Changes In Physical Conditions Research Articles

Theoretical Computation of Diffusion in Minerals and Melts

Chemical diffusion is a fundamental process in the evolution of planets. Equilibration within and among phases in response to changes in physical conditions requires the comprising chemical species to be spatially rearranged, over distances comparable to the grain size. Quantitative description of such processes demands diffusivities of these chemical species to be accurately known, while detailed insight into the mechanisms of diffusion at the atomic scale elucidate their dependence on pressure, temperature and composition. By applying our understanding of chemical bonding in condensed systems to numerically simulate diffusivity over a range of pressures and temperatures of planetary interest, we can obtain direct constraints on diffusivities at these extreme conditions, and self consistently assess the models used to extrapolate experimental data. Such computations further serve as a proving ground for testing the robustness of the various levels of theory applied in the characterization of bonding and dynamics of a material. The mathematical description of diffusion was first developed in the context of thermal transport by Fourier (1822). Its applicability to chemical transport was recognized by Fick (1855), who cast Fourier’s law of thermal conduction in terms of chemical transport and applied it to experiments on the diffusion of salt in a column of water. In an anisotropic system of n components, Fick’s description is most generally given by \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \[\frac{{\partial}\mathit{c}\_{\mathit{A}}}{{\partial}\mathit{t}} = {{\sum}\_{\mathit{i},\mathit{j}}^{3}}{{\sum}\_{\mathit{B}}^{\mathit{n} {-} 1}} {-} \mathit{D}\_{\mathit{AB}}^{\mathit{ij}}\frac{{\partial}^{2}\mathit{c}\_{\mathit{B}}}{{\partial}\mathit{x}\_{\mathit{i}}{\partial}\mathit{x}_{\mathit{j}}}\] \end{document}(1) where c A is the concentration of species A , and D AB ij is the relevant component of the diffusivity matrix (e.g., Crank 1975; Lasaga 1998; Zhang 2010). However, this description of diffusion is entirely in the continuum limit, and does not give any insight into the mechanisms by which chemical transport occurs at the atomic level. The description of chemical diffusivity was cast in an atomistic context by studies of Brownian motion (Einstein 1905; Smoluchowski …

Changes in male physiological condition during brooding activities in a natural population of a stream goby, Rhinogobius sp.

We investigated the change in physical condition of males during paternal care in a natural population of a stream goby Rhinogobius sp. LD. Hepatosomatic index (HSI) and Condition factor (K) of males guarding an egg mass were higher than those of non-breeding males. In the first brooding cycle, the HSI of males decreased with the progress of embryo development. Moreover, in the second brooding cycle, both the HSI and K decreased, suggesting that the energy reserves in the somatic tissue were used when the liver reserves were exhausted as a source of energy for paternal activities. After paternal care, males showed reduced K and were unable to recover HSI immediately. Comparisons of the physical condition between non-guarding males after the first brooding cycle and males guarding an early stage clutch in the second brooding cycle indicated that males which could recover HSI and K were able to have a second brooding cycle. This suggested that the physical condition determines participation in breeding activity and the number of brooding cycles, greatly influencing male reproductive success.

The impact of age on the ability to perform under pressure: golfers on the PGA tour

This paper is about aging and the ability to perform under pressure on the PGA tour. Performance increases with golfing skill, but may first increase and then decrease with age as experience interacts with changes in physical condition. Similarly, mental fortitude or the ability of a golfer to perform under pressure may first increase and then decrease with age as experience interacts with changes in the ability to concentrate. Net performance on the tour is the result of both physical golfing skill and the ability to perform under pressure. We control for changes in physical skill and focus on the mental side of the game. The role of experience suggests an inverted U shaped relationship between age and mental performance that could vary significantly across golfers. We use Order-m FDH to calculate a measure of performance under pressure, and we confirm an inverted U-shaped curve with age. Along the way, we examine the ability to perform under pressure at the level of the individual golfer.

