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Increasing Values (increasing + value)
Selected AbstractsEffects of linear, ambient wind shear on simulated mammatus-like cloudsATMOSPHERIC SCIENCE LETTERS, Issue 4 2009Katharine M. Kanak Abstract A suite of numerical experiments is conducted to extend our previous studies to explore the effects of linear, ambient wind shear on simulated mammatus-like clouds. Increasing values of unidirectional shear result in banded cloud bases, and for the strongest shears roll-type quasi-two-dimensional convection results rather than three-dimensional lobe morphology. Two observed soundings were used, and the sounding with a drier, shallower sub-cloud layer appeared to be most strongly affected by the presence of the ambient shear. The drier sounding also had less snow in the mammatus lobes owing to sublimation. Copyright © 2009 Royal Meteorological Society [source] Bond rolling resistance and its effect on yielding of bonded granulates by DEM analysesINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 8 2006M. J. Jiang Abstract A discrete element modelling of bonded granulates and investigation on the bond effect on their behaviour are very important to geomechanics. This paper presents a two-dimensional (2-D) discrete element theory for bonded granulates with bond rolling resistance and provides a numerical investigation into the effect of bond rolling resistance on the yielding of bonded granulates. The model consists of mechanical contact models and equations governing the motion of bonded particles. The key point of the theory is that the assumption in the original bond contact model previously proposed by the authors (55th CSCE-ASCE Conference, Hamilton, Ont., Canada, 2002; 313,320; J. Eng. Mech. (ASCE) 2005; 131(11):1209,1213) that bonded particles are in contact at discrete points, is here replaced by a more reliable assumption that bonded particles are in contact over a width. By making the idealization that the bond contact width is continuously distributed with the normal/tangential basic elements (BE) (each BE is composed of spring, dashpot, bond, slider or divider), we establish a bond rolling contact model together with bond normal/tangential contact models, and also relate the governing equations to local equilibrium. Only one physical parameter , needs to be introduced in the theory in comparison to the original bond discrete element model. The model has been implemented into a 2-D distinct element method code, NS2D. Using the NS2D, a total of 86 1-D, constant stress ratio, and biaxial compressions tests have been carried out on the bonded granular samples of different densities, bonding strengths and rolling resistances. The numerical results show that: (i) the new theory predicts a larger internal friction angle, a larger yielding stress, more brittle behaviour and larger final broken contact ratio than the original bond model; (ii) the yielding stress increases nonlinearly with the increasing value of ,, and (iii) the first-yield curve (initiation of bond breakage), which define a zone of none bond breakage and which shape and size are affected by the material density, is amplified by the bond rolling resistance in analogous to that predicted by the original bond model. Copyright © 2006 John Wiley & Sons, Ltd. [source] Effects of surfactant and molecular weight of polyol on grating formation and switching of holographic PDLCPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 11 2008S. S. Shim Abstract The interposition of surfactants between polymer and liquid crystal (LC) droplets was theoretically predicted by the positive spreading coefficient (0,<,,31) and utilized to interpret the morphology, grating formation kinetics, diffraction efficiency, and switching of the holographic polymer dispersed liquid crystal (HPDLC), prepared from various types (octanoic acid, poly oxyethylene octyl phenyl ether, and perfluoro-1-butanesulfonyl fluoride) and amounts (0,9 wt%) of surfactant and molecular weights of polyol (PPG). Regardless of the surfactant type, diffraction efficiency increased with the addition and increasing amount of surfactant, a tendency consistent with increasing value of spreading coefficient, which is determined by the formulations of grating formation. In contrast, diffraction efficiency showed a maximum with the polypropylene glycol (PPG) molecular weight. Surfactant effectively reduced the anchoring energy and electrically drove the film which otherwise was not driven. Overall, surfactant with greater ,31 gave smaller droplet, greater diffraction efficiency, driving voltage, contrast ratio, and smaller response time. Copyright © 2008 John Wiley & Sons, Ltd. [source] Relationship of glucose concentrations with PAI-1 and t-PA in subjects with normal glucose toleranceDIABETIC MEDICINE, Issue 8 2006P. E. Heldgaard Abstract Aims To study metabolic risk factors for the development of cardiovascular disease (CVD), including markers of the fibrinolytic system in relation to blood glucose levels in subjects with normal glucose tolerance and fasting blood glucose levels below 5.6 mmol/l. Methods Cross-sectional, community-based study from a primary health-care centre of adult subjects with normal glucose tolerance. Analysis of fasting and 2-h post-load blood glucose concentrations were centralized and related to anthropometric