equivalent to previously published studies performed on high-to-ultrahigh throughput NGS systems. The in silico size selection led to higher specificity of the test. Physical size selection performed on isolated DNA led to significant increase in z scores. The observed results could represent a basis for increasing of cost effectiveness of the test and thus help with its penetration worldwide.

  8. Analysis and Visualization of 2D and 3D Grain and Pore Size ofFontainebleau Sandstone Using Digital Rock Physics

    Science.gov (United States)

    Latief, FDE

    2016-08-01

    Fontainebleau sandstone is sandstone found in one of the cities in France. This sandstone has unique characteristics, which is a clean-fme sandstone, composed of 99% quartz, virtually devoid of clay, with the grain size of about 200 μm. Fontainebleau sandstone is widely used as a reference in the study of rock microstructure analysis and modelling. In this work analysis regarding the grain and pore size of Fontainebleau is presented. Calculation of 2D pore size and grain size distribution were done on the 299 slice of digital image of the Fontainebleau sandstone using Feret's diameters, equivalent diameters (d = 4A/P), and by means of local thickness/separation using plate model. For the 3D grain and pore size distribution, calculation of local thickness and local separation of the structure were used. Two dimensional analysis by means of Feret's diameter and equivalent diameter reveal that both grain and pore size distributions are in the form of reverse-J shaped (right skewed) while the local thickness/separation approach produces almost similar to symmetric Gaussian distribution. Three dimensional analysis produces fairly symmetric Gaussian distribution for both the grain and pore size. Further image processing were conducted and were succeed in producing three dimensional visual of the colour coded structure thickness (grain related) and structure separation (pore related).

  9. On-line coupling of surface plasmon resonance optical sensing to size-exclusion chromatography for affinity assessment of antibody samples.

    Science.gov (United States)

    Lakayan, Dina; Haselberg, Rob; Niessen, Wilfried M A; Somsen, Govert W; Kool, Jeroen

    2016-06-24

    Surface plasmon resonance (SPR) is an optical technique that measures biomolecular interactions. Stand-alone SPR cannot distinguish different binding components present in one sample. Moreover, sample matrix components may show non-specific binding to the sensor surface, leading to detection interferences. This study describes the development of coupled size-exclusion chromatography (SEC) SPR sensing for the separation of sample components prior to their on-line bio-interaction analysis. A heterogeneous polyclonal human serum albumin antibody (anti-HSA) sample, which was characterized by proteomics analysis, was used as test sample. The proposed SEC-SPR coupling was optimized by studying system parameters, such as injection volume, flow rate and sample concentration, using immobilized HSA on the sensor chip. Automated switch valves were used for on-line regeneration of the SPR sensor chip in between injections and for potential chromatographic heart cutting experiments, allowing SPR detection of individual components. The performance of the SEC-SPR system was evaluated by the analysis of papain-digested anti-HSA sampled at different incubation time points. The new on-line SEC-SPR methodology allows specific label-free analysis of real-time interactions of eluting antibody sample constituents towards their antigenic target. PMID:27215465

  10. Effects of physical form and stage of maturity at harvest of whole-crop barley silage on intake, chewing activity, diet selection and faecal particle size of dairy steers

    DEFF Research Database (Denmark)

    Rustas, B.-O.; Nørgaard, Peder; Jalali, Alireza;

    2010-01-01

    This study examined the effects of physical form and stage of maturity at harvest of whole-crop barley silage (WCBS) on feed intake, eating and rumination activity, diet selection and faecal particle size in dairy steers. Whole-crop barley was harvested and ensiled in round bales. Eight dairy...... starch in the WCBS (P ... starch digestibility. In conclusion, chopping increased DM intake of WCBS when harvested at dough...

  11. Project Energize: whole-region primary school nutrition and physical activity programme; evaluation of body size and fitness 5 years after the randomised controlled trial.

    Science.gov (United States)

    Rush, Elaine; McLennan, Stephanie; Obolonkin, Victor; Vandal, Alain C; Hamlin, Michael; Simmons, David; Graham, David

    2014-01-28

    Project Energize, a region-wide whole-school nutrition and physical activity programme, commenced as a randomised controlled trial (RCT) in the period 2004-6 in 124 schools in Waikato, New Zealand. In 2007, sixty-two control schools were engaged in the programme, and by 2011, all but two of the 235 schools in the region were engaged. Energizers (trained nutrition and physical activity specialists) work with eight to twelve schools each to achieve the goals of the programme, which are based on healthier eating and enhanced physical activity. In 2011, indices of obesity and physical fitness of 2474 younger (7·58 (sd 0·57) years) and 2330 older (10·30 (sd 0·51) years) children attending 193 of the 235 primary schools were compared with historical measurements. After adjusting for age, sex, ethnicity, socio-economic status (SES) and school cluster effects, the combined prevalence of obesity and overweight among younger and older children in 2011 was lower by 31 and 15 %, respectively, than that among 'unEnergized' children in the 2004 to 2006 RCT. Similarly, BMI was lower by 3·0 % (95 % CI - 5·8, - 1·3) and 2·4 % (95 % CI - 4·3, - 0·5). Physical fitness (time taken to complete a 550 m run) was significantly higher in the Energized children (13·7 and 11·3 %, respectively) than in a group of similarly aged children from another region. These effects were observed for boys and girls, both indigenous Māori and non-Māori children, and across SES. The long-term regional commitment to the Energize programme in schools may potentially lead to a secular reduction in the prevalence of overweight and obesity and gains in physical fitness, which may reduce the risk of developing obesity and type 2 diabetes. PMID:23867069

  12. Application of Physically-Based Slope Correction for Maximum Forest Canopy Height Estimation Using Waveform Lidar across Different Footprint Sizes and Locations: Tests on LVIS and GLAS

    Directory of Open Access Journals (Sweden)

    Taejin Park

    2014-07-01

    Full Text Available Forest canopy height is an important biophysical variable for quantifying carbon storage in terrestrial ecosystems. Active light detection and ranging (lidar sensors with discrete-return or waveform lidar have produced reliable measures of forest canopy height. However, rigorous procedures are required for an accurate estimation, especially when using waveform lidar, since backscattered signals are likely distorted by topographic conditions within the footprint. Based on extracted waveform parameters, we explore how well a physical slope correction approach performs across different footprint sizes and study sites. The data are derived from airborne (Laser Vegetation Imaging Sensor; LVIS and spaceborne (Geoscience Laser Altimeter System; GLAS lidar campaigns. Comparisons against field measurements show that LVIS data can satisfactorily provide a proxy for maximum forest canopy heights (n = 705, RMSE = 4.99 m, and R2 = 0.78, and the simple slope correction grants slight accuracy advancement in the LVIS canopy height retrieval (RMSE of 0.39 m improved. In the same vein of the LVIS with relatively smaller footprint size (~20 m, substantial progress resulted from the physically-based correction for the GLAS (footprint size = ~50 m. When compared against reference LVIS data, RMSE and R2 for the GLAS metrics (n = 527 are improved from 12.74–7.83 m and from 0.54–0.63, respectively. RMSE of 5.32 m and R2 of 0.80 are finally achieved without 38 outliers (n = 489. From this study, we found that both LVIS and GLAS lidar campaigns could be benefited from the physical correction approach, and the magnitude of accuracy improvement was determined by footprint size and terrain slope.

  13. MO-E-17A-01: BEST IN PHYSICS (IMAGING) - Calculating SSDE From CT Exams Using Size Data Available in the DICOM Header of CT Localizer Radiographs

    International Nuclear Information System (INIS)

    Purpose: To demonstrate the feasibility of using existing data stored within the DICOM header of certain CT localizer radiographs as a patient size metric for calculating CT size-specific dose estimates (SSDE). Methods: For most Siemens CT scanners, the CT localizer radiograph (topogram) contains a private DICOM field that stores an array of numbers describing AP and LAT attenuation-based measures of patient dimension. The square root of the product of the AP and LAT size data, which provides an estimate of water-equivalent-diameter (WED), was calculated retrospectively from topogram data of 20 patients who received clinically-indicated abdomen/pelvis (n=10) and chest (n=10) scans (WED-topo). In addition, slice-by-slice water-equivalent-diameter (WED-image) and effective diameter (ED-image) values were calculated from the respective image data. Using TG-204 lookup tables, size-dependent conversion factors were determined based upon WED-topo, WED-image and ED-image values. These conversion factors were used with the reported CTDIvol to calculate slice-by-slice SSDE for each method. Averaging over all slices, a single SSDE value was determined for each patient and size metric. Patientspecific SSDE and CTDIvol values were then compared with patientspecific organ doses derived from detailed Monte Carlo simulations of fixed tube current scans. Results: For abdomen/pelvis scans, the average difference between liver dose and CTDIvol, SSDE(WED-topo), SSDE(WED-image), and SSDE(ED-image) was 18.70%, 8.17%, 6.84%, and 7.58%, respectively. For chest scans, the average difference between lung dose and CTDIvol, SSDE(WED-topo), SSDE(WED-image), and SSDE(ED-image) was 25.80%, 3.33%, 4.11%, and 7.66%, respectively. Conclusion: SSDE calculated using WED derived from data in the DICOM header of the topogram was comparable to SSDE calculated using WED and ED derived from axial images; each of these estimated organ dose to within 10% for both abdomen/pelvis and chest CT examinations

  14. On the influence of cell size in physically-based distributed hydrological modelling to assess extreme values in water resource planning

    Directory of Open Access Journals (Sweden)

    M. Egüen

    2012-05-01

    Full Text Available This paper studies the influence of changing spatial resolution on the implementation of distributed hydrological modelling for water resource planning in Mediterranean areas. Different cell sizes were used to investigate variations in the basin hydrologic response given by the model WiMMed, developed in Andalusia (Spain, in a selected watershed. The model was calibrated on a monthly basis from the available daily flow data at the reservoir that closes the watershed, for three different cell sizes, 30, 100, and 500 m, and the effects of this change on the hydrological response of the basin were analysed by means of the comparison of the hydrological variables at different time scales for a 3-yr-period, and the effective values for the calibration parameters obtained for each spatial resolution. The variation in the distribution of the input parameters due to using different spatial resolutions resulted in a change in the obtained hydrological networks and significant differences in other hydrological variables, both in mean basin-scale and values distributed in the cell level. Differences in the magnitude of annual and global runoff, together with other hydrological components of the water balance, became apparent. This study demonstrated the importance of choosing the appropriate spatial scale in the implementation of a distributed hydrological model to reach a balance between the quality of results and the computational cost; thus, 30 and 100-m could be chosen for water resource management, without significant decrease in the accuracy of the simulation, but the 500-m cell size resulted in significant overestimation of runoff and consequently, could involve uncertain decisions based on the expected availability of rainfall excess for storage in the reservoirs. Particular values of the effective calibration parameters are also provided for this hydrological model and the study area.

  15. Planosol soil sample size for computerized tomography measurement of physical parameters; Tamanho de amostras para a determinacao de parametros fisicos em Planossolo por tomografia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Pedrotti, Alceu [Sergipe Univ., Sao Cristovao, SE (Brazil). Dept. de Engenharia Agronomica]. E-mail: apedroti@ufs.br; Pauletto, Antonio [Universidade Federal de Pelotas, RS (Brazil). Faculdade de Agronomia Eliseu Maciel. Dept. de Solos; Crestana, Silvio; Cruvinel, Paulo Estevao; Vaz, Carlos Manoel Pedro; Naime, Joao de Mendonca; Silva, Alvaro Macedo da [Empresa Brasileira de Pesquisa Agropecuaria, Sao Carlos, SP (Brazil). Instrumentacao Agropecuaria

    2003-12-01

    Computerized tomography (CT) is an important tool in Soil Science for noninvasive measurement of density and water content of soil samples. This work aims to describe the aspects of sample size adequacy for Planosol (Albaqualf) and to evaluate procedures for statistical analysis, using a CT scanner with a {sup 241} Am source. Density errors attributed to the equipment are 0.051 and 0.046 Mg m{sup -3} for horizons A and B, respectively. The theoretical value for sample thickness for the Planosol, using this equipment, is 4.0 cm for the horizons A and B. The ideal thickness of samples is approximately 6.0 cm, being smaller for samples of the horizon B in relation to A. Alternatives for the improvement of the efficiency analysis and the reliability of the results obtained by CT are also discussed, and indicate good precision and adaptability of the application of this technology in Planosol (Albaqualf) studies. (author)

  16. Size matter!

    DEFF Research Database (Denmark)

    Hansen, Pelle Guldborg; Jespersen, Andreas Maaløe; Skov, Laurits Rhoden

    2015-01-01

    Objectives We examined how a reduction in plate size would affect the amount of food waste from leftovers in a field experiment at a standing lunch for 220 CEOs. Methods A standing lunch for 220 CEOs in the Danish Opera House was arranged to feature two identical buffets with plates of two...... different sizes. One buffet featured standard sized plates that served as control (standard size as provided by the caterer, 27cm). A second buffet featured smaller sized plates (24cm) that served as the intervention. After the lunch concluded (30 minutes), all leftover food was collected in designated...... trash bags according to size of plates and weighed in bulk. Results Those eating from smaller plates (n=145) left significantly less food to waste (aver. 14,8g) than participants eating from standard plates (n=75) (aver. 20g) amounting to a reduction of 25,8%. Conclusions Our field experiment tests...

  17. Influence of feed intake, forage physical form, and forage fiber content on particle size of masticated forage, ruminal digesta, and feces of dairy cows.

    Science.gov (United States)

    Shaver, R D; Nytes, A J; Satter, L D; Jorgensen, N A

    1988-06-01

    Two trials were conducted to determine particle size of masticates, ruminal digesta, and feces of dairy cows. In Trial 1, three Holstein cows with ruminal cannulae were fed prebloom alfalfa hay in long, chopped, or pelleted form in a Latin square design (21-d periods) conducted in early lactation (wk 3 to 11) and again during the dry period to attain high (3.75) and low (1.95% of BW) feed consumption. In trial 2, prebloom, midbloom, and full bloom alfalfa hay, mature bromegrass hay, and corn silage were fed to early lactation (wk 5 to 15) Holsteins in a 5 X 5 Latin square design (15-d periods). All diets (Trials 1 and 2) were formulated to 17% CP and contained forage:grain in a 60:40 ratio (DM basis). Similar particle distributions of digesta from long and chopped hay diets suggest little influence of chopping forage on particle size reduction when high quality forage is fed. The large proportion of DM in the small particle (less than .6 mm) pool in the rumen in both trials suggests that rate of escape of small particles from the rumen is an important factor influencing ruminal retention time. Increased proportion of coarse (greater than or equal to 2.36-mm screen) fecal particles at high intake and with fine grinding appears related to a reduction in chewing per unit feed consumed. Soluble DM and particulate matter passing a .063-mm screen made up a significant portion (30 to 50%) of the total DM sieved from all sampling sites in both trials. PMID:2841366

  18. A comparative study of the physical and chemical properties of nano-sized ZnO particles from multiple batches of three commercial products

    International Nuclear Information System (INIS)

    Given the broad commercial applications for ZnO nanomaterials, accurate attribution of physicochemical characteristics that induce toxic effects is particularly important. We report on the physicochemical properties of three commercial nano-ZnO products: Z-COTE and Z-COTE HP1 from BASF, and Nanosun from Micronisers, and, for reference, “bulk” ZnO from Sigma-Aldrich. Z-COTE, Nanosun and “bulk” consist of uncoated particles with different sizes, while Z-COTE HP1 consists of nanoparticles with a hydrophobic coating. Specific batches of these ZnO products were included in the OECD Sponsorship Programme to test manufactured nanomaterials. In order to identify properties potentially susceptible to variations between production runs, three additional batches of Z-COTE and Nanosun and two additional batches of Z-COTE HP1 were also investigated here. In general, all products showed little variation between batches for properties measured from powdered samples, but batch variations in the amount of surface coating were evident for the coated Z-COTE HP1. Properties measured with samples dispersed in liquids (agglomeration, photocatalytic activity, dissolution) were highly dependent on dispersion protocols, and this made it difficult to differentiate between differences due to dispersion and due to batches. However, batch-sensitive properties did appear to be present in Z-COTE and Z-COTE HP1 (photocatalytic activity), and Nanosun (dissolution). Intra-batch time and/or storage-dependent changes in the applied surface coating, noted specifically for the OECD batch of Z-COTE HP1, highlight the need for best practice when storing and accessing stocks of nano products. Awareness of inter-batch and intra-batch variability is essential for commercial applications and for nanotoxicological studies aimed at identifying links between physicochemical properties and any adverse effects in biological systems

  19. Physical and chemical properties of the regional mixed layer of Mexico's Megapolis – Part 2: Evaluation of measured and modeled trace gases and particle size distributions

    Directory of Open Access Journals (Sweden)

    C. Ochoa

    2012-04-01

    Full Text Available This study extends the work of Baumgardner et al. (2009 in which measurements of trace gases and particles, at a remote, high altitude mountain site, 60 km from Mexico City were analyzed with respect to the origin of the air masses. In the current evaluation, the temperature, water vapor, ozone (O3, carbon monoxide (CO, acyl peroxy nitrate (APN and particle size distributions (PSDs of the mass concentrations of sulfate, nitrate, ammonium and organic mass (OM were simulated with the WRF-Chem chemical transport model and compared with the measurements at the mountain site. The model predictions of the diurnal trends of the gases were well correlated with the measurements before the regional mixed layer (RML reached the measurement site but underestimated the concentration after that time. The differences are caused by an over rapid growth of the boundary layer by the model and too much dilution. There also is more O3 being actually produced by photochemical production downwind of the emission sources than predicted by the model.

    The measured and modeled PSDs compare very well with respect to their general shape and diameter of the peak concentrations. The spectra are lognormal with most of the mass in the accumulation mode and the geometric diameter centered at 200±20 nm, showing little observed or predicted change with respect to the time when the RML is above the Altzomoni research station. Only the total mass changed with time and air mass origin. The invariability of average diameter of the accumulation mode suggests that there is very little growth of the particles by condensation or coagulation past about six hours of aging downwind of the major sources of anthropogenic emissions in Mexico's Megapolis. This could greatly simplify parameterization in climate models although it is not known at this time if this invariance can be extended to other megacity regions.

  20. A comparative study of the physical and chemical properties of nano-sized ZnO particles from multiple batches of three commercial products

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Hong [Commonwealth Scientific and Industrial Research Organisation, Manufacturing Flagship (Australia); Coleman, Victoria A. [National Measurement Institute Australia, Nanometrology Section (Australia); Casey, Phil S., E-mail: Phil.Casey@csiro.au [Commonwealth Scientific and Industrial Research Organisation, Manufacturing Flagship (Australia); Angel, Brad [Commonwealth Scientific and Industrial Research Organisation, Land and Water Flagship (Australia); Catchpoole, Heather J. [National Measurement Institute Australia, Nanometrology Section (Australia); Waddington, Lynne [Commonwealth Scientific and Industrial Research Organisation, Manufacturing Flagship (Australia); McCall, Maxine J. [Commonwealth Scientific and Industrial Research Organisation, Food and Nutrition Flagship (Australia)

    2015-02-15

    Given the broad commercial applications for ZnO nanomaterials, accurate attribution of physicochemical characteristics that induce toxic effects is particularly important. We report on the physicochemical properties of three commercial nano-ZnO products: Z-COTE and Z-COTE HP1 from BASF, and Nanosun from Micronisers, and, for reference, “bulk” ZnO from Sigma-Aldrich. Z-COTE, Nanosun and “bulk” consist of uncoated particles with different sizes, while Z-COTE HP1 consists of nanoparticles with a hydrophobic coating. Specific batches of these ZnO products were included in the OECD Sponsorship Programme to test manufactured nanomaterials. In order to identify properties potentially susceptible to variations between production runs, three additional batches of Z-COTE and Nanosun and two additional batches of Z-COTE HP1 were also investigated here. In general, all products showed little variation between batches for properties measured from powdered samples, but batch variations in the amount of surface coating were evident for the coated Z-COTE HP1. Properties measured with samples dispersed in liquids (agglomeration, photocatalytic activity, dissolution) were highly dependent on dispersion protocols, and this made it difficult to differentiate between differences due to dispersion and due to batches. However, batch-sensitive properties did appear to be present in Z-COTE and Z-COTE HP1 (photocatalytic activity), and Nanosun (dissolution). Intra-batch time and/or storage-dependent changes in the applied surface coating, noted specifically for the OECD batch of Z-COTE HP1, highlight the need for best practice when storing and accessing stocks of nano products. Awareness of inter-batch and intra-batch variability is essential for commercial applications and for nanotoxicological studies aimed at identifying links between physicochemical properties and any adverse effects in biological systems.

  1. Size matter!

    DEFF Research Database (Denmark)

    Hansen, Pelle Guldborg; Jespersen, Andreas Maaløe; Skov, Laurits Rhoden

    2015-01-01

    Objectives We examined how a reduction in plate size would affect the amount of food waste from leftovers in a field experiment at a standing lunch for 220 CEOs. Methods A standing lunch for 220 CEOs in the Danish Opera House was arranged to feature two identical buffets with plates of two differ...

  2. Exploring Size.

    Science.gov (United States)

    Brand, Judith, Ed.

    1995-01-01

    "Exploring" is a magazine of science, art, and human perception that communicates ideas museum exhibits cannot demonstrate easily by using experiments and activities for the classroom. This issue concentrates on size, examining it from a variety of viewpoints. The focus allows students to investigate and discuss interconnections among apparently…

  3. 颗粒介质尺度效应的抗剪试验及物理机理分析%Shear test and physical mechanism analysis on size effect of granular media

    Institute of Scientific and Technical Information of China (English)

    房营光

    2014-01-01

    Shear test samples of different grain sizes are prepared by using mineral particles of soil, and a series of tests of quick direct shear and tri-axial shear are performed to study the size effect of granular media. Deformation curves and shear stress strength are given of test samples with particles of different size and volume fraction. On the basis of the ratio of micro-acting forces between particles to gravity and the cell element model, physical mechanism of grain size effect is, for the first time as far as we know, explained on the micro-level and mecro-level respectively. Test results show that the deformation characteristic of granular media is enhanced and its shear stress strength increases with increasing volume fraction and decreasing of particle size, and the effect of volume fraction on the deformation characteristics and strength is more notable than that of grain size. According to mechanism analysis on size effect, parameter ratio of micro-acting forces to gravity is suggested to assess aggregation and friction effects of particles in the media, and mecro-mechanism is interpreted as strain gradient and micro-cracks of deformation coordination leading to grain size effect. The cell element model presented in this paper can greatly reduce the degrees of freedom of granular media and provides an available way for calculation modeling in industry and engineering design.%针对颗粒介质力学特性的颗粒尺度效应研究,选用土矿物颗粒制备不同颗粒尺度的抗剪试样,进行一系列直剪快剪和三轴抗剪试验,测得了不同颗粒粒径和体分比试样的变形曲线及剪应力强度;基于颗粒间微观作用力与重力比值和胞元体模型,首次从微观和细观角度解释颗粒尺度效应的物理机理。结果表明,随着介质中粗颗粒的比例增加和粒径减小,介质变形特性增强,剪应力强度也随之提高;体分比对变形和强度特性的影响比粒径的影响更加

  4. Water absorption curve among two size physic nut (Jatropha curcas L. seeds. = Curva de absorção de água em sementes de Jatropha curcas L. com dois tamanhos.

    Directory of Open Access Journals (Sweden)

    Oscar José Smiderle

    2013-08-01

    Full Text Available Knowledge of water absorption patterns among seeds is important as it allows us to know the appropriate conditions for the rapid seedling emergence. The present study characterized water absorption curve among physic nut (Jatropha curcas L seeds. Seeds were classified as small and large according to the mass of a thousand seeds placed in gerbox, between sheets of germitest paper moistened with destilled water 2.5 times their weight and kept in a germination chamber maintained at 25°C. The experimental design was completely randomized in a 2 x 17 factorial scheme, namely 2 seed sizes (large and small and 17 imbibitions periods (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 16, 24, 32, 48, 72, 96, 120 and 144 hours with four replicates of 10 seeds per plot. Small seeds of physic nut weighed 715.4 g as a thousand seed mass while large seeds weighed 800 grams. Seeds of physic nutexhibit a triphasic pattern of water absorption. Small and large physic nut seeds exhibit the three physiological phases similarly,where phase II begins next to 32 hours of imbibition and extends up to 116 hours, when phase III starts. = O conhecimento do padrão de absorção de água em sementes é importante na medida em que sepermite avaliar as condições adequadas para a rápida emergência das plântulas. Objetivou-se com o presente trabalho caracterizar a curva de absorção de água em sementes de pinhão manso (Jatropha curcas L.. Sementes classificadas por meio da massa de mil sementes em pequenas e grandes foram dispostas entre folhas de papel germitest umedecido 2,5 vezes seu peso, com água destilada, no interior de gerbox, mantidos em câmara de germinação a 25ºC. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 2 x 17, sendo 2 tamanhos de sementes (grandes e pequenas, com 17 períodos de embebição (0; 0,5; 1; 2; 3; 4; 6; 8; 10; 16; 24; 32; 48; 72; 96; 120 e 144 horas e quatro repetições de 10 sementes por parcela. As sementes pequenas

  5. Numerosity perception after size adaptation

    Science.gov (United States)

    Zimmermann, Eckart; Fink, Gereon R.

    2016-01-01

    While some researchers propose the existence of a special numerosity sense, others challenge this view and argue that numerosity is derived from low-level features as density information. Here, we used size adaptation to manipulate the apparent area size of an object set without changing its physical density. After size adaptation, two probe patches were shown, each of which contained a specific numerosity of dots. Subjects were required to report, which probe patch contained more dots. Numerosity perception was compared between conditions where probe patches were adapted to appear smaller or larger. Size adaptation affected numerosity perception in a logarithmic fashion, increasing with the numerosity in the probe patch. No changes in density perception were found after size adaptation. Data suggest that size and density information play only a minor role in the estimation of low numerosities. In stark contrast, high numerosities strongly depend on size and density information. The data reinforce recent claims of separate mechanism for the perception of low and high numerosities. PMID:27650296

  6. Numerosity perception after size adaptation.

    Science.gov (United States)

    Zimmermann, Eckart; Fink, Gereon R

    2016-01-01

    While some researchers propose the existence of a special numerosity sense, others challenge this view and argue that numerosity is derived from low-level features as density information. Here, we used size adaptation to manipulate the apparent area size of an object set without changing its physical density. After size adaptation, two probe patches were shown, each of which contained a specific numerosity of dots. Subjects were required to report, which probe patch contained more dots. Numerosity perception was compared between conditions where probe patches were adapted to appear smaller or larger. Size adaptation affected numerosity perception in a logarithmic fashion, increasing with the numerosity in the probe patch. No changes in density perception were found after size adaptation. Data suggest that size and density information play only a minor role in the estimation of low numerosities. In stark contrast, high numerosities strongly depend on size and density information. The data reinforce recent claims of separate mechanism for the perception of low and high numerosities. PMID:27650296

  7. Physical Abuse

    Science.gov (United States)

    ... Additional Resources Return to: What is Elder Abuse? Physical Abuse Physical abuse is physical force or violence that results in ... may be acquaintances, sons, daughters, grandchildren, or others. Physical abuse that is perpetrated by spouses or intimate partners ...

  8. Nuclear physics

    Energy Technology Data Exchange (ETDEWEB)

    Kamal, Anwar

    2014-09-01

    Explains the concepts in detail and in depth. Provides step-by-step derivations. Contains numerous tables and diagrams. Supports learning and teaching with numerous worked examples, questions and problems with answers. Sketches also the historical development of the subject. This textbook explains the experimental basics, effects and theory of nuclear physics. It supports learning and teaching with numerous worked examples, questions and problems with answers. Numerous tables and diagrams help to better understand the explanations. A better feeling to the subject of the book is given with sketches about the historical development of nuclear physics. The main topics of this book include the phenomena associated with passage of charged particles and radiation through matter which are related to nuclear resonance fluorescence and the Moessbauer effect., Gamov's theory of alpha decay, Fermi theory of beta decay, electron capture and gamma decay. The discussion of general properties of nuclei covers nuclear sizes and nuclear force, nuclear spin, magnetic dipole moment and electric quadrupole moment. Nuclear instability against various modes of decay and Yukawa theory are explained. Nuclear models such as Fermi Gas Model, Shell Model, Liquid Drop Model, Collective Model and Optical Model are outlined to explain various experimental facts related to nuclear structure. Heavy ion reactions, including nuclear fusion, are explained. Nuclear fission and fusion power production is treated elaborately.

  9. Nuclear physics

    International Nuclear Information System (INIS)

    Explains the concepts in detail and in depth. Provides step-by-step derivations. Contains numerous tables and diagrams. Supports learning and teaching with numerous worked examples, questions and problems with answers. Sketches also the historical development of the subject. This textbook explains the experimental basics, effects and theory of nuclear physics. It supports learning and teaching with numerous worked examples, questions and problems with answers. Numerous tables and diagrams help to better understand the explanations. A better feeling to the subject of the book is given with sketches about the historical development of nuclear physics. The main topics of this book include the phenomena associated with passage of charged particles and radiation through matter which are related to nuclear resonance fluorescence and the Moessbauer effect., Gamov's theory of alpha decay, Fermi theory of beta decay, electron capture and gamma decay. The discussion of general properties of nuclei covers nuclear sizes and nuclear force, nuclear spin, magnetic dipole moment and electric quadrupole moment. Nuclear instability against various modes of decay and Yukawa theory are explained. Nuclear models such as Fermi Gas Model, Shell Model, Liquid Drop Model, Collective Model and Optical Model are outlined to explain various experimental facts related to nuclear structure. Heavy ion reactions, including nuclear fusion, are explained. Nuclear fission and fusion power production is treated elaborately.

  10. Size reduction machine

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, V.

    1999-12-15

    The Size Reduction Machine (SRM) is a mobile platform capable of shearing various shapes and types of metal components at a variety of elevations. This shearing activity can be performed without direct physical movement and placement of the shear head by the operator. The base unit is manually moved and roughly aligned to each cut location. The base contains the electronics: hydraulic pumps, servos, and actuators needed to move the shear-positioning arm. The movable arm allows the shear head to have six axes of movement and to cut to within 4 inches of a wall surface. The unit has a slick electrostatic capture coating to assist in external decontamination. Internal contamination of the unit is controlled by a high-efficiency particulate air (HEPA) filter on the cooling inlet fan. The unit is compact enough to access areas through a 36-inch standard door opening. This paper is an Innovative Technology Summary Report designed to provide potential users with the information they need to quickly determine if a technology would apply to a particular environmental management problem. They also are designed for readers who may recommend that a technology be considered by prospective users.

  11. Size reduction machine

    International Nuclear Information System (INIS)

    The Size Reduction Machine (SRM) is a mobile platform capable of shearing various shapes and types of metal components at a variety of elevations. This shearing activity can be performed without direct physical movement and placement of the shear head by the operator. The base unit is manually moved and roughly aligned to each cut location. The base contains the electronics: hydraulic pumps, servos, and actuators needed to move the shear-positioning arm. The movable arm allows the shear head to have six axes of movement and to cut to within 4 inches of a wall surface. The unit has a slick electrostatic capture coating to assist in external decontamination. Internal contamination of the unit is controlled by a high-efficiency particulate air (HEPA) filter on the cooling inlet fan. The unit is compact enough to access areas through a 36-inch standard door opening. This paper is an Innovative Technology Summary Report designed to provide potential users with the information they need to quickly determine if a technology would apply to a particular environmental management problem. They also are designed for readers who may recommend that a technology be considered by prospective users

  12. The NK1R-/- mouse phenotype suggests that small body size, with a sex- and diet-dependent excess in body mass and fat, are physical biomarkers for a human endophenotype with vulnerability to attention deficit hyperactivity disorder.

    Science.gov (United States)

    Pillidge, Katharine; Heal, David J; Stanford, S Clare

    2016-09-01

    The abnormal behaviour of NK1R-/- mice (locomotor hyperactivity, inattentiveness and impulsivity in the 5-Choice Serial Reaction-Time Test) is arguably analogous to that of patients with attention deficit hyperactivity disorder (ADHD). Evidence suggests that small body size and increased body weight are risk factors for ADHD. Here, we compared the body size, body mass and body composition of male and female NK1R-/- mice and their wildtypes that had been fed either standard laboratory chow or a high-fat (45%: 'Western') diet. Male NK1R-/- mice from both cohorts were approximately 7% shorter than wildtypes. A similar trend was evident in females. Male NK1R-/- mice fed the normal diet weighed less than wildtypes but the 'body mass index' ('mBMI': weight (mg)/length (cm)(2)) of female NK1R-/- mice was higher than wildtypes. When given the high-fat diet, the mBMI of both male and female NK1R-/- mice was higher than wildtypes. There were no consistent genotype or sex differences in protein, ash or water content of mice from the two cohorts. However, the fat content of male NK1R-/- mice on the Western diet was considerably (35%) higher than wildtypes and resembled that of females from both genotypes. We conclude that a lack of functional NK1R is associated with small body size but increases vulnerability to an increase in mBMI and fat content, especially in males. This phenotype could also be evident in ADHD patients with polymorphism(s) of the TACR1 gene (the human equivalent of Nk1r). PMID:27462087

  13. Does Class Size Matter?

    Science.gov (United States)

    Ehrenberg, Ronald G.; Brewer, Dominic J.; Gamoran, Adam; Willms, J. Douglas

    2001-01-01

    Reports on the significance of class size to student learning. Includes an overview of class size in various countries, the importance of teacher adaptability, and the Asian paradox of large classes allied to high test scores. (MM)

  14. Size and Political Participation

    DEFF Research Database (Denmark)

    Lassen, David Dreyer; Serritzlew, Søren

    This paper uses a novel research design to re-examine the causal effect of jurisdiction size on political participation. Two waves of municipal consolidation in Denmark, in 1970 and in 2005, provide exogenous variation in jurisdiction size.......This paper uses a novel research design to re-examine the causal effect of jurisdiction size on political participation. Two waves of municipal consolidation in Denmark, in 1970 and in 2005, provide exogenous variation in jurisdiction size....

  15. Physics Overview

    OpenAIRE

    Kuang, Yu-Ping

    1999-01-01

    Recent developments of physics at the TeV energy scale, especially physics related to the electron-positron linear colliders are briefly reviewed. The topics include the present status of the standard model, Higgs physics, supersymmetry, strongly interacting electroweak symmetry breaking mechanism, and top quark physics.

  16. Interocular induction of illusory size perception

    Directory of Open Access Journals (Sweden)

    Schwarzkopf D Samuel

    2011-03-01

    Full Text Available Abstract Background The perceived size of objects not only depends on their physical size but also on the surroundings in which they appear. For example, an object surrounded by small items looks larger than a physically identical object surrounded by big items (Ebbinghaus illusion, and a physically identical but distant object looks larger than an object that appears closer in space (Ponzo illusion. Activity in human primary visual cortex (V1 reflects the perceived rather than the physical size of objects, indicating an involvement of V1 in illusory size perception. Here we investigate the role of eye-specific signals in two common size illusions in order to provide further information about the mechanisms underlying illusory size perception. Results We devised stimuli so that an object and its spatial context associated with illusory size perception could be presented together to one eye or separately to two eyes. We found that the Ponzo illusion had an equivalent magnitude whether the objects and contexts were presented to the same or different eyes, indicating that it may be largely mediated by binocular neurons. In contrast, the Ebbinghaus illusion became much weaker when objects and their contexts were presented to different eyes, indicating important contributions to the illusion from monocular neurons early in the visual pathway. Conclusions Our findings show that two well-known size illusions - the Ponzo illusion and the Ebbinghaus illusion - are mediated by different neuronal populations, and suggest that the underlying neural mechanisms associated with illusory size perception differ and can be dependent on monocular channels in the early visual pathway.

  17. Physical ergonomics

    OpenAIRE

    Looze, M. de; Koningsveld, E.

    2013-01-01

    Physical ergonomics deals with the physical load on the human body when performing activities like work, sports, jobs at home or dealing with products. With regard to the exposure to physical loads and its potential effects on the human body, the presented framework is helpful. In this article we explain more about the backgrounds of physical ergonomics, the risk assessment, the types of physical load: heavy work, repetitive work, and sedentary work.

  18. Physics Prospects at FAIR

    CERN Document Server

    Bleicher, M; Steinheimer, J; Bicudo, P

    2011-01-01

    We review the physics potential at FAIR in the light of the existing data of the RHIC-BES program and the NA49/NA61 beam and system size scan. Special emphasize will be put on the potential of fluctuations, as well as dilepton observables.

  19. Beyond Finite Size Scaling in Solidification Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Streitz, F H; Glosli, J N; Patel, M V

    2005-05-19

    Although computer simulation has played a central role in the study of nucleation and growth since the earliest molecular dynamics simulations almost 50 years ago, confusion surrounding the effect of finite size on such simulations have limited their applicability. Modeling solidification in molten tantalum on the BlueGene/L computer, we report here on the first atomistic simulation of solidification that verifies independence from finite size effects during the entire nucleation and growth process, up to the onset of coarsening. We show that finite size scaling theory explains the observed maximal grain sizes for systems up to about 8,000,000 atoms. For larger simulations, a cross-over from finite size scaling to more physical size-independent behavior is observed.

  20. Control of pore size in epoxy systems.

    Energy Technology Data Exchange (ETDEWEB)

    Sawyer, Patricia Sue; Lenhart, Joseph Ludlow (North Dakota State University, Fargo, ND); Lee, Elizabeth (North Dakota State University, Fargo, ND); Kallam, Alekhya (North Dakota State University, Fargo, ND); Majumdar, Partha (North Dakota State University, Fargo, ND); Dirk, Shawn M.; Gubbins, Nathan; Chisholm, Bret J. (North Dakota State University, Fargo, ND); Celina, Mathias Christopher; Bahr, James (North Dakota State University, Fargo, ND); Klein, Robert J.

