Modeling maximum daily temperature using a varying coefficient regression model

Science.gov (United States)

Han Li; Xinwei Deng; Dong-Yum Kim; Eric P. Smith

2014-01-01

Relationships between stream water and air temperatures are often modeled using linear or nonlinear regression methods. Despite a strong relationship between water and air temperatures and a variety of models that are effective for data summarized on a weekly basis, such models did not yield consistently good predictions for summaries such as daily maximum temperature...

Characteristics of Plantar Loads in Maximum Forward Lunge Tasks in Badminton.

Science.gov (United States)

Hu, Xiaoyue; Li, Jing Xian; Hong, Youlian; Wang, Lin

2015-01-01

Badminton players often perform powerful and long-distance lunges during such competitive matches. The objective of this study is to compare the plantar loads of three one-step maximum forward lunges in badminton. Fifteen right-handed male badminton players participated in the study. Each participant performed five successful maximum lunges at three directions. For each direction, the participant wore three different shoe brands. Plantar loading, including peak pressure, maximum force, and contact area, was measured by using an insole pressure measurement system. Two-way ANOVA with repeated measures was employed to determine the effects of the different lunge directions and different shoes, as well as the interaction of these two variables, on the measurements. The maximum force (MF) on the lateral midfoot was lower when performing left-forward lunges than when performing front-forward lunges (p = 0.006, 95% CI = -2.88 to -0.04%BW). The MF and peak pressures (PP) on the great toe region were lower for the front-forward lunge than for the right-forward lunge (MF, p = 0.047, 95% CI = -3.62 to -0.02%BW; PP, p = 0.048, 95% CI = -37.63 to -0.16 KPa) and left-forward lunge (MF, p = 0.015, 95% CI = -4.39 to -0.38%BW; PP, p = 0.008, 95% CI = -47.76 to -5.91 KPa). These findings indicate that compared with the front-forward lunge, left and right maximum forward lunges induce greater plantar loads on the great toe region of the dominant leg of badminton players. The differences in the plantar loads of the different lunge directions may be potential risks for injuries to the lower extremities of badminton players.

Characteristics of Plantar Loads in Maximum Forward Lunge Tasks in Badminton.

Directory of Open Access Journals (Sweden)

Xiaoyue Hu

Full Text Available Badminton players often perform powerful and long-distance lunges during such competitive matches. The objective of this study is to compare the plantar loads of three one-step maximum forward lunges in badminton.Fifteen right-handed male badminton players participated in the study. Each participant performed five successful maximum lunges at three directions. For each direction, the participant wore three different shoe brands. Plantar loading, including peak pressure, maximum force, and contact area, was measured by using an insole pressure measurement system. Two-way ANOVA with repeated measures was employed to determine the effects of the different lunge directions and different shoes, as well as the interaction of these two variables, on the measurements.The maximum force (MF on the lateral midfoot was lower when performing left-forward lunges than when performing front-forward lunges (p = 0.006, 95% CI = -2.88 to -0.04%BW. The MF and peak pressures (PP on the great toe region were lower for the front-forward lunge than for the right-forward lunge (MF, p = 0.047, 95% CI = -3.62 to -0.02%BW; PP, p = 0.048, 95% CI = -37.63 to -0.16 KPa and left-forward lunge (MF, p = 0.015, 95% CI = -4.39 to -0.38%BW; PP, p = 0.008, 95% CI = -47.76 to -5.91 KPa.These findings indicate that compared with the front-forward lunge, left and right maximum forward lunges induce greater plantar loads on the great toe region of the dominant leg of badminton players. The differences in the plantar loads of the different lunge directions may be potential risks for injuries to the lower extremities of badminton players.

Short-term load forecasting of power system

Science.gov (United States)

Xu, Xiaobin

2017-05-01

In order to ensure the scientific nature of optimization about power system, it is necessary to improve the load forecasting accuracy. Power system load forecasting is based on accurate statistical data and survey data, starting from the history and current situation of electricity consumption, with a scientific method to predict the future development trend of power load and change the law of science. Short-term load forecasting is the basis of power system operation and analysis, which is of great significance to unit combination, economic dispatch and safety check. Therefore, the load forecasting of the power system is explained in detail in this paper. First, we use the data from 2012 to 2014 to establish the partial least squares model to regression analysis the relationship between daily maximum load, daily minimum load, daily average load and each meteorological factor, and select the highest peak by observing the regression coefficient histogram Day maximum temperature, daily minimum temperature and daily average temperature as the meteorological factors to improve the accuracy of load forecasting indicators. Secondly, in the case of uncertain climate impact, we use the time series model to predict the load data for 2015, respectively, the 2009-2014 load data were sorted out, through the previous six years of the data to forecast the data for this time in 2015. The criterion for the accuracy of the prediction is the average of the standard deviations for the prediction results and average load for the previous six years. Finally, considering the climate effect, we use the BP neural network model to predict the data in 2015, and optimize the forecast results on the basis of the time series model.

Dynamic Regression Intervention Modeling for the Malaysian Daily Load

Directory of Open Access Journals (Sweden)

Fadhilah Abdrazak

2014-05-01

Full Text Available Malaysia is a unique country due to having both fixed and moving holidays.  These moving holidays may overlap with other fixed holidays and therefore, increase the complexity of the load forecasting activities. The errors due to holidays’ effects in the load forecasting are known to be higher than other factors.  If these effects can be estimated and removed, the behavior of the series could be better viewed.  Thus, the aim of this paper is to improve the forecasting errors by using a dynamic regression model with intervention analysis.   Based on the linear transfer function method, a daily load model consists of either peak or average is developed.  The developed model outperformed the seasonal ARIMA model in estimating the fixed and moving holidays’ effects and achieved a smaller Mean Absolute Percentage Error (MAPE in load forecast.

Estimate of annual daily maximum rainfall and intense rain equation for the Formiga municipality, MG, Brazil

Directory of Open Access Journals (Sweden)

Giovana Mara Rodrigues Borges

2016-11-01

Full Text Available Knowledge of the probabilistic behavior of rainfall is extremely important to the design of drainage systems, dam spillways, and other hydraulic projects. This study therefore examined statistical models to predict annual daily maximum rainfall as well as models of heavy rain for the city of Formiga - MG. To do this, annual maximum daily rainfall data were ranked in decreasing order that best describes the statistical distribution by exceedance probability. Daily rainfall disaggregation methodology was used for the intense rain model studies and adjusted with Intensity-Duration-Frequency (IDF and Exponential models. The study found that the Gumbel model better adhered to the data regarding observed frequency as indicated by the Chi-squared test, and that the exponential model best conforms to the observed data to predict intense rains.

Interaction between daily load demand curve and management of hydro-thermal generation system

International Nuclear Information System (INIS)

Granelli, G.; Montagna, M.; Pasini, G.; Innorta, M.; Marannino, P.

1993-01-01

The influence that the behaviour of the daily load demand curve has on the management of a hydro-thermal generation system is considered. The aim of this paper is to show the improvements that can be achieved by suitable load management techniques capable of flattening the load demand curve. The analysis is carried out by using a hydro-thermal scheduling program and a thermal unit dynamic dispatch procedure. The possibility of properly re-committing the available thermal units is also taken into account. The economical and technical convenience of shutting down less economical thermal units operating near the lower generations limits is verified. Finally, some considerations are made about the possible use of the thermal generation incremental costs as a tool for planning the end users' kWh prices, even in the short term. The results refer to a system with characteristics similar to those of the Italian one. In determining the daily load demand curves, the characteristics of load demand in Italy as well as in other European countries are taken into account

Application of Markov chain model to daily maximum temperature for thermal comfort in Malaysia

International Nuclear Information System (INIS)

Nordin, Muhamad Asyraf bin Che; Hassan, Husna

2015-01-01

The Markov chain’s first order principle has been widely used to model various meteorological fields, for prediction purposes. In this study, a 14-year (2000-2013) data of daily maximum temperatures in Bayan Lepas were used. Earlier studies showed that the outdoor thermal comfort range based on physiologically equivalent temperature (PET) index in Malaysia is less than 34°C, thus the data obtained were classified into two state: normal state (within thermal comfort range) and hot state (above thermal comfort range). The long-run results show the probability of daily temperature exceed TCR will be only 2.2%. On the other hand, the probability daily temperature within TCR will be 97.8%

TRENDS IN ESTIMATED MIXING DEPTH DAILY MAXIMUMS

Energy Technology Data Exchange (ETDEWEB)

Buckley, R; Amy DuPont, A; Robert Kurzeja, R; Matt Parker, M

2007-11-12

Mixing depth is an important quantity in the determination of air pollution concentrations. Fireweather forecasts depend strongly on estimates of the mixing depth as a means of determining the altitude and dilution (ventilation rates) of smoke plumes. The Savannah River United States Forest Service (USFS) routinely conducts prescribed fires at the Savannah River Site (SRS), a heavily wooded Department of Energy (DOE) facility located in southwest South Carolina. For many years, the Savannah River National Laboratory (SRNL) has provided forecasts of weather conditions in support of the fire program, including an estimated mixing depth using potential temperature and turbulence change with height at a given location. This paper examines trends in the average estimated mixing depth daily maximum at the SRS over an extended period of time (4.75 years) derived from numerical atmospheric simulations using two versions of the Regional Atmospheric Modeling System (RAMS). This allows for differences to be seen between the model versions, as well as trends on a multi-year time frame. In addition, comparisons of predicted mixing depth for individual days in which special balloon soundings were released are also discussed.

Accurate computations of monthly average daily extraterrestrial irradiation and the maximum possible sunshine duration

International Nuclear Information System (INIS)

Jain, P.C.

1985-12-01

The monthly average daily values of the extraterrestrial irradiation on a horizontal plane and the maximum possible sunshine duration are two important parameters that are frequently needed in various solar energy applications. These are generally calculated by solar scientists and engineers each time they are needed and often by using the approximate short-cut methods. Using the accurate analytical expressions developed by Spencer for the declination and the eccentricity correction factor, computations for these parameters have been made for all the latitude values from 90 deg. N to 90 deg. S at intervals of 1 deg. and are presented in a convenient tabular form. Monthly average daily values of the maximum possible sunshine duration as recorded on a Campbell Stoke's sunshine recorder are also computed and presented. These tables would avoid the need for repetitive and approximate calculations and serve as a useful ready reference for providing accurate values to the solar energy scientists and engineers

Evaluation of empirical relationships between extreme rainfall and daily maximum temperature in Australia

Science.gov (United States)

Herath, Sujeewa Malwila; Sarukkalige, Ranjan; Nguyen, Van Thanh Van

2018-01-01

Understanding the relationships between extreme daily and sub-daily rainfall events and their governing factors is important in order to analyse the properties of extreme rainfall events in a changing climate. Atmospheric temperature is one of the dominant climate variables which has a strong relationship with extreme rainfall events. In this study, a temperature-rainfall binning technique is used to evaluate the dependency of extreme rainfall on daily maximum temperature. The Clausius-Clapeyron (C-C) relation was found to describe the relationship between daily maximum temperature and a range of rainfall durations from 6 min up to 24 h for seven Australian weather stations, the stations being located in Adelaide, Brisbane, Canberra, Darwin, Melbourne, Perth and Sydney. The analysis shows that the rainfall - temperature scaling varies with location, temperature and rainfall duration. The Darwin Airport station shows a negative scaling relationship, while the other six stations show a positive relationship. To identify the trend in scaling relationship over time the same analysis is conducted using data covering 10 year periods. Results indicate that the dependency of extreme rainfall on temperature also varies with the analysis period. Further, this dependency shows an increasing trend for more extreme short duration rainfall and a decreasing trend for average long duration rainfall events at most stations. Seasonal variations of the scale changing trends were analysed by categorizing the summer and autumn seasons in one group and the winter and spring seasons in another group. Most of 99th percentile of 6 min, 1 h and 24 h rain durations at Perth, Melbourne and Sydney stations show increasing trend for both groups while Adelaide and Darwin show decreasing trend. Furthermore, majority of scaling trend of 50th percentile are decreasing for both groups.

New England observed and predicted August stream/river temperature maximum positive daily rate of change points

Data.gov (United States)

U.S. Environmental Protection Agency — The shapefile contains points with associated observed and predicted August stream/river temperature maximum positive daily rate of change in New England based on a...

New England observed and predicted July stream/river temperature maximum positive daily rate of change points

Data.gov (United States)

U.S. Environmental Protection Agency — The shapefile contains points with associated observed and predicted July stream/river temperature maximum positive daily rate of change in New England based on a...

New England observed and predicted July maximum negative stream/river temperature daily rate of change points

Data.gov (United States)

U.S. Environmental Protection Agency — The shapefile contains points with associated observed and predicted July stream/river temperature maximum negative daily rate of change in New England based on a...

STATIONARITY OF ANNUAL MAXIMUM DAILY STREAMFLOW TIME SERIES IN SOUTH-EAST BRAZILIAN RIVERS

Directory of Open Access Journals (Sweden)

Jorge Machado Damázio

2015-08-01

Full Text Available DOI: 10.12957/cadest.2014.18302The paper presents a statistical analysis of annual maxima daily streamflow between 1931 and 2013 in South-East Brazil focused in detecting and modelling non-stationarity aspects. Flood protection for the large valleys in South-East Brazil is provided by multiple purpose reservoir systems built during 20th century, which design and operation plans has been done assuming stationarity of historical flood time series. Land cover changes and rapidly-increasing level of atmosphere greenhouse gases of the last century may be affecting flood regimes in these valleys so that it can be that nonstationary modelling should be applied to re-asses dam safety and flood control operation rules at the existent reservoir system. Six annual maximum daily streamflow time series are analysed. The time series were plotted together with fitted smooth loess functions and non-parametric statistical tests are performed to check the significance of apparent trends shown by the plots. Non-stationarity is modelled by fitting univariate extreme value distribution functions which location varies linearly with time. Stationarity and non-stationarity modelling are compared with the likelihood ratio statistic. In four of the six analyzed time series non-stationarity modelling outperformed stationarity modelling.Keywords: Stationarity; Extreme Value Distributions; Flood Frequency Analysis; Maximum Likelihood Method.

Linear and regressive stochastic models for prediction of daily maximum ozone values at Mexico City atmosphere

Energy Technology Data Exchange (ETDEWEB)

Bravo, J. L [Instituto de Geofisica, UNAM, Mexico, D.F. (Mexico); Nava, M. M [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Gay, C [Centro de Ciencias de la Atmosfera, UNAM, Mexico, D.F. (Mexico)

2001-07-01

We developed a procedure to forecast, with 2 or 3 hours, the daily maximum of surface ozone concentrations. It involves the adjustment of Autoregressive Integrated and Moving Average (ARIMA) models to daily ozone maximum concentrations at 10 monitoring atmospheric stations in Mexico City during one-year period. A one-day forecast is made and it is adjusted with the meteorological and solar radiation information acquired during the first 3 hours before the occurrence of the maximum value. The relative importance for forecasting of the history of the process and of meteorological conditions is evaluated. Finally an estimate of the daily probability of exceeding a given ozone level is made. [Spanish] Se aplica un procedimiento basado en la metodologia conocida como ARIMA, para predecir, con 2 o 3 horas de anticipacion, el valor maximo de la concentracion diaria de ozono. Esta basado en el calculo de autorregresiones y promedios moviles aplicados a los valores maximos de ozono superficial provenientes de 10 estaciones de monitoreo atmosferico en la Ciudad de Mexico y obtenidos durante un ano de muestreo. El pronostico para un dia se ajusta con la informacion meteorologica y de radiacion solar correspondiente a un periodo que antecede con al menos tres horas la ocurrencia esperada del valor maximo. Se compara la importancia relativa de la historia del proceso y de las condiciones meteorologicas previas para el pronostico. Finalmente se estima la probabilidad diaria de que un nivel normativo o preestablecido para contingencias de ozono sea rebasado.

Pressurizer /Auxiliary Spray Piping Stress Analysis For Determination Of Lead Shielding Maximum Allow Able Load

International Nuclear Information System (INIS)

Setjo, Renaningsih

2000-01-01

Piping stress analysis for PZR/Auxiliary Spray Lines Nuclear Power Plant AV Unit I(PWR Type) has been carried out. The purpose of this analysis is to establish a maximum allowable load that is permitted at the time of need by placing lead shielding on the piping system on class 1 pipe, Pressurizer/Auxiliary Spray Lines (PZR/Aux.) Reactor Coolant Loop 1 and 4 for NPP AV Unit one in the mode 5 and 6 during outage. This analysis is intended to reduce the maximum amount of radiation dose for the operator during ISI ( In service Inspection) period.The result shown that the maximum allowable loads for 4 inches lines for PZR/Auxiliary Spray Lines is 123 lbs/feet

The contact mechanics and occurrence of edge loading in modular metal-on-polyethylene total hip replacement during daily activities.

Science.gov (United States)

Hua, Xijin; Li, Junyan; Jin, Zhongmin; Fisher, John

2016-06-01

The occurrence of edge loading in hip joint replacement has been associated with many factors such as prosthetic design, component malposition and activities of daily living. The present study aimed to quantify the occurrence of edge loading/contact at the articulating surface and to evaluate the effect of cup angles and edge loading on the contact mechanics of a modular metal-on-polyethylene (MoP) total hip replacement (THR) during different daily activities. A three-dimensional finite element model was developed based on a modular MoP bearing system. Different cup inclination and anteversion angles were modelled and six daily activities were considered. The results showed that edge loading was predicted during normal walking, ascending and descending stairs activities under steep cup inclination conditions (≥55°) while no edge loading was observed during standing up, sitting down and knee bending activities. The duration of edge loading increased with increased cup inclination angles and was affected by the cup anteversion angles. Edge loading caused elevated contact pressure at the articulating surface and substantially increased equivalent plastic strain of the polyethylene liner. The present study suggested that correct positioning the component to avoid edge loading that may occur during daily activities is important for MoP THR in clinical practice. Copyright © 2016. Published by Elsevier Ltd.

Automatic Control of Reactor Temperature and Power Distribution for a Daily Load following Operation

Energy Technology Data Exchange (ETDEWEB)

Yu, Keuk Jong; Kim, Han Gon [Korea Hydro and Nuclear Power Institute, Daejeon (Korea, Republic of)

2010-10-15

An automatic control method of reactor power and power distribution was developed for a daily load following operation of APR1400. This method used a model predictive control (MPC) methodology having second-order plant data. And it utilized a reactor power ratio and axial shape index as control variables. However, the reactor regulating system of APR1400 is operated by the difference between the average temperature of the reactor core and the reference temperature, which is proportional to the turbine load. Thus, this paper reports on the model predictive control methodology using fourth-order plant data and a reactor temperature instead of the reactor power shape. The purpose of this study is to develop a revised automatic controller and analyze the behavior of the nuclear reactor temperature (Tavg) and the axial shape index (ASI) using the MPC method during a daily load following operation

Fission gas release behavior of MOX fuels under simulated daily-load-follow operation condition. IFA-554/555 test evaluation with FASTGRASS code

International Nuclear Information System (INIS)

Ikusawa, Yoshihisa; Ozawa, Takayuki

2008-03-01

IFA-554/555 load-follow tests were performed in HALDEN reactor (HBWR) to study the MOX fuel behavior under the daily-load-follow operation condition in the framework of ATR-MOX fuel development in JAEA. IFA-554/555 rig had the instruments of rod inner pressure, fuel center temperature, fuel stack elongation, and cladding elongation. Although the daily-load-follow operation in nuclear power plant is one of the available options for economical improvement, the power change in a short period in this operation causes the change of thermal and mechanical irradiation conditions. In this report, FP gas release behavior of MOX fuel rod was evaluated under the daily-load-follow operation condition with the examination data from IFA-554/555 by using the computation code 'FASTGRASS'. From the computation results of FASTGRASS code which could compute the FP gas release behavior under the transient condition, it could be concluded that FP gas was released due to the relaxation of fuel pellet inner stress and pellet temperature increase, which were caused by the cyclic power change during the daily-load-follow operation. In addition, since the amount of released FP gas decreased during the steady operation after the daily-load-follow, it could be mentioned that the total of FP gas release at the end of life with the daily-load-follow is not so much different from that without the daily-load-follow. (author)

Monitoring to assess progress toward meeting the Assabet River, Massachusetts, phosphorus total maximum daily load - Aquatic macrophyte biomass and sediment-phosphorus flux

Science.gov (United States)

Zimmerman, Marc J.; Qian, Yu; Yong Q., Tian

2011-01-01

In 2004, the Total Maximum Daily Load (TMDL) for Total Phosphorus in the Assabet River, Massachusetts, was approved by the U.S. Environmental Protection Agency. The goal of the TMDL was to decrease the concentrations of the nutrient phosphorus to mitigate some of the instream ecological effects of eutrophication on the river; these effects were, for the most part, direct consequences of the excessive growth of aquatic macrophytes. The primary instrument effecting lower concentrations of phosphorus was to be strict control of phosphorus releases from four major wastewatertreatment plants in Westborough, Marlborough, Hudson, and Maynard, Massachusetts. The improvements to be achieved from implementing this control were lower concentrations of total and dissolved phosphorus in the river, a 50-percent reduction in aquatic-plant biomass, a 30-percent reduction in episodes of dissolved oxygen supersaturation, no low-flow dissolved oxygen concentrations less than 5.0 milligrams per liter, and a 90-percent reduction in sediment releases of phosphorus to the overlying water. In 2007, the U.S. Geological Survey, in cooperation with the Massachusetts Department of Environmental Protection, initiated studies to evaluate conditions in the Assabet River prior to the upgrading of wastewater-treatment plants to remove more phosphorus from their effluents. The studies, completed in 2008, implemented a visual monitoring plan to evaluate the extent and biomass of the floating macrophyte Lemna minor (commonly known as lesser duckweed) in five impoundments and evaluated the potential for phosphorus flux from sediments in impounded and free-flowing reaches of the river. Hydrologically, the two study years 2007 and 2008 were quite different. In 2007, summer streamflows, although low, were higher than average, and in 2008, the flows were generally higher than in 2007. Visually, the effects of these streamflow differences on the distribution of Lemna were obvious. In 2007, large amounts of

Abdominal crunch exercise analysis performed with maximum and submaximum loads: An electromyographic study

Directory of Open Access Journals (Sweden)

M.L. Moura

2011-01-01

Full Text Available The purpose of this study was to verify the electromyographic activity of the rectus abdominis and obliquus externus abdominis during abdominal crunch exercise performed with maximum and submaximum loads. Thirteen male and female university students participated in this investigation (18-23 years old. The subjects completed abdominal crunch exercise until exhaustion with 20, 40, 60 and 80% of the maximum load. The root-mean-square (RMS from electromyography activity of the rectus abdominis and obliquus externus muscles from the first and last three repetitions from each workload performed was analyzed. RMS for the last repetitions increased in relation to the first repetitions for the 20% workload, first two repetitions on 40% workload and first repetition on the 80% workload. There was no difference for the 60% workload. Results showed that external load on abdominal crunch exercise might be an alternative to increase intensity while performing abdominal crunch exercise, which on its turn can be a practical tool for subjects that aim to increase abdominal strength level.

Estimation and prediction of maximum daily rainfall at Sagar Island using best fit probability models

Science.gov (United States)

Mandal, S.; Choudhury, B. U.

2015-07-01

Sagar Island, setting on the continental shelf of Bay of Bengal, is one of the most vulnerable deltas to the occurrence of extreme rainfall-driven climatic hazards. Information on probability of occurrence of maximum daily rainfall will be useful in devising risk management for sustaining rainfed agrarian economy vis-a-vis food and livelihood security. Using six probability distribution models and long-term (1982-2010) daily rainfall data, we studied the probability of occurrence of annual, seasonal and monthly maximum daily rainfall (MDR) in the island. To select the best fit distribution models for annual, seasonal and monthly time series based on maximum rank with minimum value of test statistics, three statistical goodness of fit tests, viz. Kolmogorove-Smirnov test (K-S), Anderson Darling test ( A 2 ) and Chi-Square test ( X 2) were employed. The fourth probability distribution was identified from the highest overall score obtained from the three goodness of fit tests. Results revealed that normal probability distribution was best fitted for annual, post-monsoon and summer seasons MDR, while Lognormal, Weibull and Pearson 5 were best fitted for pre-monsoon, monsoon and winter seasons, respectively. The estimated annual MDR were 50, 69, 86, 106 and 114 mm for return periods of 2, 5, 10, 20 and 25 years, respectively. The probability of getting an annual MDR of >50, >100, >150, >200 and >250 mm were estimated as 99, 85, 40, 12 and 03 % level of exceedance, respectively. The monsoon, summer and winter seasons exhibited comparatively higher probabilities (78 to 85 %) for MDR of >100 mm and moderate probabilities (37 to 46 %) for >150 mm. For different recurrence intervals, the percent probability of MDR varied widely across intra- and inter-annual periods. In the island, rainfall anomaly can pose a climatic threat to the sustainability of agricultural production and thus needs adequate adaptation and mitigation measures.

Estimation of the mechanical loading of the shoulder joint in daily conditions

NARCIS (Netherlands)

De Vries, W.H.K.

2015-01-01

The goal of this thesis is to assemble a method to estimate shoulder joint reaction forces, in daily conditions, based on long term collection of ambulatory measurable variables, to obtain the desired long term mechanical load profile of the shoulder. Chapter 2 examines, and discusses one of the

A field studies and modeling approach to develop organochlorine pesticide and PCB total maximum daily load calculations: Case study for Echo Park Lake, Los Angeles, CA

Energy Technology Data Exchange (ETDEWEB)

Vasquez, V.R., E-mail: vrvasquez@ucla.edu [Environmental Science and Engineering Program, University of California, Los Angeles, Los Angeles, CA 90095-1496 (United States); Curren, J., E-mail: janecurren@yahoo.com [Environmental Science and Engineering Program, University of California, Los Angeles, Los Angeles, CA 90095-1496 (United States); Lau, S.-L., E-mail: simlin@ucla.edu [Department of Civil and Environmental Engineering, University of California, Los Angeles, Los Angeles, CA 90095-1496 (United States); Stenstrom, M.K., E-mail: stenstro@seas.ucla.edu [Department of Civil and Environmental Engineering, University of California, Los Angeles, Los Angeles, CA 90095-1496 (United States); Suffet, I.H., E-mail: msuffet@ucla.edu [Environmental Science and Engineering Program, University of California, Los Angeles, Los Angeles, CA 90095-1496 (United States)

2011-09-01

Echo Park Lake is a small lake in Los Angeles, CA listed on the USA Clean Water Act Section 303(d) list of impaired water bodies for elevated levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in fish tissue. A lake water and sediment sampling program was completed to support the development of total maximum daily loads (TMDL) to address the lake impairment. The field data indicated quantifiable levels of OCPs and PCBs in the sediments, but lake water data were all below detection levels. The field sediment data obtained may explain the contaminant levels in fish tissue using appropriate sediment-water partitioning coefficients and bioaccumulation factors. A partition-equilibrium fugacity model of the whole lake system was used to interpret the field data and indicated that half of the total mass of the pollutants in the system are in the sediments and the other half is in soil; therefore, soil erosion could be a significant pollutant transport mode into the lake. Modeling also indicated that developing and quantifying the TMDL depends significantly on the analytical detection level for the pollutants in field samples and on the choice of octanol-water partitioning coefficient and bioaccumulation factors for the model. - Research highlights: {yields} Fugacity model using new OCP and PCB field data supports lake TMDL calculations. {yields} OCP and PCB levels in lake sediment were found above levels for impairment. {yields} Relationship between sediment data and available fish tissue data evaluated. {yields} Model provides approximation of contaminant sources and sinks for a lake system. {yields} Model results were sensitive to analytical detection and quantification levels.

Determination of the wind power systems load to achieve operation in the maximum energy area

Science.gov (United States)

Chioncel, C. P.; Tirian, G. O.; Spunei, E.; Gillich, N.

2018-01-01

This paper analyses the operation of the wind turbine, WT, in the maximum power point, MPP, by linking the load of the Permanent Magnet Synchronous Generator, PMSG, with the wind speed value. The load control methods at wind power systems aiming an optimum performance in terms of energy are based on the fact that the energy captured by the wind turbine significantly depends on the mechanical angular speed of the wind turbine. The presented control method consists in determining the optimal mechanical angular speed, ωOPTIM, using an auxiliary low power wind turbine, WTAUX, operating without load, at maximum angular velocity, ωMAX. The method relies on the fact that the ratio ωOPTIM/ωMAX has a constant value for a given wind turbine and does not depend on the time variation of the wind speed values.

Maximum power point tracker for portable photovoltaic systems with resistive-like load

Energy Technology Data Exchange (ETDEWEB)

De Cesare, G.; Caputo, D.; Nascetti, A. [Department of Electronic Engineering, University of Rome La Sapienza via Eudossiana, 18 00184 Rome (Italy)

2006-08-15

In this work we report on the design and realization of a maximum power point tracking (MPPT) circuit suitable for low power, portable applications with resistive load. The design rules included cost, size and power efficiency considerations. A novel scheme for the implementation of the control loop of the MPPT circuit is proposed, combining good performance with compact design. The operation and performances were simulated at circuit schematic level with simulation program with integrated circuit emphasis (SPICE). The improved operation of a PV system using our MPPT circuit was demonstrated using a purely resistive load. (author)

Are daily and weekly load and spot price dynamics in Australia's National Electricity Market governed by episodic nonlinearity?

International Nuclear Information System (INIS)

Wild, Phillip; Hinich, Melvin J.; Foster, John

2010-01-01

In this article, we use half hourly spot electricity prices and load data for the National Electricity Market (NEM) of Australia for the period from December 1998 to June 2009 to test for episodic nonlinearity in the dynamics governing daily and weekly cycles in load and spot price time series data. We apply the portmanteau correlation, bicorrelation and tricorrelation tests introduced in Hinich (1996) to the time series of half hourly spot prices and load demand from 7/12/1998 to 30/06/2009 using a FORTRAN 95 program. We find the presence of significant third and fourth-order (nonlinear) serial dependence in the weekly load and spot price data in particular, but to a much more marginal extent, in the daily data. (author)

Spatial variability of maximum annual daily rain under different return periods at the Rio de Janeiro state, Brazil

Directory of Open Access Journals (Sweden)

Roriz Luciano Machado

2010-01-01

Full Text Available Knowledge of maximum daily rain and its return period in a region is an important tool to soil conservation, hydraulic engineering and preservation of road projects. The objective of this work was to evaluate the spatial variability of maximum annual daily rain considering different return periods, at the Rio de Janeiro State. The data set was composed by historical series of 119 rain gauges, for 36 years of observation. The return periods, estimated by Gumbel distribution, were 2, 5, 10, 25, 50 and 100 years. The spatial variability of the return periods was evaluated by semivariograms. All the return periods presented spatial dependence, with exponential and spherical model fitted to the experimental semivariograms. The parameters of the fitted semivariogram model were very similar; however, it was observed the presence of higher nugget effects for semivariograms of longer return periods. The values of maximum annual daily average rain in all the return periods increased from north to south and from countryside to the coast. In the region between the Serra do Mar range and the coast, besides increasing in magnitude, an increase in the spatial variability of the studied values with increasing return periods was also noticed. This behavior is probably caused by the orographic effect. The interpolated maps were more erratic for higher return periods and at the North, Northeast and Coastal Plain regions, in which the installation of new pluviometric stations are recommended.

Investigation of the maximum load alleviation potential using trailing edge flaps controlled by inflow data

DEFF Research Database (Denmark)

Fischer, Andreas; Aagaard Madsen, Helge

2014-01-01

The maximum fatigue load reduction potential when using trailing edge flaps on mega-watt wind turbines was explored. For this purpose an ideal feed forward control algorithm using the relative velocity and angle of attack at the blade to control the loads was implemented. The algorithm was applied...... to time series from computations with the aeroelastic code HAWC2 and to measured time series. The fatigue loads could be reduced by 36% in the computations if the in flow sensor was at the same position as the blade load. The decrease of the load reduction potential when the sensor was at a distance from...... the blade load location was investigated. When the algorithm was applied to measured time series a load reduction of 23% was achieved which is still promissing, but significantly lower than the value achieved in computations....

Operational forecasting of daily temperatures in the Valencia Region. Part I: maximum temperatures in summer.

Science.gov (United States)

Gómez, I.; Estrela, M.

2009-09-01

Extreme temperature events have a great impact on human society. Knowledge of summer maximum temperatures is very useful for both the general public and organisations whose workers have to operate in the open, e.g. railways, roadways, tourism, etc. Moreover, summer maximum daily temperatures are considered a parameter of interest and concern since persistent heat-waves can affect areas as diverse as public health, energy consumption, etc. Thus, an accurate forecasting of these temperatures could help to predict heat-wave conditions and permit the implementation of strategies aimed at minimizing the negative effects that high temperatures have on human health. The aim of this work is to evaluate the skill of the RAMS model in determining daily maximum temperatures during summer over the Valencia Region. For this, we have used the real-time configuration of this model currently running at the CEAM Foundation. To carry out the model verification process, we have analysed not only the global behaviour of the model for the whole Valencia Region, but also its behaviour for the individual stations distributed within this area. The study has been performed for the summer forecast period of 1 June - 30 September, 2007. The results obtained are encouraging and indicate a good agreement between the observed and simulated maximum temperatures. Moreover, the model captures quite well the temperatures in the extreme heat episodes. Acknowledgement. This work was supported by "GRACCIE" (CSD2007-00067, Programa Consolider-Ingenio 2010), by the Spanish Ministerio de Educación y Ciencia, contract number CGL2005-03386/CLI, and by the Regional Government of Valencia Conselleria de Sanitat, contract "Simulación de las olas de calor e invasiones de frío y su regionalización en la Comunidad Valenciana" ("Heat wave and cold invasion simulation and their regionalization at Valencia Region"). The CEAM Foundation is supported by the Generalitat Valenciana and BANCAIXA (Valencia, Spain).

Comparison of the Spatiotemporal Variability of Temperature, Precipitation, and Maximum Daily Spring Flows in Two Watersheds in Quebec Characterized by Different Land Use

Directory of Open Access Journals (Sweden)

Ali A. Assani

2016-01-01

Full Text Available We compared the spatiotemporal variability of temperatures and precipitation with that of the magnitude and timing of maximum daily spring flows in the geographically adjacent L’Assomption River (agricultural and Matawin River (forested watersheds during the period from 1932 to 2013. With regard to spatial variability, fall, winter, and spring temperatures as well as total precipitation are higher in the agricultural watershed than in the forested one. The magnitude of maximum daily spring flows is also higher in the first watershed as compared with the second, owing to substantial runoff, given that the amount of snow that gives rise to these flows is not significantly different in the two watersheds. These flows occur early in the season in the agricultural watershed because of the relatively high temperatures. With regard to temporal variability, minimum temperatures increased over time in both watersheds. Maximum temperatures in the fall only increased in the agricultural watershed. The amount of spring rain increased over time in both watersheds, whereas total precipitation increased significantly in the agricultural watershed only. However, the amount of snow decreased in the forested watershed. The magnitude of maximum daily spring flows increased over time in the forested watershed.

Genetic Analysis of Daily Maximum Milking Speed by a Random Walk Model in Dairy Cows

DEFF Research Database (Denmark)

Karacaören, Burak; Janss, Luc; Kadarmideen, Haja

Data were obtained from dairy cows stationed at research farm ETH Zurich for maximum milking speed. The main aims of this paper are a) to evaluate if the Wood curve is suitable to model mean lactation curve b) to predict longitudinal breeding values by random regression and random walk models of ...... filter applications: random walk model could give online prediction of breeding values. Hence without waiting for whole lactation records, genetic evaluation could be made when the daily or monthly data is available......Data were obtained from dairy cows stationed at research farm ETH Zurich for maximum milking speed. The main aims of this paper are a) to evaluate if the Wood curve is suitable to model mean lactation curve b) to predict longitudinal breeding values by random regression and random walk models...... of maximum milking speed. Wood curve did not provide a good fit to the data set. Quadratic random regressions gave better predictions compared with the random walk model. However random walk model does not need to be evaluated for different orders of regression coefficients. In addition with the Kalman...

Variable Parameter Nonlinear Control for Maximum Power Point Tracking Considering Mitigation of Drive-train Load

Institute of Scientific and Technical Information of China (English)

Zaiyu; Chen; Minghui; Yin; Lianjun; Zhou; Yaping; Xia; Jiankun; Liu; Yun; Zou

2017-01-01

Since mechanical loads exert a significant influence on the life span of wind turbines, the reduction of transient load on drive-train shaft has received more attention when implementing a maximum power point tracking(MPPT) controller.Moreover, a trade-off between the efficiency of wind energy extraction and the load level of drive-train shaft becomes a key issue. However, for the existing control strategies based on nonlinear model of wind turbines, the MPPT efficiencies are improved at the cost of the intensive fluctuation of generator torque and significant increase of transient load on drive train shaft. Hence, in this paper, a nonlinear controller with variable parameter is proposed for improving MPPT efficiency and mitigating transient load on drive-train simultaneously. Then,simulations on FAST(Fatigue, Aerodynamics, Structures, and Turbulence) code and experiments on the wind turbine simulator(WTS) based test bench are presented to verify the efficiency improvement of the proposed control strategy with less cost of drive-train load.

Variable Parameter Nonlinear Control for Maximum Power Point Tracking Considering Mitigation of Drive-train Load

Institute of Scientific and Technical Information of China (English)

Zaiyu Chen; Minghui Yin; Lianjun Zhou; Yaping Xia; Jiankun Liu; Yun Zou

2017-01-01

Since mechanical loads exert a significant influence on the life span of wind turbines,the reduction of transient load on drive-train shaft has received more attention when implementing a maximum power point tracking (MPPT) controller.Moreover,a trade-off between the efficiency of wind energy extraction and the load level of drive-train shaft becomes a key issue.However,for the existing control strategies based on nonlinear model of wind turbines,the MPPT efficiencies are improved at the cost of the intensive fluctuation of generator torque and significant increase of transient load on drive train shaft.Hence,in this paper,a nonlinear controller with variable parameter is proposed for improving MPPT efficiency and mitigating transient load on drive-train simultaneously.Then,simulations on FAST (Fatigue,Aerodynamics,Structures,and Turbulence) code and experiments on the wind turbine simulator (WTS) based test bench are presented to verify the efficiency improvement of the proposed control strategy with less cost of drive-train load.

Changes in Indirect Markers of Muscle Damage and Tendons After Daily Drop Jumping Exercise with Rapid Load Increase

Directory of Open Access Journals (Sweden)

Vidas Paleckis, Mantas Mickevičius, Audrius Snieckus, Vytautas Streckis, Mati Pääsuke, Saulius Rutkauskas, Rasa Steponavičiūtė, Albertas Skurvydas, Sigitas Kamandulis

2015-12-01

Full Text Available The aim of this study was to assess changes in indirect markers of muscle damage and type I collagen degradation, as well as, patellar and Achilles tendon morphological differences during nine daily drop-jumps sessions with constant load alternated with rapid increases in load to test the hypothesis that frequent drop-jump training results in negative muscular and tendon adaptation. Young men (n = 9 performed daily drop jump workouts with progression every 3 days in terms of number of jumps, platform height and squat amplitude. Voluntary and electrically evoked knee extensor torque, muscle soreness, blood plasma creatine kinase (CK activity and carboxyterminal cross-linked telopeptide (ICTP, patellar and Achilles tendon thickness and cross-sectional area (CSA were assessed at different time points during the training period and again on days 1, 3, 10 and 17 after the training. The findings were as follows: (1 steady decline in maximal muscle strength with major recovery within 24 hours after the first six daily training sessions; (2 larger decline in electrically induced muscle torque and prolonged recovery during last three training sessions; (3 increase in patellar and Achilles tendons CSA without change in thickness towards the end of training period; (4 increase in jump height but not in muscle strength after whole training period. Our findings suggest that frequent drop-jump sessions with constant load alternated with rapid increases in load do not induce severe muscle damage or major changes in tendons, nonetheless, this type of loading is not advisable for muscle strength improvement.

Daily Peak Load Forecasting Based on Complete Ensemble Empirical Mode Decomposition with Adaptive Noise and Support Vector Machine Optimized by Modified Grey Wolf Optimization Algorithm

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Shuyu Dai

2018-01-01

Full Text Available Daily peak load forecasting is an important part of power load forecasting. The accuracy of its prediction has great influence on the formulation of power generation plan, power grid dispatching, power grid operation and power supply reliability of power system. Therefore, it is of great significance to construct a suitable model to realize the accurate prediction of the daily peak load. A novel daily peak load forecasting model, CEEMDAN-MGWO-SVM (Complete Ensemble Empirical Mode Decomposition with Adaptive Noise and Support Vector Machine Optimized by Modified Grey Wolf Optimization Algorithm, is proposed in this paper. Firstly, the model uses the complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN algorithm to decompose the daily peak load sequence into multiple sub sequences. Then, the model of modified grey wolf optimization and support vector machine (MGWO-SVM is adopted to forecast the sub sequences. Finally, the forecasting sequence is reconstructed and the forecasting result is obtained. Using CEEMDAN can realize noise reduction for non-stationary daily peak load sequence, which makes the daily peak load sequence more regular. The model adopts the grey wolf optimization algorithm improved by introducing the population dynamic evolution operator and the nonlinear convergence factor to enhance the global search ability and avoid falling into the local optimum, which can better optimize the parameters of the SVM algorithm for improving the forecasting accuracy of daily peak load. In this paper, three cases are used to test the forecasting accuracy of the CEEMDAN-MGWO-SVM model. We choose the models EEMD-MGWO-SVM (Ensemble Empirical Mode Decomposition and Support Vector Machine Optimized by Modified Grey Wolf Optimization Algorithm, MGWO-SVM (Support Vector Machine Optimized by Modified Grey Wolf Optimization Algorithm, GWO-SVM (Support Vector Machine Optimized by Grey Wolf Optimization Algorithm, SVM (Support Vector

Comparative Study of Regional Estimation Methods for Daily Maximum Temperature (A Case Study of the Isfahan Province

Directory of Open Access Journals (Sweden)

Ghamar Fadavi

2016-02-01

Full Text Available Introduction: As the statistical time series are in short period and the meteorological station are not distributed well in mountainous area determining of climatic criteria are complex. Therefore, in recent years interpolation methods for establishment of continuous climatic data have been considered. Continuous daily maximum temperature data are a key factor for climate-crop modeling which is fundamental for water resources management, drought, and optimal use from climatic potentials of different regions. The main objective of this study is to evaluate different interpolation methods for estimation of regional maximum temperature in the Isfahan province. Materials and Methods: Isfahan province has about 937,105 square kilometers, between 30 degree and 43 minutes to 34 degree and 27 minutes North latitude equator line and 49 degree and 36 minutes to 55 degree and 31 minutes east longitude Greenwich. It is located in the center of Iran and it's western part extend to eastern footage of the Zagros mountain range. It should be mentioned that elevation range of meteorological stations are between 845 to 2490 in the study area. This study was done using daily maximum temperature data of 1992 and 2007 years of synoptic and climatology stations of I.R. of Iran meteorological organization (IRIMO. In order to interpolate temperature data, two years including 1992 and 2007 with different number of meteorological stations have been selected the temperature data of thirty meteorological stations (17 synoptic and 13 climatologically stations for 1992 year and fifty four meteorological stations (31 synoptic and 23 climatologically stations for 2007 year were used from Isfahan province and neighboring provinces. In order to regionalize the point data of daily maximum temperature, the interpolation methods, including inverse distance weighted (IDW, Kriging, Co-Kriging, Kriging-Regression, multiple regression and Spline were used. Therefore, for this allocated

Table for monthly average daily extraterrestrial irradiation on horizontal surface and the maximum possible sunshine duration

International Nuclear Information System (INIS)

Jain, P.C.