Intranight polarization variability in radio-loud and radio-quiet AGN

(Abriged) Intranight polarization variability in AGN has not been studied extensively so far. Studying the variability in polarization makes it possibly to distinguish between different emission mechanisms. Thus it can help answering the question if intranight variability in radio-loud and radio-quiet AGN is of the same or of fundamentally different origin. In this paper we investigate intranight polarization variability in AGN. Our sample consists of 28 AGN at low to moderate redshifts (0.048 < z < 1.036), 12 of which are radio-quiet quasars (RQQs) and 16 are radio-loud blazars. The subsample of blazars consists of eight flat-spectrum radio-quasars (FSRQs) and eight BL Lac objects. We find clear differences between the two samples. A majority of the radio-loud AGN show moderate to high degrees of polarization, more than half of them also show variability in polarization. There seems to be a dividing line for polarization intranight variability at P~5 per cent over which all objects vary in polarization. Only two out of 12 radio-quiet quasars show polarized emission, both at levels of P<1 per cent. The lack of polarization intranight variability in radio-quiet AGN points towards accretion instabilities being the cause for intranight flux variability whereas the high duty cycle of polarization variability in radio-loud objects is more likely caused by instabilities in the jet or changes of physical conditions in the jet plasma.

Transboundary water vulnerability and its drivers in China

Competitive use of transboundary freshwater resources is becoming one of the key factors influencing regional peace and political relationship among states. In China, 18 major international river basins are concentrated in three regions, of which the total annual outflow at the border is 7320×108 m3, occupying 26.8% of the total annual runoff of China, and the inflow at the border is only 172×108 m3. In this paper, we analyzed the major drivers affecting shared water vulnerability in China, namely: (1) changes in physical conditions affecting the availability of water; (2) competing objectives between economic development and ecological conservation; (3) lack of emergency response mechanisms; (4) unsound administrative institutions; and (5) shortcomings in the development of regional cooperation based on transboundary waters. We concluded by identifying four pathways for reducing vulnerability: (1) encouraging scientific research cooperation; (2) constructing information-sharing channels; (3) establishing early-warning mechanisms; and (4) promoting further coordination and negotiation.

How to evaluate body conditions of red deer (Cervus elaphus) in an alpine environment?

The aim of this investigation was to compare different indices for evaluating nutritional conditions of red deer (Cervus elaphus) in an alpine environment during the autumn in order to detect the most convenient ones for management purposes in our specific situation. Body conditions of 274 red deer were evaluated using kidney fat index, back fat index and body condition scores. Body Condition Scores was the easiest but the least reliable method. Both kidney fat index and back fat index were significantly affected by age and sex class (always lower in younger animals) and, in females, also by lactation status. In stags, a negative regression effect of culling date on both kidney fat index and back fat index was observed. A significant positive correlation between kidney fat index and back fat index was recorded. Both kidney fat index and back fat index were objective indicators of nutritional status and sensitive to changes in physical conditions, but back fat index was both quicker and easier to be measured. As a direct implication, we suggest that back fat index can be a practical and reliable indicator for monitoring red deer conditions in alpine areas during the autumn, provided that the effects of sex, age and date of culling are taken into account.

Artificial vocal folds adjustments to a patient’s voice as easily as changing hearing aids or eyeglasses

For anti-ageing, devices and procedures to improve hearing (hearing aids, cochlear implants, etc.) and vision (eyeglass, intra ocular lens, etc.) are well established as communication support tools for the "speech chain". They can be fit to a person's individual needs, and adjusted as these needs change. However effective tools to improve voice problems associated with physiological aging are not so well established. Review previous phono surgical techniques with my experience, I propose a complete different approach for glottal incompetence. I suggest a new adjustable surgical technique as a replacement for previous injection techniques used to treat glottal incompetence. My proposed solution is to implant an inflatable bag, or balloon, on the lateral side of the vocal fold. Unlike Autologous transplantation of fascia into the vocal folds procedures, where the implanted material appears to become vocal-fold tissue, the new implant would function as an artificial vocal fold. Using the proposed technique, the degree of augmentation can be adjusted to meet changing physical conditions.

Are the vegetation structure and composition of the shrubby Caatinga free from edge influence?