    2009-01-01

    Both conventional and combinatorial approaches were used to study the pore formation process in epoxy based polymer systems. Sandia National Laboratories conducted the initial work and collaborated with North Dakota State University (NDSU) using a combinatorial research approach to produce a library of novel monomers and crosslinkers capable of forming porous polymers. The library was screened to determine the physical factors that control porosity, such as porogen loading, polymer-porogen interactions, and polymer crosslink density. We have identified the physical and chemical factors that control the average porosity, pore size, and pore size distribution within epoxy based systems.

  1. Statistical Physics

    CERN Document Server

    Mandl, Franz

    1988-01-01

    The Manchester Physics Series General Editors: D. J. Sandiford; F. Mandl; A. C. Phillips Department of Physics and Astronomy, University of Manchester Properties of Matter B. H. Flowers and E. Mendoza Optics Second Edition F. G. Smith and J. H. Thomson Statistical Physics Second Edition E. Mandl Electromagnetism Second Edition I. S. Grant and W. R. Phillips Statistics R. J. Barlow Solid State Physics Second Edition J. R. Hook and H. E. Hall Quantum Mechanics F. Mandl Particle Physics Second Edition B. R. Martin and G. Shaw The Physics of Stars Second Edition A. C. Phillips Computing for Scient

  2. Particle physics

    CERN Document Server

    Martin, Brian R

    2017-01-01

    An accessible and carefully structured introduction to Particle Physics, including important coverage of the Higgs Boson and recent progress in neutrino physics. Fourth edition of this successful title in the Manchester Physics series. Includes information on recent key discoveries including : An account of the discovery of exotic hadrons, beyond the simple quark model; Expanded treatments of neutrino physics and CP violation in B-decays; An updated account of ‘physics beyond the standard model’, including the interaction of particle physics with cosmology; Additional problems in all chapters, with solutions to selected problems available on the book’s website; Advanced material appears in optional starred sections.

  3. Planosol soil sample size for computerized tomography measurement of physical parameters Tamanho de amostras para a determinação de parâmetros físicos em planossolo por tomografia computadorizada

    Directory of Open Access Journals (Sweden)

    Alceu Pedrotti

    2003-12-01

    Full Text Available Computerized tomography (CT is an important tool in Soil Science for noninvasive measurement of density and water content of soil samples. This work aims to describe the aspects of sample size adequacy for Planosol (Albaqualf and to evaluate procedures for statistical analysis, using a CT scanner with a 241Am source. Density errors attributed to the equipment are 0.051 and 0.046 Mg m-3 for horizons A and B, respectively. The theoretical value for sample thickness for the Planosol, using this equipment, is 4.0 cm for the horizons A and B. The ideal thickness of samples is approximately 6.0 cm, being smaller for samples of the horizon B in relation to A. Alternatives for the improvement of the efficiency analysis and the reliability of the results obtained by CT are also discussed, and indicate good precision and adaptability of the application of this technology in Planosol (Albaqualf studies.A técnica da tomografia computadorizada (TC permite medir a densidade e a umidade de amostras de solo, constituindo uma importante ferramenta na Ciência do Solo. Este trabalho tem como objetivos descrever os aspectos da adequação do tamanho de amostras de um Planossolo e os procedimentos de avaliação e estudos por análise estatística, empregando-se um minitomógrafo computadorizado de raios gama com fonte de 241Am. O valor do erro atribuído ao equipamento são 0,051 e 0,046 Mg m-3, respectivamente, para os horizontes A e B. O valor teórico da espessura da amostra do Planossolo para uso na técnica de TC com fonte de 241Am é, aproximadamente, 4,0 cm para os horizontes A e B. Já a espessura ideal de amostras é de aproximadamente 6,0 cm, sendo menor para amostras do horizonte B em relação ao A. Obteve-se boa precisão e adaptabilidade no emprego da TC para estudos de Planossolos.

  4. PENGARUH UKURAN PARTIKEL DAN PROPORSI GULURONAT/MANURONAT DALAM ALGINAT TERHADAP SIFAT DAN SENSORIS PRODUK HASIL RESTRUKTURISASI DARI BUAH SIRSAK [The Influence of Particle size and Guluronic/Mannuronic Proportion of Alginate on Physical and Sensory Characteristics of Restructured Products from Soursop

    Directory of Open Access Journals (Sweden)

    Sri Raharjo

    2003-12-01

    Full Text Available The application of restructuring technology is intended to add value for local fruits. Fresh and ripe sour sop fruits are frequently of having defective appearance, irregular shape and size, or showing signs of insect infestation which make the whole fruit is less acceptable by consumers. Previous study has indicated that sour sop fruit can be restructured into a fresh fruit product with acceptable sensory characteristics using calcium alginate gel system. This particular study was intended to determine the effect of alginate powder particles size and its guluronic/mannuronic proportion on the physical and sensorial properties of restructured sour sop. The restructured fruit product was evaluated based on its gel strength, pH colour, and sensory attributes which include taste, aroma, mouth feel, appearance, and hardness. Sour sop restructured by internal setting with coarse alginate powder (36 mesh tend to have softer gel compared to the use of fine alginate powder (120 mesh. Different proportion of guluronic/mannuronic in the alginate used for the restructurization resulted in the same gel strength when calcium lactate powder was used. However, the use of encapsulated calcium lactate resulted in stronger gel with alginate containing higher proportion of mannuronic acid. The alginate particle size and proportion of guluronic/mannuronic content showed no significant difference in product colour and sensory attributes evaluated.

  5. The Surface-to-Volume Ratio in Thermal Physics: From Cheese Cube Physics to Animal Metabolism

    Science.gov (United States)

    Planinsic, Gorazd; Vollmer, Michael

    2008-01-01

    The surface-to-volume ratio is an important quantity in thermal physics. For example it governs the behaviour of heating or cooling of physical objects as a function of size like, e.g. cubes or spheres made of different material. The starting point in our paper is the simple physics problem of how cheese cubes of different sizes behave if heated…

  6. Efeito da redução do tamanho de lote e de programas de Melhoria Contínua no Estoque em Processo (WIP e na Utilização: estudo utilizando uma abordagem híbrida System Dynamics - Factory Physics Effect of lot size reduction and Continuous Improvement on Work In Process and Utilization: study using a combined System Dynamics and Factory Physics approach

    Directory of Open Access Journals (Sweden)

    Moacir Godinho Filho

    2009-04-01

    Full Text Available O presente trabalho apresenta um modelo quantitativo que utiliza de forma híbrida as abordagens System Dynamics - SD (FORRESTER, 1962 e Factory Physics (HOPP; SPEARMAN, 2001 objetivando estudar o efeito conjunto de seis programas de Melhoria Contínua - CI (variabilidade na taxa de chegada, variabilidade do processo, qualidade, tempo até a falha, tempo de reparo e tempo de set up e de redução de tamanhos de lote de produção nos níveis médios de Estoque em Processo (WIP e Utilização em um ambiente produtivo com uma única máquina que processa múltiplos produtos. Os resultados dos experimentos realizados utilizando-se o modelo desenvolvido fornecem insights e subsídios que dão suporte a uma série de modernas ferramentas e filosofias de gestão da manufatura, tais como programas de redução da variabilidade do processo como, por exemplo, Seis Sigma; programas de redução de set up, como por exemplo os programas SMED (Single Minute Exchange of Die, Sistema Toyota de Produção/Manufatura Enxuta e Quick Response Manufacturing (QRM. Além disso, o modelo também serve para auxiliar na escolha de diferentes possibilidades de programas de Melhoria Contínua no chão de fábrica.This paper builds a quantitative model, which is a result of a combination of System Dynamics (FORRESTER, 1962 and Factory Physics (HOPP; SPEARMAN, 2001 approaches aiming to examine how six Continuous Improvement (CI programs (arrival variability, process variability, quality (defect rate, time to failure, repair time, and set up time, together with lot size reduction, affect Work In Process (WIP and Utilization in a multi-product, single-machine environment. Results of the paper provides support for: i the importance of implementing set up reduction programs; ii Lean Manufacturing (LM philosophy regarding the implementation of small CI programs in a lot of variables and areas of the shop floor; iii Quick Response Manufacturing (QRM philosophy regarding the

  7. Physical activity

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/001941.htm Physical activity To use the sharing features on this page, please enable JavaScript. Physical activity -- which includes an active lifestyle and routine exercise -- ...

  8. Aristotle's physics

    CERN Document Server

    Rovelli, Carlo

    2013-01-01

    I show that Aristotelian physics is a correct approximation of Newtonian physics in its appropriate domain, in the same precise sense in which Newton theory is an approximation of Einstein's theory. Aristotelian physics lasted long not because it became dogma, but because it is a very good theory.

  9. Nanocoatings size effect in nanostructured films

    CERN Document Server

    Aliofkhazraei, Mahmood

    2014-01-01

    Size effect in structures has been taken into consideration over the last years. In comparison with coatings with micrometer-ranged thickness, nanostructured coatings usually enjoy better and appropriate properties, such as strength and resistance. These coatings enjoy unique magnetic properties and are used with the aim of producing surfaces resistant against erosion, lubricant system, cutting tools, manufacturing hardened sporadic alloys, being resistant against oxidation and corrosion. This book reviews researches on fabrication and classification of nanostructured coatings with focus on size effect in nanometric scale. Size effect on electrochemical, mechanical and physical properties of nanocoatings are presented.

  10. Fundamental science of nanometer-size clusters

    Energy Technology Data Exchange (ETDEWEB)

    Wilcoxon, J.P.; Newcomer, P.P.; Samara, G.A.; Venturini, E.L.; Williamson, R.L.

    1995-10-01

    This research has produced a variety of monodisperse, nanometer-size clusters (nanoclusters for short), characterized their size and crystal structure and developed a scientific understanding of the size dependence of their physical properties. Of specific interest were the influence of quantum electronic confinement on the optical properties, magnetic properties, and dielectric properties. These properties were chosen both for their potential practical impact on various applications identified in the National Critical Technologies list (e.g., catalysis, information storage, sensors, environmental remediation, ...) as well as for their importance to the fundamental science of clusters. An Executive Summary provides a description of the major highlights.

  11. Understanding physics

    CERN Document Server

    Mansfield, Michael

    2011-01-01

    Understanding Physics - Second edition is a comprehensive, yet compact, introductory physics textbook aimed at physics undergraduates and also at engineers and other scientists taking a general physics course. Written with today's students in mind, this text covers the core material required by an introductory course in a clear and refreshing way. A second colour is used throughout to enhance learning and understanding. Each topic is introduced from first principles so that the text is suitable for students without a prior background in physics. At the same time the book is designed to enable

  12. Physical Systems

    CERN Document Server

    Belkind, Ori

    2012-01-01

    Based on the concept of a physical system, this book offers a new philosophical interpretation of classical mechanics and the Special Theory of Relativity. According to Belkind's view the role of physical theory is to describe the motions of the parts of a physical system in relation to the motions of the whole. This approach provides a new perspective into the foundations of physical theory, where motions of parts and wholes of physical systems are taken to be fundamental, prior to spacetime, material properties and laws of motion. He defends this claim with a constructive project, deriving b

  13. Game physics

    CERN Document Server

    Eberly, David H

    2010-01-01

    ""Game Physics, 2nd Edition"" provides clear descriptions of the mathematics and algorithms needed to create a powerful physics engine - while providing a solid reference for all of the math you will encounter anywhere in game development: quaternions, linear algebra, and calculus. Implementing physical simulations for real-time games is a complex task that requires a solid understanding of a wide range of concepts from the fields of mathematics and physics. Previously, the relevant information could only be gleaned through obscure research papers. Thanks to ""Game Physics"", all this informa

  14. Particle Physics

    CERN Document Server

    Martin, B R

    2008-01-01

    An essential introduction to particle physics, with coverage ranging from the basics through to the very latest developments, in an accessible and carefully structured text. Particle Physics: Third Edition is a revision of a highly regarded introduction to particle physics. In its two previous editions this book has proved to be an accessible and balanced introduction to modern particle physics, suitable for those students needed a more comprehensive introduction to the subject than provided by the 'compendium' style physics books. In the Third Edition the standard mod

  15. Nozzles: selection and sizing

    OpenAIRE

    Grisso, Robert D. (Robert Dwight), 1956-; Hipkins, Patricia A.; Askew, Shawn; Hipkins, Perry Lloyd, 1945-; McCall, David Scott

    2013-01-01

    Covers nozzle description, recommended use for common nozzle types, and orifice sizing for agricultural and turf sprayers. Proper selection of a nozzle type and size is essential for correct and accurate pesticide application. The nozzle is a major factor in determining the amount of spray applied to an area, uniformity of application, coverage obtained on the target surface, and amount of potential drift.

  16. Efeitos do tamanho da partícula e da forma física da ração sobre o desempenho, rendimento de carcaça e peso dos órgãos digestivos de frangos de corte Effects of particle size and physical form of ration on performance, carcass yield and weight of digestive organs of broiler chickens

    Directory of Open Access Journals (Sweden)

    C.A.A. López

    2004-04-01

    Full Text Available Compararam-se os efeitos do tamanho da partícula e da forma física da ração sobre o desempenho, rendimento de carcaça e peso dos órgãos digestivos de frangos de corte. Foram utilizados 900 aves (machos da linhagem Ross-308, de 1 a 47 dias de idade. O delineamento experimental foi inteiramente ao acaso com arranjo fatorial 3×2 (três formas físicas - farelada, granulada e expandida-granulada - e dois tamanhos de partícula - média e grossa, com cinco repetições de 30 aves. Observou-se efeito de interação entre granulometria e forma física da ração para peso vivo (P granulada > farelada. Não foram observadas diferenças entre o peso dos frangos que receberam as rações com granulometria grossa e processadas. Os frangos alimentados com as rações fareladas e granulometria grossa foram significativamente mais leves em relação aos frangos dos outros tratamentos. O consumo de ração não foi influenciado pela granulometria. Observou-se efeito da interação granulometria e forma física da ração para conversão alimentar e viabilidade (PAn experiment was carried out to compare the effects of dietary particle size and physical form of the ration on performance and weights of digestive organs of broiler chickens. Nine hundred day-old broiler chicks male of Ross line were used during the 47 days of the trial. The experiment followed a completely randomized 3×2 factorial design: three physical forms of ration (mash, pellet and expanded-pellet x two methods of grinding (intermediary and coarse, with five replicates of 30 birds. Significant interaction effect of physical form of the ration and method of grinding on body weight was found (P pellet > mash. Dietary particle size did not affect feed intake of broilers. Birds fed processed rations had higher feed consumption. Significant interaction effect of the physical form of ration and grinding method on feed conversion and viability (P<0.05 was observed. Within intermediary

  17. Sample size methodology

    CERN Document Server

    Desu, M M

    2012-01-01

    One of the most important problems in designing an experiment or a survey is sample size determination and this book presents the currently available methodology. It includes both random sampling from standard probability distributions and from finite populations. Also discussed is sample size determination for estimating parameters in a Bayesian setting by considering the posterior distribution of the parameter and specifying the necessary requirements. The determination of the sample size is considered for ranking and selection problems as well as for the design of clinical trials. Appropria

  18. Ultrasonic physics

    CERN Document Server

    Richardson, E G

    1962-01-01

    Ultrasonic Physics, Second Edition, provides an introduction to the fundamental principles of ultrasonic physics. The book opens with a discussion of the sources of ultrasound. This is followed by separate chapters on the properties and detection of ultrasonic radiation; measurement of propagation constants, i.e., the velocity and absorption, of ultrasound; ultrasound propagation in gases, liquids, and solids; and ultrasound propagation in aerosols, suspensions, and emulsions. The final chapter covers miscellaneous physical and physico-chemical actions, including dispersion and coagulation of

  19. Molecular physics

    CERN Document Server

    Williams, Dudley

    2013-01-01

    Methods of Experimental Physics, Volume 3: Molecular Physics focuses on molecular theory, spectroscopy, resonance, molecular beams, and electric and thermodynamic properties. The manuscript first considers the origins of molecular theory, molecular physics, and molecular spectroscopy, as well as microwave spectroscopy, electronic spectra, and Raman effect. The text then ponders on diffraction methods of molecular structure determination and resonance studies. Topics include techniques of electron, neutron, and x-ray diffraction and nuclear magnetic, nuclear quadropole, and electron spin reson

  20. University physics

    CERN Document Server

    Arfken, George

    1984-01-01

    University Physics provides an authoritative treatment of physics. This book discusses the linear motion with constant acceleration; addition and subtraction of vectors; uniform circular motion and simple harmonic motion; and electrostatic energy of a charged capacitor. The behavior of materials in a non-uniform magnetic field; application of Kirchhoff's junction rule; Lorentz transformations; and Bernoulli's equation are also deliberated. This text likewise covers the speed of electromagnetic waves; origins of quantum physics; neutron activation analysis; and interference of light. This publi

  1. Neutrino physics

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Deborah A.; /Fermilab

    2008-09-01

    The field of neutrino physics has expanded greatly in recent years with the discovery that neutrinos change flavor and therefore have mass. Although there are many neutrino physics results since the last DIS workshop, these proceedings concentrate on recent neutrino physics results that either add to or depend on the understanding of Deep Inelastic Scattering. They also describe the short and longer term future of neutrino DIS experiments.

  2. The right size

    Energy Technology Data Exchange (ETDEWEB)

    Knowles, R. [Univ. of Southern California, Los Angeles, CA (United States)

    1996-10-01

    The right size, and notably the right size of a building, is relative. It is dependent upon the costs of construction and of maintenance. It is also proportional to the more illusory standards of livability and of choice. In order to make sense of this complex picture, a 10-year housing study has been undertaken in the USC School of Architecture comparing a range of sizes with reference to solar-access policy and design. Data have been systematically collected relating Density (a count of dwelling units per acre) to S/V (surface-to-volume ratio, and energy-related measure of building form). This relationship is taken as grounds for concluding that buildings of 3--7 stories generally represent the best size range for urban dwellings in Los Angeles. These figures can vary among cities; but the underlying suppositions of solar-access policy and design are broadly applicable to places of density everywhere.

  3. Particle Size Analysis.

    Science.gov (United States)

    Barth, Howard G.; Sun, Shao-Tang

    1989-01-01

    Presents a review of research focusing on scattering, elution techniques, electrozone sensing, filtration, centrifugation, comparison of techniques, data analysis, and particle size standards. The review covers the period 1986-1988. (MVL)

  4. Physical composition

    Science.gov (United States)

    Healey, Richard

    2013-02-01

    Atomistic metaphysics motivated an explanatory strategy which science has pursued with great success since the scientific revolution. By decomposing matter into its atomic and subatomic parts physics gave us powerful explanations and accurate predictions as well as providing a unifying framework for the rest of science. The success of the decompositional strategy has encouraged a widespread conviction that the physical world forms a compositional hierarchy that physics and other sciences are progressively articulating. But this conviction does not stand up to a closer examination of how physics has treated composition, as a variety of case studies will show.

  5. Action physics

    Science.gov (United States)

    McGinness, Lachlan P.; Savage, C. M.

    2016-09-01

    More than a decade ago, Edwin Taylor issued a "call to action" that presented the case for basing introductory university mechanics teaching around the principle of stationary action [E. F. Taylor, Am. J. Phys. 71, 423-425 (2003)]. We report on our response to that call in the form of an investigation of the teaching and learning of the stationary action formulation of physics in a first-year university course. Our action physics instruction proceeded from the many-paths approach to quantum physics to ray optics, classical mechanics, and relativity. Despite the challenges presented by action physics, students reported it to be accessible, interesting, motivational, and valuable.

  6. Computational physics

    CERN Document Server

    Newman, Mark

    2013-01-01

    A complete introduction to the field of computational physics, with examples and exercises in the Python programming language. Computers play a central role in virtually every major physics discovery today, from astrophysics and particle physics to biophysics and condensed matter. This book explains the fundamentals of computational physics and describes in simple terms the techniques that every physicist should know, such as finite difference methods, numerical quadrature, and the fast Fourier transform. The book offers a complete introduction to the topic at the undergraduate level, and is also suitable for the advanced student or researcher who wants to learn the foundational elements of this important field.

  7. Physical Activity

    DEFF Research Database (Denmark)

    Andersen, Lars Bo; Anderssen, Sigmund Alfred; Wisløff, Ulrik;

    2014-01-01

    Andersen LB, Anderssen SA, Wisløff U, Hellénius M-L, Fogelholm M, Ekelund U. (Expert Group) Nordic Nutrition Recommendations 2012. Integrating nutrition and physical activity. Chapter: Physical Activity p. 195-217.Nordic Counsil of Ministers.......Andersen LB, Anderssen SA, Wisløff U, Hellénius M-L, Fogelholm M, Ekelund U. (Expert Group) Nordic Nutrition Recommendations 2012. Integrating nutrition and physical activity. Chapter: Physical Activity p. 195-217.Nordic Counsil of Ministers....

  8. Compressors selection and sizing

    CERN Document Server

    Brown, Royce N

    2005-01-01

    This practical reference provides in-depth information required to understand and properly estimate compressor capabilities and to select the proper designs. Engineers and students will gain a thorough understanding of compression principles, equipment, applications, selection, sizing, installation, and maintenance. The many examples clearly illustrate key aspects to help readers understand the ""real world"" of compressor technology.Compressors: Selection and Sizing, third edition is completely updated with new API standards. Additions requested by readers include a new section on di

  9. Imagined Physics

    DEFF Research Database (Denmark)

    Merritt, Timothy Robert; Nørgaard, M.; Laursen, C.;

    2015-01-01

    to this book focuses on the human responses to objects that change shape in response to input from users, environment, or other circumstances. In this chapter we discuss the term "imagined physics", meaning how actuated devices are in one sense tied to their physical form, yet through the use of actuators...

  10. Climate Physics

    Science.gov (United States)

    Space, William

    2007-01-01

    Numerous connections exist between climate science and topics normally covered in physics and physical science courses. For instance, lessons on heat and light can be used to introduce basic climate science, and the study of electric circuits provides a context for studying the relationship between electricity consumption and carbon pollution. To…

  11. Understanding physics

    CERN Document Server

    Cassidy, David; Rutherford, James

    2002-01-01

    Understanding Physics provides a thorough grounding in contemporary physics while placing physics into its social and historical context Based in large part on the highly respected Project Physics Course developed by two of the authors, it also integrates the results of recent pedagogical research The text thus - teaches about the basic phenomena in the physical world and the concepts developed to explain them - shows that science is a rational human endeavor with a long and continuing tradition, involving many different cultures and people - develops facility in critical thinking, reasoned argumentation, evaluation of evidence, mathematical modeling, and ethical values The treatment emphasizes not only what we know but also how we know it, why we believe it, and what effects that knowledge has - Why do we believe the Earth and planets revolve around the Sun? - Why do we believe that matter is made of atoms? - How do relativity theory and quantum mechanics alter our conception of Nature and in what ways do th...

  12. Physical Education, Politics, and SPEAK Out! Day

    Science.gov (United States)

    Claxton, David; Kopp, Rachael; Skidmore, Lauren; Williams, Kimberly

    2013-01-01

    This article discusses the importance of politics in the lives of physical educators. Politics affects many decisions that are made about physical education programs (PEPs). In public schools, politics can affect the number of certified physical education teachers, available facilities, class sizes, and number of days per week that students go to…

  13. Plasma physics

    CERN Document Server

    Drummond, James E

    2013-01-01

    A historic snapshot of the field of plasma physics, this fifty-year-old volume offers an edited collection of papers by pioneering experts in the field. In addition to assisting students in their understanding of the foundations of classical plasma physics, it provides a source of historic context for modern physicists. Highly successful upon its initial publication, this book was the standard text on plasma physics throughout the 1960s and 70s.Hailed by Science magazine as a ""well executed venture,"" the three-part treatment ranges from basic plasma theory to magnetohydrodynamics and microwa

  14. Statistical physics

    CERN Document Server

    Wannier, Gregory H

    2010-01-01

    Until recently, the field of statistical physics was traditionally taught as three separate subjects: thermodynamics, statistical mechanics, and kinetic theory. This text, a forerunner in its field and now a classic, was the first to recognize the outdated reasons for their separation and to combine the essentials of the three subjects into one unified presentation of thermal physics. It has been widely adopted in graduate and advanced undergraduate courses, and is recommended throughout the field as an indispensable aid to the independent study and research of statistical physics.Designed for

  15. Interpreting Physics

    CERN Document Server

    MacKinnon, Edward

    2012-01-01

    This book is the first to offer a systematic account of the role of language in the development and interpretation of physics. An historical-conceptual analysis of the co-evolution of mathematical and physical concepts leads to the classical/quatum interface. Bohrian orthodoxy stresses the indispensability of classical concepts and the functional role of mathematics. This book analyses ways of extending, and then going beyond this orthodoxy orthodoxy. Finally, the book analyzes how a revised interpretation of physics impacts on basic philosophical issues: conceptual revolutions, realism, and r

  16. Atomic Physics

    CERN Document Server

    Foot, Christopher J

    2007-01-01

    This text will thoroughly update the existing literature on atomic physics. Intended to accompany an advanced undergraduate course in atomic physics, the book will lead the students up to the latest advances and the applications to Bose-Einstein Condensation of atoms, matter-wave inter-ferometry and quantum computing with trapped ions. The elementary atomic physics covered in the early chapters should be accessible to undergraduates when they are first introduced to the subject. To complement. the usual quantum mechanical treatment of atomic structure the book strongly emphasizes the experimen

  17. Complex systems: physics beyond physics

    CERN Document Server

    Holovatch, Yurij; Thurner, Stefan

    2016-01-01

    Complex systems are characterized by specific time-dependent interactions among their many constituents. As a consequence they often manifest rich, non-trivial and unexpected behavior. Examples arise both in the physical and non-physical world. The study of complex systems forms a new interdisciplinary research area that cuts across physics, biology, ecology, economics, sociology, and the humanities. In this paper we review the essence of complex systems from a physicist's point of view, and try to clarify what makes them conceptually different from systems that are traditionally studied in physics. Our goal is to demonstrate how the dynamics of such systems may be conceptualized in quantitative and predictive terms by extending notions from statistical physics and how they can often be captured in a framework of co-evolving multiplex network structures. We mention three areas of complex-systems science that are currently studied extensively, the science of cities, dynamics of societies, and the representatio...

  18. Engineering physics

    CERN Document Server

    Mukherji, Uma

    2015-01-01

    ENGINEERING PHYSICS is designed as a textbook for first year engineering students of a two semester course in Applied Physics according to new revised syllabus. However the scope of this book is not only limited to undergraduate engineering students and science students, it can also serve as a reference book for practicing scientists.Advanced technological topics like LCD, Squid, Maglev system, Electron microscopes, MRI, Photonics - Photonic fibre, Nano-particles, CNT, Quantum computing etc., are explained with basic underlying principles of Physics.This text explained following topics with numerous solved, unsolved problems and questions from different angles. Part-I contains crystal structure, Liquid crystal, Thermo-electric effect, Thermionic emission, Ultrasonic, Acoustics, semiconductor and magnetic materials. Whereas Part-2 contains Optics, X-rays, Electron optics, Dielectric materials, Quantum Physics and Schrodinger wave equation, Laser, Fibre-optics and Holography, Radio-activity, Super-conductivity,...

  19. Physical oceanography

    Digital Repository Service at National Institute of Oceanography (India)

    Murty, C.S.; Murty, V.S.N.

    The chapter on physical oceanography of the Indian Ocean is written keeping in mind the graduate students and researchers. It starts with a brief introduction (citing latest expeditions) followed by the coastal and near processes (wave climate...

  20. Magic Physics?

    Science.gov (United States)

    Featonby, David

    2010-01-01

    This article examines several readily available "magic tricks" which base their "trickery" on physics principles, and questions the use of the word "magic" in the 21st century, both in popular children's science and in everyday language. (Contains 18 figures.)

  1. Physical mathematics

    CERN Document Server

    Cahill, Kevin

    2013-01-01

    Unique in its clarity, examples and range, Physical Mathematics explains as simply as possible the mathematics that graduate students and professional physicists need in their courses and research. The author illustrates the mathematics with numerous physical examples drawn from contemporary research. In addition to basic subjects such as linear algebra, Fourier analysis, complex variables, differential equations and Bessel functions, this textbook covers topics such as the singular-value decomposition, Lie algebras, the tensors and forms of general relativity, the central limit theorem and Kolmogorov test of statistics, the Monte Carlo methods of experimental and theoretical physics, the renormalization group of condensed-matter physics and the functional derivatives and Feynman path integrals of quantum field theory.

  2. Preference for newspaper size.

    Science.gov (United States)

    Tsang, Steve N H; Hoffmann, Errol R; Chan, Alan H S

    2014-05-01

    The past few years has seen a change in the size of newspapers, with publishers moving to a smaller size format. Five 'standard' newspaper sizes are used in different countries: Broadsheet, Rhensch, Tabloid, Tall Tabloid and Berliner. These papers vary in both width and height of pages and hence there are implications for human reading comfort, which may be dependent on reading location such as on a lounge chair or on a train. Experiments were carried out to determine preferences for the different sizes and to relate these preferences to the geometric characteristics of the newspapers. For both comfortable and cramped/uncomfortable reading conditions, the rank order of preference for paper types was, from least to most-preferred, Broadsheet, Rhensch, Berliner, Tall Tabloid and Tabloid. Preferences were much stronger when determined in cramped/uncomfortable reading conditions, where most comparisons were significantly different. There was good correlation between participant ratings on several scales and preference, where most factors were related to comfort of holding and controlling the paper. PMID:23987982

  3. Size and Reputation

    DEFF Research Database (Denmark)

    Jakobsen, Peter Viggo; Ringsmose, Jens

    2015-01-01

    American public gratitude than the UK. While London has been accused of losing Basra and Musa Qaleh, Copenhagen has been showered with praise and top-posts in NATO. This article explains why demonstrating how the differences in size and reputation gave rise to different expectations of the special...

  4. Calculating Optimal Inventory Size

    Directory of Open Access Journals (Sweden)

    Ruby Perez

    2010-01-01

    Full Text Available The purpose of the project is to find the optimal value for the Economic Order Quantity Model and then use a lean manufacturing Kanban equation to find a numeric value that will minimize the total cost and the inventory size.

  5. Green Lot-Sizing

    NARCIS (Netherlands)

    M. Retel Helmrich (Mathijn Jan)

    2013-01-01

    textabstractThe lot-sizing problem concerns a manufacturer that needs to solve a production planning problem. The producer must decide at which points in time to set up a production process, and when he/she does, how much to produce. There is a trade-off between inventory costs and costs associated

  6. Large litter sizes

    DEFF Research Database (Denmark)

    Sandøe, Peter; Rutherford, K.M.D.; Berg, Peer

    2012-01-01

    This paper presents some key results and conclusions from a review (Rutherford et al. 2011) undertaken regarding the ethical and welfare implications of breeding for large litter size in the domestic pig and about different ways of dealing with these implications. Focus is primarily on the direct...

  7. Size makes a difference

    DEFF Research Database (Denmark)

    Matthiessen, Jeppe; Fagt, Sisse; Biltoft-Jensen, Anja Pia;

    2003-01-01

    increased over time, and in particular in the last 10 years. Study 3: The development in portion sizes of commercial foods has been paralleled by a sharp increase of more than 50% in the sales of sugar-sweetened soft drinks and confectionery like sweets, chocolate and ice creams since the 1970s. Conclusions...

  8. Preference for newspaper size.

    Science.gov (United States)

    Tsang, Steve N H; Hoffmann, Errol R; Chan, Alan H S

    2014-05-01

    The past few years has seen a change in the size of newspapers, with publishers moving to a smaller size format. Five 'standard' newspaper sizes are used in different countries: Broadsheet, Rhensch, Tabloid, Tall Tabloid and Berliner. These papers vary in both width and height of pages and hence there are implications for human reading comfort, which may be dependent on reading location such as on a lounge chair or on a train. Experiments were carried out to determine preferences for the different sizes and to relate these preferences to the geometric characteristics of the newspapers. For both comfortable and cramped/uncomfortable reading conditions, the rank order of preference for paper types was, from least to most-preferred, Broadsheet, Rhensch, Berliner, Tall Tabloid and Tabloid. Preferences were much stronger when determined in cramped/uncomfortable reading conditions, where most comparisons were significantly different. There was good correlation between participant ratings on several scales and preference, where most factors were related to comfort of holding and controlling the paper.

  9. Finite Size Giant Magnon

    CERN Document Server

    Ramadanovic, Bojan

    2008-01-01

    The quantization of the giant magnon away from the infinite size limit is discussed. We argue that this quantization inevitably leads to string theory on a Z_M-orbifold of S^5. This is shown explicitly and examined in detail in the near plane-wave limit.

  10. Sizing Up Visualizations

    DEFF Research Database (Denmark)

    Jakobsen, Mikkel Rønne; Hornbæk, Kasper Anders Søren

    2011-01-01

    Whereas the literature is clear on the benefits of large displays and visualizations, little is known about their combination, that is, how display size affect the usability of visualizations. We describe a controlled experiment where 19 participants used focus+context, overview+detail, and zoomi...

  11. Ultrasound physics.

    Science.gov (United States)

    Shriki, Jesse

    2014-01-01

    Bedside ultrasound has become an important modality for obtaining critical information in the acute care of patients. It is important to understand the physics of ultrasound in order to perform and interpret images at the bedside. The physics of both continuous wave and pulsed wave sound underlies diagnostic ultrasound. The instrumentation, including transducers and image processing, is important in the acquisition of appropriate sonographic images. Understanding how these concepts interplay with each other enables practitioners to obtain the best possible images.

  12. Neutrino Physics

    CERN Document Server

    Xing, Zhi-Zhong

    2014-01-01

    I give a theoretical overview of some basic properties of massive neutrinos in these lectures. Particular attention is paid to the origin of neutrino masses, the pattern of lepton flavor mixing, the feature of leptonic CP violation and the electromagnetic properties of massive neutrinos. I highlight the TeV seesaw mechanisms as a possible bridge between neutrino physics and collider physics in the era characterized by the Large Hadron Collider.

  13. Neutrino Physics

    CERN Document Server

    Romanino, Andrea

    2012-01-01

    These lectures aim at providing a pedagogical overview of neutrino physics. We will mostly deal with standard neutrinos, the ones that are part of the Standard Model of particle physics, and with their standard dynamics, which is enough to understand in a coherent picture most of the rich data available. After introducing the basic theoretical framework, we will illustrate the experimental determination of the neutrino parameters and their theoretical implications, in particular for the origin of neutrino masses.

  14. Quenched effective population size

    CERN Document Server

    Sagitov, Serik; Vatutin, Vladimir

    2010-01-01

    We study the genealogy of a geographically - or otherwise - structured version of the Wright-Fisher population model with fast migration. The new feature is that migration probabilities may change in a random fashion. Applying Takahashi's results on Markov chains with random transition matrices, we establish convergence to the Kingman coalescent, as the population size goes to infinity. This brings a novel formula for the coalescent effective population size (EPS). We call it a quenched EPS to emphasize the key feature of our model - random environment. The quenched EPS is compared with an annealed (mean-field) EPS which describes the case of constant migration probabilities obtained by averaging the random migration probabilities over possible environments.

  15. Fire Size in Tunnels

    OpenAIRE

    Carvel, Ricky O

    2004-01-01

    In recent years, a number of high profile accidental fires have occurred in several road and rail tunnels throughout the world. Many of these fires grew rapidly to catastrophic size and claimed many lives. The processes involved in the rapid growth and extremely severe of these fires are not adequately understood as yet. The introduction to this thesis reviews a number of these accidental fires and describes much of the previous experimental research which has brought about the...

  16. Plasma physics

    CERN Document Server

    Cairns, R A

    1985-01-01

    This book is intended as an introduction to plasma physics at a level suitable for advanced undergraduates or beginning postgraduate students in physics, applied mathematics or astrophysics. The main prerequisite is a knowledge of electromagnetism and of the associated mathematics of vector calculus. SI units are used throughout. There is still a tendency amongst some plasma physics researchers to· cling to C.g.S. units, but it is the author's view that universal adoption of SI units, which have been the internationally agreed standard since 1960, is to be encouraged. After a short introductory chapter, the basic properties of a plasma con­ cerning particle orbits, fluid theory, Coulomb collisions and waves are set out in Chapters 2-5, with illustrations drawn from problems in nuclear fusion research and space physics. The emphasis is on the essential physics involved and (he theoretical and mathematical approach has been kept as simple and intuitive as possible. An attempt has been made to draw attention t...

  17. Physical approaches to biomaterial design

    OpenAIRE

    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...

  18. Aerosol mobility size spectrometer

    Science.gov (United States)

    Wang, Jian; Kulkarni, Pramod

    2007-11-20

    A device for measuring aerosol size distribution within a sample containing aerosol particles. The device generally includes a spectrometer housing defining an interior chamber and a camera for recording aerosol size streams exiting the chamber. The housing includes an inlet for introducing a flow medium into the chamber in a flow direction, an aerosol injection port adjacent the inlet for introducing a charged aerosol sample into the chamber, a separation section for applying an electric field to the aerosol sample across the flow direction and an outlet opposite the inlet. In the separation section, the aerosol sample becomes entrained in the flow medium and the aerosol particles within the aerosol sample are separated by size into a plurality of aerosol flow streams under the influence of the electric field. The camera is disposed adjacent the housing outlet for optically detecting a relative position of at least one aerosol flow stream exiting the outlet and for optically detecting the number of aerosol particles within the at least one aerosol flow stream.