characteristics, metabolic variables, inflammatory markers, and coagulation and fibrinolytic variables. Results Increasing fasting blood glucose concentrations within the normal range in subjects with normal glucose tolerance were associated with increasing age, body mass index, and waist circumference, and with increasing concentrations of metabolic risk factors for development of CVD. After adjustment for gender, age, body mass index (BMI), and fasting insulin, levels of plasmin activator inhibitor (PAI-1) and tissue type plasminogen activator (t-PA) increased significantly with increasing levels of fasting glucose within the normal range (P = 0.012 and P < 0.0001, respectively). Conclusions We found risk factors for CVD, specifically key components of the fibrinolytic system, PAI-1 and t-PA, increased with increasing fasting glucose levels even in subjects with normal glucose tolerance. This observation may help to explain the increased risk of CVD with increasing values of fasting glucose in the normal range. [source] Impact of body fat mass extent on cardiac autonomic alterations in womenEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 8 2009J. Sztajzel Abstract Background, Obesity has been associated with significant abnormalities of the cardiac autonomic regulation. However, the precise impact of increasing body weight on cardiac autonomic function and the metabolic and hormonal contributors to these changes are presently unclear. The aim of our study was to explore in subjects with increasing values of body mass index (BMI) the alterations of cardiac autonomic function and to establish the potential role of various metabolic and hormonal contributors to these alterations. Materials and methods, We investigated time and frequency domain heart rate variability (HRV) parameters taken from 24-h Holter recordings, and several anthropometric, metabolic and hormonal parameters (plasma glucose, insulin, triglycerides, free fatty acids, leptin and adiponectin) in 68 normoglycaemic and normotensive women (mean age of 40 ± 3 years), subdivided according to their BMI into 15 normal body weight (controls), 15 overweight, 18 obese and 20 morbidly obese. Results, Heart rate was increased and HRV was decreased in the morbidly obese group as compared with controls. In overall population, a negative association linked body fat mass (FM) to HRV indices. None of the metabolic and hormonal parameters were significantly related to the HRV indices, after they were adjusted for the body FM. Conclusions, Morbidly obese, normoglycaemic and normotensive young women have increased HR and low HRV, indicating an abnormal cardiac autonomic function and representing a risk factor for adverse cardiovascular events. A decrease of HRV parameters is associated with a progressive increase of body FM. Other metabolic and hormonal factors, characterising obesity, do not show an independent influence on these HRV alterations. [source] Incorporating Penalty Function to Reduce Spill in Stochastic Dynamic Programming Based Reservoir Operation of Hydropower PlantsIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 5 2010Deependra Kumar Jha Non-member Abstract This paper proposes a framework that includes a penalty function incorporated stochastic dynamic programming (SDP) model in order to derive the operation policy of the reservoir of a hydropower plant, with an aim to reduce the amount of spill during operation of the reservoir. SDP models with various inflow process assumptions (independent and Markov-I) are developed and executed in order to derive the reservoir operation policies for the case study of a storage type hydropower plant located in Japan. The policy thus determined consists of target storage levels (end-of-period storage levels) for each combination of the beginning-of-period storage levels and the inflow states of the current period. A penalty function is incorporated in the classical SDP model with objective function that maximizes annual energy generation through operation of the reservoir. Due to the inclusion of the penalty function, operation policy of the reservoir changes in a way that ensures reduced spill. Simulations are carried out to identify reservoir storage guide curves based on the derived operation policies. Reservoir storage guide curves for different values of the coefficient of penalty function , are plotted for a study horizon of 64 years, and the corresponding average annual spill values are compared. It is observed that, with increasing values of ,, the average annual spill decreases; however, the simulated average annual energy value is marginally reduced. The average annual energy generation can be checked vis-à-vis the average annual spill reduction, and the optimal value of , can be identified based on the cost functions associated with energy and spill. © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Composition and organoleptic characteristics of oil from Arbequina olive (Olea europaea L) trees under deficit irrigationJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2002J Tovar Abstract This study evaluated the effects of different regulated deficit irrigation (RDI) strategies applied to olive (Arbequina cultivar) trees on the qualitative and quantitative parameters of the resulting oil during the maximum evaporative demand period for three consecutive crop seasons. Quality