Edge influence, or edge effect, drives many biological changes in fragmented landscapes. This has been extensively studied in many forest ecosystems, but it remains to be described for the Brazilian Caatinga. Based on the biotic and physical conditions of the shrubby Caatinga, our prediction a priori was that this type of vegetation is free from edge influence in terms of vegetation structure and composition. We sampled shrubs, cacti and trees in twenty 200 m² plots on old edges (&gt;60 yrs old) and interior of a 690 ha fragment, partially isolated and surrounded by Opuntia ficus-indica cacti. Plant height, stem diameter at ground level, stem density, species richness and diversity were statistically equal between edge and interior habitats. Magnitude of edge influence varied from -0.027 to 0.027, indicating low ecological importance of edge creation for the measured variables. Additionally, floristic similarity between habitats was 90% and a principal component analysis showed that species composition varied in a similar manner at edges and interiors. These results indicate that the vegetation of the sampled fragment is not ecologically affected by the creation of edges and suggests that changes in physical conditions and resource availability after edge creation are not enough to eliminate established plants or to alter recruitment and survival of new individuals.

In situultra-small-angle X-ray scattering study of the solution-mediated formation and growth of nanocrystalline ceria

Results are presented for anin situsynchrotron-based ultra-small-angle X-ray scattering (USAXS) study of the solution-mediated formation and growth of nanocrystalline ceria (n-CeO2) using a new remote-controlled, isothermal, circulating fluid flow cell. The fluid flow mitigates or reduces X-ray beam-induced damage, air bubbles or particulate flocculation within the bulk solution, but prevents any coarse particulates that do form from settling out from suspension. Combined with the large-scale range accessible in USAXS studies, the flow cell has enabled measurement,in situand in real time, of structural characteristics from 10 Å to a few micrometres in size as a function of the changing physical and chemical conditions. By applying a multi-component model, the nanoparticle formation and growth component has been identified. Control and online monitoring of flow rate, temperature and pH suspension conditions have permitted real-time studies of the formation and growth of the individual n-CeO2particles from homogeneous dilute solution over several hours. Aspects of the nanoparticle nucleation and growth are revealed that have not been observed directly in measurements on this system.

Temporal changes of physical conditions in the photospheric layers of a solar flare

An M4.1/1B solar flare on November 5, 2004, is investigated. The Stokes I ± V profiles of nine photospheric Fe I, Fe II, Sc II, and Cr II lines are studied for three instants of this flare (11 h 35 m , 11 h 39 m , and 11 h 45 m UT). The magnetic fields in the flare were measured in two ways: using the center-of-gravity method and by comparing the observed profiles with the theoretical ones computed with Baranovsky’s code. Analysis of the profiles reveals that the magnetic field strength peaked in the upper photosphere (logτ500 = −2.7) at the flare maximum (11 h 35 m ); this peak was smeared and shifted into the deeper photospheric layers as the flare evolved. The semiempirical model of the flare has two layers with an enhanced temperature: in the upper and middle photosphere. These layers also shifted deep into the photosphere as the flare evolved. The turbulent velocities at the distribution maximum increased by almost a factor of 5 compared to those in the undisturbed photosphere, while the plasma density both increased and decreased by a factor of 3–6.

Exercise and Self-Esteem in Menopausal Women: A Randomized Controlled Trial Involving Walking and Yoga

To examine the effects of walking and yoga on multidimensional self-esteem and roles played by self-efficacy, body composition, and physical activity (PA) in changes in esteem. Four-month randomized controlled exercise trial with three arms: walking, yoga, and control. Previously low-active middle-aged women (n=164; M age = 49.9; SD = 3.6). Structured and supervised walking program meeting three times per week for I hour and supervised yoga program meeting twice per week for 90 minutes. Body composition, fitness assessment, and battery of psychologic measures. Panel analysis within a structural equation modeling framework using Mplus 3.0. The walking and yoga interventions failed to enhance global or physical self-esteem but improved subdomain esteem relative to physical condition and strength (for walking) and body attractiveness (for both walking and yoga). Over time the effects of PA, self-efficacy, and body fat on changes in physical self-esteem and global esteem were mediated by changes in physical condition and body attractiveness subdomain esteem. Women reporting greater levels of self-efficacy and PA with lower body fat also reported greater enhancements in subdomain esteem. These results provide support for the hierarchic and multidimensional nature of self-esteem and indicate that middle-aged women may enhance certain aspects of physical self-esteem by participating in PA.