  19. Neoclassical physics

    CERN Document Server

    Cunningham, Mark A

    2015-01-01

    In this introductory text, physics concepts are introduced as a means of understanding experimental observations, not as a sequential list of facts to be memorized. The book is structured around the key scientific discoveries that led to much of our current understanding of the universe. Numerous exercises are provided that utilize Mathematica software to help students explore how the language of mathematics is used to describe physical phenomena. Topics requiring quantum mechanics for a more complete explanation are identified but not pursued. In a departure from the traditional methodology and subject matter used in introductory physics texts, this is organized in a manner that will facilitate a guided discovery style of instruction. Students will obtain much more detailed information about fewer topics and will also gain proficiency with Mathematica, a powerful tool with many potential uses in subsequent courses.

  20. Mathematical physics

    CERN Document Server

    Geroch, Robert

    1900-01-01

    Mathematical Physics is an introduction to such basic mathematical structures as groups, vector spaces, topological spaces, measure spaces, and Hilbert space. Geroch uses category theory to emphasize both the interrelationships among different structures and the unity of mathematics. Perhaps the most valuable feature of the book is the illuminating intuitive discussion of the ""whys"" of proofs and of axioms and definitions. This book, based on Geroch's University of Chicago course, will be especially helpful to those working in theoretical physics, including such areas as relativity, particle

  1. Molecular physics

    CERN Document Server

    Demtröder, Wolfgang

    2008-01-01

    The richly illustrated book comprehensively explains the important principles of diatomic and polyatomic molecules and their spectra in two separate, distinct parts. The first part concentrates on the theoretical aspects of molecular physics, such as the vibration, rotation, electronic states, potential curves, and spectra of molecules. The different methods of approximation for the calculation of electronic wave functions and their energy are also covered. The introduction of basics terms used in group theory and their meaning in molecular physics enables an elegant description of polyatomic

  2. Subjective physics

    OpenAIRE

    Brette, Romain

    2013-01-01

    Imagine a naive organism who does not know anything about the world. It can capture signals through its sensors and it can make actions. What kind of knowledge about the world is accessible to the organism? This situation is analog to that of a physicist trying to understand the world through observations and experiments. In the same way as physics describes the laws of the world obtained in this way by the scientist, I propose to name subjective physics the description of the laws that gover...

  3. Theoretical physics

    International Nuclear Information System (INIS)

    The 1988 progress report of the theoretical Physics Center (Ecole Polytechnique, France), is presented. The research activities are carried out in the fields of the supersymmetry theory, the dynamic systems theory, the statistical mechanics, the plasma physics and the random media. Substantial improvements are obtained on dynamical system investigations. In the field theory, the definition of the Gross-Neveu model is achieved. However the construction of the non-abelian gauge theories and the conformal theories are the main research activities. Concerning Astrophysics, a three-dimensional gravitational code is obtained. The activities of each team, and the list of the published papers, congress communications and thesis are given

  4. The Distribution of Bubble Sizes During Reionization

    CERN Document Server

    Lin, Yin; Furlanetto, Steven R; Sutter, P M

    2015-01-01

    A key physical quantity during reionization is the size of HII regions. Previous studies found a characteristic bubble size which increases rapidly during reionization, with apparent agreement between simulations and analytic excursion set theory. Using four different methods, we critically examine this claim. In particular, we introduce the use of the watershed algorithm -- widely used for void finding in galaxy surveys -- which we show to be an unbiased method with the lowest dispersion and best performance on Monte-Carlo realizations of a known bubble size PDF. We find that a friends-of-friends algorithm declares most of the ionized volume to be occupied by a network of volume-filling regions connected by narrow tunnels. For methods tuned to detect those volume-filling regions, previous apparent agreement between simulations and theory is spurious, and due to a failure to correctly account for the window function of measurement schemes. The discrepancy is already obvious from visual inspection. Instead, HI...

  5. Pictorial Depth Probed through Relative Sizes

    Directory of Open Access Journals (Sweden)

    Johan Wagemans

    2011-12-01

    Full Text Available In the physical environment familiar size is an effective depth cue because the distance from the eye to an object equals the ratio of its physical size to its angular extent in the visual field. Such simple geometrical relations do not apply to pictorial space, since the eye itself is not in pictorial space, and consequently the notion “distance from the eye” is meaningless. Nevertheless, relative size in the picture plane is often used by visual artists to suggest depth differences. The depth domain has no natural origin, nor a natural unit; thus only ratios of depth differences could have an invariant significance. We investigate whether the pictorial relative size cue yields coherent depth structures in pictorial spaces. Specifically, we measure the depth differences for all pairs of points in a 20-point configuration in pictorial space, and we account for these observations through 19 independent parameters (the depths of the points modulo an arbitrary offset, with no meaningful residuals. We discuss a simple formal framework that allows one to handle individual differences. We also compare the depth scale obtained by way of this method with depth scales obtained in totally different ways, finding generally good agreement.

  6. Physics News

    CERN Multimedia

    Gianotti, F.

    In spite of the fact that real data will only come in the year 2006, this is a very busy and interesting time for Physics-related activities. A very short overview of these activities is given in this issue of the ATLAS News Letter, while the various topics will be described in more detail in the next issues. The Physics and Combined Performance groups are working in four main areas: 1) Assess the ATLAS potential for physics, with emphasis on new channels and ideas. Recent examples are Extra-dimensions, invisible Higgs decays, heavy ion physics, the expected potential of a "Super-LHC" running at a luminosity of 10^35, etc.. 2) Improve the understanding of the detector performance and optimise the reconstruction algorithms. Examples of issues in the pipeline are: can we tag charm-jet ? What can we gain in the jet energy resolution by combining the calorimeter and tracker information to reconstruct the jet energy ? 3) Follow detector changes and detector-related issues and monitor the impact on the perform...

  7. Atomic physics

    CERN Document Server

    Born, Max

    1989-01-01

    The Nobel Laureate's brilliant exposition of the kinetic theory of gases, elementary particles, the nuclear atom, wave-corpuscles, atomic structure and spectral lines, electron spin and Pauli's principle, quantum statistics, molecular structure and nuclear physics. Over 40 appendices, a bibliography, numerous figures and graphs.

  8. Motorcycle Physics.

    Science.gov (United States)

    Engel, Chuck; Girard, Barbara

    1983-01-01

    At the end of a secondary school science study of mechanics, a summary lab uses a motorcycle to provide students with the chance to apply some of the concepts they have studied. Exercises from this motorcycle physics lab are discussed. (Author/JN)

  9. Fundamental Physics

    CERN Document Server

    Ydri, Badis

    2016-01-01

    This book includes my lectures, together with their problem sets and solutions, on 1) classical mechanics (one semester), 2) thermodynamics and statistical mechanics (one semester), and 3) quantum mechanics (one semester), which I have been giving to graduate students of theoretical physics at Annaba University since 2010 .

  10. Particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Kamal, Anwar

    2014-09-01

    Provides step-by-step derivations. Contains numerous tables and diagrams. Supports learning and teaching with numerous worked examples, questions and problems with answers. Sketches also the historical development of the subject. This textbook teaches particle physics very didactically. It supports learning and teaching with numerous worked examples, questions and problems with answers. Numerous tables and diagrams lead to a better understanding of the explanations. The content of the book covers all important topics of particle physics: Elementary particles are classified from the point of view of the four fundamental interactions. The nomenclature used in particle physics is explained. The discoveries and properties of known elementary particles and resonances are given. The particles considered are positrons, muon, pions, anti-protons, strange particles, neutrino and hadrons. The conservation laws governing the interactions of elementary particles are given. The concepts of parity, spin, charge conjugation, time reversal and gauge invariance are explained. The quark theory is introduced to explain the hadron structure and strong interactions. The solar neutrino problem is considered. Weak interactions are classified into various types, and the selection rules are stated. Non-conservation of parity and the universality of the weak interactions are discussed. Neutral and charged currents, discovery of W and Z bosons and the early universe form important topics of the electroweak interactions. The principles of high energy accelerators including colliders are elaborately explained. Additionally, in the book detectors used in nuclear and particle physics are described. This book is on the upper undergraduate level.

  11. Zombie physics

    Science.gov (United States)

    Ornes, Stephen

    2016-05-01

    What makes for a fun student project that provides useful results, a journal publication and a high-profile conference talk? Stephen Ornes describes how Alex Alemi and Matt Bierbaum spiced up their learning by mixing statistical physics with their love of zombie tales.

  12. Flipped Physics

    Science.gov (United States)

    Kettle, Maria

    2013-01-01

    This paper defines flipped learning and then examines its practical implementation in AS and A2 level physics classes, that is, classes for 16-18 year olds. The effect of this teaching style on student learning behaviour and its impact on test results are evaluated. The paper recounts the difficulties of implementing it and evaluates student…

  13. After physics

    CERN Document Server

    Albert, David Z

    2015-01-01

    After Physics presents ambitious new essays about some of the deepest questions at the foundations of physics, by the physicist and philosopher David Albert. The book’s title alludes to the close connections between physics and metaphysics, much in evidence throughout these essays. It also alludes to the work of imagining what it would be like for the project of physical science—considered as an investigation into the fundamental laws of nature—to be complete. Albert argues that the difference between the past and the future—traditionally regarded as a matter for metaphysical or conceptual or linguistic or phenomenological analysis—can be understood as a mechanical phenomenon of nature. In another essay he contends that all versions of quantum mechanics that are compatible with the special theory of relativity make it impossible, even in principle, to present the entirety of what can be said about the world as a narrative sequence of “befores” and “afters.” Any sensible and realistic way of...

  14. Particle physics

    International Nuclear Information System (INIS)

    Provides step-by-step derivations. Contains numerous tables and diagrams. Supports learning and teaching with numerous worked examples, questions and problems with answers. Sketches also the historical development of the subject. This textbook teaches particle physics very didactically. It supports learning and teaching with numerous worked examples, questions and problems with answers. Numerous tables and diagrams lead to a better understanding of the explanations. The content of the book covers all important topics of particle physics: Elementary particles are classified from the point of view of the four fundamental interactions. The nomenclature used in particle physics is explained. The discoveries and properties of known elementary particles and resonances are given. The particles considered are positrons, muon, pions, anti-protons, strange particles, neutrino and hadrons. The conservation laws governing the interactions of elementary particles are given. The concepts of parity, spin, charge conjugation, time reversal and gauge invariance are explained. The quark theory is introduced to explain the hadron structure and strong interactions. The solar neutrino problem is considered. Weak interactions are classified into various types, and the selection rules are stated. Non-conservation of parity and the universality of the weak interactions are discussed. Neutral and charged currents, discovery of W and Z bosons and the early universe form important topics of the electroweak interactions. The principles of high energy accelerators including colliders are elaborately explained. Additionally, in the book detectors used in nuclear and particle physics are described. This book is on the upper undergraduate level.

  15. Physics 87

    International Nuclear Information System (INIS)

    A historical review about the physical research in the years 1687, 1887, and 1987 is given. In this connection the confirmation of Newton's Principia by Halley, the Michelson experiment, the discovery of radiowaves by Hertz, and the recent observation of a supernova are mentioned. (HSI).

  16. RHIC physics

    CERN Document Server

    Pajares, C

    1999-01-01

    A brief review of the hadronic phase transitions is presented by emphasizing the physical ideas and the main signatures of the transition in relation to the most significant results of the SPS experiments and the description of the RHIC experiments. (77 refs).

  17. The Physics of Particle Detectors

    Science.gov (United States)

    Green, Dan

    2000-08-01

    Here is a comprehensive introduction to the physical principles and design of particle detectors, covering all major detector types in use today. After discussing the size and energy scales involved in different physical processes, the book considers nondestructive methods, including the photoelectric effect, photomultipliers, scintillators, Cerenkov and transition radiation, scattering and ionization, and the use of magnetic fields in drift and wire chambers. A complete chapter is devoted to silicon detectors. In the final part of the book, Green discusses destructive measurement techniques. Throughout, he emphasizes the physical principles underlying detection and shows, through appropriate examples, how those principles are best utilized in real detectors. Exercises and detailed further reading lists are included.

  18. Heat transfer physics

    CERN Document Server

    Kaviany, Massoud

    2014-01-01

    This graduate textbook describes atomic-level kinetics (mechanisms and rates) of thermal energy storage, transport (conduction, convection, and radiation), and transformation (various energy conversions) by principal energy carriers. The approach combines the fundamentals of molecular orbitals-potentials, statistical thermodynamics, computational molecular dynamics, quantum energy states, transport theories, solid-state and fluid-state physics, and quantum optics. The textbook presents a unified theory, over fine-structure/molecular-dynamics/Boltzmann/macroscopic length and time scales, of heat transfer kinetics in terms of transition rates and relaxation times, and its modern applications, including nano- and microscale size effects. Numerous examples, illustrations, and homework problems with answers that enhance learning are included. This new edition includes applications in energy conversion (including chemical bond, nuclear, and solar), expanded examples of size effects, inclusion of junction quantum tr...

  19. EDITORIAL: Physics competitions Physics competitions

    Science.gov (United States)

    Jordens, H.; Mathelitsch, L.

    2009-11-01

    1. Physics competitions: aims and realizations One aim of physics competitions is to increase the interest of young students, primarily at upper secondary level, to physics and natural sciences in general. A competition has motivational aspects known usually from sports events or games—comparing one's own ability with others, of course with the desire to be better and to win. If competitions reach nationwide and even international levels, additional stimulation is created. Competitions provide greatest attraction to possible winners, to the group of gifted people in a particular field. This implies that science contests are excellent tools for the promotion of talented students. Traditional teaching has been shown to have problems in supporting this group of students. Very often teachers are overstretched with the demands of teaching both low- and high-level students. Extracurricular activities are therefore a good chance to relieve the teacher, and to give talented students the opportunity for appropriate training and challenge. The competitions, however, have a broader impact and address more young people than one might guess from the statements above. Training courses and selection at school level give a larger group of students extra and, to some extent, complimentary education in physics. The degree of complexity of the tasks corresponds very often to the standards of the next level of education in the school system. Interestingly, many physics competitions have their origin in countries beyond the former Iron Curtain. They started as regional and national tournaments, were joined by neighbouring countries and have grown, in some cases, to events with participants from more than 80 countries. Although the features mentioned above are common to the different competitions, there are distinct differences between them [1]. The International Physics Olympiad (IPhO) is the oldest international physics competition for students at upper secondary level [2]. It dates

  20. CDF Top Physics

    Science.gov (United States)

    Tartarelli, G. F.; CDF Collaboration

    1996-05-01

    The authors present the latest results about top physics obtained by the CDF experiment at the Fermilab Tevatron collider. The data sample used for these analysis (about 110 pb{sup{minus}1}) represents almost the entire statistics collected by CDF during four years (1992--95) of data taking. This large data size has allowed detailed studies of top production and decay properties. The results discussed here include the determination of the top quark mass, the measurement of the production cross section, the study of the kinematics of the top events and a look at top decays.

  1. Physical Properties of Nanosystems

    CERN Document Server

    Bonca, Janez

    2011-01-01

    Recent advances in nanoscience have demonstrated that fundamentally new physical phenomena are found when systems are reduced to sizes comparable to the fundamental microscopic length scales of the material investigated. There has been great interest in this research due, in particular, to its role in the development of spintronics, molecular electronics and quantum information processing. The contributions to this volume describe new advances in many of these fundamental and fascinating areas of nanophysics, including carbon nanotubes, graphene, magnetic nanostructures, transport through coupled quantum dots, spintronics, molecular electronics, and quantum information processing.

  2. Interaction between Physics and Cosmology

    OpenAIRE

    Panchapakesan, N.

    2005-01-01

    Recent results indicate the presence of a cosmological constant (or related dark energy) in the universe. It has been conjectured recently that the interaction parameters of physical theories may be dependant on the size parameter of the universe, related to the cosmological constant. We investigate whether such effects will help in explaining baryogenesis in early universe. They do seem to succeed.

  3. Mastering physics

    CERN Multimedia

    2006-01-01

    CERN hosts a series of videoconference masterclasses for high-school students. A screen shot of part of the masterclasses videoconference. For two weeks in the middle of March CERN played host to a series of videoconferences as part of the European Particle Physics Masterclasses 2006. The masterclasses were organized for the second consecutive year by ATLAS physicist Michael Kobel from the Technical University of Dresden and colleagues from the European Particle Physics Outreach Group (EPPOG), and more than 3100 high-school students from the United States and 17 countries in Europe participated. On each of the 14 days, between four and six universities hosted groups of students, providing introductory lectures, institute tours and hands-on exercises including the popular 'Hands on CERN' package for analyzing LEP data. To support these events, a CD containing material in 16 languages was distributed to every student. As a grand finale of the day, the groups of students connected to CERN for a videoconference,...

  4. Terahertz physics

    CERN Document Server

    Lewis, R A

    2012-01-01

    Terahertz physics covers one of the least explored but richest regions of the electromagnetic spectrum. Designed for independent learning, this is the first book to open up this exciting new field to students of science and engineering. Written in a clear and consistent style, the textbook focuses on an understanding of fundamental physical principles at terahertz frequencies and their applications. Part I outlines the foundations of terahertz science, starting with the mathematical representation of oscillations before exploring terahertz-frequency light, terahertz phenomena in matter and the terahertz interactions between light and matter. Part II covers components of terahertz technology, from sources of terahertz frequency radiation, through the manipulation of the radiation, to its detection. Part III deals with applications, including time-domain spectroscopy. Highlighting modern developments and concepts, the book is ideal for self-study. It features precise definitions, clear explanations, instructive...

  5. Particle physics

    CERN Document Server

    Kennedy, Eugene

    2012-01-01

    Stimulated by the Large Hadron Collider and the search for the elusive Higgs Boson, interest in particle physics continues at a high level among scientists and the general public. This book includes theoretical aspects, with chapters outlining the generation model and a charged Higgs boson model as alternative scenarios to the Standard Model. An introduction is provided to postulated axion photon interactions and associated photon dispersion in magnetized media. The complexity of particle physics research requiring the synergistic combination of theory, hardware and computation is described in terms of the e-science paradigm. The book concludes with a chapter tackling potential radiation hazards associated with extremely weakly interacting neutrinos if produced in copious amounts with future high-energy muon-collider facilities.

  6. Physical hydrodynamics

    CERN Document Server

    Guyon, Etienne; Petit, Luc; Mitescu, Catalin D

    2015-01-01

    This new edition is an enriched version of the textbook of fluid dynamics published more than 10 years ago. It retains the same physically oriented pedagogical perspective. This book emphasizes, as in the first edition, experimental inductive approaches and relies on the study of the mechanisms at play and on dimensional analysis rather than more formal approaches found in many classical textbooks in the field. The need for a completely new version also originated from the increase, over the last few decades, of the cross-overs between the mechanical and physical approaches, as is visible in international meetings and joint projects. Hydrodynamics is more widely linked today to other fields of experimental sciences: materials, environment, life sciences and earth sciences, as well as engineering sciences.

  7. Reactor Physics

    Energy Technology Data Exchange (ETDEWEB)

    Ait Abderrahim, A

    2001-04-01

    The Reactor Physics and MYRRHA Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis of reactor fuel. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2000 are summarised.

  8. Astroparticle physics

    Science.gov (United States)

    Ong, Rene A.

    2013-12-01

    Astroparticle physics is a rapidly developing field that has a high degree of overlap with particle physics and astronomy. This paper summarizes recent results and leading experiments in two selected areas: very high energy astrophysics and dark matter. Both areas have made great progress in the last 5 years due to improved instrumentation and a growing community. In very high energy astrophysics, many sources of GeV and TeV radiation have been detected and the challenge now is to fully understand the processes involved at these sites of extreme particle acceleration. In the area of dark matter, there is a close scientific connection between astroparticle experiments and the Large Hadron Collider (LHC). The combination of the LHC, direct-detection and indirect-detection experiments provide critical complementarity and unprecedented sensitivity in the quest to understand this deep mystery.

  9. Quantum physics

    CERN Document Server

    Scheck, Florian

    2013-01-01

    Scheck’s Quantum Physics presents a comprehensive introductory treatment, ideally suited for a two-semester course. Part One covers the basic principles and prime applications of quantum mechanics, from the uncertainty relations to many-body systems. Part Two introduces to relativistic quantum field theory and ranges from symmetries in quantum physics to electroweak interactions. Numerous worked-out examples as well as exercises, with solutions or hints, enables the book’s use as an accompanying text for courses, and also for independent study. For both parts, the necessary mathematical framework is treated in adequate form and detail. The book ends with appendices covering mathematical fundamentals and enrichment topics, plus selected biographical notes on pioneers of quantum mechanics and quantum field theory. The new edition was thoroughly revised and now includes new sections on quantization using the path integral method and on deriving generalized path integrals for bosonic and fermionic fields.

  10. EDITORIAL: Physics competitions Physics competitions

    Science.gov (United States)

    Jordens, H.; Mathelitsch, L.

    2011-07-01

    International tests on competences, such as TIMSS or PISA, and knowledge of young students have revealed low average scores in many countries, often unexpectedly. One effective measure to increase the average standard of a population is to bring the last third of the group to a higher level. Therefore, many nations put some effort into this activity. This brings the danger that not enough attention is paid to students at the other end, those who are talented. Indeed, it is a very difficult task for a teacher to support the less able and at the same time challenge the gifted students, to lead them to the limits of their abilities and provide for a smooth transition to university study. Physics competitions have been proven to fulfil these last demands to a large degree, and therefore are an important additional and, to some extent, complementary tool for the promotion of talented students. This third special section on physics competitions in European Journal of Physics contains three papers, each dealing with a different form of science contest. The first continues the series of presentations of tasks performed at the International Young Physicists' Tournament, which was held in Vienna in 2011. First place went to the team from Singapore, and they have put their investigation on vertical oscillations of coupled magnets into written form (not required by the tournament, where an oral presentation and a defence and discussion are the central aspects). Their paper shows how rich in physics this problem is, and what level of solutions high-school students can already achieve. Sadly, those responsible for the organization of last year's International Physics Olympiad did not provide us with a report on this competition. This is unfortunate, since the Olympiad in Zagreb was very successful and, in particular, the experimental tasks were creative and demanding. Very similar to the aims and the execution of the Physics Olympiad is the International Olympiad on Astronomy

  11. Exotic Physics

    CERN Document Server

    Sigamani, Michael

    2016-01-01

    A selection of results for searches for exotic physics at the LHC are presented. These include a search for massive resonances, dark matter with a high energy jet in association with large missing transverse momentum, long-lived neutral particles, and narrow dijet resonances. The results are based on 20/fb of LHC proton-proton collisions at sqrt(s) = 8 TeV taken with the CMS detector.

  12. Physical properties of fertilizer in relation to handling and spreading.

    NARCIS (Netherlands)

    Hofstee, J.W.

    1993-01-01

    The influence of physical properties of fertilizer on the handling and spreading is studied. The reviewed properties are particle size and particle size distribution, coefficient of friction, coefficient of restitution, particle strength and aerodynamic resistance. Further a measuring procedure base

  13. Solar Physics - Plasma Physics Workshop

    Science.gov (United States)

    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.

  14. Dependency of Lipid Raft Diffusion on System Size

    Science.gov (United States)

    Davis, Ryan

    2009-11-01

    An inherit limitation in molecular dynamics is a finite system size. Although periodic boundary conditions can be used to mimic an infinite space, minimizing the artificial effects created by the physical dimensions of the system still remains an issue. Here I will discuss the undesirable relationship between system properties and system size observed via a dissipative particle dynamics approach. In particular, results illustrate a strong dependence between the diffusion of a lipid raft along a membrane and the length of the axis perpendicular to it, even at relatively large system sizes. Methods for obtaining system properties independently of simulation size are crucial for accurate results.

  15. Dependence of strength on particle size in graphite

    International Nuclear Information System (INIS)

    The strength to particle size relationship for specially fabricated graphites has been demonstrated and rationalized using fracture mechanics. In the past, similar studies have yielded empirical data using only commercially available material. Thus, experimental verification of these relationships has been difficult. However, the graphites of this study were fabricated by controlling the particle size ranges for a series of isotropic graphites. All graphites that were evaluated had a constant 1.85 g/cm3 density. Thus, particle size was the only variable. This study also considered the particle size effect on other physical properties; coefficient of thermal expansion (CTE), electrical resistivity, fracture strain, and Young's modulus

  16. Effect Sizes, Confidence Intervals, and Confidence Intervals for Effect Sizes

    Science.gov (United States)

    Thompson, Bruce

    2007-01-01

    The present article provides a primer on (a) effect sizes, (b) confidence intervals, and (c) confidence intervals for effect sizes. Additionally, various admonitions for reformed statistical practice are presented. For example, a very important implication of the realization that there are dozens of effect size statistics is that "authors must…

  17. Women in Physics.

    Science.gov (United States)

    Roth, Laura M.; O'Fallon, Nancy M.

    This booklet presents information about career opportunities for women in physics. Included are summaries of research areas in physics (optical physics, solid-state physics, materials science, nuclear physics, high-energy physics, astrophysics, cryogenics, plasma physics, biophysics, atmospheric physics) and differences between theory and…

  18. Italian Society of Physics

    International Nuclear Information System (INIS)

    The abstracts of most of the papers read at the 53 National Congress of the Italian Society of Physics are presented. The Congress developed in ten sessions: high energy and elementary particle physics, physics of nuclei, condensed matter, quantum electronics, cosmic physics, geophysics, general physics, electronics and applied physics, health physics and hystory of physics. An author index is also included

  19. Physical protection

    Energy Technology Data Exchange (ETDEWEB)

    Myre, W.C.; DeMontmollin, J.M. (Sandia National Labs., Albuquerque, NM (USA))

    1989-07-01

    Serious concern about physical protection of nuclear facilities began around 1972. R and D was initiated at Sandia National Laboratories which had developed techniques to protect weapons for many years. Special vehicles, convoy procedures, and a communications system previously developed for weapons shipments were improved and extended for shipments of other sensitive materials. Barriers, perimeter alarms, portal and internal control systems were developed, tested, and published in handbooks and presented at symposia. Training programs were initiated for U.S. and foreign personnel. Containment and surveillance techniques were developed for the IAEA. Presently emphasis is on computer security, active barriers, and techniques to prevent theft or sabotage by insiders .

  20. Theoretical physics

    CERN Document Server

    Joos, Georg

    1986-01-01

    Among the finest, most comprehensive treatments of theoretical physics ever written, this classic volume comprises a superb introduction to the main branches of the discipline and offers solid grounding for further research in a variety of fields. Students will find no better one-volume coverage of so many essential topics; moreover, since its first publication, the book has been substantially revised and updated with additional material on Bessel functions, spherical harmonics, superconductivity, elastomers, and other subjects.The first four chapters review mathematical topics needed by theo

  1. Particle physics

    International Nuclear Information System (INIS)

    The two main themes of this volume are the standard model of the fundamental interactions (and beyond) and astrophysics. The remarkable advances in the theoretical understanding and experimental confirmation of the standard model were reviewed in several lectures where the reader will find a thorough analysis of recent experiments as well as a detailed comparison of the standard model with experiment. On a more theoretical side, supersymmetry, supergravity and strings were discussed as well. The second theme concerns astrophysics where the school was quite successful in bridging the gap between this fascinating subject and more conventional particle physics

  2. Plasma physics

    International Nuclear Information System (INIS)

    This report contains the papers delivered at the AEB - Natal University summer school on plasma physics held in Durban during January 1979. The following topics were discussed: Tokamak devices; MHD stability; trapped particles in tori; Tokamak results and experiments; operating regime of the AEB Tokamak; Tokamak equilibrium; high beta Tokamak equilibria; ideal Tokamak stability; resistive MHD instabilities; Tokamak diagnostics; Tokamak control and data acquisition; feedback control of Tokamaks; heating and refuelling; neutral beam injection; radio frequency heating; nonlinear drift wave induced plasma transport; toroidal plasma boundary layers; microinstabilities and injected beams and quasilinear theory of the ion acoustic instability

  3. Atomic physics

    International Nuclear Information System (INIS)

    Research activities in atomic physics at Lawrence Berkeley Laboratory during 1976 are described. Topics covered include: experiments on stored ions; test for parity violation in neutral weak currents; energy conservation and astrophysics; atomic absorption spectroscopy, atomic and molecular detectors; theoretical studies of quantum electrodynamics and high-z ions; atomic beam magnetic resonance; radiative decay from the 23Po,2 levels of helium-like argon; quenching of the metastable 2S/sub 1/2/ state of hydrogen-like argon in an external electric field; and lifetime of the 23Po level of helium-like krypton

  4. Flipped physics

    Science.gov (United States)

    Kettle, Maria

    2013-09-01

    This paper defines flipped learning and then examines its practical implementation in AS and A2 level physics classes, that is, classes for 16-18 year olds. The effect of this teaching style on student learning behaviour and its impact on test results are evaluated. The paper recounts the difficulties of implementing it and evaluates student preferences. It concludes with comments about this teaching style’s appropriateness for various groups of students and identifies those for whom it is not suitable. A list of useful websites is included.

  5. Hadron physics

    International Nuclear Information System (INIS)

    Is all hadronic physics ultimately describable by QCD. Certainly, many disparate phenomena can be understood within the QCD framework. Also certainly, there are important questions which are open, both theoretically (little guidance, as yet) and experimentally, regarding confinement. Are there dibaryons, baryonium, glueballs. In addition, there are experimental results which at present do not have an explanation. This talk, after a short section on QCD successes and difficulties, will emphasize two experimental topics which have recent results - glueball spectroscopy and exclusive reactions at large momentum transfer. Both are experimentally accessible in the AGS/LAMPF II/AGS II/TRIUMF II/SIN II energy domain

  6. Large Size Telescope Report

    CERN Document Server

    Mazin, D; Teshima, M

    2016-01-01

    The Cherenkov Telescope Array (CTA) observatory will be deployed over two sites in the two hemispheres. Both sites will be equipped with four Large Size Telescopes (LSTs), which are crucial to achieve the science goals of CTA in the 20-200 GeV energy range. Each LST is equipped with a primary tessellated mirror dish of 23 m diameter, supported by a structure made mainly of carbon fibre reinforced plastic tubes and aluminum joints. This solution guarantees light weight (around 100 tons), essential for fast repositioning to any position in the sky in <20 seconds. The camera is composed of 1855 photomultiplier tubes and embeds the control, readout and trigger electronics. The detailed design is now complete and production of the first LST, which will serve as a prototype for the remaining seven, is ongoing. The installation of the first LST at the Roque de los Muchachos Observatory on the Canary island of La Palma (Spain) started in July 2016. In this paper we will outline the technical solutions adopted to f...

  7. Recombination rate predicts inversion size in Diptera.

    Science.gov (United States)

    Cáceres, M; Barbadilla, A; Ruiz, A

    1999-09-01

    Most species of the Drosophila genus and other Diptera are polymorphic for paracentric inversions. A common observation is that successful inversions are of intermediate size. We test here the hypothesis that the selected property is the recombination length of inversions, not their physical length. If so, physical length of successful inversions should be negatively correlated with recombination rate across species. This prediction was tested by a comprehensive statistical analysis of inversion size and recombination map length in 12 Diptera species for which appropriate data are available. We found that (1) there is a wide variation in recombination map length among species; (2) physical length of successful inversions varies greatly among species and is inversely correlated with the species recombination map length; and (3) neither the among-species variation in inversion length nor the correlation are observed in unsuccessful inversions. The clear differences between successful and unsuccessful inversions point to natural selection as the most likely explanation for our results. Presumably the selective advantage of an inversion increases with its length, but so does its detrimental effect on fertility due to double crossovers. Our analysis provides the strongest and most extensive evidence in favor of the notion that the adaptive value of inversions stems from their effect on recombination.

  8. EDITORIAL: Physics competitions Physics competitions

    Science.gov (United States)

    Jordens, H.; Mathelitsch, L.

    2010-07-01

    This editorial opens the second special section on physics competitions in European Journal of Physics. In the first section last year, we asked for feedback on the idea of such a section and on the content of the articles. We received no answer whatsoever, which can be interpreted in two ways: the section is not interesting enough to raise motivation for feedback, or the reader is satisfied. Having no indication which scenario is the correct one, we are optimistic and favour the second. The section at hand contains three articles. Again, as last year, the organizer of the annual Olympiad reports on tasks and outcomes of this competition. The Olympiad took place in Merida, Mexico, and was by far the largest event with 316 contestants from 68 countries. Again, the predominance of Asian/Chinese students was manifest, showing how serious the training is taken by both their authorities and students. Unfortunately, the winners of the last International Young Physicists' Tournament (IYPT), the team from Korea, did not accept the offer to report on their prize-winning contribution. We are thankful that two students from Austria, who achieved second place with their team, took over and reported on the task which they presented in the finals of the competition. It connects the fields of sport and physics and explains a special move in skateboarding. The third contribution introduces a different competition, 'International Conference of Young Scientists'. On one hand, as in the Olympiad, it addresses individuals, not teams. On the other, as in the IYPT, students have several months to prepare and also the quality of the presentation is an important element of the judgment. In fact, this competition comes closer to real scientific research compared to the other events. Finally and again, we hope that this section will serve several purposes: To show the competitions as a very important tool in the support of gifted students. To raise awareness amongst university teachers, and

  9. Physical Activity (Exercise)

    Science.gov (United States)

    ... Our ePublications > Physical activity (exercise) fact sheet ePublications Physical activity (exercise) fact sheet How can physical activity improve ... Have had recent hip surgery More information on physical activity (exercise) For more information about physical activity (exercise), ...

  10. Laser damage dependence on the size and concentration of precursor defects in KDP crystals: view through differently sized filter pores.

    Science.gov (United States)

    Wang, Yueliang; Zhao, Yuanan; Xie, Xiaoyi; Hu, Guohang; Yang, Liujiang; Xu, Ziyuan; Shao, Jianda

    2016-04-01

    We investigate the laser-induced damage performance at 1064 nm of potassium dihydrogen phosphate (KDP) crystals grown using filters of different pore sizes. The aim is to explore a novel method for understanding laser-matter interactions with regard to physical parameters affecting the ability of damage precursors to initiate damage. By reducing the pore size of filters in continuous filtration growth, we can improve laser damage resistance. Furthermore, we develop a model based on a Gaussian distribution of precursor thresholds and heat transfer to obtain a size distribution of the precursor defects. Smaller size and/or lower concentration of precursor defects could lead to better damage resistance. PMID:27192280

  11. PHYSICAL PROPERTIES OF CORN RESIDUES

    Directory of Open Access Journals (Sweden)

    Yaning Zhang

    2012-01-01

    Full Text Available Corn residues (cobs, leaves and stalks are abundantly available renewable materials that can be used as an energy source in gasification and combustion systems. Proper understanding of the physical properties of these materials is necessary for their use in thermochemical conversion processes. The physical properties (moisture content, particle size, bulk density and porosity of corn cobs, leaves and stalks were determined in this study. The moisture contents were 6.38, 7.92 and 6.40% of the cobs, leaves and stalks, respectively. The cobs had the highest weight percentage (18.23% of the small particles (0.850 mm. Most of the stalk particles (84.82% were in the range of 0.212-0.850 mm. The cob particle size had a normal concave (inward distribution between particle sizes 0.106 mm (18.23 weight % and 0.925 mm (25.26 weight % with the lowest weight percentage (5.30 weight % at 0.390 mm particle size while the stalk particle size had a normal convex (outward distribution between particle sizes 0.106 mm (8.49 weight % and 0.925 mm (6.69 weight % with the highest weight percentage (23.47 weight % at the 0.605 mm particle size. The leaves had an increasing trend of particle size distribution between the particle sizes 0.106 and 0.925 mm. The average particle sizes for the cobs, leaves and stalks were 0.56, 0.70 and 0.49 mm, respectively. The average bulk density was 282.38, 81.61 and 127.32 kg m-3 for the corn cobs, leaves and stalks, respectively. The average porosity was 67.93, 86.06 and 58.51% for the corn cobs, leaves and stalks, respectively. A positive relationship between the average particle size and the porosity was observed for the corn residues. The differences in the physical properties among the corn residues (cobs, leaves and stalks observed in this study are due to variations in the compositions and structures of these materials.

  12. Calculating body frame size (image)

    Science.gov (United States)

    ... boned category. Determining frame size: To determine the body frame size, measure the wrist with a tape measure and use the following chart to determine whether the person is small, medium, or large boned. Women: Height under 5'2" Small = wrist size less ...

  13. Exploiting Size-Dependent Drag and Magnetic Forces for Size-Specific Separation of Magnetic Nanoparticles

    OpenAIRE

    Hunter B. Rogers; Tareq Anani; Young Suk Choi; Beyers, Ronald J.; David, Allan E.

    2015-01-01

    Realizing the full potential of magnetic nanoparticles (MNPs) in nanomedicine requires the optimization of their physical and chemical properties. Elucidation of the effects of these properties on clinical diagnostic or therapeutic properties, however, requires the synthesis or purification of homogenous samples, which has proved to be difficult. While initial simulations indicated that size-selective separation could be achieved by flowing magnetic nanoparticles through a magnetic field, sub...