1984-01-01

The monthly average daily values of the extraterrestrial irradiation on a horizontal surface (H 0 ) and the maximum possible sunshine duration are two important parameters that are frequently needed in various solar energy applications. These are generally calculated by scientists each time they are needed and by using the approximate short-cut methods. Computations for these values have been made once and for all for latitude values of 60 deg. N to 60 deg. S at intervals of 1 deg. and are presented in a convenient tabular form. Values of the maximum possible sunshine duration as recorded on a Campbell Stoke's sunshine recorder are also computed and presented. These tables should avoid the need for repetition and approximate calculations and serve as a useful ready reference for solar energy scientists and engineers. (author)

A randomized controlled trial of vitamin D dosing strategies after acute hip fracture: No advantage of loading doses over daily supplementation

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Farrauto Leonardo

2011-06-01

Full Text Available Abstract Background There remains uncertainty regarding the appropriate therapeutic management of hip fracture patients. The primary aim of our study was to examine whether large loading doses in addition to daily vitamin D offered any advantage over a simple daily low-dose vitamin D regimen for increasing vitamin D levels. Methods In this randomized controlled study, patients over age 50 with an acute fragility hip fracture were enrolled from two hospital sites in Ontario, Canada. Participants were randomized to one of three loading dose groups: placebo; 50,000 IU vitamin D2; or 100,000 IU D2. Following a placebo/loading dose, all patients received a daily tablet of 1,000 IU vitamin D3 for 90 days. Serum 25-hydroxy vitamin D (25-OHD was measured at baseline, discharge from acute care (approximately 4-weeks, and 3-months. Results Sixty-five patients were enrolled in the study (44% male. An immediate rise in 25-OHD occurred in the 100,000 group, however there were no significant differences in 25-OHD between the placebo, 50,000 and 100,000 loading dose groups after 4-weeks (69.3, 84.5, 75.6 nmol/L, p = 0.15 and 3-months (86.7, 84.2, 73.3 nmol/L, p = 0.09, respectively. At the end of the study, approximately 75% of the placebo and 50,000 groups had reached the target therapeutic range (75 nmol/L, and 44% of the 100,000 group. Conclusions In correcting vitamin D insufficiency/deficiency in elderly patients with hip fracture, our findings suggest that starting with a lower daily dose of Vitamin D3 achieved similar results as providing an additional large loading dose of Vitamin D2. At the end of the study, all three groups were equally effective in attaining improvement in 25-OHD levels. Given that a daily dose of 1,000 IU vitamin D3 (with or without a loading dose resulted in at least 25% of patients having suboptimal vitamin D status, patients with acute hip fracture may benefit from a higher daily dose of vitamin D. Trial registration Clinical

Replacement of daily load attenuates but does not prevent changes to the musculoskeletal system during bed rest

Directory of Open Access Journals (Sweden)

Peter R. Cavanagh, PhD DSc

2016-12-01

Full Text Available The dose-response effects of exercise in reduced gravity on musculoskeletal health have not been well documented. It is not known whether or not individualized exercise prescriptions can be effective in preventing the substantial loss in bone mineral density and muscle function that have been observed in space flight and in bed rest. In this study, typical daily loads to the lower extremities were quantified in free-living subjects who were then randomly assigned to control or exercise groups. Subjects were confined to 6-degree head-down bed rest for 84 days. The exercise group performed individually prescribed 1 g loaded locomotor exercise to replace their free-living daily load. Eleven subjects (5 exercise, 6 control completed the protocol. Volumetric bone mineral density results from quantitative computed tomography demonstrated that control subjects lost significant amounts of bone in the intertrochanteric and total hip regions (p  0.0125. Pre-and post-bed rest muscle volumes were calculated from analysis of magnetic resonance imaging data. The exercise group retained a larger percentage of their total quadriceps and gastrocnemius muscle volume (−7.2% ± 5.9, −13.8% ± 6.1, respectively than their control counterparts (−23.3% ± 5.9, −33.0 ± 8.2, respectively; p  0.05. The decline in VO2max was 17% ± 18 in exercising subjects (p  0.05. In summary, the decline in a number of important measures of musculoskeletal and cardiovascular health was attenuated but not eliminated by a subject-specific program of locomotor exercise designed to replace daily load accumulated during free living. We conclude that single daily bouts of exposure to locomotor exercise can play a role in a countermeasures program during bed rest, and perhaps space flight, but are not sufficient in their own right to ensure musculoskeletal or cardiovascular health. Keywords: Space flight, Bed rest, Exercise, Biomechanics, Simulation, Gravity

Influence of Thread Root Radius on Maximum Local Stresses at Large Diameter Bolts under Axial Loading

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Cojocaru Vasile

2014-06-01

Full Text Available In the thread root area of the threaded bolts submitted to axial loading occur local stresses, higher that nominal stresses calculated for the bolts. These local stresses can generate failure and can reduce the fatigue life of the parts. The paper is focused on the study of the influence of the thread root radius on the maximum local stresses. A large diameter trapezoidal bolt was subjected to a static analysis (axial loading using finite element simulation.

Reliability of the Load-Velocity Relationship Obtained Through Linear and Polynomial Regression Models to Predict the One-Repetition Maximum Load.

Science.gov (United States)

Pestaña-Melero, Francisco Luis; Haff, G Gregory; Rojas, Francisco Javier; Pérez-Castilla, Alejandro; García-Ramos, Amador

2017-12-18

This study aimed to compare the between-session reliability of the load-velocity relationship between (1) linear vs. polynomial regression models, (2) concentric-only vs. eccentric-concentric bench press variants, as well as (3) the within-participants vs. the between-participants variability of the velocity attained at each percentage of the one-repetition maximum (%1RM). The load-velocity relationship of 30 men (age: 21.2±3.8 y; height: 1.78±0.07 m, body mass: 72.3±7.3 kg; bench press 1RM: 78.8±13.2 kg) were evaluated by means of linear and polynomial regression models in the concentric-only and eccentric-concentric bench press variants in a Smith Machine. Two sessions were performed with each bench press variant. The main findings were: (1) first-order-polynomials (CV: 4.39%-4.70%) provided the load-velocity relationship with higher reliability than second-order-polynomials (CV: 4.68%-5.04%); (2) the reliability of the load-velocity relationship did not differ between the concentric-only and eccentric-concentric bench press variants; (3) the within-participants variability of the velocity attained at each %1RM was markedly lower than the between-participants variability. Taken together, these results highlight that, regardless of the bench press variant considered, the individual determination of the load-velocity relationship by a linear regression model could be recommended to monitor and prescribe the relative load in the Smith machine bench press exercise.

Maximum attainable power density and wall load in tokamaks underlying reactor relevant constraints

International Nuclear Information System (INIS)

Borrass, K.; Buende, R.

1979-09-01

The characteristic data of tokamaks optimized with respect to their power density or wall load are determined. Reactor relevant constraints are imposed, such as a fixed plant net power output, a fixed blanket thickness and the dependence of the maximum toroidal field on the geometry and conductor material. The impact of finite burn times is considered. Various scaling laws of the toroidal beta with the aspect ratio are discussed. (orig.) 891 GG/orig. 892 RDG [de

Automatic Power Control for Daily Load-following Operation using Model Predictive Control Method

Energy Technology Data Exchange (ETDEWEB)

Yu, Keuk Jong; Kim, Han Gon [KH, Daejeon (Korea, Republic of)

2009-10-15

Under the circumstances that nuclear power occupies more than 50%, nuclear power plants are required to be operated on load-following operation in order to make the effective management of electric grid system and enhanced responsiveness to rapid changes in power demand. Conventional reactors such as the OPR1000 and APR1400 have a regulating system that controls the average temperature of the reactor core relation to the reference temperature. This conventional method has the advantages of proven technology and ease of implementation. However, this method is unsuitable for controlling the axial power shape, particularly the load following operation. Accordingly, this paper reports on the development of a model predictive control method which is able to control the reactor power and the axial shape index. The purpose of this study is to analyze the behavior of nuclear reactor power and the axial power shape by using a model predictive control method when the power is increased and decreased for a daily load following operation. The study confirms that deviations in the axial shape index (ASI) are within the operating limit.

Physical work load and psychological stress of daily activities as predictors of disability pension due to musculoskeletal disorders.

Science.gov (United States)

Ropponen, Annina; Svedberg, Pia; Koskenvuo, Markku; Silventoinen, Karri; Kaprio, Jaakko

2014-06-01

Physical work loading and psychological stress commonly co-occur in working life, hence potentially having an interrelationship that may affect work incapacity. This prospective cohort study aimed to investigate the effect of stability and change in physical work loading and stress on the risk of disability pension (DP) due to musculoskeletal diagnoses (MSD), while accounting for familial confounding in these associations. Data on 12,455 twins born before 1958 were surveyed of their physical work loading and psychological stress of daily activities in 1975 and 1981. The follow-up data was collected from pension registers until 2004. Cox proportional hazards regression models were used. During the follow up, 893 participants were granted DP due to MSD. Stable high (hazard ratio, HR, 2.21), but also increased physical work loading (HR 2.05) and high psychological stress (HR 2.22) were associated with increased risk for DP, and had significant interaction (p=0.032). The associations were confirmed when accounting for several confounding factors. Stable high but also increased physical work loading and psychological stress of daily activities between two timepoints with 6 years apart confirms their predictive role for an increased risk of DP. Both physical work loading and psychological stress seem to be independent from various confounding factors hence suggesting direct effect on risk for DP providing potential for occupational health care to early identification of persons at risk. © 2014 the Nordic Societies of Public Health.

Maximum thermal loading test of BWR fuel assembly

International Nuclear Information System (INIS)

Nakajima, Yoshitaka; Yoshimura, Kunihiro; Nakamura, Satoshi; Ishizuka, Takao.

1987-01-01

Various proving tests on the reliability of nuclear power plants have been conducted at the Nuclear Power Engineering Test Center and at the Japan Power Plant Engineering and Inspection Corporation. The tests were initiated at the request of the Ministry of International Trade and Industry (MITI). Toshiba undertook one of the proving tests on the reliability of nuclear fuel assembly; the maximum thermal loading test of BWR fuel assembly from the Nuclear Power Engineering Test Center. These tests are part of the proving tests mentioned above, and their purpose is to confirm the reliability of the thermal hydraulic engineering techniques. Toshiba has been engaged for the past nine years in the design, fabrication and testing of the equipment. For the project, a test model fuel assembly was used to measure the critical power of the BWR fuel assembly and the void and fluidity of the coolant. From the test results, it has been confirmed that the heat is transferred safely from the fuel assembly to the coolant in the BWR nuclear power plant. In addition, the propriety and reliability of the thermal hydraulic engineering techniques for the fuel assembly have been proved. (author)

Spatio-Temporal Convergence of Maximum Daily Light-Use Efficiency Based on Radiation Absorption by Canopy Chlorophyll

Science.gov (United States)

Zhang, Yao; Xiao, Xiangming; Wolf, Sebastian; Wu, Jin; Wu, Xiaocui; Gioli, Beniamino; Wohlfahrt, Georg; Cescatti, Alessandro; van der Tol, Christiaan; Zhou, Sha; Gough, Christopher M.; Gentine, Pierre; Zhang, Yongguang; Steinbrecher, Rainer; Ardö, Jonas

2018-04-01

Light-use efficiency (LUE), which quantifies the plants' efficiency in utilizing solar radiation for photosynthetic carbon fixation, is an important factor for gross primary production estimation. Here we use satellite-based solar-induced chlorophyll fluorescence as a proxy for photosynthetically active radiation absorbed by chlorophyll (APARchl) and derive an estimation of the fraction of APARchl (fPARchl) from four remotely sensed vegetation indicators. By comparing maximum LUE estimated at different scales from 127 eddy flux sites, we found that the maximum daily LUE based on PAR absorption by canopy chlorophyll (ɛmaxchl), unlike other expressions of LUE, tends to converge across biome types. The photosynthetic seasonality in tropical forests can also be tracked by the change of fPARchl, suggesting the corresponding ɛmaxchl to have less seasonal variation. This spatio-temporal convergence of LUE derived from fPARchl can be used to build simple but robust gross primary production models and to better constrain process-based models.

A Comparative Frequency Analysis of Maximum Daily Rainfall for a SE Asian Region under Current and Future Climate Conditions

Directory of Open Access Journals (Sweden)

Velautham Daksiya

2017-01-01

Full Text Available The impact of changing climate on the frequency of daily rainfall extremes in Jakarta, Indonesia, is analysed and quantified. The study used three different models to assess the changes in rainfall characteristics. The first method involves the use of the weather generator LARS-WG to quantify changes between historical and future daily rainfall maxima. The second approach consists of statistically downscaling general circulation model (GCM output based on historical empirical relationships between GCM output and station rainfall. Lastly, the study employed recent statistically downscaled global gridded rainfall projections to characterize climate change impact rainfall structure. Both annual and seasonal rainfall extremes are studied. The results show significant changes in annual maximum daily rainfall, with an average increase as high as 20% in the 100-year return period daily rainfall. The uncertainty arising from the use of different GCMs was found to be much larger than the uncertainty from the emission scenarios. Furthermore, the annual and wet seasonal analyses exhibit similar behaviors with increased future rainfall, but the dry season is not consistent across the models. The GCM uncertainty is larger in the dry season compared to annual and wet season.

Pressure transmission area and maximum pressure transmission of different thermoplastic resin denture base materials under impact load.

Science.gov (United States)

Nasution, Hubban; Kamonkhantikul, Krid; Arksornnukit, Mansuang; Takahashi, Hidekazu

2018-01-01

The purposes of the present study were to examine the pressure transmission area and maximum pressure transmission of thermoplastic resin denture base materials under an impact load, and to evaluate the modulus of elasticity and nanohardness of thermoplastic resin denture base. Three injection-molded thermoplastic resin denture base materials [polycarbonate (Basis PC), ethylene propylene (Duraflex), and polyamide (Valplast)] and one conventional heat-polymerized acrylic resin (PMMA, SR Triplex Hot) denture base, all with a mandibular first molar acrylic resin denture tooth set in were evaluated (n=6). Pressure transmission area and maximum pressure transmission of the specimens under an impact load were observed by using pressure-sensitive sheets. The modulus of elasticity and nanohardness of each denture base (n=10) were measured on 15×15×15×3mm 3 specimen by using an ultramicroindentation system. The pressure transmission area, modulus of elasticity, and nanohardness data were statistically analyzed with 1-way ANOVA, followed by Tamhane or Tukey HSD post hoc test (α=.05). The maximum pressure transmission data were statistically analyzed with Kruskal-Wallis H test, followed by Mann-Whitney U test (α=.05). Polymethyl methacrylate showed significantly larger pressure transmission area and higher maximum pressure transmission than the other groups (Pelasticity and nanohardness among the four types of denture bases (Pelasticity and nanohardness of each type of denture base were demonstrated. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

75 FR 26956 - Clean Water Act Section 303(d): Availability of Los Angeles Area Lakes Total Maximum Daily Loads...

Science.gov (United States)

2010-05-13

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9146-6] Clean Water Act Section 303(d): Availability of Los...: Notice of availability. SUMMARY: This action announces the availability of EPA proposed total maximum... nutrient, mercury, chlordane, dieldrin, DDT, PCB, and trash impairments pursuant to Clean Water Act Section...

Comfort air temperature influence on heating and cooling loads of a residential building

Science.gov (United States)

Stanciu, C.; Șoriga, I.; Gheorghian, A. T.; Stanciu, D.

2016-08-01

The paper presents the thermal behavior and energy loads of a two-level residential building designed for a family of four, two adults and two students, for different inside comfort levels reflected by the interior air temperature. Results are intended to emphasize the different thermal behavior of building elements and their contribution to the building's external load. The most important contributors to the building thermal loss are determined. Daily heating and cooling loads are computed for 12 months simulation in Bucharest (44.25°N latitude) in clear sky conditions. The most important aspects regarding sizing of thermal energy systems are emphasized, such as the reference months for maximum cooling and heating loads and these loads’ values. Annual maximum loads are encountered in February and August, respectively, so these months should be taken as reference for sizing thermal building systems, in Bucharest, under clear sky conditions.

Effects of squat lift training and free weight muscle training on maximum lifting load and isolinetic peak torque of young adults without impairments.

Science.gov (United States)

Yeung, S S; Ng, G Y

2000-06-01

Manual lifting is a frequent cause of back injury, and there is no evidence as to which training mode can provide the best training effect for lifting performance and muscle force. The purpose of this study was to examine the effects of a squat lift training and a free weight muscle training program on the maximum lifting load and isokinetic peak torque in subjects without known neuromuscular or musculoskeletal impairments. Thirty-six adults (20 male, 16 female) without known neuromuscular or musculoskeletal impairments participated. The subjects' mean age was 21.25 years (SD=1.16, range=20-24). Subjects were divided into 3 groups. Subjects in group 1 (n=12) performed squat lift training. Subjects in group 2 (n=12) participated in free weight resistance training of their shoulder abductors, elbow flexors, knee extensors and trunk extensors. Subjects in group 3 (n=12) served as controls. The maximum lifting load and isokinetic peak torques of the trunk extensors, knee extensors, elbow flexors, and shoulder abductors of each subject were measured before and after the study. Training was conducted on alternate days for 4 weeks, with an initial load of 80% of each subject's maximum capacity and with the load increased by 5% weekly. All groups were comparable for all measured variables before the study. After 4 weeks, subjects in groups 1 and 2 demonstrated more improvement in maximum lifting load and isokinetic peak torque of the back extensors compared with the subjects in group 3, but the 2 training groups were not different. The findings demonstrate that both squat lift and free weight resistance training are equally effective in improving the lifting load and isokinetic back extension performance of individuals without impairments.

Task 0715: Army Chesapeake Bay Total Maximum Daily Load Pilots

Science.gov (United States)

2011-05-01

NDCEE/CTC The NDCEE is operated by: Office of the Assistant Sec etary of the Army for Installations, E ergy and Enviro ment Technology Transition...stockpiles of soils and sands; – Air emissions with deposition potential; – Construction projects; – Existence of septic systems/sewage holding tanks

Clean Water Act Approved Total Maximum Daily Load (TMDL) Documents

Data.gov (United States)

U.S. Environmental Protection Agency — Information from Approved and Established TMDL Documents as well as TMDLs that have been Withdrawn. This includes the pollutants identified in the TMDL Document, the...

Utilization of small-angle neutron scattering to decide the maximum loading of nuclear waste in cement matrix

International Nuclear Information System (INIS)

Das, Avik; Mazumder, S.; Sen, D.; Yalmali, V.; Shah, J.G.

2014-01-01

Nuclear power plants generate many kinds of hazardous nuclear waste which are needed to be disposed in an eco-friendly manner. Many different waste incarceration techniques have been adapted for managing the nuclear waste of different category of radioactivity. Immobilisation of low and intermediate level radioactive wastes in cement matrix is one of the widely used and cost-effective techniques in waste management. However, loading of nuclear waste in cement matrix can alter the mesoscopic structure of the hydrated cement and hence, it is very important to set the maximum limit of waste loading in cement for providing proper physical isolation to the nuclear waste

Investigation of the Maximum Spin-Up Coefficients of Friction Obtained During Tests of a Landing Gear Having a Static-Load Rating of 20,000 Pounds

Science.gov (United States)

Batterson, Sidney A.

1959-01-01

An experimental investigation was made at the Langley landing loads track to obtain data on the maximum spin-up coefficients of friction developed by a landing gear having a static-load rating of 20,000 pounds. The forward speeds ranged from 0 to approximately 180 feet per second and the sinking speeds, from 2.7 feet per second to 9.4 feet per second. The results indicated the variation of the maximum spin-up coefficient of friction with forward speed and vertical load. Data obtained during this investigation are also compared with some results previously obtained for nonrolling tires to show the effect of forward speed.

Merging daily sea surface temperature data from multiple satellites using a Bayesian maximum entropy method

Science.gov (United States)

Tang, Shaolei; Yang, Xiaofeng; Dong, Di; Li, Ziwei

2015-12-01

Sea surface temperature (SST) is an important variable for understanding interactions between the ocean and the atmosphere. SST fusion is crucial for acquiring SST products of high spatial resolution and coverage. This study introduces a Bayesian maximum entropy (BME) method for blending daily SSTs from multiple satellite sensors. A new spatiotemporal covariance model of an SST field is built to integrate not only single-day SSTs but also time-adjacent SSTs. In addition, AVHRR 30-year SST climatology data are introduced as soft data at the estimation points to improve the accuracy of blended results within the BME framework. The merged SSTs, with a spatial resolution of 4 km and a temporal resolution of 24 hours, are produced in the Western Pacific Ocean region to demonstrate and evaluate the proposed methodology. Comparisons with in situ drifting buoy observations show that the merged SSTs are accurate and the bias and root-mean-square errors for the comparison are 0.15°C and 0.72°C, respectively.

Hierarchical Load Tracking Control of a Grid-connected Solid Oxide Fuel Cell for Maximum Electrical Efficiency Operation

DEFF Research Database (Denmark)

Li, Yonghui; Wu, Qiuwei; Zhu, Haiyu

2015-01-01

efficiency operation obtained at different active power output levels, a hierarchical load tracking control scheme for the grid-connected SOFC was proposed to realize the maximum electrical efficiency operation with the stack temperature bounded. The hierarchical control scheme consists of a fast active...... power control and a slower stack temperature control. The active power control was developed by using a decentralized control method. The efficiency of the proposed hierarchical control scheme was demonstrated by case studies using the benchmark SOFC dynamic model......Based on the benchmark solid oxide fuel cell (SOFC) dynamic model for power system studies and the analysis of the SOFC operating conditions, the nonlinear programming (NLP) optimization method was used to determine the maximum electrical efficiency of the grid-connected SOFC subject...

Improved Maximum Strength, Vertical Jump and Sprint Performance after 8 Weeks of Jump Squat Training with Individualized Loads

Science.gov (United States)

Marián, Vanderka; Katarína, Longová; Dávid, Olasz; Matúš, Krčmár; Simon, Walker

2016-01-01

The purpose of the study was to determine the effects of 8 weeks of jump squat training on isometric half squat maximal force production (Fmax) and rate of force development over 100ms (RFD100), countermovement jump (CMJ) and squat jump (SJ) height, and 50 m sprint time in moderately trained men. Sixty eight subjects (~21 years, ~180 cm, ~75 kg) were divided into experimental (EXP; n = 36) and control (CON, n = 32) groups. Tests were completed pre-, mid- and post-training. EXP performed jump squat training 3 times per week using loads that allowed all repetitions to be performed with ≥90% of maximum average power output (13 sessions with 4 sets of 8 repetitions and 13 sessions with 8 sets of 4 repetitions). Subjects were given real-time feedback for every repetition during the training sessions. Significant improvements in Fmax from pre- to mid- (Δ ~14%, psquats with loads that allow repetitions to be performed ≥90% of maximum average power output can simultaneously improve several different athletic performance tasks in the short-term. Key points Jump squat exercise is one of many exercises to develop explosive strength that has been the focus of several researches, while the load used during the training seem to be an important factor that affects training outcomes. Experimental group improved performance in all assessed parameters, such as Fmax, RFD100, CMJ, SJ and 50 m sprint time. However, improvements in CMJ and SJ were recorded after the entire power training period and thereafter plateau occurred. The portable FitroDyne could serve as a valuable device to individualize the load that maximizes mean power output and visual feedback can be provided to athletes during the training. PMID:27803628

Application of SVM methods for mid-term load forecasting

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Božić Miloš

2011-01-01

Full Text Available This paper presents an approach for the medium-term load forecasting using Support Vector Machines (SVMs. The proposed SVM model was employed to predict the maximum daily load demand for the period of a month. Analyses of available data were performed and the most important features for the construction of SVM model are selected. It was shown that the size and the structure of the training set may significantly affect the accuracy of predictions. The presented model was tested by applying it on real-life load data obtained from distribution company 'ED Jugoistok' for the territory of city Niš and its surroundings. Experimental results show that the proposed approach gives acceptable results for the entire period of prediction, which are in range with other solutions in this area.

Effect of error in crack length measurement on maximum load fracture toughness of Zr-2.5Nb pressure tube material

International Nuclear Information System (INIS)

Bind, A.K.; Sunil, Saurav; Singh, R.N.; Chakravartty, J.K.

2016-03-01

Recently it was found that maximum load toughness (J max ) for Zr-2.5Nb pressure tube material was practically unaffected by error in Δ a . To check the sensitivity of the J max to error in Δ a measurement, the J max was calculated assuming no crack growth up to the maximum load (P max ) for as received and hydrogen charged Zr-2.5Nb pressure tube material. For load up to the P max , the J values calculated assuming no crack growth (J NC ) were slightly higher than that calculated based on Δ a measured using DCPD technique (JDCPD). In general, error in the J calculation found to be increased exponentially with Δ a . The error in J max calculation was increased with an increase in Δ a and a decrease in J max . Based on deformation theory of J, an analytic criterion was developed to check the insensitivity of the J max to error in Δ a . There was very good linear relation was found between the J max calculated based on Δ a measured using DCPD technique and the J max calculated assuming no crack growth. This relation will be very useful to calculate J max without measuring the crack growth during fracture test especially for irradiated material. (author)

Impact of sampling strategy on stream load estimates in till landscape of the Midwest

Science.gov (United States)

Vidon, P.; Hubbard, L.E.; Soyeux, E.

2009-01-01

Accurately estimating various solute loads in streams during storms is critical to accurately determine maximum daily loads for regulatory purposes. This study investigates the impact of sampling strategy on solute load estimates in streams in the US Midwest. Three different solute types (nitrate, magnesium, and dissolved organic carbon (DOC)) and three sampling strategies are assessed. Regardless of the method, the average error on nitrate loads is higher than for magnesium or DOC loads, and all three methods generally underestimate DOC loads and overestimate magnesium loads. Increasing sampling frequency only slightly improves the accuracy of solute load estimates but generally improves the precision of load calculations. This type of investigation is critical for water management and environmental assessment so error on solute load calculations can be taken into account by landscape managers, and sampling strategies optimized as a function of monitoring objectives. ?? 2008 Springer Science+Business Media B.V.

Hierarchical Load Tracking Control of a Grid-Connected Solid Oxide Fuel Cell for Maximum Electrical Efficiency Operation

Directory of Open Access Journals (Sweden)

Yonghui Li

2015-03-01

Full Text Available Based on the benchmark solid oxide fuel cell (SOFC dynamic model for power system studies and the analysis of the SOFC operating conditions, the nonlinear programming (NLP optimization method was used to determine the maximum electrical efficiency of the grid-connected SOFC subject to the constraints of fuel utilization factor, stack temperature and output active power. The optimal operating conditions of the grid-connected SOFC were obtained by solving the NLP problem considering the power consumed by the air compressor. With the optimal operating conditions of the SOFC for the maximum efficiency operation obtained at different active power output levels, a hierarchical load tracking control scheme for the grid-connected SOFC was proposed to realize the maximum electrical efficiency operation with the stack temperature bounded. The hierarchical control scheme consists of a fast active power control and a slower stack temperature control. The active power control was developed by using a decentralized control method. The efficiency of the proposed hierarchical control scheme was demonstrated by case studies using the benchmark SOFC dynamic model.

Total maximum allocated load calculation of nitrogen pollutants by linking a 3D biogeochemical-hydrodynamic model with a programming model in Bohai Sea

Science.gov (United States)

Dai, Aiquan; Li, Keqiang; Ding, Dongsheng; Li, Yan; Liang, Shengkang; Li, Yanbin; Su, Ying; Wang, Xiulin

2015-12-01

The equal percent removal (EPR) method, in which pollutant reduction ratio was set as the same in all administrative regions, failed to satisfy the requirement for water quality improvement in the Bohai Sea. Such requirement was imposed by the developed Coastal Pollution Total Load Control Management. The total maximum allocated load (TMAL) of nitrogen pollutants in the sea-sink source regions (SSRs) around the Bohai Rim, which is the maximum pollutant load of every outlet under the limitation of water quality criteria, was estimated by optimization-simulation method (OSM) combined with loop approximation calculation. In OSM, water quality is simulated using a water quality model and pollutant load is calculated with a programming model. The effect of changes in pollutant loads on TMAL was discussed. Results showed that the TMAL of nitrogen pollutants in 34 SSRs was 1.49×105 ton/year. The highest TMAL was observed in summer, whereas the lowest in winter. TMAL was also higher in the Bohai Strait and central Bohai Sea and lower in the inner area of the Liaodong Bay, Bohai Bay and Laizhou Bay. In loop approximation calculation, the TMAL obtained was considered satisfactory for water quality criteria as fluctuation of concentration response matrix with pollutant loads was eliminated. Results of numerical experiment further showed that water quality improved faster and were more evident under TMAL input than that when using the EPR method

Willingness to Pay Survey for Chesapeake Bay Total Maximum Daily Load

Science.gov (United States)

A stated preference survey to collect data on households’ use of Chesapeake Bay and its watershed, and of their preferences for a variety of water quality improvements likely to follow from pollution reduction programs.

Climate Prediction Center (CPC) U.S. Daily Maximum Air Temperature Observations

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National Oceanic and Atmospheric Administration, Department of Commerce — Observational reports of daily air temperature (1200 UTC to 1200 UTC) are made by members of the NWS Automated Surface Observing Systems (ASOS) network; NWS...

Using the Enhanced Daily Load Stimulus Model to Quantify the Mechanical Load and Bone Mineral Density Changes Experienced by Crew Members on the International Space Station

Science.gov (United States)

Genc, K. O.; Gopalakrishnan, R.; Kuklis, M. M.; Maender, C. C.; Rice, A. J.; Cavanagh, P. R.

2009-01-01

Despite the use of exercise countermeasures during long-duration space missions, bone mineral density (BMD) and predicted bone strength of astronauts continue to show decreases in the lower extremities and spine. This site-specific bone adaptation is most likely caused by the effects of microgravity on the mechanical loading environment of the crew member. There is, therefore, a need to quantify the mechanical loading experienced on Earth and on-orbit to define the effect of a given "dose" of loading on bone homeostasis. Gene et al. recently proposed an enhanced DLS (EDLS) model that, when used with entire days of in-shoe forces, takes into account recently developed theories on the importance of factors such as saturation, recovery, and standing and their effects on the osteogenic response of bone to daily physical activity. This algorithm can also quantify the tinting and type of activity (sit/unload, stand, walk, run or other loaded activity) performed throughout the day. The purpose of the current study was to use in-shoe force measurements from entire typical work days on Earth and on-orbit in order to quantify the type and amount of loading experienced by crew members. The specific aim was to use these measurements as inputs into the EDLS model to determine activity timing/type and the mechanical "dose" imparted on the musculoskeletal system of crew members and relate this dose to changes in bone homeostasis.

ANALYSIS OF THE STATISTICAL BEHAVIOUR OF DAILY MAXIMUM AND MONTHLY AVERAGE RAINFALL ALONG WITH RAINY DAYS VARIATION IN SYLHET, BANGLADESH

Directory of Open Access Journals (Sweden)

G. M. J. HASAN

2014-10-01

Full Text Available Climate, one of the major controlling factors for well-being of the inhabitants in the world, has been changing in accordance with the natural forcing and manmade activities. Bangladesh, the most densely populated countries in the world is under threat due to climate change caused by excessive use or abuse of ecology and natural resources. This study checks the rainfall patterns and their associated changes in the north-eastern part of Bangladesh mainly Sylhet city through statistical analysis of daily rainfall data during the period of 1957 - 2006. It has been observed that a good correlation exists between the monthly mean and daily maximum rainfall. A linear regression analysis of the data is found to be significant for all the months. Some key statistical parameters like the mean values of Coefficient of Variability (CV, Relative Variability (RV and Percentage Inter-annual Variability (PIV have been studied and found to be at variance. Monthly, yearly and seasonal variation of rainy days also analysed to check for any significant changes.

Review of revised Klamath River Total Maximum Daily Load models from Link River Dam to Keno Dam, Oregon

Science.gov (United States)

Rounds, Stewart A.; Sullivan, Annett B.

2013-01-01

Flow and water-quality models are being used to support the development of Total Maximum Daily Load (TMDL) plans for the Klamath River downstream of Upper Klamath Lake (UKL) in south-central Oregon. For riverine reaches, the RMA-2 and RMA-11 models were used, whereas the CE-QUAL-W2 model was used to simulate pooled reaches. The U.S. Geological Survey (USGS) was asked to review the most upstream of these models, from Link River Dam at the outlet of UKL downstream through the first pooled reach of the Klamath River from Lake Ewauna to Keno Dam. Previous versions of these models were reviewed in 2009 by USGS. Since that time, important revisions were made to correct several problems and address other issues. This review documents an assessment of the revised models, with emphasis on the model revisions and any remaining issues. The primary focus of this review is the 19.7-mile Lake Ewauna to Keno Dam reach of the Klamath River that was simulated with the CE-QUAL-W2 model. Water spends far more time in the Lake Ewauna to Keno Dam reach than in the 1-mile Link River reach that connects UKL to the Klamath River, and most of the critical reactions affecting water quality upstream of Keno Dam occur in that pooled reach. This model review includes assessments of years 2000 and 2002 current conditions scenarios, which were used to calibrate the model, as well as a natural conditions scenario that was used as the reference condition for the TMDL and was based on the 2000 flow conditions. The natural conditions scenario included the removal of Keno Dam, restoration of the Keno reef (a shallow spot that was removed when the dam was built), removal of all point-source inputs, and derivation of upstream boundary water-quality inputs from a previously developed UKL TMDL model. This review examined the details of the models, including model algorithms, parameter values, and boundary conditions; the review did not assess the draft Klamath River TMDL or the TMDL allocations

Evaluation of daily maximum and minimum 2-m temperatures as simulated with the Regional Climate Model COSMO-CLM over Africa

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Stefan Krähenmann

2013-07-01

Full Text Available The representation of the diurnal 2-m temperature cycle is challenging because of the many processes involved, particularly land-atmosphere interactions. This study examines the ability of the regional climate model COSMO-CLM (version 4.8 to capture the statistics of daily maximum and minimum 2-m temperatures (Tmin/Tmax over Africa. The simulations are carried out at two different horizontal grid-spacings (0.22° and 0.44°, and are driven by ECMWF ERA-Interim reanalyses as near-perfect lateral boundary conditions. As evaluation reference, a high-resolution gridded dataset of daily maximum and minimum temperatures (Tmin/Tmax for Africa (covering the period 2008–2010 is created using the regression-kriging-regression-kriging (RKRK algorithm. RKRK applies, among other predictors, the remotely sensed predictors land surface temperature and cloud cover to compensate for the missing information about the temperature pattern due to the low station density over Africa. This dataset allows the evaluation of temperature characteristics like the frequencies of Tmin/Tmax, the diurnal temperature range, and the 90th percentile of Tmax. Although the large-scale patterns of temperature are reproduced well, COSMO-CLM shows significant under- and overestimation of temperature at regional scales. The hemispheric summers are generally too warm and the day-to-day temperature variability is overestimated over northern and southern extra-tropical Africa. The average diurnal temperature range is underestimated by about 2°C across arid areas, yet overestimated by around 2°C over the African tropics. An evaluation based on frequency distributions shows good model performance for simulated Tmin (the simulated frequency distributions capture more than 80% of the observed ones, but less well performance for Tmax (capture below 70%. Further, over wide parts of Africa a too large fraction of daily Tmax values exceeds the observed 90th percentile of Tmax, particularly

Evaluation of daily maximum and minimum 2-m temperatures as simulated with the regional climate model COSMO-CLM over Africa

Energy Technology Data Exchange (ETDEWEB)

Kraehenmann, Stefan; Kothe, Steffen; Ahrens, Bodo [Frankfurt Univ. (Germany). Inst. for Atmospheric and Environmental Sciences; Panitz, Hans-Juergen [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany)

2013-10-15

The representation of the diurnal 2-m temperature cycle is challenging because of the many processes involved, particularly land-atmosphere interactions. This study examines the ability of the regional climate model COSMO-CLM (version 4.8) to capture the statistics of daily maximum and minimum 2-m temperatures (Tmin/Tmax) over Africa. The simulations are carried out at two different horizontal grid-spacings (0.22 and 0.44 ), and are driven by ECMWF ERA-Interim reanalyses as near-perfect lateral boundary conditions. As evaluation reference, a high-resolution gridded dataset of daily maximum and minimum temperatures (Tmin/Tmax) for Africa (covering the period 2008-2010) is created using the regression-kriging-regression-kriging (RKRK) algorithm. RKRK applies, among other predictors, the remotely sensed predictors land surface temperature and cloud cover to compensate for the missing information about the temperature pattern due to the low station density over Africa. This dataset allows the evaluation of temperature characteristics like the frequencies of Tmin/Tmax, the diurnal temperature range, and the 90{sup th} percentile of Tmax. Although the large-scale patterns of temperature are reproduced well, COSMO-CLM shows significant under- and overestimation of temperature at regional scales. The hemispheric summers are generally too warm and the day-to-day temperature variability is overestimated over northern and southern extra-tropical Africa. The average diurnal temperature range is underestimated by about 2 C across arid areas, yet overestimated by around 2 C over the African tropics. An evaluation based on frequency distributions shows good model performance for simulated Tmin (the simulated frequency distributions capture more than 80% of the observed ones), but less well performance for Tmax (capture below 70%). Further, over wide parts of Africa a too large fraction of daily Tmax values exceeds the observed 90{sup th} percentile of Tmax, particularly across

Statistical analysis of yearly series of maximum daily rainfall in Spain. Analisis estadistico de las series anuales de maximas lluvias diarias en Espaa

Energy Technology Data Exchange (ETDEWEB)

Ferrer Polo, J.; Ardiles Lopez, K. L. (CEDEX, Ministerio de Obras Publicas, Transportes y Medio ambiente, Madrid (Spain))

1994-01-01

Work on the statistical modelling of maximum daily rainfalls is presented, with a view to estimating the quantiles for different return periods. An index flood approach has been adopted in which the local quantiles are a result of rescaling a regional law using the mean of each series of values, that is utilized as a local scale factor. The annual maximum series have been taken from 1.545 meteorological stations over a 30 year period, and these have been classified into 26 regions defined according to meteorological criteria, the homogeneity of wich has been checked by means of a statistical analysis of the coefficients of variation of the samples,using the. An estimation has been made of the parameters for the following four distribution models: Two Component Extreme Value (TCEV); General Extreme Value (GEV); Log-Pearson III (LP3); and SQRT-Exponential Type Distribution of Maximum. The analysis of the quantiles obtained reveals slight differences in the results thus detracting from the importance of the model selection. The last of the above-mentioned distribution has been finally chosen, on the basis of the following: it is defined with fewer parameters it is the only that was proposed specifically for the analysis of daily rainfall maximums; it yields more conservative results than the traditional Gumbel distribution for the high return periods; and it is capable of providing a good description of the main sampling statistics concerning the right-hand tail of the distribution, a fact that has been checked with Montecarlo's simulation techniques. The choice of a distribution model with only two parameters has led to the selection of the regional coefficient of variation as the only determining parameter for the regional quantiles. This has permitted the elimination of the quantiles discontinuity of the classical regional approach, thus smoothing the values of that coefficient by means of an isoline plan on a national scale.

Maximum power output and load matching of a phosphoric acid fuel cell-thermoelectric generator hybrid system

Science.gov (United States)

Chen, Xiaohang; Wang, Yuan; Cai, Ling; Zhou, Yinghui

2015-10-01

Based on the current models of phosphoric acid fuel cells (PAFCs) and thermoelectric generators (TGs), a new hybrid system is proposed, in which the effects of multi-irreversibilities resulting from the activation, concentration, and ohmic overpotentials in the PAFC, Joule heat and heat leak in the TG, finite-rate heat transfer between the TG and the heat reservoirs, and heat leak from the PAFC to the environment are taken into account. Expressions for the power output and efficiency of the PAFC, TG, and hybrid system are analytically derived and directly used to discuss the performance characteristics of the hybrid system. The optimal relationship between the electric currents in the PAFC and TG is obtained. The maximum power output is numerically calculated. It is found that the maximum power output density of the hybrid system will increase about 150 Wm-2, compared with that of a single PAFC. The problem how to optimally match the load resistances of two subsystems is discussed. Some significant results for practical hybrid systems are obtained.

The Reliability of Individualized Load-Velocity Profiles.

Science.gov (United States)

Banyard, Harry G; Nosaka, K; Vernon, Alex D; Haff, G Gregory

2017-11-15

This study examined the reliability of peak velocity (PV), mean propulsive velocity (MPV), and mean velocity (MV) in the development of load-velocity profiles (LVP) in the full depth free-weight back squat performed with maximal concentric effort. Eighteen resistance-trained men performed a baseline one-repetition maximum (1RM) back squat trial and three subsequent 1RM trials used for reliability analyses, with 48-hours interval between trials. 1RM trials comprised lifts from six relative loads including 20, 40, 60, 80, 90, and 100% 1RM. Individualized LVPs for PV, MPV, or MV were derived from loads that were highly reliable based on the following criteria: intra-class correlation coefficient (ICC) >0.70, coefficient of variation (CV) ≤10%, and Cohen's d effect size (ES) 0.05) between trials, movement velocities, or between linear regression versus second order polynomial fits. PV 20-100% , MPV 20-90% , and MV 20-90% are reliable and can be utilized to develop LVPs using linear regression. Conceptually, LVPs can be used to monitor changes in movement velocity and employed as a method for adjusting sessional training loads according to daily readiness.

Impact of sampling resolution on estimation of community-wide daily illicit drug use

DEFF Research Database (Denmark)

Ramin, Pedram; Baz Lomba, J. A.; Reid, M.

It is a common approach to report daily community-wide drug consumption, based on single daily measurements of the influent from a treatment plant. This article suggests that neglecting diurnal variations of loads and flow can result in misestimating daily drug consumption.......It is a common approach to report daily community-wide drug consumption, based on single daily measurements of the influent from a treatment plant. This article suggests that neglecting diurnal variations of loads and flow can result in misestimating daily drug consumption....

Plastic limit loads for cylindrical shell intersections under combined loading

International Nuclear Information System (INIS)

Skopinsky, V.N.; Berkov, N.A.; Vogov, R.A.

2015-01-01

In this research, applied methods of nonlinear analysis and results of determining the plastic limit loads for shell intersection configurations under combined internal pressure, in-plane moment and out-plane moment loadings are presented. The numerical analysis of shell intersections is performed using the finite element method, geometrically nonlinear shell theory in quadratic approximation and plasticity theory. For determining the load parameter of proportional combined loading, the developed maximum criterion of rate of change of relative plastic work is employed. The graphical results for model of cylindrical shell intersection under different two-parameter combined loadings (as generalized plastic limit load curves) and three-parameter combined loading (as generalized plastic limit load surface) are presented on the assumption that the internal pressure, in-plane moment and out-plane moment loads were applied in a proportional manner. - Highlights: • This paper presents nonlinear two-dimensional FE analysis for shell intersections. • Determining the plastic limit loads under combined loading is considered. • Developed maximum criterion of rate of change of relative plastic work is employed. • Plastic deformation mechanism in shell intersections is discussed. • Results for generalized plastic limit load curves of branch intersection are presented

Climate Prediction Center (CPC) US daily temperature analyses

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. daily temperature analyses are maps depicting various temperature quantities utilizing daily maximum and minimum temperature data across the US. Maps are...

Formulation of Forming Load in V-Bending

Directory of Open Access Journals (Sweden)

Koumura Yuki

2016-01-01

Full Text Available A novel method is described to calculate the forming load in V-bending by a press brake. The data of forming load are collected by FEM analysis. With an increase of the punch stroke in V-bending, the forming load increases gradually after the elastic limit, and then decreases after showing the maximum value. The proposal formulation to trace the variations in the forming load curve includes the calculating method of the load of the elastic limit, the maximum load in air bending and the variations of the forming load before/after the bending stroke of the maximum load. The calculated precision is confirmed by comparing with the measured load-stroke curves in V-bending with a press brake.

Annual suspended-sediment loads in the Colorado River near Cisco, Utah, 1930-82

Science.gov (United States)

Thompson, K.R.

1985-01-01

The Colorado River upstream of gaging station 09180500 near Cisco, Utah, drains about 24,100 square miles in Utah and Colorado. Altitudes in the basin range from 12,480 feet near the headwaters to 4,090 feet at station 09180500. The average annual precipitation for 1894-1982 near the station was 7.94 inches. The average annual precipitation near the headwaters often exceeds 50 inches. Rocks ranging in age from Precambrian to Holocene are exposed in the drainage basin upstream from station 09180500. Shale, limestone, siltstone, mudstone, and sandstone probably are the most easily eroded rocks in the basin, and they contribute large quantities of sediment to the Colorado River. During 1930-82, the U.S. Geological Survey collected records of fluvial sediment at station 09180500. Based on these records, the mean annual suspended-sediment load was 11,390,000 tone, ranging from 2,038,000 tons in water year 1981 to 35,700,000 tons in water year 1938. The minimum daily load of 14 tons was on August 22, 1960, and the maximum daily load of 2,790,000 tons was on October 14, 1941. (USGS)

Synchronized Pulsed dc - dc Converter as Maximum Power Position Tracker with Wide Load and Insolation Variation for Stand Alone PV System

International Nuclear Information System (INIS)

Hardik, P. Desai; Ranjan Maheshwari

2011-01-01

This paper investigates the interest focused on employing parallel connected dc-dc converter with high tracking effectiveness under wide variation in environmental conditions (Insolation) and wide load variation. dc-dc converter is an essential part of the stand alone PV system. Paper also presents an approach on how duty cycle for maximum power position (MPP) is adjusted by taking care of varying load conditions and without iterative steps. Synchronized PWM pulses are employed for the converter. High tracking efficiency is achieved with continuous input and inductor current. In this approach, the converter can he utilized in buck as well in boost mode. The PV system simulation was verified and experimental results were in agreement to the presented scheme. (authors)

Estimation of daily maximum and minimum air temperatures in urban landscapes using MODIS time series satellite data

Science.gov (United States)

Yoo, Cheolhee; Im, Jungho; Park, Seonyoung; Quackenbush, Lindi J.

2018-03-01

Urban air temperature is considered a significant variable for a variety of urban issues, and analyzing the spatial patterns of air temperature is important for urban planning and management. However, insufficient weather stations limit accurate spatial representation of temperature within a heterogeneous city. This study used a random forest machine learning approach to estimate daily maximum and minimum air temperatures (Tmax and Tmin) for two megacities with different climate characteristics: Los Angeles, USA, and Seoul, South Korea. This study used eight time-series land surface temperature (LST) data from Moderate Resolution Imaging Spectroradiometer (MODIS), with seven auxiliary variables: elevation, solar radiation, normalized difference vegetation index, latitude, longitude, aspect, and the percentage of impervious area. We found different relationships between the eight time-series LSTs with Tmax/Tmin for the two cities, and designed eight schemes with different input LST variables. The schemes were evaluated using the coefficient of determination (R2) and Root Mean Square Error (RMSE) from 10-fold cross-validation. The best schemes produced R2 of 0.850 and 0.777 and RMSE of 1.7 °C and 1.2 °C for Tmax and Tmin in Los Angeles, and R2 of 0.728 and 0.767 and RMSE of 1.1 °C and 1.2 °C for Tmax and Tmin in Seoul, respectively. LSTs obtained the day before were crucial for estimating daily urban air temperature. Estimated air temperature patterns showed that Tmax was highly dependent on the geographic factors (e.g., sea breeze, mountains) of the two cities, while Tmin showed marginally distinct temperature differences between built-up and vegetated areas in the two cities.