indices, fatty acid composition, pigments, colour, ,-tocopherol and phenolic contents, bitter index, oxidative stability and organoleptic properties of the oil were determined. Irrigation did not affect those parameters used as criteria for classifying olive oil in its commercial grades. Only polyphenol and o -diphenol contents and, consequently, the bitter index and oxidative stability were affected by the RDI strategy, with increasing values as the water applied decreased. Regulated deficit irrigation resulted in important savings in irrigation requirements without detriment to oil quality. © 2002 Society of Chemical Industry [source] Effects of quenched disorder on Griffiths phase and EPR line width in La0.67,2xNd2xCa0.33,xSrx MnO3 manganitesPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 4 2008O. A. Yassin Abstract It is widely accepted that there is Griffiths phase (GP) present in the paramagnetic phase in doped manganites. We studied the effect of quenched disorder on the region of GP in connection with the temperature dependence of the line width (,H) of the electron paramagnetic resonance (EPR) in La0.67,2xNd2xCa0.33,xSrx MnO3 (x = 0, 0.1, 0.15, 0.2 and 0.25). With this approach it is found that ,H (T), the minimum in the line width (,Hmin) and Tmin are reproduced. With increasing values of the quenched disorder the values of ,Hmin are found to increase. A numerical relation that correlates the temperature range in which GP exists and the cation size disorder is obtained and found to be in agreement with some reported data. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The bone,metal interface of defect and press-fit ingrowth of microwave plasma-chemical vapor deposition implants in the rabbit modelCLINICAL ORAL IMPLANTS RESEARCH, Issue 1 2005Stephan Rupprecht Abstract Purpose: The histological differences between the defect and contact areas of the implant surface to bone were tested in 35 New Zealand White rabbits in a standardized model. Microwave plasma chemical vapor-coated implant probes were tested in control and uncoated materials. Material and methods:, In each femur of 35 rabbits, cylindrical implant rods with a planed side were inserted. Three groups, divided in coated and uncoated material at half, were observed 42, 84 and 168 days. The probes were examined histologically for bone,implant contact in the curved and plane (defect area) sides. Results: Generally the bone,implant contact seems to be nearly constant in time in the curved area of coated and uncoated probes. Here the implant was inserted in the press-fit mode. Diamond-coated probes showed similar bone,implant contact (51.9% (42 days), 62.5% (84 days), 56.1% (168 days)) compared to uncoated material (56.2%, 65.4%, 62.9%). The defect area (plane side) had no bone,implant contact at the time of insertion and showed increasing values on longer observation times with only significant differences in the 42-day group between coated (17.85%, 35.2%, 47.7%) and uncoated materials (35.5%, 40.55%, 51.81%). Conclusion: The evaluation of the curved side of the implant probe showed no great variation of bone,implant contact within the described observation times. This model simulates the usual implant insertion situation. The diamond-coated material becomes osseointegrated at a later time point. The bone,implant contact was only statistically relevant in one group in comparison to uncoated material. Résumé Les différences histologiques entre la lésion et les aires de contact de la surface implantaire à l'os ont été testées chez 35 lapins blancs de Nouvelle-Zélande dans un modèle standardisé. Des sondes implantaires recouvertes d'une vapeur chimique de plasma par micro-ondes ont été testées par rapport à du matériel non-recouvert. Dans chaque fémur des 35 lapins, des baguettes implantaires cylindriques avec un côté plat ont été insérées. Trois groupes, divisés en matériel couvert et non-couvert à moitié ont été observés après 42, 84 et 168 jours. Les sondes ont été examinées histologiquement pour le contact os-implant dans les sites courbe et plat (aire de la lésion). Généralement le contact os-implant semblait constant dans la durée dans la zone courbe des sondes couvertes et non-couvertes. Ici l'implant a été inséré par la méthode de pressé-fixé (=fit après insertion). Les sondes recouvertes de diamant montraient un contact os-implant semblable (52%à 42 J, 63%à 84 J et 56%à 168 J) comparées au matériel non-recouvert (56%, 65%, 63%). L'aire de la lésion (partie plate) n'avait pas de contact os-implant au moment de l'insertion et montrait des valeurs grandissantes avec le temps avec seulement des différences significatives dans les groupes à 42 jours entre le matériel recouvert (18%, 35% et 48%) et le non-recouvert (36%, 41% et 52%). L'évaluation du côté arrondi de la sonde implantaire ne montrait pas de grande variation dans le contact os-implant dans les temps d'observation décrits. Ce modèle simule la situation d'insertion implantaire usuelle. Le matériel recouvert de diamant devient ostéoïntégré plus tardivement. Le contact os-implant n'était statistiquement valable que dans un groupe en comparaison avec le matériel non-recouvert. Zusammenfassung Ziel: Mit einem standartisierten Modell untersuchte man an 35 weissen New Zealand Kaninchen die histologischen Unterschiede zwischen in direktem Kontakt mit dem Implantat