  14. Continuum Physics

    CERN Document Server

    Hertel, Peter

    2012-01-01

    This small book on the properties of continuously distributed matter covers a huge field. It sets out the governing principles of continuum physics and illustrates them by carefully chosen examples. These examples comprise structural mechanics and elasticity, fluid media, electricity and optics, thermoelectricity, fluctuation phenomena and more, from Archimedes' principle via Brownian motion to white dwarfs. Metamaterials, pattern formation by reaction-diffusion and surface plasmon polaritons are dealt with as well as classical topics such as Stokes' formula, beam bending and buckling, crystal optics and electro- and magnetooptic effects, dielectric waveguides, Ohm's law, surface acoustic waves, to mention just some.   The set of balance equations for content, flow and production of particles, mass, charge, momentum, energy and entropy is augmented by material, or constitutive equations. They describe entire classes of materials, such as viscid fluids and gases, elastic media, dielectrics or electrical con...

  15. LHC Physics

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    From quarks to yet unknown particles, CERN continues to explore new frontiers in physics. Thanks to some of the most complex instruments ever made in a laboratory, Nature can reveal its inner secrets to the scientists.   Mass is the amount of material in an object. Newton showed us that weight is proportional to mass, and Einstein showed that energy is related to mass through the famous equation E = mc2. When it comes to elementary particles, physicists are dealing with a very fundamental question: where does the mass come from?  Why do particles with no known structure have mass? The answer may lie in the so-called Higgs mechanism. According to this theory, a medium - called the Higgs field - spreads through all the Universe at all times. Particles acquire their mass by interacting with this field, such that those that interact strongly are heavier than those having a weaker interaction. The Higgs boson is th...

  16. DUNE Physics

    Energy Technology Data Exchange (ETDEWEB)

    Strait, James [Fermilab

    2015-08-01

    The Deep Underground Neutrino Experiment is a worldwide effort to build a next-generation long-baseline neutrino experiment with a neutrino beam and near detector at Fermilab and a far detector at the Sanford Underground Research Facility 1,300 km from Fermilab. It is a merger of previous efforts and other interested parties to build, operate and exploit a staged 40-kt liquid argon detector and a high precision near detector exposed to a high-power, broad-band neutrino beam. The goals of the experiment are precision oscillation measurements, including CP violation and neutrino mass hierarchy determination, search for nucleon decay, and neutrino astrophysics, as well as precision neutrino physics at the near site.

  17. Atomic physics

    Energy Technology Data Exchange (ETDEWEB)

    Livingston, A.E.; Kukla, K.; Cheng, S. [Univ. of Toledo, OH (United States)] [and others

    1995-08-01

    In a collaboration with the Atomic Physics group at Argonne and the University of Toledo, the Atomic Physics group at the University of Notre Dame is measuring the fine structure transition energies in highly-charged lithium-like and helium-like ions using beam-foil spectroscopy. Precise measurements of 2s-2p transition energies in simple (few-electron) atomic systems provide stringent tests of several classes of current atomic- structure calculations. Analyses of measurements in helium-like Ar{sup 16+} have been completed, and the results submitted for publication. A current goal is to measure the 1s2s{sup 3}S{sub 1} - 1s2p{sup 3}P{sub 0} transition wavelength in helium-like Ni{sup 26+}. Measurements of the 1s2s{sup 2}S{sub 1/2} - 1s2p{sup 2}P{sub 1/2,3/2} transition wavelengths in lithium-like Kr{sup 33+} is planned. Wavelength and lifetime measurements in copper-like U{sup 63+} are also expected to be initiated. The group is also participating in measurements of forbidden transitions in helium-like ions. A measurement of the lifetime of the 1s2s{sup 3}S{sub 1} state in Kr{sup 34+} was published recently. In a collaboration including P. Mokler of GSI, Darmstadt, measurements have been made of the spectral distribution of the 2E1 decay continuum in helium-like Kr{sup 34+}. Initial results have been reported and further measurements are planned.

  18. Nuclear Sizes and the Isotope Shift

    CERN Document Server

    Friar, J L; Sprung, D W L

    1997-01-01

    Darwin-Foldy nuclear-size corrections in electronic atoms and nuclear radii are discussed from the nuclear-physics perspective. Interpretation of precise isotope-shift measurements is formalism dependent, and care must be exercised in interpreting these results and those obtained from relativistic electron scattering from nuclei. We strongly advocate that the entire nuclear-charge operator be used in calculating nuclear-size corrections in atoms, rather than relegating portions of it to the non-radiative recoil corrections. A preliminary examination of the intrinsic deuteron radius obtained from isotope-shift measurements suggests the presence of small meson-exchange currents (exotic binding contributions of relativistic order) in the nuclear charge operator, which contribute approximately 1/2%.

  19. Conceptualization of relative size by honeybees

    Directory of Open Access Journals (Sweden)

    Aurore eAvargues-Weber

    2014-03-01

    Full Text Available The ability to process visual information using relational rules allows for decisions independent of the specific physical attributes of individual stimuli. Until recently, the manipulation of relational concepts was considered as a prerogative of large mammalian brains. Here we show that individual free flying honeybees can learn to use size relationship rules to choose either the larger or smaller stimulus as the correct solution in a given context, and subsequently apply the learnt rule to novel colors and shapes providing that there is sufficient input to the long wavelength (green photoreceptor channel. Our results add a novel, size-based conceptual rule to the set of relational concepts that honeybees have been shown to master and underline the value of bees as an animal model for studying the emergence of conceptualization abilities.

  20. Amostragem e variabilidade espacial de atributos físicos de um latossolo vermelho em Mossoró, RN Sampling size and spatial variability of physical attributes of an arenic kandiustults in Mossoró, Rio Grande do Norte State, Brazil

    Directory of Open Access Journals (Sweden)

    Joaquim Amaro Filho

    2007-06-01

    Full Text Available Os solos, mesmo aqueles considerados homogêneos, exibem alguma variabilidade espacial e temporal em seus atributos físicos, químicos e biológicos. A definição dessa variabilidade é muito importante para um eficiente manejo do solo. Este trabalho objetivou estudar a variabilidade espacial de alguns atributos físicos de um Latossolo Vermelho, em Mossoró-RN, a fim de estabelecer o melhor procedimento na coleta de amostras de solo. Em uma área com dimensões de 100 x 100 m, marcada a cada 10 m em duas direções perpendiculares entre si, fez-se a coleta de amostras de solo na camada de 0,0-0,2 m de profundidade, totalizando 100 amostras. As análises compreenderam granulometria, densidade do solo, densidade de partículas, porosidade total e retenção de água nas tensões de 0,033 e 1,500 MPa. Os dados foram analisados por estatística descritiva e geoestatística. Concluiu-se que a variabilidade do solo, medida pelo coeficiente de variação, mostrou-se baixa para areia, densidade do solo, densidade de partículas e volume total de poros e média para silte, argila, capacidade de campo e ponto de murcha permanente; a maioria das variáveis analisadas segue distribuição normal de freqüências, excetuando-se areia, densidade do solo e volume total de poros; o mapeamento das variáveis estudadas sugere o estabelecimento de subáreas homogêneas, a fim de tornar o manejo dos recursos mais eficiente, especialmente o de água.The soils, some those considered homogenous, show some spatial and temporal variability of its physical, chemical and biological atributes. To define this variability is very important to efficient soil management. This study had the objective of investigating the spatial variability of some physical attributes of an Red Latosol in Mossoró, state of Rio Grande do Norte, Brazil, to determine the best procedure for soil sampling. Soil samples were collected on a 100 x 100 m area, in 10 m grid marking, from the 0-0.2 m

  1. The Cherenkov Telescope Array Large Size Telescope

    CERN Document Server

    Ambrosi, G; Baba, H; Bamba, A; Barceló, M; de Almeida, U Barres; Barrio, J A; Bigas, O Blanch; Boix, J; Brunetti, L; Carmona, E; Chabanne, E; Chikawa, M; Colin, P; Conteras, J L; Cortina, J; Dazzi, F; Deangelis, A; Deleglise, G; Delgado, C; Díaz, C; Dubois, F; Fiasson, A; Fink, D; Fouque, N; Freixas, L; Fruck, C; Gadola, A; García, R; Gascon, D; Geffroy, N; Giglietto, N; Giordano, F; Grañena, F; Gunji, S; Hagiwara, R; Hamer, N; Hanabata, Y; Hassan, T; Hatanaka, K; Haubold, T; Hayashida, M; Hermel, R; Herranz, D; Hirotani, K; Inoue, S; Inoue, Y; Ioka, K; Jablonski, C; Kagaya, M; Katagiri, H; Kishimoto, T; Kodani, K; Kohri, K; Konno, Y; Koyama, S; Kubo, H; Kushida, J; Lamanna, G; Flour, T Le; López-Moya, M; López, R; Lorenz, E; Majumdar, P; Manalaysay, A; Mariotti, M; Martínez, G; Martínez, M; Mazin, D; Miranda, J M; Mirzoyan, R; Monteiro, I; Moralejo, A; Murase, K; Nagataki, S; Nakajima, D; Nakamori, T; Nishijima, K; Noda, K; Nozato, A; Ohira, Y; Ohishi, M; Ohoka, H; Okumura, A; Orito, R; Panazol, J L; Paneque, D; Paoletti, R; Paredes, J M; Pauletta, G; Podkladkin, S; Prast, J; Rando, R; Reimann, O; Ribó, M; Rosier-Lees, S; Saito, K; Saito, T; Saito, Y; Sakaki, N; Sakonaka, R; Sanuy, A; Sasaki, H; Sawada, M; Scalzotto, V; Schultz, S; Schweizer, T; Shibata, T; Shu, S; Sieiro, J; Stamatescu, V; Steiner, S; Straumann, U; Sugawara, R; Tajima, H; Takami, H; Tanaka, S; Tanaka, M; Tejedor, L A; Terada, Y; Teshima, M; Totani, T; Ueno, H; Umehara, K; Vollhardt, A; Wagner, R; Wetteskind, H; Yamamoto, T; Yamazaki, R; Yoshida, A; Yoshida, T; Yoshikoshi, T

    2013-01-01

    The two arrays of the Very High Energy gamma-ray observatory Cherenkov Telescope Array (CTA) will include four Large Size Telescopes (LSTs) each with a 23 m diameter dish and 28 m focal distance. These telescopes will enable CTA to achieve a low-energy threshold of 20 GeV, which is critical for important studies in astrophysics, astroparticle physics and cosmology. This work presents the key specifications and performance of the current LST design in the light of the CTA scientific objectives.

  2. On size and growth of cells

    CERN Document Server

    Boudaoud, A

    2002-01-01

    Understanding how growth induces form is a longstanding biological question. Many studies concentrated on the shapes of plant cells, fungi or bacteria. Some others have shown the importance of the mechanical properties of bacterial walls and plant tissues in pattern formation. Here I sketch a simple physical picture of cell growth. The study is focussed on isolated cells that have walls. They are modeled as thin elastic shells containing a liquid, which pressure drives the growth as generally admitted for bacteria or plant cells. Requiring mechanical equilibrium leads to estimations of typical cell sizes, in quantitative agreement with compiled data including bacteria, cochlear outer hair, fungi, yeast, root hair and giant alga cells.

  3. Physics objects for top physics in ATLAS

    CERN Document Server

    Hawkings, Richard John; The ATLAS collaboration

    2016-01-01

    This talk reviews the reconstruction and calibration of physics objects in ATLAS as they are applied to top quark physics. Examples of the precision attainable and the resulting uncertainties on key top physics measurements are also given.

  4. Asymptotic size determines species abundance in the marine size spectrum

    DEFF Research Database (Denmark)

    Andersen, Ken Haste; Beyer, Jan

    2006-01-01

    The majority of higher organisms in the marine environment display indeterminate growth; that is, they continue to grow throughout their life, limited by an asymptotic size. We derive the abundance of species as a function of their asymptotic size. The derivation is based on size-spectrum theory......, where population structure is derived from physiology and simple arguments regarding the predator-prey interaction. Using a hypothesis of constant satiation, which states that the average degree of satiation is independent of the size of an organism, the number of individuals with a given size is found...... to be proportional to the weight raised to the power -2.05, independent of the predator/prey size ratio. This is the first time the spectrum exponent has been derived solely on the basis of processes at the individual level. The theory furthermore predicts that the parameters in the von Bertalanffy growth function...

  5. Polymer physics

    CERN Document Server

    Gedde, Ulf W

    1999-01-01

    This book is the result of my teaching efforts during the last ten years at the Royal Institute of Technology. The purpose is to present the subject of polymer physics for undergraduate and graduate students, to focus the fundamental aspects of the subject and to show the link between experiments and theory. The intention is not to present a compilation of the currently available literature on the subject. Very few reference citations have thus been made. Each chapter has essentially the same structure: starling with an introduction, continuing with the actual subject, summarizing the chapter in 30D-500 words, and finally presenting problems and a list of relevant references for the reader. The solutions to the problems presented in Chapters 1-12 are given in Chapter 13. The theme of the book is essentially polymer science, with the exclusion of that part dealing directly with chemical reactions. The fundamentals in polymer science, including some basic polymer chemistry, are presented as an introduction in t...

  6. Soil Physics

    Science.gov (United States)

    Marshall, T. J.; Holmes, J. W.; Rose, C. W.

    1996-06-01

    Now in its third edition, this textbook gives a comprehensive account of soil physics with emphasis on field applications for students and research workers engaged in water resources studies, soil sciences, and plant sciences. The authors have added chapters on soil erosion, conservation, and the role of soil in affecting water quality to this new edition. The book gives an account of how water influences the structure and strength of soil; how plants absorb water from soils; how water from rain and irrigation enters the soil and flows through it to contribute to stream flow and flow in artificial drains; how soluble salts and chemical pollutants are transported; how soils are eroded by water and wind; and how the evaporation rate from the land surface is influenced by soil water supply, the nature of the plant cover and the evaporative power of the atmosphere. This book will be useful to students and research workers in environmental sciences, hydrology, agriculture, soil science, and civil engineering.

  7. Physics-10

    Science.gov (United States)

    Marinciuc, Mihai; Rusu, Spiridon

    The textbook is designated for the 10-th class of real and humanitarian lyceums, according the curriculum of the Ministry of Education of the Republic of Moldova for lyceums. It encomprises mechanics in 5 chapters (Kynematics (Trajectory, Relativity of the Motion, Circular Motion and other); Dynamics and the Forces in Nature (The mass and Force, Universal attraction, Elastic Forces, Friction, The motion of the Bodies under the action of many forces, The relativity Principle of Galilei and other); Statics; Mechanical Impuls and its conservation; Mechanical work and Mechanical Energy and its conservation( Mechanical work and Power, Kynetic Energy, The mechanical work of the Elastic Force, The conservation laws) and Molecular Physics and Thermdynamics in 5 chapters (The structure of the Matter; Gases and their properties (Simplest transformations, The molecular-kynetic theory, Real gases) ; Solids and Liquids (The Hook's law, Superficial tension, Dilatation and other); Phase transitions (including sublimation); (Calorimetry; Thermal machines; The second law of thermodynamics and other). The textbook includes also 8 laboratory (experimental) works, a number of questions for control and a number of 300 problems, half of which have answers. Short biographies of about 15 physicists are included. The textbook is illustrated with diagrames, paintings and portrets in black and white.

  8. Antineutron physics

    CERN Document Server

    Bressani, Tullio

    2003-01-01

    Antineutrons ($\\overline{n}$'s) have been used only in the last few years as projectiles for nuclear and particle physics experiments, mainly in the low momentum region. The reason is that, in spite of some undoubted advantages (absence of Coulomb corrections, pure I=1 state for the ($\\overline{n}p$) system), the difficulties in obtaining beams of $\\overline{n}$'s of suitable intensity and energy definition were overwhelming. The setting-up of suitable beams at BNL and mainly at CERN LEAR (with momentum lower than 400 MeV/c) allowed a first round of interesting experiments. In this review a summary of the most important experimental issues obtained in this field will be presented. They range from studies on the antineutron annihilation dynamics, intended to shed light on the mechanisms responsible for the particles production as well as for the possible formation of quasinuclear nucleon-antinucleon bound states, to meson spectroscopy researches, aiming to identify the existence of new, possibly exotic, resona...

  9. Diffractive Physics

    CERN Document Server

    Martin, A D; Khoze, V A; Krauss, F; Ryskin, M G; Zapp, K

    2012-01-01

    `Soft' high-energy interactions are clearly important in pp collisions. Indeed, these events are dominant by many orders of magnitude, and about 40% are of diffractive origin; that is, due to elastic scattering or proton dissociation. Moreover, soft interactions unavoidably give an underlying component to the rare `hard' events, from which we hope to extract new physics. Here, we discuss how to quantify this contamination. First we present a brief introduction to diffraction. We emphasize the different treatment required for proton dissociation into low- and high-mass systems; the former requiring a multichannel eikonal approach, and the latter the computation of triple-Pomeron diagrams with multi-Pomeron corrections. Then we give an overview of the Pomeron, and explain how the QCD (BFKL-type) Pomeron is the natural object to continue from the `hard' to the `soft' domain. In this way we can obtain a partonic description of soft interactions. We introduce the so-called KMR model, based on this partonic approac...

  10. Response Surface Modelling of Electrosprayed Polyacrylonitrile Nanoparticle Size

    OpenAIRE

    Sanaz Khademolqorani; Ali Zeinal Hamadani; Hossein Tavanai

    2014-01-01

    Electrospraying (electrohydrodynamic spraying) is a method of liquid atomization by electrical forces. Spraying solutions or suspensions allow production of fine particles, down to nanometer size. These particles are interesting for a wide variety of applications, thanks to their unprecedented chemical and physical behaviour in comparison to their bulk form. Knowledge of the particle size in powders is important in many studies employing nanoparticles. In this paper, the effect of some proces...

  11. Kinetic narrowing of size distribution

    Science.gov (United States)

    Dubrovskii, V. G.

    2016-05-01

    We present a model that reveals an interesting possibility for narrowing the size distribution of nanostructures when the deterministic growth rate changes its sign from positive to negative at a certain stationary size. Such a behavior occurs in self-catalyzed one-dimensional III-V nanowires and more generally whenever a negative "adsorption-desorption" term in the growth rate is compensated by a positive "diffusion flux." By asymptotically solving the Fokker-Planck equation, we derive an explicit representation for the size distribution that describes either Poissonian broadening or self-regulated narrowing depending on the parameters. We show how the fluctuation-induced spreading of the size distribution can be completely suppressed in systems with size self-stabilization. These results can be used for obtaining size-uniform ensembles of different nanostructures.

  12. On the Relationship between Pollen Size and Genome Size

    Directory of Open Access Journals (Sweden)

    Charles A. Knight

    2010-01-01

    Full Text Available Here we test whether genome size is a predictor of pollen size. If it were, inferences of ancient genome size would be possible using the abundant paleo-palynolgical record. We performed regression analyses across 464 species of pollen width and genome size. We found a significant positive trend. However, regression analysis using phylogentically independent contrasts did not support the correlated evolution of these traits. Instead, a large split between angiosperms and gymnosperms for both pollen width and genome size was revealed. Sister taxa were not more likely to show a positive contrast when compared to deeper nodes. However, significantly more congeneric species had a positive trend than expected by chance. These results may reflect the strong selection pressure for pollen to be small. Also, because pollen grains are not metabolically active when measured, their biology is different than other cells which have been shown to be strongly related to genome size, such as guard cells. Our findings contrast with previously published research. It was our hope that pollen size could be used as a proxy for inferring the genome size of ancient species. However, our results suggest pollen is not a good candidate for such endeavors.

  13. Physics of magnetic nanostructures

    CERN Document Server

    Owens, Frank J

    2015-01-01

    This book discusses how the important properties of materials such as the cohesive energy, and the electronic and vibrational structures are affected when materials have at least one length in the nanometer range. The author uses relatively simple models of the solid state to explain why these changes in the size and dimension in the nanometer regime occur. The text also reviews the physics of magnetism and experimental methods of measuring magnetic properties necessary to understanding how nanosizing affects magnetism. Various kinds of magnetic structures are presented by the author in order to explain how nanosizing influences their magnetic properties. The book also presents potential and actual applications of nanomaterials in the fields of medicine and computer data storage.

  14. Effective sizes for subdivided populations.

    Science.gov (United States)

    Chesser, R K; Rhodes, O E; Sugg, D W; Schnabel, A

    1993-12-01

    Many derivations of effective population sizes have been suggested in the literature; however, few account for the breeding structure and none can readily be expanded to subdivided populations. Breeding structures influence gene correlations through their effects on the number of breeding individuals of each sex, the mean number of progeny per female, and the variance in the number of progeny produced by males and females. Additionally, hierarchical structuring in a population is determined by the number of breeding groups and the migration rates of males and females among such groups. This study derives analytical solutions for effective sizes that can be applied to subdivided populations. Parameters that encapsulate breeding structure and subdivision are utilized to derive the traditional inbreeding and variance effective sizes. Also, it is shown that effective sizes can be determined for any hierarchical level of population structure for which gene correlations can accrue. Derivations of effective sizes for the accumulation of gene correlations within breeding groups (coancestral effective size) and among breeding groups (intergroup effective size) are given. The results converge to traditional, single population measures when similar assumptions are applied. In particular, inbreeding and intergroup effective sizes are shown to be special cases of the coancestral effective size, and intergroup and variance effective sizes will be equal if the population census remains constant. Instantaneous solutions for effective sizes, at any time after gene correlation begins to accrue, are given in terms of traditional F statistics or transition equations. All effective sizes are shown to converge upon a common asymptotic value when breeding tactics and migration rates are constant. The asymptotic effective size can be expressed in terms of the fixation indices and the number of breeding groups; however, the rate of approach to the asymptote is dependent upon dispersal

  15. Materialised Ideals Sizes and Beauty

    OpenAIRE

    Kirsi Laitala; Ingun Grimstad Klepp; Benedicte Hauge

    2011-01-01

    Today’s clothing industry is based on a system where clothes are made in ready-to-wear sizes and meant to fit most people. Studies have pointed out that consumers are discontent with the use of these systems: size designations are not accurate enough to find clothing that fits, and different sizes are poorly available. This article discusses in depth who these consumers are, and which consumer groups are the most dissatisfied with today’s sizing systems. Results are based on a web survey wher...

  16. Processing multidimensional nuclear physics data

    Energy Technology Data Exchange (ETDEWEB)

    Becker, J. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    Modern Ge detector arrays for gamma-ray spectroscopy are producing data sets unprecedented in size and event multiplicity. Gammasphere, the DOE sponsored array, has the following characteristics: (1) High granularity (110 detectors); (2) High efficiency (10%); and (3) Precision energy measurements (Delta EE = 0.2%). Characteristics of detector line shape, the data set, and the standard practice in the nuclear physics community to the nuclear gamma-ray cascades from the 4096 times 4096 times 4096 data cube will be discussed.

  17. Size did not matter: An evolutionary account of the variation in penis size and size anxiety

    Directory of Open Access Journals (Sweden)

    Menelaos Apostolou

    2016-12-01

    Full Text Available The human penis exhibits considerable variation in size, while a substantial proportion of the adult male population experiences size anxiety. This paper employs an evolutionary framework in order to understand this variation, as well as the concern men exhibit about the adequacy of the size of their penis. It is argued that female choice has been one important sexual selection force, responsible for shaping the size of the penis. However, this force has been relatively weak, because women do not consider the size of their partners’ penis to be the most important determinant of their sexual satisfaction. Also, in ancestral human societies, sexual satisfaction was a secondary concern, while women had limited space to exercise mate choice. The mismatch between ancestral and modern conditions, with female choice being stronger in the present than in the past, causes anxiety in men about their ability to satisfy their partners, which is also manifested in their concerns about size.

  18. Self body-size perception in an insect

    Science.gov (United States)

    Ben-Nun, Amir; Guershon, Moshe; Ayali, Amir

    2013-05-01

    Animals negotiating complex environments encounter a wide range of obstacles of different shapes and sizes. It is greatly beneficial for the animal to react to such obstacles in a precise, context-specific manner, in order to avoid harm or even simply to minimize energy expenditure. An essential key challenge is, therefore, an estimation of the animal's own physical characteristics, such as body size. A further important aspect of self body-size perception (or SBSP) is the need to update it in accordance with changes in the animal's size and proportions. Despite the major role of SBSP in functional behavior, little is known about if and how it is mediated. Here, we demonstrate that insects are also capable of self perception of body size and that this is a vital factor in allowing them to adjust their behavior following the sudden and dramatic growth associated with periodic molting. We reveal that locusts' SBSP is strongly correlated with their body size. However, we show that the dramatic change in size accompanying adult emergence is not sufficient to create a new and updated SBSP. Rather, this is created and then consolidated only following the individuals' experience and interaction with the physical environment. Behavioral or pharmacological manipulations can both result in maintenance of the old larval SBSP. Our results emphasize the importance of learning and memory-related processes in the development and update of SBSP, and highlight the advantage of insects as good models for a detailed study on the neurobiological and molecular aspects of SBSP.

  19. Particle size dependent response of aerosol counters

    Science.gov (United States)

    Ankilov, A.; Baklanov, A.; Colhoun, M.; Enderle, K.-H.; Gras, J.; Julanov, Yu.; Kaller, D.; Lindner, A.; Lushnikov, A. A.; Mavliev, R.; McGovern, F.; O'Connor, T. C.; Podzimek, J.; Preining, O.; Reischl, G. P.; Rudolf, R.; Sem, G. J.; Szymanski, W. W.; Vrtala, A. E.; Wagner, P. E.; Winklmayr, W.; Zagaynov, V.

    During an international workshop at the Institute for Experimental Physics of the University of Vienna, Austria, which was coordinated within the Committee on Nucleation and Atmospheric Aerosols (IAMAS-IUGG), 10 instruments for aerosol number concentration measurement were studied, covering a wide range of methods based on various different measuring principles. In order to investigate the detection limits of the instruments considered with respect to particle size, simultaneous number concentration measurements were performed for monodispersed aerosols with particle sizes ranging from 1.5 to 50 nm diameter and various compositions. The instruments considered show quite different response characteristics, apparently related to the different vapors used in the various counters to enlarge the particles to an optically detectable size. A strong dependence of the 50% cutoff diameter on the particle composition in correlation with the type of vapor used in the specific instrument was found. An enhanced detection efficiency for ultrafine hygroscopic sodium chloride aerosols was observed with water operated systems, an analogous trend was found for n-butanol operated systems with nonhygroscopic silver and tungsten oxide particles.

  20. Physical processing efficiency of saline vs. alkaline spent batteries

    OpenAIRE

    Cabral, Marta; Nogueira, C. A.; Margarido, F.

    2008-01-01

    Physical processing of spent batteries which includes shredding and sieving operation is the first step for chemical treatment by hydrometallurgy. A laboratory study was carried out to evaluate physical processing efficiency, by analysing the resulting particle size, of alkaline and saline mignon-type Zn-MnO2 batteries. After shredding with a tip shredder, results obtained showed that alkaline batteries were more efficiently size reduced than saline batteries. Difference in particle size dist...

  1. Food aroma affects bite size

    Directory of Open Access Journals (Sweden)

    de Wijk René A

    2012-03-01

    Full Text Available Abstract Background To evaluate the effect of food aroma on bite size, a semisolid vanilla custard dessert was delivered repeatedly into the mouth of test subjects using a pump while various concentrations of cream aroma were presented retronasally to the nose. Termination of the pump, which determined bite size, was controlled by the subject via a push button. Over 30 trials with 10 subjects, the custard was presented randomly either without an aroma, or with aromas presented below or near the detection threshold. Results Results for ten subjects (four females and six males, aged between 26 and 50 years, indicated that aroma intensity affected the size of the corresponding bite as well as that of subsequent bites. Higher aroma intensities resulted in significantly smaller sizes. Conclusions These results suggest that bite size control during eating is a highly dynamic process affected by the sensations experienced during the current and previous bites.

  2. Cell Size Regulation in Bacteria

    Science.gov (United States)

    Amir, Ariel

    2014-05-01

    Various bacteria such as the canonical gram negative Escherichia coli or the well-studied gram positive Bacillus subtilis divide symmetrically after they approximately double their volume. Their size at division is not constant, but is typically distributed over a narrow range. Here, we propose an analytically tractable model for cell size control, and calculate the cell size and interdivision time distributions, as well as the correlations between these variables. We suggest ways of extracting the model parameters from experimental data, and show that existing data for E. coli supports partial size control, and a particular explanation: a cell attempts to add a constant volume from the time of initiation of DNA replication to the next initiation event. This hypothesis accounts for the experimentally observed correlations between mother and daughter cells as well as the exponential dependence of size on growth rate.

  3. Size-dependent concentrations of thermal vacancies in solid films.

    Science.gov (United States)

    Gao, Panpan; Wu, Quan; Li, Xi; Ma, Hongxin; Zhang, Hao; Volinsky, Alex A; Qiao, Lijie; Su, Yanjing

    2016-08-10

    Solid films are considered as typical model systems to study size effects on thermal vacancy concentration in nanomaterials. By combining the generalized Young-Laplace equation with the chemical potential of vacancies, a strict size-dependent thermodynamic model of vacancies, which includes the surface intrinsic elastic parameters of the eigenstress, Young's modulus and the geometric size of the solid films, was established. The vacancy concentration changes in the film with respect to the bulk value, depending on the geometric size and surface stress sign of the solid films. Atomistic simulations of Au and Pt films verified the developed thermodynamic model. These results provide physical insights into the size-dependent thermal vacancy concentration in nanomaterials.

  4. Promoting Physical Education: The Link to Academic Achievement

    Science.gov (United States)

    Smith, Nicole J.; Lounsbery, Monica

    2009-01-01

    Quality physical education is recognized for its health-related benefits and should be supported as an integral component of every school's curriculum. Unfortunately, quality physical education is not easily established or maintained. Many physical education programs face challenges such as reduced staff, large class sizes, inadequate facilities…

  5. Materialised Ideals Sizes and Beauty

    Directory of Open Access Journals (Sweden)

    Kirsi Laitala

    2011-04-01

    Full Text Available Today’s clothing industry is based on a system where clothes are made in ready-to-wear sizes and meant to fit most people. Studies have pointed out that consumers are discontent with the use of these systems: size designations are not accurate enough to find clothing that fits, and different sizes are poorly available. This article discusses in depth who these consumers are, and which consumer groups are the most dissatisfied with today’s sizing systems. Results are based on a web survey where 2834 Nordic consumers responded, complemented with eight in-depth interviews, market analysis on clothing sizes and in-store trouser size measurements. Results indicate that higher shares of the consumers who have a body out of touch with the existing beauty ideals express discontentment with the sizing systems and the poor selection available. In particular, large women, very large men, and thin, short men are those who experience less priority in clothing stores and have more difficulties in finding clothes that fit. Consumers tend to blame themselves when the clothes do not fit their bodies, while our study points out that the industry is to blame as they do not produce clothing for all customers.

  6. Relative eye size in elasmobranchs.

    Science.gov (United States)

    Lisney, Thomas J; Collin, Shaun P

    2007-01-01

    Variation in relative eye size was investigated in a sample of 46 species of elasmobranch, 32 species of sharks and 14 species of batoids (skates and rays). To get a measure of eye size relative to body size, eye axial diameter was scaled with body mass using least-squares linear regression, using both raw species data, where species are treated as independent data points, and phylogenetically independent contrasts. Residual values calculated for each species, using the regression equations describing these scaling relationships, were then used as a measure of relative eye size. Relative and absolute eye size varies considerably in elasmobranchs, although sharks have significantly relatively larger eyes than batoids. The sharks with the relatively largest eyes are oceanic species; either pelagic sharks that move between the epipelagic (0-200 m) and 'upper' mesopelagic (200-600 m) zones, or benthic and benthopelagic species that live in the mesopelagic (200-1,000 m) and, to a lesser extent, bathypelagic (1,000-4,000 m) zones. The elasmobranchs with the relatively smallest eyes tend to be coastal, often benthic, batoids and sharks. Active benthopelagic and pelagic species, which prey on active, mobile prey also have relatively larger eyes than more sluggish, benthic elasmobranchs that feed on more sedentary prey such as benthic invertebrates. A significant positive correlation was found between absolute eye size and relative eye size, but some very large sharks, such as Carcharodon carcharias have absolutely large eyes, but have relatively small eyes in relation to body mass. PMID:17314474

  7. Nanofluidic Size-Exclusion Chromatograph

    Science.gov (United States)

    Feldman, Sabrina; Svehla, Danielle; Grunthaner, Frank; Feldman, Jason; Shakkottai, P.

    2004-01-01

    Efforts are under way to develop a nanofluidic size-exclusion chromatograph (SEC), which would be a compact, robust, lightweight instrument for separating molecules of interest according to their sizes and measuring their relative abundances in small samples. About as large as a deck of playing cards, the nanofluidic SEC would serve, in effect, as a laboratory on a chip that would perform the functions of a much larger, conventional, bench-top SEC and ancillary equipment, while consuming much less power and much smaller quantities of reagent and sample materials. Its compactness and low power demand would render it attractive for field applications in which, typically, it would be used to identify and quantitate a broad range of polar and nonpolar organic compounds in soil, ice, and water samples. Size-exclusion chromatography is a special case of high-performance liquid chromatography. In a conventional SEC, a sample plug is driven by pressure along a column packed with silica or polymer beads that contain uniform nanopores. The interstices between, and the pores in, the beads collectively constitute a size-exclusion network. Molecules follow different paths through the size-exclusion network, such that characteristic elution times can be related to sizes of molecules: basically, smaller molecules reach the downstream end of the column after the larger ones do because the smaller ones enter minor pores and stay there for a while, whereas the larger ones do not enter the pores. The volume accessible to molecules gradually diminishes as their size increases. All molecules bigger than a pore size elute together. For most substances, the elution times and sizes of molecules can be correlated directly with molecular weights. Hence, by measuring the flux of molecules arriving at the downstream end as a function of time, one can obtain a liquid mass spectrum for the molecules present in a sample over a broad range of molecular weights.

  8. Cavitation erosion size scale effects

    Science.gov (United States)

    Rao, P. V.; Buckley, D. H.

    1984-01-01

    Size scaling in cavitation erosion is a major problem confronting the design engineers of modern high speed machinery. An overview and erosion data analysis presented in this paper indicate that the size scale exponent n in the erosion rate relationship as a function of the size or diameter can vary from 1.7 to 4.9 depending on the type of device used. There is, however, a general agreement as to the values of n if the correlations are made with constant cavitation number.

  9. The distribution of bubble sizes during reionization

    Science.gov (United States)

    Lin, Yin; Oh, S. Peng; Furlanetto, Steven R.; Sutter, P. M.

    2016-09-01

    A key physical quantity during reionization is the size of H II regions. Previous studies found a characteristic bubble size which increases rapidly during reionization, with apparent agreement between simulations and analytic excursion set theory. Using four different methods, we critically examine this claim. In particular, we introduce the use of the watershed algorithm - widely used for void finding in galaxy surveys - which we show to be an unbiased method with the lowest dispersion and best performance on Monte Carlo realizations of a known bubble size probability density function (PDF). We find that a friends-of-friends algorithm declares most of the ionized volume to be occupied by a network of volume-filling regions connected by narrow tunnels. For methods tuned to detect the volume-filling regions, previous apparent agreement between simulations and theory is spurious, and due to a failure to correctly account for the window function of measurement schemes. The discrepancy is already obvious from visual inspection. Instead, H II regions in simulations are significantly larger (by factors of 10-1000 in volume) than analytic predictions. The size PDF is narrower, and evolves more slowly with time, than predicted. It becomes more sharply peaked as reionization progresses. These effects are likely caused by bubble mergers, which are inadequately modelled by analytic theory. Our results have important consequences for high-redshift 21 cm observations, the mean free path of ionizing photons, and the visibility of Lyα emitters, and point to a fundamental failure in our understanding of the characteristic scales of the reionization process.

  10. Physics through the 1990s: Nuclear physics

    International Nuclear Information System (INIS)

    This volume is the report of the Panel on Nuclear Physics of the Physics Survey Committee, established by the National Research Council in 1983. The report presents many of the major advances in nuclear physics during the past decade, sketches the impacts of nuclear physics on other sciences and on society, and describes the current frontiers of the field. It concludes with a chapter on the recommended priorities for this discipline

  11. Physics Laboratory in UEC

    Science.gov (United States)

    Takada, Tohru; Nakamura, Jin; Suzuki, Masaru

    All the first-year students in the University of Electro-Communications (UEC) take "Basic Physics I", "Basic Physics II" and "Physics Laboratory" as required subjects; Basic Physics I and Basic Physics II are calculus-based physics of mechanics, wave and oscillation, thermal physics and electromagnetics. Physics Laboratory is designed mainly aiming at learning the skill of basic experimental technique and technical writing. Although 95% students have taken physics in the senior high school, they poorly understand it by connecting with experience, and it is difficult to learn Physics Laboratory in the university. For this reason, we introduced two ICT (Information and Communication Technology) systems of Physics Laboratory to support students'learning and staff's teaching. By using quantitative data obtained from the ICT systems, we can easily check understanding of physics contents in students, and can improve physics education.

  12. Analysis of glass fibre sizing

    DEFF Research Database (Denmark)

    Petersen, Helga Nørgaard; Kusano, Yukihiro; Brøndsted, Povl;

    2014-01-01

    Glass fibre reinforced polymer composites are widely used for industrial and engineering applications which include construction, aerospace, automotive and wind energy industry. During the manufacturing glass fibres, they are surface-treated with an aqueous solution. This process and the treated...... surfaces are called sizing. The sizing influences the properties of the interface between fibres and a matrix, and subsequently affects mechanical properties of composites. In this work the sizing of commercially available glass fibres was analysed so as to study the composition and chemical structures....... Soxhlet extraction was used to extract components of the sizing from the glass fibres. The glass fibres, their extracts and coated glass plates were analysed by Thermo-Gravimetric Analysis combined with a mass spectrometer (TGA-MS), and Attenuated Total Reflectance Fourier Transform Infrared (ATR...