Microprocessor-controlled step-down maximum-power-point tracker for photovoltaic systems

Science.gov (United States)

Mazmuder, R. K.; Haidar, S.

1992-12-01

An efficient maximum power point tracker (MPPT) has been developed and can be used with a photovoltaic (PV) array and a load which requires lower voltage than the PV array voltage to be operated. The MPPT makes the PV array to operate at maximum power point (MPP) under all insolation and temperature, which ensures the maximum amount of available PV power to be delivered to the load. The performance of the MPPT has been studied under different insolation levels.

Mapping Daily and Maximum Flood Extents at 90-m Resolution During Hurricanes Harvey and Irma Using Passive Microwave Remote Sensing

Science.gov (United States)

Galantowicz, J. F.; Picton, J.; Root, B.

2017-12-01

Passive microwave remote sensing can provided a distinct perspective on flood events by virtue of wide sensor fields of view, frequent observations from multiple satellites, and sensitivity through clouds and vegetation. During Hurricanes Harvey and Irma, we used AMSR2 (Advanced Microwave Scanning Radiometer 2, JAXA) data to map flood extents starting from the first post-storm rain-free sensor passes. Our standard flood mapping algorithm (FloodScan) derives flooded fraction from 22-km microwave data (AMSR2 or NASA's GMI) in near real time and downscales it to 90-m resolution using a database built from topography, hydrology, and Global Surface Water Explorer data and normalized to microwave data footprint shapes. During Harvey and Irma we tested experimental versions of the algorithm designed to map the maximum post-storm flood extent rapidly and made a variety of map products available immediately for use in storm monitoring and response. The maps have several unique features including spanning the entire storm-affected area and providing multiple post-storm updates as flood water shifted and receded. From the daily maps we derived secondary products such as flood duration, maximum flood extent (Figure 1), and flood depth. In this presentation, we describe flood extent evolution, maximum extent, and local details as detected by the FloodScan algorithm in the wake of Harvey and Irma. We compare FloodScan results to other available flood mapping resources, note observed shortcomings, and describe improvements made in response. We also discuss how best-estimate maps could be updated in near real time by merging FloodScan products and data from other remote sensing systems and hydrological models.

Optimization Formulations for the Maximum Nonlinear Buckling Load of Composite Structures

DEFF Research Database (Denmark)

Lindgaard, Esben; Lund, Erik

2011-01-01

This paper focuses on criterion functions for gradient based optimization of the buckling load of laminated composite structures considering different types of buckling behaviour. A local criterion is developed, and is, together with a range of local and global criterion functions from literature......, benchmarked on a number of numerical examples of laminated composite structures for the maximization of the buckling load considering fiber angle design variables. The optimization formulations are based on either linear or geometrically nonlinear analysis and formulated as mathematical programming problems...... solved using gradient based techniques. The developed local criterion is formulated such it captures nonlinear effects upon loading and proves useful for both analysis purposes and as a criterion for use in nonlinear buckling optimization. © 2010 Springer-Verlag....

Bone healing response in cyclically loaded implants: Comparing zero, one, and two loading sessions per day.

Science.gov (United States)

de Barros E Lima Bueno, Renan; Dias, Ana Paula; Ponce, Katia J; Wazen, Rima; Brunski, John B; Nanci, Antonio

2018-05-31

When bone implants are loaded, they are inevitably subjected to displacement relative to bone. Such micromotion generates stress/strain states at the interface that can cause beneficial or detrimental sequels. The objective of this study is to better understand the mechanobiology of bone healing at the tissue-implant interface during repeated loading. Machined screw shaped Ti implants were placed in rat tibiae in a hole slightly bigger than the implant diameter. Implants were held stable by a specially-designed bone plate that permits controlled loading. Three loading regimens were applied, (a) zero loading, (b) one daily loading session of 60 cycles with an axial force of 1.5 N/cycle for 7 days, and (c) two such daily sessions with the same axial force also for 7 days. Finite element analysis was used to characterize the mechanobiological conditions produced by the loading sessions. After 7 days, the implants with surrounding interfacial tissue were harvested and processed for histological, histomorphometric and DNA microarray analyses. Histomorphometric analyses revealed that the group subjected to repeated loading sessions exhibited a significant decrease in bone-implant contact and increase in bone-implant distance, as compared to unloaded implants and those subjected to only one loading session. Gene expression profiles differed during osseointegration between all groups mainly with respect to inflammatory and unidentified gene categories. The results indicate that increasing the daily cyclic loading of implants induces deleterious changes in the bone healing response, most likely due to the accumulation of tissue damage and associated inflammatory reaction at the bone-implant interface. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Load following operation of nuclear power plants for meeting power system requirements

International Nuclear Information System (INIS)

Isoda, Hachiro

1987-01-01

This paper describes a calculating program on the availability factors of nuclear, thermal and pumed storage hydro power stations and some calculated results for typical three load factors, 55 %, 60 % and 71 %, are provided when the share of the nuclea power station in the generation facilities is increased. The load following requirement of the nuclear power station is also provided. Load following requirement: If there is a 10 % pumped storage hydro power station, the nuclear power station enables to be operated with its rated output up to 30 % - 35 % of its share. Its daily load following operation for 40 % and 50 % nuclear power station needs every weekend and every day respectively. Availability factor: The availability factor of the nuclear power station manages to get 80 % (maximum availability factor of the nuclear power station in this study) up to 30 % share of it with 10 % pumpued storage hydro power station. When the nuclear power station shares 40 % and 50 %, its availability factor decreases down 1 % and 5 % respectively. (author)

Local Times of Galactic Cosmic Ray Intensity Maximum and Minimum in the Diurnal Variation

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Su Yeon Oh

2006-06-01

Full Text Available The Diurnal variation of galactic cosmic ray (GCR flux intensity observed by the ground Neutron Monitor (NM shows a sinusoidal pattern with the amplitude of 1sim 2 % of daily mean. We carried out a statistical study on tendencies of the local times of GCR intensity daily maximum and minimum. To test the influences of the solar activity and the location (cut-off rigidity on the distribution in the local times of maximum and minimum GCR intensity, we have examined the data of 1996 (solar minimum and 2000 (solar maximum at the low-latitude Haleakala (latitude: 20.72 N, cut-off rigidity: 12.91 GeV and the high-latitude Oulu (latitude: 65.05 N, cut-off rigidity: 0.81 GeV NM stations. The most frequent local times of the GCR intensity daily maximum and minimum come later about 2sim3 hours in the solar activity maximum year 2000 than in the solar activity minimum year 1996. Oulu NM station whose cut-off rigidity is smaller has the most frequent local times of the GCR intensity maximum and minimum later by 2sim3 hours from those of Haleakala station. This feature is more evident at the solar maximum. The phase of the daily variation in GCR is dependent upon the interplanetary magnetic field varying with the solar activity and the cut-off rigidity varying with the geographic latitude.

DYNAMIC TIME HISTORY ANALYSIS OF BLAST RESISTANT DOOR USING BLAST LOAD MODELED AS IMPACT LOAD

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Y. A. Pranata

2012-06-01

Full Text Available A blast resistant single door was designed to withstand a 0.91 bar blast pressure and 44 ms blast duration. The analysis was done using Dynamic Time History Analysis using Blast Load modeled as Impact Load for given duration. The material properties used have been modified to accommodate dynamic effects. The analysis was done using dynamic finite element method (fem for time of the blast duration, and the maximum/minimum internal forces and displacement were taken from the time history output, in order to know the behavior under blast load and estimate the safety margin of the door. Results obtained from this research indicated that the maximum z-displacement is 1.709 mm, while in the term of serviceability, the permitted is 25 mm. The maximum reaction force is 73,960 N, while the maximum anchor capacity is 82,069 N. On blast condition, the maximum frame stress is 71.71 MPa, the maximum hinge shear stress is 45.28 MPa. While on rebound condition, the maximum frame stress is 172.11 MPa, the maximum hinge shear stress is 29.46 MPa. The maximum door edge rotation is 0.44 degree, which is not exceed the permitted boundary (1.2 degree. Keywords: Dynamic time history, blast resistant door, single door, finite element method.

Aplicação do método da carga máxima total diária (CMTD para a amônia no Rio Atibaia, região de Campinas/Paulínia - SP Application of ammonia total maximum daily load (TMDL to Atibaia River, Campinas/Paulínia region - São Paulo state

Directory of Open Access Journals (Sweden)

Gilberto Silvério da Silva

2007-06-01

Full Text Available Neste estudo foram avaliadas a capacidade de suporte e o estado de degradação do Rio Atibaia, considerando a ameaça para a vida aquática pela presença da Amônia, a qual representa um dos principais riscos às comunidades aquáticas no Rio Atibaia. Com este objetivo foi aplicado o método da Carga Máxima Total Diária (CMTD, da Agência de Proteção Ambiental dos Estados Unidos (EPA. Os resultados revelaram que as cargas de Amônia aumentavam progressivamente ao longo do Rio Atibaia, principalmente devido às fontes pontuais. As cargas de Amônia diárias assumiram valores de 30 a 5000 kg NH3. A capacidade de suporte das águas Rio Atibaia, para proteger a vida aquática contra os efeitos tóxicos da Amônia, tem sido violadas em trechos próximos à sua foz. A degradação dessas águas foi mais intensa na estação seca. Este trabalho mostrou que o esgoto doméstico não-tratado de uma população aproximada de 250 mil habitantes da cidade de Campinas, via Ribeirão Anhumas, é a principal fonte de Amônia na bacia do Rio Atibaia, apesar do grande número de indústrias ali presentes.This study evaluated the tolerance capacity and the impairment state of the Atibaia River, considering the threat to aquatic life by the presence of Ammonia, which represents one of the main risks to the aquatic communities in the Atibaia River. With this aim, the method Total Maximum Daily Load (TMDL, from the United States Environmental Protection Agency (EPA, was applied. The results revealed that the Ammonia loads increased progressively through the Atibaia River, especially due to the point sources. The daily Ammonia loads assumed values that ranged from 30 to 5000 kg NH3. The tolerance capacity of the waters of the Atibaia River, to protect aquatic life against the toxic effects of the Ammonia, has been violated in reaches near its mouth. The impairment of these waters was more intense during the dry season. This study showed that the domestic sewer

Postural effects of symmetrical and asymmetrical loads on the spines of schoolchildren

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Negrini Stefano

2007-07-01

Full Text Available Abstract The school backpack constitutes a daily load for schoolchildren: we set out to analyse the postural effects of this load, considering trunk rotation, shoulder asymmetry, thoracic kyphosis, lumbar lordosis, and sagittal and frontal decompensation from the plumbline. A group of 43 subjects (mean age = 12.5 ± 0.5 years were considered: average backpack loads and average time spent getting to/from home/school (7 min had been determined in a previous study conducted on this population. Children were evaluated by means of an optoelectronic device in different conditions corresponding to their usual everyday school backpack activities: without load; bearing 12 (week maximum and 8 (week average kg symmetrical loads; bearing an 8 kg asymmetrical load; after fatigue due to backpack carrying (a 7-minute treadmill walking session bearing an 8 kg symmetrical load. Both types of load induce changes in posture: the symmetrical one in the sagittal plane, without statistical significant differences between 8 and 12 kg, and the asymmetrical one in all anatomical planes. Usual fatigue accentuates sagittal effects, but recovery of all parameters (except lumbar lordosis follows removal of the load. The backpack load effect on schoolchildren posture should be more carefully evaluated in the future, even if we must bear in mind that laws protect workers to carry heavy loads but not children, and results in the literature support the hypothesis that back pain in youngsters is correlated with back pain in adulthood

An instrumented implant for vertebral body replacement that measures loads in the anterior spinal column.

Science.gov (United States)

Rohlmann, Antonius; Gabel, Udo; Graichen, Friedmar; Bender, Alwina; Bergmann, Georg

2007-06-01

Realistic loads on a spinal implant are required among others for optimization of implant design and preclinical testing. In addition, such data may help to choose the optimal physiotherapy program for patients with such an implant and to evaluate the efficacy of aids like braces or crutches. Presently, no implant is available that can measure loads in the anterior spinal column during activities of daily life. Therefore, an implant instrumented for in vivo load measurement was developed for vertebral body replacement. The aim of this paper is to describe in detail a telemeterized implant that measures forces and moments acting on it. Six load sensors, a nine-channel telemetry unit and a coil for inductive power supply of the electronic circuits were integrated into a modified vertebral body replacement (Synex). The instrumented part of the implant is hermetically sealed. Patients are videotaped during measurements, and implant loads are displayed on and off line. The average accuracy of load measurement is better than 2% for force and 5% for moment components with reference to the maximum value of 3000 N and 20 Nm, respectively. The measuring implant described here will provide additional information on spinal loads.

Sediment transport dynamics in the Central Himalaya: assessing during monsoon the erosion processes signature in the daily suspended load of the Narayani river

Science.gov (United States)

Morin, Guillaume; Lavé, Jérôme; Lanord, Christian France; Prassad Gajurel, Ananta

2017-04-01

The evolution of mountainous landscapes is the result of competition between tectonic and erosional processes. In response to the creation of topography by tectonics, fluvial, glacial, and hillslope denudation processes erode topography, leading to rock exhumation and sediment redistribution. When trying to better document the links between climate, tectonic, or lithologic controls in mountain range evolution, a detailed understanding of the influence of each erosion process in a given environment is fundamental. At the scale of a whole mountain range, a systematic survey and monitoring of all the geomorphologic processes at work can rapidly become difficult. An alternative approach can be provided by studying the characteristics and temporal evolution of the sediments exported out of the range. In central Himalaya, the Narayani watershed presents contrasted lithologic, geochemical or isotopic signatures of the outcropping rocks as well as of the erosional processes: this particular setting allows conducting such type of approach by partly untangling the myopic vision of the spatial integration at the watershed scale. Based on the acquisition and analysis of a new dataset on the daily suspended load concentration and geochemical characteristics at the mountain outlet of one of the largest Himalayan rivers (drainage area = 30000 km2) bring several important results on Himalayan erosion, and on climatic and process controls. 1. Based on discrete depth sampling and on daily surface sampling of suspended load associated to flow characterization through ADCP measurements, we were first able to integrate sediment flux across a river cross-section and over time. We estimate for 2010 year an equivalent erosion rate of 1.8 +0.35/-0.2 mm/yr, and over the last 15 years, using past sediment load records from the DHM of Nepal, an equivalent erosion rate of 1.6 +0.3/-0.2 mm/yr. These rates are also in close agreement with the longer term ( 500 yrs) denudation rates of 1.7 mm

Individual Module Maximum Power Point Tracking for a Thermoelectric Generator Systems

DEFF Research Database (Denmark)

Vadstrup, Casper; Chen, Min; Schaltz, Erik

Thermo Electric Generator (TEG) modules are often connected in a series and/or parallel system in order to match the TEG system voltage with the load voltage. However, in order to be able to control the power production of the TEG system a DC/DC converter is inserted between the TEG system...... and the load. The DC/DC converter is under the control of a Maximum Power Point Tracker (MPPT) which insures that the TEG system produces the maximum possible power to the load. However, if the conditions, e.g. temperature, health, etc., of the TEG modules are different each TEG module will not produce its...

Indoor Noise Loading in Residential Prefabricated Buildings

Science.gov (United States)

Kraus, Michal; Juhásová Šenitková, Ingrid

2017-10-01

Quality on indoor environment is among others also defined by an acoustic comfort and noise emissions. The indoor noise loading in the residential prefabricated buildings is specific problem related to structural design of these buildings. Problems with noise level of sanitary systems are mostly associated with hydraulic shock such as water distribution and sewage drainage. Another very common cause of excessive noise is also flushing the toilet or water fall on enamelled steel (bath or shower). This paper aims to analyse the acoustic properties in the residential prefabricated buildings. Sanitary core of the assessed apartment is in original condition without any alterations. The sanitary core is based on a formica (high-pressure laminate). The study discusses the maximum sound levels in the three assessed rooms for the three different noise sources. The values of maximum noise level are measured for the corridor, bedroom and living room. Sources of noise are common activities relating to the operation of sanitary core - the toilet flush in the toilet, falling water from the shower in the bathroom and the water falling on the bottom of the kitchen sink in the kitchen. Other sources of noise are eliminated or minimized during the experiment. The digital sound level meter Testo 815 is used for measurements. The measured values of maximum sound level LA,max [dB] are adjusted by the correction coefficient. The obtained values are compared with the hygienic limits for day and night period. Night hygienic limit (30 dB) is exceeded in all the rooms for all noise sources. This limit is exceeded from 17 to 73%. The values in the bedroom and the living room meet the daily hygienic limit (40 dB). The daily limit is exceeded only in the corridor. The highest values of noise are identified for the toilet flushing.

Assessment of extreme value distributions for maximum temperature in the Mediterranean area

Science.gov (United States)

Beck, Alexander; Hertig, Elke; Jacobeit, Jucundus

2015-04-01

Extreme maximum temperatures highly affect the natural as well as the societal environment Heat stress has great effects on flora, fauna and humans and culminates in heat related morbidity and mortality. Agriculture and different industries are severely affected by extreme air temperatures. Even more under climate change conditions, it is necessary to detect potential hazards which arise from changes in the distributional parameters of extreme values, and this is especially relevant for the Mediterranean region which is characterized as a climate change hot spot. Therefore statistical approaches are developed to estimate these parameters with a focus on non-stationarities emerging in the relationship between regional climate variables and their large-scale predictors like sea level pressure, geopotential heights, atmospheric temperatures and relative humidity. Gridded maximum temperature data from the daily E-OBS dataset (Haylock et al., 2008) with a spatial resolution of 0.25° x 0.25° from January 1950 until December 2012 are the predictands for the present analyses. A s-mode principal component analysis (PCA) has been performed in order to reduce data dimension and to retain different regions of similar maximum temperature variability. The grid box with the highest PC-loading represents the corresponding principal component. A central part of the analyses is the model development for temperature extremes under the use of extreme value statistics. A combined model is derived consisting of a Generalized Pareto Distribution (GPD) model and a quantile regression (QR) model which determines the GPD location parameters. The QR model as well as the scale parameters of the GPD model are conditioned by various large-scale predictor variables. In order to account for potential non-stationarities in the predictors-temperature relationships, a special calibration and validation scheme is applied, respectively. Haylock, M. R., N. Hofstra, A. M. G. Klein Tank, E. J. Klok, P

Maximum vehicle cabin temperatures under different meteorological conditions

Science.gov (United States)

Grundstein, Andrew; Meentemeyer, Vernon; Dowd, John

2009-05-01

A variety of studies have documented the dangerously high temperatures that may occur within the passenger compartment (cabin) of cars under clear sky conditions, even at relatively low ambient air temperatures. Our study, however, is the first to examine cabin temperatures under variable weather conditions. It uses a unique maximum vehicle cabin temperature dataset in conjunction with directly comparable ambient air temperature, solar radiation, and cloud cover data collected from April through August 2007 in Athens, GA. Maximum cabin temperatures, ranging from 41-76°C, varied considerably depending on the weather conditions and the time of year. Clear days had the highest cabin temperatures, with average values of 68°C in the summer and 61°C in the spring. Cloudy days in both the spring and summer were on average approximately 10°C cooler. Our findings indicate that even on cloudy days with lower ambient air temperatures, vehicle cabin temperatures may reach deadly levels. Additionally, two predictive models of maximum daily vehicle cabin temperatures were developed using commonly available meteorological data. One model uses maximum ambient air temperature and average daily solar radiation while the other uses cloud cover percentage as a surrogate for solar radiation. From these models, two maximum vehicle cabin temperature indices were developed to assess the level of danger. The models and indices may be useful for forecasting hazardous conditions, promoting public awareness, and to estimate past cabin temperatures for use in forensic analyses.

MODEL PREDICTIVE CONTROL FOR PHOTOVOLTAIC STATION MAXIMUM POWER POINT TRACKING SYSTEM

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I. Elzein

2015-01-01

Full Text Available The purpose of this paper is to present an alternative maximum power point tracking, MPPT, algorithm for a photovoltaic module, PVM, to produce the maximum power, Pmax, using the optimal duty ratio, D, for different types of converters and load matching.We present a state-based approach to the design of the maximum power point tracker for a stand-alone photovoltaic power generation system. The system under consideration consists of a solar array with nonlinear time-varying characteristics, a step-up converter with appropriate filter.The proposed algorithm has the advantages of maximizing the efficiency of the power utilization, can be integrated to other MPPT algorithms without affecting the PVM performance, is excellent for Real-Time applications and is a robust analytical method, different from the traditional MPPT algorithms which are more based on trial and error, or comparisons between present and past states. The procedure to calculate the optimal duty ratio for a buck, boost and buck-boost converters, to transfer the maximum power from a PVM to a load, is presented in the paper. Additionally, the existence and uniqueness of optimal internal impedance, to transfer the maximum power from a photovoltaic module using load matching, is proved.

Method to support Total Maximum Daily Load development using hydrologic alteration as a surrogate to address aquatic life impairment in New Jersey streams

Science.gov (United States)

Kennen, Jonathan G.; Riskin, Melissa L.; Reilly, Pamela A.; Colarullo, Susan J.

2013-01-01

More than 300 ambient monitoring sites in New Jersey have been identified by the New Jersey Department of Environmental Protection (NJDEP) in its integrated water-quality monitoring and assessment report (that is, the 305(b) Report on general water quality and 303(d) List of waters that do not support their designated uses) as being impaired with respect to aquatic life; however, no unambiguous stressors (for example, nutrients or bacteria) have been identified. Because of the indeterminate nature of the broad range of possible impairments, surrogate measures that more holistically encapsulate the full suite of potential environmental stressors need to be developed. Streamflow alteration resulting from anthropogenic changes in the landscape is one such surrogate. For example, increases in impervious surface cover (ISC) commonly cause increases in surface runoff, which can result in “flashy” hydrology and other changes in the stream corridor that are associated with streamflow alteration. The NJDEP has indicated that methodologies to support a hydrologically based Total Maximum Daily Load (hydro-TMDL) need to be developed in order to identify hydrologic targets that represent a minimal percent deviation from a baseline condition (“minimally altered”) as a surrogate measure to meet criteria in support of designated uses. The primary objective of this study was to develop an applicable hydro-TMDL approach to address aquatic-life impairments associated with hydrologic alteration for New Jersey streams. The U.S. Geological Survey, in cooperation with the NJDEP, identified 51 non- to moderately impaired gaged streamflow sites in the Raritan River Basin for evaluation. Quantile regression (QR) analysis was used to compare flow and precipitation records and identify baseline hydrographs at 37 of these sites. At sites without an appropriately long period of record (POR) or where a baseline hydrograph could not be identified with QR, a rainfall-runoff model was used

Daily Peak Load Forecasting of Next Day using Weather Distribution and Comparison Value of Each Nearby Date Data

Science.gov (United States)

Ito, Shigenobu; Yukita, Kazuto; Goto, Yasuyuki; Ichiyanagi, Katsuhiro; Nakano, Hiroyuki

By the development of industry, in recent years; dependence to electric energy is growing year by year. Therefore, reliable electric power supply is in need. However, to stock a huge amount of electric energy is very difficult. Also, there is a necessity to keep balance between the demand and supply, which changes hour after hour. Consequently, to supply the high quality and highly dependable electric power supply, economically, and with high efficiency, there is a need to forecast the movement of the electric power demand carefully in advance. And using that forecast as the source, supply and demand management plan should be made. Thus load forecasting is said to be an important job among demand investment of electric power companies. So far, forecasting method using Fuzzy logic, Neural Net Work, Regression model has been suggested for the development of forecasting accuracy. Those forecasting accuracy is in a high level. But to invest electric power in higher accuracy more economically, a new forecasting method with higher accuracy is needed. In this paper, to develop the forecasting accuracy of the former methods, the daily peak load forecasting method using the weather distribution of highest and lowest temperatures, and comparison value of each nearby date data is suggested.

Accurate nonlinear modeling for flexible manipulators using mixed finite element formulation in order to obtain maximum allowable load

Energy Technology Data Exchange (ETDEWEB)

Esfandiar, Habib; KoraYem, Moharam Habibnejad [Islamic Azad University, Tehran (Iran, Islamic Republic of)

2015-09-15

In this study, the researchers try to examine nonlinear dynamic analysis and determine Dynamic load carrying capacity (DLCC) in flexible manipulators. Manipulator modeling is based on Timoshenko beam theory (TBT) considering the effects of shear and rotational inertia. To get rid of the risk of shear locking, a new procedure is presented based on mixed finite element formulation. In the method proposed, shear deformation is free from the risk of shear locking and independent of the number of integration points along the element axis. Dynamic modeling of manipulators will be done by taking into account small and large deformation models and using extended Hamilton method. System motion equations are obtained by using nonlinear relationship between displacements-strain and 2nd PiolaKirchoff stress tensor. In addition, a comprehensive formulation will be developed to calculate DLCC of the flexible manipulators during the path determined considering the constraints end effector accuracy, maximum torque in motors and maximum stress in manipulators. Simulation studies are conducted to evaluate the efficiency of the method proposed taking two-link flexible and fixed base manipulators for linear and circular paths into consideration. Experimental results are also provided to validate the theoretical model. The findings represent the efficiency and appropriate performance of the method proposed.

Accurate nonlinear modeling for flexible manipulators using mixed finite element formulation in order to obtain maximum allowable load

International Nuclear Information System (INIS)

Esfandiar, Habib; KoraYem, Moharam Habibnejad

2015-01-01

In this study, the researchers try to examine nonlinear dynamic analysis and determine Dynamic load carrying capacity (DLCC) in flexible manipulators. Manipulator modeling is based on Timoshenko beam theory (TBT) considering the effects of shear and rotational inertia. To get rid of the risk of shear locking, a new procedure is presented based on mixed finite element formulation. In the method proposed, shear deformation is free from the risk of shear locking and independent of the number of integration points along the element axis. Dynamic modeling of manipulators will be done by taking into account small and large deformation models and using extended Hamilton method. System motion equations are obtained by using nonlinear relationship between displacements-strain and 2nd PiolaKirchoff stress tensor. In addition, a comprehensive formulation will be developed to calculate DLCC of the flexible manipulators during the path determined considering the constraints end effector accuracy, maximum torque in motors and maximum stress in manipulators. Simulation studies are conducted to evaluate the efficiency of the method proposed taking two-link flexible and fixed base manipulators for linear and circular paths into consideration. Experimental results are also provided to validate the theoretical model. The findings represent the efficiency and appropriate performance of the method proposed.

Improved Maximum Strength, Vertical Jump and Sprint Performance after 8 Weeks of Jump Squat Training with Individualized Loads

Directory of Open Access Journals (Sweden)

Vanderka Marián, Longová Katarína, Olasz Dávid, Krčmár Matúš, Walker Simon

2016-09-01

Full Text Available The purpose of the study was to determine the effects of 8 weeks of jump squat training on isometric half squat maximal force production (Fmax and rate of force development over 100ms (RFD100, countermovement jump (CMJ and squat jump (SJ height, and 50 m sprint time in moderately trained men. Sixty eight subjects (~21 years, ~180 cm, ~75 kg were divided into experimental (EXP; n = 36 and control (CON, n = 32 groups. Tests were completed pre-, mid- and post-training. EXP performed jump squat training 3 times per week using loads that allowed all repetitions to be performed with ≥90% of maximum average power output (13 sessions with 4 sets of 8 repetitions and 13 sessions with 8 sets of 4 repetitions. Subjects were given real-time feedback for every repetition during the training sessions. Significant improvements in Fmax from pre- to mid- (Δ ~14%, p<0.001, and from mid- to post-training (Δ ~4%, p < 0.001 in EXP were observed. In CON significantly enhanced Fmax from pre- to mid-training (Δ ~3.5%, p < 0.05 was recorded, but no other significant changes were observed in any other test. In RFD100 significant improvements from pre- to mid-training (Δ ~27%, p < 0.001, as well as from mid- to post-training (Δ ~17%, p < 0.01 were observed. CMJ and SJ height were significantly enhanced from pre- to mid-training (Δ ~10%, ~15%, respectively, p < 0.001 but no further changes occurred from mid- to post-training. Significant improvements in 50 m sprint time from pre- to mid-training (Δ -1%, p < 0.05, and from mid- to post-training (Δ -1.9%, p < 0.001 in EXP were observed. Furthermore, percent changes in EXP were greater than changes in CON during training. It appears that using jump squats with loads that allow repetitions to be performed ≥90% of maximum average power output can simultaneously improve several different athletic performance tasks in the short-term.

ANALYSIS OF HYDRAULIC LOAD OF SELECTED WASTEWATER TREATMENT PLANT IN JASŁO COUNTY

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Dariusz Piotr Młyński

2016-12-01

Full Text Available The paper presents an analysis of hydraulic load in selected a wastewater treatment plant (WTP in Jasło County: in Przysieki, Kołaczyce and Szebnie. The study was based on the records of daily sewage volume entering the treatment plants within a multi-year period of 2011-2014. The analysis took into account the average daily amount of incoming sewage, the maximum daily peaking factor for the incoming sewage, changes in the sewage volume depending on specific month and the intervals with the greatest frequency of occurrence were designated. The analysis revealed that investigated wastewater treatment plants were hydraulically underloaded. Moreover it was conclude a significant variables of inflowing sewage amount. The sewage admission was the largest in spring and summer periods. Sewage volume interval most often occurring at the WTP in Przysieki was the one between 320 and 480 m3•d-1, for Kołaczyce between 290 and 320 m3•d-1 and Szebnie between 120 and 240 m3•d-1.

Daily storage management of hydroelectric facilities

NARCIS (Netherlands)

Chappin, E.J.L.; Ferrero, M.; Lazzeroni, P.; Lukszo, Z.; Olivero, M.; Repetto, M.

2012-01-01

This work presents a management procedure for hydroelectric facilities with daily storage. The water storage gives an additional degree of freedom allowing to shift in time power production when it is more convenient and to work at the maximum efficiency of hydraulic turbine. The management is

Load calculations of radiant cooling systems for sizing the plant

DEFF Research Database (Denmark)

Bourdakis, Eleftherios; Kazanci, Ongun Berk; Olesen, Bjarne W.

2015-01-01

The aim of this study was, by using a building simulation software, to prove that a radiant cooling system should not be sized based on the maximum cooling load but at a lower value. For that reason six radiant cooling models were simulated with two control principles using 100%, 70% and 50......% of the maximum cooling load. It was concluded that all tested systems were able to provide an acceptable thermal environment even when the 50% of the maximum cooling load was used. From all the simulated systems the one that performed the best under both control principles was the ESCS ceiling system. Finally...... it was proved that ventilation systems should be sized based on the maximum cooling load....

Load bearing and deformation behaviour of dynamically loaded wide plate specimens

International Nuclear Information System (INIS)

Julisch, P.; Haedrich, H.J.; Stadtmueller, W.; Sturm, D.

1989-01-01

For the testing of large-scale specimens, a 12 MN-High Loading Rate Tensile Testing Machine was designed and built at MPA Stuttgart. The aim was to determine the influence of high loading rates on the stress and strain behaviour of unwelded and welded components of ferritic and austenitic materials. This new generation of testing machines is driven by a propellant charge, and generates a maximum tensile force of 12 MN with a piston velocity of 25 m/s after a stroke of 20 mm, or a maximum velocity of 60 m/s after a stroke of 400 mm. In a first test programme, welded and unwelded wide plate specimens made of material X 6 CrNi 18 11 were tested at room temperature with different strain rates from 10 -3 /s to 63/s. In addition to a description of the 12 MN-High Loading Rate Tensile Testing Machine, the results of the high loading rate tensile tests performed will be presented and compared with quasistatically tested wide plate specimens. (orig.)

Influence of crop load on almond tree water status and its importance in irrigation scheduling

Science.gov (United States)

Puerto Conesa, Pablo; Domingo Miguel, Rafael; Torres Sánchez, Roque; Pérez Pastor, Alejandro

2014-05-01

In the Mediterranean area water is the main factor limiting crop production and therefore irrigation is essential to achieve economically viable yields. One of the fundamental techniques to ensure that irrigation water is managed efficiently with maximum productivity and minimum environmental impact is irrigation scheduling. The fact that the plant water status integrates atmospheric demand and soil water content conditions encourages the use of plant-based water status indicators. Some researchers have successfully scheduled irrigation in certain fruit trees by maintaining the maximum daily trunk diameter shrinkage (MDS) signal intensity at threshold values to generate (or not) water stress. However MDS not only depends on the climate and soil water content, but may be affected by tree factors such as age, size, phenological stage and fruit load. There is therefore a need to quantify the influence of these factors on MDS. The main objective of this work was to study the effects of crop load on tree water relations for scheduling purposes. We particularly focused on MDS vs VPD10-15 (mean air vapor pressure deficit during the period 10.00-15.00 h solar time) for different loads and phenological phases under non-limiting soil water conditions. The experiment was carried out in 2011 in a 1 ha plot in SE Spain with almond trees (Prunus dulcis (Mill.) D.A. Webb cv. 'Marta'). Three crop load treatments were studied according to three crop load levels, i) T100, high crop load, characteristic crop load, ii) T50, medium crop load, in which 50% of the fruits were removed and iii) T0, practically without fruits. Fruits were manually thinned. Each treatment, randomly distributed in blocks, was run in triplicate. Plant water status was assessed from midday stem water potential (Ψs), MDS, daily trunk growth rate (TGR), leaf turgor potential Ψp, fruit water potential (Ψf), stomatal conductance (gs) and photosynthesis (Pn) and transpiration rates (E). Yield, pruning weights and

Estimating daily minimum, maximum, and mean near surface air temperature using hybrid satellite models across Israel.

Science.gov (United States)

Rosenfeld, Adar; Dorman, Michael; Schwartz, Joel; Novack, Victor; Just, Allan C; Kloog, Itai

2017-11-01

Meteorological stations measure air temperature (Ta) accurately with high temporal resolution, but usually suffer from limited spatial resolution due to their sparse distribution across rural, undeveloped or less populated areas. Remote sensing satellite-based measurements provide daily surface temperature (Ts) data in high spatial and temporal resolution and can improve the estimation of daily Ta. In this study we developed spatiotemporally resolved models which allow us to predict three daily parameters: Ta Max (day time), 24h mean, and Ta Min (night time) on a fine 1km grid across the state of Israel. We used and compared both the Aqua and Terra MODIS satellites. We used linear mixed effect models, IDW (inverse distance weighted) interpolations and thin plate splines (using a smooth nonparametric function of longitude and latitude) to first calibrate between Ts and Ta in those locations where we have available data for both and used that calibration to fill in neighboring cells without surface monitors or missing Ts. Out-of-sample ten-fold cross validation (CV) was used to quantify the accuracy of our predictions. Our model performance was excellent for both days with and without available Ts observations for both Aqua and Terra (CV Aqua R 2 results for min 0.966, mean 0.986, and max 0.967; CV Terra R 2 results for min 0.965, mean 0.987, and max 0.968). Our research shows that daily min, mean and max Ta can be reliably predicted using daily MODIS Ts data even across Israel, with high accuracy even for days without Ta or Ts data. These predictions can be used as three separate Ta exposures in epidemiology studies for better diurnal exposure assessment. Copyright © 2017 Elsevier Inc. All rights reserved.

Carga máxima de fósforo admissível ao reservatório Piraquara II, uma aplicação do processo TMDL Maximum allowable phosphorus load in the Piraquara II reservoir, a TMDL process application

Directory of Open Access Journals (Sweden)

Simone Bittencourt

2006-06-01

Full Text Available Para implementação e operacionalização da política brasileira de recursos hídricos, é imprescindível o uso de ferramentas de planejamento que considerem o efeito de todas as atividades ou processos que causam ou contribuem para a degradação da qualidade de um corpo d'água. Neste sentido, aplicou-se o processo TMDL (total maximum daily load, desenvolvido pela Agência de Proteção Ambiental dos Estados Unidos (EPA, para o P, na área de drenagem de contribuição ao futuro reservatório Piraquara II, bacia hidrográfica do rio Piraquara, Paraná. O processo TMDL determina a quantidade máxima de cargas de um poluente que um corpo d'água pode receber sem violar os padrões estabelecidos de qualidade da água e aloca cargas deste poluente entre fontes de poluição pontuais e difusas. No presente estudo, utilizou-se o método TMDL, com o objetivo de demonstrar ser ele uma ferramenta útil no processo de gestão dos recursos hídricos. Simularam-se cenários de uso do solo, por meio de modelagem matemática, até obter-se uma concentração de P total no reservatório abaixo da faixa limite para ocorrência de eutrofização, de 0,025 a 0,10 mg L-1, estabelecida no estudo. Realizou-se uma simulação de uso atual do solo, visando prever a condição inicial de qualidade da água no corpo d'água, na qual a concentração de P total no reservatório resultante não atendeu ao padrão estabelecido. Procedeu-se a uma segunda simulação com adoção das medidas de controle, recomposição de mata ciliar e plantio direto, para reduzir a exportação de carga de P total da bacia. Obteve-se uma melhoria na qualidade da água do reservatório, indicando que as medidas adotadas foram suficientes para atingir o padrão estabelecido, o que demonstra a aplicabilidade do método.For the implementation and operation of the Brazilian Federal law on water resources of 1997 it is indispensable to use planning tools that take into account the effect of

Maximum Power Point Tracking Using Sliding Mode Control for Photovoltaic Array

Directory of Open Access Journals (Sweden)

J. Ghazanfari

2013-09-01

Full Text Available In this paper, a robust Maximum Power Point Tracking (MPPT for PV array has been proposed using sliding mode control by defining a new formulation for sliding surface which is based on increment conductance (INC method. The stability and robustness of the proposed controller are investigated to load variations and environment changes. Three different types of DC-DC converter are used in Maximum Power Point (MPP system and the results obtained are given. The simulation results confirm the effectiveness of the proposed method in the presence of load variations and environment changes for different types of DC-DC converter topologies.

Evaluation of reactivity and Xe behavior during daily load following operation

International Nuclear Information System (INIS)

Sakamoto, Yasunori; Araki, Tsuneyasu; Yamamoto, Fumiaki

1992-01-01

A boiling water reactor (BWR) has an excellent load following capability provided by a core flow control, which is used for changing a reactor power level and for compensating the subsequent Xe concentration change. The core characteristics during load following operations are investigated in detail, using our reactor core simulator. Comparisons of changes of the Doppler reactivity, the void reactivity and the Xe reactivity during transients are performed. Also the features of Xe transient during load following operations are shown. It has been shown that the core flow change required to compensate the Xe reactivity change produces much greater change of the void reactivity than that required for power level changes, and that the resulting local power change in the lower part of the core is greater than that in the upper part, because the Xe concentration change in the lower part is hardly compensated by the core flow control. Also the effects of power level changes, cycle patterns, and initial concentration of Xe and I on the Xe transient behavior have been investigated. (author)

Alaska Village Electric Load Calculator

Energy Technology Data Exchange (ETDEWEB)

Devine, M.; Baring-Gould, E. I.

2004-10-01

As part of designing a village electric power system, the present and future electric loads must be defined, including both seasonal and daily usage patterns. However, in many cases, detailed electric load information is not readily available. NREL developed the Alaska Village Electric Load Calculator to help estimate the electricity requirements in a village given basic information about the types of facilities located within the community. The purpose of this report is to explain how the load calculator was developed and to provide instructions on its use so that organizations can then use this model to calculate expected electrical energy usage.

Accident loads for a VVER-440/213 containment

Energy Technology Data Exchange (ETDEWEB)

Techy, Z. [Institute for Electric Power Research (VEIKI), Budapest (Hungary); Lajtha, G. [Institute for Electric Power Research (VEIKI), Budapest (Hungary); Taubner, R. [Institute for Electric Power Research (VEIKI), Budapest (Hungary)

1995-08-01

Specific features of the VVER-440/213 containment are the subdivided rectangular building and the localization system including the bubbler trays and air traps. Accident loads are calculated for a large break loss of coolant accident (LBLOCA). The maximum pressure and temperature loads are calculated with different codes during the blowdown phase of the LBLOCA. The uncertainty margins of the maximum pressure are given in this case. Sensitivity studies are performed for different leakage rates and hydraulic data of the containment. The effects of the active and passive spray systems on the depressurization are presented in this paper. The maximum pressure loads are also examined in case of degraded conditions of the localization system. (orig.).

Maximum gain of Yagi-Uda arrays

DEFF Research Database (Denmark)

Bojsen, J.H.; Schjær-Jacobsen, Hans; Nilsson, E.

1971-01-01

Numerical optimisation techniques have been used to find the maximum gain of some specific parasitic arrays. The gain of an array of infinitely thin, equispaced dipoles loaded with arbitrary reactances has been optimised. The results show that standard travelling-wave design methods are not optimum....... Yagi–Uda arrays with equal and unequal spacing have also been optimised with experimental verification....

Selective effects of weight and inertia on maximum lifting.

Science.gov (United States)

Leontijevic, B; Pazin, N; Kukolj, M; Ugarkovic, D; Jaric, S

2013-03-01

A novel loading method (loading ranged from 20% to 80% of 1RM) was applied to explore the selective effects of externally added simulated weight (exerted by stretched rubber bands pulling downward), weight+inertia (external weights added), and inertia (covariation of the weights and the rubber bands pulling upward) on maximum bench press throws. 14 skilled participants revealed a load associated decrease in peak velocity that was the least associated with an increase in weight (42%) and the most associated with weight+inertia (66%). However, the peak lifting force increased markedly with an increase in both weight (151%) and weight+inertia (160%), but not with inertia (13%). As a consequence, the peak power output increased most with weight (59%), weight+inertia revealed a maximum at intermediate loads (23%), while inertia was associated with a gradual decrease in the peak power output (42%). The obtained findings could be of importance for our understanding of mechanical properties of human muscular system when acting against different types of external resistance. Regarding the possible application in standard athletic training and rehabilitation procedures, the results speak in favor of applying extended elastic bands which provide higher movement velocity and muscle power output than the usually applied weights. © Georg Thieme Verlag KG Stuttgart · New York.

Intramural Injection with Botulinum Toxin Type A in Piglet Esophagus. The Influencer on Maximum Load and Elongation: A Dose Response Study.

Science.gov (United States)

Ellebæk, Mark Bremholm; Qvist, Niels; Schrøder, Henrik Daa; Rasmussen, Lars

2016-06-01

Introduction The treatment of esophageal atresia (OA) is challenging. The main goal is to achieve primary anastomosis. We have previously demonstrated in a pig model that intramural injection of botulinum toxin type A (BTX-A) resulted in significant elongation of the esophagus during tensioning until bursting point. The objectives of the present study were to investigate the influence of different amounts of intramural BTX-A on the stretch-tension characteristics and histological changes of the esophagus in piglets. Materials and Methods A total of 52 piglets were randomized to four groups receiving 2, 4, or 8 units/kg of BTX-A or isotonic saline (placebo). After a 1-hour of rest the esophagus was harvested and subjected to a stretch-tension test and histological examination to assess changes in the density of presynaptic vesicles in the nerve cells. Results Overall, 9 of the 52 animals were excluded from analysis due to problems with the stretch-tension test or death from anesthesia. The maximum loads were higher in the BTX-A groups (2 units/kg: +2.1 N; 4 units/kg: +1.3 N; 8 units/kg: +1.9 N) than the placebo (p = 0.046). There were no significant differences in percentage elongation, or histology. Conclusions This study demonstrated that injection of 2 units/kg BTX-A into a nonanastomosed esophageal wall resulted in a modest increase in the maximum load achieved before bursting; this may be due to the muscle-relaxant effect of BTX-A. BTX-A injection produced no significant effects on elongation or esophageal histology. The clinical usefulness of BTX-A in treatment of OA is still unclear. Georg Thieme Verlag KG Stuttgart · New York.

Impact of Paint Color on Rest Period Climate Control Loads in Long-Haul Trucks: Preprint

Energy Technology Data Exchange (ETDEWEB)

Lustbader, J.; Kreutzer, C.; Jeffers, M.; Adelman, S.; Yeakel, S.; Brontz, P.; Olson, K.; Ohlinger, J.