Reflectance and transmittance of TrueFormTM powder and its composites to CO2 laser

PurposeThe purpose of this paper is to report on a study of the effect of glass microsphere (GMS) and potassium bromide (KBr) powder as an additive on the reflectance and transmittance of TrueFormTM acrylic‐styrene co‐polymer (TF) powder to CO2 laser during selective laser sintering (SLS).Design/methodology/approachGMSs and KBr powder were chosen because glass is opaque to CO2 laser while KBr is transparent. The GMSs were treated with silane coupling agent and hydrofluoric acid to study the surface effect on the optical properties of TF/GMS blends. KBr powder was blend with TF powder in an attempt to modify the penetration depth of the laser in the powder bed. An integrating sphere was used to measure the reflectance of the powder bed. In the measurement of transmittance, a power meter was placed below the powder layer, which was supported by a KCl disc, to register the transmitted laser energy through the powder layer.FindingsFor the TF/GMS blends, smaller GMSs gave a higher reflectance while the surface treatments had little effect. The transmittance of both the polymer and the blends were very low. Although bulk KBr is highly transparent to CO2 laser, adding 30 vol% of KBr powder to TF hardly increased the transmittance of the powder bed.Research limitations/implicationsExperiments were carried out on a modified laser engraving machine rather than a commercial SLS machine. The laser energy density used was lower than that for normal SLS processes and no significant changes of physical condition of the powder bed were inflicted. The results only indicate the optical properties in the initial state.Practical implicationsThe effects of transparent and non‐transparent fillers on the optical properties of the powder bed are presented.Originality/valueThis work furthers the understanding of heat absorption behavior of the powder bed during SLS.

Effects of turbulent diffusion on the chemistry of diffuse clouds

Aims. We probe the effect of turbulent diffusion on the chemistry at the interface between a cold neutral medium (CNM) cloudlet and the warm neutral medium (WNM). Methods. We perform moving grid, multifluid, 1D, hydrodynamical simulations with chemistry including thermal and chemical diffusion. The diffusion coefficients are enhanced to account for turbulent diffusion. We post-process the steady-states of our simulations with a crude model of radiative transfer to compute line profiles. Results. Turbulent diffusion spreads out the transition region between the CNM and the WNM. We find that the CNM slightly expands and heats up: its CH and H2 content decreases due to the lower density. The change of physical conditions and diffusive transport increase the H + content in the CNM which results in increased OH and H2O. Diffusion transports some CO out of the CNM. It also brings H2 into contact with the warm gas with enhanced production of CH + ,H + ,O H and H 2O at the interface. O lines are sensitive to the spread of the thermal profile in the intermediate region between the CNM and the WNM. Enhanced molecular content at the interface of the cloud broadens the molecular line profiles and helps exciting transitions of intermediate energy. The relative molecular yields are found higher for bigger clouds. Conclusions. Turbulent diffusion can be the source of additional molecular production and should be included in chemical models of the interstellar medium (ISM). It also is a good candidate for the interpretation of observational problems such as warm H2 ,C H + formation and presence of H + .

Algorithm to detect abnormal states of elderly persons for home monitoring

AbstractWith the advance of an elderly‐dominated society, the population of elderly persons who live alone is increasing. To allow health checking of the solitary elderly when at home, it is planned to install sensors in houses for long‐term monitoring. The purpose of this is to detect abnormal states of solitary elderly persons in daily life (such as staying immobile due to bad physical condition or inability to move as a result of falling or sudden change of physical condition). An algorithm was developed to detect abnormal states of the subject (an elderly person) by using data on the operating times of various sensors installed in an actual home. An algorithm based on the simple logical operation of ORing all sensor output signals is considered, following the idea that the sensors will not respond for a long time if an abnormality occurs in the subject. The effect of the setting of the no‐response time of the sensors on the detection rate is investigated. It is concluded that abnormalities can be satisfactorily detected, if a sensor response is absent for 2 hours and 15 minutes. © 2007 Wiley Periodicals, Inc. Syst Comp Jpn, 38(6): 34–42, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20411 Copyright © 2004 Wiley Periodicals, Inc.