stehendem Knochen und Defektstellen. Testimplantate, die mit Diamant beschichtet worden sind, verglich man mit unbeschichtetem Material als Kontrolle. Material und Methode: In jeden Femur der 35 Kaninchen inserierte man zylindrische Implantate, die auf einer Seite abgeplattet waren. Man beobachtete drei Gruppen, je hälftig unterteilt in beschichtete und unbeschichtete Implantate, während 42, 84 und 168 Tagen. Die Blockbiopsien wurden in der runden und abgeflachten (Defektzone) Region histologisch auf ihren Implantat-Knochen-Kontakt hin untersucht. Resultate: Allgemein stellte man fest, dass der Knochen-Implantat-Kontakt während der ganzen Beobachtungszeit in der runden Region der beschichteten und unbeschichteten Implantate ziemlich konstant zu bleiben scheint. Die Implantate sind eingeklopft worden. Die diamantbeschichteten Prüfkörper zeigten einen ähnlichen Knochen-Implantat-Kontakt (51.9% (42d), 62.5% (84d), 56.1% (168d)) wie die unbeschichteten Prüfkörper (56.2%, 65.4%, 62.9%). Die Defektzonen (abgeflechte Stellen) hatten zum Zeitpunkt der Implantation natürlich keinen Kontakt zum Knochen, zeigten aber während der Beobachtungszeit zunehmend Kontakt. Einzig nach 42 Tagen zeigten sich zwischen den beschichteten (17.85%, 35.2%, 47.7%) und den unbeschichteten Implantaten (35.5%, 40.55%, 51.81%) signifikante Unterschiede. Zusammenfassung: Innerhalb der umschriebenen Beobachtungszeit zeigte die Untersuchung der runden Seite der Implantate keine grossen Unterschiede bei der Ausdehnung der Kontaktflächen zum Knochen. Dieses Modell empfindet die übliche Implantationssituation nach. Das mit Diamant beschichtete Material wird zu einem etwas späteren Zeitpunkt osseointegriert. Die Unterschiede im Knochen-Implantat-Kontakt waren im Vergleich mit dem unbeschichteten Material nur in einer Gruppe statistisch gesehen von Bedeutung. Resumen Propósito: Se probaron las diferencias histológicas entre los defectos y las áreas de contacto de la superficie del implante al hueso en 35 conejos blancos de Nueva Zelanda en un modelo estandarizado. Se investigaron implantes de prueba cubiertos de plasma de vapor químico de microonda frente a material sin cubierta como control. Material y Métodos: Se insertaron en cada fémur de 35 conejos barras cilíndricas de implantes con un lado plano. Se observaron tres grupos divididos en material cubierto y no cubierto a la mitad durante 42, 84 y 168 días. Las pruebas se examinaron histológicamente para contacto hueso-implante en los lados curvado y plano (área de defecto). Resultados: Generalmente el contacto hueso implante suele ser constante en el tiempo en el área curvada de las pruebas cubiertas y no cubiertas. Aquí el implante se insertó en el modo press-fit. Las pruebas cubiertas de diamantes mostraron un contacto hueso implante similar (51.9% (42d), 62.5% (84d), 56.1% (168)) comparados con el material no cubierto (56.2%, 65.4%, 62.9%). El área de defecto (lado plano) no tuvo contacto hueso implante en el momento de la inserción y mostró valores crecientes en periodos mas largos de observación con solo diferencias significativas en el grupo del día 42 entre materiales cubiertos (17.85, 32.2%, 47%) y no cubiertos (35.5%, 40.55%, 51.81%). Conclusión: La evaluación del lado curvado del implante de prueba no mostró una gran variación del contacto hueso implante dentro de los tiempos de observación descritos. Este modelo simula la situación usual de inserción del implante. El material cubierto de diamante se osteointegra en un momento posterior. El contacto hueso implante fue solo estadísticamente relevante en un grupo en comparación con el material no cubierto. [source] Scaling of lactate threshold by peak oxygen uptake and by fat-free mass0·67CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 3 2007James A. Davis Summary The lactate threshold (LT) represents the onset of metabolic acidosis during cardiopulmonary exercise testing (CPET). It is measured as a O2 in the units of ml min,1. In order to make comparisons among subjects, LT is often scaled or normalized by O2 peak resulting in the LT/O2 peak ratio. Ratio variables have underlying assumptions. One assumption is that the relationship between the numerator and denominator is linear with a zero y -intercept. If the relationship has a positive y -intercept, then the ratio will decrease with increasing values of the scaling variable thereby penalizing subjects with larger values of the scaling variable. Our purpose was to examine the validity of scaling LT by O2 peak and by fat-free mass raised to 0·67 power (FFM0·67) as dimensional analysis predicts that LT is proportional to FFM0·67. Cycle ergometer CPET was administered to 204 healthy, sedentary subjects (103 males) to the limit of tolerance. Lactate threshold was estimated noninvasively using the V-slope technique. Fat-free mass was assessed by skinfolds. The relationship of LT versus O2 peak was linear with a positive y -intercept for both sexes. Consequently, the LT/O2 peak ratio decreased as O2 peak increased for both sexes. The relationship of LT versus FFM0·67was linear with a zero y -intercept for both sexes. Consequently, the plot of the LT/FFM0·67 ratio versus FFM resulted in a straight line with a slope of zero for both sexes. The results of this study support the conclusion that FFM0·67, but not O2 peak, is a valid scaling variable for LT. [source] | |||||||||||||