2014-02-01

Cab climate conditioning is one of the primary reasons for operating the main engine in a long-haul truck during driver rest periods. In the United States, sleeper cab trucks use approximately 667 million gallons of fuel annually for rest period idling. The U.S. Department of Energy's National Renewable Energy Laboratory's (NREL) CoolCab Project works closely with industry to design efficient thermal management systems for long-haul trucks that minimize engine idling and fuel use while maintaining occupant comfort. Heat transfer to the vehicle interior from opaque exterior surfaces is one of the major heat pathways that contribute to air conditioning loads during long-haul truck daytime rest period idling. To quantify the impact of paint color and the opportunity for advanced paints, NREL collaborated with Volvo Group North America, PPG Industries, and Dometic Environmental Corporation. Initial screening simulations using CoolCalc, NREL's rapid HVAC load estimation tool, showed promising air-conditioning load reductions due to paint color selection. Tests conducted at NREL's Vehicle Testing and Integration Facility using long-haul truck cab sections, 'test bucks,' showed a 31.1% of maximum possible reduction in rise over ambient temperature and a 20.8% reduction in daily electric air conditioning energy use by switching from black to white paint. Additionally, changing from blue to an advanced color-matched solar reflective blue paint resulted in a 7.3% reduction in daily electric air conditioning energy use for weather conditions tested in Colorado. National-level modeling results using weather data from major U.S. cities indicated that the increase in heating loads due to lighter paint colors is much smaller than the reduction in cooling loads.

Sustained-release diclofenac potassium-loaded solid lipid microparticle based on solidified reverse micellar solution: in vitro and in vivo evaluation.

Science.gov (United States)

Chime, Salome Amarachi; Attama, Anthony Amaechi; Builders, Philip F; Onunkwo, Godswill C

2013-01-01

To formulate sustained-release diclofenac potassium-loaded solid lipid microparticles (SLMs) based on solidified reverse micellar solution (SRMS) and to evaluate the in vitro and in vivo properties. SRMS consisting of mixtures of Phospholipon® 90H and Softisan® 154 were used to formulate diclofenac potassium-loaded SLMs. Characterization based on the particle size and morphology, stability and encapsulation efficiency (EE%) were carried out on the SLMs. In vitro release was carried out in simulated intestinal fluid (pH 7.5). Anti-inflammatory and ulcerogenic properties were studied using rats. Maximum EE% of 95%, 94% and 93% were obtained for SLMs formulated with SRMS 1:1, 2:1 and 1:2, respectively. In vitro release showed about 85-90% drug release at 13 h. Diclofenac potassium-loaded SLMs showed good anti-inflammatory and gastro-protective properties. Diclofenac potassium-loaded SLMs based on SRMS could be used orally or parenterally under controlled conditions, for once daily administration.

Load flow analysis using decoupled fuzzy load flow under critical ...

African Journals Online (AJOL)

user

3.1 Maximum range selection of input and output variables: ..... Wong K. P., Li A., and Law M.Y., “ Advanced Constrained Genetic Algorithm Load Flow Method”, IEE Proc. ... Dr. Parimal Acharjee passed B.E.E. from North Bengal University ...

Determination of strength exercise intensities based on the load-power-velocity relationship.

Science.gov (United States)

Jandačka, Daniel; Beremlijski, Petr

2011-06-01

The velocity of movement and applied load affect the production of mechanical power output and subsequently the extent of the adaptation stimulus in strength exercises. We do not know of any known function describing the relationship of power and velocity and load in the bench press exercise. The objective of the study is to find a function modeling of the relationship of relative velocity, relative load and mechanical power output for the bench press exercise and to determine the intensity zones of the exercise for specifically focused strength training of soccer players. Fifteen highly trained soccer players at the start of a competition period were studied. The subjects of study performed bench presses with the load of 0, 10, 30, 50, 70 and 90% of the predetermined one repetition maximum with maximum possible speed of movement. The mean measured power and velocity for each load (kg) were used to develop a multiple linear regression function which describes the quadratic relationship between the ratio of power (W) to maximum power (W) and the ratios of the load (kg) to one repetition maximum (kg) and the velocity (m•s(-1)) to maximal velocity (m•s(-1)). The quadratic function of two variables that modeled the searched relationship explained 74% of measured values in the acceleration phase and 75% of measured values from the entire extent of the positive power movement in the lift. The optimal load for reaching maximum power output suitable for the dynamics effort strength training was 40% of one repetition maximum, while the optimal mean velocity would be 75% of maximal velocity. Moreover, four zones: maximum power, maximum velocity, velocity-power and strength-power were determined on the basis of the regression function.

Solar maximum mission panel jettison analysis remote manipulator system

Science.gov (United States)

Bauer, R. B.

1980-01-01

A study is presented of the development of the Remote Manipulator System (RMS) configurations for jettison of the solar panels on the Solar Maximum Mission/Multimission Satellite. A valid RMS maneuver between jettison configurations was developed. Arm and longeron loads and effector excursions due to the solar panel jettison were determined to see if they were within acceptable limits. These loads and end effector excursions were analyzed under two RMS modes, servos active in position hold submode, and in the brakes on mode.

Daily physical activity and its relation to aerobic fitness in children aged 8-11 years

DEFF Research Database (Denmark)

Dencker, Magnus; Thorsson, Ola; Karlsson, Magnus K.

2006-01-01

and fitness in children has been published, where fitness has been assessed by direct measurement of maximum oxygen uptake and related to daily physical activity intensities by accelerometers. We examined 248 children (140 boys and 108 girls), aged 7.9-11.1 years. Maximum workload and maximal oxygen uptake...... in vigorous physical activity were calculated. VO2PEAK was correlated with mean accelerometer counts (r=0.23 for boys and r=0.23 for girls, both Pactivity (r=0.32 for boys, r=0.30 for girls, both P...Abstract  A positive relationship between daily physical activity and aerobic fitness exists in adults. Studies in children have given conflicting results, possibly because of differences in methods used to assess daily physical activity and fitness. No study regarding daily physical activity...

Verification of average daily maximum permissible concentration of styrene in the atmospheric air of settlements under the results of epidemiological studies of the children’s population

Directory of Open Access Journals (Sweden)

М.А. Zemlyanova

2015-03-01

Full Text Available We presented the materials on the verification of the average daily maximum permissible concentration of styrene in the atmospheric air of settlements performed under the results of own in-depth epidemiological studies of children’s population according to the principles of the international risk assessment practice. It was established that children in the age of 4–7 years when exposed to styrene at the level above 1.2 of threshold level value for continuous exposure develop the negative exposure effects in the form of disorders of hormonal regulation, pigmentary exchange, antioxidative activity, cytolysis, immune reactivity and cytogenetic disbalance which contribute to the increased morbidity of diseases of the central nervous system, endocrine system, respiratory organs, digestion and skin. Based on the proved cause-and-effect relationships between the biomarkers of negative effects and styrene concentration in blood it was demonstrated that the benchmark styrene concentration in blood is 0.002 mg/dm3. The justified value complies with and confirms the average daily styrene concentration in the air of settlements at the level of 0.002 mg/m3 accepted in Russia which provides the safety for the health of population (1 threshold level value for continuous exposure.

Influence of the Metal Volume Fraction on the maximum deflection and impact load of GLARE plates subjected to low velocity impact

Science.gov (United States)

Bikakis, GSE; Savaidis, A.; Zalimidis, P.; Tsitos, S.

2016-11-01

Fiber-metal laminates are hybrid composite materials, consisting of alternating metal layers bonded to fiber-reinforced prepreg layers. GLARE (GLAss REinforced) belongs to this new family of materials. GLARE is the most successful fiber-metal laminate up to now and is currently being used for the construction of primary aerospace structures, such as the fuselage of the Airbus A380 air plane. Impact properties are very important in aerospace structures, since impact damage is caused by various sources, such as maintenance damage from dropped tools, collision between service cars or cargo and the structure, bird strikes and hail. The principal objective of this article is to evaluate the influence of the Metal Volume Fraction (MVF) on the low velocity impact response of GLARE fiber-metal laminates. Previously published differential equations of motion are employed for this purpose. The low velocity impact behavior of various circular GLARE plates is predicted and characteristic values of impact variables, which represent the impact phenomenon, are evaluated versus the corresponding MVF of the examined GLARE material grades. The considered GLARE plates are subjected to low velocity impact under identical impact conditions. A strong effect of the MVF on the maximum impact load and a significant effect on the maximum plate deflection of GLARE plates has been found.

Residual torsional properties of composite shafts subjected to impact loadings

International Nuclear Information System (INIS)

Sevkat, Ercan; Tumer, Hikmet

2013-01-01

Highlights: • Impact loading reduces the torsional strength of composite shaft. • Impact energy level determines the severity of torsional strength reduction. • Hybrid composite shafts can be manufactured by mixing two types of filament. • Maximum torque capacity of shafts can be estimated using finite element method. - Abstract: This paper presents an experimental and numerical study to investigate residual torsional properties of composite shafts subjected to impact loadings. E-glass/epoxy, carbon/epoxy and E-glass–carbon/epoxy hybrid composite shafts were manufactured by filament winding method. Composite shafts were impacted at 5, 10, 20 and 40 J energy levels. Force–time and energy–time histories of impact tests were recorded. One composite shaft with no impact, and four composite shafts with impact damage, five in total, were tested under torsion. Torque-twisting angle relations for each test were obtained. Reduction at maximum torque and maximum twisting angle induced by impact loadings were calculated. While 5 J impact did not cause significant reduction at maximum torque and maximum twisting angle, remaining impact loadings caused 34–67% reduction at maximum torque, and 30–61% reduction at maximum twisting angle. Reductions increased with increasing energy levels and varied depending on the material of composite shafts. The 3-D finite element (FE) software, Abaqus, incorporated with an elastic orthotropic model, was then used to simulate the torsion tests. Good agreement between experimental and numerical results was achieved

Economic impact analysis of load forecasting

International Nuclear Information System (INIS)

Ranaweera, D.K.; Karady, G.G.; Farmer, R.G.

1997-01-01

Short term load forecasting is an essential function in electric power system operations and planning. Forecasts are needed for a variety of utility activities such as generation scheduling, scheduling of fuel purchases, maintenance scheduling and security analysis. Depending on power system characteristics, significant forecasting errors can lead to either excessively conservative scheduling or very marginal scheduling. Either can induce heavy economic penalties. This paper examines the economic impact of inaccurate load forecasts. Monte Carlo simulations were used to study the effect of different load forecasting accuracy. Investigations into the effect of improving the daily peak load forecasts, effect of different seasons of the year and effect of utilization factors are presented

New England observed and predicted August stream/river temperature maximum daily rate of change points

Data.gov (United States)

U.S. Environmental Protection Agency — The shapefile contains points with associated observed and predicted August stream/river temperature maximum negative rate of change in New England based on a...

A simple method to downscale daily wind statistics to hourly wind data

OpenAIRE

Guo, Zhongling

2013-01-01

Wind is the principal driver in the wind erosion models. The hourly wind speed data were generally required for precisely wind erosion modeling. In this study, a simple method to generate hourly wind speed data from daily wind statistics (daily average and maximum wind speeds together or daily average wind speed only) was established. A typical windy location with 3285 days (9 years) measured hourly wind speed data were used to validate the downscaling method. The results showed that the over...

Fractal Dimension and Maximum Sunspot Number in Solar Cycle

Directory of Open Access Journals (Sweden)

R.-S. Kim

2006-09-01

Full Text Available The fractal dimension is a quantitative parameter describing the characteristics of irregular time series. In this study, we use this parameter to analyze the irregular aspects of solar activity and to predict the maximum sunspot number in the following solar cycle by examining time series of the sunspot number. For this, we considered the daily sunspot number since 1850 from SIDC (Solar Influences Data analysis Center and then estimated cycle variation of the fractal dimension by using Higuchi's method. We examined the relationship between this fractal dimension and the maximum monthly sunspot number in each solar cycle. As a result, we found that there is a strong inverse relationship between the fractal dimension and the maximum monthly sunspot number. By using this relation we predicted the maximum sunspot number in the solar cycle from the fractal dimension of the sunspot numbers during the solar activity increasing phase. The successful prediction is proven by a good correlation (r=0.89 between the observed and predicted maximum sunspot numbers in the solar cycles.

Daily extreme temperature multifractals in Catalonia (NE Spain)

International Nuclear Information System (INIS)

Burgueño, A.; Lana, X.; Serra, C.; Martínez, M.D.

2014-01-01

The multifractal character of the daily extreme temperatures in Catalonia (NE Spain) is analyzed by means of the multifractal detrended fluctuation analysis (MF-DFA) applied to 65 thermometric records covering years 1950–2004. Although no clear spatial patterns of the multifractal spectrum parameters appear, factor scores deduced from Principal Component analysis indicate some signs of spatial gradients. Additionally, the daily extreme temperature series are classified depending on their complex time behavior, through four multifractal parameters (Hurst exponent, Hölder exponent with maximum spectrum, spectrum asymmetry and spectrum width). As a synthesis of the three last parameters, a basic measure of complexity is proposed through a normalized Complexity Index. Its regional behavior is found to be free of geographical dependences. This index represents a new step towards the description of the daily extreme temperatures complexity.

Daily extreme temperature multifractals in Catalonia (NE Spain)

Energy Technology Data Exchange (ETDEWEB)

Burgueño, A. [Departament d' Astronomia i Meteorologia, Universitat de Barcelona, Barcelona (Spain); Lana, X., E-mail: francisco.javier.lana@upc.edu [Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Barcelona (Spain); Serra, C. [Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Barcelona (Spain); Martínez, M.D. [Departament de Física Aplicada, Universitat Politècnica de Catalunya, Barcelona (Spain)

2014-02-01

The multifractal character of the daily extreme temperatures in Catalonia (NE Spain) is analyzed by means of the multifractal detrended fluctuation analysis (MF-DFA) applied to 65 thermometric records covering years 1950–2004. Although no clear spatial patterns of the multifractal spectrum parameters appear, factor scores deduced from Principal Component analysis indicate some signs of spatial gradients. Additionally, the daily extreme temperature series are classified depending on their complex time behavior, through four multifractal parameters (Hurst exponent, Hölder exponent with maximum spectrum, spectrum asymmetry and spectrum width). As a synthesis of the three last parameters, a basic measure of complexity is proposed through a normalized Complexity Index. Its regional behavior is found to be free of geographical dependences. This index represents a new step towards the description of the daily extreme temperatures complexity.

Full-scale load tests of Pearl-Chain arches

DEFF Research Database (Denmark)

Halding, Philip Skov; Hertz, Kristian Dahl; Schmidt, Jacob Wittrup

2017-01-01

-Decks: First an investigation of the system’s elastic response (maximum load of 648kN), and second a demonstration of its collapse mechanism and ultimate capacity (maximum load of 970kN). The full-scale test showed formation of plastic hinges and clear warning signs are observed at 84% of the failure load......A full-scale load test is made of two Pearl-Chain (PC) concrete arches in order to evaluate the structural response and assess the design safety. Pearl-Chain structures and Pearl-Chain arches are invented and patented at the Technical University of Denmark. PC-Arches consist of specially designed....... The ultimate, experimental load capacity is 14% higher than the calculated mainly due to the assumed static system used for the calculation. In addition to the full-scale test bridge the first ever permanent PC-Bridge is erected in Denmark in 2015....

Optimization between heating load and entropy-production rate for endoreversible absorption heat-transformers

International Nuclear Information System (INIS)

Sun Fengrui; Qin Xiaoyong; Chen Lingen; Wu Chih

2005-01-01

For an endoreversible four-heat-reservoir absorption heat-transformer cycle, for which a linear (Newtonian) heat-transfer law applies, an ecological optimization criterion is proposed for the best mode of operation of the cycle. This involves maximizing a function representing the compromise between the heating load and the entropy-production rate. The optimal relation between the ecological criterion and the COP (coefficient of performance), the maximum ecological criterion and the corresponding COP, heating load and entropy production rate, as well as the ecological criterion and entropy-production rate at the maximum heating load are derived using finite-time thermodynamics. Moreover, compared with the heating-load criterion, the effects of the cycle parameters on the ecological performance are studied by numerical examples. These show that achieving the maximum ecological criterion makes the entropy-production rate decrease by 77.0% and the COP increase by 55.4% with only 27.3% heating-load losses compared with the maximum heating-load objective. The results reflect that the ecological criterion has long-term significance for optimal design of absorption heat-transformers

A rational evaluation of structural design loads

International Nuclear Information System (INIS)

Tasaka, S.

1993-01-01

The reliability-based seismic design of structures is a design method ensuring that the structural seismic capacity is not less than the maximum seismic load or load effect for a prescribed value of the reliability index, wherein the design reference period, n, is used to specify the n-year maximum load. In the conventional Load and Resistance Factor Design (LRFD) method the design load is commonly determined on the basis of the n-year maximum the probability distribution of which may be given in some different ways. However, in contrast with the structural capacity the n-year maximum load usually involves much larger variabilities. The effort to decrease the variability would, hence, be effective for the purpose of avoiding nuclear power plant (NPP) structures having unnecessarily large capacities. A possible way to do this is to consider the joint probability distribution of the n-year 1st and 2nd maxima of the seismic load derived from the formula of extreme order statistics. Since the reliability index is conventionally associated with the n-year 1st maximum, the conditional probability distribution rather than the joint one of the n-year 1st maximum given a value of the n-year 2nd one will be considered. Three conditional extreme value distributions, which correspond to the usual extreme value distributions of Types I, II and III, and their statistical moments up to the second order are presented. Within the framework of the first-order second moment method, the conditional statistical moments are utilized to calculate the reliability index as well as the design value of the seismic load. The seismic load considered herein is represented by the peak ground acceleration (PGA) in n years. The present scheme is applied to evaluate the design PGA's at II sites in Japan where samples of the annual 1st and 2nd PGA's have been obtained by using historical seismic data. In this application the following two points are of our interest: (a) Define the reliability

49 CFR 237.71 - Determination of bridge load capacities.

Science.gov (United States)

2010-10-01

... capacity shall be determined. (g) Bridge load capacity may be expressed in terms of numerical values related to a standard system of bridge loads, but shall in any case be stated in terms of weight and...) Bridge load capacity may be expressed in terms of both normal and maximum load conditions. Operation of...

Cluster analysis of residential heat load profiles and the role of technical and household characteristics

DEFF Research Database (Denmark)

Carmo, Carolina; Christensen, Toke Haunstrup

2016-01-01

of the temporality of the energy demand is needed. This paper contributes to this by focusing on the daily load profiles of energy demand for heating of Danish dwellings with heat pumps. Based on hourly recordings from 139 dwellings and employing cluster and regression analysis, the paper explores patterns...... (typologies) in daily heating load profiles and how these relate to socio-economic and technical characteristics of the included households. The study shows that the load profiles vary according to the external load conditions. Two main clusters were identified for both weekdays and weekends and across load...

Load evaluation of the da Vinci surgical system for transoral robotic surgery.

Science.gov (United States)

Fujiwara, Kazunori; Fukuhara, Takahiro; Niimi, Koji; Sato, Takahiro; Kitano, Hiroya

2015-12-01

Transoral robotic surgery, performed with the da Vinci surgical system (da Vinci), is a surgical approach for benign and malignant lesions of the oral cavity and laryngopharynx. It provides several unique advantages, which include a 3-dimensional magnified view and ability to see and work around curves or angles. However, the current da Vinci surgical system does not provide haptic feedback. This is problematic because the potential risks specific to the transoral use of the da Vinci include tooth injury, mucosal laceration, ocular injury and mandibular fracture. To assess the potential for intraoperative injuries, we measured the load of the endoscope and the instrument of the da Vinci Si surgical system. We pressed the endoscope and instrument of the da Vinci Si against Load cell six times each and measured the dynamic load and the time-to-maximum load. We also struck the da Vinci Si endoscope and instrument against the Load cell six times each and measured the impact load. The maximum dynamic load was 7.27 ± 1.31 kg for the endoscope and 1.90 ± 0.72 for the instrument. The corresponding time-to-maximum loads were 1.72 ± 0.22 and 1.29 ± 0.34 s, but the impact loads were significantly lower than the dynamic load. It remains possible that a major load is exerted on adjacent structures by continuous contact with the endoscope and instrument of da Vinci Si. However, there is a minor delay in reaching the maximum load. Careful monitoring by an on-site assistant may, therefore, help prevent contiguous injury.

Selecting boundary conditions in physiological strain analysis of the femur: Balanced loads, inertia relief method and follower load.

Science.gov (United States)

Heyland, Mark; Trepczynski, Adam; Duda, Georg N; Zehn, Manfred; Schaser, Klaus-Dieter; Märdian, Sven

2015-12-01

Selection of boundary constraints may influence amount and distribution of loads. The purpose of this study is to analyze the potential of inertia relief and follower load to maintain the effects of musculoskeletal loads even under large deflections in patient specific finite element models of intact or fractured bone compared to empiric boundary constraints which have been shown to lead to physiological displacements and surface strains. The goal is to elucidate the use of boundary conditions in strain analyses of bones. Finite element models of the intact femur and a model of clinically relevant fracture stabilization by locking plate fixation were analyzed with normal walking loading conditions for different boundary conditions, specifically re-balanced loading, inertia relief and follower load. Peak principal cortex surface strains for different boundary conditions are consistent (maximum deviation 13.7%) except for inertia relief without force balancing (maximum deviation 108.4%). Influence of follower load on displacements increases with higher deflection in fracture model (from 3% to 7% for force balanced model). For load balanced models, follower load had only minor influence, though the effect increases strongly with higher deflection. Conventional constraints of fixed nodes in space should be carefully reconsidered because their type and position are challenging to justify and for their potential to introduce relevant non-physiological reaction forces. Inertia relief provides an alternative method which yields physiological strain results. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

Maximum stress estimation model for multi-span waler beams with deflections at the supports using average strains.

Science.gov (United States)

Park, Sung Woo; Oh, Byung Kwan; Park, Hyo Seon

2015-03-30

The safety of a multi-span waler beam subjected simultaneously to a distributed load and deflections at its supports can be secured by limiting the maximum stress of the beam to a specific value to prevent the beam from reaching a limit state for failure or collapse. Despite the fact that the vast majority of accidents on construction sites occur at waler beams in retaining wall systems, no safety monitoring model that can consider deflections at the supports of the beam is available. In this paper, a maximum stress estimation model for a waler beam based on average strains measured from vibrating wire strain gauges (VWSGs), the most frequently used sensors in construction field, is presented. The model is derived by defining the relationship between the maximum stress and the average strains measured from VWSGs. In addition to the maximum stress, support reactions, deflections at supports, and the magnitudes of distributed loads for the beam structure can be identified by the estimation model using the average strains. Using simulation tests on two multi-span beams, the performance of the model is evaluated by estimating maximum stress, deflections at supports, support reactions, and the magnitudes of distributed loads.

The Circadian Clock Modulates Global Daily Cycles of mRNA Ribosome Loading[OPEN

Science.gov (United States)

Missra, Anamika; Ernest, Ben; Jia, Qidong; Ke, Kenneth

2015-01-01

Circadian control of gene expression is well characterized at the transcriptional level, but little is known about diel or circadian control of translation. Genome-wide translation state profiling of mRNAs in Arabidopsis thaliana seedlings grown in long day was performed to estimate ribosome loading per mRNA. The experiments revealed extensive translational regulation of key biological processes. Notably, translation of mRNAs for ribosomal proteins and mitochondrial respiration peaked at night. Central clock mRNAs are among those subject to fluctuations in ribosome loading. There was no consistent phase relationship between peak translation states and peak transcript levels. The overlay of distinct transcriptional and translational cycles can be expected to alter the waveform of the protein synthesis rate. Plants that constitutively overexpress the clock gene CCA1 showed phase shifts in peak translation, with a 6-h delay from midnight to dawn or from noon to evening being particularly common. Moreover, cycles of ribosome loading that were detected under continuous light in the wild type collapsed in the CCA1 overexpressor. Finally, at the transcript level, the CCA1-ox strain adopted a global pattern of transcript abundance that was broadly correlated with the light-dark environment. Altogether, these data demonstrate that gene-specific diel cycles of ribosome loading are controlled in part by the circadian clock. PMID:26392078

Probabilistic model of bridge vehicle loads in port area based on in-situ load testing

Science.gov (United States)

Deng, Ming; Wang, Lei; Zhang, Jianren; Wang, Rei; Yan, Yanhong

2017-11-01

Vehicle load is an important factor affecting the safety and usability of bridges. An statistical analysis is carried out in this paper to investigate the vehicle load data of Tianjin Haibin highway in Tianjin port of China, which are collected by the Weigh-in- Motion (WIM) system. Following this, the effect of the vehicle load on test bridge is calculated, and then compared with the calculation result according to HL-93(AASHTO LRFD). Results show that the overall vehicle load follows a distribution with a weighted sum of four normal distributions. The maximum vehicle load during the design reference period follows a type I extremum distribution. The vehicle load effect also follows a weighted sum of four normal distributions, and the standard value of the vehicle load is recommended as 1.8 times that of the calculated value according to HL-93.

Temporal Variability of Daily Personal Magnetic Field Exposure Metrics in Pregnant Women

OpenAIRE

Lewis, Ryan C.; Evenson, Kelly R.; Savitz, David A.; Meeker, John D.

2014-01-01

Recent epidemiology studies of power-frequency magnetic fields and reproductive health have characterized exposures using data collected from personal exposure monitors over a single day, possibly resulting in exposure misclassification due to temporal variability in daily personal magnetic field exposure metrics, but relevant data in adults are limited. We assessed the temporal variability of daily central tendency (time-weighted average, median) and peak (upper percentiles, maximum) persona...

Gridded 5km GHCN-Daily Temperature and Precipitation Dataset, Version 1

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Gridded 5km GHCN-Daily Temperature and Precipitation Dataset (nClimGrid) consists of four climate variables derived from the GHCN-D dataset: maximum temperature,...

Climate Prediction Center(CPC)Daily U.S. Precipitation and Temperature Summary

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Daily U.S. minimum and maximum temperatures in whole degrees Fahrenheit and reported and estimated precipitation amounts in hundredths of inches(ex 100 is 1.00...

The role of grid-connected, building-integrated photovoltaic generation in commercial building energy and power loads in a warm and sunny climate

International Nuclear Information System (INIS)

Braun, P.; Ruether, R.

2010-01-01

For large commercial buildings, power load delivery limits are contracted with the local electricity distribution utility, and are usually fixed at one or more levels over the year, according to the seasonal building loads, and depending on the specific country regulations. Especially in warm and sunny climates, solar electricity generation using building-integrated photovoltaics (BIPV) can assist in reducing commercial building loads, offering peak-shaving (power) benefits on top of the on-site generation of electricity (energy). This on-site power delivery capability gives these consumers the possibility of renegotiating demand contracts with their distribution utility. Commercial buildings that operate during daytime quite often have an energy consumption profile that is well matched by solar radiation availability, and depending on the building's available surface areas, BIPV can generate considerable portions of the energy requirements. In this work we present the role of grid-connected BIPV in reducing the load demands of a large and urban commercial building located in a warm climate in Brazil. The building and adjacent car parking lots can accommodate a 1 MWp BIPV generator, which closely matches the building's typical maximum power demands. Based on real solar radiation data and simultaneous building electricity demands for the year 2007, simulation of the annual solar generation profile of this on-site generator showed that the 1 MWp BIPV system could account for around 30% of the total building's energy consumption. In addition to the energy benefit, maximum power demands were reduced due to a good match between midday air-conditioning cooling loads and solar radiation availability on both a daily and seasonal basis. Furthermore, we have simulated the effect of this considerably large urban-sited generator on the local distribution network load, and have shown that the 1 MWp BIPV installation can also offer considerable benefits to the local utility in

Vitamin D supplementation in nursing home patients: randomized controlled trial of standard daily dose versus individualized loading dose regimen.

Science.gov (United States)

Wijnen, Hugo; Salemink, Dayenne; Roovers, Lian; Taekema, Diana; de Boer, Hans

2015-05-01

Supplementation of cholecalciferol 800 IU daily appears to be insufficient to raise vitamin D levels to >75 nmol/l in nursing home (NH) patients. Our objective was to compare the efficacy of an individualized cholecalciferol loading dose (LD) regimen and a daily dose (DD) regimen of cholecalciferol 800 IU in reaching 25-OH vitamin D (25OHD) levels >75 nmol/l. A total of 30 NH patients with 25OHD levels 50 nmol/l were included. Patients were randomized using the minimization method in the LD or DD group. The cholecalciferol LD, calculated with an algorithm based on serum 25OHD level and body weight, was administered in divided doses of 50,000 IU twice a week, followed by a monthly maintenance dose of either 50,000 or 25,000 IU. The DD regimen consisted of cholecalciferol 800 IU daily for 26 weeks. Serum 25OHD, calcium, creatinine, phosphate, and parathyroid hormone were measured, and 2-minute walking test, handgrip strength, and timed get up and go test were assessed at baseline (T 0), after 5 weeks (T 5), 12 weeks (T 12), and 26 weeks (T 26). The primary endpoint was the percentage of patients with 25OHD levels >75 nmol/l at T 5. Secondary endpoints were the proportion of patients with 25OHD levels >75 nmol/l at T 26, safety of LD regimen, and improvement of performance tests with normalization of vitamin D levels. Median baseline 25OHD levels (interquartile range) were comparable between the 14 DD and 16 LD patients: 20.9 (15.9-29.6) and 21.7 (16.4-32.8) nmol/l, respectively. Levels of 25OHD >75 nmol/l at T 5 were reached in 79 % of the 14 LD patients, but in none of the 13 DD patients (p 75 nmol/l were reached in 83 % of the 12 LD patients and in 30 % of the ten DD patients (p tests was observed. In NH patients with severe 25OHD deficiency, an individualized calculated cholecalciferol LD is likely to be superior to a DD of cholecalciferol 800 IU in terms of the ability to rapidly normalize vitamin D levels.

The load structure of electro boilers

International Nuclear Information System (INIS)

Feilberg, N.; Livik, K.

1995-01-01

Load measurements have been performed on 24 electro boilers with a time resolution of one hour throughout a period of one year. The boilers are used for space heating and heating of tap water in office buildings, shopping centres and apartment buildings. All boilers have tariffs with disconnection agreements. This report presents load analyses of the measurements from each boiler, and typical load profiles are calculated and presented. It also analyses how boilers are used in relation to the outdoor temperature and the power price on the spot market. All the measurements are performed in Bergen, Norway, in the period August 1993 - August 1994. Typical load profiles are shown, both annual and daily, as well as specific load parameters in addition to key figures used in calculating the total power load on the distribution network. The climate impact on energy and power load is evaluated. The report also shows examples of how the results may be applied in various special fields. 8 figs., 9 tabs

Stochastic Extreme Load Predictions for Marine Structures

DEFF Research Database (Denmark)

Jensen, Jørgen Juncher

1999-01-01

Development of rational design criteria for marine structures requires reliable estimates for the maximum wave-induced loads the structure may encounter during its operational lifetime. The paper discusses various methods for extreme value predictions taking into account the non-linearity of the ......Development of rational design criteria for marine structures requires reliable estimates for the maximum wave-induced loads the structure may encounter during its operational lifetime. The paper discusses various methods for extreme value predictions taking into account the non......-linearity of the waves and the response. As example the wave-induced bending moment in the ship hull girder is considered....

Gas-Induced Water-hammer Loads Calculation for Safety Related Systems

Energy Technology Data Exchange (ETDEWEB)

Lee, Seungchan; Yoon, Dukjoo [Korea Hydro and Nuclear Power Co., LTd, Daejeon (Korea, Republic of); Lee, Dooyong [Seoul National Univ., Seoul (Korea, Republic of)

2013-05-15

Of particular interest, gas accumulation can result in system pressure transient in pump discharge piping following a pump start. Consequently, this evolves into a gas-water, a water-hammer event and the accompanying force imbalances on the piping segments can be sufficient to challenge the piping supports and restraint. This paper describes an method performing to the water-hammer loads to determine the maximum loading that would occur in the piping system following the safety injection signal and to evaluate its integrity. For a given gas void volumes in the discharge piping, the result of the calculation shows the maximum loads of 18,894.2psi, which is smaller than the allowable criteria. Also, the maximum peak axial force imbalances acting on the support is 1,720lbf as above.

Gas-Induced Water-hammer Loads Calculation for Safety Related Systems

International Nuclear Information System (INIS)

Lee, Seungchan; Yoon, Dukjoo; Lee, Dooyong

2013-01-01

Of particular interest, gas accumulation can result in system pressure transient in pump discharge piping following a pump start. Consequently, this evolves into a gas-water, a water-hammer event and the accompanying force imbalances on the piping segments can be sufficient to challenge the piping supports and restraint. This paper describes an method performing to the water-hammer loads to determine the maximum loading that would occur in the piping system following the safety injection signal and to evaluate its integrity. For a given gas void volumes in the discharge piping, the result of the calculation shows the maximum loads of 18,894.2psi, which is smaller than the allowable criteria. Also, the maximum peak axial force imbalances acting on the support is 1,720lbf as above

Designing an application for managing distribution transformer load

Directory of Open Access Journals (Sweden)

Olga Liliana Sánchez

2006-09-01

Full Text Available This paper presents a software application for distribution transformer load management and calculating the elec- tricity distribution network service quality index (i.e. EDS and EFS indexes. Transformer operation state, calculating core and coil losses and selecting distribution transformers based on technical-economic criteria using daily-load curves are the load management strategies presented here. The application consists of a programme allowing to data acquisition input, an Excel-based spread-sheet having the equations for calculating load management data and a user-interface presenting the load management application’s results. The application was validated by technical-economic evaluation of three distribution transformers when supplying demand.

The effect of low-load exercise on joint pain, function, and activities of daily living in patients with knee osteoarthritis.

Science.gov (United States)

Peeler, Jason; Ripat, Jacquie

2018-01-01

Knee osteoarthritis has a lifetime risk of nearly one in two, with obese individuals being most susceptible. While exercise is universally recognized as a critical component for management, unsafe or ineffective exercise frequently leads to exacerbation of joint symptoms. Evaluate the effect of a 12week lower body positive pressure (LBPP) supported low-load treadmill walking program on knee pain, joint function, and performance of daily activities in patients with knee osteoarthritis (OA). Prospective, observational, repeated measures investigation. Community based, multidisciplinary musculoskeletal medicine clinic. Thirty-one patients, aged 50-75, with a BMI ≥25kg/m 2 and radiographic confirmed mild to moderate knee OA. Twelve week LBPP treadmill walking exercise regimen. The Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Canadian Occupational Performance Measure (COPM) were used to quantify joint symptoms and patient function; isokinetic thigh muscle strength was evaluated; and a 10-point VAS was used to quantify acute knee pain while walking. Baseline and follow-up data were compared in order to examine the effect of the 12week exercise intervention. There was a significant difference between baseline and follow-up data: KOOS and COPM scores both improved; thigh muscle strength increased; and acute knee pain during full weight bearing walking diminished significantly. Participation in a 12week LBPP supported treadmill walking exercise regimen significantly enhanced patient function and quality of life, as well as the ability to perform activities of daily living that patient's self-identified as being important, yet difficult to perform. Copyright © 2017 Elsevier B.V. All rights reserved.

Predicting the Maximum Dynamic Strength in Bench Press: The High Precision of the Bar Velocity Approach.

Science.gov (United States)

Loturco, Irineu; Kobal, Ronaldo; Moraes, José E; Kitamura, Katia; Cal Abad, César C; Pereira, Lucas A; Nakamura, Fábio Y

2017-04-01

Loturco, I, Kobal, R, Moraes, JE, Kitamura, K, Cal Abad, CC, Pereira, LA, and Nakamura, FY. Predicting the maximum dynamic strength in bench press: the high precision of the bar velocity approach. J Strength Cond Res 31(4): 1127-1131, 2017-The aim of this study was to determine the force-velocity relationship and test the possibility of determining the 1 repetition maximum (1RM) in "free weight" and Smith machine bench presses. Thirty-six male top-level athletes from 3 different sports were submitted to a standardized 1RM bench press assessment (free weight or Smith machine, in randomized order), following standard procedures encompassing lifts performed at 40-100% of 1RM. The mean propulsive velocity (MPV) was measured in all attempts. A linear regression was performed to establish the relationships between bar velocities and 1RM percentages. The actual and predicted 1RM for each exercise were compared using a paired t-test. Although the Smith machine 1RM was higher (10% difference) than the free weight 1RM, in both cases the actual and predicted values did not differ. In addition, the linear relationship between MPV and percentage of 1RM (coefficient of determination ≥95%) allow determination of training intensity based on the bar velocity. The linear relationships between the MPVs and the relative percentages of 1RM throughout the entire range of loads enable coaches to use the MPV to accurately monitor their athletes on a daily basis and accurately determine their actual 1RM without the need to perform standard maximum dynamic strength assessments.

Load leveling total system. Part 2. Development of load leveling logic for residential customer; Fuka heijunka total system. 2. Kateiyo juyoka wo taisho to shita heijunka ronri no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Asari, M.; Nanahara, T. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

1995-05-01

It is essential, in order to meet steadily increasing demands for electrical power, to develop techniques for effective utilization of energy and load leveling. Described herein is development, by the aid of linear programming, of logic for daily management of charge/discharge of load conditioners and reverse power flow, for predicted loads and patterns of power generated by photovoltaic cells installed at individual customers. It is aimed at minimizing power rate and leveling of load at distribution systems. Predicted loads, outputs by photovoltaic cell units and different power rates by time zone for the next day are inputted, to determine the charge/discharge schedules and power supply/reverse flow patterns for that day, in order to minimize power rates and level loads at higher hierarchical levels. The logic-aided daily simulation for various districts confirms the operational patterns that realize improved utilization of pole-mounted transformers while reducing costs at customers, and effects of prediction errors. 4 refs., 14 figs.

Energetics of load carrying in Nepalese porters.

Science.gov (United States)

Bastien, Guillaume J; Schepens, Bénédicte; Willems, Patrick A; Heglund, Norman C

2005-06-17

Nepalese porters routinely carry head-supported loads equal to 100 to 200% of their body weight (Mb) for many days up and down steep mountain footpaths at high altitudes. Previous studies have shown that African women carry head-supported loads of up to 60% of their Mb far more economically than army recruits carrying equivalent loads in backpacks. Here we show that Nepalese porters carry heavier loads even more economically than African women. Female Nepalese porters, for example, carry on average loads that are 10% of their Mb heavier than the maximum loads carried by the African women, yet do so at a 25% smaller metabolic cost.

Recent Developments in Maximum Power Point Tracking Technologies for Photovoltaic Systems

Directory of Open Access Journals (Sweden)

Nevzat Onat

2010-01-01

Full Text Available In photovoltaic (PV system applications, it is very important to design a system for operating of the solar cells (SCs under best conditions and highest efficiency. Maximum power point (MPP varies depending on the angle of sunlight on the surface of the panel and cell temperature. Hence, the operating point of the load is not always MPP of PV system. Therefore, in order to supply reliable energy to the load, PV systems are designed to include more than the required number of modules. The solution to this problem is that switching power converters are used, that is called maximum power point tracker (MPPT. In this study, the various aspects of these algorithms have been analyzed in detail. Classifications, definitions, and basic equations of the most widely used MPPT technologies are given. Moreover, a comparison was made in the conclusion.

Maximum And Minimum Temperature Trends In Mexico For The Last 31 Years

Science.gov (United States)

Romero-Centeno, R.; Zavala-Hidalgo, J.; Allende Arandia, M. E.; Carrasco-Mijarez, N.; Calderon-Bustamante, O.

2013-05-01

Based on high-resolution (1') daily maps of the maximum and minimum temperatures in Mexico, an analysis of the last 31-year trends is performed. The maps were generated using all the available information from more than 5,000 stations of the Mexican Weather Service (Servicio Meteorológico Nacional, SMN) for the period 1979-2009, along with data from the North American Regional Reanalysis (NARR). The data processing procedure includes a quality control step, in order to eliminate erroneous daily data, and make use of a high-resolution digital elevation model (from GEBCO), the relationship between air temperature and elevation by means of the average environmental lapse rate, and interpolation algorithms (linear and inverse-distance weighting). Based on the monthly gridded maps for the mentioned period, the maximum and minimum temperature trends calculated by least-squares linear regression and their statistical significance are obtained and discussed.

Influence of different outdoor design conditions on design cooling load and design capacities of air conditioning equipments

International Nuclear Information System (INIS)

Aktacir, Mehmet Azmi; Bueyuekalaca, Orhan; Bulut, Huesamettin; Yilmaz, Tuncay

2008-01-01

Outdoor design conditions are important parameters for energy efficiency of buildings. The result of incorrect selection of outdoor design conditions can be dramatic in view of comfort and energy consumption. In this study, the influence of different outdoor design conditions on air conditioning systems is investigated. For this purpose, cooling loads and capacities of air conditioning equipments for a sample building located in Adana, Turkey are calculated using different outdoor design conditions recommended by ASHRAE, the current design data used in Turkey and the daily maximum dry and wet bulb temperatures of July 21st, which is generally accepted as the design day. The cooling coil capacities obtained from the different outdoor design conditions considered in this study are compared with each other. The cost analysis of air conditioning systems is also performed. It is seen that the selection of outdoor design conditions is a very critical step in calculation of the building cooling loads and design capacities of air conditioning equipments

Influence of Poly-(L-Lactic Acid Nanofiber Functionalization on Maximum Load, Young's Modulus, and Strain of Nanofiber Scaffolds Before and After Cultivation of Osteoblasts: An In Vitro Study

Directory of Open Access Journals (Sweden)

Jürgen Paletta

2009-01-01

Full Text Available The aim of this study was to characterize the influence of functionalization of synthetic poly-(L-lactic acid (PLLA nanofibers on mechanical properties such as maximum load, elongation, and Young's modulus. Furthermore, the impact of osteoblast growth on the various nanofiber scaffolds stability was determined. Nanofiber matrices composed of PLLA, PLLA-collagen, or BMP-2–incorporated PLLA were produced from different solvents by electrospinning. Standardized test samples of each nanofiber scaffold were subjected to failure protocol before or after incubation in the presence of osteoblasts over a period of 22 days under osteoinductive conditions. PLLA nanofibers electrospun from hexafluoroisopropanol (HFIP showed a higher strain and tended to have increased maximum loads and Young's modulus compared to PLLA fibers spun from dichloromethane. In addition, they had a higher resistance during incubation in the presence of cells. Functionalization by incorporation of growth factors increased Young's modulus, independent of the solvent used. However, the incorporation of growth factors using the HFIP system resulted in a loss of strain. Similar results were observed when PLLA was blended with different ratios of collagen. Summarizing the results, this study indicates that different functionalization strategies influence the mechanical stability of PLLA nanofibers. Therefore, an optimization of nanofibers should not only account for the optimization of biological effects on cells, but also has to consider the stability of the scaffold.

Maximum Stress Estimation Model for Multi-Span Waler Beams with Deflections at the Supports Using Average Strains

Directory of Open Access Journals (Sweden)

Sung Woo Park

2015-03-01

Full Text Available The safety of a multi-span waler beam subjected simultaneously to a distributed load and deflections at its supports can be secured by limiting the maximum stress of the beam to a specific value to prevent the beam from reaching a limit state for failure or collapse. Despite the fact that the vast majority of accidents on construction sites occur at waler beams in retaining wall systems, no safety monitoring model that can consider deflections at the supports of the beam is available. In this paper, a maximum stress estimation model for a waler beam based on average strains measured from vibrating wire strain gauges (VWSGs, the most frequently used sensors in construction field, is presented. The model is derived by defining the relationship between the maximum stress and the average strains measured from VWSGs. In addition to the maximum stress, support reactions, deflections at supports, and the magnitudes of distributed loads for the beam structure can be identified by the estimation model using the average strains. Using simulation tests on two multi-span beams, the performance of the model is evaluated by estimating maximum stress, deflections at supports, support reactions, and the magnitudes of distributed loads.

Efficiency of Photovoltaic Maximum Power Point Tracking Controller Based on a Fuzzy Logic

Directory of Open Access Journals (Sweden)

Ammar Al-Gizi

2017-07-01

Full Text Available This paper examines the efficiency of a fuzzy logic control (FLC based maximum power point tracking (MPPT of a photovoltaic (PV system under variable climate conditions and connected load requirements. The PV system including a PV module BP SX150S, buck-boost DC-DC converter, MPPT, and a resistive load is modeled and simulated using Matlab/Simulink package. In order to compare the performance of FLC-based MPPT controller with the conventional perturb and observe (P&O method at different irradiation (G, temperature (T and connected load (RL variations – rising time (tr, recovering time, total average power and MPPT efficiency topics are calculated. The simulation results show that the FLC-based MPPT method can quickly track the maximum power point (MPP of the PV module at the transient state and effectively eliminates the power oscillation around the MPP of the PV module at steady state, hence more average power can be extracted, in comparison with the conventional P&O method.

Probability Distribution and Projected Trends of Daily Precipitation in China

Institute of Scientific and Technical Information of China (English)

CAO; Li-Ge; ZHONG; Jun; SU; Bu-Da; ZHAI; Jian-Qing; Macro; GEMMER

2013-01-01

Based on observed daily precipitation data of 540 stations and 3,839 gridded data from the high-resolution regional climate model COSMO-Climate Limited-area Modeling(CCLM)for 1961–2000,the simulation ability of CCLM on daily precipitation in China is examined,and the variation of daily precipitation distribution pattern is revealed.By applying the probability distribution and extreme value theory to the projected daily precipitation(2011–2050)under SRES A1B scenario with CCLM,trends of daily precipitation series and daily precipitation extremes are analyzed.Results show that except for the western Qinghai-Tibetan Plateau and South China,distribution patterns of the kurtosis and skewness calculated from the simulated and observed series are consistent with each other;their spatial correlation coefcients are above 0.75.The CCLM can well capture the distribution characteristics of daily precipitation over China.It is projected that in some parts of the Jianghuai region,central-eastern Northeast China and Inner Mongolia,the kurtosis and skewness will increase significantly,and precipitation extremes will increase during 2011–2050.The projected increase of maximum daily rainfall and longest non-precipitation period during flood season in the aforementioned regions,also show increasing trends of droughts and floods in the next 40 years.