  13. Extremal sizes of subspace partitions

    CERN Document Server

    Heden, Olof; Nastase, Esmeralda; Sissokho, Papa

    2011-01-01

    A subspace partition $\\Pi$ of $V=V(n,q)$ is a collection of subspaces of $V$ such that each 1-dimensional subspace of $V$ is in exactly one subspace of $\\Pi$. The size of $\\Pi$ is the number of its subspaces. Let $\\sigma_q(n,t)$ denote the minimum size of a subspace partition of $V$ in which the largest subspace has dimension $t$, and let $\\rho_q(n,t)$ denote the maximum size of a subspace partition of $V$ in which the smallest subspace has dimension $t$. In this paper, we determine the values of $\\sigma_q(n,t)$ and $\\rho_q(n,t)$ for all positive integers $n$ and $t$. Furthermore, we prove that if $n\\geq 2t$, then the minimum size of a maximal partial $t$-spread in $V(n+t-1,q)$ is $\\sigma_q(n,t)$.

  14. Sibship Size and Educational Attainment

    DEFF Research Database (Denmark)

    Jæger, Mads Meier

    2009-01-01

    Studies on family background often explain the negative effect of sibship size on educational attainment by one of two theories: the Confluence Model (CM) or the Resource Dilution Hypothesis (RDH). However, as both theories - for substantively different reasons - predict that sibship size should...... have a negative effect on educational attainment most studies cannot distinguish empirically between the CM and the RDH. In this paper I use the different theoretical predictions in the CM and RDH on the role of cognitive ability as a partial or complete mediator of the effect of sibship size...... to distinguish the two theories and to identify a unique RDH effect on educational attainment. Using sibling data from the Wisconsin Longitudinal Study (WLS) and a random effect Instrumental Variable model I find that, in addition to a negative effect on cognitive ability, sibship size also has a strong negative...

  15. The size of the nucleosome

    DEFF Research Database (Denmark)

    Bohr, Jakob; Olsen, Kasper

    2011-01-01

    The structural origin of the size of the 11 nm nucleosomal disc is addressed. On the nanometer length-scale the organization of DNA as chromatin in the chromosomes involves a coiling of DNA around the histone core of the nucleosome. We suggest that the size of the nucleosome core particle...... is a necessity when allowing for transient tensile stresses during the reorganization of DNA, e.g., during the reposition, or sliding, of a nucleosome along the DNA double helix. The mathematical model we apply is based on a tubular description of double helices assuming hard walls. When the base......-pairs of the linker-DNA is included the estimate of the size of an ideal nucleosome is in close agreement with the experimental numbers. Interestingly, the size of the nucleosome is shown to be a consequence of intrinsic properties of the DNA double helix....

  16. Finite Size Corrections for Dimers

    CERN Document Server

    Nigro, Alessandro

    2012-01-01

    In this paper we derive the finite size corrections to the energy eigenvalues of the energy for 2D dimers on a square lattice. These finite size corrections, as in the case of Critical Dense Polymers, are proportional to the eigenvalues of the Local Integrals of Motion of Bazhanov Lukyanov and Zamolodchikov for central charge $c=-2$. This sheds more light on the status of the Dimer model as a conformal field theory with this value of the certral charge.

  17. Size scaling of static friction

    OpenAIRE

    Braun, O. M.; Manini, Nicola; Tosatti, Erio

    2013-01-01

    Sliding friction across a thin soft lubricant film typically occurs by stick-slip, the lubricant fully solidifying at stick, yielding and flowing at slip. The static friction force per unit area preceding slip is known from molecular dynamics (MD) simulations to decrease with increasing contact area. That makes the large-size fate of stick-slip unclear and unknown; its possible vanishing is important as it would herald smooth sliding with a dramatic drop of kinetic friction at large size. Her...

  18. Physical Therapy (For Parents)

    Science.gov (United States)

    ... Story" 5 Things to Know About Zika & Pregnancy Physical Therapy KidsHealth > For Parents > Physical Therapy Print A A ... Finding a Physical Therapist en español Terapia física Physical Therapy Basics Doctors often recommend physical therapy (PT) for ...

  19. B Physics (Experiment)

    OpenAIRE

    Kreps, Michal

    2010-01-01

    In past few years the flavor physics made important transition from the work on confirmation the standard model of particle physics to the phase of search for effects of a new physics beyond standard model. In this paper we review current state of the physics of b-hadrons with emphasis on results with a sensitivity to new physics.

  20. PESCADOR, a web-based tool to assist text-mining of biointeractions extracted from PubMed queries

    Directory of Open Access Journals (Sweden)

    Barbosa-Silva Adriano

    2011-11-01

    Full Text Available Abstract Background Biological function is greatly dependent on the interactions of proteins with other proteins and genes. Abstracts from the biomedical literature stored in the NCBI's PubMed database can be used for the derivation of interactions between genes and proteins by identifying the co-occurrences of their terms. Often, the amount of interactions obtained through such an approach is large and may mix processes occurring in different contexts. Current tools do not allow studying these data with a focus on concepts of relevance to a user, for example, interactions related to a disease or to a biological mechanism such as protein aggregation. Results To help the concept-oriented exploration of such data we developed PESCADOR, a web tool that extracts a network of interactions from a set of PubMed abstracts given by a user, and allows filtering the interaction network according to user-defined concepts. We illustrate its use in exploring protein aggregation in neurodegenerative disease and in the expansion of pathways associated to colon cancer. Conclusions PESCADOR is a platform independent web resource available at: http://cbdm.mdc-berlin.de/tools/pescador/

  1. Environmental influences on the evolution of body size in Ammonoids

    Science.gov (United States)

    Hines, S.; Khong, C.; Pelagio, M.; Seixas, G.; Payne, J.

    2012-12-01

    A major debate in evolutionary biology and paleobiology focuses on the relative importance of ecological interactions between species versus changes in the physical environment in governing large-scale evolutionary patterns. Body size is among the most important traits of any organism, and so identifying the factors that influence size evolution can shed light on both the causes and consequences of many major evolutionary trends. However, the extent to which body size evolution over time can be explained by changes in the physical versus ecological context remains unknown. In this study, we examined body size evolution in ammonoids, an extinct group of marine cephalopods. We collected a representative body size for each genus from illustrated specimens in the Treatise on Invertebrate Paleontology. We then examined relative statistical support for six models of size evolution: random walk, directional trend, stasis, and environmental control by oxygen availability, temperature, and global sea level. No model is unambiguously supported over all others. Unbiased random walk was the best supported model (34%) and environmental control by atmospheric pO2 was the second best supported model (22%). Stasis received the least support (extinction events.

  2. Metabolic 'engines' of flight drive genome size reduction in birds.

    Science.gov (United States)

    Wright, Natalie A; Gregory, T Ryan; Witt, Christopher C

    2014-03-22

    The tendency for flying organisms to possess small genomes has been interpreted as evidence of natural selection acting on the physical size of the genome. Nonetheless, the flight-genome link and its mechanistic basis have yet to be well established by comparative studies within a volant clade. Is there a particular functional aspect of flight such as brisk metabolism, lift production or maneuverability that impinges on the physical genome? We measured genome sizes, wing dimensions and heart, flight muscle and body masses from a phylogenetically diverse set of bird species. In phylogenetically controlled analyses, we found that genome size was negatively correlated with relative flight muscle size and heart index (i.e. ratio of heart to body mass), but positively correlated with body mass and wing loading. The proportional masses of the flight muscles and heart were the most important parameters explaining variation in genome size in multivariate models. Hence, the metabolic intensity of powered flight appears to have driven genome size reduction in birds.

  3. Psychosocial factors underlying physical activity

    Directory of Open Access Journals (Sweden)

    Ji Cheng-Ye

    2007-09-01

    of physical activity on academic achievement and other factors beyond physical health; barriers of not having enough time and having too many assignments perceived to hinder frequent physical activity; and parental approval. More rigorous research on psychosocial determinants with close-ended items developed from these open-ended data and with larger sample sizes of students is necessary. Research with parents and school staff will be needed to understand the perceptions of these stakeholder groups key to creating the students' social environment.

  4. Size-assortative mating and sexual size dimorphism are predictable from simple mechanics of mate-grasping behavior

    Directory of Open Access Journals (Sweden)

    Jablonski Piotr G

    2010-11-01

    Full Text Available Abstract Background A major challenge in evolutionary biology is to understand the typically complex interactions between diverse counter-balancing factors of Darwinian selection for size assortative mating and sexual size dimorphism. It appears that rarely a simple mechanism could provide a major explanation of these phenomena. Mechanics of behaviors can predict animal morphology, such like adaptations to locomotion in animals from various of taxa, but its potential to predict size-assortative mating and its evolutionary consequences has been less explored. Mate-grasping by males, using specialized adaptive morphologies of their forelegs, midlegs or even antennae wrapped around female body at specific locations, is a general mating strategy of many animals, but the contribution of the mechanics of this wide-spread behavior to the evolution of mating behavior and sexual size dimorphism has been largely ignored. Results Here, we explore the consequences of a simple, and previously ignored, fact that in a grasping posture the position of the male's grasping appendages relative to the female's body is often a function of body size difference between the sexes. Using an approach taken from robot mechanics we model coercive grasping of females by water strider Gerris gracilicornis males during mating initiation struggles. We determine that the male optimal size (relative to the female size, which gives the males the highest grasping force, properly predicts the experimentally measured highest mating success. Through field sampling and simulation modeling of a natural population we determine that the simple mechanical model, which ignores most of the other hypothetical counter-balancing selection pressures on body size, is sufficient to account for size-assortative mating pattern as well as species-specific sexual dimorphism in body size of G. gracilicornis. Conclusion The results indicate how a simple and previously overlooked physical mechanism

  5. New Physics Search in Flavour Physics

    Energy Technology Data Exchange (ETDEWEB)

    Hurth, Tobias; /CERN /SLAC

    2006-01-04

    With the running B, kaon and neutrino physics experiments, flavour physics takes centre stage within today's particle physics. We discuss the opportunities offered by these experiments in our search for new physics beyond the SM and discuss their complementarity to collider physics. We focus on rare B and kaon decays, highlighting specific observables in an exemplary mode. We also comment on the so-called B {yields} {pi}{pi} and B {yields} K{pi} puzzles. Moreover, we briefly discuss the restrictive role of long-distance strong interactions and some new tools such as QCD factorization and SCET to handle them.

  6. Experimental determination of size distributions: analyzing proper sample sizes

    Science.gov (United States)

    Buffo, A.; Alopaeus, V.

    2016-04-01

    The measurement of various particle size distributions is a crucial aspect for many applications in the process industry. Size distribution is often related to the final product quality, as in crystallization or polymerization. In other cases it is related to the correct evaluation of heat and mass transfer, as well as reaction rates, depending on the interfacial area between the different phases or to the assessment of yield stresses of polycrystalline metals/alloys samples. The experimental determination of such distributions often involves laborious sampling procedures and the statistical significance of the outcome is rarely investigated. In this work, we propose a novel rigorous tool, based on inferential statistics, to determine the number of samples needed to obtain reliable measurements of size distribution, according to specific requirements defined a priori. Such methodology can be adopted regardless of the measurement technique used.

  7. Vol. 2: Nuclear Physics

    International Nuclear Information System (INIS)

    Problems of modern physics and the situation with physical research in Ukraine are considered. Programme of the conference includes scientific and general problems. Its proceedings are published in 6 volumes. The papers presented in this volume refer to nuclear physics

  8. Quantum Physics for Beginners.

    Science.gov (United States)

    Strand, J.

    1981-01-01

    Suggests a new approach for teaching secondary school quantum physics. Reviews traditional approaches and presents some characteristics of the three-part "Quantum Physics for Beginners" project, including: quantum physics, quantum mechanics, and a short historical survey. (SK)

  9. Vol. 6: Plasma Physics

    International Nuclear Information System (INIS)

    Problems of modern physics and the situation with physical research in Ukraine are considered. Programme of the conference includes scientific and general problems. Its proceeding are published in 6 volumes. The papers presented in this volume refer to plasma physics

  10. Theoretical physics division

    International Nuclear Information System (INIS)

    The studies in 1977 are reviewed. In theoretical nuclear physics: nuclear structure, nuclear reactions, intermediate energy physics; in elementary particle physics: field theory, strong interactions dynamics, nucleon-nucleon interactions, new particles, current algebra, symmetries and quarks are studied

  11. Guide to Physical Activity

    Science.gov (United States)

    ... Families ( We Can! ) Health Professional Resources Guide to Physical Activity Physical activity is an important part of your ... to injury. Examples of moderate-intensity amounts of physical activity Common Chores Washing and waxing a car for ...

  12. Physical Activity Assessment

    Science.gov (United States)

    Current evidence convincingly indicates that physical activity reduces the risk of colon and breast cancer. Physical activity may also reduce risk of prostate cancer. Scientists are also evaluating potential relationships between physical activity and other cancers.

  13. Physical properties and fisheries

    Digital Repository Service at National Institute of Oceanography (India)

    Antony, M.K.

    The physical aspects influencing the different stages of behaviour of the marine fish can be divided into two categories (1) the physical properties of the ocean like temperature, salinity, oxygen, high penetration etc.; and (2) the physical...

  14. Inverse size scaling of the nucleolus by a concentration-dependent phase transition.

    Science.gov (United States)

    Weber, Stephanie C; Brangwynne, Clifford P

    2015-03-01

    Just as organ size typically increases with body size, the size of intracellular structures changes as cells grow and divide. Indeed, many organelles, such as the nucleus [1, 2], mitochondria [3], mitotic spindle [4, 5], and centrosome [6], exhibit size scaling, a phenomenon in which organelle size depends linearly on cell size. However, the mechanisms of organelle size scaling remain unclear. Here, we show that the size of the nucleolus, a membraneless organelle important for cell-size homeostasis [7], is coupled to cell size by an intracellular phase transition. We find that nucleolar size directly scales with cell size in early C. elegans embryos. Surprisingly, however, when embryo size is altered, we observe inverse scaling: nucleolar size increases in small cells and decreases in large cells. We demonstrate that this seemingly contradictory result arises from maternal loading of a fixed number rather than a fixed concentration of nucleolar components, which condense into nucleoli only above a threshold concentration. Our results suggest that the physics of phase transitions can dictate whether an organelle assembles, and, if so, its size, providing a mechanistic link between organelle assembly and cell size. Since the nucleolus is known to play a key role in cell growth, this biophysical readout of cell size could provide a novel feedback mechanism for growth control.

  15. Project X: Physics Opportunities

    CERN Document Server

    Kronfeld, Andreas S; Al-Binni, Usama; Altmannshofer, Wolfgang; Ankenbrandt, Charles; Babu, Kaladi; Banerjee, Sunanda; Bass, Matthew; Batell, Brian; Baxter, David V; Berezhiani, Zurab; Bergevin, Marc; Bernstein, Robert; Bhattacharya, Sudeb; Bishai, Mary; Blum, Thomas; Bogacz, S Alex; Brice, Stephen J; Brod, Joachim; Bross, Alan; Buchoff, Michael; Burgess, Thomas W; Carena, Marcela; Castellanos, Luis A; Chattopadhyay, Subhasis; Chen, Mu-Chun; Cherdack, Daniel; Christ, Norman H; Chupp, Tim; Cirigliano, Vincenzo; Coloma, Pilar; Coppola, Christopher E; Cowsik, Ramanath; Crabtree, J Allen; Delahaye, Jean-Pierre; Denisov, Dmitri; deNiverville, Patrick; de Gouvêa, André; Dharmapalan, Ranjan; Dolgov, Alexander; Dvali, Georgi; Eichten, Estia; Engelfried, Jürgen; Ferguson, Phillip D; Gabriel, Tony; Gal, Avraham; Gallmeier, Franz; Ganezer, Kenneth S; Gardner, Susan; Glenzinski, Douglas; Godfrey, Stephen; Golubeva, Elena S; Gori, Stefania; Graves, Van B; Greene, Geoffrey; Griffard, Cory L; Haisch, Ulrich; Handler, Thomas; Hartfiel, Brandon; Hawari, Ayman; Heilbronn, Lawrence; Hill, James E; Huber, Patrick; Jaffe, David E; Johnson, Christian; Kamyshkov, Yuri; Kaplan, Daniel M; Kerbikov, Boris; Kiburg, Brendan; Kirk, Harold G; Klein, Andreas; Knoepfel, Kyle; Kopeliovich, Boris; Kopeliovich, Vladimir; Kopp, Joachim; Korsch, Wolfgang; Kribs, Graham; Lipton, Ronald; Liu, Chen-Yu; Lorenzon, Wolfgang; Lu, Zheng-Tian; Makins, Naomi C R; McKeen, David; Mills, Geoffrey; Mohapatra, Rabindra; Mokhov, Nikolai V; Mocko, Michael; Muhrer, Guenter; Mumm, Pieter; Okun, Lev; Neuffer, David; Palmer, Mark A; Palmer, Robert; Pattie, Robert W; Phillips, David G; Pronsikh, Vitaly; Pitts, Kevin; Pospelov, Maxim; Quigg, Chris; Ramberg, Erik; Ray, Amlan; Reimer, Paul E; Richards, David G; Ritz, Adam; Roy, Amit; Ruggles, Arthur; Ryne, Robert; Sarkar, Utpal; Saunders, Andy; Semertzidis, Yannis K; Serebrov, Anatoly; Shimizu, Hirohiko; Shrock, Robert; Snopok, Pavel V; Snow, William M; Sikdar, Arindam K; Soha, Aria; Spanier, Stefan; Striganov, Sergei; Tang, Zhaowen; Townsend, Lawrence; Urheim, Jon; Vainshtein, Arkady; Van Kooten, Richard J; Van de Water, Richard; Van de Water, Ruth S; Wehring, Bernard; Whitehead, Lisa; Wilson, Robert J; Worcester, Elizabeth; Young, Albert R; Wester, William C; Zeller, Geralyn

    2013-01-01

    Part 2 of "Project X: Accelerator Reference Design, Physics Opportunities, Broader Impacts". In this Part, we outline the particle-physics program that can be achieved with Project X, a staged superconducting linac for intensity-frontier particle physics. Topics include neutrino physics, kaon physics, muon physics, electric dipole moments, neutron-antineutron oscillations, new light particles, hadron structure, hadron spectroscopy, and lattice-QCD calculations.

  16. Digital grain-size analysis based on autocorrelation algorithm

    Science.gov (United States)

    Cheng, Zhixuan; Liu, Haijiang

    2015-08-01

    Grain size is one of the most important parameters in geology and coastal engineering. However, all traditional methods are time consuming, laborious, and expensive. In this study, the autocorrelation technique, which was first expounded by Rubin (2004), was extended to estimate the size of well-sorted sediments and the grain-size distribution of mixed-size sediments. Long and intermediate axes of well-sorted sediments ranging from 1 to 20 mm obtained from applying the autocorrelation method are compared with the corresponding results measured using a vernier caliper. Using the autocorrelation technique, the sediment mean size was calculated and was found to compare better with point counts than sieving. Regarding the mixed-size sediment, a nonlinear programming method, which is different from the conventional 'least-squares with non-negativity' method, the kernel density method, and the maximum entropy method, was used to obtain the representative grain sizes and associated sediment inherent parameters, such as mean diameter, median diameter, sorting, skewness, and kurtosis. Image pre-processing was used in the present analysis to enhance the contrast of the recorded image, and a conversion method applied to take into account the difference between the two-dimensional digital image method and the three-dimensional sieving method. Using the modified fitting points and the improved Gaussian function fitting method, the cumulative grain-size distribution curve and the probability density curve of the mixed-size sediments were obtained. The enhanced autocorrelation technique that was developed from the traditional 'look-up-catalogue' approach provided a more accurate estimation of the grain-size distribution, as well as the relevant physical parameters of the mixed-size sediment.

  17. Origin of size effect on efficiency of organic photovoltaics

    DEFF Research Database (Denmark)

    Manor, Assaf; Katz, Eugene A.; Tromholt, Thomas;

    2011-01-01

    on the voltage dependence of photocurrent and dark current is the key to understanding size limitation of the organic photovoltaics (OPV) efficiency. Practical methods to overcome this limitation as well as the possibility of producing concentrator OPV cells operating under sunlight concentrations higher than 10......It is widely accepted that efficiency of organic solar cells could be limited by their size. However, the published data on this effect are very limited and none of them includes analysis of light intensity dependence of the key cell parameters. We report such analysis for bulk heterojunction solar...... cells of various sizes and suggest that the origin of both the size and the light intensity effects should include underlying physical mechanisms other than conventional series resistance dissipation. In particular, we conclude that the distributed nature of the ITO resistance and its influence...

  18. RNA Control of HIV-1 Particle Size Polydispersity

    CERN Document Server

    Faivre-Moskalenko, Cendrine; Thomas, Audrey; Tartour, Kevin; Beck, Yvonne; Iazykov, Maksym; Danial, John; Lourdin, Morgane; Muriaux, Delphine; Castelnovo, Martin

    2014-01-01

    HIV-1, an enveloped RNA virus, produces viral particles that are known to be much more heterogeneous in size than is typical of non-enveloped viruses. We present here a novel strategy to study HIV-1 Viral Like Particles (VLP) assembly by measuring the size distribution of these purified VLPs and subsequent viral cores thanks to Atomic Force Microscopy imaging and statistical analysis. This strategy allowed us to identify whether the presence of viral RNA acts as a modulator for VLPs and cores size heterogeneity in a large population of particles. These results are analyzed in the light of a recently proposed statistical physics model for the self-assembly process. In particular, our results reveal that the modulation of size distribution by the presence of viral RNA is qualitatively reproduced, suggesting therefore an entropic origin for the modulation of RNA uptake by the nascent VLP.

  19. Model catalysis by size-selected cluster deposition

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Scott [Univ. of Utah, Salt Lake City, UT (United States)

    2015-11-20

    This report summarizes the accomplishments during the last four years of the subject grant. Results are presented for experiments in which size-selected model catalysts were studied under surface science and aqueous electrochemical conditions. Strong effects of cluster size were found, and by correlating the size effects with size-dependent physical properties of the samples measured by surface science methods, it was possible to deduce mechanistic insights, such as the factors that control the rate-limiting step in the reactions. Results are presented for CO oxidation, CO binding energetics and geometries, and electronic effects under surface science conditions, and for the electrochemical oxygen reduction reaction, ethanol oxidation reaction, and for oxidation of carbon by water.

  20. Response Surface Modelling of Electrosprayed Polyacrylonitrile Nanoparticle Size

    Directory of Open Access Journals (Sweden)

    Sanaz Khademolqorani

    2014-01-01

    Full Text Available Electrospraying (electrohydrodynamic spraying is a method of liquid atomization by electrical forces. Spraying solutions or suspensions allow production of fine particles, down to nanometer size. These particles are interesting for a wide variety of applications, thanks to their unprecedented chemical and physical behaviour in comparison to their bulk form. Knowledge of the particle size in powders is important in many studies employing nanoparticles. In this paper, the effect of some process parameters on the size of electrosprayed polyacrylonitrile particles is presented in the form of response surface model. The model is achieved by employing a factorial design to evaluate the influence of parameters on the polyacrylonitrile nanoparticle size and response surface methodology. Four electrospraying parameters, namely, applied voltage, electrospraying solution concentration, flow rate, and syringe needle diameter were considered.

  1. Particle size and shape distributions of hammer milled pine

    Energy Technology Data Exchange (ETDEWEB)

    Westover, Tyler Lott [Idaho National Lab. (INL), Idaho Falls, ID (United States); Matthews, Austin Colter [Idaho National Lab. (INL), Idaho Falls, ID (United States); Williams, Christopher Luke [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ryan, John Chadron Benjamin [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-04-01

    Particle size and shape distributions impact particle heating rates and diffusion of volatized gases out of particles during fast pyrolysis conversion, and consequently must be modeled accurately in order for computational pyrolysis models to produce reliable results for bulk solid materials. For this milestone, lodge pole pine chips were ground using a Thomas-Wiley #4 mill using two screen sizes in order to produce two representative materials that are suitable for fast pyrolysis. For the first material, a 6 mm screen was employed in the mill and for the second material, a 3 mm screen was employed in the mill. Both materials were subjected to RoTap sieve analysis, and the distributions of the particle sizes and shapes were determined using digital image analysis. The results of the physical analysis will be fed into computational pyrolysis simulations to create models of materials with realistic particle size and shape distributions. This milestone was met on schedule.

  2. Finite size effects in the dynamics of opinion formation

    CERN Document Server

    Toral, R; Tessone, Claudio J.; Toral, Raul

    2006-01-01

    For some models of relevance in the social sciences we review some examples in which system size plays an important role in the final outcome of the dynamics. We discuss the conditions under which changes of behavior can appear only when the number of agents in the model takes a finite value. Those changes of behavior can be related to the apparent phase transitions that appear in some physical models. We show examples in the Galam's model of opinion transmission and the Axelrod's model of culture formation stressing the role that the network of interactions has on the main results of both models. Finally, we present the phenomenon of system-size stochastic resonance by which a forcing signal (identified as an advertising agent) is optimally amplified by a population of the right (intermediate) size. Our work stresses the role that the system size has in the dynamics of social systems and the inappropriateness of taking the thermodynamic limit for these systems.

  3. Optimizing Chemical Sensor Array Sizes

    International Nuclear Information System (INIS)

    Optimal selection of array sensors for a chemical sensing application is a nontrivial task. It is commonly believed that ''more is better'' when choosing the number of sensors required to achieve good chemical selectivity. However, cost and system complexity issues point towards the choice of small arrays. A quantitative array optimization is carried out to explore the selectivity of arrays of partially-selective chemical sensors as a function of array size. It is shown that modest numbers (dozens) of target analytes are completely distinguished with a range of arrays sizes. However, the array selectivity and the robustness against sensor sensitivity variability are significantly degraded if the array size is increased above a certain number of sensors, so that relatively small arrays provide the best performance. The results also suggest that data analyses for very large arrays of partially-selective sensors will be optimized by separately anal yzing small sensor subsets

  4. Entropy and Size in HIC

    CERN Document Server

    Barrañon, A; Roa, J E

    2005-01-01

    Distinct entropy definitions have been used to obtain an inverse correlation between the residual size and entropy for Heavy Ion Collisions. This explains the existence of several temperatures for different residual size bins, as reported elsewhere (Natowitz et. al., 2002). HIC collisions were simulated using binary interaction LATINO model where Pandharipande potential replicates internucleonic interaction. System temperature is defined as the temperature obtained when Kinetic Gas Theory is applied to the nucleons in the participant region. Fragments are detected with an Early Cluster Recognition Algorithm that optimizes the partitions in energy space.

  5. Size effects in crystal plasticity

    DEFF Research Database (Denmark)

    Borg, Ulrik

    2007-01-01

    of plastic flow in a single crystal, grain boundary effects in a bicrystal, and grain size effects in a polycrystal are studied. Single crystals containing micro-scale voids have also been analyzed at different loading conditions with focus on the stress and deformation fields around the voids, on void......Numerical analyses of plasticity size effects have been carried out for different problems using a developed strain gradient crystal plasticiy theory. The theory employs higher order stresses as work conjugates to slip gradients and uses higher order boundary conditions. Problems on localization...

  6. Credit rationing and firm size

    Directory of Open Access Journals (Sweden)

    G. CALCAGNINI

    2013-10-01

    Full Text Available This paper examines the likelihood of credit rationing faced by firms of different size. Contrary to common thought, several recent contributions on this topic argue that, when rationing credit, size alone is not a sufficient condition for discriminating between firms. We show that this result can be predicted using a framework based on the Stiglitz-Weiss model. In particular, in an environment of asymmetric information, we highlight how the likelihood of credit rationing depends upon the shape of the distribution function of project returns, especially its asymmetry and Kurtosis. Our empirical results do not support the hypothesis that small firms face more credit rationing than larger firms.

  7. PENGARUH UKURAN PARTIKEL DAN PROPORSI GULURONAT/MANURONAT DALAM ALGINAT TERHADAP SIFAT DAN SENSORIS PRODUK HASIL RESTRUKTURISASI DARI BUAH SIRSAK [The Influence of Particle size and Guluronic/Mannuronic Proportion of Alginate on Physical and Sensory Characteristics of Restructured Products from Soursop

    OpenAIRE

    Sri Raharjo2); Zaki Utama

    2003-01-01

    The application of restructuring technology is intended to add value for local fruits. Fresh and ripe sour sop fruits are frequently of having defective appearance, irregular shape and size, or showing signs of insect infestation which make the whole fruit is less acceptable by consumers. Previous study has indicated that sour sop fruit can be restructured into a fresh fruit product with acceptable sensory characteristics using calcium alginate gel system. This particular study was intended t...

  8. TAXONOMIES OF PHYSICS PROBLEMS IN PHYSICS EDUCATION

    Directory of Open Access Journals (Sweden)

    Monika Hanáková

    2016-09-01

    Full Text Available Taxonomies of physics problems serve as useful tools to define and analyze the requirements of pupils and students in solving physics problems and tasks. The connection between taxonomies of educational objectives is important, and these were considered in selecting taxonomies of physics problems. Different approaches to classification are briefly described in this article, as well as the importance of a balance of physics problems in instruction, according to the selected taxonomy. Two taxonomies of physics problems were chosen according to our criteria and then analyzed and described in detail. A strength, weakness, opportunity, and threat SWOT analysis was performed on the tools as well as an example of the use of the tools on a particular physics problem.

  9. PREFACE: 15th Russian Youth Conference on Physics and Astronomy (PhysicA.SPb)

    Science.gov (United States)

    Sokolovskii, Grigorii; Averkiev, Nikita

    2013-08-01

    The fifteenth Russian Youth Conference on Physics and Astronomy PhysicA.SPb was held 23-24 October 2012 in Saint-Petersburg, Russia. The Conference continues the tradition of Saint-Petersburg Seminars on Physics and Astronomy originating from the mid-90s. The main feature of PhysicA.SPb since then, remains the combination of both scientific and educational quality of the contributions delivered to the young audience. This feature makes it possible to combine the whole spectrum of modern Physics and Astronomy within one conference. PhysicA.SPb 2012 has brought together more than 150 students, young scientists and their professors from many universities and research institutes across Russia, as well as from Belarus, Ukraine, Finland, France and the United Kingdom. Oral and poster presentations were combined into a few well-defined sections among which one should name Astronomy and Astrophysics, Physics of semiconductors, Physics of solid state, Physics and technology of the alternative energetics, Nanostructured and thin-film materials, THz and UHF materials and devices, and Physics of the quantum-sized structures. This issue of the Journal of Physics: Conference Series presents the extended contributions from participants of PhysicA.SPb 2012 that were peer-reviewed by expert referees through processes administered by the Presiders of the Organising and Programme Committees to the best professional and scientific standards. Grigorii S. Sokolovskii and Nikita S. Averkiev Editors

  10. PREFACE: 16th Russian Youth Conference on Physics and Astronomy (PhysicA.SPb/2013)

    Science.gov (United States)

    2014-12-01

    The sixteenth Russian Conference on Physics and Astronomy PhysicA.SPb was held 23-24 October 2013 in Saint-Petersburg, Russia. The Conference continues the tradition of Saint-Petersburg Seminars on Physics and Astronomy originating from mid-90s. Since then PhysicA.SPb maintains both scientific and educational quality of contributions delivered to the young audience. This is the main feature of the Conference that makes it possible to combine the whole spectrum of modern Physics and Astronomy within one event. PhysicA.SPb/2013 has brought together about 200 students, young scientists and their colleague professors from many universities and research institutes across whole Russia as well as from Belarus, Ukraine, Switzerland, Turkey, Finland and France. Oral and poster presentations were combined into a few well-defined sections among which one should name Astronomy and Astrophysics, Plasma physics, hydro- and aero-dynamics, Physics of quantum-sized structures, Nanostructured and thin-film materials, Biophysics, THz and UHF materials and devices, Optoelectronic devices, Optics and spectroscopy, Atomic and elementary particles physics, Defects and impurities in solid state, Physics and technology of the alternative energetics. This issue of the Journal of Physics: Conference Series presents the extended contributions from participants of PhysicA.SPb/2013 that were peer-reviewed by expert referees through processes administered by the Presiders of the Organising and Programme Committees to the best professional and scientific standards. The Editors: Nikita S. Averkiev, Sergey A. Poniaev and Grigorii S. Sokolovskii

  11. Neutrino physics with JUNO

    Science.gov (United States)

    An, Fengpeng; An, Guangpeng; An, Qi; Antonelli, Vito; Baussan, Eric; Beacom, John; Bezrukov, Leonid; Blyth, Simon; Brugnera, Riccardo; Buizza Avanzini, Margherita; Busto, Jose; Cabrera, Anatael; Cai, Hao; Cai, Xiao; Cammi, Antonio; Cao, Guofu; Cao, Jun; Chang, Yun; Chen, Shaomin; Chen, Shenjian; Chen, Yixue; Chiesa, Davide; Clemenza, Massimiliano; Clerbaux, Barbara; Conrad, Janet; D'Angelo, Davide; De Kerret, Hervé; Deng, Zhi; Deng, Ziyan; Ding, Yayun; Djurcic, Zelimir; Dornic, Damien; Dracos, Marcos; Drapier, Olivier; Dusini, Stefano; Dye, Stephen; Enqvist, Timo; Fan, Donghua; Fang, Jian; Favart, Laurent; Ford, Richard; Göger-Neff, Marianne; Gan, Haonan; Garfagnini, Alberto; Giammarchi, Marco; Gonchar, Maxim; Gong, Guanghua; Gong, Hui; Gonin, Michel; Grassi, Marco; Grewing, Christian; Guan, Mengyun; Guarino, Vic; Guo, Gang; Guo, Wanlei; Guo, Xin-Heng; Hagner, Caren; Han, Ran; He, Miao; Heng, Yuekun; Hsiung, Yee; Hu, Jun; Hu, Shouyang; Hu, Tao; Huang, Hanxiong; Huang, Xingtao; Huo, Lei; Ioannisian, Ara; Jeitler, Manfred; Ji, Xiangdong; Jiang, Xiaoshan; Jollet, Cécile; Kang, Li; Karagounis, Michael; Kazarian, Narine; Krumshteyn, Zinovy; Kruth, Andre; Kuusiniemi, Pasi; Lachenmaier, Tobias; Leitner, Rupert; Li, Chao; Li, Jiaxing; Li, Weidong; Li, Weiguo; Li, Xiaomei; Li, Xiaonan; Li, Yi; Li, Yufeng; Li, Zhi-Bing; Liang, Hao; Lin, Guey-Lin; Lin, Tao; Lin, Yen-Hsun; Ling, Jiajie; Lippi, Ivano; Liu, Dawei; Liu, Hongbang; Liu, Hu; Liu, Jianglai; Liu, Jianli; Liu, Jinchang; Liu, Qian; Liu, Shubin; Liu, Shulin; Lombardi, Paolo; Long, Yongbing; Lu, Haoqi; Lu, Jiashu; Lu, Jingbin; Lu, Junguang; Lubsandorzhiev, Bayarto; Ludhova, Livia; Luo, Shu; Lyashuk, Vladimir; Möllenberg, Randolph; Ma, Xubo; Mantovani, Fabio; Mao, Yajun; Mari, Stefano M.; McDonough, William F.; Meng, Guang; Meregaglia, Anselmo; Meroni, Emanuela; Mezzetto, Mauro; Miramonti, Lino; Mueller, Thomas; Naumov, Dmitry; Oberauer, Lothar; Ochoa-Ricoux, Juan Pedro; Olshevskiy, Alexander; Ortica, Fausto; Paoloni, Alessandro; Peng, Haiping; Peng, Jen-Chieh; Previtali, Ezio; Qi, Ming; Qian, Sen; Qian, Xin; Qian, Yongzhong; Qin, Zhonghua; Raffelt, Georg; Ranucci, Gioacchino; Ricci, Barbara; Robens, Markus; Romani, Aldo; Ruan, Xiangdong; Ruan, Xichao; Salamanna, Giuseppe; Shaevitz, Mike; Sinev, Valery; Sirignano, Chiara; Sisti, Monica; Smirnov, Oleg; Soiron, Michael; Stahl, Achim; Stanco, Luca; Steinmann, Jochen; Sun, Xilei; Sun, Yongjie; Taichenachev, Dmitriy; Tang, Jian; Tkachev, Igor; Trzaska, Wladyslaw; van Waasen, Stefan; Volpe, Cristina; Vorobel, Vit; Votano, Lucia; Wang, Chung-Hsiang; Wang, Guoli; Wang, Hao; Wang, Meng; Wang, Ruiguang; Wang, Siguang; Wang, Wei; Wang, Yi; Wang, Yi; Wang, Yifang; Wang, Zhe; Wang, Zheng; Wang, Zhigang; Wang, Zhimin; Wei, Wei; Wen, Liangjian; Wiebusch, Christopher; Wonsak, Björn; Wu, Qun; Wulz, Claudia-Elisabeth; Wurm, Michael; Xi, Yufei; Xia, Dongmei; Xie, Yuguang; Xing, Zhi-zhong; Xu, Jilei; Yan, Baojun; Yang, Changgen; Yang, Chaowen; Yang, Guang; Yang, Lei; Yang, Yifan; Yao, Yu; Yegin, Ugur; Yermia, Frédéric; You, Zhengyun; Yu, Boxiang; Yu, Chunxu; Yu, Zeyuan; Zavatarelli, Sandra; Zhan, Liang; Zhang, Chao; Zhang, Hong-Hao; Zhang, Jiawen; Zhang, Jingbo; Zhang, Qingmin; Zhang, Yu-Mei; Zhang, Zhenyu; Zhao, Zhenghua; Zheng, Yangheng; Zhong, Weili; Zhou, Guorong; Zhou, Jing; Zhou, Li; Zhou, Rong; Zhou, Shun; Zhou, Wenxiong; Zhou, Xiang; Zhou, Yeling; Zhou, Yufeng; Zou, Jiaheng

    2016-03-01

    The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multi-purpose underground liquid scintillator detector, was proposed with the determination of the neutrino mass hierarchy (MH) as a primary physics goal. The excellent energy resolution and the large fiducial volume anticipated for the JUNO detector offer exciting opportunities for addressing many important topics in neutrino and astro-particle physics. In this document, we present the physics motivations and the anticipated performance of the JUNO detector for various proposed measurements. Following an introduction summarizing the current status and open issues in neutrino physics, we discuss how the detection of antineutrinos generated by a cluster of nuclear power plants allows the determination of the neutrino MH at a 3-4σ significance with six years of running of JUNO. The measurement of antineutrino spectrum with excellent energy resolution will also lead to the precise determination of the neutrino oscillation parameters {{sin}}2{θ }12, {{Δ }}{m}212, and | {{Δ }}{m}{ee}2| to an accuracy of better than 1%, which will play a crucial role in the future unitarity test of the MNSP matrix. The JUNO detector is capable of observing not only antineutrinos from the power plants, but also neutrinos/antineutrinos from terrestrial and extra-terrestrial sources, including supernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos, atmospheric neutrinos, and solar neutrinos. As a result of JUNO's large size, excellent energy resolution, and vertex reconstruction capability, interesting new data on these topics can be collected. For example, a neutrino burst from a typical core-collapse supernova at a distance of 10 kpc would lead to ˜5000 inverse-beta-decay events and ˜2000 all-flavor neutrino-proton ES events in JUNO, which are of crucial importance for understanding the mechanism of supernova explosion and for exploring novel phenomena such as collective neutrino oscillations

  12. Survey of semiconductor physics

    CERN Document Server

    Böer, Karl W

    1992-01-01

    Any book that covers a large variety of subjects and is written by one author lacks by necessity the depth provided by an expert in his or her own field of specialization. This book is no exception. It has been written with the encouragement of my students and colleagues, who felt that an extensive card file I had accumulated over the years of teaching solid state and semiconductor physics would be helpful to more than just a few of us. This file, updated from time to time, contained lecture notes and other entries that were useful in my research and permitted me to give to my students a broader spectrum of information than is available in typical textbooks. When assembling this material into a book, I divided the top­ ics into material dealing with the homogeneous semiconductor, the subject of the previously published Volume 1, and the inhomoge­ neous semiconductor, the subject of this Volume 2. In order to keep the book to a manageable size, sections of tutorial character which can be used as text for a g...