Integrated analyses of litho- and biofacies in a Pliocene cyclothemic, alluvial to shallow marine succession (Tuscany, Italy)

Lithofacies analysis of the upper part of the Pliocene succession of the Valdelsa basin (central Italy) unravelled a number of depositional environments, ranging from alluvial plain to coastal, to marine. Strata are arranged in a hierarchy of elementary and composite unconformity-bounded units. A palaeoecological study of macro- (molluscs) and microfossils (pollen, dinocysts, foraminifera) allowed to finely reconstruct sub-environments within fine-grained terrestrial, coastal and marine deposits and thence to track the spatial and temporal change of physical conditions. The stacking pattern of sedimentary units highlights the lateral switching of onshore-offshore gradients and documents relative sea-level changes. These units are interpreted in a sequence stratigraphic framework. Elementary depositional sequences are arranged to form six composite depositional sequences, in turn encased within two major synthems. This hierarchy of unconformity-bounded sedimentary units suggests that sea-level variation has occurred at different time-frequencies. Glacio-eustasy and active tectonism are discussed as the main forcing factors regulating the different scales of sedimentary cyclicity.

強度を自己選択した有酸素性運動中における生理的要因の経時変化と自覚的運動強度との相互関係

In recent years, a self-selected exercise intensity (SSEI) method and its protocol consisting of 5-min fixed-load cycling at 70% of maximal oxygen uptake followed by 15-min SSEI cycling (SSFL70%) has been accepted as an intensity regulation method for better exercise prescription. The method simplifies exercise prescription and contributes to exercise habituation. There were no significant differences in ratings of perceived exertion (RPE) during exercise between the SSEI method and SSFL70%. However, the percentage of maximal load (%loadmax) regulated by each method differed significantly. These results suggest that the regulated intensity is not based on RPE in either or both of the two methods. In the present study, the interrelation between RPE and the values of physiological variables, and between RPE and the exercise load during the SSEI method and SSFL70% was examined chronologically. Thirty-six healthy men (aged 25.3±2.7 years, mean±SD) performed two trials consisting of 20-min cycling exercise using both the SSEI method and SSFL70% protocols. The coefficient of cross-correlation between FECO2 and RPE for cardiorespiratory function calculated during exercise was higher for the SSEI method than for SSFL70%. The tendency for the higher cross-correlation in the SSEI method was ascertained from the RPE value for the femoral region and %loadmax. However, the time cycle of positive to negative changes in the coefficients of cross-correlation was relatively shorter for SSFL70% than for the SSEI method. These results suggest that changes in physical condition and workload during exercise using SSFL70% are reflected in RPE in the short term compared with the SSEI method.

Assessment of higher insect taxa as bioindicators for different logging‐disturbance regimes in lowland tropical rain forest in Sabah, Malaysia

AbstractOne of the serious environmental problems since the 1980s has been the conflict between the high rate of deforestation and maintenance of healthy ecosystem services and biological values in tropical forests. There is an urgent demand for setting up an appropriate environmental assessment to keep healthy ecosystem functions and biodiversity along with sustainable forest use based on ecology. In this study, we tried to assess logging‐disturbance effects on the abundances of several flying insect groups (higher‐taxon approach) in lowland tropical rain forest (Deramakot Forest Reserve, Sabah, Malaysia), while considering seasonal changes and vertical forest stratification. The season was the most important factor affecting the abundances of all the insect groups. Effects of logging disturbance were prominent in the understorey but obscure in the canopy. Changes in physical conditions caused by logging—possibly an increased evaporation due to solar radiation—may have decreased the abundance of desiccation‐sensitive insects, especially in the understorey. There are also two probable reasons for the difference between events in the understorey and those in the canopy: (1) noise effects of various physical, environmental factors may have obscured insect responses to logging disturbance in the canopy; (2) higher spatio‐temporal variation in quality and quantity of living food resources—such as leaves, flowers and fruits—provided in the canopy may have affected the abundance of their consumer insects independently of logging disturbance. Thus, this study suggests that the abundance of some insect groups at higher‐taxon level, especially in the understorey, can be used as bioindicators for assessing effects of logging disturbance on the forest ecosystem.