Measurement of in-bore side loads and comparison to first maximum yaw

Directory of Open Access Journals (Sweden)

Donald E. Carlucci

2016-04-01

Full Text Available In-bore yaw of a projectile in a gun tube has been shown to result in range loss if the yaw is significant. An attempt was made to determine if relationships between in-bore yaw and projectile First Maximum Yaw (FMY were observable. Experiments were conducted in which pressure transducers were mounted near the muzzle of a 155 mm cannon in three sets of four. Each set formed a cruciform pattern to obtain a differential pressure across the projectile. These data were then integrated to form a picture of what the overall pressure distribution was along the side of the projectile. The pressure distribution was used to determine a magnitude and direction of the overturning moment acting on the projectile. This moment and its resulting angular acceleration were then compared to the actual first maximum yaw observed in the test. The degree of correlation was examined using various statistical techniques. Overall uncertainty in the projectile dynamics was between 20% and 40% of the mean values of FMY.

Estimation of daily solar radiation from routinely observed meteorological data in Chongqing, China

International Nuclear Information System (INIS)

Li Maofen; Liu Hongbin; Guo Pengtao; Wu Wei

2010-01-01

Solar radiation is a very important and major variable in crop simulation models. However, it is measured at a very limited number of meteorological stations worldwide. Models were developed to estimate daily solar radiation in Chongqing, one of the most important agricultural areas in China. Several routinely observed meteorological variables including daily maximum and minimum temperatures, daily mean dew point temperature, fog and rainfall had been obtained, investigated and analyzed from 1986 to 2000 for Chongqing. The monthly mean daily solar radiation at this location ranged from a maximum of 15.082 MJ m -2 day -1 in August and a minimum of 3.042 MJ m -2 day -1 in December. A newly developed model that included all selected variables proved the best method with a RMSE value of 2.522 MJ m -2 day -1 . The best performed models for different seasons were further evaluated according to divide-and-conquer principle. The model using all selected variables provided the best estimates of daily solar radiation in winter and autumn with RMSE values of 1.491 and 2.037 MJ m -2 day -1 , respectively. The method involving temperatures and rainfall information could be used to estimate daily solar radiation in summer with a RMSE value of 3.163 MJ m -2 day -1 . The model using temperature, rainfall and dew point data performed better than other models in spring with a RMSE value of 2.910 MJ m -2 day -1 .

The effectiveness of reducing the daily dose of finasteride in men with benign prostatic hyperplasia

Directory of Open Access Journals (Sweden)

Geller Jack

2002-01-01

Full Text Available Abstract Background Finasteride, a 5 alpha reductase inhibitor, is an established treatment for benign prostatic hyperplasia. The recommended dosage is 5 mg a day, however case reports have show effectiveness with lower doses. The objective of the current study was to determine in men with benign prostatic hyperplasia, previously treated for at least one year with finasteride 5 mg daily, if they will maintain subjective and objective improvements in urinary obstruction when treated with 2.5 mg of finasteride daily for one year. Methods In an open label, prospective study, 40 men with benign prostatic hyperplasia, previously treated for at least one year with 5 mg of finasteride, took 2.5 mg of finasteride daily for one year. Measurements included AUA symptom score, maximum flow rate, voided volume and PSA. Results There were no significant changes in maximum flow rate, voided volume, or AUA symptom score after one year of finasteride 2.5 mg daily therapy. PSA increased significantly, p Conclusions The daily dose of finasteride can be reduced to 2.5 mg daily without significant effect on subjective and objective measures of urinary obstruction. Although statistically significant increases in PSA are noted when reducing the daily finasteride dose from 5 mg to 2.5 mg, the clinical significance of a mean .6 ng/ml increase in PSA is questionable.

Biomechanical optimization of implant diameter and length for immediate loading: a nonlinear finite element analysis.

Science.gov (United States)

Kong, Liang; Gu, Zexu; Li, Tao; Wu, Junjie; Hu, Kaijin; Liu, Yanpu; Zhou, Hongzhi; Liu, Baolin

2009-01-01

A nonlinear finite element method was applied to examine the effects of implant diameter and length on the maximum von Mises stresses in the jaw, and to evaluate the maximum displacement of the implant-abutment complex in immediate-loading models. The implant diameter (D) ranged from 3.0 to 5.0 mm and implant length (L) ranged from 6.0 to 16.0 mm. The results showed that the maximum von Mises stress in cortical bone was decreased by 65.8% under a buccolingual load with an increase in D. In cancellous bone, it was decreased by 71.5% under an axial load with an increase in L. The maximum displacement in the implant-abutment complex decreased by 64.8% under a buccolingual load with an increase in D. The implant was found to be more sensitive to L than to D under axial loads, while D played a more important role in enhancing its stability under buccolingual loads. When D exceeded 4.0 mm and L exceeded 11.0 mm, both minimum stress and displacement were obtained. Therefore, these dimensions were the optimal biomechanical selections for immediate-loading implants in type B/2 bone.

Determining the optimal load for jump squats: a review of methods and calculations.

Science.gov (United States)

Dugan, Eric L; Doyle, Tim L A; Humphries, Brendan; Hasson, Christopher J; Newton, Robert U

2004-08-01

There has been an increasing volume of research focused on the load that elicits maximum power output during jump squats. Because of a lack of standardization for data collection and analysis protocols, results of much of this research are contradictory. The purpose of this paper is to examine why differing methods of data collection and analysis can lead to conflicting results for maximum power and associated optimal load. Six topics relevant to measurement and reporting of maximum power and optimal load are addressed: (a) data collection equipment, (b) inclusion or exclusion of body weight force in calculations of power, (c) free weight versus Smith machine jump squats, (d) reporting of average versus peak power, (e) reporting of load intensity, and (f) instructions given to athletes/ participants. Based on this information, a standardized protocol for data collection and reporting of jump squat power and optimal load is presented.

Energy saving in WWTP: Daily benchmarking under uncertainty and data availability limitations.

Science.gov (United States)

Torregrossa, D; Schutz, G; Cornelissen, A; Hernández-Sancho, F; Hansen, J

2016-07-01

Efficient management of Waste Water Treatment Plants (WWTPs) can produce significant environmental and economic benefits. Energy benchmarking can be used to compare WWTPs, identify targets and use these to improve their performance. Different authors have performed benchmark analysis on monthly or yearly basis but their approaches suffer from a time lag between an event, its detection, interpretation and potential actions. The availability of on-line measurement data on many WWTPs should theoretically enable the decrease of the management response time by daily benchmarking. Unfortunately this approach is often impossible because of limited data availability. This paper proposes a methodology to perform a daily benchmark analysis under database limitations. The methodology has been applied to the Energy Online System (EOS) developed in the framework of the project "INNERS" (INNovative Energy Recovery Strategies in the urban water cycle). EOS calculates a set of Key Performance Indicators (KPIs) for the evaluation of energy and process performances. In EOS, the energy KPIs take in consideration the pollutant load in order to enable the comparison between different plants. For example, EOS does not analyse the energy consumption but the energy consumption on pollutant load. This approach enables the comparison of performances for plants with different loads or for a single plant under different load conditions. The energy consumption is measured by on-line sensors, while the pollutant load is measured in the laboratory approximately every 14 days. Consequently, the unavailability of the water quality parameters is the limiting factor in calculating energy KPIs. In this paper, in order to overcome this limitation, the authors have developed a methodology to estimate the required parameters and manage the uncertainty in the estimation. By coupling the parameter estimation with an interval based benchmark approach, the authors propose an effective, fast and reproducible

Cognitive Load in Voice Therapy Carry-Over Exercises

DEFF Research Database (Denmark)

Iwarsson, Jenny; Morris, David Jackson; Balling, Laura Winther

2017-01-01

Purpose The cognitive load generated by online speech production may vary with the nature of the speech task. This article examines 3 speech tasks used in voice therapy carry-over exercises, in which a patient is required to adopt and automatize new voice behaviors, ultimately in daily spontaneous...... to automation of revised speech behavior and that self-reports may be a reliable index of cognitive load....

Model of analysis of maximum loads in wind generators produced by extreme winds

International Nuclear Information System (INIS)

Herrera – Sánchez, Omar; Schellong, Wolfgang; González – Fernández, Vladimir

2010-01-01

The use of the wind energy by means of the wind turbines in areas of high risk of occurrence of Hurricanes comes being an important challenge for the designers of wind farm at world for some years. The wind generator is not usually designed to support this type of phenomena, for this reason the areas of high incidence of tropical hurricanes of the planning are excluded, that which, in occasions disables the use of this renewable source of energy totally, either because the country is very small, or because it coincides the area of more potential fully with that of high risk. To counteract this situation, a model of analysis of maxims loads has been elaborated taken place the extreme winds in wind turbines of great behavior. This model has the advantage of determining, in a chosen place, for the installation of a wind farm, the micro-areas with higher risk of wind loads above the acceptable for the standard classes of wind turbines. (author)

Experimental And Theoretical Stress Analysis For Composite Plate Under Combined Load

Directory of Open Access Journals (Sweden)

Emad Qasim Hussein

2017-12-01

Full Text Available The combined effects of thermal and mechanical loadings on the distribution of stress-strain for E-glass fiber /polyester composite plates are investigated experimentally and numerically. The experimental work has been carried out by applying to a uniform temperature and tensile load on the composite plate inside the furnace and the deformation of plate measured by a dial gauge. Two parameter studies, the fiber volume fraction and fiber orientation on the stress-strain for plates subjected to identical mechanical and temperature gradient. The results presented showed that, the maximum absolute of total strain in longitudinal direction occurred at 50 N tension load and fiber angle 60º, while the minimum absolute values of it occurred at 15 N tension loads and fiber angle 0º. However the maximum absolute of total strain in transverse direction occurred at 15N tension load and fiber angle 0º, while the minimum absolute values of it are obtained at 50 N tension loads and fiber angle 60º. Also, the total strain in longitudinal and transverse direction decrease with increasing the fiber volume fraction. Comparison of the results in the experimental test with the numerical analysis of the total strain and evaluated the agreement between the two methods used, the maximum discrepancywas 20%.

Mathematical approach to the characterization of daily energy balance in autonomous photovoltaic solar systems

International Nuclear Information System (INIS)

Casares, F.J.; Lopez-Luque, R.; Posadillo, R.; Varo-Martinez, M.

2014-01-01

Sizing SAPV techniques try to assess the reliability of the system from the stochastic simulation of the energy balance. This stochastic simulation implies the generation, for an extended period of time, of the main state variables of the physical equations describing the energy balance of the system, that is, the energy delivered to the load and the energy stored in the batteries. Most of these methods consider the daily load as a constant over the year and control the variables indicating the reliability associated with the supply of power to the load. Furthermore, these methods rely on previous random models for generating solar radiation data and, since the approximations of the simulation methods are asymptotic, when more precise reliability indicators are required, the simulation period needs to be extended. This paper presents a mathematical methodology to address the daily energy balance without resorting to simulation methods. This method is directly based on daily solar radiation series modelled according to Markov stochastic processes and Aguiar matrices. The characterization presented is the base of a rational method in which reliability does not depend on the number of iterations but on the precision of the conditional probabilities included in Aguiar matrices. - Highlights: • A new SAPV sizing method is presented and validated. • This model relates the PV sizing methods to the autocorrelative Aguiar model. • This statistical approach is only limited by Markov matrixes. • It permits the study of PV systems with variable daily demands or solar tracking. • LLP for a SAPV can be estimated quickly and in an analytic and precise way

Equitable fund allocation, an economical approach for sustainable waste load allocation.

Science.gov (United States)

Ashtiani, Elham Feizi; Niksokhan, Mohammad Hossein; Jamshidi, Shervin

2015-08-01

This research aims to study a novel approach for waste load allocation (WLA) to meet environmental, economical, and equity objectives, simultaneously. For this purpose, based on a simulation-optimization model developed for Haraz River in north of Iran, the waste loads are allocated according to discharge permit market. The non-dominated solutions are initially achieved through multiobjective particle swarm optimization (MOPSO). Here, the violation of environmental standards based on dissolved oxygen (DO) versus biochemical oxidation demand (BOD) removal costs is minimized to find economical total maximum daily loads (TMDLs). This can save 41% in total abatement costs in comparison with the conventional command and control policy. The BOD discharge permit market then increases the revenues to 45%. This framework ensures that the environmental limits are fulfilled but the inequity index is rather high (about 4.65). For instance, the discharge permit buyer may not be satisfied about the equity of WLA. Consequently, it is recommended that a third party or institution should be in charge of reallocating the funds. It means that the polluters which gain benefits by unfair discharges should pay taxes (or funds) to compensate the losses of other polluters. This intends to reduce the costs below the required values of the lowest inequity index condition. These compensations of equitable fund allocation (EFA) may help to reduce the dissatisfactions and develop WLA policies. It is concluded that EFA in integration with water quality trading (WQT) is a promising approach to meet the objectives.

RPE vs. Percentage 1RM Loading in Periodized Programs Matched for Sets and Repetitions

Science.gov (United States)

Helms, Eric R.; Byrnes, Ryan K.; Cooke, Daniel M.; Haischer, Michael H.; Carzoli, Joseph P.; Johnson, Trevor K.; Cross, Matthew R.; Cronin, John B.; Storey, Adam G.; Zourdos, Michael C.

2018-01-01

Purpose: To investigate differences between rating of perceived exertion (RPE) and percentage one-repetition maximum (1RM) load assignment in resistance-trained males (19–35 years) performing protocols with matched sets and repetitions differentiated by load-assignment. Methods: Participants performed squats then bench press 3x/weeks in a daily undulating format over 8-weeks. Participants were counterbalanced by pre-test 1RM then assigned to percentage 1RM (1RMG, n = 11); load-assignment via percentage 1RMs, or RPE groups (RPEG, n = 10); participant-selected loads to reach target RPE ranges. Ultrasonography determined pre and post-test pectoralis (PMT), and vastus lateralis muscle thickness at 50 (VLMT50) and 70% (VLMT70) femur-length. Results: Bench press (1RMG +9.64 ± 5.36; RPEG + 10.70 ± 3.30 kg), squat (1RMG + 13.91 ± 5.89; RPEG + 17.05 ± 5.44 kg) and their combined-total 1RMs (1RMG + 23.55 ± 10.38; RPEG + 27.75 ± 7.94 kg) increased (p 0.05). Magnitude-based inferences revealed 79, 57, and 72% chances of mean small effect size (ES) advantages for squat; ES 90% confidence limits (CL) = 0.50 ± 0.63, bench press; ES 90% CL = 0.28 ± 0.73, and combined-total; ES 90% CL = 0.48 ± 0.68 respectively, in RPEG. There were 4, 14, and 6% chances 1RMG had a strength advantage of the same magnitude, and 18, 29, and 22% chances, respectively of trivial differences between groups. Conclusions: Both loading-types are effective. However, RPE-based loading may provide a small 1RM strength advantage in a majority of individuals. PMID:29628895

Load Balancing in Hypergraphs

Science.gov (United States)

Delgosha, Payam; Anantharam, Venkat

2018-03-01

Consider a simple locally finite hypergraph on a countable vertex set, where each edge represents one unit of load which should be distributed among the vertices defining the edge. An allocation of load is called balanced if load cannot be moved from a vertex to another that is carrying less load. We analyze the properties of balanced allocations of load. We extend the concept of balancedness from finite hypergraphs to their local weak limits in the sense of Benjamini and Schramm (Electron J Probab 6(23):13, 2001) and Aldous and Steele (in: Probability on discrete structures. Springer, Berlin, pp 1-72, 2004). To do this, we define a notion of unimodularity for hypergraphs which could be considered an extension of unimodularity in graphs. We give a variational formula for the balanced load distribution and, in particular, we characterize it in the special case of unimodular hypergraph Galton-Watson processes. Moreover, we prove the convergence of the maximum load under some conditions. Our work is an extension to hypergraphs of Anantharam and Salez (Ann Appl Probab 26(1):305-327, 2016), which considered load balancing in graphs, and is aimed at more comprehensively resolving conjectures of Hajek (IEEE Trans Inf Theory 36(6):1398-1414, 1990).

STUDY ON MAXIMUM SPECIFIC SLUDGE ACIVITY OF DIFFERENT ANAEROBIC GRANULAR SLUDGE BY BATCH TESTS

Institute of Scientific and Technical Information of China (English)

无

2001-01-01

The maximum specific sludge activity of granular sludge from large-scale UASB, IC and Biobed anaerobic reactors were investigated by batch tests. The limitation factors related to maximum specific sludge activity (diffusion, substrate sort, substrate concentration and granular size) were studied. The general principle and procedure for the precise measurement of maximum specific sludge activity were suggested. The potential capacity of loading rate of the IC and Biobed anaerobic reactors were analyzed and compared by use of the batch tests results.

A Novel Numerical Algorithm for Optimal Sizing of a Photovoltaic/Wind/Diesel Generator/Battery Microgrid Using Loss of Load Probability Index

Directory of Open Access Journals (Sweden)

Hussein A. Kazem

2013-01-01

Full Text Available This paper presents a method for determining optimal sizes of PV array, wind turbine, diesel generator, and storage battery installed in a building integrated system. The objective of the proposed optimization is to design the system that can supply a building load demand at minimum cost and maximum availability. The mathematical models for the system components as well as meteorological variables such as solar energy, temperature, and wind speed are employed for this purpose. Moreover, the results showed that the optimum sizing ratios (the daily energy generated by the source to the daily energy demand for the PV array, wind turbine, diesel generator, and battery for a system located in Sohar, Oman, are 0.737, 0.46, 0.22, and 0.17, respectively. A case study represented by a system consisting of 30 kWp PV array (36%, 18 kWp wind farm (55%, and 5 kVA diesel generator (9% is presented. This system is supposed to power a 200 kWh/day load demand. It is found that the generated energy share of the PV array, wind farm, and diesel generator is 36%, 55%, and 9%, respectively, while the cost of energy is 0.17 USD/kWh.

Wrist loading patterns during pommel horse exercises.

Science.gov (United States)

Markolf, K L; Shapiro, M S; Mandelbaum, B R; Teurlings, L

1990-01-01

Gymnastics is a sport which involves substantial periods of upper extremity support as well as frequent impacts to the wrist. Not surprisingly, wrist pain is a common finding in gymnasts. Of all events, the pommel horse is the most painful. In order to study the forces of wrist impact, a standard pommel horse was instrumented with a specially designed load cell to record the resultant force of the hand on the pommel during a series of basic skills performed by a group of seventeen elite male gymnasts. The highest mean peak forces were recorded during the front scissors and flair exercises (1.5 BW) with peaks of up to 2.0 BW for some gymnasts. The mean peak force for hip circles at the center or end of the horse was 1.1 BW. The mean overall loading rate (initial contact to first loading peak) ranged from 5.2 BWs-1 (hip circles) to 10.6 BW s-1 (flairs). However, many recordings displayed localized initial loading spikes which occurred during 'hard' landings on the pommel. When front scissors were performed in an aggressive manner, the initial loading spikes averaged 1.0 BW in magnitude (maximum 1.8 BW) with an average rise time of 8.2 ms; calculated localized loading rates averaged 129 BW s-1 (maximum 219 BW s-1). These loading parameters are comparable to those encountered at heel strike during running. These impact forces and loading rates are remarkably high for an upper extremity joint not normally exposed to weight-bearing loads, and may contribute to the pathogenesis of wrist injuries in gymnastics.

Limit load assessment of centre cracked plates under biaxial loading

International Nuclear Information System (INIS)

Meek, C.; Ainsworth, R.A.

2015-01-01

Fitness-for-service of equipment and components containing defects is generally assessed using procedures such as BS 7910, API 579 and R6. There is currently little detailed advice in these procedures on the effects of biaxial and triaxial loading on fracture. This poster shows some theoretical bounding solutions of the plastic limit load for centre cracked plates under a variety of biaxial loading ratios and compares the estimates with those found by numerical methods using finite element (FE) analysis using Abacus CAE modelling software. The limit load of a structure is the maximum load that it can carry before plastic collapse occurs; this is often when the plastic zone has become large enough to spread from the crack tip to a remote boundary. For an elastic-perfectly plastic material, the irreversible deformation will continue at stresses no higher than the yield stress. The model for these limit load solutions is a bi-axially loaded plate of width 2W and height 2H, a centre crack of width 2a, acted on by remotely applied uniform stresses σ 2 perpendicular to the crack and Bσ 2 parallel to the crack, where B is the biaxial loading ratio, it means the ratio of the parallel to the perpendicular stress. A quarter plate of an elastic-perfectly plastic material has been modelled. The results show that an exact solution has been found for negative and low positive values of B. For B > 1, the lower bound solution is conservative for all values of a/W and B

Suspended-sediment loads in the lower Stillaguamish River, Snohomish County, Washington, 2014–15

Science.gov (United States)

Anderson, Scott A.; Curran, Christopher A.; Grossman, Eric E.

2017-08-03

Continuous records of discharge and turbidity at a U.S. Geological Survey (USGS) streamgage in the lower Stillaguamish River were paired with discrete measurements of suspended-sediment concentration (SSC) in order to estimate suspended-sediment loads over the water years 2014 and 2015. First, relations between turbidity and SSC were developed and used to translate the continuous turbidity record into a continuous estimate of SSC. Those concentrations were then used to predict suspended-sediment loads based on the current discharge record, reported at daily intervals. Alternative methods were used to in-fill a small number of days with either missing periods of turbidity or discharge records. Uncertainties in our predictions at daily and annual time scales were estimated based on the parameter uncertainties in our turbidity-SSC regressions. Daily loads ranged from as high as 121,000 tons during a large autumn storm to as low as –56 tons, when tidal return flow moved more sediment upstream than river discharge did downstream. Annual suspended-sediment loads for both water years were close to 1.4 ± 0.2 million tons.

A maximum power point tracking scheme for a 1kw stand-alone ...

African Journals Online (AJOL)

A maximum power point tracking scheme for a 1kw stand-alone solar energy based power supply. ... Nigerian Journal of Technology ... A method for efficiently maximizing the output power of a solar panel supplying a load or battery bus under ...

Linear stochastic models for forecasting daily maxima and hourly concentrations of air pollutants

Energy Technology Data Exchange (ETDEWEB)

McCollister, G M; Wilson, K R

1975-04-01

Two related time series models were developed to forecast concentrations of various air pollutants and tested on carbon monoxide and oxidant data for the Los Angeles basin. One model forecasts daily maximum concentrations of a particular pollutant using only past daily maximum values of that pollutant as input. The other model forecasts 1 hr average concentrations using only the past hourly average values. Both are significantly more accurate than persistence, i.e., forecasting for tomorrow what occurred today (or yesterday). Model forecasts for 1972 of the daily instantaneous maxima for total oxidant made using only past pollutant concentration data are more accurate than those made by the Los Angeles APCD using meteorological input as well as pollutant concentrations. Although none of these models forecast as accurately as might be desired for a health warning system, the relative success of simple time series models, even though based solely on pollutant concentration, suggests that models incorporating meteorological data and using either multi-dimensional times series or pattern recognition techniques should be tested.

Load reduction test method of similarity theory and BP neural networks of large cranes

Science.gov (United States)

Yang, Ruigang; Duan, Zhibin; Lu, Yi; Wang, Lei; Xu, Gening

2016-01-01

Static load tests are an important means of supervising and detecting a crane's lift capacity. Due to space restrictions, however, there are difficulties and potential danger when testing large bridge cranes. To solve the loading problems of large-tonnage cranes during testing, an equivalency test is proposed based on the similarity theory and BP neural networks. The maximum stress and displacement of a large bridge crane is tested in small loads, combined with the training neural network of a similar structure crane through stress and displacement data which is collected by a physics simulation progressively loaded to a static load test load within the material scope of work. The maximum stress and displacement of a crane under a static load test load can be predicted through the relationship of stress, displacement, and load. By measuring the stress and displacement of small tonnage weights, the stress and displacement of large loads can be predicted, such as the maximum load capacity, which is 1.25 times the rated capacity. Experimental study shows that the load reduction test method can reflect the lift capacity of large bridge cranes. The load shedding predictive analysis for Sanxia 1200 t bridge crane test data indicates that when the load is 1.25 times the rated lifting capacity, the predicted displacement and actual displacement error is zero. The method solves the problem that lifting capacities are difficult to obtain and testing accidents are easily possible when 1.25 times related weight loads are tested for large tonnage cranes.

Fracture behaviour of a self-healing microcapsule-loaded epoxy system

Directory of Open Access Journals (Sweden)

2011-03-01

Full Text Available The effect of temperature on the fracture behaviour of a microcapsule-loaded epoxy matrix was investigated. Microencapsulated epoxy and mercaptan-derivative healing agents were incorporated into an epoxy matrix to produce a polymer composite capable of self-healing. Maximum fracture loads were measured using the double-torsion method. Thermal aging at 55 and 110°C for 17 hours [hrs] was applied to heal the pre-cracked samples. The addition of microcapsules appeared to increase significantly the load carrying capacity of the epoxy after healing. Once healed, the composites achieved as much as 93–171% of its virgin maximum fracture load at 18, 55 and 110°C. The fracture behavior of the microcapsule- loaded epoxy matrix was influenced by the healing temperature. The high self-healing efficiency may be attributed to the result of the subsurface micro-crack pinning or deviation, and to a stronger microencapsulated epoxy and mercaptanderivative binder than that of the bulk epoxy. The results show that the healing temperature has a significant effect on recovery of load transferring capability after fracture.

Loading pattern optimization with maximum utilization of discharging fuel employing adaptively constrained discontinuous penalty function

International Nuclear Information System (INIS)

Park, T. K.; Joo, H. G.; Kim, C. H.

2010-01-01

In order to find the most economical loading pattern (LP) considering multi-cycle fuel loading, multi-objective fuel LP optimization problems are examined by employing an adaptively constrained discontinuous penalty function (ACDPF) method. This is an improved method to simplify the complicated acceptance logic of the original DPF method in that the stochastic effects caused by the different random number sequence can be reduced. The effectiveness of the multi-objective simulated annealing (SA) algorithm employing ACDPF is examined for the reload core LP of Cycle 4 of Yonggwang Nuclear Unit 4. Several optimization runs are performed with different numbers of objectives consisting of cycle length and average burnup of fuels to be discharged or reloaded. The candidate LPs obtained from the multi-objective optimization runs turn out to be better than the reference LP in the aspects of cycle length and utilization of given fuels. It is note that the proposed ACDPF based MOSA algorithm can be a practical method to obtain an economical LP considering multi-cycle fuel loading. (authors)

Drivers of Intra-Summer Seasonality and Daily Variability of Coastal Low Cloudiness in California Subregions

Science.gov (United States)

Schwartz, R. E.; Iacobellis, S.; Gershunov, A.; Williams, P.; Cayan, D. R.

2014-12-01

Summertime low cloud intrusion into the terrestrial west coast of North America impacts human, ecological, and logistical systems. Over a broad region of the West Coast, summer (May - September) coastal low cloudiness (CLC) varies coherently on interannual to interdecadal timescales and has been found to be organized by North Pacific sea surface temperature. Broad-scale studies of low stratiform cloudiness over ocean basins also find that the season of maximum low stratus corresponds to the season of maximum lower tropospheric stability (LTS) or estimated inversion strength. We utilize a 18-summer record of CLC derived from NASA/NOAA Geostationary Operational Environmental Satellite (GOES) at 4km resolution over California (CA) to make a more nuanced spatial and temporal examination of intra-summer variability in CLC and its drivers. We find that uniform spatial coherency over CA is not apparent for intra-summer variability in CLC. On monthly to daily timescales, at least two distinct subregions of coastal California (CA) can be identified, where relationships between meteorology and stratus variability appear to change throughout summer in each subregion. While north of Point Conception and offshore the timing of maximum CLC is closely coincident with maximum LTS, in the Southern CA Bight and northern Baja region, maximum CLC occurs up to about a month before maximum LTS. It appears that summertime CLC in this southern region is not as strongly related as in the northern region to LTS. In particular, although the relationship is strong in May and June, starting in July the daily relationship between LTS and CLC in the south begins to deteriorate. Preliminary results indicate a moderate association between decreased CLC in the south and increased precipitable water content above 850 hPa on daily time scales beginning in July. Relationships between daily CLC variability and meteorological variables including winds, inland temperatures, relative humidity, and

The osteoporotic vertebral structure is well adapted to the loads of daily life, but not to infrequent "error" loads

NARCIS (Netherlands)

Homminga, J.J.; Rietbergen, van B.; Lochmüller, E.M.; Weinans, H.; Eckstein, F.; Huiskes, R.

2004-01-01

Osteoporotic vertebral fractures typically have a gradual onset, frequently remain clinically undetected, and do not seem to be related to traumatic events. The osteoporotic vertebrae may therefore be expected to display a less "optimal" bone architecture, leading to an uneven load distribution over

Theoretical assessment of the maximum power point tracking efficiency of photovoltaic facilities with different converter topologies

Energy Technology Data Exchange (ETDEWEB)

Enrique, J.M.; Duran, E.; Andujar, J.M. [Departamento de Ingenieria Electronica, de Sistemas Informaticos y Automatica, Universidad de Huelva (Spain); Sidrach-de-Cardona, M. [Departamento de Fisica Aplicada, II, Universidad de Malaga (Spain)

2007-01-15

The operating point of a photovoltaic generator that is connected to a load is determined by the intersection point of its characteristic curves. In general, this point is not the same as the generator's maximum power point. This difference means losses in the system performance. DC/DC converters together with maximum power point tracking systems (MPPT) are used to avoid these losses. Different algorithms have been proposed for maximum power point tracking. Nevertheless, the choice of the configuration of the right converter has not been studied so widely, although this choice, as demonstrated in this work, has an important influence in the optimum performance of the photovoltaic system. In this article, we conduct a study of the three basic topologies of DC/DC converters with resistive load connected to photovoltaic modules. This article demonstrates that there is a limitation in the system's performance according to the type of converter used. Two fundamental conclusions are derived from this study: (1) the buck-boost DC/DC converter topology is the only one which allows the follow-up of the PV module maximum power point regardless of temperature, irradiance and connected load and (2) the connection of a buck-boost DC/DC converter in a photovoltaic facility to the panel output could be a good practice to improve performance. (author)

Evaluation of Polyuria: The Roles of Solute Loading and Water Diuresis.

Science.gov (United States)

Bhasin, Bhavna; Velez, Juan Carlos Q

2016-03-01

Polyuria, defined as daily urine output in excess of 3.0 to 3.5L/d, can occur due to solute or water diuresis. Solute-induced polyuria can be seen in hospitalized patients after a high solute load from exogenous protein administration or following relief of urinary obstruction. Similar clinical scenarios are rarely encountered in the outpatient setting. We describe a case of polyuria due to high solute ingestion and excessive water intake leading to a mixed picture of solute and water diuresis. Restriction of the daily solute load and water intake resulted in complete resolution of polyuria. Determination of the daily excreted urinary osmoles may yield important clues to the cause of polyuria and should be included in the routine workup of polyuria. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Does shoe heel design influence ground reaction forces and knee moments during maximum lunges in elite and intermediate badminton players?

Directory of Open Access Journals (Sweden)

Wing-Kai Lam

Full Text Available Lunge is one frequently executed movement in badminton and involves a unique sagittal footstrike angle of more than 40 degrees at initial ground contact compared with other manoeuvres. This study examined if the shoe heel curvature design of a badminton shoe would influence shoe-ground kinematics, ground reaction forces, and knee moments during lunge.Eleven elite and fifteen intermediate players performed five left-forward maximum lunge trials with Rounded Heel Shoe (RHS, Flattened Heel Shoe (FHS, and Standard Heel Shoes (SHS. Shoe-ground kinematics, ground reaction forces, and knee moments were measured by using synchronized force platform and motion analysis system. A 2 (Group x 3 (Shoe ANOVA with repeated measures was performed to determine the effects of different shoes and different playing levels, as well as the interaction of two factors on all variables.Shoe effect indicated that players demonstrated lower maximum vertical loading rate in RHS than the other two shoes (P < 0.05. Group effect revealed that elite players exhibited larger footstrike angle, faster approaching speed, lower peak horizontal force and horizontal loading rates but higher vertical loading rates and larger peak knee flexion and extension moments (P < 0.05. Analysis of Interactions of Group x Shoe for maximum and mean vertical loading rates (P < 0.05 indicated that elite players exhibited lower left maximum and mean vertical loading rates in RHS compared to FHS (P < 0.01, while the intermediate group did not show any Shoe effect on vertical loading rates.These findings indicate that shoe heel curvature would play some role in altering ground reaction force impact during badminton lunge. The differences in impact loads and knee moments between elite and intermediate players may be useful in optimizing footwear design and training strategy to minimize the potential risks for impact related injuries in badminton.

Mid-term load forecasting of power systems by a new prediction method

International Nuclear Information System (INIS)

Amjady, Nima; Keynia, Farshid

2008-01-01

Mid-term load forecasting (MTLF) becomes an essential tool for today power systems, mainly in those countries whose power systems operate in a deregulated environment. Among different kinds of MTLF, this paper focuses on the prediction of daily peak load for one month ahead. This kind of load forecast has many applications like maintenance scheduling, mid-term hydro thermal coordination, adequacy assessment, management of limited energy units, negotiation of forward contracts, and development of cost efficient fuel purchasing strategies. However, daily peak load is a nonlinear, volatile, and nonstationary signal. Besides, lack of sufficient data usually further complicates this problem. The paper proposes a new methodology to solve it, composed of an efficient data model, preforecast mechanism and combination of neural network and evolutionary algorithm as the hybrid forecast technique. The proposed methodology is examined on the EUropean Network on Intelligent TEchnologies (EUNITE) test data and Iran's power system. We will also compare our strategy with the other MTLF methods revealing its capability to solve this load forecast problem

Impact Analysis of Reinforced Concrete Columns with Side Openings Subjected to Eccentric Axial Loads

Directory of Open Access Journals (Sweden)

Nazar Kamil Ali

2015-02-01

Full Text Available In this research the behavior of reinforced concrete columns with large side openings under impact loads was studied. The overall cross sectional dimensions of the column specimens used in this research were (500*1400 mm with total height of (14000 mm. The dimensions of side openings were (600*2000 mm. The column was reinforced with (20 mm diameter in longitudinal direction, while (12 mm ties were used in the transverse direction. The effect of eccentric impact loads on the horizontal and vertical displacement for this column was studied. Nonlinear finite element analysis has been carried out using ready computer finite element package (ANSYS to simulate the behavior of the reinforced concrete column with large side openings. Two load cases were considered in this investigation (C1, C2 with three different load values for each case. In the first case (C1 the loads was applied to one side of the column and in the second case (C2 the loads was applied to both sides. An Equilateral triangular load-time function was used for simulation the impact load results from gantry cranes supported by the column with total time duration (0.1 sec. In order to verify the analysis method, as no experimental data exist for comparing the obtained results, another analysis is made for tested conventional column under impact load at mid-height and good agreement has been obtained. For the above mentioned column, the maximum displacements were (33.3, 22.2 mm in the horizontal and longitudinal direction respectively, location of the maximum horizontal displacement was at the crown of the column. By comparing the results of the first loading case with the second one it is shown that in the horizontal direction, maximum displacement increases by (139%, (208%, and (147% respectively, also the maximum vertical displacement increases by (150%, (172%, and (172% respectively.

A methodology for Electric Power Load Forecasting

Directory of Open Access Journals (Sweden)

Eisa Almeshaiei

2011-06-01

Full Text Available Electricity demand forecasting is a central and integral process for planning periodical operations and facility expansion in the electricity sector. Demand pattern is almost very complex due to the deregulation of energy markets. Therefore, finding an appropriate forecasting model for a specific electricity network is not an easy task. Although many forecasting methods were developed, none can be generalized for all demand patterns. Therefore, this paper presents a pragmatic methodology that can be used as a guide to construct Electric Power Load Forecasting models. This methodology is mainly based on decomposition and segmentation of the load time series. Several statistical analyses are involved to study the load features and forecasting precision such as moving average and probability plots of load noise. Real daily load data from Kuwaiti electric network are used as a case study. Some results are reported to guide forecasting future needs of this network.

A Simplified Short Term Load Forecasting Method Based on Sequential Patterns

DEFF Research Database (Denmark)

Kouzelis, Konstantinos; Bak-Jensen, Birgitte; Mahat, Pukar

2014-01-01

Load forecasting is an essential part of a power system both for planning and daily operation purposes. As far as the latter is concerned, short term load forecasting has been broadly used at the transmission level. However, recent technological advancements and legislation have facilitated the i...... in comparison with an ARIMA model....

Protective containment behaviour under exceeded design loads

International Nuclear Information System (INIS)

Holub, I.; Stepan, J.; Maly, J.; Schererova, K.

2003-01-01

The contribution describes the calculation results of the behaviour of containment structure if loaded in excess of its design load. The Temelin NPP comprises two WWER 1000 blocks and containment consists of a pre-stressed reinforced concrete structure with a system of unbonded cables. The objective of the calculations was to determine the level of load caused by the internal pressure and temperature at which the containment protective function would fail. In the first step, the maximum overpressure was determined, which may be transferred by the containment structure. In further steps analyses were made of various combinations of simultaneous pressure and temperature loads. The contribution presents relevant calculation results, including the evaluation of containment structure behaviour including liner under loads that exceed its design parameters. (author)

Effect of regulated deficit irrigation and crop load on the antioxidant compounds of peaches.

Science.gov (United States)

Buendía, Begoña; Allende, Ana; Nicolás, Emilio; Alarcón, Juan J; Gil, Maria I

2008-05-28

The use of regulated deficit irrigation (RDI) strategies is becoming a common practice in areas with low water availability. Little information is available about the effects of RDI on the antioxidant content of fruits. In this study, the influence of RDI on the content of vitamin C, phenolic compounds and carotenoids was investigated. Two irrigation strategies, fully irrigated (FI) and RDI, were compared at two levels of thinning, commercial and half of the commercial crop load. RDI strategies affected the content of vitamin C, phenolics and carotenoids of Flordastar peaches. RDI caused fruit peel stress lowering the content of vitamin C and carotenoids, while increasing the phenolic content, mainly anthocyanins and procyanidins. Fruit weight was the only quality index influenced by the crop load as it increased in FI fruits at low crop load. In general, fruits from commercial crop load had slightly higher content of antioxidants to fruits from low crop load, although these influences were only observed in the peel. Additionally, the influence of irrigation controlled by two sensors related to plant water level, maximum daily trunk shrinkage (MDS) and sap flow (SF) on the antioxidant constituents of peaches was evaluated. The response of the fruits to SF sensor was similar to that observed for RDI strategy. According to the tested water sensors, SF did not act as a good plant-based water indicator for use in irrigation scheduling, as it caused an increase in the content of phenolics, similar to that observed for fruits subjected to RDI. Therefore, selection of RDI strategies and plant water indicators should be taken into account as they affect the content of antioxidants of peaches.

Simulation of Daily Weather Data Using Theoretical Probability Distributions.

Science.gov (United States)

Bruhn, J. A.; Fry, W. E.; Fick, G. W.

1980-09-01

A computer simulation model was constructed to supply daily weather data to a plant disease management model for potato late blight. In the weather model Monte Carlo techniques were employed to generate daily values of precipitation, maximum temperature, minimum temperature, minimum relative humidity and total solar radiation. Each weather variable is described by a known theoretical probability distribution but the values of the parameters describing each distribution are dependent on the occurrence of rainfall. Precipitation occurrence is described by a first-order Markov chain. The amount of rain, given that rain has occurred, is described by a gamma probability distribution. Maximum and minimum temperature are simulated with a trivariate normal probability distribution involving maximum temperature on the previous day, maximum temperature on the current day and minimum temperature on the current day. Parameter values for this distribution are dependent on the occurrence of rain on the previous day. Both minimum relative humidity and total solar radiation are assumed to be normally distributed. The values of the parameters describing the distribution of minimum relative humidity is dependent on rainfall occurrence on the previous day and current day. Parameter values for total solar radiation are dependent on the occurrence of rain on the current day. The assumptions made during model construction were found to be appropriate for actual weather data from Geneva, New York. The performance of the weather model was evaluated by comparing the cumulative frequency distributions of simulated weather data with the distributions of actual weather data from Geneva, New York and Fort Collins, Colorado. For each location, simulated weather data were similar to actual weather data in terms of mean response, variability and autocorrelation. The possible applications of this model when used with models of other components of the agro-ecosystem are discussed.

Fatigue History and in-situ Loading Studies of the overload Effect Using High Resolution X-ray Strain Profiling

International Nuclear Information System (INIS)

Croft, M.; Jisrawi, N.; Zhong, Z.; Holtz, R.; Sadananda, K.; Skaritka, J.; Tsakalakos, T.

2007-01-01

High-energy synchrotron X-ray diffraction experiments are used to perform local crack plane strain profiling of 4140 steel compact tension specimens fatigued at constant amplitude, subjected to a single overload cycle, then fatigued some more at constant amplitude. X-ray strain profiling results on a series of samples employing in-situ load cycling are correlated with the crack growth rate (da/dN) providing insight into the da/dN retardation known as the 'overload effect'. Immediately after the overload, the strain under maximum load is greatly reduced but the range of strain, between zero and maximum load, remains unchanged compared to the pre-overload values. At the point of maximum retardation, it is the strain range that is greatly reduced while the maximum-load strain has begun to recover to the pre-overload value. For a sample that has recovered to approximately half of the original da/dN value following the overload, the strain at maximum load is fully recovered while the strain range, though partially recovered, is still substantially reduced. The dominance of the strain range in the overload effect is clearly indicated. Subject to some assumptions, strong quantitative support for a crack growth rate driving force of the suggested form [(K max ) -p (ΔK) p ] γ is found. A dramatic nonlinear load dependence in the spatial distribution of the strain at maximum retardation is also demonstrated: at low load the response is dominantly at the overload position; whereas at high loads it is dominantly at the crack tip position. This transfer of load response away from the crack tip to the overload position appears fundamental to the overload effect for high R-ratio fatigue as studied here

Impact of measurement uncertainty from experimental load distribution factors on bridge load rating

Science.gov (United States)

Gangone, Michael V.; Whelan, Matthew J.

2018-03-01

Load rating and testing of highway bridges is important in determining the capacity of the structure. Experimental load rating utilizes strain transducers placed at critical locations of the superstructure to measure normal strains. These strains are then used in computing diagnostic performance measures (neutral axis of bending, load distribution factor) and ultimately a load rating. However, it has been shown that experimentally obtained strain measurements contain uncertainties associated with the accuracy and precision of the sensor and sensing system. These uncertainties propagate through to the diagnostic indicators that in turn transmit into the load rating calculation. This paper will analyze the effect that measurement uncertainties have on the experimental load rating results of a 3 span multi-girder/stringer steel and concrete bridge. The focus of this paper will be limited to the uncertainty associated with the experimental distribution factor estimate. For the testing discussed, strain readings were gathered at the midspan of each span of both exterior girders and the center girder. Test vehicles of known weight were positioned at specified locations on each span to generate maximum strain response for each of the five girders. The strain uncertainties were used in conjunction with a propagation formula developed by the authors to determine the standard uncertainty in the distribution factor estimates. This distribution factor uncertainty is then introduced into the load rating computation to determine the possible range of the load rating. The results show the importance of understanding measurement uncertainty in experimental load testing.

Increasing the maximum daily operation time of MNSR reactor by modifying its cooling system

International Nuclear Information System (INIS)

Khamis, I.; Hainoun, A.; Al Halbi, W.; Al Isa, S.

2006-08-01

thermal-hydraulic natural convection correlations have been formulated based on a thorough analysis and modeling of the MNSR reactor. The model considers detailed description of the thermal and hydraulic aspects of cooling in the core and vessel. In addition, determination of pressure drop was made through an elaborate balancing of the overall pressure drop in the core against the sum of all individual channel pressure drops employing an iterative scheme. Using this model, an accurate estimation of various timely core-averaged hydraulic parameters such as generated power, hydraulic diameters, flow cross area, ... etc. for each one of the ten-fuel circles in the core can be made. Furthermore, distribution of coolant and fuel temperatures, including maximum fuel temperature and its location in the core, can now be determined. Correlation among core-coolant average temperature, reactor power, and core-coolant inlet temperature, during both steady and transient cases, have been established and verified against experimental data. Simulating various operating condition of MNSR, good agreement is obtained for at different power levels. Various schemes of cooling have been investigated for the purpose of assessing potential benefits on the operational characteristics of the syrian MNSR reactor. A detailed thermal hydraulic model for the analysis of MNSR has been developed. The analysis shows that an auxiliary cooling system, for the reactor vessel or installed in the pool which surrounds the lower section of the reactor vessel, will significantly offset the consumption of excess reactivity due to the negative reactivity temperature coefficient. Hence, the maximum operating time of the reactor is extended. The model considers detailed description of the thermal and hydraulic aspects of cooling the core and its surrounding vessel. Natural convection correlations have been formulated based on a thorough analysis and modeling of the MNSR reactor. The suggested 'micro model

United States Historical Climatology Network Daily Temperature and Precipitation Data (1871-1997)

Energy Technology Data Exchange (ETDEWEB)

Easterling, D.R.

