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Time Duration (time + duration)
Selected AbstractsDamaging properties of ground motions and prediction of maximum response of structures based on momentary energy responseEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 9 2002Norio Hori Abstract Dynamic damaging potential of ground motions must be evaluated by the response behaviour of structures, and it is necessary to indicate what properties of ground motions are most appropriate for evaluation. For that purpose, the behaviour of energy input process and hysteretic energy dissipation are investigated in this study. It is found that the momentary input energy that is an index for the intensity of input energy is related to the characteristics of earthquakes such as cyclic or impulsive, and to the response displacement of structures immediately. On the basis of these results, a procedure is proposed to predict inelastic response displacement of structures by corresponding earthquake input energy to structural dissipated damping and hysteretic energy. In this procedure the earthquake response of structures is recognized as an input and dissipation process of energy, and therefore structural properties and damaging properties of ground motions can be taken into account more generally. Lastly, the studies of the pseudodynamic loading test of reinforced concrete structure specimens subjected to ground motions with different time duration are shown. The purpose of this test is to estimate the damaging properties of ground motions and the accuracy of the proposed prediction procedure. Copyright © 2002 John Wiley & Sons, Ltd. [source] Hydrograph and unit hydrograph derivation in arid regionsHYDROLOGICAL PROCESSES, Issue 8 2007Zekai Abstract Arid and semi-arid regions expose special hydrological features that are distinctive from humid areas. Unfortunately, humid-region hydrological empirical formulations are used directly in the arid and semi-arid regions without care about the basic assumptions. During any storm rainfall in arid regions, rainfall, infiltration and runoff components of the hydrological cycle have impacts on water resources. The basis of the methodology presented in this paper is the ratio of runoff increment to rainfall increment during an infinitesimally small time duration. This is the definition of runoff coefficient for the same infinitesimal time duration. The ratio is obtained through rational, physical and mathematical combination of hydrological thinking and then integrated with the classical infiltration equation for the hydrograph determination. The parameters of the methodology are explained and their empirical estimations are presented. The methodology works for rainfall and runoff from ungauged watersheds where infiltration measurement can be performed. The comparison of the new approach with different classical approaches, such as the rational formula and Soil Conservation Service method, are presented in detail. Its application is performed for two wadis within the Kingdom of Saudi Arabia. Copyright © 2006 John Wiley & Sons, Ltd. [source] The maximum principle violations of the mixed-hybrid finite-element method applied to diffusion equationsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 12 2002H. Hoteit Abstract The abundant literature of finite-element methods applied to linear parabolic problems, generally, produces numerical procedures with satisfactory properties. However, some initial,boundary value problems may cause large gradients at some points and consequently jumps in the solution that usually needs a certain period of time to become more and more smooth. This intuitive fact of the diffusion process necessitates, when applying numerical methods, varying the mesh size (in time and space) according to the smoothness of the solution. In this work, the numerical behaviour of the time-dependent solutions for such problems during small time duration obtained by using a non-conforming mixed-hybrid finite-element method (MHFEM) is investigated. Numerical comparisons with the standard Galerkin finite element (FE) as well as the finite-difference (FD) methods are checked. Owing to the fact that the mixed methods violate the discrete maximum principle, some numerical experiments showed that the MHFEM leads sometimes to non-physical peaks in the solution. A diffusivity criterion relating the mesh steps for an artificial initial,boundary value problem will be presented. One of the propositions given to avoid any non-physical oscillations is to use the mass-lumping techniques. Copyright © 2002 John Wiley & Sons, Ltd. [source] Interleukin-10 gene promoter polymorphism in Polish rheumatoid arthritis patientsINTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 4 2010A. Paradowska-Gorycka Summary Interleukin (IL)-10 is an important multifunctional cytokine with both anti-inflammatory and immunoregulatory effects in rheumatoid arthritis (RA). In the present study, we evaluated the frequency and potential impact of IL-10 promoter polymorphisms on susceptibility to and severity of RA in Polish in , patients with a high disease activity (mean DAS 28 C-reactive protein 5.25). DNA was obtained from 244 RA patients and 106 healthy controls. The ,592C/A and ,1082G/A IL-10 gene polymorphisms were amplified by polymerase chain reaction with restriction endonuclease mapping. The frequency of the IL-10-592CA, -592AA genotypes (respectively: 30% vs 5% and 7% vs 0%) and allele ,592A (37% vs 5%) were significantly higher in RA patients as compared with a control group. We did not find any association of the IL-10-592C/A genotype distribution with disease parameters, except for an increased ESR (erythrocyte sedimentation rate) in patients with the ,592CC genotype as compared with those with ,592CA or ,592AA genotypes (P = 0.01). The frequency of the IL-10-1082GG genotype was lower (P = 0.0001), and that of the IL-10-1082GA genotype was higher (P = 0.009) in RA patients comparing with the control group. In RA patients with ,1082GA or ,1082AA genotypes the time duration of the disease (P = 0.03), Health Assessment Questionnaire (HAQ) Score (P = 0.04) and PLT count (P = 0.001) were significantly increased as compared with subjects with ,1082GG genotype. Presented findings indicate that IL-10-592C/A and IL-10-1082G/A polymorphisms may be considered genetic risk factors for RA susceptibility and severity. [source] On the electrostatic equilibrium of granular flow in pneumatic conveying systemsAICHE JOURNAL, Issue 11 2006Jun Yao Abstract An analytical methodology involving the concept of "electrostatic equilibrium" is developed for granular flow in pneumatic conveying systems. The methodology can be used for estimation of the electrostatic field distribution at various sections of the system and explanation of the mechanisms involved for various electrostatic phenomena observed. For all cases conducted in the conveying system, there was a "charging time" required for the system to reach the state of "electrostatic equilibrium." Experiments conducted at different sections of the system showed that the time required increased in the order: horizontal pipe, vertical pipe, and pipe bend. Through a physical analysis, it is deduced that electrostatic equilibrium is related to the granules' behavior and local flow characteristics. In general, a longer time duration taken to reach equilibrium corresponds to a process with more complicated granular flow patterns. In the electrostatic equilibrium state, the field distribution shows the highest electrostatic field strength near the pipe wall, and this field strength degrades from the pipe wall to the pipe center. At various pipe sections, the highest strength occurs at the bend, in accord with observations that electric sparking first occurs at that location within the entire pneumatic conveying system. In the vertical pipe, granular distribution was measured using electrical capacitance tomography (ECT), and granular velocities were cross-referenced with those using particle image velocimetry (PIV). The electrostatic force at low air flow rates is found to be the primary cause for granules sticking to the pipe wall and results in the formation of the half-ring or ring structure. The state of electrostatic equilibrium is physically influenced by several elements in conveying systems. In a cyclic conveying system, a new pipe (or low humidity or no antistatic agent) tends to expedite the process to reach electrostatic equilibrium and attain high magnitude of electrostatic current at the state. In a non-cyclic horizontal conveying system, a thin film (pipe) is found to prolong the process duration to reach equilibrium, while the case with charged film (pipe) takes shorter duration to do so. © 2006 American Institute of Chemical Engineers AIChE J, 2006 [source] Relation between C-reactive protein levels and body composition in a multiethnic sample of school children in HawaiiAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 5 2010Daniel E. Brown Objectives: Adipose cells secrete proinflammatory cytokines that stimulate hepatic production of C-reactive protein (CRP). CRP levels are associated with adiposity levels in adults, adolescents, and older children but not in young children (age 2,3). This study examined the relation between CRP, adiposity, and cardiovascular and metabolic variables including blood pressure, glucose, and blood lipids in two young cohorts of children, averaging ,5.5 and 8.5 years, respectively. Methods: Children (N = 125) from eight elementary schools in the multiethnic community of Hilo Hawaii were recruited to fill out questionnaires, undergo anthropometrics and air displacement plethysmography, have resting blood pressure measured, and provide a finger stick blood sample for analysis of CRP, glucose, and blood lipids. Results: There were no significant differences between the cohorts in ethnic make up, household income, or parents' educational attainment. No significant relation was found between CRP and either adiposity or cardiovascular/metabolic variables in the younger cohort. However, significant correlations were found between CRP and adiposity measures and blood pressure in the older cohort. There was no marked difference in association of CRP with BMI versus waist circumference or waist-to-hip ratio. In neither cohort was CRP significantly related to glucose or blood lipids. Conclusions: Both amount of fat mass and time duration for possessing the adipose tissue may be important factors in determining the relation between CRP and both adiposity and blood pressure. Am. J. Hum. Biol. 22:675,679, 2010. © 2010 Wiley-Liss, Inc. [source] Time and the Price Impact of a TradeTHE JOURNAL OF FINANCE, Issue 6 2000Alfonso Dufour We use Hasbrouck's (1991) vector autoregressive model for prices and trades to empirically test and assess the role played by the waiting time between consecutive transactions in the process of price formation. We find that as the time duration between transactions decreases, the price impact of trades, the speed of price adjustment to trade-related information, and the positive autocorrelation of signed trades all increase. This suggests that times when markets are most active are times when there is an increased presence of informed traders; we interpret such markets as having reduced liquidity. [source] The impact of time duration between trades on the price of treasury note futures contractsTHE JOURNAL OF FUTURES MARKETS, Issue 10 2004Mark E. Holder Recent research in finance has indicated that the institutional structure in which financial asset prices are determined can have a nontrivial impact on pricing. This report examines transaction level data for Treasury Note futures contracts traded at the Chicago Board of Trade (CBOT) to identify institutional, or market microstructure, impacts on the pricing of these contracts. Relatively few articles have conducted empirical research on the microstructure of U.S. futures trading due to the limited availability of comprehensive transaction level data from the futures exchanges. This report uses the CBOT's Computerized Trade Reconstruction database, a comprehensive transaction level dataset, to identify the price impact of the time duration between trades in a manner analogous to that of A. Dufour and R. F. Engle (2000). Unique differences from prior research include the application to futures contracts with their relative higher frequency of trading, as well as the investigation of the price impact of the number of active traders present on the trading floor and the trading volume. Subsequent price and sign of trade significantly relate to the time duration between trades, the number of floor brokers, and the trading volume. © 2004 Wiley Periodicals, Inc. Jrl. Fut Mark 24:965,980, 2004 [source] Accelerating seismicity of moderate-size earthquakes before the 1999 Chi-Chi, Taiwan, earthquake: Testing time-prediction of the self-organizing spinodal model of earthquakesGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 1 2003Chien-chih Chen SUMMARY Seismic activation of moderate-size earthquakes for the 1999 Chi-Chi, Taiwan, earthquake has been found. A self-organizing spinodal (SOS) model can explain some observations concerning seismic activation, but the equal time durations of the mid and precursory periods during an earthquake cycle conjectured in the original, published, SOS model have not been supported in this case. The Chi-Chi test presented here shows unequal time durations of the mid and precursory periods of an earthquake cycle. This, in turn, makes the possibility of time prediction of a characteristic earthquake impossible in the context of the SOS model. In addition, comparisons with numerical simulations of the sliding-block model suggest the change in the system's stiffness is a potential mechanism of seismic activation. [source] | |||||||||||||