  13. Body size evolution in insular speckled rattlesnakes (Viperidae: Crotalus mitchellii.

    Directory of Open Access Journals (Sweden)

    Jesse M Meik

    Full Text Available BACKGROUND: Speckled rattlesnakes (Crotalus mitchellii inhabit multiple islands off the coast of Baja California, Mexico. Two of the 14 known insular populations have been recognized as subspecies based primarily on body size divergence from putative mainland ancestral populations; however, a survey of body size variation from other islands occupied by these snakes has not been previously reported. We examined body size variation between island and mainland speckled rattlesnakes, and the relationship between body size and various island physical variables among 12 island populations. We also examined relative head size among giant, dwarfed, and mainland speckled rattlesnakes to determine whether allometric differences conformed to predictions of gape size (and indirectly body size evolving in response to shifts in prey size. METHODOLOGY/PRINCIPAL FINDINGS: Insular speckled rattlesnakes show considerable variation in body size when compared to mainland source subspecies. In addition to previously known instances of gigantism on Angel de la Guarda and dwarfism on El Muerto, various degrees of body size decrease have occurred frequently in this taxon, with dwarfed rattlesnakes occurring mostly on small, recently isolated, land-bridge islands. Regression models using the Akaike information criterion (AIC showed that mean SVL of insular populations was most strongly correlated with island area, suggesting the influence of selection for different body size optima for islands of different size. Allometric differences in head size of giant and dwarf rattlesnakes revealed patterns consistent with shifts to larger and smaller prey, respectively. CONCLUSIONS/SIGNIFICANCE: Our data provide the first example of a clear relationship between body size and island area in a squamate reptile species; among vertebrates this pattern has been previously documented in few insular mammals. This finding suggests that selection for body size is influenced by changes in

  14. Physics and Physics Education at Clarion University

    Science.gov (United States)

    Aravind, Vasudeva

    Clarion University is located in the rolling hills of western Pennsylvania. We are a primarily undergraduate public institution serving about 6000 students. We graduate students who take different career paths, one of them being teaching physics at high schools. Since educating teachers of tomorrow requires us to introduce currently trending, research proven pedagogical methods, we incorporate several aspects of physics pedagogies such as peer instruction, flipped classroom and hands on experimentation in a studio physics lab format. In this talk, I discuss some of our projects on physics education, and seek to find potential collaborators interested in working along similar lines.

  15. Physics For All -- yes, it's real physics

    Science.gov (United States)

    Eisenkraft, Arthur

    2012-02-01

    Can ``all'' students learn ``real'' physics? We want to provide instruction to a wider segment of the population including those students who will not go into STEM (Science, Technology, Engineering, Math) careers. We also want to maintain the integrity of physics, challenge all students, and not compromise the rigor of our courses. Accomplishing this requires a research guided approach to instruction, curriculum and assessment. Physics First and Physics for All have become a success story for thousands of students in urban, suburban, and rural districts. At the same time, the International Physics Olympiad and other competitions have raised the expectation of what the most motivated students can achieve. Many physics educators are exploring ways to set higher goals for our most gifted students while also providing physics instruction to students previously excluded from our physics classes. Many of the same issues that K-12 educators are struggling with are equally important to the college community as colleges try to educate both future physicists and an educated citizenry. Great novels and symphonies are accessible to people of different backgrounds and levels of expertise. We should develop strategies that enable us to share an understanding of physics with all students because everyone deserves an opportunity to reflect on the wondrous workings of our universe.

  16. Physical electronics handbook of vacuum physics

    CERN Document Server

    Beck, A H

    2013-01-01

    Handbook of Vacuum Physics, Volume 2, Physical Electronics, discusses the fundamentals of electric discharges in gases. Electrical discharges in gases is used generically to denote the passage of electricity through a gas and implicitly embraces the wide variety of physical phenomena which accompany such a discharge of electricity. The discharge currents may be as small as 10-16A in certain ionization growth studies, or be as large as megamperes in thermonuclear and plasma physics studies. Key topics discussed include collision phenomena in gases; surface phenomena and transport of charged par

  17. Physics and theology

    Science.gov (United States)

    Polkinghorne, John

    2014-01-01

    The role of theology in relation to science is not to try to tell physics how to answer its own proper questions. We have every reason to believe that physics questions will eventually receive physics answers. However there are meaningful and necessary questions which arise from considering the results of physics but which exceed its selflimited power to address.

  18. The physics companion

    CERN Document Server

    Fischer-Cripps, Anthony C

    2014-01-01

    Updated and expanded with new topics, The Physics Companion, 2nd Edition offers a unique and educational approach to learning physics at a level suitable for first-year science students. This new edition expands the presentation to include senior topics, such as statistical mechanics, quantum physics, and nuclear physics.

  19. History of Medical Physics.

    Science.gov (United States)

    Laughlin, John S.

    1983-01-01

    Traces the development of basic radiation physics that underlies much of today's medical physics and looks separately at the historical development of two major subfields of medical physics: radiation therapy and nuclear medicine. Indicates that radiation physics has made important contributions to solving biomedical problems in medical…

  20. On the optimal sizing problem

    DEFF Research Database (Denmark)

    Vidal, Rene Victor Valqui

    1994-01-01

    The paper studies the problem of determining the number and dimensions of sizes of apparel so as to maximize profits. It develops a simple one-variable bisection search algorithm that gives the optimal solution. An example is solved interactively using a Macintosh LC and Math CAD, a mathematical...

  1. The "child size medicines" concept

    DEFF Research Database (Denmark)

    Nsabagasani, Xavier; Okeng, Jasper Ogwal; Mbonye, Anthony;

    2015-01-01

    of policy provisions for the MMCS recommendations. Results For most medicines for the selected diseases, appropriate strength for children’s age and weight was addressed especially in the EMHSLU 2012. However, policy documents neither referred to ‘child size medicines’ concept nor provided for flexible oral...

  2. Food aroma affects bite size

    NARCIS (Netherlands)

    Wijk, de R.A.; Polet, I.A.; Boek, W.; Coenraad, S.; Bult, J.H.F.

    2012-01-01

    Background
    To evaluate the effect of food aroma on bite size, a semisolid vanilla custard dessert was delivered repeatedly into the mouth of test subjects using a pump while various concentrations of cream aroma were presented retronasally to the nose. Termination of the pump, which determined b

  3. Particle sizes from sectional data

    DEFF Research Database (Denmark)

    Pawlas, Zbynek; Nyengaard, Jens Randel; Jensen, Eva Bjørn Vedel

    2009-01-01

    We propose a new statistical method for obtaining information about particle size distributions from sectional data without specific assumptions about particle shape. The method utilizes recent advances in local stereology. We show how to estimate separately from sectional data the variance due t...

  4. Genome size of Mycoplasma genitalium.

    OpenAIRE

    Su, C J; Baseman, J B

    1990-01-01

    The genome size of Mycoplasma genitalium was determined by using restriction enzymes that infrequently cut its DNA. The calculated value of 577 to 590 kilobases is one-fourth smaller than the genome of Mycoplasma pneumoniae, which is considered among the smallest genomes of self-replicating organisms.

  5. Variability in human body size

    Science.gov (United States)

    Annis, J. F.

    1978-01-01

    The range of variability found among homogeneous groups is described and illustrated. Those trends that show significantly marked differences between sexes and among a number of racial/ethnic groups are also presented. Causes of human-body size variability discussed include genetic endowment, aging, nutrition, protective garments, and occupation. The information is presented to aid design engineers of space flight hardware and equipment.

  6. Resource security impacts men's female breast size preferences.

    Directory of Open Access Journals (Sweden)

    Viren Swami

    Full Text Available It has been suggested human female breast size may act as signal of fat reserves, which in turn indicates access to resources. Based on this perspective, two studies were conducted to test the hypothesis that men experiencing relative resource insecurity should perceive larger breast size as more physically attractive than men experiencing resource security. In Study 1, 266 men from three sites in Malaysia varying in relative socioeconomic status (high to low rated a series of animated figures varying in breast size for physical attractiveness. Results showed that men from the low socioeconomic context rated larger breasts as more attractive than did men from the medium socioeconomic context, who in turn perceived larger breasts as attractive than men from a high socioeconomic context. Study 2 compared the breast size judgements of 66 hungry versus 58 satiated men within the same environmental context in Britain. Results showed that hungry men rated larger breasts as significantly more attractive than satiated men. Taken together, these studies provide evidence that resource security impacts upon men's attractiveness ratings based on women's breast size.

  7. Can blind persons accurately assess body size from the voice?

    Science.gov (United States)

    Pisanski, Katarzyna; Oleszkiewicz, Anna; Sorokowska, Agnieszka

    2016-04-01

    Vocal tract resonances provide reliable information about a speaker's body size that human listeners use for biosocial judgements as well as speech recognition. Although humans can accurately assess men's relative body size from the voice alone, how this ability is acquired remains unknown. In this study, we test the prediction that accurate voice-based size estimation is possible without prior audiovisual experience linking low frequencies to large bodies. Ninety-one healthy congenitally or early blind, late blind and sighted adults (aged 20-65) participated in the study. On the basis of vowel sounds alone, participants assessed the relative body sizes of male pairs of varying heights. Accuracy of voice-based body size assessments significantly exceeded chance and did not differ among participants who were sighted, or congenitally blind or who had lost their sight later in life. Accuracy increased significantly with relative differences in physical height between men, suggesting that both blind and sighted participants used reliable vocal cues to size (i.e. vocal tract resonances). Our findings demonstrate that prior visual experience is not necessary for accurate body size estimation. This capacity, integral to both nonverbal communication and speech perception, may be present at birth or may generalize from broader cross-modal correspondences. PMID:27095264

  8. Sizing up the Solar System

    Science.gov (United States)

    Wiebke, Heidi; Rogers, Meredith Park; Nargund-Joshi, Vanashri

    2011-01-01

    The American Association for the Advancement of Science (AAAS 1993) states that by the end of fifth grade, students should understand that a model, such as those depicting the solar system, is a smaller version of the real product, making it easier to physically work with and therefore learn from. However, for students and even adults,…

  9. Urban aerosol number size distributions

    Directory of Open Access Journals (Sweden)

    T. Hussein

    2004-01-01

    Full Text Available Aerosol number size distributions have been measured since 5 May 1997 in Helsinki, Finland. The presented aerosol data represents size distributions within the particle diameter size range 8-400nm during the period from May 1997 to March 2003. The daily, monthly and annual patterns of the aerosol particle number concentrations were investigated. The temporal variation of the particle number concentration showed close correlations with traffic activities. The highest total number concentrations were observed during workdays; especially on Fridays, and the lowest concentrations occurred during weekends; especially Sundays. Seasonally, the highest total number concentrations were observed during winter and spring and lower concentrations were observed during June and July. More than 80% of the number size distributions had three modes: nucleation mode (30nm, Aitken mode (20-100nm and accumulation mode (}$'>90nm. Less than 20% of the number size distributions had either two modes or consisted of more than three modes. Two different measurement sites were used; in the first (Siltavuori, 5.5.1997-5.3.2001, the arithmetic means of the particle number concentrations were 7000cm, 6500cm, and 1000cm respectively for nucleation, Aitken, and accumulation modes. In the second site (Kumpula, 6.3.2001-28.2.2003 they were 5500cm, 4000cm, and 1000cm. The total number concentration in nucleation and Aitken modes were usually significantly higher during workdays than during weekends. The temporal variations in the accumulation mode were less pronounced. The lower concentrations at Kumpula were mainly due to building construction and also the slight overall decreasing trend during these years. During the site changing a period of simultaneous measurements over two weeks were performed showing nice correlation at both sites.

  10. Physics Survey Overview

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-12-30

    An overview of a series of assignments of the branches of physics carried out by the Board on Physics and Astronomy of the National Research Council. It identifies further theories in physics and makes recommendations on preventive priorities. The Board on Physics and Astronomy (BPA) has conducted a new decadal survey of physics entitled ''Physics in a New Era''. The survey includes assessments of the main branches of physics as well as certain selected emerging areas. The various elements of the survey were prepared by separately-appointed National Research Council (NRC) committees. The BPA formed the Physics Survey Overview Committee (PSOVC) to complete the survey by preparing an overview of the field of physics to summarize and synthesize the results of the various assessments and to address cross-cutting issues that concern physics as a whole.

  11. Size from Specular Highlights for Analyzing Droplet Size Distributions

    Science.gov (United States)

    Jalba, Andrei C.; Westenberg, Michel A.; Grooten, Mart H. M.

    In mechanical engineering, heat-transfer models by dropwise condensation are under development. The condensation process is captured by taking many pictures, which show the formation of droplets, of which the size distribution and area coverage are of interest for model improvement. The current analysis method relies on manual measurements, which is time consuming. In this paper, we propose an approach to automatically extract the positions and radii of the droplets from an image. Our method relies on specular highlights that are visible on the surfaces of the droplets. We show that these highlights can be reliably extracted, and that they provide sufficient information to infer the droplet size. The results obtained by our method compare favorably with those obtained by laborious and careful manual measurements. The processing time per image is reduced by two orders of magnitude.

  12. Mangrove propagule size and oil contamination effects: Does size matter?

    Science.gov (United States)

    Naidoo, Gonasageran

    2016-09-15

    Three mangroves species with differential propagule size, Avicennia marina (2.5±0.3cm), Bruguiera gymnorrhiza (16±2cm) and Rhizophora mucronata (36±3cm), were subjected to oil contamination. In a series of glasshouse and field experiments, the sediment, propagules, leaves and stems were oiled and growth monitored. Oiling of the propagules, leaves, internodes or sediment reduced plant height, leaf number, leaf chlorophyll content index and induced growth abnormalities, leaf abscission and mortality, with effects being greatest in A. marina, intermediate in R. mucronata and least in B. gymnorrhiza. The results suggest that the greater susceptibility of A. marina to oil is due to early shedding of the protective pericarp and rapid root and shoot development after detachment from the parent tree and not to propagule size. After seedling emergence, micromorphological factors such as presence of trichomes, salt glands and thickness of protective barriers influence oil tolerance. PMID:27342901

  13. Applications of Hubble Volume in Atomic Physics, Nuclear Physics, Particle Physics, Quantum Physics and Cosmic Physics

    Directory of Open Access Journals (Sweden)

    U. V. S. Seshavatharam

    2013-08-01

    Full Text Available In this paper an attempt is made to emphasize the major shortcomings of standard cosmology. It can be suggested that, the current cosmological changes can be understood by studying the atom and the atomic nucleus through ground based experiments. If light is coming from the atoms of the gigantic galaxy, then redshift can be interpreted as an index of the galactic atomic ‘light emission mechanism’. In no way it seems to be connected with ‘galaxy receding’. With ‘cosmological increasing (emitted photon energy’, observed cosmic redshift can be considered as a measure of the age difference between our galaxy and any observed galaxy. If it is possible to show that, (from the observer older galaxy’s distance increases with its ‘age’, then ‘galaxy receding’ and ‘accelerating universe’ concepts can be put for a revision at fundamental level. At any given cosmic time, the product of ‘critical density’ and ‘Hubble volume’ gives a characteristic cosmic mass and it can be called as the ‘Hubble mass’. Interesting thing is that, Schwarzschild radius of the ‘Hubble mass’ again matches with the ‘Hubble length’. Most of the cosmologists believe that this is merely a coincidence. At any given cosmic time,’Hubble length’ can be considered as the gravitational or electromagnetic interaction range. If one is willing to think in this direction, by increasing the number of applications of Hubble mass and Hubble volume in other areas of fundamental physics like quantum physics, nuclear physics, atomic physics and particle physics - slowly and gradually - in a progressive way, concepts of ‘Black hole Cosmology’ can be strengthened and can also be confirmed.

  14. Advances in chemical physics

    CERN Document Server

    Prigogine, Ilya

    2009-01-01

    The Advances in Chemical Physics series provides the chemical physics and physical chemistry fields with a forum for critical, authoritative evaluations of advances in every area of the discipline. Filled with cutting-edge research reported in a cohesive manner not found elsewhere in the literature, each volume of the Advances in Chemical Physics series serves as the perfect supplement to any advanced graduate class devoted to the study of chemical physics.

  15. Quantum physics for beginners

    CERN Document Server

    Ficek, Zbigniew

    2016-01-01

    The textbook introduces students to the main ideas of quantum physics and the basic mathematical methods and techniques used in the fields of advanced quantum physics, atomic physics, laser physics, nanotechnology, quantum chemistry, and theoretical mathematics. The textbook explains how microscopic objects (particles) behave in unusual ways, giving rise to what's called quantum effects. It contains a wide range of tutorial problems from simple confidence-builders to fairly challenging exercises that provide adequate understanding of the basic concepts of quantum physics.

  16. ITER physics committee meeting

    International Nuclear Information System (INIS)

    This article presents the technical points associated with the ITER project that have been discussed at the committee meeting. The topics include: plasma diagnostics progress report; MHD disruptions and control; edge and pedestal physics; SOL and divertor physics; energetic particles, heating and steady-state operation; transport and internal barrier physics; confinement database and modeling; reports by the designated physics persons on the high-priority physics research areas

  17. Ecosystem size matters: the dimensionality of intralacustrine diversification in Icelandic stickleback is predicted by lake size.

    Science.gov (United States)

    Lucek, Kay; Kristjánsson, Bjarni K; Skúlason, Skúli; Seehausen, Ole

    2016-08-01

    Cases of evolutionary diversification can be characterized along a continuum from weak to strong genetic and phenotypic differentiation. Several factors may facilitate or constrain the differentiation process. Comparative analyses of replicates of the same taxon at different stages of differentiation can be useful to identify these factors. We estimated the number of distinct phenotypic groups in three-spine stickleback populations from nine lakes in Iceland and in one marine population. Using the inferred number of phenotypic groups in each lake, genetic divergence from the marine population, and physical lake and landscape variables, we tested whether ecosystem size, approximated by lake size and depth, or isolation from the ancestral marine gene pool predicts the occurrence and the extent of phenotypic and genetic diversification within lakes. We find intralacustrine phenotypic diversification to be the rule rather than the exception, occurring in all but the youngest lake population and being manifest in ecologically important phenotypic traits. Neutral genetic data further indicate nonrandom mating in four of nine studied lakes, and restricted gene flow between sympatric phenotypic groups in two. Although neither the phenotypic variation nor the number of intralacustrine phenotypic groups was associated with any of our environmental variables, the number of phenotypic traits that were differentiated was significantly positively related to lake size, and evidence for restricted gene flow between sympatric phenotypic groups was only found in the largest lakes where trait specific phenotypic differentiation was highest. PMID:27551381

  18. Aerosol Size Distribution in the marine regions

    Science.gov (United States)

    Markuszewski, Piotr; Petelski, Tomasz; Zielinski, Tymon; Pakszys, Paulina; Strzalkowska, Agata; Makuch, Przemyslaw; Kowalczyk, Jakub

    2014-05-01

    We would like to present the data obtained during the regular research cruises of the S/Y Oceania over a period of time between 2009 - 2012. The Baltic Sea is a very interesting polygon for aerosol measurements, however, also difficult due to the fact that mostly cases of a mixture of continental and marine aerosols are observed. It is possible to measure clear marine aerosol, but also advections of dust from southern Europe or even Africa. This variability of data allows to compare different conditions. The data is also compared with our measurements from the Arctic Seas, which have been made during the ARctic EXperiment (AREX). The Arctic Seas are very suitable for marine aerosol investigations since continental advections of aerosols are far less frequent than in other European sea regions. The aerosol size distribution was measured using the TSI Laser Aerosol Spectrometer model 3340 (99 channels, measurement range 0.09 μm to 7 μm), condensation particle counter (range 0.01 μm to 3 μm) and laser particle counter PMS CSASP-100-HV-SP (range 0.5 μm to 47 μm in 45 channels). Studies of marine aerosol production and transport are important for many Earth sciences such as cloud physics, atmospheric optics, environmental pollution studies and interaction between ocean and atmosphere. All equipment was placed on one of the masts of S/Y Oceania. Measurements using the laser aerosol spectrometer and condensation particle counter were made on one level (8 meters above sea level). Measurements with the laser particle counter were performed at five different levels above the sea level (8, 11, 14, 17 and 20 m). Based on aerosol size distribution the parameterizations with a Log-Normal and a Power-Law distributions were made. The aerosol source functions, characteristic for the region were also determined. Additionally, poor precision of the sea spray emission determination was confirmed while using only the aerosol concentration data. The emission of sea spray depends

  19. Physics through the 1990s: Nuclear physics

    Science.gov (United States)

    1986-01-01

    The volume begins with a non-mathematical introduction to nuclear physics. A description of the major advances in the field follows, with chapters on nuclear structure and dynamics, fundamental forces in the nucleus, and nuclei under extreme conditions of temperature, density, and spin. Impacts of nuclear physics on astrophysics and the scientific and societal benefits of nuclear physics are then discussed. Another section deals with scientific frontiers, describing research into the realm of the quark-gluon plasma; the changing description of nuclear matter, specifically the use of the quark model; and the implications of the standard model and grand unified theories of elementary-particle physics; and finishes with recommendations and priorities for nuclear physics research facilities, instrumentation, accelerators, theory, education, and data bases. Appended are a list of national accelerator facilities, a list of reviewers, a bibliography, and a glossary.

  20. Finite size effects in neutron star and nuclear matter simulations

    Energy Technology Data Exchange (ETDEWEB)

    Giménez Molinelli, P.A., E-mail: pagm@df.uba.ar; Dorso, C.O.

    2015-01-15

    In this work we study molecular dynamics simulations of symmetric nuclear and neutron star matter using a semi-classical nucleon interaction model. Our aim is to gain insight on the nature of the so-called “finite size effects”, unavoidable in this kind of simulations, and to understand what they actually affect. To do so, we explore different geometries for the periodic boundary conditions imposed on the simulation cell: cube, hexagonal prism and truncated octahedron. For nuclear matter simulations we show that, at sub-saturation densities and low temperatures, the solutions are non-homogeneous structures reminiscent of the “nuclear pasta” phases expected in neutron star matter simulations, but only one structure per cell and shaped by specific artificial aspects of the simulations—for the same physical conditions (i.e. number density and temperature) different cells yield different solutions. The particular shape of the solution at low enough temperature and a given density can be predicted analytically by surface minimization. We also show that even if this behavior is due to the imposition of periodic boundary conditions on finite systems, this does not mean that it vanishes for very large systems, and it is actually independent of the system size. We conclude that, for nuclear matter simulations, the cells' size sets the only characteristic length scale for the inhomogeneities, and the geometry of the periodic cell determines the shape of those inhomogeneities. To model neutron star matter we add a screened Coulomb interaction between protons, and perform simulations in the three cell geometries. Our simulations indeed produce the well known nuclear pasta, with (in most cases) several structures per cell. However, we find that for systems not too large results are affected by finite size in different ways depending on the geometry of the cell. In particular, at the same certain physical conditions and system size, the hexagonal prism yields a

  1. Random walks and cell size.

    Science.gov (United States)

    Agutter, P S; Wheatley, D N

    2000-11-01

    For many years, it has been believed that diffusion is the principle motive force for distributing molecules within the cell. Yet, our current information about the cell makes this improbable. Furthermore, the argument that limitations responsible for the relative constancy of cell size--which seldom varies by more than a factor of 2, whereas organisms can vary in mass by up to 10(24)--are based on the limits of diffusion is questionable. This essay seeks to develop an alternative explanation based on transport of molecules along structural elements in the cytoplasm and nucleus. This mechanism can better account for cell size constancy, in light of modern biological knowledge of the complex microstructure of the cell, than simple diffusion.

  2. Insert size of YAC clones - RGP physicalmap | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available [ Credits ] BLAST Search Image Search Home About Archive Update History Contact us RGP physicalma...a contents Insert size of YAC clones in the physical map Data file File name: rgp_physicalmap_insert_size.zi...p File URL: ftp://ftp.biosciencedbc.jp/archive/rgp-physicalmap/LATEST/rgp_physicalma...p_insert_size.zip File size: 3.4 KB Simple search URL http://togodb.biosciencedbc.jp/togodb/view/rgp_physicalma...ase Description Download License Update History of This Database Site Policy | Contact Us Insert size of YAC clones - RGP physicalmap | LSDB Archive ...

  3. Principles & practice of physics

    CERN Document Server

    Mazur, Eric; Dourmashkin, Peter A; Pedigo, Daryl; Bieniek, Ronald J

    2015-01-01

    Putting physics first Based on his storied research and teaching, Eric Mazur's Principles & Practice of Physics builds an understanding of physics that is both thorough and accessible. Unique organization and pedagogy allow you to develop a true conceptual understanding of physics alongside the quantitative skills needed in the course. *New learning architecture: The book is structured to help you learn physics in an organized way that encourages comprehension and reduces distraction.*Physics on a contemporary foundation: Traditional texts delay the introduction of ideas that we now see as unifying and foundational. This text builds physics on those unifying foundations, helping you to develop an understanding that is stronger, deeper, and fundamentally simpler.*Research-based instruction: This text uses a range of research-based instructional techniques to teach physics in the most effective manner possible. The result is a groundbreaking book that puts physics first, thereby making it more accessible to...

  4. Teen Sized Humanoid Robot: Archie

    Science.gov (United States)

    Baltes, Jacky; Byagowi, Ahmad; Anderson, John; Kopacek, Peter

    This paper describes our first teen sized humanoid robot Archie. This robot has been developed in conjunction with Prof. Kopacek’s lab from the Technical University of Vienna. Archie uses brushless motors and harmonic gears with a novel approach to position encoding. Based on our previous experience with small humanoid robots, we developed software to create, store, and play back motions as well as control methods which automatically balance the robot using feedback from an internal measurement unit (IMU).

  5. Effective Sizes for Subdivided Populations

    OpenAIRE

    Chesser, R. K.; Rhodes-Jr., O. E.; Sugg, D. W.; Schnabel, A.(Physikalisch Technische Bundesanstalt, Berlin, D-10587, Germany)

    1993-01-01

    Many derivations of effective population sizes have been suggested in the literature; however, few account for the breeding structure and none can readily be expanded to subdivided populations. Breeding structures influence gene correlations through their effects on the number of breeding individuals of each sex, the mean number of progeny per female, and the variance in the number of progeny produced by males and females. Additionally, hierarchical structuring in a population is determined b...

  6. Population size and environmental quality

    OpenAIRE

    Till Requate; Mark B. Cronshaw

    1997-01-01

    This paper presents a simple general equilibrium analysis of first best allocations in an economy where a consumption good is produced using labor. Production results in pollution, which is a public bad. Pollution abatement can be achieved either by restricting production or by using additional labor. We consider how the first best allocation and Pigouvian tax vary with population size. Consumers are unambiguously worse off when the population is larger, but not necessarily due to increased p...

  7. Attention modulates visual size adaptation.

    OpenAIRE

    Kreutzer, Sylvia; Fink, G R; R. Weidner

    2015-01-01

    The current study determined in healthy subjects (n = 16) whether size adaptation occurs at early, i.e., preattentive, levels of processing or whether higher cognitive processes such as attention can modulate the illusion. To investigate this issue, bottom-up stimulation was kept constant across conditions by using a single adaptation display containing both small and large adapter stimuli. Subjects' attention was directed to either the large or small adapter stimulus by means of a luminance ...

  8. Asymmetric Information and IPO Size

    OpenAIRE

    Miglo, Anton; Wu, Congsheng

    2014-01-01

    We build a model of an IPO for firms with private information about their earnings profile over time and test the model’s predictions using a complete sample of newly listed Chinese companies between 1992 and 2007. The model predicts that IPO size is positively correlated with short-term operating performance that is not directly consistent with traditional theories. It also provides an explanation for negative correlation between debt and profitability that is not consistent with standard tr...

  9. Sample Size Dependent Species Models

    OpenAIRE

    Zhou, Mingyuan; Walker, Stephen G.

    2014-01-01

    Motivated by the fundamental problem of measuring species diversity, this paper introduces the concept of a cluster structure to define an exchangeable cluster probability function that governs the joint distribution of a random count and its exchangeable random partitions. A cluster structure, naturally arising from a completely random measure mixed Poisson process, allows the probability distribution of the random partitions of a subset of a sample to be dependent on the sample size, a dist...

  10. Atmospheric cloud physics laboratory project study

    Science.gov (United States)

    Schultz, W. E.; Stephen, L. A.; Usher, L. H.

    1976-01-01

    Engineering studies were performed for the Zero-G Cloud Physics Experiment liquid cooling and air pressure control systems. A total of four concepts for the liquid cooling system was evaluated, two of which were found to closely approach the systems requirements. Thermal insulation requirements, system hardware, and control sensor locations were established. The reservoir sizes and initial temperatures were defined as well as system power requirements. In the study of the pressure control system, fluid analyses by the Atmospheric Cloud Physics Laboratory were performed to determine flow characteristics of various orifice sizes, vacuum pump adequacy, and control systems performance. System parameters predicted in these analyses as a function of time include the following for various orifice sizes: (1) chamber and vacuum pump mass flow rates, (2) the number of valve openings or closures, (3) the maximum cloud chamber pressure deviation from the allowable, and (4) cloud chamber and accumulator pressure.

  11. Tick size and stock returns

    Science.gov (United States)

    Onnela, Jukka-Pekka; Töyli, Juuso; Kaski, Kimmo

    2009-02-01

    Tick size is an important aspect of the micro-structural level organization of financial markets. It is the smallest institutionally allowed price increment, has a direct bearing on the bid-ask spread, influences the strategy of trading order placement in electronic markets, affects the price formation mechanism, and appears to be related to the long-term memory of volatility clustering. In this paper we investigate the impact of tick size on stock returns. We start with a simple simulation to demonstrate how continuous returns become distorted after confining the price to a discrete grid governed by the tick size. We then move on to a novel experimental set-up that combines decimalization pilot programs and cross-listed stocks in New York and Toronto. This allows us to observe a set of stocks traded simultaneously under two different ticks while holding all security-specific characteristics fixed. We then study the normality of the return distributions and carry out fits to the chosen distribution models. Our empirical findings are somewhat mixed and in some cases appear to challenge the simulation results.

  12. SIZE OF LIVESTOCK AGRICULTURAL OPERATIONS

    Directory of Open Access Journals (Sweden)

    Bazbanela Stere

    2015-07-01

    Full Text Available The main goal of the paper is to map the performance of Romanian farms from the perspective of livestock agricultural operations using principal component analysis technique (PCA and similarities between Romania and other countries from UE. The empirical results reveal that animal breedings farms are grouped into two categories :small and middle sized farms ; and the fact that Romania , one of Europe’s major forces in the field of livestock husbandry, has come to be one of the biggest importers of food products, although, by tradition, it is one of the continent’s countries with ideal conditions for breeding all species of animals. When clustering the countries we observ that in countries such as Greece, Italy, Portugal, Spain, cow farms, for example, do not exceed 10-16 heads and in Holland, England, Denmark, Belgium and France, the average farm size reaches 30-70 heads of milk cows. The cluster analysis revealed that in livestock operations, animal stock is the one that generates production, while the animal number indicates the size of the livestock unit.

  13. The size of the nucleosome

    CERN Document Server

    Bohr, Jakob

    2011-01-01

    The structural origin of the size of the 11 nm nucleosomal disc is addressed. On the nanometer length-scale the organization of DNA as chromatin in the chromosomes involves a coiling of DNA around the histone core of the nucleosome. We suggest that the size of the nucleosome core particle is dictated by the fulfillment of two criteria: One is optimizing the volume fraction of the DNA double helix; this requirement for close-packing has its root in optimizing atomic and molecular interactions. The other criterion being that of having a zero strain-twist coupling; being a zero-twist structure is a necessity when allowing for transient tensile stresses during the reorganization of DNA, e.g., during the reposition, or sliding, of a nucleosome along the DNA double helix. The mathematical model we apply is based on a tubular description of double helices assuming hard walls. When the base-pairs of the linker-DNA is included the estimate of the size of an ideal nucleosome is in close agreement with the experimental ...

  14. Internal Control in Swedish Small and Medium Size Enterprises

    OpenAIRE

    Gebramicheal, Zelalem Berhanu; Habtegiorgis, Tsegahiwot Teketel

    2009-01-01

    Small and medium size enterprises are currently the major part of economic activities through out the world. Nowadays, they represent about 99% of all types of enterprises in Sweden, with providing high job opportunities to its labour force as these enterprises need focus in their development; the internal control mechanism is a means and a way of directing, monitoring and measuring the SMEs resources. It plays an important role in preventing and detecting fraud and protecting the physical an...

  15. Pulsed-field electrophoresis of megabase-sized DNA.

    OpenAIRE

    Gunderson, K; Chu, G

    1991-01-01

    Success in constructing a physical map of the human genome will depend on two capabilities: rapid resolution of very large DNA and identification of migration anomalies. To address these issues, a systematic exploration of pulsed-field electrophoresis conditions for separating multimegabase-sized DNA was undertaken. Conditions were found for first liberating and then separating DNA up to 6 megabases at higher field strengths and more rapidly than previously reported. In addition, some conditi...

  16. The synthesis and applications of nano sized ceramic membranes

    International Nuclear Information System (INIS)

    Inorganic membranes composed of particles having sizes below 50 A were produced with oxides of TiO2, ZrO2, and SiO2. This presentation stresses the necessary physical chemical phenomena associated with the particle synthesis and the aggregation behavior of these particles as they are incorporated into the final membrane body. Uses of ceramic membranes in separations, ceramic membrane reactors, and the photocatalytic degradation of organic waste materials are briefly reviewed

  17. Saturated hydraulic conductivity measured on differently sized soil core samples

    OpenAIRE

    Danaa, Batjargal

    2012-01-01

    ABSTRACT This study is aiming at the estimation of different core sample size as parameter for soil physical properties and saturated hydraulic conductivity measurement. It concerns the manual reading of field experimental data collection quality at an experimental site of Czech University of Life Sciences in Prague equipped by a constant head infiltrometer. A newly constructed constant head infiltrometer of the department design was used. It consists of two Mariotte’s bottles system ...