2002-10-28

This document describes a database containing daily observations of maximum and minimum temperature, precipitation amount, snowfall amount, and snow depth from 1062 observing stations across the contiguous US. This database is an expansion and update of the original 138-station database previously released by the Carbon Dioxide Information Analysis Center (CDIAC) as CDIAC numeric data package NDP-042. These 1062 stations are a subset of the 1221-station US Historical Climatology Network (HCN), a monthly database compiled by the National Climatic Data Center (Asheville, North Carolina) that has been widely used in analyzing US climate. Data from 1050 of these daily records extend into the 1990s, while 990 of these extend through 1997. Most station records are essentially complete for at least 40 years; the latest beginning year of record is 1948. Records from 158 stations begin prior to 1900, with that of Charleston, South Carolina beginning the earliest (1871). The daily resolution of these data makes them extremely valuable for studies attempting to detect and monitor long-term climatic changes on a regional scale. Studies using daily data may be able to detect changes in regional climate that would not be apparent from analysis of monthly temperature and precipitation data. Such studies may include analyses of trends in maximum and minimum temperatures, temperature extremes, daily temperature range, precipitation ''event size'' frequency, and the magnitude and duration of wet and dry periods. The data are also valuable in areas such as regional climate model validation and climate change impact assessment. This database is available free of charge from CDIAC as a numeric data package (NDP).

Generating daily weather data for ecosystem modelling in the Congo River Basin

Science.gov (United States)

Petritsch, Richard; Pietsch, Stephan A.

2010-05-01

Daily weather data are an important constraint for diverse applications in ecosystem research. In particular, temperature and precipitation are the main drivers for forest ecosystem productivity. Mechanistic modelling theory heavily relies on daily values for minimum and maximum temperatures, precipitation, incident solar radiation and vapour pressure deficit. Although the number of climate measurement stations increased during the last centuries, there are still regions with limited climate data. For example, in the WMO database there are only 16 stations located in Gabon with daily weather measurements. Additionally, the available time series are heavily affected by measurement errors or missing values. In the WMO record for Gabon, on average every second day is missing. Monthly means are more robust and may be estimated over larger areas. Therefore, a good alternative is to interpolate monthly mean values using a sparse network of measurement stations, and based on these monthly data generate daily weather data with defined characteristics. The weather generator MarkSim was developed to produce climatological time series for crop modelling in the tropics. It provides daily values for maximum and minimum temperature, precipitation and solar radiation. The monthly means can either be derived from the internal climate surfaces or prescribed as additional inputs. We compared the generated outputs observations from three climate stations in Gabon (Lastourville, Moanda and Mouilla) and found that maximum temperature and solar radiation were heavily overestimated during the long dry season. This is due to the internal dependency of the solar radiation estimates to precipitation. With no precipitation a cloudless sky is assumed and thus high incident solar radiation and a large diurnal temperature range. However, in reality it is cloudy in the Congo River Basin during the long dry season. Therefore, we applied a correction factor to solar radiation and temperature range

LOAD THAT MAXIMIZES POWER OUTPUT IN COUNTERMOVEMENT JUMP

Directory of Open Access Journals (Sweden)

Pedro Jimenez-Reyes

2016-02-01

Full Text Available ABSTRACT Introduction: One of the main problems faced by strength and conditioning coaches is the issue of how to objectively quantify and monitor the actual training load undertaken by athletes in order to maximize performance. It is well known that performance of explosive sports activities is largely determined by mechanical power. Objective: This study analysed the height at which maximal power output is generated and the corresponding load with which is achieved in a group of male-trained track and field athletes in the test of countermovement jump (CMJ with extra loads (CMJEL. Methods: Fifty national level male athletes in sprinting and jumping performed a CMJ test with increasing loads up to a height of 16 cm. The relative load that maximized the mechanical power output (Pmax was determined using a force platform and lineal encoder synchronization and estimating the power by peak power, average power and flight time in CMJ. Results: The load at which the power output no longer existed was at a height of 19.9 ± 2.35, referring to a 99.1 ± 1% of the maximum power output. The load that maximizes power output in all cases has been the load with which an athlete jump a height of approximately 20 cm. Conclusion: These results highlight the importance of considering the height achieved in CMJ with extra load instead of power because maximum power is always attained with the same height. We advise for the preferential use of the height achieved in CMJEL test, since it seems to be a valid indicative of an individual's actual neuromuscular potential providing a valid information for coaches and trainers when assessing the performance status of our athletes and to quantify and monitor training loads, measuring only the height of the jump in the exercise of CMJEL.

Estimating wheat and maize daily evapotranspiration using artificial neural network

Science.gov (United States)

Abrishami, Nazanin; Sepaskhah, Ali Reza; Shahrokhnia, Mohammad Hossein

2018-02-01

In this research, artificial neural network (ANN) is used for estimating wheat and maize daily standard evapotranspiration. Ten ANN models with different structures were designed for each crop. Daily climatic data [maximum temperature (T max), minimum temperature (T min), average temperature (T ave), maximum relative humidity (RHmax), minimum relative humidity (RHmin), average relative humidity (RHave), wind speed (U 2), sunshine hours (n), net radiation (Rn)], leaf area index (LAI), and plant height (h) were used as inputs. For five structures of ten, the evapotranspiration (ETC) values calculated by ETC = ET0 × K C equation (ET0 from Penman-Monteith equation and K C from FAO-56, ANNC) were used as outputs, and for the other five structures, the ETC values measured by weighing lysimeter (ANNM) were used as outputs. In all structures, a feed forward multiple-layer network with one or two hidden layers and sigmoid transfer function and BR or LM training algorithm was used. Favorite network was selected based on various statistical criteria. The results showed the suitable capability and acceptable accuracy of ANNs, particularly those having two hidden layers in their structure in estimating the daily evapotranspiration. Best model for estimation of maize daily evapotranspiration is «M»ANN1 C (8-4-2-1), with T max, T min, RHmax, RHmin, U 2, n, LAI, and h as input data and LM training rule and its statistical parameters (NRMSE, d, and R2) are 0.178, 0.980, and 0.982, respectively. Best model for estimation of wheat daily evapotranspiration is «W»ANN5 C (5-2-3-1), with T max, T min, Rn, LAI, and h as input data and LM training rule, its statistical parameters (NRMSE, d, and R 2) are 0.108, 0.987, and 0.981 respectively. In addition, if the calculated ETC used as the output of the network for both wheat and maize, higher accurate estimation was obtained. Therefore, ANN is suitable method for estimating evapotranspiration of wheat and maize.

Determining Maximum Photovoltaic Penetration in a Distribution Grid considering Grid Operation Limits

DEFF Research Database (Denmark)

Kordheili, Reza Ahmadi; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna

2014-01-01

High penetration of photovoltaic panels in distribution grid can bring the grid to its operation limits. The main focus of the paper is to determine maximum photovoltaic penetration level in the grid. Three main criteria were investigated for determining maximum penetration level of PV panels...... for this grid: even distribution of PV panels, aggregation of panels at the beginning of each feeder, and aggregation of panels at the end of each feeder. Load modeling is done using Velander formula. Since PV generation is highest in the summer due to irradiation, a summer day was chosen to determine maximum......; maximum voltage deviation of customers, cables current limits, and transformer nominal value. Voltage deviation of different buses was investigated for different penetration levels. The proposed model was simulated on a Danish distribution grid. Three different PV location scenarios were investigated...

Optimum design of laminated composite under axial compressive load

Indian Academy of Sciences (India)

In the present study optimal design of composite laminates, with and without rectangular cut-out, is carried out for maximizing the buckling load. Optimization study is carried out for obtaining the maximum buckling load with design variables as ply thickness, cut-out size and orientation of cut-out with respect to laminate.

Effect of Load Duration on Timber Structures in Denmark

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Stang, Birgitte Friis Dela; Svensson, Staffan

2003-01-01

. The parameters in these models are fitted by the Maximum Likelihood Method using data relevant for Danish structural timber and the statistical uncertainty is quantified. The reliability is evaluated using representative shortand long-term limit states, and the load duration factor kmod is estimated using......Load duration effects are estimated on basis of simulation of realizations of wind, snow and imposed loads in accordance with the load models in the Danish structural codes. Three damage accumulation models are considered, namely Gerhards model, Barret & Foschi's model and Foschi & Yao's model...

Optimal Velocity to Achieve Maximum Power Output – Bench Press for Trained Footballers

OpenAIRE

Richard Billich; Jakub Štvrtňa; Karel Jelen

2015-01-01

Optimal Velocity to Achieve Maximum Power Output – Bench Press for Trained Footballers In today’s world of strength training there are many myths surrounding effective exercising with the least possible negative effect on one’s health. In this experiment we focus on the finding of a relationship between maximum output, used load and the velocity with which the exercise is performed. The main objective is to find the optimal speed of the exercise motion which would allow us to reach the ma...

Load-following performance and assessment of CANDU fuel

Energy Technology Data Exchange (ETDEWEB)

Tayal, M.; Floyd, M.; Rattan, D.; Xu, Z.; Manzer, A.; Lau, J. [Atomic Energy of Canada Limited, Mississauga, Ontario (Canada); Kohn, E. [Ontario Power Generation, Fuel and Fuel Channel Analysis Dept., Toronto, Ontario (Canada)

1999-09-01

Load following of nuclear reactors is now becoming an economic necessity in some countries. When nuclear power stations are operated in a load-following mode, the reactor and the fuel may be subjected to step changes in power on a weekly, daily, or even hourly basis, depending on the grid's needs. This paper updates the previous surveys of load-following capability of CANDU fuel, focusing mainly on the successful experience at the Bruce B station. As well, initial analytical assessments are provided that illustrate the capability of CANDU fuel to survive conditions other than those for which direct in-reactor evidence is available. (author)

The effects of self-report cognitive failures and cognitive load on antisaccade performance

Directory of Open Access Journals (Sweden)

Nick eBerggren

2011-10-01

Full Text Available Individuals reporting high levels of distractibility in everyday life show impaired performance in standard laboratory tasks measuring selective attention and inhibitory processes. Similarly, increasing cognitive load leads to more errors/distraction in a variety of cognitive tasks. How these two factors interact is currently unclear; highly distractible individuals may be affected more when their cognitive resources are taxed, or load may linearly affect performance for all individuals. We investigated the relationship between self-reported levels of cognitive failuresin daily life and performance in the antisaccade task, a widely used tool examining attentional control. Levels of concurrent cognitive demand were manipulated using a secondary auditory discrimination task. We found that both levels of self-reported cognitive failures and task load increased antisaccade latencies while having no effect on prosaccade eye-movements. However individuals rating themselves as suffering few daily life distractions showed a comparable load cost to those who experience many. These findings suggest that the likelihood of distraction is governed by the addition of both internal susceptibility and the external current load placed on working memory.

Daily torpor and hibernation in birds and mammals

Science.gov (United States)

RUF, THOMAS; GEISER, FRITZ

2014-01-01

Many birds and mammals drastically reduce their energy expenditure during times of cold exposure, food shortage, or drought, by temporarily abandoning euthermia, i.e., the maintenance of high body temperatures. Traditionally, two different types of heterothermy, i.e., hypometabolic states associated with low body temperatures (torpor), have been distinguished: Daily torpor, which lasts less than 24 h and is accompanied by continued foraging, versus hibernation, with torpor bouts lasting consecutive days to several weeks in animals that usually do not forage but rely on energy stores, either food caches or body energy reserves. This classification of torpor types has been challenged however, suggesting that these phenotypes may merely represent the extremes in a continuum of traits. Here, we investigate whether variables of torpor in 214 species, 43 birds and 171 mammals form a continuum or a bimodal distribution. We use Gaussian-mixture cluster analysis as well as phylogenetically informed regressions to quantitatively assess the distinction between hibernation and daily torpor and to evaluate the impact of body mass and geographical distribution of species on torpor traits. Cluster analysis clearly confirmed the classical distinction between daily torpor and hibernation. Overall, heterothermic endotherms are small on average, but hibernators are significantly heavier than daily heterotherms and also are distributed at higher average latitudes (~35°) than daily heterotherms (~25°). Variables of torpor for an average 30-g heterotherm differed significantly between daily heterotherms and hibernators. Average maximum torpor bout duration was >30-fold longer, and mean torpor bout duration >25-fold longer in hibernators. Mean minimum body temperature differed by ~13°C, and the mean minimum torpor metabolic rate was ~35% of the BMR in daily heterotherms but only 6% of basal metabolic rate in hibernators. Consequently, our analysis strongly supports the view that

Comparison between simplified load spectra in accordance with Germanische Lloyd guidelines, and load spectra derived from time domain simulations

Energy Technology Data Exchange (ETDEWEB)

Rees, M [Aerodyn Energiesysteme gmbH, Rendsburg (Germany)

1996-09-01

The Germanische Lloyd guideline allows calculations of load spectra in two fundamentally different ways. In the case of the so-called `simplified load spectra` the maximum amplitude of fluctuation of a load component is formed as {+-}75% of the average value of the purely aerodynamic loads of this component at rated wind conditions, together with an overlay of mass-related loads. The second method allowed in the GL guideline is the calculation of load spectra from simulation results in the time domain. For a number of average wind speeds the time-dependent characteristics of the load components are calculated taking account of the natural spatial turbulence of the wind. These are converted into load spectra using the rainflow method. In a parametric study the load spectra are calculated according to both methods and compared. The calculations are performed for turbines with rated powers of 100 kW to 2000 kW, with two and three blades, and also for stall-controlled and pitch-controlled turbines. The calculated load spectra are compared with each by means of 1 P fatigue equivalent load spectra. The influence of individual parameters is presented, as is the validity of the simplified load spectra. (au)

Bioavailability of oxycodone after administration of a new prolonged-release once-daily tablet formulation in healthy subjects, in comparison to an established twice-daily tablet
.

Science.gov (United States)

Scheidel, Bernhard; Maritz, Martina A; Gschwind, Yves J; Steigerwald, Kerstin; Guth, Volker; Kovacs, Peter; Rey, Helene

2017-11-01

To evaluate and to compare the bioavailability, the influence of food intake on the bioavailability, and the safety and tolerability of a newly-developed oxycodone once-daily (OOD) prolonged-release tablet with an established oxycodone twice-daily (OTD) prolonged-release tablet after single-dose administration under fasting or fed conditions as well as after multiple-dose administration. Three single-center, open-label, randomized, balanced, two-treatment, two-period, two-sequence crossover studies were conducted. In each study, 36 healthy volunteers were randomized to receive 10 mg oxycodone daily as OOD (oxycodone HCL 10-mg PR tablets XL (Develco Pharma Schweiz AG, Pratteln, Switzerland); administration of 1 tablet in the morning) or as OTD (reference formulation: oxygesic 5-mg tablets (Mundipharma GmbH, Limburg an der Lahn, Germany); administration of 1 tablet in the morning and 1 tablet in the evening). Tablets were administered once daily or twice daily under fasting conditions (study 1) or under fed conditions (study 2) as well as after multiple-dose administration (study 3). A sufficient number of blood samples were taken for describing plasma profiles and for calculation of pharmacokinetic parameters. Plasma concentrations of oxycodone were determined by LC-MS/MS. Safety and tolerability were monitored and assessed in all three studies. Plasma profiles of OOD reveal sustained concentrations of oxycodone over the complete dosing interval of 24 hours. In comparison to the OTD reference formulation, the OOD test formulation showed a slightly slower increase of concentrations within the absorption phase and similar plasma concentrations at the maximum and at the end of the dosing interval (24 hours). Extent of bioavailability (AUC), maximum plasma concentrations (Cmax), and plasma concentrations at the end of the dosing interval (Cτ,ss,24h) of OOD could be classified as comparable to OTD considering 90% confidence intervals (CIs) and acceptance limits of 80

Experimental study on the wave loads on a rotor of the WEPTOS Wave Energy Converter

DEFF Research Database (Denmark)

Pecher, Arthur; Kofoed, Jens Peter

Experimental tests have been performed to investigate the wave load on the rotor in design wave conditions. These wave loads should give an indication of the required structural strength around the rotors as well as for other equipment such as the bearings. During the lab tests, the wave loads have...... been measured for the following configurations: • Head and beam seas (wave coming from the front and the side) • For three different submergence levels • For three different dispositions of the rotor (free to rotate, and fixed at 50° and 90°) Based on this results, an estimation of the maximum wave...... loads has been made on the maximum wave loads at the DanWEC test site....

Soil mechanical stresses in high wheel load agricultural field traffic: a case study

DEFF Research Database (Denmark)

Lamandé, Mathieu; Schjønning, Per

2017-01-01

highly skewed. Across tyres, the maximum stress in the contact area correlated linearly with, but was much higher than, the mean ground pressure. For each of the three soil depths, the maximum stresses under the tyres were significantly correlated with the wheel load, but not with other loading......Subsoil compaction is a serious long-term threat to soil functions. Only a few studies have quantified the mechanical stresses reaching deep subsoil layers for modern high wheel load machinery. In the present study we measured the vertical stresses in the tyre–soil contact area and at 0.3, 0...

Analyzing temporal changes in maximum runoff volume series of the Danube River

International Nuclear Information System (INIS)

Halmova, Dana; Pekarova, Pavla; Onderka, Milan; Pekar, Jan

2008-01-01

Several hypotheses claim that more extremes in climatic and hydrologic phenomena are anticipated. In order to verify such hypotheses it is inevitable to examine the past periods by thoroughly analyzing historical data. In the present study, the annual maximum runoff volumes with t-day durations were calculated for a 130-year series of mean daily discharge of Danube River at Bratislava gauge (Slovakia). Statistical methods were used to clarify how the maximum runoff volumes of the Danube River changed over two historical periods (1876-1940 and 1941-2005). The conclusion is that the runoff volume regime during floods has not changed significantly during the last 130 years.

Experimental Testing of Monopiles in Sand Subjected to One-Way Long-Term Cyclic Lateral Loading

DEFF Research Database (Denmark)

Roesen, Hanne Ravn; Ibsen, Lars Bo; Andersen, Lars Vabbersgaard

2013-01-01

In the offshore wind turbine industry the most widely used foundation type is the monopile. Due to the wave and wind forces the monopile is subjected to a strong cyclic loading with varying amplitude, maximum loading level, and varying loading period. In this paper the soil–pile interaction...... of a monopile in sand subjected to a long-term cyclic lateral loading is investigated by means of small scale tests. The tests are conducted with a mechanical loading rig capable of applying the cyclic loading as a sine signal with varying amplitude, mean loading level, and loading period for more than 60 000...... cycles. The tests are conducted in dense saturated sand. The maximum moment applied in the cyclic tests is varied from 18% to 36% of the ultimate lateral resistance found in a static loading test. The tests reveal that the accumulated rotation can be expressed by use of a power function. Further, static...

Identifying critical constraints for the maximum loadability of electric power systems - analysis via interior point method

Energy Technology Data Exchange (ETDEWEB)

Barboza, Luciano Vitoria [Sul-riograndense Federal Institute for Education, Science and Technology (IFSul), Pelotas, RS (Brazil)], E-mail: luciano@pelotas.ifsul.edu.br

2009-07-01

This paper presents an overview about the maximum load ability problem and aims to study the main factors that limit this load ability. Specifically this study focuses its attention on determining which electric system buses influence directly on the power demand supply. The proposed approach uses the conventional maximum load ability method modelled by an optimization problem. The solution of this model is performed using the Interior Point methodology. As consequence of this solution method, the Lagrange multipliers are used as parameters that identify the probable 'bottlenecks' in the electric power system. The study also shows the relationship between the Lagrange multipliers and the cost function in the Interior Point optimization interpreted like sensitivity parameters. In order to illustrate the proposed methodology, the approach was applied to an IEEE test system and to assess its performance, a real equivalent electric system from the South- Southeast region of Brazil was simulated. (author)

Ice load reducer for dams : laboratory tests

Energy Technology Data Exchange (ETDEWEB)

Lupien, R.; Cote, A.; Robert, A. [Institut de Recherche d' Hydro-Quebec, Varennes, PQ (Canada)

2009-07-01

Many studies have focused on measuring static ice loads on various hydraulic structures in Canada. This paper discussed a Hydro-Quebec research project whose main purpose was to harmonize the ice thrust value in load combinations for use in general hydraulic works or for specific cases. The objectives of the project were to obtain a better understanding of existing data and to characterize sites and their influence on ice thrust; study the structural mechanisms involved in the generation of ice thrust, their consequences on the structural behaviour of ice and the natural mitigating circumstances that may be offered by ice properties or site operating procedures; and examine the relevance of developing an ice load reducer for works that might not fit the harmonized design value. The paper presented the main research goals and ice load reducer goals, with particular focus on the four pipe samples that were planned, built and tested. The experimental program involved checking the pipe shape behaviour in terms of flexibility-stiffness; maximum deformations; maximum load reduction; permanent deformations; and, ability to shape recovering. The testing also involved examining the strength versus strain rate; creep versus strain rate; and creep capacity under biaxial state of tension and compression. It was concluded that the two phenomena involved in generation of ice thrust, notably thermal expansion and water level changes, had very low strain rates. 8 refs., 2 tabs., 16 figs.

Comparison of Water-Load Distributions Obtained during Seaplane Landings with Bureau of Aeronautics Specifications. TED No. NACA 2413

Science.gov (United States)

Smiley, Robert F.; Haines, Gilbert A.

1949-01-01

Bureau of Aeronautics Design Specifications SS-IC-2 for water loads in sheltered water are compared with experimental water loads obtained during a full--scale landing investigation. This investigation was conducted with a JRS-1 flying boat which has a 20 degrees dead-rise V-bottom with a partial chine flare. The range of landing conditions included airspeeds between 88 and 126 feet per second, sinking speeds between 1.6 and 9.1 feet per second, flight angles less than 6 degrees, and trims between 2 degrees and 12 degrees. Landings were moderate and were made in calm water. Measurements were obtained of maximum over-all loads, maximum pitching moments, and pressure distributions. Maximum experimental loads include over-all load factors of 2g, moments of 128,000 pound-feet, and maximum local pressures greater than 40 pounds per square inch. Experimental over-all loads are approximately one-half the design values, while local pressures are of the same order as or larger than pressures calculated from specifications for plating, stringer, floor, and frame design. The value of this comparison is limited, to some extent, by the moderate conditions of the test and by the necessary simplifying assumptions used in comparing the specifications with the experimental loads.

Maximum daily rainfall in South Korea

Indian Academy of Sciences (India)

and Dongseok Choi. 2. 1. School of Mathematics, University of Manchester, Manchester M60 1QD, UK. ... This paper provides the first application of extreme value distributions to rainfall data from South Korea. 1. ..... protection. This paper only ...

In vivo facet joint loading of the canine lumbar spine.

Science.gov (United States)

Buttermann, G R; Schendel, M J; Kahmann, R D; Lewis, J L; Bradford, D S

1992-01-01

This study describes a technique to measure in vivo loads and the resultant load-contact locations in the facet joint of the canine lumbar spine. The technique is a modification of a previously described in vitro method that used calibrated surface strains of the lateral aspect of the right L3 cranial articular process. In the present study, strains were measured during various in vivo static and dynamic activities 3 days after strain gage implantation. The in vivo recording technique and its errors, which depend on the location of the applied facet loads, is described. The results of applying the technique to five dogs gave the following results. Relative resultant contact load locations on the facet tended to be in the central and caudal portion of the facet in extension activities, central and cranial in standing, and cranial and ventral in flexion or right-turning activities. Right-turning contact locations were ventral and cranial to left-turning locations. Resultant load locations at peak loading during walking were in the central region of the facet, whereas resultant load locations at minimum loading during walking were relatively craniad. This resultant load-contact location during a walk gait cycle typically migrated in an arc with a displacement of 4 mm from minimum to maximum loading. Static tests resulted in a range of facet loads of 0 N in flexion and lying to 185 N for two-legged standing erect, and stand resulted in facet loads of 26 +/- 15 N (mean +/- standard deviation [SD]). Dynamic tests resulted in peak facet loads ranging from 55 N while walking erect to 170 N for climbing up stairs. Maximum walk facet loads were 107 +/- 27 N. The technique is applicable to in vivo studies of a canine facet joint osteoarthritis model and may be useful for establishing an understanding of the biomechanics of low-back pain.

Lifetime and residual strength of wood subjected to static and variable load

DEFF Research Database (Denmark)

Nielsen, Lauge Fuglsang

1997-01-01

of load amplitude, load average, fractional time under maximum load, and load frequency. The analysis includes prediction of residual strength (re-cycle strength) during the process of load cycling. It is concluded that number of cycles to failure is a very poor design criterion. The theory......).It is demonstrated how the theory developed can be generalised also to consider non-harmonic load variations. An algorithm is presented for this purpose which might be suggested as a qualified alternative to the Palmgren-Miner’s method normally used in fatigue analysis of materials under arbitrary load variations...

Population pharmacokinetics and maximum a posteriori probability Bayesian estimator of abacavir: application of individualized therapy in HIV-infected infants and toddlers.

NARCIS (Netherlands)

Zhao, W.; Cella, M.; Pasqua, O. Della; Burger, D.M.; Jacqz-Aigrain, E.

2012-01-01

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: Abacavir is used to treat HIV infection in both adults and children. The recommended paediatric dose is 8 mg kg(-1) twice daily up to a maximum of 300 mg twice daily. Weight was identified as the central covariate influencing pharmacokinetics of abacavir in

Prediction of wax buildup in 24 inch cold, deep sea oil loading line

Energy Technology Data Exchange (ETDEWEB)

Asperger, R.G.; Sattler, R.E.; Tolonen, W.J.; Pitchford, A.C.

1981-10-01

When designing pipelines for cold environments, it is important to know how to predict potential problems due to wax deposition on the pipeline's inner surface. The goal of this work was to determine the rate of wax buildup and the maximum, equlibrium wax thickness for a North Sea field loading line. The experimental techniques and results used to evaluate the waxing potential of the crude oil (B) are described. Also, the theoretic model which was used for predicting the maximum wax deposit thickness in the crude oil (B) loading pipeline at controlled temperatures of 40 F (4.4 C) and 100 F (38 C), is illustrated. Included is a recommendation of a procedure for using hot oil at the end of a tanker loading period in order to dewax the crude oil (B) line. This technique would give maximum heating of the pipeline and should be followed by shutting the hot oil into the pipeline at the end of the loading cycle which will provide a hot oil soaking to help soften existing wax. 14 references.

Accelerometer-measured daily physical activity related to aerobic fitness in children and adolescents

DEFF Research Database (Denmark)

Dencker, Magnus; Andersen, Lars Bo

2011-01-01

Maximum oxygen uptake ([Vdot]O(2PEAK)) is generally considered to be the best single marker for aerobic fitness. While a positive relationship between daily physical activity and aerobic fitness has been established in adults, the relationship appears less clear in children and adolescents...

Using the load-velocity relationship for 1RM prediction.

OpenAIRE

Jidovtseff, Boris; Harris, N. K.; Crielaard, Jean-Michel; Cronin, J. B.

2011-01-01

Jidovtseff, B, Harris, NK, Crielaard, J-M, and Cronin, JB. Using the load-velocity relationship for 1RM prediction. J Strength Cond Res 24(x): 000-000, 2009-The purpose of this study was to investigate the ability of the load-velocity relationship to accurately predict a bench press 1 repetition maximum (1RM). Data from 3 different bench press studies (n = 112) that incorporated both 1RM assessment and submaximal load-velocity profiling were analyzed. Individual regression analysis was perfor...

A pollutant load hierarchical allocation method integrated in an environmental capacity management system for Zhushan Bay, Taihu Lake.

Science.gov (United States)

Liang, Shidong; Jia, Haifeng; Yang, Cong; Melching, Charles; Yuan, Yongping

2015-11-15

An environmental capacity management (ECM) system was developed to help practically implement a Total Maximum Daily Load (TMDL) for a key bay in a highly eutrophic lake in China. The ECM system consists of a simulation platform for pollutant load calculation and a pollutant load hierarchical allocation (PLHA) system. The simulation platform was developed by linking the Environmental Fluid Dynamics Code (EFDC) and Water Quality Analysis Simulation Program (WASP). In the PLHA, pollutant loads were allocated top-down in several levels based on characteristics of the pollutant sources. Different allocation methods could be used for the different levels with the advantages of each method combined over the entire allocation. Zhushan Bay of Taihu Lake, one of the most eutrophic lakes in China, was selected as a case study. The allowable loads of total nitrogen, total phosphorus, ammonia, and chemical oxygen demand were found to be 2122.2, 94.9, 1230.4, and 5260.0 t·yr(-1), respectively. The PLHA for the case study consists of 5 levels. At level 0, loads are allocated to those from the lakeshore direct drainage, atmospheric deposition, internal release, and tributary inflows. At level 1 the loads allocated to tributary inflows are allocated to the 3 tributaries. At level 2, the loads allocated to one inflow tributary are allocated to upstream areas and local sources along the tributary. At level 3, the loads allocated to local sources are allocated to the point and non-point sources from different towns. At level 4, the loads allocated to non-point sources in each town are allocated to different villages. Compared with traditional forms of pollutant load allocation methods, PLHA can combine the advantages of different methods which put different priority weights on equity and efficiency, and the PLHA is easy to understand for stakeholders and more flexible to adjust when applied in practical cases. Copyright © 2015 Elsevier B.V. All rights reserved.

Design of Asymmetrical Relay Resonators for Maximum Efficiency of Wireless Power Transfer

Directory of Open Access Journals (Sweden)

Bo-Hee Choi

2016-01-01

Full Text Available This paper presents a new design method of asymmetrical relay resonators for maximum wireless power transfer. A new design method for relay resonators is demanded because maximum power transfer efficiency (PTE is not obtained at the resonant frequency of unit resonator. The maximum PTE for relay resonators is obtained at the different resonances of unit resonator. The optimum design of asymmetrical relay is conducted by both the optimum placement and the optimum capacitance of resonators. The optimum placement is found by scanning the positions of the relays and optimum capacitance can be found by using genetic algorithm (GA. The PTEs are enhanced when capacitance is optimally designed by GA according to the position of relays, respectively, and then maximum efficiency is obtained at the optimum placement of relays. The capacitance of the second resonator to nth resonator and the load resistance should be determined for maximum efficiency while the capacitance of the first resonator and the source resistance are obtained for the impedance matching. The simulated and measured results are in good agreement.

Global Historical Climatology Network - Daily (GHCN-Daily), Version 3

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Global Historical Climatology Network - Daily (GHCN-Daily) dataset integrates daily climate observations from approximately 30 different data sources. Version 3...

The Influence of Pressure Distribution on the Maximum Values of Stress in FEM Analysis of Plain Bearings

Directory of Open Access Journals (Sweden)

Vasile Cojocaru

2016-12-01

Full Text Available Several methods can be used in the FEM studies to apply the loads on a plain bearing. The paper presents a comparative analysis of maximum stress obtained for three loading scenarios: resultant force applied on the shaft – bearing assembly, variable pressure with sinusoidal distribution applied on the bearing surface, variable pressure with parabolic distribution applied on the bearing surface.

Evaluation of SMART load follow operation capability

International Nuclear Information System (INIS)

Song, Jae Seung; Zee, Sung Quun

1998-07-01

The daily load follow operation capability of SMART, which is 330 MWth integral reactor with boron free operation concept, was evaluated. In the boron free operation core the axial offset(AO) can not be limited or limited by wider range than the typical PWR that uses soluble boron. Current SMART conceptual core design does not have the limit for the axial offset and the operation is limited by three dimensional local power peak. In this report, the capability of load follow operation is evaluated for 14-2-6-2 daily load follow by 50% power reduction that is very typical in the large commercial power reactors. The cycle length of SMART is limited by three dimensional local power peak and the nominal axial power distribution is top skewed at the end of cycle. When the power returns to 100%, control rod should be withdrawn for the compensation of reactivity decrease due to the xenon buildup. The control rod withdrawal results in the increase of three dimensional local power peak. To solve this problem, an operation strategy for the control of local peak. To solve this problem, an operation strategy for the control of local peak was established and it was shown that the strategy is effective in controlling the local peak less than target value of the three dimensional local power peak. (author). 7 refs., 5 tabs., 13 figs

An implementation of particle swarm optimization to evaluate optimal under-voltage load shedding in competitive electricity markets

Science.gov (United States)

Hosseini-Bioki, M. M.; Rashidinejad, M.; Abdollahi, A.

2013-11-01

Load shedding is a crucial issue in power systems especially under restructured electricity environment. Market-driven load shedding in reregulated power systems associated with security as well as reliability is investigated in this paper. A technoeconomic multi-objective function is introduced to reveal an optimal load shedding scheme considering maximum social welfare. The proposed optimization problem includes maximum GENCOs and loads' profits as well as maximum loadability limit under normal and contingency conditions. Particle swarm optimization (PSO) as a heuristic optimization technique, is utilized to find an optimal load shedding scheme. In a market-driven structure, generators offer their bidding blocks while the dispatchable loads will bid their price-responsive demands. An independent system operator (ISO) derives a market clearing price (MCP) while rescheduling the amount of generating power in both pre-contingency and post-contingency conditions. The proposed methodology is developed on a 3-bus system and then is applied to a modified IEEE 30-bus test system. The obtained results show the effectiveness of the proposed methodology in implementing the optimal load shedding satisfying social welfare by maintaining voltage stability margin (VSM) through technoeconomic analyses.

Vibrations of composite circular shell structures due to transient loads

International Nuclear Information System (INIS)

Schrader, K.-H.; Krutzik, N.; Winkel, G.

1975-01-01

Referring to a container consisting of different shell structures - such as spherical, cylindrical and conical shells - the dynamic behavior of coupled spatial shell structures due to transient loads will be investigated. The spatial structure including the filling of water will be idealized as a three-dimensional model consisting of ring elements. The influence of the water filling on the vibrations will be considered by virtual masses added to the shell structures. In circular direction as well as in meridional direction a consistent mass model has been used. By variation of the virtual masses it will be clarified, how these additional masses influence the vibrational behavior of the composed system. Another aspect which will be investigated is the influence of different stiffnesses of substructures or parts of substructures on the natural frequencies, and on their affiliated eigensystems. Furthermore, the maximum and minimum stresses in the structures caused by transient loads acting on the inner surface of the shells will be explored. Here it seems to be possible to locate an area of maximum strain. Rotational loads as well as nonrotational loads will be considered

Reliability-Based Modeling of Moisture and Load-Duration Effects

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Svensson, Staffan

2005-01-01

Load duration effects with respect to reduction of load bearing capacity are very important for structural timber. This paper describes how the load duration effects combined with moisture content and variations c an be determined on basis of simulation of realizations of the time varying load...... and moisture processes. Permanent and snow load sand moisture variations are considered and stochastic models are formulated in accordance with the load models in the Danish structural codes. A damage accumulation model based on fracture mechanics that accounts for both load duration and moisture effects...... is derived. The parameters in the model are fitted to data relevant for Nordic structural timber using the Maximum Likelihood method. The probability of failure as function of time is estimated for representative limit states based on: a) short term strength and b) long term damage accumulation...

Estimating Daily Maximum and Minimum Land Air Surface Temperature Using MODIS Land Surface Temperature Data and Ground Truth Data in Northern Vietnam

Directory of Open Access Journals (Sweden)

Phan Thanh Noi

2016-12-01

Full Text Available This study aims to evaluate quantitatively the land surface temperature (LST derived from MODIS (Moderate Resolution Imaging Spectroradiometer MOD11A1 and MYD11A1 Collection 5 products for daily land air surface temperature (Ta estimation over a mountainous region in northern Vietnam. The main objective is to estimate maximum and minimum Ta (Ta-max and Ta-min using both TERRA and AQUA MODIS LST products (daytime and nighttime and auxiliary data, solving the discontinuity problem of ground measurements. There exist no studies about Vietnam that have integrated both TERRA and AQUA LST of daytime and nighttime for Ta estimation (using four MODIS LST datasets. In addition, to find out which variables are the most effective to describe the differences between LST and Ta, we have tested several popular methods, such as: the Pearson correlation coefficient, stepwise, Bayesian information criterion (BIC, adjusted R-squared and the principal component analysis (PCA of 14 variables (including: LST products (four variables, NDVI, elevation, latitude, longitude, day length in hours, Julian day and four variables of the view zenith angle, and then, we applied nine models for Ta-max estimation and nine models for Ta-min estimation. The results showed that the differences between MODIS LST and ground truth temperature derived from 15 climate stations are time and regional topography dependent. The best results for Ta-max and Ta-min estimation were achieved when we combined both LST daytime and nighttime of TERRA and AQUA and data from the topography analysis.

Distraction and mind-wandering under load.

Science.gov (United States)

Forster, Sophie

2013-01-01

Attention research over the last several decades has provided rich insights into the determinants of distraction, including distractor characteristics, task features, and individual differences. Load Theory represented a particularly important breakthrough, highlighting the critical role of the level and nature of task-load in determining both the efficiency of distractor rejection and the stage of processing at which this occurs. However, until recently studies of distraction were restricted to those measuring rather specific forms of distraction by external stimuli which I argue that, although intended to be irrelevant, were in fact task-relevant. In daily life, attention may be distracted by a wide range of stimuli, which may often be entirely unrelated to any task being performed, and may include not only external stimuli but also internally generated stimuli such as task-unrelated thoughts. This review outlines recent research examining these more general, entirely task-irrelevant, forms of distraction within the framework of Load Theory. I discuss the relation between different forms of distraction, and the universality of load effects across different distractor types and individuals.

Distraction and mind-wandering under load

Directory of Open Access Journals (Sweden)

Sophie eForster

2013-05-01

Full Text Available Attention research over the last several decades has provided rich insights into the determinants of distraction, including distractor characteristics, task features and individual differences. Load Theory represented a particularly important breakthrough, highlighting the critical role of the level and nature of task load in determining both the efficiency of distractor rejection and the stage of processing at which this occurs. However, until recently studies of distraction were restricted to those measuring rather specific forms of distraction by external stimuli which I argue that, although intended to be irrelevant, were in fact task-relevant. In daily life, attention may be distracted by a wide range of stimuli, which may often be entirely unrelated to any task being performed, and may include not only external stimuli but also internally generated stimuli such as task-unrelated thoughts. This review outlines recent research examining these more general, entirely task-irrelevant, forms of distraction within the framework of Load Theory. I discuss the relation between different forms of distraction, and the universality of load effects across different distractor types and individuals.

Unsupervised/supervised learning concept for 24-hour load forecasting

Energy Technology Data Exchange (ETDEWEB)

Djukanovic, M [Electrical Engineering Inst. ' Nikola Tesla' , Belgrade (Yugoslavia); Babic, B [Electrical Power Industry of Serbia, Belgrade (Yugoslavia); Sobajic, D J; Pao, Y -H [Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Electrical Engineering and Computer Science

1993-07-01

An application of artificial neural networks in short-term load forecasting is described. An algorithm using an unsupervised/supervised learning concept and historical relationship between the load and temperature for a given season, day type and hour of the day to forecast hourly electric load with a lead time of 24 hours is proposed. An additional approach using functional link net, temperature variables, average load and last one-hour load of previous day is introduced and compared with the ANN model with one hidden layer load forecast. In spite of limited available weather variables (maximum, minimum and average temperature for the day) quite acceptable results have been achieved. The 24-hour-ahead forecast errors (absolute average) ranged from 2.78% for Saturdays and 3.12% for working days to 3.54% for Sundays. (Author)

Heavy-Load Lifting

DEFF Research Database (Denmark)

Bloomquist, Kira; Oturai, Peter; Steele, Megan L

2018-01-01

of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal....... repetition maximum (RM), two sets of 15-20 repetitions) and heavy-load (85-90% 1RM, three sets of 5-8 repetition) upper-extremity resistance exercise separated by a one-week wash-out period. Swelling was determined by bioimpedance spectroscopy and dual energy x-ray absorptiometry, with breast cancer......-related lymphedema symptoms (heaviness, swelling, pain, tightness) reported using a numeric rating scale (0-10). Order of low- versus heavy-load was randomized. All outcomes were assessed pre-, immediately post-, and 24- and 72-hours post-exercise. Generalized estimating equations were used to evaluate changes over...

Characterization of biological particulate loads in metropolitan air

Science.gov (United States)

J. A. Snow; R. D. Schein; W. J. Moroz

1977-01-01

The atmospheric particulate load includes a wide range of naturally occurring particles of biological origin that serve as a reservoir of allergenic agents in respiratory disease. Improved knowledge of potential aeroallergens is needed by medical clinicians. Aims are to better characterize air spora, qualitatively and quantitatively, and determine daily (by hour)...

An analysis of representative heating load lines for residential HSPF ratings

Energy Technology Data Exchange (ETDEWEB)

Rice, C. Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-07-01

This report describes an analysis to investigate representative heating loads for single-family detached homes using current EnergyPlus simulations (DOE 2014a). Hourly delivered load results are used to determine binned load lines using US Department of Energy (DOE) residential prototype building models (DOE 2014b) developed by Pacific Northwest National Laboratory (PNNL). The selected residential single-family prototype buildings are based on the 2006 International Energy Conservation Code (IECC 2006) in the DOE climate regions. The resulting load lines are compared with the American National Standards Institute (ANSI)/Air-Conditioning, Heating, and Refrigeration Institute (AHRI) Standard 210/240 (AHRI 2008) minimum and maximum design heating requirement (DHR) load lines of the heating seasonal performance factor (HSPF) ratings procedure for each region. The results indicate that a heating load line closer to the maximum DHR load line, and with a lower zero load ambient temperature, is more representative of heating loads predicted for EnergyPlus prototype residential buildings than the minimum DHR load line presently used to determine HSPF ratings. An alternative heating load line equation was developed and compared to binned load lines obtained from the EnergyPlus simulation results. The effect on HSPF of the alternative heating load line was evaluated for single-speed and two-capacity heat pumps, and an average HSPF reduction of 16% was found. The alternative heating load line relationship is tied to the rated cooling capacity of the heat pump based on EnergyPlus autosizing, which is more representative of the house load characteristics than the rated heating capacity. The alternative heating load line equation was found to be independent of climate for the six DOE climate regions investigated, provided an adjustable zero load ambient temperature is used. For Region IV, the default DOE climate region used for HSPF ratings, the higher load line results in an ~28

The analysis of loading losses from tank trucks

Directory of Open Access Journals (Sweden)

Jovanović Ana P.

2006-01-01

Full Text Available The quantity of loading losses, which are the primary source of evaporative emissions from tank cars and trucks was analyzed in this paper. Loading losses occur as organic vapors in "empty" cargo tanks are displaced to the atmosphere by the liquid being loaded into the tanks. Emissions from loading petroleum liquid were estimated using three methods: the API (American Petroleum Institute method, the VDI (Verein Deutscher Ingenieure -Association of German Engineers method and the Yugoslav Standard JUS B.HO.531 method. The mass of evaporative losses from loading operations is a function of the following parameters: the method of loading the cargo, the physical and chemical characteristics of the cargo and the ambient temperature during loading. Evaporation losses from the loading of motor gasoline (MB-95, BMB-95, MB-98 and MB-86 and diesel fuels (D-2, Euro D-2 were calculated. Losses on a monthly and annual basis were presented for an assumed amount of loaded cargo. It was estimated that the highest loading losses occur in the summer period because of high ambient daily temperatures and in the period of higher transporting levels. It should be pointed out that the loading losses of diesel fuel calculated using an empirical coefficient according to JUS B.HO.531 are significantly higher in comparison with the loading losses calculated using emission factors from the EPA and the VDI method. The gasoline loading losses calculated using emission factors derived from the three methods are similar.

Development of Load Duration Curve System in Data Scarce Watersheds Based on a Distributed Hydrological Model

Science.gov (United States)

WANG, J.

2017-12-01

In stream water quality control, the total maximum daily load (TMDL) program is very effective. However, the load duration curves (LDC) of TMDL are difficult to be established because no sufficient observed flow and pollutant data can be provided in data-scarce watersheds in which no hydrological stations or consecutively long-term hydrological data are available. Although the point sources or a non-point sources of pollutants can be clarified easily with the aid of LDC, where does the pollutant come from and to where it will be transported in the watershed cannot be traced by LDC. To seek out the best management practices (BMPs) of pollutants in a watershed, and to overcome the limitation of LDC, we proposed to develop LDC based on a distributed hydrological model of SWAT for the water quality management in data scarce river basins. In this study, firstly, the distributed hydrological model of SWAT was established with the scarce-hydrological data. Then, the long-term daily flows were generated with the established SWAT model and rainfall data from the adjacent weather station. Flow duration curves (FDC) was then developed with the aid of generated daily flows by SWAT model. Considering the goal of water quality management, LDC curves of different pollutants can be obtained based on the FDC. With the monitored water quality data and the LDC curves, the water quality problems caused by the point or non-point source pollutants in different seasons can be ascertained. Finally, the distributed hydrological model of SWAT was employed again to tracing the spatial distribution and the origination of the pollutants of coming from what kind of agricultural practices and/or other human activities. A case study was conducted in the Jian-jiang river, a tributary of Yangtze river, of Duyun city, Guizhou province. Results indicate that this kind of method can realize the water quality management based on TMDL and find out the suitable BMPs for reducing pollutant in a watershed.