Observational characteristics and association of umbral oscillations and running penumbral waves

Context. Umbral flashes (UFs) and running penumbral (RP) waves are believed to be closely related oscillatory phenomena of sunspots. Aims. We investigate the association of UFs and RP waves to see whether the latter are a visual pattern created by a common source with UFs or a trans-sunspot wave driven by UFs. Methods. Simultaneous, two-dimensional, dual-line observations in $\ion{Ca}{ii}$ 8542 A and ${\rm H\alpha}$ 6563 A, obtained with the Multichannel Subtractive Double Pass (MSDP) spectrograph mounted on the German VTT at Teide Observatory on Tenerife, are used for this study. High-cadence 8 s Doppler velocity images, spectrograms, and spectral-analysis results are used to study the characteristics and the relationship of UFs and RP waves. Results. Several UFs were observed that seem to fill the whole umbra. Doppler velocity variations with time indicate a shock behaviour for UFs, as well as for umbral and RP waves and a smooth continuous propagation of the latter from the umbra through the umbra-penumbra boundary out to the edge of the penumbra. Furthermore, the spectral analysis shows a decreasing oscillatory frequency as we move from the umbra outwards and a jump at the umbra–penumbra boundary that could possibly reflect, apart from a change in physical conditions, a drastic change of the magnetic field inclination with respect to the vertical. Conclusions. The results do not permit us to convincingly support one scenario over the other (i.e. visual pattern vs. trans-sunspot wave) for RP waves; however, they do provide important constraints for future models of sunspot oscillations and RP waves.

Crystallization of orbicular rocks exemplified by the Slättemossa occurrence, southeastern Sweden

The orbicular rock at Slättemossa, southeastern Sweden, has a quartz monzodioritic composition. The cores of the orbicules crystallized directly from the orbicule-forming magma; cores made up of xenoliths have not been observed. Outside the core follow first an inner mafic, a felsic and then an outer mafic shell. The orbicules occur in a matrix, which is similar to the core. They grew simultaneously and show an almost perfect parallelism in evolution. After initial ‘normal’ crystall-ization of the magma, superheating probably triggered by a sudden addition of volatiles destroyed earlier formed nuclei and also affected the already crystallized part of the rock. Cooling caused heterogeneous nucleation and rapid crystallization, which formed the inner mafic shell. This is enriched in mafic minerals, especially biotite, compared to the core. At the same time the grain size becomes significantly smaller. Depletion in mafic components, possibly intensified by a sudden change in physical conditions, destabilized biotite and amphibole crystallization, causing oversaturation in plagioclase components, forming a felsic shell having a sharp boundary with the mafic shell. Plagioclase is extremely altered. Mafic minerals were then stabilized, probably due to depletion of plagioclase components, and an outer mafic shell formed. With the return to homogeneous nucleation, matrix formation concluded the crystallization. Orbicules might have moved in the magma causing some squeezing of magma surrounding the orbicules, but major movements involved the settling of the whole package of orbicules and matrix in the surrounding non-orbicular magma.

Objective and subjective stressors and the psychological adjustment of melanoma survivors

This study of 300 melanoma survivors examines the relative contributions of objective illness-related factors (stage of illness at diagnosis, time since diagnosis, and change in physical condition) and of subjective factors (cognitive appraisal) to their psychological adjustment. The findings show that lower appraisal of their situation as a threat, higher appraisal of it as a challenge, and higher appraisal of their subjective ability to cope with it all increased their well-being, while lower threat appraisal and higher appraisal of subjective ability to cope also reduced their distress. These findings, which are consistent with Lazarus and Folkman's stress coping theory, suggest that subjective factors may be more important than objective medical factors in predicting patients' adjustment. With this, more advanced stage at diagnosis contributed to reducing distress, while being married contributed both to higher well-being and reduced distress.