  18. Advances in chemical physics

    CERN Document Server

    Rice, Stuart A

    2011-01-01

    The Advances in Chemical Physics series-the cutting edge of research in chemical physics The Advances in Chemical Physics series provides the chemical physics and physical chemistry fields with a forum for critical, authoritative evaluations of advances in every area of the discipline. Filled with cutting-edge research reported in a cohesive manner not found elsewhere in the literature, each volume of the Advances in Chemical Physics series offers contributions from internationally renowned chemists and serves as the perfect supplement to any advanced graduate class devoted to the study of che

  19. Advances in chemical Physics

    CERN Document Server

    Rice, Stuart A

    2011-01-01

    The Advances in Chemical Physics series-the cutting edge of research in chemical physics The Advances in Chemical Physics series provides the chemical physics and physical chemistry fields with a forum for critical, authoritative evaluations of advances in every area of the discipline. Filled with cutting-edge research reported in a cohesive manner not found elsewhere in the literature, each volume of the Advances in Chemical Physics series offers contributions from internationally renowned chemists and serves as the perfect supplement to any advanced graduate class devoted to the study of che

  20. Advances in chemical physics

    CERN Document Server

    Rice, Stuart A

    2012-01-01

    The Advances in Chemical Physics series-the cutting edge of research in chemical physics The Advances in Chemical Physics series provides the chemical physics and physical chemistry fields with a forum for critical, authoritative evaluations of advances in every area of the discipline. Filled with cutting-edge research reported in a cohesive manner not found elsewhere in the literature, each volume of the Advances in Chemical Physics series presents contributions from internationally renowned chemists and serves as the perfect supplement to any advanced graduate class devoted to the study o

  1. Advances in chemical physics

    CERN Document Server

    Rice, Stuart A

    2012-01-01

    The Advances in Chemical Physics series-the cutting edge of research in chemical physics The Advances in Chemical Physics series provides the chemical physics field with a forum for critical, authoritative evaluations of advances in every area of the discipline. Filled with cutting-edge research reported in a cohesive manner not found elsewhere in the literature, each volume of the Advances in Chemical Physics series serves as the perfect supplement to any advanced graduate class devoted to the study of chemical physics. This volume explores: Quantum Dynamical Resonances in Ch

  2. Consistency of Moderate to Vigorous Physical Activity in Middle School Physical Education.

    Science.gov (United States)

    Gill, Monique; Chan-Golston, Alec M; Rice, Lindsay N; Cole, Brian L; Koniak-Griffin, Deborah; Prelip, Michael L

    2016-01-01

    This study assessed the consistency of moderate to vigorous physical activity (MVPA) in a sample of middle school physical education lessons. Random intercept hierarchical linear regressions were employed to model the relationship between consistency of MVPA and independent variables, including lesson and teacher characteristics. Larger classes spent significantly more time in consistent MVPA in the absence of controlling for teacher characteristics. A significant interaction between class size and teacher experience suggests that experience may play a beneficial role in larger classes, and overall class size does not have to be a barrier to achieving high levels of MVPA. PMID:27536933

  3. Cooling off with physics

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, Chris [Unilever R and D (United Kingdom)

    2003-08-01

    You might think of ice cream as a delicious treat to be enjoyed on a sunny summer's day. However, to the ice-cream scientists who recently gathered in Thessaloniki in Greece for the 2nd International Ice Cream Symposium, it is a complex composite material. Ice cream consists of three dispersed phases: ice crystals, which have a mean size of 50 microns, air bubbles with a diameter of about 70 microns, and fat droplets with a size of 1 micron. These phases are held together by what is called the matrix - not a sci-fi film, but a viscous solution of sugars, milk proteins and polysaccharides. The microstructure, and hence the texture that you experience when you eat ice cream, is created in a freezing process that has remained fundamentally unchanged since the first ice-cream maker was patented in the 1840s. The ingredients - water, milk protein, fat, sugar, emulsifiers, stabilizers, flavours and a lot of air - are mixed together before being pasteurized and homogenized. They are then pumped into a cylinder that is cooled from the outside with a refrigerant. As the mixture touches the cylinder wall it freezes and forms ice crystals, which are quickly scraped off by a rotating blade. The blade is attached to a beater that disperses the ice crystals into the mixture. At the same time, air is injected and broken down into small bubbles by the shear that the beater generates. As the mixture passes along the cylinder, the number of ice crystals increases and its temperature drops. As a result, the viscosity of the mixture increases, so that more energy input is needed to rotate the beater. This energy is dissipated as heat, and when the ice cream reaches about -6 deg. C the energy input through the beater equals the energy removed as heat by the refrigerant. The process therefore becomes self-limiting and it is not possible to cool the ice cream any further. However, at -6 deg. C the microstructure is unstable. The ice cream therefore has to be removed from the freezer

  4. What enables size-selective trophy hunting of wildlife?

    Directory of Open Access Journals (Sweden)

    Chris T Darimont

    Full Text Available Although rarely considered predators, wildlife hunters can function as important ecological and evolutionary agents. In part, their influence relates to targeting of large reproductive adults within prey populations. Despite known impacts of size-selective harvests, however, we know little about what enables hunters to kill these older, rarer, and presumably more wary individuals. In other mammalian predators, predatory performance varies with knowledge and physical condition, which accumulates and declines, respectively, with age. Moreover, some species evolved camouflage as a physical trait to aid in predatory performance. In this work, we tested whether knowledge-based faculty (use of a hunting guide with accumulated experience in specific areas, physical traits (relative body mass [RBM] and camouflage clothing, and age can predict predatory performance. We measured performance as do many hunters: size of killed cervid prey, using the number of antler tines as a proxy. Examining ∼ 4300 online photographs of hunters posing with carcasses, we found that only the presence of guides increased the odds of killing larger prey. Accounting for this effect, modest evidence suggested that unguided hunters presumably handicapped with the highest RBM actually had greater odds of killing large prey. There was no association with hunter age, perhaps because of our coarse measure (presence of grey hair and the performance trade-offs between knowledge accumulation and physical deterioration with age. Despite its prevalence among sampled hunters (80%, camouflage had no influence on size of killed prey. Should these patterns be representative of other areas and prey, and our interpretations correct, evolutionarily-enlightened harvest management might benefit from regulatory scrutiny on guided hunting. More broadly, we suggest that by being nutritionally and demographically de-coupled from prey and aided by efficient killing technology and road access

  5. Increasing physical activity levels in primary school physical education: The SHARP Principles Model

    OpenAIRE

    Powell, Emma; Woodfield, Lorayne A.; Alan M Nevill

    2015-01-01

    Objectives: To evaluate the effectiveness of a one-year teaching intervention to increase moderate to vigorous physical activity (MVPA) during primary school physical education (PE). Methods: A quasi-experimental, non-equivalent group design involving four classes from two primary schools in the West Midlands, UK. In March 2014 schools were selected through purposive sampling to match schools in terms of size and demographics (baseline, n = 111: post-intervention, n = 95); data were collected...

  6. Polar cap size metrics study at CCMC

    Science.gov (United States)

    Rastaetter, L.; Kuznetsova, M. M.; Hesse, M.; Gombosi, T. I.; Raeder, J.; Weimer, D.

    2005-12-01

    The Community-Coordinated Modeling Center (CCMC) tests space physics models covering space from the Sun's corona to the Earth's ionosphere and makes them available for researchers through a run-on-request capability. The polar cap size and location as observed by global auroral imagers is used as a basis model to study the performance of global MHD simulation models and statistical models of the auroral ionosphere. With good confidence one can assume that auroral emissions are located within the closed magnetic field lines in a narrow region adjacent to the boundary of the open field line region of the polar cap. In this study we are using imager data from POLAR (FUV) for several events from 1997 to 2000 for which reasonable coverage is available. Simulation runs have been performed using the global magnetospheric models BATSRUS (T. Gombosi et al., U. Michigan) and OpenGGCM (J. Raeder, U. New Hampshire) as well as the Weimer (2000,2005) field-aligned current models (D. Weimer, Mission Research Corp.) fed with upstream solar wind data from the ACE or Geotail satellites. In addition to direct field line tracings available from the 3D MHD model outputs, we use field-aligned currents from both MHD models and the Weimer-2K model to determine the polar cap boundary by using the position of the maximum absolute FAC value in 16 local time sectors. We define skill scores that measure the agreement in the polar cap sizes and location between measurements and models as an example of implementations of metrics to track model performance and apply the analysis to a number of storm event days.

  7. Grain size effect on monotonic and cyclic deformation responses of electroformed copper with ultrafine and nano sized twins

    Science.gov (United States)

    Luo, Ji

    2007-12-01

    Refining of grain sizes is one of the most powerful tools for achieving enhanced properties and performance in polycrystalline metallic materials. It has been found that, by reducing the grain size to ultrafine and nano ranges, the strength of the materials can be significantly enhanced. However, interpretation of the influence of the grain size on the mechanical behaviour of this kind of materials is still in its infancy. Especially, as the grain size falls in these regions, conventional dislocation model is subjected to contradictory experimental results. A wide spread of the applications of these materials is hindered due to the lack of validated models. To develop the present understanding, a novel energy approach is attempted, in which deformation process was treated as an energetic process. This energy approach is experimentally tested and theoretically investigated. The experimental investigation includes mechanical response characterization and microstructure investigation. It was found that, with decreasing grain size, the static deformation mechanism appears to transform from lower hardening stage to higher stage. Similarly, the cyclic deformation mode also exhibits corresponding characteristics shifting. Such transitions are attributed to the material's internal energy increases with the decrease of the grain size, leading to the following conclusions: (1) A novel view on cyclic hardening, cyclic softening and cyclic creep in relation to the strain energy of the material is synthesized, based on which a microstructure evolution law is derived. (2) Quantitative grading of grain size is enabled for the first time. According to the presented grading method, the size of the ultrafine grain is equal to the critical grain size at which the energetic transition condition from Stage III hardening to Stage IV hardening is satisfied. (3) An original interpretation of the physical meaning for Hall-Petch constant is provided. The Hall-Petch slope constant is found

  8. The materials physics companion

    CERN Document Server

    Fischer-Cripps, Anthony C

    2014-01-01

    Introduction to Materials Physics: Structure of matter. Solid state physics. Dynamic properties of solids. Dielectric Properties of Materials: Dielectric properties. Ferroelectric and piezoelectric materials. Dielectric breakdown. Applications of dielectrics. Magnetic Properties of Materials: Magnetic properties. Magnetic moment. Spontaneous magnetization. Superconductivity.

  9. Physics and Consciousness

    OpenAIRE

    Perez, Patricio

    1995-01-01

    Some contributions of physics towards the understanding of consciousness are described. As recent relevant models, associative memory neural networks are mentioned. It is shown that consciousness and quantum physics share some properties. Two existing quantum models are discussed.

  10. The Physically Unattractive Child.

    Science.gov (United States)

    Byrnes, Deborah A.

    1987-01-01

    Addresses the issues of the nature of physical attractiveness stereotypes, the root of aesthetic discrimination, and ways in which teachers can help children to accept one another without consideration of physical appearance. (BB)

  11. Dystonia: Physical Therapy

    Science.gov (United States)

    ... accompany the dystonia. Under the guidance of a physical therapist and a physician, an individual may learn to ... the dystonia. For information about locating a local physical therapist who specializes in neurological conditions such as dystonia, ...

  12. Find a Physical Therapist

    Science.gov (United States)

    ... There are numerous benefits to treatment by a physical therapist. Go There » For Patients Choosing Your PT Preparing ... need to know before your appointment with your physical therapist. Go There » Find a PT For Health Professionals ...

  13. Trends in physics 1984

    International Nuclear Information System (INIS)

    Volume 1 of the conference proceedings contains plenary lectures and papers of sessions on non-linear plasma astrophysics, neutrino physics and astrophysics, hard hadron collisions, positron-electron collisions, and atomic and molecular physics. (J.P.)

  14. Physical Activity and Children

    Science.gov (United States)

    ... Food and Beverage Toolkit The AHA's Recommendations for Physical Activity in Children Updated:Jul 21,2016 Click image ... Inactive children are likely to become inactive adults. Physical activity helps with: controlling weight reducing blood pressure raising ...

  15. Teaching introductory physics

    CERN Document Server

    Arons, Arnold B

    1996-01-01

    This book is an invaluable resource for physics teachers. It contains an updated version of the author's A Guide to Introductory Physics Teaching (1990), Homework and Test Questions (1994), and a previously unpublished monograph "Introduction to Classical Conservation Laws".

  16. Medical Physics Panel Discussion

    Science.gov (United States)

    Guèye, Paul; Avery, Steven; Baird, Richard; Soares, Christopher; Amols, Howard; Tripuraneni, Prabhakar; Majewski, Stan; Weisenberger, Drew

    2006-03-01

    The panel discussion will explore opportunities and vistas in medical physics research and practice, medical imaging, teaching medical physics to undergraduates, and medical physics curricula as a recruiting tool for physics departments. Panel members consist of representatives from NSBP (Paul Guèye and Steven Avery), NIH/NIBIB (Richard Baird), NIST (Christopher Soares), AAPM (Howard Amols), ASTRO (Prabhakar Tripuraneni), and Jefferson Lab (Stan Majewski and Drew Weisenberger). Medical Physicists are part of Departments of Radiation Oncology at hospitals and medical centers. The field of medical physics includes radiation therapy physics, medical diagnostic and imaging physics, nuclear medicine physics, and medical radiation safety. It also ranges from basic researcher (at college institutions, industries, and laboratories) to applications in clinical environments.

  17. Theoretical physics division

    International Nuclear Information System (INIS)

    Research activities of the theoretical physics division for 1979 are described. Short summaries are given of specific research work in the following fields: nuclear structure, nuclear reactions, intermediate energy physics, elementary particles

  18. Physics in the Ionosphere.

    Science.gov (United States)

    Murket, A. J.

    1979-01-01

    Develops a simple model of radio wave propagation and illustrates how basic physical concepts such as refractive index, refraction, reflection and dispersion can be applied to a situation normally not met in introductory physics courses. (Author/GA)

  19. Exercises in environmental physics

    CERN Document Server

    Faraoni, Valerio

    2007-01-01

    Presents a collection of problems and exercises in environmental science. This book can be used in many courses in environmental studies especially environmental physics, energy and the environment, and atmospheric physics. The mathematical background is given in an introductory chapter.

  20. Writing about Physics.

    Science.gov (United States)

    Richmond, P. E.

    1980-01-01

    Described are the proceedings from the 1980 annual conference of the Institute of Physics Education Group. The topic of discussion, "writing skills in physics," included teaching writing skills, writing requirements in industry, and writing practice makes perfect. (DS)

  1. Finite size effects in Neutron Star and Nuclear matter simulations

    CERN Document Server

    Molinelli, P A Giménez

    2014-01-01

    In this work we study molecular dynamics simulations of symmetric nuclear matter using a semi-classical nucleon interaction model. We show that, at sub-saturation densities and low temperatures, the solutions are non-homogeneous structures reminiscent of the ``nuclear pasta'' phases expected in Neutron Star Matter simulations, but shaped by artificial aspects of the simulations. We explore different geometries for the periodic boundary conditions imposed on the simulation cell: cube, hexagonal prism and truncated octahedron. We find that different cells may yield different solutions for the same physical conditions (i.e. density and temperature). The particular shape of the solution at a given density can be predicted analytically by energy minimization. We also show that even if this behavior is due to finite size effects, it does not mean that it vanishes for very large systems and it actually is independent of the system size: The system size sets the only characteristic length scale for the inhomogeneitie...

  2. Urban aerosol number size distributions

    Directory of Open Access Journals (Sweden)

    T. Hussein

    2003-10-01

    Full Text Available Aerosol number size distributions were measured continuously in Helsinki, Finland from 5 May 1997 to 28 February 2003. The daily, monthly and annual patterns were investigated. The temporal variation of the particle number concentration was seen to follow the traffic density. The highest total particle number concentrations were usually observed during workdays; especially on Fridays, and the lower concentrations occurred during weekends; especially Sundays. Seasonally, the highest total number concentrations were usually observed during winter and spring and the lowest during June and July. More than 80\\% of the particle number size distributions were tri-modal: nucleation mode (Dp < 30 nm, Aitken mode (20–100 nm and accumulation mode (Dp > 90 nm. Less than 20% of the particle number size distributions have either two modes or consisted of more than three modes. Two different measurement sites are used; in the first place (Siltavuori, 5 May 1997–5 March 2001, the overall means of the integrated particle number concentrations were 7100 cm−3, 6320 cm−3, and 960 cm−3, respectively, for nucleation, Aitken, and accumulation modes. In the second site (Kumpula, 6 March 2001–28 February 2003 they were 5670 cm−3, 4050 cm−3, and 900 cm−3. The total number concentration in nucleation and Aitken modes were usually significantly higher during weekdays than during weekends. The variations in accumulation mode were less pronounced. The smaller concentrations in Kumpula were mainly due to building construction and also slight overall decreasing trend during these years. During the site changing a period of simultaneous measurements over two weeks were performed showing nice correlation in both sites.

  3. Probing new physics with flavor physics (and probing flavor physics with new physics)

    OpenAIRE

    Nir, Yosef

    2007-01-01

    This is a written version of a series of lectures aimed at graduate students and postdoctoral fellows in particle theory/string theory/particle experiment familiar with the basics of the Standard Model. We begin with an overview of flavor physics and its implications for new physics. We emphasize the "new physics flavor puzzle". Then, we give four specific examples of flavor measurements and the lessons that have been (or can be) drawn from them: (i) Charm physics: lessons for supersymmetry f...

  4. CLIC PHYSICS OVERVIEW

    CERN Document Server

    Bozovic-Jelisavcic, Ivanka

    2016-01-01

    In this paper, based on the invited talk at the 17th Lomonosov Conference of Elementary Particle Physics, the physics program at the future Compact Linear Collider (CLIC) will be reviewed, with particular emphasis on the Higgs physics studies. It will be demonstrated, on the basis of detailed physics and detector studies carried out at CLIC, that the CLIC is indeed a precision tool for studies both in the Higgs sector and beyond the Standard Model.

  5. Plasma physics an introduction

    CERN Document Server

    Fitzpatrick, Richard

    2014-01-01

    Plasma Physics: An Introduction is based on a series of university course lectures by a leading name in the field, and thoroughly covers the physics of the fourth state of matter. This book looks at non-relativistic, fully ionized, nondegenerate, quasi-neutral, and weakly coupled plasma. Intended for the student market, the text provides a concise and cohesive introduction to plasma physics theory, and offers a solid foundation for students wishing to take higher level courses in plasma physics.

  6. New physics with beauty

    Indian Academy of Sciences (India)

    Rahul Sinha

    2000-07-01

    We review the effects of new physics on CP asymmetries and decays of mesons. Possible sources and corresponding signals for new physics are studied briefly. We discuss how the decay mode → sℓℓ$ (and → * ℓℓ) will enable us to understand the nature of new physics. We also examine the possibility of truly clean signature of new physics – a signature based on observables alone and without hadronic uncertainties.

  7. Class size versus class composition

    DEFF Research Database (Denmark)

    Jones, Sam

    Raising schooling quality in low-income countries is a pressing challenge. Substantial research has considered the impact of cutting class sizes on skills acquisition. Considerably less attention has been given to the extent to which peer effects, which refer to class composition, also may affect...... outcomes. This study uses new microdata from East Africa, incorporating test score data for over 250,000 children, to compare the likely efficacy of these two types of interventions. Endogeneity bias is addressed via fixed effects and instrumental variables techniques. Although these may not fully mitigate...

  8. Beginning to edit physics

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, P.W.

    1995-02-01

    A physicist-turned-editor shows you the basics required for copyediting physics papers (physical quantities, symbols, units, scientific notation, the structure of mathematical expressions, the nature of graphs), and points the way to learning enough ``editorial physics`` to begin substantive editing.

  9. What Makes Physics Difficult?

    Science.gov (United States)

    Ornek, Funda; Robinson, William R.; Haugan, Mark P.

    2008-01-01

    According to many students, introductory physics is difficult. We are investigating what students believe makes physics difficult and what can be done to overcome these difficulties. Our investigation includes an initial free-response survey given to approximately 1400 students in an introductory physics course and a second survey, which was given…

  10. Astroparticle physics gets organized!

    CERN Multimedia

    2008-01-01

    Astroparticle physics is a rapidly growing field of research at the intersection of astrophysics, particle physics and cosmology. But unlike particle physics it has no permanent organizations like CERN to plan for the long-term future. But this is starting to change, and CERN may be able to help.

  11. Department of Physics

    International Nuclear Information System (INIS)

    Following a list of the academic staff of the Physics Dept., the coursesoffered, seminars held and lectures held by guests, the research activities are very briefly described. These cover nuclear physics, elementary particles and ionospheric physics. Participation by staff members in conferences etc. is listed, as are lectures given by staff members at other academic institutions and reports and articles published. (JIW)

  12. Physics in Literature

    Science.gov (United States)

    Manos, Harry

    2014-01-01

    Physics offers a cross-discipline perspective to understanding other subjects. The purpose of this paper is to provide examples of physics in literature that physics and astronomy teachers can use to give students an indication of the relevance of science as depicted in the humanities. It is not possible to cite the thousands of examples…

  13. Charm physics: theoretical review

    OpenAIRE

    Petrov, Alexey A.

    2003-01-01

    We review recent developments in charm physics, focusing on the physics of charmed mesons. We discuss charm spectroscopy, decay constants, as well as searches for new physics with charmed mesons. We discuss D0-anti-D0 mixing and CP-violation in charm decays. We also present the modified Nelson plot of charm mixing predictions.

  14. Leadership in Freshman Physics

    Science.gov (United States)

    Rebello, Carina M.; Hanuscin, Deborah; Sinha, Somnath

    2011-01-01

    Physics First--a movement to invert the traditional science course sequence to teach physics at the ninth-grade level--is gaining interest. However, there is limited literature exploring how to support teachers in successfully implementing Physics First. To address this, a professional development (PD) program supporting a cadre of teacher-leaders…

  15. FACILITIES FOR PHYSICAL FITNESS.

    Science.gov (United States)

    MUSIAL, STAN

    THIS ARTICLE CITES THE LOW PRIORITY THAT PHYSICAL EDUCATION GENERALLY HAS IN CURRICULUM AND SCHOOL FACILITY PLANNING. IT ALSO CITES THE REASONS FOR DEVELOPING MORE ADEQUATE PHYSICAL EDUCATION FACILITIES--(1) OUR WAY OF LIFE NO LONGER PROVIDES VIGOROUS PHYSICAL ACTIVITY NECESSARY FOR HEALTHY DEVELOPMENT, (2) A DIRECT RELATIONSHIP EXISTS BETWEEN…

  16. Writing for Physics Mastery.

    Science.gov (United States)

    Weber, Stephen W.

    A study examined the effectiveness of incorporating writing as a tool to master the concepts of physics. Subjects were students in the three traditional physics classes and one non-math or conceptual physics class at East High School in Rockford, Illinois. The instructor tried a variety of methods--students wrote criticisms of Carl Sagan videos,…

  17. Whither Nuclear Physics ?

    OpenAIRE

    Abbas, Syed Afsar

    2008-01-01

    Nuclear Physics has had its ups and downs. However in recent years, bucked up by some new and often puzzling data, it has become a potentially very rich field. We review some of these exciting developments in a few important sectors of nuclear physics. Emphasis shall be on the study of exotic nuclei and the new physics that these nuclei are teaching us.

  18. The Physics of Warfare

    Science.gov (United States)

    Giordano, Gerardo

    2015-01-01

    Recently, I was tasked with the creation and execution of a new themed general education physics class called The Physics of Warfare. In the past, I had used the theme of a class, such as the physics of sports medicine, as a way to create homework and in-class activities, generate discussions, and provide an application to demonstrate that physics…

  19. Creativity and Introductory Physics

    Science.gov (United States)

    Guilaran, Ildefonso J.

    2012-01-01

    When I was an undergraduate physics major, I would often stay up late with my physics major roommate as we would digest the physics content we were learning in our courses and explore our respective imaginations armed with our new knowledge. Such activity during my undergraduate years was confined to informal settings, and the first formal…

  20. Association of size at birth with adolescent hormone levels, body size and age at menarche: relevance for breast cancer risk.

    Science.gov (United States)

    Opdahl, S; Nilsen, T I L; Romundstad, P R; Vanky, E; Carlsen, S M; Vatten, L J

    2008-07-01

    Birth size has been positively associated with age at menarche and height in adolescence and adulthood, but the relevant biological mechanisms remain unclear. Among 262 Norwegian term-born singleton girls, birth size measures (weight, length, ponderal index, head circumference and subscapular skin-fold thickness) were analysed in relation to adolescent hormone levels (oestradiol, prolactin, dehydroepiandrosterone sulphate, androstenedione and free testosterone index), age at menarche and adolescent (ages 12.7-15.5 years) and body size (height, weight, body mass index and waist-to-hip ratio) using survival analysis and general linear modelling. The results were adjusted for gestational age at birth, age and menarcheal status at measurement in adolescence and maternal age at menarche. Birth weight, birth length and head circumference were positively associated with adolescent weight and height, and small birth size was associated with earlier age at menarche. Subscapular skin-fold thickness at birth was not associated with adolescent body size, but low fold-thickness was associated with earlier age at menarche. Measures of birth size were inversely related to circulating levels of dehydroepiandrosterone sulphate in adolescence, but there was no clear association with other hormones. These results suggest that physical and sexual development in puberty and adolescence is influenced by prenatal factors, and in combination, these factors may influence health and disease later in life. PMID:18594544

  1. Radiation Oncology Physics and Medical Physics Education

    Science.gov (United States)

    Bourland, Dan

    2011-10-01

    Medical physics, an applied field of physics, is the applications of physics in medicine. Medical physicists are essential professionals in contemporary healthcare, contributing primarily to the diagnosis and treatment of diseases through numerous inventions, advances, and improvements in medical imaging and cancer treatment. Clinical service, research, and teaching by medical physicists benefits thousands of patients and other individuals every day. This talk will cover three main topics. First, exciting current research and development areas in the medical physics sub-specialty of radiation oncology physics will be described, including advanced oncology imaging for treatment simulation, image-guided radiation therapy, and biologically-optimized radiation treatment. Challenges in patient safety in high-technology radiation treatments will be briefly reviewed. Second, the educational path to becoming a medical physicist will be reviewed, including undergraduate foundations, graduate training, residency, board certification, and career opportunities. Third, I will introduce the American Association of Physicists in Medicine (AAPM), which is the professional society that represents, advocates, and advances the field of medical physics (www.aapm.org).

  2. Exploring Explanations of Subglacial Bedform Sizes Using Statistical Models.

    Directory of Open Access Journals (Sweden)

    John K Hillier

    Full Text Available Sediments beneath modern ice sheets exert a key control on their flow, but are largely inaccessible except through geophysics or boreholes. In contrast, palaeo-ice sheet beds are accessible, and typically characterised by numerous bedforms. However, the interaction between bedforms and ice flow is poorly constrained and it is not clear how bedform sizes might reflect ice flow conditions. To better understand this link we present a first exploration of a variety of statistical models to explain the size distribution of some common subglacial bedforms (i.e., drumlins, ribbed moraine, MSGL. By considering a range of models, constructed to reflect key aspects of the physical processes, it is possible to infer that the size distributions are most effectively explained when the dynamics of ice-water-sediment interaction associated with bedform growth is fundamentally random. A 'stochastic instability' (SI model, which integrates random bedform growth and shrinking through time with exponential growth, is preferred and is consistent with other observations of palaeo-bedforms and geophysical surveys of active ice sheets. Furthermore, we give a proof-of-concept demonstration that our statistical approach can bridge the gap between geomorphological observations and physical models, directly linking measurable size-frequency parameters to properties of ice sheet flow (e.g., ice velocity. Moreover, statistically developing existing models as proposed allows quantitative predictions to be made about sizes, making the models testable; a first illustration of this is given for a hypothesised repeat geophysical survey of bedforms under active ice. Thus, we further demonstrate the potential of size-frequency distributions of subglacial bedforms to assist the elucidation of subglacial processes and better constrain ice sheet models.

  3. Exploring Explanations of Subglacial Bedform Sizes Using Statistical Models.

    Science.gov (United States)

    Hillier, John K; Kougioumtzoglou, Ioannis A; Stokes, Chris R; Smith, Michael J; Clark, Chris D; Spagnolo, Matteo S

    2016-01-01

    Sediments beneath modern ice sheets exert a key control on their flow, but are largely inaccessible except through geophysics or boreholes. In contrast, palaeo-ice sheet beds are accessible, and typically characterised by numerous bedforms. However, the interaction between bedforms and ice flow is poorly constrained and it is not clear how bedform sizes might reflect ice flow conditions. To better understand this link we present a first exploration of a variety of statistical models to explain the size distribution of some common subglacial bedforms (i.e., drumlins, ribbed moraine, MSGL). By considering a range of models, constructed to reflect key aspects of the physical processes, it is possible to infer that the size distributions are most effectively explained when the dynamics of ice-water-sediment interaction associated with bedform growth is fundamentally random. A 'stochastic instability' (SI) model, which integrates random bedform growth and shrinking through time with exponential growth, is preferred and is consistent with other observations of palaeo-bedforms and geophysical surveys of active ice sheets. Furthermore, we give a proof-of-concept demonstration that our statistical approach can bridge the gap between geomorphological observations and physical models, directly linking measurable size-frequency parameters to properties of ice sheet flow (e.g., ice velocity). Moreover, statistically developing existing models as proposed allows quantitative predictions to be made about sizes, making the models testable; a first illustration of this is given for a hypothesised repeat geophysical survey of bedforms under active ice. Thus, we further demonstrate the potential of size-frequency distributions of subglacial bedforms to assist the elucidation of subglacial processes and better constrain ice sheet models. PMID:27458921

  4. Exploring Explanations of Subglacial Bedform Sizes Using Statistical Models

    Science.gov (United States)

    Kougioumtzoglou, Ioannis A.; Stokes, Chris R.; Smith, Michael J.; Clark, Chris D.; Spagnolo, Matteo S.

    2016-01-01

    Sediments beneath modern ice sheets exert a key control on their flow, but are largely inaccessible except through geophysics or boreholes. In contrast, palaeo-ice sheet beds are accessible, and typically characterised by numerous bedforms. However, the interaction between bedforms and ice flow is poorly constrained and it is not clear how bedform sizes might reflect ice flow conditions. To better understand this link we present a first exploration of a variety of statistical models to explain the size distribution of some common subglacial bedforms (i.e., drumlins, ribbed moraine, MSGL). By considering a range of models, constructed to reflect key aspects of the physical processes, it is possible to infer that the size distributions are most effectively explained when the dynamics of ice-water-sediment interaction associated with bedform growth is fundamentally random. A ‘stochastic instability’ (SI) model, which integrates random bedform growth and shrinking through time with exponential growth, is preferred and is consistent with other observations of palaeo-bedforms and geophysical surveys of active ice sheets. Furthermore, we give a proof-of-concept demonstration that our statistical approach can bridge the gap between geomorphological observations and physical models, directly linking measurable size-frequency parameters to properties of ice sheet flow (e.g., ice velocity). Moreover, statistically developing existing models as proposed allows quantitative predictions to be made about sizes, making the models testable; a first illustration of this is given for a hypothesised repeat geophysical survey of bedforms under active ice. Thus, we further demonstrate the potential of size-frequency distributions of subglacial bedforms to assist the elucidation of subglacial processes and better constrain ice sheet models. PMID:27458921

  5. Physical stability of caseinate stabilized emulsions during heating.

    NARCIS (Netherlands)

    Cruijsen, J.M.M.

    1996-01-01

    The physical stability of caseinate stabilized emulsions was studied during heating (80- 120°C). Coagulation, coalescence and phase separation of the caseinate emulsions was studied using objective heat stability tests. The physical changes were characterized by light microscopy, particle size measu

  6. Physical Attractiveness and Health in Western Societies: A Review

    Science.gov (United States)

    Weeden, Jason; Sabini, John

    2005-01-01

    Evidence from developed Western societies is reviewed for the claims that (a) physical attractiveness judgments are substantially based on body size and shape, symmetry, sex-typical hormonal markers, and other specific cues and (b) physical attractiveness and these cues substantially predict health. Among the cues that the authors review, only…

  7. Nuclear genome size in Selaginella.

    Science.gov (United States)

    Little, Damon P; Moran, Robbin C; Brenner, Eric D; Stevenson, Dennis Wm

    2007-04-01

    Estimates of nuclear genome size for 9 Selaginella species were obtained using flow cytometry, and measurements for 7 of these species are reported for the first time. Estimates range from 0.086 to 0.112 pg per holoploid genome (84-110 Mb). The data presented here agree with the previously published flow cytometric results for S. moellendorffii. Within the 9 species sampled here, chromosome number varies from 2n = 16 to 2n = 27. Nuclear genome size appears to be strongly correlated with chromosome number (Spearman's rank correlation; p = 0.00003725). Cultivated S. moellendorffii lacks sexual reproduction--manifest by the production of abortive megasporangia. Flow cytometric data generated from a herbarium specimen of a fertile wild-collected S. moellendorffii are virtually indistinguishable from the data generated from fresh material (0.088 vs. 0.089 pg/1C). Therefore, the limited fertility observed in cultivated plants is probably not the result of abnormal chromosome number (e.g., induced by interspecific hybridization). PMID:17546093

  8. The size of the proton

    Energy Technology Data Exchange (ETDEWEB)

    Nebel, T., E-mail: tbn@mpq.mpg.de [Max-Planck-Institut fuer Quantenoptik (Germany); Antognini, A. [ETH Zuerich (Switzerland); Amaro, F. D. [Universidade de Coimbra, Departamento de Fisica (Portugal); Biraben, F. [Ecole Normale Superieure, CNRS, Laboratoire Kastler Brossel (France); Cardoso, J. M. R. [Universidade de Coimbra, Departamento de Fisica (Portugal); Covita, D. S. [Universidade de Aveiro, I3N, Departamento de Fisica (Portugal); Dax, A.; Dhawan, S. [Yale University, Physics Department (United States); Fernandes, L. M. P. [Universidade de Coimbra, Departamento de Fisica (Portugal); Giesen, A. [Dausinger and Giesen GmbH (Germany); Graf, T. [Universitaet Stuttgart, Institut fuer Strahlwerkzeuge (Germany); Haensch, T. W. [Max-Planck-Institut fuer Quantenoptik (Germany); Indelicato, P.; Julien, L. [Ecole Normale Superieure, CNRS, Laboratoire Kastler Brossel (France); Kao, C.-Y. [National Tsing Hua University, Physics Department (China); Knowles, P. [Universite de Fribourg, Departement de Physique (Switzerland); Kottmann, F. [ETH Zuerich, Institut fuer Teilchenphysik (Switzerland); Bigot, E. Le [Ecole Normale Superieure, CNRS, Laboratoire Kastler Brossel (France); Liu, Y.-W. [National Tsing Hua University, Physics Department (China); Lopes, J. A. M. [Universidade de Coimbra, Departamento de Fisica (Portugal); and others

    2012-12-15

    The root-mean-square (rms) charge radius r{sub p} of the proton has so far been known only with a surprisingly low precision of about 1% from both electron scattering and precision spectroscopy of hydrogen. We have recently determined r{sub p} by means of laser spectroscopy of the Lamb shift in the exotic 'muonic hydrogen' atom. Here, the muon, which is the 200 times heavier cousin of the electron, orbits the proton with a 200 times smaller Bohr radius. This enhances the sensitivity to the proton's finite size tremendously. Our new value r{sub p} = 0.84184 (67) fm is ten times more precise than the generally accepted CODATA-value, but it differs by 5 standard deviations from it. A lively discussion about possible solutions to the 'proton size puzzle' has started. Our measurement, together with precise measurements of the 1S-2S transition in regular hydrogen and deuterium, also yields improved values of the Rydberg constant, R{sub {infinity} } = 10,973,731.568160 (16) m{sup - 1}.

  9. Height, body size and longevity.

    Directory of Open Access Journals (Sweden)

    Samaras TT

    1999-08-01

    Full Text Available Life expectancy, mortality and longevity data related to height and body size for various US and world population samples are reviewed. Research on energy restriction, smaller body size and longevity is also examined. Information sources include various medical and scientific journals, books and personal communications with researchers. Additional information is presented based on research involving eight populations of the world noted for their health, vigor and longevity. This information includes the findings of one of the authors who led research teams to study these populations. While conflicting findings exist on the cardiovascular death rates for shorter people, many examples of short populations with very little heart disease are described. Most cancer studies indicate that shorter people have significantly lower mortality risk. Considerable data suggest that shorter people generally have greater longevity than taller people, and extensive animal research supports human longevity findings. Tall populations with low mortality rates are also described. Shorter stature and smaller body weight appear to promote better health and longevity in the absence of malnutrition and infectious diseases. Several theoretical reasons for this greater longevity potential are covered. Also discussed, is the role of socioeconomic status, diet, relative weight, environment and other factors in increasing or decreasing the longevity of individuals, regardless of their heights and weights.

  10. A system for aerodynamically sizing ultrafine environmental radioactive particles

    Energy Technology Data Exchange (ETDEWEB)

    Olawoyin, L.

    1995-09-01

    The unattached environmental radioactive particles/clusters, produced mainly by {sup 222}Rn in indoor air, are usually few nanometers in size. The inhalation of these radioactive clusters can lead to deposition of radioactivity on the mucosal surface of the tracheobronchial tree. The ultimate size of the cluster together with the flow characteristics will determine the depositional site in the human lung and thus, the extent of damage that can be caused. Thus, there exists the need for the determination of the size of the radioactive clusters. However, the existing particle measuring device have low resolution in the sub-nanometer range. In this research, a system for the alternative detection and measurement of the size of particles/cluster in the less than 2 nm range have been developed. The system is a one stage impactor which has a solid state spectrometer as its impaction plate. It`s major feature is the nozzle-to-plate separation, L. The particle size collected changes with L and thus, particle size spectroscopy is achieved by varying L. The number of collected particles is determined by alpha spectroscopy. The size-discriminating ability of the system was tested with laboratory generated radon particles and it was subsequently used to characterize the physical (size) changes associated with the interaction of radon progeny with water vapor and short chain alcohols in various support gases. The theory of both traditional and high velocity jet impactors together with the design and evaluation of the system developed in this study are discussed in various chapters of this dissertation. The major results obtained in the course of the study are also presented.