Variability of Bed Load Components in Different Hydrological Conditions

Directory of Open Access Journals (Sweden)

Hossein Kheirfam

2017-04-01

New hydrological insights: We found that the amount of the minimum, the mean and the maximum bed load were 3 × 10−8, 6.15 × 10−4± 7.17 × 10−4 and 4.38 × 10−3 kg s−1, respectively. The minimum, the mean, and the maximum discharge were also 60, 334 ± 215.56 and 780 l s−1, respectively. In low discharge conditions during summer, the fine grain sediments had the largest amount of bed load sediment. Coarse and medium-grained sediment transportation was higher in autumn and the early winter consistent with the occurrence of extreme rainfall and flood flows.

Effects of load on ground reaction force and lower limb kinematics during concentric squats.

Science.gov (United States)

Kellis, Eleftherios; Arambatzi, Fotini; Papadopoulos, Christos

2005-10-01

The purpose of this study was to examine the effects of external load on vertical ground reaction force, and linear and angular kinematics, during squats. Eight males aged 22.1 +/- 0.8 years performed maximal concentric squats using loads ranging from 7 to 70% of one-repetition maximum on a force plate while linear barbell velocity and the angular kinematics of the hip, knee and ankle were recorded. Maximum, average and angle-specific values were recorded. The ground reaction force ranged from 1.67 +/- 0.20 to 3.21 +/- 0.29 times body weight and increased significantly as external load increased (P squat exercises is not achieved at the same position of the lower body as external load is increased. In contrast, joint velocity coordination does not change as load is increased. The force-velocity relationship was linear and independent from the set of data used for its determination.

Creep crack growth by grain boundary cavitation under monotonic and cyclic loading

Science.gov (United States)

Wen, Jian-Feng; Srivastava, Ankit; Benzerga, Amine; Tu, Shan-Tung; Needleman, Alan

2017-11-01

Plane strain finite deformation finite element calculations of mode I crack growth under small scale creep conditions are carried out. Attention is confined to isothermal conditions and two time histories of the applied stress intensity factor: (i) a monononic increase to a plateau value subsequently held fixed; and (ii) a cyclic time variation. The crack growth calculations are based on a micromechanics constitutive relation that couples creep deformation and damage due to grain boundary cavitation. Grain boundary cavitation, with cavity growth due to both creep and diffusion, is taken as the sole failure mechanism contributing to crack growth. The influence on the crack growth rate of loading history parameters, such as the magnitude of the applied stress intensity factor, the ratio of the applied minimum to maximum stress intensity factors, the loading rate, the hold time and the cyclic loading frequency, are explored. The crack growth rate under cyclic loading conditions is found to be greater than under monotonic creep loading with the plateau applied stress intensity factor equal to its maximum value under cyclic loading conditions. Several features of the crack growth behavior observed in creep-fatigue tests naturally emerge, for example, a Paris law type relation is obtained for cyclic loading.

Determination of maximum negative Poisson's ratio for laminated fiber composites

Energy Technology Data Exchange (ETDEWEB)

Shokrieh, M.M.; Assadi, A. [Composites Research Laboratory, Mechanical Engineering Department, Center of Excellence in Experimental Solid Mechanics and Dynamics, Iran University of Science and Technology, Tehran 16846-13114 (Iran, Islamic Republic of)

2011-05-15

Contrary to isotropic materials, composites always show complicated mechanical behavior under external loadings. In this article, an efficient algorithm is employed to obtain the maximum negative Poisson's ratio for laminated composite plates. We try to simplify the problem based on normalization of parameters and some manufacturing constraints to overlook the additional constraint of the optimization procedure. A genetic algorithm is used to find the optimal thickness of each lamina with a specified fiber direction. It is observed that the laminated composite with the configuration of (15/60/15) has the maximum negative Poisson's ratio. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Variation of 210Po daily urinary excretion for male subjects at environmental level

International Nuclear Information System (INIS)

Hoelgye, Z.; Hyza, M.; Mihalik, J.; Rulik, P.; Skrkal, J.

2015-01-01

210 Po was determined in 24-h urine of seven healthy males from Prague, Czech Republic, for ten consecutive days. The results show that for each volunteer, the urinary excretion of 210 Po changed only little from day to day in the studied time period. For two volunteers, the difference in the daily excreted 210 Po activity for two consecutive days was not significant, given the 95 % confidence interval (two sigma) of the activity measurements. The same is valid for the excretion data of the other volunteers, except for some days where the differences were slightly higher. The range of daily urinary excretion of 210 Po of each volunteer in the studied time period was quite narrow. Among the volunteers, the maximum daily urinary excretion value of 210 Po was at most about a factor of 2.5 higher than the lowest excretion value. An attempt to explain the observed small inter-individual variability of 210 Po excretion in daily urine is made. (orig.)

RPE vs. Percentage 1RM Loading in Periodized Programs Matched for Sets and Repetitions

Directory of Open Access Journals (Sweden)

Eric R. Helms

2018-03-01

Full Text Available Purpose: To investigate differences between rating of perceived exertion (RPE and percentage one-repetition maximum (1RM load assignment in resistance-trained males (19–35 years performing protocols with matched sets and repetitions differentiated by load-assignment.Methods: Participants performed squats then bench press 3x/weeks in a daily undulating format over 8-weeks. Participants were counterbalanced by pre-test 1RM then assigned to percentage 1RM (1RMG, n = 11; load-assignment via percentage 1RMs, or RPE groups (RPEG, n = 10; participant-selected loads to reach target RPE ranges. Ultrasonography determined pre and post-test pectoralis (PMT, and vastus lateralis muscle thickness at 50 (VLMT50 and 70% (VLMT70 femur-length.Results: Bench press (1RMG +9.64 ± 5.36; RPEG + 10.70 ± 3.30 kg, squat (1RMG + 13.91 ± 5.89; RPEG + 17.05 ± 5.44 kg and their combined-total 1RMs (1RMG + 23.55 ± 10.38; RPEG + 27.75 ± 7.94 kg increased (p < 0.05 in both groups as did PMT (1RMG + 1.59 ± 1.33; RPEG +1.90 ± 1.91 mm, VLMT50 (1RMG +2.13 ± 1.95; RPEG + 1.85 ± 1.97 mm and VLMT70 (1RMG + 2.40 ± 2.22; RPEG + 2.31 ± 2.27 mm. Between-group differences were non-significant (p > 0.05. Magnitude-based inferences revealed 79, 57, and 72% chances of mean small effect size (ES advantages for squat; ES 90% confidence limits (CL = 0.50 ± 0.63, bench press; ES 90% CL = 0.28 ± 0.73, and combined-total; ES 90% CL = 0.48 ± 0.68 respectively, in RPEG. There were 4, 14, and 6% chances 1RMG had a strength advantage of the same magnitude, and 18, 29, and 22% chances, respectively of trivial differences between groups.Conclusions: Both loading-types are effective. However, RPE-based loading may provide a small 1RM strength advantage in a majority of individuals.

Potential role of motion for enhancing maximum output energy of triboelectric nanogenerator

Science.gov (United States)

Byun, Kyung-Eun; Lee, Min-Hyun; Cho, Yeonchoo; Nam, Seung-Geol; Shin, Hyeon-Jin; Park, Seongjun

2017-07-01

Although triboelectric nanogenerator (TENG) has been explored as one of the possible candidates for the auxiliary power source of portable and wearable devices, the output energy of a TENG is still insufficient to charge the devices with daily motion. Moreover, the fundamental aspects of the maximum possible energy of a TENG related with human motion are not understood systematically. Here, we confirmed the possibility of charging commercialized portable and wearable devices such as smart phones and smart watches by utilizing the mechanical energy generated by human motion. We confirmed by theoretical extraction that the maximum possible energy is related with specific form factors of a TENG. Furthermore, we experimentally demonstrated the effect of human motion in an aspect of the kinetic energy and impulse using varying velocity and elasticity, and clarified how to improve the maximum possible energy of a TENG. This study gives insight into design of a TENG to obtain a large amount of energy in a limited space.

Potential role of motion for enhancing maximum output energy of triboelectric nanogenerator

Directory of Open Access Journals (Sweden)

Kyung-Eun Byun

2017-07-01

Full Text Available Although triboelectric nanogenerator (TENG has been explored as one of the possible candidates for the auxiliary power source of portable and wearable devices, the output energy of a TENG is still insufficient to charge the devices with daily motion. Moreover, the fundamental aspects of the maximum possible energy of a TENG related with human motion are not understood systematically. Here, we confirmed the possibility of charging commercialized portable and wearable devices such as smart phones and smart watches by utilizing the mechanical energy generated by human motion. We confirmed by theoretical extraction that the maximum possible energy is related with specific form factors of a TENG. Furthermore, we experimentally demonstrated the effect of human motion in an aspect of the kinetic energy and impulse using varying velocity and elasticity, and clarified how to improve the maximum possible energy of a TENG. This study gives insight into design of a TENG to obtain a large amount of energy in a limited space.

Intent to Quit among Daily and Non-Daily College Student Smokers

Science.gov (United States)

Pinsker, E. A.; Berg, C. J.; Nehl, E. J.; Prokhorov, A. V.; Buchanan, T. S.; Ahluwalia, J. S.

2013-01-01

Given the high prevalence of young adult smoking, we examined (i) psychosocial factors and substance use among college students representing five smoking patterns and histories [non-smokers, quitters, native non-daily smokers (i.e. never daily smokers), converted non-daily smokers (i.e. former daily smokers) and daily smokers] and (ii) smoking…

Identifying the Correlation between Water Quality Data and LOADEST Model Behavior in Annual Sediment Load Estimations

Directory of Open Access Journals (Sweden)

Youn Shik Park

2016-08-01

Full Text Available Water quality samples are typically collected less frequently than flow since water quality sampling is costly. Load Estimator (LOADEST, provided by the United States Geological Survey, is used to predict water quality concentration (or load on days when flow data are measured so that the water quality data are sufficient for annual pollutant load estimation. However, there is a need to identify water quality data requirements for accurate pollutant load estimation. Measured daily sediment data were collected from 211 streams. Estimated annual sediment loads from LOADEST and subsampled data were compared to the measured annual sediment loads (true load. The means of flow for calibration data were correlated to model behavior. A regression equation was developed to compute the required mean of flow in calibration data to best calibrate the LOADEST regression model coefficients. LOADEST runs were performed to investigate the correlation between the mean flow in calibration data and model behaviors as daily water quality data were subsampled. LOADEST calibration data used sediment concentration data for flows suggested by the regression equation. Using the mean flow calibrated by the regression equation reduced errors in annual sediment load estimation from −39.7% to −10.8% compared to using all available data.

Cognitive Load in Voice Therapy Carry-Over Exercises

Science.gov (United States)

Iwarsson, Jenny; Morris, David Jackson; Balling, Laura Winther

2017-01-01

Purpose: The cognitive load generated by online speech production may vary with the nature of the speech task. This article examines 3 speech tasks used in voice therapy carry-over exercises, in which a patient is required to adopt and automatize new voice behaviors, ultimately in daily spontaneous communication. Method: Twelve subjects produced…

Unknown loads affect force production capacity in early phases of bench press throws.

Science.gov (United States)

Hernández Davó, J L; Sabido Solana, R; Sarabia Marínm, J M; Sánchez Martos, Á; Moya Ramón, M

2015-10-01

Explosive strength training aims to improve force generation in early phases of movement due to its importance in sport performance. The present study examined the influence of lack of knowledge about the load lifted in explosive parameters during bench press throws. Thirteen healthy young men (22.8±2.0 years) participated in the study. Participants performed bench press throws with three different loads (30, 50 and 70% of 1 repetition maximum) in two different conditions (known and unknown loads). In unknown condition, loads were changed within sets in each repetition and participants did not know the load, whereas in known condition the load did not change within sets and participants had knowledge about the load lifted. Results of repeated-measures ANOVA revealed that unknown conditions involves higher power in the first 30, 50, 100 and 150 ms with the three loads, higher values of ratio of force development in those first instants, and differences in time to reach maximal rate of force development with 50 and 70% of 1 repetition maximum. This study showed that unknown conditions elicit higher values of explosive parameters in early phases of bench press throws, thereby this kind of methodology could be considered in explosive strength training.

A combined stochastic analysis of mean daily temperature and diurnal temperature range

Science.gov (United States)

Sirangelo, B.; Caloiero, T.; Coscarelli, R.; Ferrari, E.

2018-03-01

In this paper, a stochastic model, previously proposed for the maximum daily temperature, has been improved for the combined analysis of mean daily temperature and diurnal temperature range. In particular, the procedure applied to each variable sequentially performs the deseasonalization, by means of truncated Fourier series expansions, and the normalization of the temperature data, with the use of proper transformation functions. Then, a joint stochastic analysis of both the climatic variables has been performed by means of a FARIMA model, taking into account the stochastic dependency between the variables, namely introducing a cross-correlation between the standardized noises. The model has been applied to five daily temperature series of southern Italy. After the application of a Monte Carlo simulation procedure, the return periods of the joint behavior of the mean daily temperature and the diurnal temperature range have been evaluated. Moreover, the annual maxima of the temperature excursions in consecutive days have been analyzed for the synthetic series. The results obtained showed different behaviors probably linked to the distance from the sea and to the latitude of the station.

Integrated microelectromechanical gyroscope under shock loads

Science.gov (United States)

Nesterenko, T. G.; Koleda, A. N.; Barbin, E. S.

2018-01-01

The paper presents a new design of a shock-proof two-axis microelectromechanical gyroscope. Without stoppers, the shock load enables the interaction between the silicon sensor elements. Stoppers were installed in the gyroscope to prevent the contact interaction between electrodes and spring elements with fixed part of the sensor. The contact of stoppers occurs along the plane, thereby preventing the system from serious contact stresses. The shock resistance of the gyroscope is improved by the increase in its eigenfrequency at which the contact interaction does not occur. It is shown that the shock load directed along one axis does not virtually cause the movement of sensing elements along the crosswise axes. Maximum stresses observed in the proposed gyroscope at any loading direction do not exceed the value allowable for silicon.

Loss-of-load probabilities for stand-alone photovoltaic systems

International Nuclear Information System (INIS)

Klein, S.A.; Beckman, W.A.

1989-01-01

A general method is presented for estimating the loss-of-load probability of stand-alone photovoltaic systems. The method was developed by correlating simulation results. The simulations were driven with synthetic radiation sequences having the same statistical significance as available historical data. The methods assumes a constant nighttime load and accounts for the distribution and persistence in daily solar radiation data. It is shown that the 10 year average performance of systems having loss-of-load probabilities less than about 0.01 can vary greatly from one ten year period to the next and thereby cannot be considered realistic performance estimates of a system during its lifetime. (author). 26 refs, 15 figs, 4 tabs

Determination of maximum power transfer conditions of bimorph piezoelectric energy harvesters

KAUST Repository

Ahmad, Mahmoud Al

2012-07-23

In this paper, a method to find the maximum power transfer conditions in bimorph piezoelectric-based harvesters is proposed. Explicitly, we derive a closed form expression that relates the load resistance to the mechanical parameters describing the bimorph based on the electromechanical, single degree of freedom, analogy. Further, by taking into account the intrinsic capacitance of the piezoelectric harvester, a more descriptive expression of the resonant frequency in piezoelectric bimorphs was derived. In interest of impartiality, we apply the proposed philosophy on previously published experimental results and compare it with other reported hypotheses. It was found that the proposed method was able to predict the actual optimum load resistance more accurately than other methods reported in the literature. © 2012 American Institute of Physics.

Comparison of fuzzy logic and neural network in maximum power point tracker for PV systems

Energy Technology Data Exchange (ETDEWEB)

Ben Salah, Chokri; Ouali, Mohamed [Research Unit on Intelligent Control, Optimization, Design and Optimization of Complex Systems (ICOS), Department of Electrical Engineering, National School of Engineers of Sfax, BP. W, 3038, Sfax (Tunisia)

2011-01-15

This paper proposes two methods of maximum power point tracking using a fuzzy logic and a neural network controllers for photovoltaic systems. The two maximum power point tracking controllers receive solar radiation and photovoltaic cell temperature as inputs, and estimated the optimum duty cycle corresponding to maximum power as output. The approach is validated on a 100 Wp PVP (two parallels SM50-H panel) connected to a 24 V dc load. The new method gives a good maximum power operation of any photovoltaic array under different conditions such as changing solar radiation and PV cell temperature. From the simulation and experimental results, the fuzzy logic controller can deliver more power than the neural network controller and can give more power than other different methods in literature. (author)

Element Load Data Processor (ELDAP) Users Manual

Science.gov (United States)

Ramsey, John K., Jr.; Ramsey, John K., Sr.

2015-01-01

Often, the shear and tensile forces and moments are extracted from finite element analyses to be used in off-line calculations for evaluating the integrity of structural connections involving bolts, rivets, and welds. Usually the maximum forces and moments are desired for use in the calculations. In situations where there are numerous structural connections of interest for numerous load cases, the effort in finding the true maximum force and/or moment combinations among all fasteners and welds and load cases becomes difficult. The Element Load Data Processor (ELDAP) software described herein makes this effort manageable. This software eliminates the possibility of overlooking the worst-case forces and moments that could result in erroneous positive margins of safety and/or selecting inconsistent combinations of forces and moments resulting in false negative margins of safety. In addition to forces and moments, any scalar quantity output in a PATRAN report file may be evaluated with this software. This software was originally written to fill an urgent need during the structural analysis of the Ares I-X Interstage segment. As such, this software was coded in a straightforward manner with no effort made to optimize or minimize code or to develop a graphical user interface.

Chronic and Daily Stressors Along With Negative Affect Interact to Predict Daily Tiredness.

Science.gov (United States)

Hartsell, Elizabeth N; Neupert, Shevaun D

2017-11-01

The present study examines the within-person relationship of daily stressors and tiredness and whether this depends on daily negative affect and individual differences in chronic stress. One hundred sixteen older adult participants were recruited via Amazon's Mechanical Turk for a 9-day daily diary study. Daily tiredness, daily stressors, and negative affect were measured each day, and chronic stress was measured at baseline. Daily stressors, daily negative affect, and chronic stress interacted to predict daily tiredness. People with high chronic stress who experienced an increase in daily negative affect were the most reactive to daily stressors in terms of experiencing an increase in daily tiredness. We also found that people with low levels of chronic stress were the most reactive to daily stressors when they experienced low levels of daily negative affect. Our results highlight the need for individualized and contextualized approaches to combating daily tiredness in older adults.

Minimum weight design of composite laminates for multiple loads

International Nuclear Information System (INIS)

Krikanov, A.A.; Soni, S.R.

1995-01-01

A new design method of constructing optimum weight composite laminates for multiple loads is proposed in this paper. A netting analysis approach is used to develop an optimization procedure. Three ply orientations permit development of optimum laminate design without using stress-strain relations. It is proved that stresses in minimum weight laminate reach allowable values in each ply with given load. The optimum ply thickness is defined at maximum value among tensile and compressive loads. Two examples are given to obtain optimum ply orientations, thicknesses and materials. For comparison purposes, calculations of stresses are done in orthotropic material using classical lamination theory. Based upon these calculations, matrix degrades at 30 to 50% of ultimate load. There is no fiber failure and therefore laminates withstand all applied loads in both examples

Involuntary autobiographical memories are relatively more often reported during high cognitive load tasks.

Science.gov (United States)

Barzykowski, Krystian; Niedźwieńska, Agnieszka

2018-01-01

Recent studies on involuntary autobiographical memories (IAMs) in daily life have shown that they are most frequently reported during daily routines (e.g. while ironing). Such studies have suggested that reporting IAMs may be influenced by the level of the ongoing task demands and availability of cognitive resources. In two studies, we investigated the effects of cognitive load on reporting IAMs. To examine the presumed cognitive load dependency of IAMs, we utilised an often-employed experimental paradigm (Schlagman & Kvavilashvili, 2008) to elicit IAMs under conditions that differed in cognitive load. When performing a vigilance task, participants had to interrupt the task each time they experienced any spontaneous mental contents and write them down. We manipulated the level of cognitive load by either instructing (cognitive load group) or not instructing (control group) participants to perform an additional demanding task. We compared the groups on the number of IAMs and other mental contents (non-IAM contents) recorded, as well as on the frequency of IAMs that was calculated as a proportion of IAMs in all mental contents reported by the participant. We expected that if reporting IAMs depends on the level of cognitive demands, then we should observe lower frequency of IAMs in the cognitive load group compared to the control group. Consistently across studies, we observed a lower number of IAMs and non-IAM contents in the cognitive load group. However, IAMs unexpectedly constituted a higher percentage of all mental contents when participants were cognitively loaded. Further implications of the cognitive load effects for IAMs research and experimental methodology are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Reliability-Based Calibration of Load Duration Factors for Timber Structures

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Svensson, Staffan; Stang, Birgitte Friis Dela

2005-01-01

John Dalsgaard Sørensen, Staffan Svensson, Birgitte Dela Stang : Reliability-Based Calibration of Load Duration Factors for Timber Structures     Abstract :   The load bearing capacity of timber structures decrease with time depending on the type of load and timber. Based on representative limit...... states and stochastic models for timber structures, load duration factors are calibrated using probabilistic methods. Load duration e.ects are estimated on basis of simulation of realizations of wind, snow and imposed loads in accordance with the load models in the Danish structural codes. Three damage...... accumulation models are considered, namely Gerhards model, Barrett and Foschi _ s model and Foschi and Yao _ s model. The parameters in these models are .tted by the Maximum Likelihood Method using data relevant for Danish structural timber and the statistical uncertainty is quanti .ed. The reliability...

Transposing Concentration-Discharge Curves onto Unmonitored Catchments to Estimate Seasonal Nutrient Loads

Science.gov (United States)

Minaudo, C.; Moatar, F.; Abbott, B. W.; Dupas, R.; Gascuel-Odoux, C.; Pinay, G.; Roubeix, V.; Danis, P. A.

2017-12-01

Many lakes and reservoirs in Europe suffer from severe eutrophication. Accurate quantification of nutrient loads are critical for effective mitigation measures, but this information is often unknown. For example, in France, only 50 out of 481 lakes and reservoirs have national monitoring allowing estimation of interannual nitrogen and phosphorus loads, and even these loads are computed from low-frequency data. To address this lack of data, we developed a straightforward method to predict seasonal loads in lake tributaries. First, we analyzed concentration-discharge (C-Q) curves in monitored catchments and identified slopes, intercepts, and coefficient of variation of the log(C)-log(Q) regressions determined for both low and high flows, separated by the median daily flow [Moatar et al., 2017]. Then, we used stepwise multiple linear regression models to empirically link the characteristics of C-Q curves with a set of catchment descriptors such as land use, lithology, morphology indices, climate, and hydrological indicators. Modeled C-Q relationships were then used to estimate annual and seasonal nutrient loads in nearby and similar unmonitored catchments. We implemented this approach on a large dataset from France where stream flow was surveyed daily and water quality (suspended solids, nitrate, total phosphorus, and orthophosphate concentrations) was measured on a monthly basis at 233 stations over the past 20 years in catchments from 10 to 3000 km². The concentration at the median daily flow (seen here as a metric of the general level of contamination in a catchment) was predicted with uncertainty ranging between 30 and 100 %, depending on the variable. C-Q slopes were predicted with large errors, but a sensitivity analysis was conducted to determine the impact of C-Q slopes uncertainties on computed annual and seasonal loads. This approach allows estimation of seasonal and annual nutrient loads and could be potentially implemented to improve protection and

Short term and medium term power distribution load forecasting by neural networks

International Nuclear Information System (INIS)

Yalcinoz, T.; Eminoglu, U.

2005-01-01

Load forecasting is an important subject for power distribution systems and has been studied from different points of view. In general, load forecasts should be performed over a broad spectrum of time intervals, which could be classified into short term, medium term and long term forecasts. Several research groups have proposed various techniques for either short term load forecasting or medium term load forecasting or long term load forecasting. This paper presents a neural network (NN) model for short term peak load forecasting, short term total load forecasting and medium term monthly load forecasting in power distribution systems. The NN is used to learn the relationships among past, current and future temperatures and loads. The neural network was trained to recognize the peak load of the day, total load of the day and monthly electricity consumption. The suitability of the proposed approach is illustrated through an application to real load shapes from the Turkish Electricity Distribution Corporation (TEDAS) in Nigde. The data represents the daily and monthly electricity consumption in Nigde, Turkey

A Study on Assessment Method of Traffic Load Effect of Bridge in Service

Science.gov (United States)

Ling, Pan; Dajian, Han

2010-05-01

Because of overloading usually occur in highway in China today, it is found that the traffic load and the load effects given by Specification for Inspection and Evaluation of Load-bearing Capacity of Highway Bridge[1] cannot be adequately estimated. Especially, the extreme values in a service period can not be predicted. In this paper, a model is first developed for a better estimation of the actual traffic flow, as well as the service load effect level of a bridge. Based on a five-day collection data of the vehicle samples passing through the exit of Guangyuan to Shahe of the North-Ring Highway in Guangzhou, The Qiaole Bridge of the highway is taken as an example to illustrate the assessment model. Then, a threshold model is applied to estimate the tail distribution of the maximum load effect of a fleet. And threshold point process is used to infer the maximum value distribution for prediction of the load effect level of the bridge in a future time period. Finally, a 0.95 quantile is obtained to compare with the result given by specification[1]. The results show that the assessment method proposed in this paper is valid and feasible.

Investigation of Breakpoint and Trend of Daily Air Temperature Range for Mashhad, Iran

Directory of Open Access Journals (Sweden)

shideh shams

2017-01-01

Full Text Available Introduction: Air temperature as an important climatic factor can influence variability and distribution of other climatic parameters. Therefore, tracking the changes in air temperature is a popular procedure in climate change studies.. According to the national academy in the last decade, global temperature has raised 0.4 to 0.8⁰C. Instrumental records show that, with the exception of 1998, the 10 warmest year (during the last 150 years, occurred since 2000, and 2014 was the warmest year. Investigation of maximum and minimum air temperature temporal trend indicates that these two parameters behave differently over time. It has been shown that the minimum air temperature raises noticeably more than the maximum air temperature, which causes a reduction in the difference of maximum and minimum daily air temperature (daily temperature range, DTR. There are several factors that have an influence on reducing DTR such as: Urban development, farms’ irrigation and desertification. It has been shown that DTR reduction occurs mostly during winter and is less frequent during summer, which shows the season’s effect on the temperature trend. Considering the significant effects of the climatological factors on economic and agricultural management issues, the aim of this study is to investigate daily air temperature range for yearly, seasonal and monthly time scales, using available statistical methods. Materials and Methods: Daily maximum and minimum air temperature records (from 1950 to 2010 were obtained from Mashhad Meteorological Organization. In order to control the quality of daily Tmax and Tmin data, four different types of quality controls were applied. First of all, gross errors were checked. In this step maximum and minimum air temperature data exceeding unlikely air temperature values, were eliminated from data series. Second, data tolerance was checked by searching for periods longer than a certain number of consecutive days with exactly the

The effect of oral zinc loading on the absorption of 65Zinc in the rat

International Nuclear Information System (INIS)

Hoyer, H.; Weismann, K.

1979-01-01

Seven groups of 8 rats each were orally loaded with zinc, the daily dose varying from 1.8 to 58 mg, corresponding to about 3 to 100 times of their estimated daily intake of zinc. To record the absorption of zinc, the rats were given a single dose of 65 Zn. The rentention of the isotope was measured in a whole animal counter at regular intervals. The dose of 58mg was obviously toxis, since half of the animals died within 5 days. The net absorption of zinc in the remaining experimental groups was found to vary from about 7% in the group receiving the smallest loading dose to 1.8% in the group receiving the highest dose. From the absorption values, as determined by extrapolation of semilog retention curves, the total amount of absorbed zinc was estimated. It was found to differ from about 170μg to about 530μg zinc daily, increasing three times as the loading dose was increased 16 times. This discrepancy suggests the existence of regulatory mechanisms of the absorption of zinc from the intestine. (orig.) [de

Droop Control of Solar PV, Grid and Critical Load using Suppressing DC Current Injection Technique without Battery Storage

Science.gov (United States)

Dama Mr., Jayachandra; (Mrs. , Lini Mathew, Dr.; Srikanth Mr., G.

2017-08-01

This paper presents design of a sustainable solar Photo voltaic system for an Indian cities based residential/community house, integrated with grid, supporting it as supplementary sources, to meet energy demand of domestic loads. The role of renewable energy sources in Distributed Generation (DG) is increasingly being recognized as a supplement and an alternative to large conventional central power supply. Though centralized economic system that solely depends on cities is hampered due to energy deficiency, the use of solar energy in cities is never been tried widely due to technical inconvenience and high installation cost. To mitigate these problems, this paper proposes an optimized design of grid-tied PV system without storage which is suitable for Indian origin as it requires less installallation cost and supplies residential loads when the grid power is unavailable. The energy requirement is mainly fulfilled from PV energy module for critical load of a city located residential house and supplemented by grid/DG for base and peak load. The system has been developed for maximum daily household demand of 50kWp and can be scaled to any higher value as per requirement of individual/community building ranging from 50kWp to 60kWp as per the requirement. A simplified control system model has been developed to optimize and control flow of power from these sources. The simulation work, using MATLAB Simulink software for proposed energy management, has resulted in an optimal yield leading efficient power flow control of proposed system.

Impacts of climate change on TN load and its control in a River Basin with complex pollution sources.

Science.gov (United States)

Yang, Xiaoying; Warren, Rachel; He, Yi; Ye, Jinyin; Li, Qiaoling; Wang, Guoqing

2018-02-15

It is increasingly recognized that climate change could affect the quality of water through complex natural and anthropogenic mechanisms. Previous studies on climate change and water quality have mostly focused on assessing its impact on pollutant loads from agricultural runoff. A sub-daily SWAT model was developed to simulate the discharge, transport, and transformation of nitrogen from all known anthropogenic sources including industries, municipal sewage treatment plants, concentrated and scattered feedlot operations, rural households, and crop production in the Upper Huai River Basin. This is a highly polluted basin with total nitrogen (TN) concentrations frequently exceeding Class V of the Chinese Surface Water Quality Standard (GB3838-2002). Climate change projections produced by 16 Global Circulation Models (GCMs) under the RCP 4.5 and RCP 8.5 scenarios in the mid (2040-2060) and late (2070-2090) century were used to drive the SWAT model to evaluate the impacts of climate change on both the TN loads and the effectiveness of three water pollution control measures (reducing fertilizer use, constructing vegetative filter strips, and improving septic tank performance) in the basin. SWAT simulation results have indicated that climate change is likely to cause an increase in both monthly average and extreme TN loads in February, May, and November. The projected impact of climate change on TN loads in August is more varied between GCMs. In addition, climate change is projected to have a negative impact on the effectiveness of septic tanks in reducing TN loads, while its impacts on the other two measures are more uncertain. Despite the uncertainty, reducing fertilizer use remains the most effective measure for reducing TN loads under different climate change scenarios. Meanwhile, improving septic tank performance is relatively more effective in reducing annual TN loads, while constructing vegetative filter strips is more effective in reducing annual maximum monthly

Intent to quit among daily and non-daily college student smokers

OpenAIRE

Pinsker, E. A.; Berg, C. J.; Nehl, E. J.; Prokhorov, A. V.; Buchanan, T. S.; Ahluwalia, J. S.

2012-01-01

Given the high prevalence of young adult smoking, we examined (i) psychosocial factors and substance use among college students representing five smoking patterns and histories [non-smokers, quitters, native non-daily smokers (i.e. never daily smokers), converted non-daily smokers (i.e. former daily smokers) and daily smokers] and (ii) smoking category as it relates to readiness to quit among current smokers. Of the 4438 students at six Southeast colleges who completed an online survey, 69.7%...

Load Deflection Characteristics of Nickel Titanium Initial Archwires

Directory of Open Access Journals (Sweden)

Hossein Aghili

2016-05-01

Full Text Available Objectives: The aim of this study was to assess and compare the characteristics of commonly used initial archwires by their load deflection graphs.Materials and Methods: This study tested three wire designs namely copper nickel titanium (CNT, nickel titanium (NiTi, and multi-strand NiTi (MSNT archwires engaged in passive self-ligating (PSL brackets, active self-ligating (ASL brackets or conventional brackets. To evaluate the mechanical characteristics of the specimens, a three-point bending test was performed. The testing machine vertically applied force on the midpoint of the wire between the central incisor and canine teeth to obtain 2 and 4mm of deflection. The force level at maximum deflection and characteristics of plateau (the average plateau load and the plateau length were recorded. Two-way ANOVA and Tukey’s test were used at P <0.05 level of significance.Results: Force level at maximum deflection and plateau length were significantly affected by the amount of deflection. The type of archwires and brackets had significant effects on force level at maximum deflection, and plateau length. However, the bracket type had no significant effect on the average plateau force.Conclusion: With any type of brackets in deflections of 2 and 4mm, MSNT wire exerted the lowest while NiTi wire exerted the highest force level at maximum deflection and plateau phase. The force level at maximum deflection and the plateau length increased with raising the amount of primary deflection; however the average plateau force did not change significantly.

Temporal variability of daily personal magnetic field exposure metrics in pregnant women.

Science.gov (United States)

Lewis, Ryan C; Evenson, Kelly R; Savitz, David A; Meeker, John D

2015-01-01

Recent epidemiology studies of power-frequency magnetic fields and reproductive health have characterized exposures using data collected from personal exposure monitors over a single day, possibly resulting in exposure misclassification due to temporal variability in daily personal magnetic field exposure metrics, but relevant data in adults are limited. We assessed the temporal variability of daily central tendency (time-weighted average, median) and peak (upper percentiles, maximum) personal magnetic field exposure metrics over 7 consecutive days in 100 pregnant women. When exposure was modeled as a continuous variable, central tendency metrics had substantial reliability, whereas peak metrics had fair (maximum) to moderate (upper percentiles) reliability. The predictive ability of a single-day metric to accurately classify participants into exposure categories based on a weeklong metric depended on the selected exposure threshold, with sensitivity decreasing with increasing exposure threshold. Consistent with the continuous measures analysis, sensitivity was higher for central tendency metrics than for peak metrics. If there is interest in peak metrics, more than 1 day of measurement is needed over the window of disease susceptibility to minimize measurement error, but 1 day may be sufficient for central tendency metrics.

Model for predicting non-linear crack growth considering load sequence effects (LOSEQ)

International Nuclear Information System (INIS)

Fuehring, H.

1982-01-01

A new analytical model for predicting non-linear crack growth is presented which takes into account the retardation as well as the acceleration effects due to irregular loading. It considers not only the maximum peak of a load sequence to effect crack growth but also all other loads of the history according to a generalised memory criterion. Comparisons between crack growth predicted by using the LOSEQ-programme and experimentally observed data are presented. (orig.) [de

Behavior of quenched and tempered steels under high strain rate compression loading

International Nuclear Information System (INIS)

Meyer, L.W.; Seifert, K.; Abdel-Malek, S.

1997-01-01

Two quenched and tempered steels were tested under compression loading at strain rates of ε = 2.10 2 s -1 and ε = 2.10 3 s -1 . By applying the thermal activation theory, the flow stress at very high strain rates of 10 5 to 10 6 s -1 is derived from low temperature and high strain rate tests. Dynamic true stress - true strain behaviour presents, that stress increases with increasing strain until a maximum, then it decreases. Because of the adiabatic process under dynamic loading the maximum flow stress will occur at a lower strain if the strain rate is increased. Considering strain rate, strain hardening, strain rate hardening and strain softening, a constitutive equation with different additive terms is successfully used to describe the behaviour of material under dynamic compression loading. Results are compared with other models of constitutive equations. (orig.)

A maximum power point tracking algorithm for photovoltaic applications

Science.gov (United States)

Nelatury, Sudarshan R.; Gray, Robert

2013-05-01

The voltage and current characteristic of a photovoltaic (PV) cell is highly nonlinear and operating a PV cell for maximum power transfer has been a challenge for a long time. Several techniques have been proposed to estimate and track the maximum power point (MPP) in order to improve the overall efficiency of a PV panel. A strategic use of the mean value theorem permits obtaining an analytical expression for a point that lies in a close neighborhood of the true MPP. But hitherto, an exact solution in closed form for the MPP is not published. This problem can be formulated analytically as a constrained optimization, which can be solved using the Lagrange method. This method results in a system of simultaneous nonlinear equations. Solving them directly is quite difficult. However, we can employ a recursive algorithm to yield a reasonably good solution. In graphical terms, suppose the voltage current characteristic and the constant power contours are plotted on the same voltage current plane, the point of tangency between the device characteristic and the constant power contours is the sought for MPP. It is subject to change with the incident irradiation and temperature and hence the algorithm that attempts to maintain the MPP should be adaptive in nature and is supposed to have fast convergence and the least misadjustment. There are two parts in its implementation. First, one needs to estimate the MPP. The second task is to have a DC-DC converter to match the given load to the MPP thus obtained. Availability of power electronics circuits made it possible to design efficient converters. In this paper although we do not show the results from a real circuit, we use MATLAB to obtain the MPP and a buck-boost converter to match the load. Under varying conditions of load resistance and irradiance we demonstrate MPP tracking in case of a commercially available solar panel MSX-60. The power electronics circuit is simulated by PSIM software.

Analysis of factors that influence the maximum number of repetitions in two upper-body resistance exercises: curl biceps and bench press.

Science.gov (United States)

Iglesias, Eliseo; Boullosa, Daniel A; Dopico, Xurxo; Carballeira, Eduardo

2010-06-01

The purpose of this study was to analyze the influence of exercise type, set configuration, and relative intensity load on relationship between 1 repetition maximum (1RM) and maximum number of repetitions (MNR). Thirteen male subjects, experienced in resistance training, were tested in bench press and biceps curl for 1RM, MNR at 90% of 1RM with cluster set configuration (rest of 30s between repetitions) and MNR at 70% of 1RM with traditional set configuration (no rest between repetitions). A lineal encoder was used for measuring displacement of load. Analysis of variance analysis revealed a significant effect of load (pbench press and biceps curl, respectively; pbench press and biceps curl, respectively; p>0.05). Correlation between 1RM and MNR was significant for medium-intensity in biceps curl (r=-0.574; pvelocity along set, so velocity seems to be similar at a same relative intensity for subjects with differences in maximum strength levels. From our results, we suggest the employment of MNR rather than % of 1RM for training monitoring. Furthermore, we suggest the introduction of cluster set configuration for upper-body assessment of MNR and for upper-body muscular endurance training at high-intensity loads, as it seems an efficient approach in looking for sessions with greater training volumes. This could be an interesting approach for such sports as wrestling or weightlifting.

A European daily high-resolution gridded dataset of surface temperature and precipitation for 1950-2006

NARCIS (Netherlands)

Haylock, M.; Hofstra, N.; Klein Tank, A.; Klok, L.; Jones, P.; New, M.

2008-01-01

We present a European land-only daily high-resolution gridded data set for precipitation and minimum, maximum, and mean surface temperature for the period 1950–2006. This data set improves on previous products in its spatial resolution and extent, time period, number of contributing stations, and

Seasonal player wellness and its longitudinal association with internal training load: study in elite volleyball.

Science.gov (United States)

Clemente, Filipe M; Mendes, Bruno; Palao, José M; Silvério, André; Carriço, Sandro; Calvete, Francisco; Nakamura, Fábio Y

2018-04-04

Monitoring training load is critical to minimize the risk of overreaching, injury or illness. The purpose of this study was to assess the relationships and variance between perceived internal load and wellness status of elite male volleyball. Thirteen elite volleyball players were studied during a full competitive season (nine months, 237 training sessions and 37 official matches). Perceived exertion, muscle soreness, stress, fatigue and sleep quality levels were daily measured using session RPE and the Hopper Questionnaire. Moderate-to-large correlations were found between weekly training load and perceived status of muscle soreness, fatigue and stress. Stronger correlations were found between weekly training loads than daily training load. Significant greater stress levels in match days than in training were found. No correlations between load and wellness were not found in the last month when players perceived higher levels of stress due to the competition. The analysis of the weekly training load had a higher relationship with players' wellness status in pre-season and middle of the season. In the last part of the season (final matches for the title), despite of a decrease in perceived load of last month of the season, there was an increase stress and fatigue levels. These results suggest the importance of including the impact on the competition when elite athletes are monitored. The results show the monitoring tools used may help in to characterize the training process of teams and the player's acute and chronic responses.

Probabilistic representation of duration of load effects in timber structures

DEFF Research Database (Denmark)

Svensson, Staffan

2011-01-01

Reliability analysis of structures for the purpose of code calibration or reliability verification of specific structures requires that the relevant failure modes are represented and analyzed. For structural timber, sustaining a life load, two failure cases for each failure mode have......-based design of timber structures in terms of a modification factor View the MathML source which is multiplied on the short-term resistance of the timber material. The scenario of a beam subject to office space life loads is analyzed and the modification factor View the MathML source is calibrated by using...... to be considered. These two cases are maximum load level exceeding load-carrying capacity and damage accumulation (caused by the load and its duration) leading to failure. The effect of both load intensity and load duration on the capacity of timber has been an area of large interest over the last decades...

New algorithm using only one variable measurement applied to a maximum power point tracker

Energy Technology Data Exchange (ETDEWEB)

Salas, V.; Olias, E.; Lazaro, A.; Barrado, A. [University Carlos III de Madrid (Spain). Dept. of Electronic Technology

2005-05-01

A novel algorithm for seeking the maximum power point of a photovoltaic (PV) array for any temperature and solar irradiation level, needing only the PV current value, is proposed. Satisfactory theoretical and experimental results are presented and were obtained when the algorithm was included on a 100 W 24 V PV buck converter prototype, using an inexpensive microcontroller. The load of the system used was a battery and a resistance. The main advantage of this new maximum power point tracking (MPPT), when is compared with others, is that it only uses the measurement of the photovoltaic current, I{sub PV}. (author)

Using the load-velocity relationship for 1RM prediction.

Science.gov (United States)

Jidovtseff, Boris; Harris, Nigel K; Crielaard, Jean-Michel; Cronin, John B

2011-01-01

The purpose of this study was to investigate the ability of the load-velocity relationship to accurately predict a bench press 1 repetition maximum (1RM). Data from 3 different bench press studies (n = 112) that incorporated both 1RM assessment and submaximal load-velocity profiling were analyzed. Individual regression analysis was performed to determine the theoretical load at zero velocity (LD0). Data from each of the 3 studies were analyzed separately and also presented as overall group mean. Thereafter, correlation analysis provided quantification of the relationships between 1RM and LD0. Practically perfect correlations (r = ∼0.95) were observed in our samples, confirming the ability of the load-velocity profile to accurately predict bench press 1RM.

A novel algorithm for single-axis maximum power generation sun trackers

International Nuclear Information System (INIS)

Lee, Kung-Yen; Chung, Chi-Yao; Huang, Bin-Juine; Kuo, Ting-Jung; Yang, Huang-Wei; Cheng, Hung-Yen; Hsu, Po-Chien; Li, Kang

2017-01-01

Highlights: • A novel algorithm for a single-axis sun tracker is developed to increase the efficiency. • Photovoltaic module is rotated to find the optimal angle for generating the maximum power. • Electric energy increases up to 8.3%, compared with that of the tracker with three fixed angles. • The rotation range is optimized to reduce energy consumption from the rotation operations. - Abstract: The purpose of this study is to develop a novel algorithm for a single-axis maximum power generation sun tracker in order to identify the optimal stopping angle for generating the maximum amount of daily electric energy. First, the photovoltaic modules of the single-axis maximum power generation sun tracker are automatically rotated from 50° east to 50° west. During the rotation, the instantaneous power generated at different angles is recorded and compared, meaning that the optimal angle for generating the maximum power can be determined. Once the rotation (detection) is completed, the photovoltaic modules are then rotated to the resulting angle for generating the maximum power. The photovoltaic module is rotated once per hour in an attempt to detect the maximum irradiation and overcome the impact of environmental effects such as shading from cloud cover, other photovoltaic modules and surrounding buildings. Furthermore, the detection range is halved so as to reduce the energy consumption from the rotation operations and to improve the reliability of the sun tracker. The results indicate that electric energy production is increased by 3.4% in spring and autumn, 5.4% in summer, and 8.3% in winter, compared with that of the same sun tracker with three fixed angles of 50° east in the morning, 0° at noon and 50° west in the afternoon.

Gain-scheduled {{\\mathscr{H}}}_{\\infty } buckling control of a circular beam-column subject to time-varying axial loads

Science.gov (United States)

Schaeffner, Maximilian; Platz, Roland

2018-06-01

For slender beam-columns loaded by axial compressive forces, active buckling control provides a possibility to increase the maximum bearable axial load above that of a purely passive structure. In this paper, an approach for gain-scheduled {{\\mathscr{H}}}∞ buckling control of a slender beam-column with circular cross-section subject to time-varying axial loads is investigated experimentally. Piezo-elastic supports with integrated piezoelectric stack actuators at the beam-column ends allow an active stabilization in arbitrary lateral directions. The axial loads on the beam-column influence its lateral dynamic behavior and, eventually, cause the beam-column to buckle. A reduced modal model of the beam-column subject to axial loads including the dynamics of the electrical components is set up and calibrated with experimental data. Particularly, the linear parameter-varying open-loop plant is used to design a model-based gain-scheduled {{\\mathscr{H}}}∞ buckling control that is implemented in an experimental test setup. The beam-column is loaded by ramp- and step-shaped time-varying axial compressive loads that result in a lateral deformation of the beam-column due to imperfections, such as predeformation, eccentric loading or clamping moments. The lateral deformations and the maximum bearable loads of the beam-column are analyzed and compared for the beam-column with and without gain-scheduled {{\\mathscr{H}}}∞ buckling control or, respectively, active and passive configuration. With the proposed gain-scheduled {{\\mathscr{H}}}∞ buckling control it is possible to increase the maximum bearable load of the active beam-column by 19% for ramp-shaped axial loads and to significantly reduce the beam-column deformations for step-shaped axial loads compared to the passive structure.