  11. A system for aerodynamically sizing ultrafine environmental radioactive particles

    International Nuclear Information System (INIS)

    The unattached environmental radioactive particles/clusters, produced mainly by 222Rn in indoor air, are usually few nanometers in size. The inhalation of these radioactive clusters can lead to deposition of radioactivity on the mucosal surface of the tracheobronchial tree. The ultimate size of the cluster together with the flow characteristics will determine the depositional site in the human lung and thus, the extent of damage that can be caused. Thus, there exists the need for the determination of the size of the radioactive clusters. However, the existing particle measuring device have low resolution in the sub-nanometer range. In this research, a system for the alternative detection and measurement of the size of particles/cluster in the less than 2 nm range have been developed. The system is a one stage impactor which has a solid state spectrometer as its impaction plate. It's major feature is the nozzle-to-plate separation, L. The particle size collected changes with L and thus, particle size spectroscopy is achieved by varying L. The number of collected particles is determined by alpha spectroscopy. The size-discriminating ability of the system was tested with laboratory generated radon particles and it was subsequently used to characterize the physical (size) changes associated with the interaction of radon progeny with water vapor and short chain alcohols in various support gases. The theory of both traditional and high velocity jet impactors together with the design and evaluation of the system developed in this study are discussed in various chapters of this dissertation. The major results obtained in the course of the study are also presented

  12. Size distribution measurements and chemical analysis of aerosol components

    Energy Technology Data Exchange (ETDEWEB)

    Pakkanen, T.A.

    1995-12-31

    The principal aims of this work were to improve the existing methods for size distribution measurements and to draw conclusions about atmospheric and in-stack aerosol chemistry and physics by utilizing size distributions of various aerosol components measured. A sample dissolution with dilute nitric acid in an ultrasonic bath and subsequent graphite furnace atomic absorption spectrometric analysis was found to result in low blank values and good recoveries for several elements in atmospheric fine particle size fractions below 2 {mu}m of equivalent aerodynamic particle diameter (EAD). Furthermore, it turned out that a substantial amount of analyses associated with insoluble material could be recovered since suspensions were formed. The size distribution measurements of in-stack combustion aerosols indicated two modal size distributions for most components measured. The existence of the fine particle mode suggests that a substantial fraction of such elements with two modal size distributions may vaporize and nucleate during the combustion process. In southern Norway, size distributions of atmospheric aerosol components usually exhibited one or two fine particle modes and one or two coarse particle modes. Atmospheric relative humidity values higher than 80% resulted in significant increase of the mass median diameters of the droplet mode. Important local and/or regional sources of As, Br, I, K, Mn, Pb, Sb, Si and Zn were found to exist in southern Norway. The existence of these sources was reflected in the corresponding size distributions determined, and was utilized in the development of a source identification method based on size distribution data. On the Finnish south coast, atmospheric coarse particle nitrate was found to be formed mostly through an atmospheric reaction of nitric acid with existing coarse particle sea salt but reactions and/or adsorption of nitric acid with soil derived particles also occurred. Chloride was depleted when acidic species reacted

  13. A phylogenetic analysis of egg size, clutch size, spawning mode, adult body size, and latitude in reef fishes

    Science.gov (United States)

    Kasimatis, Katja; Riginos, Cynthia

    2016-06-01

    Theoretical treatments of egg size in fishes suggest that constraints on reproductive output should create trade-offs between the size and number of eggs produced per spawn. For marine reef fishes, the observation of distinct reproductive care strategies (demersal guarding, egg scattering, and pelagic spawning) has additionally prompted speculation that these strategies reflect alternative fitness optima with selection on egg size differing by reproductive mode and perhaps latitude. Here, we aggregate data from 278 reef fish species and test whether clutch size, reproductive care, adult body size, and latitudinal bands (i.e., tropical, subtropical, and temperate) predict egg size, using a statistically unified framework that accounts for phylogenetic correlations among traits. We find no inverse relationship between species egg size and clutch size, but rather that egg size differs by reproductive mode (mean volume for demersal eggs = 1.22 mm3, scattered eggs = 0.18 mm3, pelagic eggs = 0.52 mm3) and that clutch size is strongly correlated with adult body size. Larger eggs were found in temperate species compared with tropical species in both demersal guarders and pelagic spawners, but this difference was not strong when accounting for phylogenetic correlations, suggesting that differences in species composition underlies regional differences in egg size. In summary, demersal guarders are generally small fishes with small clutch sizes that produce large eggs. Pelagic spawners and egg scatterers are variable in adult and clutch size. Although pelagic spawned eggs are variable in size, those of scatterers are consistently small.

  14. Computing in the Introductory Physics Course

    Science.gov (United States)

    Chabay, Ruth; Sherwood, Bruce

    2004-03-01

    In the Matter & Interactions version of the calculus-based introductory physics course (http://www4.ncsu.edu/ ˜rwchabay/mi) , students write programs in VPython (http://vpython.org) to model physical systems and to calculate and visualize electric and magnetic fields. VPython is unusually easy to learn, produces navigable 3D animations as a side effect of physics computations, and supports full vector calculations. The high speed of current computers makes sophisticated numerical analysis techniques unnecessary. Students can use simple first-order Euler integration, cutting the step size until the behavior of the system no longer changes. In mechanics, iterative application of the momentum principle gives students a sense of the time-evolution character of Newton's second law which is usually missing from the standard course. In E, students calculate electric and magnetic fields numerically and display them in 3D. We are currently studying the impact of introducing computational physics into the introductory course.

  15. Physics of condensed matter

    CERN Document Server

    Misra, Prasanta K

    2012-01-01

    Physics of Condensed Matter is designed for a two-semester graduate course on condensed matter physics for students in physics and materials science. While the book offers fundamental ideas and topic areas of condensed matter physics, it also includes many recent topics of interest on which graduate students may choose to do further research. The text can also be used as a one-semester course for advanced undergraduate majors in physics, materials science, solid state chemistry, and electrical engineering, because it offers a breadth of topics applicable to these majors. The book be

  16. Space physics educational outreach

    Science.gov (United States)

    Copeland, Richard A.

    1995-01-01

    The goal of this Space Physics Educational Outreach project was to develop a laboratory experiment and classroom lecture on Earth's aurora for use in lower division college physics courses, with the particular aim of implementing the experiment and lecture at Saint Mary's College of California. The strategy is to teach physics in the context of an interesting natural phenomenon by investigating the physical principles that are important in Earth's aurora, including motion of charged particles in electric and magnetic fields, particle collisions and chemical reactions, and atomic and molecular spectroscopy. As a by-product, the undergraduate students would develop an appreciation for naturally occurring space physics phenomena.

  17. Physics The First Science

    CERN Document Server

    LINDENFELD, Peter

    2011-01-01

    Today's physics textbooks have become encyclopedic, offering students dry discussions, rote formulas, and exercises with little relation to the real world. Physics: The First Science offers uniquely accessible, student-friendly explanations, historical and philosophical perspectives and mathematics in easy-to-comprehend dialogue. It emphasizes the unity of physics and its place as the basis for all science. With their experience instructing both students and teachers of physics for decades, Peter Lindenfeld and Suzanne White Brahmia have developed an algebra-based physics book with fea

  18. The Basics of Physics

    CERN Document Server

    Myers, Richard L

    2005-01-01

    Students will be introduced to the science of physics, and its applications to everyday life, in this volume. Tracing its development from antiquity to the present, the author examines all aspects of physics including motion, work, energy, heat, matter, light, and electricity. Quantum & Nuclear physics are also included. The chapter with instructions for experiments in physics will assist students in projects for science fairs, and the chapter on physics as a career will help students to explore the various options for working in this field of science. A glossary, conversion table, and list of

  19. Nuclear medicine physics

    CERN Document Server

    De Lima, Joao Jose

    2011-01-01

    Edited by a renowned international expert in the field, Nuclear Medicine Physics offers an up-to-date, state-of-the-art account of the physics behind the theoretical foundation and applications of nuclear medicine. It covers important physical aspects of the methods and instruments involved in modern nuclear medicine, along with related biological topics. The book first discusses the physics of and machines for producing radioisotopes suitable for use in conventional nuclear medicine and PET. After focusing on positron physics and the applications of positrons in medicine and biology, it descr

  20. Physics imagination and reality

    CERN Document Server

    Wallace, Philip Russell

    1991-01-01

    Physics: Imagination and Reality introduces the reader to major ideas and the conceptual structure of modern physics, by tracing its development from the introduction of fields into physics by Faraday and Maxwell in the last century. Because the approach is historical, the book provides a comprehensive overview of the subjects. It should appeal to anyone interested in a basic understanding of the contemporary physicists view of the physical world. It avoids all but the simplest mathematics and presents ideas and concepts in everyday language.Physics: Imagination and Reality attempts to provide

  1. The MCAT Physics Book

    CERN Document Server

    Biehle, Garrett

    2012-01-01

    Comprehensive, Rigorous Prep for MCAT Physics. The MCAT Physics Book offers the most comprehensive and rigorous analysis of MCAT physics available. Including,. Features:. * 500 MCAT-style practice problems and detailed solutions to all problems. * 49 MCAT-style passages. Illustrations and tables are included wherever necessary to focus and clarify key ideas and concepts. Dr. Biehle's classic MCAT Physics Book presents a clear, insightful analysis of MCAT physics. His lively prose and subtle wit make this challenging topic more palatable. Dr. Biehle received his Ph.D. from Caltech (California I

  2. Advances in chemical physics

    CERN Document Server

    Rice, Stuart A

    2014-01-01

    Advances in Chemical Physics is the only series of volumes available that explores the cutting edge of research in chemical physics. This is the only series of volumes available that presents the cutting edge of research in chemical physics.Includes contributions from experts in this field of research.Contains a representative cross-section of research that questions established thinking on chemical solutions.Structured with an editorial framework that makes the book an excellent supplement to an advanced graduate class in physical chemistry or chemical physics.

  3. Division of atomic physics

    International Nuclear Information System (INIS)

    The Division of Atomic Physics, Lund Institute of Technology (LTH), is responsible for the basic physics teaching in all subjects at LTH and for specialized teaching in Optics, Atomic Physics, Atomic and Molecular Spectroscopy and Laser Physics. The Division has research activities in basic and applied optical spectroscopy, to a large extent based on lasers. It is also part of the Physics Department, Lund University, where it forms one of eight divisions. Since the beginning of 1980 the research activities of our division have been centred around the use of lasers. The activities during the period 1991-1992 is described in this progress reports

  4. Numerical problems in physics

    CERN Document Server

    Singh, Devraj

    2015-01-01

    Numerical Problems in Physics, Volume 1 is intended to serve the need of the students pursuing graduate and post graduate courses in universities with Physics and Materials Science as subject including those appearing in engineering, medical, and civil services entrance examinations. KEY FEATURES: * 29 chapters on Optics, Wave & Oscillations, Electromagnetic Field Theory, Solid State Physics & Modern Physics * 540 solved numerical problems of various universities and ompetitive examinations * 523 multiple choice questions for quick and clear understanding of subject matter * 567 unsolved numerical problems for grasping concepts of the various topic in Physics * 49 Figures for understanding problems and concept

  5. Physics Essentials For Dummies

    CERN Document Server

    Holzner, Steven

    2010-01-01

    For students who just need to know the vital concepts of physics, whether as a refresher, for exam prep, or as a reference, Physics Essentials For Dummies is a must-have guide. Free of ramp-up and ancillary material, Physics Essentials For Dummies contains content focused on key topics only. It provides discrete explanations of critical concepts taught in an introductory physics course, from force and motion to momentum and kinetics. This guide is also a perfect reference for parents who need to review critical physics concepts as they help high school students with homework assignments, as we

  6. 7 CFR 51.1903 - Size classification.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Size classification. 51.1903 Section 51.1903... STANDARDS) United States Consumer Standards for Fresh Tomatoes Size and Maturity Classification § 51.1903 Size classification. The following terms may be used for describing the size of the tomatoes in any...

  7. 7 CFR 51.1402 - Size classification.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Size classification. 51.1402 Section 51.1402... STANDARDS) United States Standards for Grades of Pecans in the Shell 1 Size Classification § 51.1402 Size classification. Size of pecans may be specified in connection with the grade in accordance with one of...

  8. Sample size: from formulae to concepts - II

    Directory of Open Access Journals (Sweden)

    Rakesh R. Pathak

    2013-02-01

    Full Text Available Sample size formulae need some input data or to say it otherwise we need some parameters to calculate sample size. This second part on the formula explanation gives ideas of Z, population size, precision of error, standard deviation, contingency etc which influence sample size. [Int J Basic Clin Pharmacol 2013; 2(1.000: 94-95

  9. Spatiotemporal relationship between adult census size and genetic population size across a wide population size gradient.

    Science.gov (United States)

    Bernos, Thaїs A; Fraser, Dylan J

    2016-09-01

    Adult census population size (N) and effective number of breeders (Nb ) are highly relevant for designing effective conservation strategies. Both parameters are often challenging to quantify, however, making it of interest to determine whether one parameter can be generalized from the other. Yet, the spatiotemporal relationship between N and Nb has not been well characterized empirically in many taxa. We analysed this relationship for 5-7 consecutive years in twelve brook trout populations varying greatly in N (49-10032) and Nb (3-567) and identified major environmental variables affecting the two parameters. N or habitat size alone explained 47-57% of the variance in Nb , and Nb was strongly correlated with effective population size. The ratio Nb /N ranged from 0.01 to 0.45 and increased at small N or following an annual decrease in N, suggesting density-dependent constraints on Nb . We found no evidence for a consistent, directional difference between variability in Nb and/or Nb /N among small and large populations; however, small populations had more varying temporal variability in Nb /N ratios than large populations. Finally, Nb and Nb /N were 2.5- and 2.3-fold more variable among populations than temporally within populations. Our results demonstrate a clear linkage between demographic and evolutionary parameters, suggesting that Nb could be used to approximate N (or vice versa) in natural populations. Nevertheless, using one variable to infer the other to monitor trends within populations is less recommended, perhaps even less so in small populations given their less predictable Nb vs. N dynamics. PMID:27483203

  10. Population Genetics with Fluctuating Population Sizes

    CERN Document Server

    Chotibut, Thiparat

    2016-01-01

    Standard neutral population genetics theory with a strictly fixed population size has important limitations. An alternative model that allows independently fluctuating population sizes and reproduces the standard neutral evolution is reviewed. We then study a situation such that the competing species are neutral at the equilibrium population size but population size fluctuations nevertheless favor fixation of one species over the other. In this case, a separation of timescales emerges naturally and allows adiabatic elimination of a fast population size variable to deduce the fluctuations-induced selection dynamics near the equilibrium population size. The results highlight the incompleteness of the standard population genetics with a strictly fixed population size.

  11. Polish Nuclear Physics Network

    International Nuclear Information System (INIS)

    In June 2002 the representatives of thirteen Polish nuclear physics units decided to create Polish Nuclear Physics Network (PNPN) and to contact Czech Republic, Hungary and Slovakia with a suggestion to establish a larger network of nuclear physics laboratories in these countries and in Poland. In spring 2003 North-East European Network (NEEN) was established. Its planned networking activities, their objectives and expected outcomes were submitted to EURONS Coordinator. During the same period the nuclear physics laboratories from Bulgaria, Croatia, Greece, Romania, Serbia and Turkey formed South-East European Network (SEEN) and also applied for EURONS support. Eventually, following the EURONS advice, the merge of NEEN and SEEN was decided by representatives of both networks and, in 2004, a common network EWON (East - West Outreach) was included in the EURONS initiative. The indicated EU financial contribution to EWON includes only the support of NEEN, whereas SEEN, for practical reasons, is financed separately. The nuclear physics activity in Poland can be conveniently divided into a few subgroups: - experimental nuclear physics using local facilities; - experimental nuclear physics using external facilities; - theoretical nuclear physics; - applications of nuclear physics to other domains of science; - medical applications. Most of these activities are presented in this report, at least partly, in the form of review articles and short communications. The special place in the Polish nuclear physics landscape occupies the theoretical physics. Not limited by severe financial restrictions which affects local experimental facilities, the flourishing of this domain is especially evident in the nuclear structure theory

  12. Quantum physics for dummies

    CERN Document Server

    Holzner, Steve

    2013-01-01

    Quantum Physics For Dummies, Revised Edition helps make quantum physics understandable and accessible. From what quantum physics can do for the world to understanding hydrogen atoms, readers will get complete coverage of the subject, along with numerous examples to help them tackle the tough equations. Compatible with classroom text books and courses, Quantum Physics For Dummies, Revised Edition lets students study at their own paces and helps them prepare for graduate or professional exams. Coverage includes: The Schrodinger Equation and its Applications The Foundations of Quantum Physics Vector Notation Spin Scattering Theory, Angular Momentum, and more From the Back Cover Your plain-English guide to understanding and working with the micro world Quantum physics -- also called quantum mechanics or quantum field theory -- can be daunting for even the most dedicated student or enthusiast of science, math, or physics. This friendly, concise guide makes this challenging subject understandable and accessible, fr...

  13. Physics of Baseball & Softball

    CERN Document Server

    Cross, Rod

    2011-01-01

    This book describes the physics of baseball and softball, assuming that the reader has a background in both physics and mathematics at the high school level. The physics is explained in a conversational style, and illustrated with experimental results obtained both in the laboratory and in the field. Simple equations are also used in order to model the experimental results and to test whether the explanations are actually valid. The subject matter provides an excellent opportunity to explain physics in an interesting manner, given the universal popularity of baseball and softball as pastimes. There is also the interaction between a bat and ball, which is a classic problem in physics involving large forces, short time intervals, momentum, and energy transfer, vibration, rotation, and the different physical properties of the wood (or aluminum) of the bat, and the ball. The flight of the ball through the air is another fascinating example of physics in action, involving the effects of gravity, air resistance and...

  14. More than just skin deep? Personality information influences men's ratings of the attractiveness of women's body sizes.

    Science.gov (United States)

    Swami, Viren; Furnham, Adrian; Chamorro-Premuzic, Tomas; Akbar, Kanwal; Gordon, Natalie; Harris, Tasha; Finch, Jo; Tovée, Martin J

    2010-01-01

    This study examined the influence of personality information on perceptions of the physical attractiveness of a range of female body sizes. A sample of 2,157 male university students were randomly assigned to one of 10 groups in which they received personality information about women they were rating, or a control group in which they received no personality information. Controlling for participants' age and body mass index, results showed no significant between-group differences in the body size that participants found most attractive. However, participants provided with positive personality information perceived a wider range of body sizes as physically attractive compared with the control group, whereas participants provided with negative personality information perceived a narrower range of body sizes as attractive. Correlations showed that participants' own Extraversion was associated with their body size ratings. These results suggest that non-physical cues have an influence on the perception of physical beauty.

  15. Education, Birth Order, and Family Size

    OpenAIRE

    Bagger, Jesper; Birchenall, Javier A.; Mansour, Hani; Urzua, Sergio

    2013-01-01

    We introduce a general framework to analyze the trade-off between education and family size. Our framework incorporates parental preferences for birth order and delivers theoretically consistent birth order and family size effects on children's educational attainment. We develop an empirical strategy to identify these effects. We show that the coefficient on family size in a regression of educational attainment on birth order and family size does not identify the family size effect as defined...

  16. On the heritability of geographic range sizes

    OpenAIRE

    Webb, T. J.; Gaston, K J

    2003-01-01

    Within taxonomic groups, most species are restricted in their geographic range sizes, with only a few being widespread. The possibility that species-level selection on range sizes contributes to the characteristic form of such speciesrange size distributions has previously been raised. This would require that closely related species have similar range sizes, an indication of "heritability" of range sizes at the species level. Support for this view came from a positive correlation between the ...

  17. Influence of feedstock particle size on lignocellulose conversion--a review.

    Science.gov (United States)

    Vidal, Bernardo C; Dien, Bruce S; Ting, K C; Singh, Vijay

    2011-08-01

    Feedstock particle sizing can impact the economics of cellulosic ethanol commercialization through its effects on conversion yield and energy cost. Past studies demonstrated that particle size influences biomass enzyme digestibility to a limited extent. Physical size reduction was able to increase conversion rates to maximum of ≈ 50%, whereas chemical modification achieved conversions of >70% regardless of biomass particle size. This suggests that (1) mechanical pretreatment by itself is insufficient to attain economically feasible biomass conversion, and, therefore, (2) necessary particle sizing needs to be determined in the context of thermochemical pretreatment employed for lignocellulose conversion. Studies of thermochemical pretreatments that have taken into account particle size as a factor have exhibited a wide range of maximal sizes (i.e., particle sizes below which no increase in pretreatment effectiveness, measured in terms of the enzymatic conversion resulting from the pretreatment, were observed) from pretreatment employed, with maximal size range decreasing as follows: steam explosion > liquid hot water > dilute acid and base pretreatments. Maximal sizes also appeared dependent on feedstock, with herbaceous or grassy biomass exhibiting lower maximal size range (biomass (>3 mm). Such trends, considered alongside the intensive energy requirement of size reduction processes, warrant a more systematic study of particle size effects across different pretreatment technologies and feedstock, as a requisite for optimizing the feedstock supply system.

  18. Thermal Properties, Sizes, and Size Distribution of Jupiter-Family Cometary Nuclei

    CERN Document Server

    Fernandez, Y R; Lamy, P L; Toth, I; Groussin, O; Lisse, C M; A'Hearn, M F; Bauer, J M; Campins, H; Fitzsimmons, A; Licandro, J; Lowry, S C; Meech, K J; Pittichova, J; Reach, W T; Snodgrass, C; Weaver, H A

    2013-01-01

    We present results from SEPPCoN, an on-going Survey of the Ensemble Physical Properties of Cometary Nuclei. In this report we discuss mid-infrared measurements of the thermal emission from 89 nuclei of Jupiter-family comets (JFCs). All data were obtained in 2006 and 2007 with the Spitzer Space Telescope. For all 89 comets, we present new effective radii, and for 57 comets we present beaming parameters. Thus our survey provides the largest compilation of radiometrically-derived physical properties of nuclei to date. We conclude the following. (a) The average beaming parameter of the JFC population is 1.03+/-0.11, consistent with unity, and indicating low thermal inertia. (b) The known JFC population is not complete even at 3 km radius, and even for comets with perihelia near ~2 AU. (c) We find that the JFC nuclear cumulative size distribution (CSD) has a power-law slope of around -1.9. (d) This power-law is close to that derived from visible-wavelength observations, suggesting that there is no strong dependenc...

  19. The Physics Force presents The Physics Circus

    Science.gov (United States)

    Dahlberg, E. Dan

    2015-03-01

    The Physics Force of the University of Minnesota is an outreach program developed with the goal to show students and the public Science is Fun, Science is Interesting, and Science is Understandable. The program grew from a rather small effort by three high school physics teachers and two University of Minnesota staff members. In the almost three decades since its humble beginnings of 100 attendees in a year, it has grown to an average attendance of over 36,000 annually. In the last three years alone, about 110,000 Minnesotans have seen a performance of The Physics Circus which is roughly 2% of the population of the state. In addition to the performances in Minnesota, The Force performed two years at Disney's Epcot Center, was featured on Newton's Apple, and made appearances on the very successful German TV science show, the Knoff-Hoff Show. I will begin the talk with some of our motivation to develop The Physics Force arising from the current ``scientific state'' of our society and then provide more information on The Force including both some history and examples taken from our Physics Circus.

  20. Reducing costs by reducing size

    International Nuclear Information System (INIS)

    The present paper discusses briefly the many factors, including capital cost, which have to be taken into account in determining whether a series of power stations based on a small nuclear plant can be competitive with a series based on traditional large unit sizes giving the guaranteed level of supply. The 320 MWe UK/US Safe Integral Reactor is described as a good example of how the factors discussed can be beneficially incorporated into a design using proven technology. Finally it goes on to illustrate how the overall costs of a generating system can indeed by reduced by use of the 320 MWe Safe Integral Reactor rather than conventional units of around 1200 MWe. (author). 9 figs

  1. A comparative study of middle school and high school students' views about physics and learning physics

    Science.gov (United States)

    Ding, Lin

    2013-01-01

    Previous studies of student epistemological beliefs about physics and learning physics focused on college and post-college students in Western countries. However, little is known about early-grade students in Asian countries. This paper reports Chinese middle and high school students' views about the nature of physics and learning physics, measured by the Colorado Learning Attitudes Survey about Science (CLASS). Two variables—school level and gender—are examined for a series of comparative analyses. Results show that although middle school students received fewer years of education in physics, they demonstrated more expert-like conceptions about this subject matter than high school students. Also, male students in general exhibited more expert-like views than their female counterparts. While such a gender difference remained constant across both middle and high schools, for the most part it was a small-size difference.

  2. Telerobotics for dry size reduction

    International Nuclear Information System (INIS)

    Remote handling in nuclear Environmental Management (EM) programs is likely to emphasize small batch sizes in unstructured environments. Most existing robotic solutions are impractical due to cost, complexity, or reliability issues. New processes that are environmentally safe are too demanding for human operators, and require precise motion control making traditional electromechanical, hydraulic, and master/slave manipulators unacceptable. The critical missing element is a method to bridge the gap between manual operation and full automation. Rapid advances in computer technology, coupled with national laboratory research activities, has challenged PaR Systems to develop a new line of telerobotics, exploiting this technology, to enhance EM processes. Telerobotics systems permit the human operator to direct and supervise the operation of a remote robotic mechanism. The typical robotic device responds to human inputs and transfers human motion into robot motion. However, unlike teleoperation, the robotic system not only incorporates local decision making authority but can enhance input devices by; producing motion in multiple coordinate frames (e.g., base, tool, joint), automating repetitive motions, responding to real-time sensory input, and facilitating a virtual collaborative environment. The basic premise is to augment, not replace, the human operator and blend the individual abilities of each system. Humans have superior cognitive and pattern recognitive skills, while the robot is a tireless precise positioning device. To provide insight into why telerobotics is crucial to EM, this paper highlights a proposed telerobotic system for the Dry Size Reduction of contaminated components. Different design concepts, robotic control features, and networking for remote operation needed are discussed. (author)

  3. Physics: A Career for You?

    Science.gov (United States)

    American Inst. of Physics, New York, NY.

    Information is provided for students who may be interested in pursuing a career in physics. This information includes the type of work done and areas studied by physicists in the following areas: nuclear physics, solid-state physics, elementary-particle physics, atomic/molecular/electron physics, fluid/plasma physics, space/planetary physics,…

  4. Physical properties of the Uranian satellites

    Science.gov (United States)

    Brown, Robert H.; Johnson, Torrence V.; Synnott, Stephen; Anderson, John D.; Jacobson, Robert A.; Dermott, Stanley F.; Thomas, Peter C.

    1991-01-01

    Data regarding the Uranian satellites' radii, masses, mean density, and, consequently, their internal structures obtained from the Voyager encounter are analyzed. Topics covered are the sizes, shapes, topography, masses, densities, and models of the internal structures of the five major satellites. The sizes and shapes of the 10 small satellites discovered by Voyager 2 are discussed. The physical properties of the large satellites of Uranus are compared to those other satellites in the outer solar system, particularly those of Jupiter and Saturn, and the implications that these comparisons have for understanding the origin and evolution of the satellites of Uranus are discussed.

  5. O tamanho do ovo não prediz o desenvolvimento físico de avestruzes (Struthio camelus aos quinze dias de idade The size of the egg does not predict the physical development of ostriches (Struthio camelus at fifteen days old

    Directory of Open Access Journals (Sweden)

    Adriano Braga Brasileiro de Alvarenga

    2008-06-01

    Full Text Available O tamanho dos ovos está relacionado com a sobrevivência e o crescimento de filhotes de aves precociais. A inter-relação entre ovo e filhote pode ser importante para a produção animal, fornecendo subsídios para decisões estratégicas de economia, manejo e bem-estar animal. Este estudo analisou a relação entre o peso dos ovos antes da incubação e o desenvolvimento de filhotes de avestruzes (N=48 aos quinze dias de idade. Os filhotes foram criados em grupos, em berçários, com alimentação comercial e sem cuidado parental. Nos filhotes, mensurou-se o peso, a altura da cernelha e o comprimento do tarso-metatarso. Houve uma significativa diferença nos pesos dos ovos, mas as medidas corporais equivalentes dos filhotes não foram estatisticamente diferentes. Em concordância com estudos em outras espécies de aves, o peso do ovo não parece influenciar o crescimento dos filhotes de avestruzes até os 15 dias de vida, em avestruzes.The size of the eggs is related to survival and chick growth in precocial birds. The interrelationship between egg and chick development can be important for the animal production, supplying data for strategic decisions of economy, handling and animal welfare. This study analyzed the relation between the weight of the eggs and the development of ostrich chicks (N=48 at age of fifteen days old. The chicks were kept in indoor nurseries, in groups, without parental care, and fed commercial feed. It was recorded the weight, the back height and the length of the tarsus-metatarsus. There was a significant difference in the weight of the eggs, but the correspondent body chicken measures were not statistically different. In agreement to the studies in other species of birds, the weight of the egg does not seem to influence the growth of the ostriches at fifteen days old.

  6. Probabilities in physics

    CERN Document Server

    Hartmann, Stephan

    2011-01-01

    Many results of modern physics--those of quantum mechanics, for instance--come in a probabilistic guise. But what do probabilistic statements in physics mean? Are probabilities matters of objective fact and part of the furniture of the world, as objectivists think? Or do they only express ignorance or belief, as Bayesians suggest? And how are probabilistic hypotheses justified and supported by empirical evidence? Finally, what does the probabilistic nature of physics imply for our understanding of the world? This volume is the first to provide a philosophical appraisal of probabilities in all of physics. Its main aim is to make sense of probabilistic statements as they occur in the various physical theories and models and to provide a plausible epistemology and metaphysics of probabilities. The essays collected here consider statistical physics, probabilistic modelling, and quantum mechanics, and critically assess the merits and disadvantages of objectivist and subjectivist views of probabilities in these fie...

  7. Attracting girls to physics

    Science.gov (United States)

    Borg, Anne; Sui, Manling

    2013-03-01

    Large regional differences remain in the number of girls studying physics and the number of female physicists in academic positions. While many countries struggle with attracting female students to university studies in physics, climbing the academic ladder is the main challenge for these women. Furthermore, for many female physicists the working climate is not very supportive. The workshop Attracting Girls to Physics, organized as part of the 4th IUPAP International Conference on Women in Physics, South Africa 2011, addressed attitudes among education-seeking teenagers and approaches for attracting young girls to physics through successful recruitment plans, including highlighting the broad spectrum of career opportunities for those with physics qualifications. The current paper presents findings, examples of best practices, and recommendations resulting from this workshop.

  8. Basic plasma physics

    CERN Document Server

    Ghosh, Basudev

    2014-01-01

    Basic Plasma Physics is designed to serve as an introductory compact textbook for advanced undergraduate, postgraduate and research students taking plasma physics as one of their subject of study for the first time. It covers the current syllabus of plasma physics offered by the most universities and technical institutions. The book requires no background in plasma physics but only elementary knowledge of basic physics and mathematics. Emphasis has been given on the analytical approach. Topics are developed from first principle so that the students can learn through self-study. One chapter has been devoted to describe some practical aspects of plasma physics. Each chapter contains a good number of solved and unsolved problems and a variety of review questions, mostly taken from recent examination papers. Some classroom experiments described in the book will surely help students as well as instructors.

  9. Semiconductor Physical Electronics

    CERN Document Server

    Li, Sheng

    2006-01-01

    Semiconductor Physical Electronics, Second Edition, provides comprehensive coverage of fundamental semiconductor physics that is essential to an understanding of the physical and operational principles of a wide variety of semiconductor electronic and optoelectronic devices. This text presents a unified and balanced treatment of the physics, characterization, and applications of semiconductor materials and devices for physicists and material scientists who need further exposure to semiconductor and photonic devices, and for device engineers who need additional background on the underlying physical principles. This updated and revised second edition reflects advances in semicondutor technologies over the past decade, including many new semiconductor devices that have emerged and entered into the marketplace. It is suitable for graduate students in electrical engineering, materials science, physics, and chemical engineering, and as a general reference for processing and device engineers working in the semicondi...

  10. Preschoolers’ Physical Activity Behaviours

    Science.gov (United States)

    Irwin, Jennifer D.; He, Meizi; Bouck, L. Michelle Sangster; Tucker, Patricia; Pollett, Graham L.

    2016-01-01

    Objectives To understand parents’ perspectives of their preschoolers’ physical activity behaviours. Methods A maximum variation sample of 71 parents explored their preschoolers’ physical activity behaviours through 10 semi-structured focus group discussions. Results Parents perceived Canada’s Physical Activity Guidelines for Children as inadequate; that their preschoolers get and need more than 30–90 minutes of activity daily; and that physical activity habits must be established during the preschool years. Nine barriers against and facilitators toward adequate physical activity were proposed: child’s age, weather, daycare, siblings, finances, time, society and safety, parents’ impact, and child’s activity preferences. Discussion The need for education and interventions that address current barriers are essential for establishing physical activity as a lifestyle behaviour during early childhood and, consequently, helping to prevent both childhood and adulthood obesity. PMID:16625802

  11. Physics in Africa

    International Nuclear Information System (INIS)

    The paper discusses the role of basic sciences in the development of technology. This is then tied up with the broader issue of the importance of scientific and technological knowledge in the socio-economic development of a country. Physics forms the basis for most of the natural and applied sciences and technology. The state of physics in Africa is reviewed. The need for regional and international cooperation in physics education and research in Africa is stressed. (author). 13 refs, 2 tabs

  12. Physics. Module 1. Mechanics

    OpenAIRE

    Бовтрук, Алла Георгіївна; Мєняйлов, Сергій Миколайович; Максимов, Сергій Леонідович; Поліщук, Аркадій Петрович

    2009-01-01

    Ukraine’s joining Bologna process requires creating new books in physics (in English in particular). The book is developed for all forms of studying physics on the Credit-based Modular System basis in higher school. «Physics. Module 1. Mechanics» presents Newtonian mechanics and Special theory of relativity. It contains eight Study Units which include theoretical information, test questions, sample problems, laboratory works and individual home tasks. It is designed for students of engi...

  13. Physics of dance

    OpenAIRE

    Dolničar, Andreja

    2014-01-01

    In this diploma thesis three dance elements are covered from the dance as well as from the physical point of view. For every technique and performance of an individual dancing element, there are certain laws of physics, which the dancers use unconsciously. Throughout this thesis I added characteristics of physics to instructions that the dancer receives for performance of an individual dancing element. I recorded the three selected elements with a high-speed camera and using these recordings ...

  14. Advances in atomic physics

    Directory of Open Access Journals (Sweden)

    Tharwat M. El-Sherbini

    2015-09-01

    Full Text Available In this review article, important developments in the field of atomic physics are highlighted and linked to research works the author was involved in himself as a leader of the Cairo University – Atomic Physics Group. Starting from the late 1960s – when the author first engaged in research – an overview is provided of the milestones in the fascinating landscape of atomic physics.

  15. Physics in Austria

    International Nuclear Information System (INIS)

    This catalogue gives the results of an investigation on research institutes in Austria in the field of physics, including nuclear physics, which was performed by the Austrian Physical Society. The main part is on university institutes, but also other research institutes are listed. For each institute the name of the head, number of researchers, a short description of the scientific work and an overview of national and international cooperation is given. Various registers and indexes are attached. (A.N.)

  16. Action in Introductory Physics

    CERN Document Server

    McGinness, Lachlan P

    2015-01-01

    We have investigated the teaching and learning of the stationary action formulation of classical physics in a first-year university class. Instruction proceeded from the many-paths approach to quantum physics through to ray optics, classical mechanics, and relativity. Student learning and misconceptions were studied with quantitative and qualitative techniques. In particular, an action concept inventory was developed through a process of expert consultation and student feedback. Students reported action physics to be accessible, interesting and valuable.

  17. Institute of physics

    International Nuclear Information System (INIS)

    A survey is given of the personnel and activities of the Institute of Physics. Research by staff of the Nuclear Physics Group includes mainly work on heavy ion reactions and investigations of rare earth nuclei. The Elementary Particle Group has studied antineutron and antiproton annihilations, neutral current pions minus and has used the CERN ISRs. The Cosmic Physics Group has used rockets, satellite data and balloons to study the electron and proton precipitation in the upper atmosphere and magnetosphere, and aurorae. (JIW)

  18. When physical intuition fails

    OpenAIRE

    Singh, Chandralekha

    2016-01-01

    We analyze the problem solving strategies of physics professors in a case where their physical intuition fails. A non-intuitive introductory-level problem was identified and posed to twenty physics professors. The problem placed the professors in a situation often encountered by students, and their response highlights the importance of intuition and experience in problem solving. While professors had difficulty in solving the problem under the time constraint, they initially employed a system...

  19. Advances in atomic physics

    OpenAIRE

    Tharwat M. El-Sherbini

    2015-01-01

    Graphical abstract In this review article, important developments in the field of atomic physics are highlighted and linked to research works the author was involved in himself as a leader of the Cairo University – Atomic Physics Group. Starting from the late 1960s – when the author first engaged in research - an overview is provided of the milestones in the fascinating landscape of atomic physics.

  20. 3. Theoretical Physics Division

    International Nuclear Information System (INIS)

    For the period September 1980 - Aug 1981, the studies in theoretical physics divisions have been compiled under the following headings: in nuclear physics, nuclear structure, nuclear reactions and intermediate energies; in particle physics, NN and NantiN interactions, dual topological unitarization, quark model and quantum chromodynamics, classical and quantum field theories, non linear integrable equations and topological preons and Grand unified theories. A list of publications, lectures and meetings is included