Recurrence quantification analysis of extremes of maximum and minimum temperature patterns for different climate scenarios in the Mesochora catchment in Central-Western Greece

Science.gov (United States)

Panagoulia, Dionysia; Vlahogianni, Eleni I.

2018-06-01

A methodological framework based on nonlinear recurrence analysis is proposed to examine the historical data evolution of extremes of maximum and minimum daily mean areal temperature patterns over time under different climate scenarios. The methodology is based on both historical data and atmospheric General Circulation Model (GCM) produced climate scenarios for the periods 1961-2000 and 2061-2100 which correspond to 1 × CO2 and 2 × CO2 scenarios. Historical data were derived from the actual daily observations coupled with atmospheric circulation patterns (CPs). The dynamics of the temperature was reconstructed in the phase-space from the time series of temperatures. The statistically comparing different temperature patterns were based on some discriminating statistics obtained by the Recurrence Quantification Analysis (RQA). Moreover, the bootstrap method of Schinkel et al. (2009) was adopted to calculate the confidence bounds of RQA parameters based on a structural preserving resampling. The overall methodology was implemented to the mountainous Mesochora catchment in Central-Western Greece. The results reveal substantial similarities between the historical maximum and minimum daily mean areal temperature statistical patterns and their confidence bounds, as well as the maximum and minimum temperature patterns in evolution under the 2 × CO2 scenario. A significant variability and non-stationary behaviour characterizes all climate series analyzed. Fundamental differences are produced from the historical and maximum 1 × CO2 scenarios, the maximum 1 × CO2 and minimum 1 × CO2 scenarios, as well as the confidence bounds for the two CO2 scenarios. The 2 × CO2 scenario reflects the strongest shifts in intensity, duration and frequency in temperature patterns. Such transitions can help the scientists and policy makers to understand the effects of extreme temperature changes on water resources, economic development, and health of ecosystems and hence to proceed to

Development and characterization of morin hydrate loaded microemulsion for the management of Alzheimer's disease.

Science.gov (United States)

Sharma, Dheeraj; Singh, Manpreet; Kumar, Punnet; Vikram, Vir; Mishra, Neeraj

2017-12-01

The aim of this study is to prepare and characterize intranasal delivery of morin hydrate loaded microemulsion for the management of Alzheimer's diseases. After intranasal delivery, brain and blood drug concentrations were found to be higher for optimized morin hydrate loaded microemulsion as compared to plain morin hydrate. Significant (P microemulsion as compared to sham control group. Daily chronic treatment with morin loaded microemulsion till the 21st day significantly increased the memory in wistar rats with STZ-induced dementia.

an investigation into the applicability of natural load variation

African Journals Online (AJOL)

Rev. Anoliefo

Keywords – impedance matching,energy yield,natural load variation,maximum power ... Wind speed of 1 m/s and absolute air mass of 1.5 are also ... Unfortunately, solar modules operate under ..... thin-film photovoltaic plants by using physical.

Spatial distribution of the daily rainfall concentration index in Argentina: comparison with other countries

Science.gov (United States)

Llano, María Paula

2017-08-01

The precipitation is a meteorological variable studied in Argentina mainly in annual, seasonal and monthly scales. Its variability is a significant climate element and also a critical socioeconomic factor. This study aims to contribute to the knowledge of daily rainfall in Argentina. Daily records of precipitation for 66 stations provided by the Servicio Meteorológico Nacional are used (period 1991-2014). The spatial distribution of the annual precipitation presents an east-west gradient in the north of the country. In monthly scale, there are different precipitation distributions such as a double maximum in the centre-east zone or a single maximum in the northwest in summer time and in the southern Andes range during the winter. To carry out the study, the concentration index (CI) of daily precipitation with a resolution of 1 mm is used. Precipitation in Argentina, given its vast territory, presents a great variability with a wide range of rainfall regimes; CI values are found between 0.54 and 0.68. These values are categorized as high (greater than 0.61) and low (less than 0.58). The north of the country and the Atlantic coast show the highest CI values. The lower values are present in the Andes range and in the south of the country. The results are compared with other studies in the world.

Effect of Various Interface Thicknesses on the Behaviour of Infilled frame Subjected to Lateral Load

Science.gov (United States)

Senthil, K.; Muthukumar, S.; Rupali, S.; Satyanarayanan, K. S.

2018-03-01

Two dimensional numerical investigations were carried out to study the influence of interface thickness on the behaviour of reinforced concrete frames subjected to in-plane lateral loads using commercial finite element tool SAP 2000. The cement mortar, cork and foam was used as interface material and their effect was studied by varying thicknesses as 6, 8, 10, 14 and 20 mm. The effect of lateral loads on infill masonry wall was also studied by varying arbitrary loads as 10, 20, 40 and 60 kN. The resistance of the frame with cement mortar was found maximum with the interface thickness 10 mm therefore, it is concluded that the maximum influence of interface thickness of 10 mm was found effective. The resistance of integral infill frame with cork and foam interface was found maximum with the interface thickness 6 mm and it is concluded that 6 mm thick interface among the chosen thickness was found effective.

Analysis of Global Sensitivity of Landing Variables on Landing Loads and Extreme Values of the Loads in Carrier-Based Aircrafts

Directory of Open Access Journals (Sweden)

Jin Zhou

2018-01-01

Full Text Available When a carrier-based aircraft is in arrested landing on deck, the impact loads on landing gears and airframe are closely related to landing states. The distribution and extreme values of the landing loads obtained during life-cycle analysis provide an important basis for buffering parameter design and fatigue design. In this paper, the effect of the multivariate distribution was studied based on military standards and guides. By establishment of a virtual prototype, the extended Fourier amplitude sensitivity test (EFAST method is applied on sensitivity analysis of landing variables. The results show that sinking speed and rolling angle are the main influencing factors on the landing gear’s course load and vertical load; sinking speed, rolling angle, and yawing angle are the main influencing factors on the landing gear’s lateral load; and sinking speed is the main influencing factor on the barycenter overload. The extreme values of loads show that the typical condition design in the structural strength analysis is safe. The maximum difference value of the vertical load of the main landing gear is 12.0%. This research may provide some reference for structure design of landing gears and compilation of load spectrum for carrier-based aircrafts.

Organic micropollutants in the Yangtze River: seasonal occurrence and annual loads.

Science.gov (United States)

Qi, Weixiao; Müller, Beat; Pernet-Coudrier, Benoit; Singer, Heinz; Liu, Huijuan; Qu, Jiuhui; Berg, Michael

2014-02-15

Twenty percent of the water run-off from China's land surface drains into the Yangtze River and carries the sewage of approximately 400 million people out to sea. The lower stretch of the Yangtze therefore offers the opportunity to assess the pollutant discharge of a huge population. To establish a comprehensive assessment of micropollutants, river water samples were collected monthly from May 2009 to June 2010 along a cross-section at the lowermost hydrological station of the Yangtze River not influenced by the tide (Datong Station, Anhui province). Following a prescreening of 268 target compounds, we examined the occurrence, seasonal variation, and annual loads of 117 organic micropollutants, including 51 pesticides, 43 pharmaceuticals, 7 household and industrial chemicals, and 16 polycyclic aromatic hydrocarbons (PAHs). During the 14-month study, the maximum concentrations of particulate PAHs (1-5 μg/g), pesticides (11-284 ng/L), pharmaceuticals (5-224 ng/L), and household and industrial chemicals (4-430 ng/L) were generally lower than in other Chinese rivers due to the dilution caused of the Yangtze River's average water discharge of approximately 30,000 m(3)/s. The loads of most pesticides, anti-infectives, and PAHs were higher in the wet season compared to the dry season, which was attributed to the increased agricultural application of chemicals in the summer, an elevated water discharge through the sewer systems and wastewater treatment plants (WWTP) as a result of high hydraulic loads and the related lower treatment efficiency, and seasonally increased deposition from the atmosphere and runoff from the catchment. The estimated annual load of PAHs in the river accounted for some 4% of the total emission of PAHs in the whole Yangtze Basin. Furthermore, by using sucralose as a tracer for domestic wastewater, we estimate a daily disposal of approximately 47 million m(3) of sewage into the river, corresponding to 1.8% of its average hydraulic load. In summary

An investigation of steam-explosion loadings with SIMMER-2

International Nuclear Information System (INIS)

Bohl, W.R.

1990-03-01

The purpose of this work was to provide a reasonable estimate of the maximum loads that might be expected at the upper head of a pressurized water reactor following an in-vessel steam explosion. These loads were determined by parametric cases using a specially modified and calibrated version of the SIMMER-II computer code. Using the determined range of loads, the alpha-mode containment failure probability was to be estimated using engineering judgment. In this context, an alpha-mode failure is defined as resulting from a missile, produced by a steam explosion, and assuming core melt has occurred. 51 refs., 185 figs., 19 tabs

Multiaxial low cycle fatigue life under non-proportional loading

International Nuclear Information System (INIS)

Itoh, Takamoto; Sakane, Masao; Ohsuga, Kazuki

2013-01-01

A simple and clear method of evaluating stress and strain ranges under non-proportional multiaxial loading where principal directions of stress and strain are changed during a cycle is needed for assessing multiaxial fatigue. This paper proposes a simple method of determining the principal stress and strain ranges and the severity of non-proportional loading with defining the rotation angles of the maximum principal stress and strain in a three dimensional stress and strain space. This study also discusses properties of multiaxial low cycle fatigue lives for various materials fatigued under non-proportional loadings and shows an applicability of a parameter proposed by author for multiaxial low cycle fatigue life evaluation

Loads and loads and loads: The influence of prospective load, retrospective load, and ongoing task load in prospective memory

Directory of Open Access Journals (Sweden)

Beat eMeier

2015-06-01

Full Text Available In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load can affect prospective memory performance. The existence of multiple target events increases prospective load and adding complexity to the to-be-remembered action increases retrospective load. In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of prospective load on costs in the ongoing task for categorical targets (Experiment 2, but not for specific targets (Experiment 1. Retrospective load and ongoing task load both affected remembering the retrospective component of the prospective memory task. We suggest that prospective load can enhance costs in the ongoing task due to additional monitoring requirements. Retrospective load and ongoing task load seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially.

40 CFR 130.4 - Water quality monitoring.

Science.gov (United States)

2010-07-01

... QUALITY PLANNING AND MANAGEMENT § 130.4 Water quality monitoring. (a) In accordance with section 106(e)(1...; developing and reviewing water quality standards, total maximum daily loads, wasteload allocations and load... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Water quality monitoring. 130.4...

Pharmacokinetics of and short-term virologic response to low-dose 400-milligram once-daily raltegravir maintenance therapy.

NARCIS (Netherlands)

Ananworanich, J.; Gorowara, M.; Avihingsanon, A.; Kerr, S.J.; Heesch, N. van; Khongpetch, C.; Uanithirat, A.; Hill, A.; Ruxrungtham, K.; Burger, D.M.

2012-01-01

Because studies showed similar viral suppression with lower raltegravir doses and because Asians usually have high antiretroviral concentrations, we explored low-dose raltegravir therapy in Thais. Nineteen adults on raltegravir at 400 mg twice daily (BID) with HIV RNA loads of <50 copies/ml were

Maximum power point tracking controller for PV systems using neural networks

Energy Technology Data Exchange (ETDEWEB)

Bahgat, A.B.G. [Cairo Univ. (Egypt). Faculty of Engineering; Helwa, N.H.; Ahmad, G.E.; El Shenawy, E.T. [National Research Center, Dokki, Cairo (Egypt). Solar Energy Dept.

2005-07-01

This paper presents a development and implementation of a PC-based maximum power point tracker (MPPT) for PV system using neural networks (NN). The system consists of a PV module via a MPPT supplying a dc motor that drives an air fan. The control algorithm is developed to use the artificial NN for detecting the optimal operating point under different operating conditions, then the control action gives the driving signals to the MPPT. A PC is used for data acquisition, running the control algorithm, data storage, as well as data display and analysis. The system has been implemented and tested under various operating conditions. The experimental results showed that the PV system with MPPT always tracks the peak power point of the PV module under various operating conditions. The MPPT transmits about 97% of the actual maximum power generated by the PV module. The MPPT not only increases the power from the PV module to the load, but also maintains longer operating periods for the PV system. The air velocity and the air mass flow rate of the mechanical load are increased considerably, due to the increase of the PV system power. It is also found that the increase in the output energy due to using the MPPT is about 45.2% for a clear sunny day. (Author)

Loading functions for assessment of water pollution from nonpoint sources

International Nuclear Information System (INIS)

McElroy, A.D.; Chiu, S.Y.; Nebgen, J.W.; Aleti, A.; Bennett, F.W.

1976-05-01

Methods for evaluating the quantity of water pollutants generated from nonpoint sources including agriculture, silviculture, construction, mining, runoff from urban areas and rural roads, and terrestrial disposal are developed and compiled for use in water quality planning. The loading functions, plus in some instances emission values, permit calculation of nonpoint source pollutants from available data and information. Natural background was considered to be a source and loading functions were presented to estimate natural or background loads of pollutants. Loading functions/values are presented for average conditions, i.e., annual average loads expressed as metric tons/hectare/year (tons/acre/year). Procedures for estimating seasonal or 30-day maximum and minimum loads are also presented. In addition, a wide variety of required data inputs to loading functions, and delineation of sources of additional information are included in the report. The report also presents an evaluation of limitations and constraints of various methodologies which will enable the user to employ the functions realistically

Daily modes of South Asian summer monsoon variability in the NCEP climate forecast system

Energy Technology Data Exchange (ETDEWEB)

Achuthavarier, Deepthi; Krishnamurthy, V. [George Mason University, Department of Atmospheric, Oceanic and Earth Sciences, Fairfax, VA (United States); Institute of Global Environment and Society, Center for Ocean-Land-Atmosphere Studies, Calverton, MD (United States)

2011-05-15

The leading modes of daily variability of the Indian summer monsoon in the climate forecast system (CFS), a coupled general circulation model, of the National Centers for Environmental Predictions (NCEP) are examined. The space-time structures of the daily modes are obtained by applying multi-channel singular spectrum analysis (MSSA) on the daily anomalies of rainfall. Relations of the daily modes to intraseasonal and interannual variability of the monsoon are investigated. The CFS has three intraseasonal oscillations with periods around 106, 57 and 30 days with a combined variance of 7%. The 106-day mode has spatial structure and propagation features similar to the northeastward propagating 45-day mode in the observations except for its longer period. The 57-day mode, despite being in the same time scale as of the observations has poor eastward propagation. The 30-day mode is northwestward propagating and is similar to its observational counterpart. The 106-day mode is specific to the model and should not be mistaken for a new scale of variability in observations. The dominant interannual signal is related to El Nino-Southern Oscillation (ENSO), and, unlike in the observations, has maximum variance in the eastern equatorial Indian Ocean. Although the Indian Ocean Dipole (IOD) mode was not obtained as a separate mode in the rainfall, the ENSO signal has good correlations with the dipole variability, which, therefore, indicates the dominance of ENSO in the model. The interannual variability is largely determined by the ENSO signal over the regions where it has maximum variance. The interannual variability of the intraseasonal oscillations is smaller in comparison. (orig.)

Seismic Load Rating Procedure for Welded Steel Frames Oligo-cyclic Fatigue

International Nuclear Information System (INIS)

Ratiu, Mircea D.; Moisidis, Nicolae T.

2004-01-01

A dynamic load rating approach for seismic qualification of cold-formed steel welded frames is presented. Allowable seismic loads are developed from cyclic and monotonic tests of standard cold-formed steel components commonly used for piping and electrical raceway supports. The method permits simplified qualification of all connections of frame components through a single load comparison. Test input consists of rotation/cycles-to-failure data and monotonic moment/rotation data. Cyclic data are statistically evaluated to determine an acceptable maximum seismic rotation for the connection. The allowable seismic load is determined from the corresponding static rotation. Application to seismic qualification procedures is discussed. (authors)

Design of a wind turbine rotor for maximum aerodynamic efficiency

DEFF Research Database (Denmark)

Johansen, Jeppe; Aagaard Madsen, Helge; Gaunaa, Mac

2009-01-01

The design of a three-bladed wind turbine rotor is described, where the main focus has been highest possible mechanical power coefficient, CP, at a single operational condition. Structural, as well as off-design, issues are not considered, leading to a purely theoretical design for investigating...... maximum aerodynamic efficiency. The rotor is designed assuming constant induction for most of the blade span, but near the tip region, a constant load is assumed instead. The rotor design is obtained using an actuator disc model, and is subsequently verified using both a free-wake lifting line method...

Short term load forecasting using neuro-fuzzy networks

Energy Technology Data Exchange (ETDEWEB)

Hoffman, M.; Hassan, A. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Martinez, D. [Black Hills Power and Light, Rapid City, SD (United States)

2005-07-01

Details of a neuro-fuzzy network-based short term load forecasting system for power utilities were presented. The fuzzy logic controller was used to fuzzify inputs representing historical temperature and load curves. The fuzzified inputs were then used to develop the fuzzy rules matrix. Output membership function values were determined by evaluating the fuzzified inputs with the fuzzy rules. Output membership function values were used as inputs for the neural network portion of the system. The training process used a back propagation gradient descent algorithm to adjust the weight values of the neural network in order to reduce the error between the neural network output and the desired output. The neural network was then used to predict future load values. Sample data were taken from a local power company's daily load curve to validate the system. A 10 per cent forecast error was introduced in the temperature values to determine the effect on load prediction. Results of the study suggest that the combined use of fuzzy logic and neural networks provide greater accuracy than studies where either approach is used alone. 6 refs., 6 figs.

Ecohydrological modelling of water discharge and nitrate loads in a mesoscale lowland catchment, Germany

Directory of Open Access Journals (Sweden)

N. Fohrer

2009-08-01

Full Text Available The aims of this study are to identify the capacities of applying an ecohydrological model for simulating flow and to assess the impact of point and non-point source pollution on nitrate loads in a complex lowland catchment, which has special hydrological characteristics in comparison with those of other catchments. The study area Kielstau catchment has a size of approximately 50 km² and is located in the North German lowlands. The water quality is not only influenced by the predominating agricultural land use in the catchment as cropland and pasture, but also by six municipal wastewater treatment plants.

Ecohydrological models like the SWAT model (Soil and Water Assessment Tool are useful tools for simulating nutrient loads in river catchments. Diffuse entries from the agriculture resulting from fertilizers as well as punctual entries from the wastewater treatment plants are implemented in the model set-up.

The results of this study show good agreement between simulated and measured daily discharges with a Nash-Sutcliffe efficiency and a correlation coefficient of 0.76 and 0.88 for the calibration period (November 1998 to October 2004; 0.75 and 0.92 for the validation period (November 2004 to December 2007. The model efficiency for daily nitrate loads is 0.64 and 0.5 for the calibration period (June 2005 to May 2007 and the validation period (June 2007 to December 2007, respectively. The study revealed that SWAT performed satisfactorily in simulating daily flow and nitrate loads at the lowland catchment in Northern Germany.

Relationships Between Excessive Heat and Daily Mortality over the Coterminous U.S

Science.gov (United States)

Crosson, William L.; Al-Hamdan, Mohammad Z.; Estes, Maury G., Jr.; Estes, Sue M.; Quattrochi, Dale A.

2015-01-01

In the United States, extreme heat is the most deadly weather-related hazard. In the face of a warming climate and urbanization, it is very likely that extreme heat events (EHEs) will become more common and more severe in the U.S. Using National Land Data Assimilation System (NLDAS) meteorological reanalysis data, we have developed several measures of extreme heat to enable assessments of the impacts of heat on public health over the coterminous U.S. These measures include daily maximum and minimum air temperatures, daily maximum heat indices and a new heat stress variable called Net Daily Heat Stress (NDHS) that gives an integrated measure of heat stress (and relief) over the course of a day. All output has been created on the NLDAS 1/8 degree (approximately 12 km) grid and aggregated to the county level, which is the preferred geographic scale of analysis for public health researchers. County-level statistics have been made available through the Centers for Disease Control and Prevention (CDC) via the Wide-ranging Online Data for Epidemiologic Research (WONDER) system. We have examined the relationship between excessive heat events, as defined in eight different ways from the various daily heat metrics, and heat-related and all-cause mortality defined in CDC's National Center for Health Statistics 'Multiple Causes of Death 1999-2010' dataset. To do this, we linked daily, county-level heat mortality counts with EHE occurrence based on each of the eight EHE definitions by region and nationally for the period 1999-2010. The objectives of this analysis are to determine (1) whether heat-related deaths can be clearly tied to excessive heat events, (2) what time lags are critical for predicting heat-related deaths, and (3) which of the heat metrics correlates best with mortality in each US region. Results show large regional differences in the correlations between heat and mortality. Also, the heat metric that provides the best indicator of mortality varied by region

Local forearm and whole-body respiratory quotient in humans after an oral glucose load

DEFF Research Database (Denmark)

Simonsen, L; Bülow, J; Madsen, J

1993-01-01

the glucose load and had not returned to baseline level at the end of the experiment. Whole-body respiratory quotient (RQ) was, on average, 0.80 (SD 0.05) in the baseline condition and increased to a maximum of 0.91 (0.03) and then decreased to baseline level at the end of the experiment. The local forearm.......17) to 0.63 (0.17) 30 min after the glucose load (P glucose load RQ increased to a maximum level at 0.95 (0.22) and decreased then gradually to baseline level. The experiments emphasize several methodological problems in the measurement of local forearm RQ. The whole-body RQ......The effects of an oral glucose load of 75 g on the local forearm and whole-body energy thermogenesis were measured in normal subjects during the 4 h after the glucose intake. Simultaneous assessment of substrate metabolism in the forearm was performed. Energy expenditure (EE) increased after...

Effects of Food Texture on Three-Dimensional Loads on Implants During Mastication Based on In Vivo Measurements.

Science.gov (United States)

Yoda, Nobuhiro; Ogawa, Toru; Gunji, Yoshinori; Vanegas, Juan R; Kawata, Tetsuo; Sasaki, Keiichi

2016-08-01

The mechanisms by which the loads exerted on implants that support prostheses are modulated during mastication remain unclear. The purpose of this study was to evaluate the effects of food texture on 3-dimensional loads measured at a single implant using a piezoelectric transducer. Two subjects participated in this study. The transducer and the experimental superstructure, which had been adjusted to the subject's occlusal scheme, were attached to the implant with a titanium screw. The foods tested were chewing gum and peanuts. The mean maximum load on the implant in each chewing cycle was significantly higher during peanut chewing than during gum chewing. The direction of maximum load was significantly more widely dispersed during peanut chewing than during gum chewing. The range of changes in load direction during the force-increasing phase of each chewing cycle was significantly wider during peanut chewing than during gum chewing. The load on the implant was affected by food texture in both subjects. This measurement method can be useful to investigate the mechanisms of load modulation on implants during mastication.

Monitoring programme on nitrates in vegetables and vegetable-based baby foods marketed in the Region of Valencia, Spain: levels and estimated daily intake.

Science.gov (United States)

Pardo-Marín, O; Yusà-Pelechà, V; Villalba-Martín, P; Perez-Dasí, J A

2010-04-01

This study was carried out to determine the current levels of nitrates in vegetables and vegetable-based baby foods (a total of 1150 samples) marketed in the Region of Valencia, Spain, over the period 2000-2008, and to estimate the toxicological risk associated with their intake. Average (median) levels of nitrate in lettuce, iceberg-type lettuce and spinach (1156, 798 and 1410 mg kg(-1) w/w, respectively) were lower than the maximum limits established by European Union legislation. Thirteen fresh spinach samples exceeded the regulatory limits. Median nitrate values in other vegetables for which a maximum limit has not been fixed by the European Commission were 196, 203, 1597, 96, 4474 and 2572 mg kg(-1) w/w (for potato, carrot, chard, artichoke, rucola and lamb's lettuce, respectively). The estimated nitrate daily intakes through vegetables consumption for adult, extreme consumers and children were found to be about 29%, 79.8% and 15.1%, respectively, of the acceptable daily intake (3.7 mg kg(-1)). The levels (median = 60.4 mg kg(-1) w/w) found in vegetable-based baby foods were, in all cases, lower the maximum level proposed by European Union legislation. The estimated nitrate daily intake through baby foods for infants between 0-1 and 1-2 years of age were 13% and 18%, respectively, of the acceptable daily intake.

National Assessment Database

Data.gov (United States)

U.S. Environmental Protection Agency — The National Assessment Database stores and tracks state water quality assessment decisions, Total Maximum Daily Loads (TMDLs) and other watershed plans designed to...

Evaluation and projection of daily temperature percentiles from statistical and dynamical downscaling methods

Directory of Open Access Journals (Sweden)

A. Casanueva

2013-08-01

Full Text Available The study of extreme events has become of great interest in recent years due to their direct impact on society. Extremes are usually evaluated by using extreme indicators, based on order statistics on the tail of the probability distribution function (typically percentiles. In this study, we focus on the tail of the distribution of daily maximum and minimum temperatures. For this purpose, we analyse high (95th and low (5th percentiles in daily maximum and minimum temperatures on the Iberian Peninsula, respectively, derived from different downscaling methods (statistical and dynamical. First, we analyse the performance of reanalysis-driven downscaling methods in present climate conditions. The comparison among the different methods is performed in terms of the bias of seasonal percentiles, considering as observations the public gridded data sets E-OBS and Spain02, and obtaining an estimation of both the mean and spatial percentile errors. Secondly, we analyse the increments of future percentile projections under the SRES A1B scenario and compare them with those corresponding to the mean temperature, showing that their relative importance depends on the method, and stressing the need to consider an ensemble of methodologies.

Phosphorus and suspended sediment load estimates for the Lower Boise River, Idaho, 1994-2002

Science.gov (United States)

Donato, Mary M.; MacCoy, Dorene E.

2004-01-01

The U.S. Geological Survey used LOADEST, newly developed load estimation software, to develop regression equations and estimate loads of total phosphorus (TP), dissolved orthophosphorus (OP), and suspended sediment (SS) from January 1994 through September 2002 at four sites on the lower Boise River: Boise River below Diversion Dam near Boise, Boise River at Glenwood Bridge at Boise, Boise River near Middleton, and Boise River near Parma. The objective was to help the Idaho Department of Environmental Quality develop and implement total maximum daily loads (TMDLs) by providing spatial and temporal resolution for phosphorus and sediment loads and enabling load estimates made by mass balance calculations to be refined and validated. Regression models for TP and OP generally were well fit on the basis of regression coefficients of determination (R2), but results varied in quality from site to site. The TP and OP results for Glenwood probably were affected by the upstream wastewater-treatment plant outlet, which provides a variable phosphorus input that is unrelated to river discharge. Regression models for SS generally were statistically well fit. Regression models for Middleton for all constituents, although statistically acceptable, were of limited usefulness because sparse and intermittent discharge data at that site caused many gaps in the resulting estimates. Although the models successfully simulated measured loads under predominant flow conditions, errors in TP and SS estimates at Middleton and in TP estimates at Parma were larger during high- and low-flow conditions. This shortcoming might be improved if additional concentration data for a wider range of flow conditions were available for calibrating the model. The average estimated daily TP load ranged from less than 250 pounds per day (lb/d) at Diversion to nearly 2,200 lb/d at Parma. Estimated TP loads at all four sites displayed cyclical variations coinciding with seasonal fluctuations in discharge

Trends and variability of daily temperature extremes during 1960-2012 in the Yangtze River Basin, China

Science.gov (United States)

The variability of temperature extremes has been the focus of attention during the past few decades, and may exert a great influence on the global hydrologic cycle and energy balance through thermal forcing. Based on daily minimum and maximum temperature observed by the China Meteorological Administ...

Indirect effect of financial strain on daily cortisol output through daily negative to positive affect index in the Coronary Artery Risk Development in Young Adults Study.

Science.gov (United States)

Puterman, Eli; Haritatos, Jana; Adler, Nancy E; Sidney, Steve; Schwartz, Joseph E; Epel, Elissa S

2013-12-01

Daily affect is important to health and has been linked to cortisol. The combination of high negative affect and low positive affect may have a bigger impact on increasing HPA axis activity than either positive or negative affect alone. Financial strain may both dampen positive affect as well as increase negative affect, and thus provides an excellent context for understanding the associations between daily affect and cortisol. Using random effects mixed modeling with maximum likelihood estimation, we examined the relationship between self-reported financial strain and estimated mean daily cortisol level (latent cortisol variable), based on six salivary cortisol assessments throughout the day, and whether this relationship was mediated by greater daily negative to positive affect index measured concurrently in a sample of 776 Coronary Artery Risk Development in Young Adults (CARDIA) Study participants. The analysis revealed that while no total direct effect existed for financial strain on cortisol, there was a significant indirect effect of high negative affect to low positive affect, linking financial strain to elevated cortisol. In this sample, the effects of financial strain on cortisol through either positive affect or negative affect alone were not significant. A combined affect index may be a more sensitive and powerful measure than either negative or positive affect alone, tapping the burden of chronic financial strain, and its effects on biology. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Study of Daily Living Dependency Status among Elderly in an Urban Slum area of Dehradun

Directory of Open Access Journals (Sweden)

Puneet Ohri

2014-12-01

Full Text Available Background: Population aging is observed world-wide. As per Census 2011, elderly constitutes 7.4% population of India. It is expected to increase to 20% in 2050. This segment of population faces multiple medical and psychological problems. To address and solve these problems great effort from the country and the community is required. Objective: To assess the daily living dependency status among elderly. Method:  A cross sectional study was conducted in Dehradun, among 215 elderly people, using a pre-structured questionnaire. Their activities of daily living (ADL and Instrumental activities of daily living (IADL were recorded by observation and interviewing them with their families. Results: Out of total, 93% individuals were independent in their ADLs, with more dependence in the very old elderly. Maximum inability was found in Bathing and dressing. 70.7% elderly were dependent on one or more IADLs, female elderly being more dependent than male (p<0.05. However there was no significant difference of dependence in the male and female elderly in performing ADLs. Education and socio-economic status had a positive effect on independence in IADLs. Among all IADLs male elderly showed a maximum dependency for cooking and laundry while females showed a greater dependency in using telephone, managing money and travelling.

A Study of Daily Living Dependency Status among Elderly in an Urban Slum area of Dehradun

Directory of Open Access Journals (Sweden)

Puneet Ohri

2014-12-01

Full Text Available Background: Population aging is observed world-wide. As per Census 2011, elderly constitutes 7.4% population of India. It is expected to increase to 20% in 2050. This segment of population faces multiple medical and psychological problems. To address and solve these problems great effort from the country and the community is required. Objective: To assess the daily living dependency status among elderly. Method:  A cross sectional study was conducted in Dehradun, among 215 elderly people, using a pre-structured questionnaire. Their activities of daily living (ADL and Instrumental activities of daily living (IADL were recorded by observation and interviewing them with their families. Results: Out of total, 93% individuals were independent in their ADLs, with more dependence in the very old elderly. Maximum inability was found in Bathing and dressing. 70.7% elderly were dependent on one or more IADLs, female elderly being more dependent than male (p<0.05. However there was no significant difference of dependence in the male and female elderly in performing ADLs. Education and socio-economic status had a positive effect on independence in IADLs. Among all IADLs male elderly showed a maximum dependency for cooking and laundry while females showed a greater dependency in using telephone, managing money and travelling.

Forecasting loads and prices in competitive power markets

International Nuclear Information System (INIS)

Bunn, D.W.

2000-01-01

This paper provides a review of some of the main methodological issues and techniques which have become innovative in addressing the problem of forecasting daily loads and prices in the new competitive power markets. Particular emphasis is placed upon computationally intensive methods, including variable segmentation, multiple modeling, combinations, and neural networks for forecasting the demand side, and strategic simulation using artificial agents for the supply side

Two 850 MW turbines on daily cycling, design and operating experience

Energy Technology Data Exchange (ETDEWEB)

Stodieck, W; Straetz, A [Maschinenfabrik Augsburg-Nuernberg (M.A.N.) A.G., Nuernberg (Germany, F.R.)

1979-02-01

When Pennsylvania Power and Light Company (PPandL) of Allentown, U.S.A. signed a contract in 1970 with M.A.N. for the supply of two 850 MW turbines as part of extension of its existing coal-fired power station at Martins Creek by two oil-fired units, continuous base load operation was planned for the initial years. After about ten years both units should have been curbed to low load operation at night and completely shutdown at weekends. Then in 1973 when the oil crisis led to fuel prices which proved the operation of both units uneconomic the way they were planned for the initial years, all conditions were given to operate both turbines on a daily cycling basis from their commissioning day on. This was due to the installation of quality equipment for the improvement of thermal performance.

Rating curve estimation of nutrient loads in Iowa rivers

Science.gov (United States)

Stenback, G.A.; Crumpton, W.G.; Schilling, K.E.; Helmers, M.J.

2011-01-01

Accurate estimation of nutrient loads in rivers and streams is critical for many applications including determination of sources of nutrient loads in watersheds, evaluating long-term trends in loads, and estimating loading to downstream waterbodies. Since in many cases nutrient concentrations are measured on a weekly or monthly frequency, there is a need to estimate concentration and loads during periods when no data is available. The objectives of this study were to: (i) document the performance of a multiple regression model to predict loads of nitrate and total phosphorus (TP) in Iowa rivers and streams; (ii) determine whether there is any systematic bias in the load prediction estimates for nitrate and TP; and (iii) evaluate streamflow and concentration factors that could affect the load prediction efficiency. A commonly cited rating curve regression is utilized to estimate riverine nitrate and TP loads for rivers in Iowa with watershed areas ranging from 17.4 to over 34,600km2. Forty-nine nitrate and 44 TP datasets each comprising 5-22years of approximately weekly to monthly concentrations were examined. Three nitrate data sets had sample collection frequencies averaging about three samples per week. The accuracy and precision of annual and long term riverine load prediction was assessed by direct comparison of rating curve load predictions with observed daily loads. Significant positive bias of annual and long term nitrate loads was detected. Long term rating curve nitrate load predictions exceeded observed loads by 25% or more at 33% of the 49 measurement sites. No bias was found for TP load prediction although 15% of the 44 cases either underestimated or overestimate observed long-term loads by more than 25%. The rating curve was found to poorly characterize nitrate and phosphorus variation in some rivers. ?? 2010 .

Greater Strength Gains after Training with Accentuated Eccentric than Traditional Isoinertial Loads in Already Strength-Trained Men

Science.gov (United States)

Walker, Simon; Blazevich, Anthony J.; Haff, G. Gregory; Tufano, James J.; Newton, Robert U.; Häkkinen, Keijo

2016-01-01

As training experience increases it becomes more challenging to induce further neuromuscular adaptation. Consequently, strength trainers seek alternative training methods in order to further increase strength and muscle mass. One method is to utilize accentuated eccentric loading, which applies a greater external load during the eccentric phase of the lift as compared to the concentric phase. Based upon this practice, the purpose of this study was to determine the effects of 10 weeks of accentuated eccentric loading vs. traditional isoinertial resistance training in strength-trained men. Young (22 ± 3 years, 177 ± 6 cm, 76 ± 10 kg, n = 28) strength-trained men (2.6 ± 2.2 years experience) were allocated to concentric-eccentric resistance training in the form of accentuated eccentric load (eccentric load = concentric load + 40%) or traditional resistance training, while the control group continued their normal unsupervised training program. Both intervention groups performed three sets of 6-RM (session 1) and three sets of 10-RM (session 2) bilateral leg press and unilateral knee extension exercises per week. Maximum force production was measured by unilateral isometric (110° knee angle) and isokinetic (concentric and eccentric 30°.s−1) knee extension tests, and work capacity was measured by a knee extension repetition-to-failure test. Muscle mass was assessed using panoramic ultrasonography and dual-energy x-ray absorptiometry. Surface electromyogram amplitude normalized to maximum M-wave and the twitch interpolation technique were used to examine maximal muscle activation. After training, maximum isometric torque increased significantly more in the accentuated eccentric load group than control (18 ± 10 vs. 1 ± 5%, p < 0.01), which was accompanied by an increase in voluntary activation (3.5 ± 5%, p < 0.05). Isokinetic eccentric torque increased significantly after accentuated eccentric load training only (10 ± 9%, p < 0.05), whereas concentric torque

Effect of Ingredient Loading on Surface Migration Kinetics of Additives in Vulcanized Natural Rubber Compounds

Directory of Open Access Journals (Sweden)

Bryan B. Pajarito

2014-12-01

Full Text Available Surface migration kinetics of chemical additives in vulcanized natural rubber compounds were studied as function of ingredient loading. Rubber sheets were compounded according to a 212-8 fractional factorial design of experiment, where ingredients were treated as factors varied at two levels of loading. Amount of migrated additives in surface of rubber sheets was monitored through time at ambient conditions. The maximum amount and estimated rate of additive migration were determined from weight loss kinetic curves. Attenuated total reflection–Fourier transform infrared (ATR-FTIR spectroscopy and optical microscopy were used to characterize the chemical structure and surface morphology of sheet specimens during additive migration. ANOVA results showed that increased loading of reclaimed rubber, CaCO3, and paraffin wax signif icantly decreased the maximum amount of additive migration; by contrast, increased loading of used oil, asphalt, and mercaptobenzothiazole disulphide (MBTS increased the maximum amount. Increased loading of sulfur, diphenylguanidine (DPG, and paraffin wax significantly decreased the additive migration rate; increased loading of used oil, asphalt, and stearic acid elicited an opposite effect. Comparison of ATRFTIR spectra of migrated and cleaned rubber surfaces showed signif icant variation in intensity of specif ic absorbance bands that are also present in infrared spectra of migrating chemicals. Paraffin wax, used oil, stearic acid, MBTS, asphalt, and zinc stearate were identified to bloom and bleed in the rubber sheets. Optical micrographs of migrated rubber surfaces revealed formation of white precipitates due to blooming and of semi-transparent wet patches due to bleeding.

Research of Charging(Discharging Orderly and Optimizing Load Curve for Electric Vehicles Based on Dynamic Electric Price and V2G

Directory of Open Access Journals (Sweden)

Yang Shuai

2016-01-01

Full Text Available Firstly, using the Monte Carlo method and simulation analysis, this paper builds models for the behaviour of electric vehicles, the conventional charging model and the fast charging model. Secondly, this paper studies the impact that the number of electric vehicles which get access to power grid has on the daily load curve. Then, the paper put forwards a dynamic pricing mechanism of electricity, and studies how this dynamic pricing mechanism guides the electric vehicles to charge orderly. Last but not the least, the paper presents a V2G mechanism. Under this mechanism, electric vehicles can charge orderly and take part in the peak shaving. Research finds that massive electric vehicles’ access to the power grid will increase the peak-valley difference of daily load curve. Dynamic pricing mechanism and V2G mechanism can effectively lead the electric vehicles to take part in peak-shaving, and optimize the daily load curve.

Daily transactional and transformational leadership and daily employee engament

NARCIS (Netherlands)

Breevaart, K.; Bakker, A.B.; Hetland, Jorn; Demerouti, E.; Olsen, O.K.; Espevik, R.

2014-01-01

This diary study adds to the leadership literature by examining the daily influence of transformational leadership, contingent reward, and active management-by-exception (MBE active) on followers' daily work engagement. We compare the unique contribution of these leadership behaviours and focus on

Comparison of 7-day recall and daily diary reports of COPD symptoms and impacts.

Science.gov (United States)

Bennett, Antonia V; Amtmann, Dagmar; Diehr, Paula; Patrick, Donald L

2012-05-01

Patient reporting of symptoms in a questionnaire with a 7-day recall period was expected to differ from symptom reporting in a 7-day symptom diary on the basis of cognitive theory of memory processes and several studies of symptoms and health behaviors. A total of 101 adults with chronic obstructive pulmonary disease (COPD) completed a daily diary of items measuring symptoms and impacts of COPD for 7 days, and on the seventh day they completed a questionnaire of the same items with a 7-day recall period. The analysis examined concordance of 7-day recall with summary descriptors of the daily responses, examined the magnitude and covariates (patient characteristics and response patterns) of the difference between 7-day recall and mean of daily responses, and compared the discriminant ability and ability to detect change of 7-day recall and mean of daily responses. A 7-day recall was moderately concordant with the mean and maximum of daily responses and was 0.34 to 0.50 SDs higher than the mean of daily responses. Only the weekly report itself was a covariate of the difference. The discriminant ability and ability to detect change were equivalent. In measuring the weeklong experience of COPD symptoms and impacts on groups of patients, the 7-day recall scores were higher than the daily diary scores, but equivalent in detecting change over time. Copyright © 2012 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Optimizing Preseason Training Loads in Australian Football.

Science.gov (United States)

Carey, David L; Crow, Justin; Ong, Kok-Leong; Blanch, Peter; Morris, Meg E; Dascombe, Ben J; Crossley, Kay M

2018-02-01

To investigate whether preseason training plans for Australian football can be computer generated using current training-load guidelines to optimize injury-risk reduction and performance improvement. A constrained optimization problem was defined for daily total and sprint distance, using the preseason schedule of an elite Australian football team as a template. Maximizing total training volume and maximizing Banister-model-projected performance were both considered optimization objectives. Cumulative workload and acute:chronic workload-ratio constraints were placed on training programs to reflect current guidelines on relative and absolute training loads for injury-risk reduction. Optimization software was then used to generate preseason training plans. The optimization framework was able to generate training plans that satisfied relative and absolute workload constraints. Increasing the off-season chronic training loads enabled the optimization algorithm to prescribe higher amounts of "safe" training and attain higher projected performance levels. Simulations showed that using a Banister-model objective led to plans that included a taper in training load prior to competition to minimize fatigue and maximize projected performance. In contrast, when the objective was to maximize total training volume, more frequent training was prescribed to accumulate as much load as possible. Feasible training plans that maximize projected performance and satisfy injury-risk constraints can be automatically generated by an optimization problem for Australian football. The optimization methods allow for individualized training-plan design and the ability to adapt to changing training objectives and different training-load metrics.

STRUCTURAL RESPONSE OF THE DIII-D TOROIDAL FIELD COIL TO INCREASED LATERAL LOADS

International Nuclear Information System (INIS)

REIS, E.E; CHIN, E.

2004-03-01

OAK-B135 Recent calibration shots in which full toroidal field (TF) coil current interacted with the maximum poloidal field coils have produced increased lateral loads on the outer sections of the TF-coil. The increased lateral loads have resulted in deflections that have been sufficient to cause the TF-coil to contact adjacent equipment and produce a transient short to ground within the coil. The six outer turns of each TF-coil bundle are clamped together by insulated preloaded studs to provide increased bending stiffness. These sections of the outer bundles depend on friction to react the lateral loads as a bundle rather than six individual turns. A major concern is that the increased loads will produce slip between turns resulting in excessive lateral deflections and possible damage to the insulating sleeve on the preloaded studs. A finite element structural model of the TF-coil was developed for the calculation of deflections and the shear load distribution throughout the coil for the applied lateral loads from a full current calibration shot. The purpose of the updated structural model is to correlate the applied lateral loads to the total shear force between the unbonded sections of the outer turns. An allowable integrated lateral load applied to the outer turns is established based on the maximum shear force that can be reacted by friction. A program that calculates the magnetic fields and integrated lateral load along the outer turns can be incorporated into the plasma control system. The integrated load can then be compared to the calculated allowable value prior to execution of calibration shots. Calibration shots with a calculated total lateral load greater than the allowable value will be prevented

Static load simulation of steering knuckle for a formula student race car

Science.gov (United States)

Saputro, Bagus Aulia; Ubaidillah, Triono, Dicky Agus; Pratama, Dzaky Roja; Cahyono, Sukmaji Indro; Imaduddin, Fitrian

2018-02-01

This research aims to determine the stress distribution which occurs on the steering knuckle and to define its safety factor number. Steering knuckle is the most critical part of a car's steering system. Steering knuckle supports the tie rod, brake caliper, and the wheels to provide stability. Steering knuckle withstands the load which given on the front wheels and functions as the wheel's axis. Balljoint and king support the rotation of the suspension arm. When the car is in idle position, knuckle hold the weight of the car, it gets braking force when it's braking and cornering. Knuckle is designed to have the strength that could withstand load and to have a good safety factor value. Knuckle is designed using Fusion software then simulated using Fusion simulation software with a static load, moment braking force, and cornering force as the loads in this simulation. The simulation works in ideal condition. The result of this simulation is satisfying. This simulation produces a maximum displacement of 0.01281mm, the maximum shear stress is 3.707 MPa on the stub hole, and the safety factor is 5.24. The material used for this product is mild steel AISI 1018.

EPA Office of Water (OW): Impaired Waters with TMDLs NHDPlus Indexed Dataset

Data.gov (United States)

U.S. Environmental Protection Agency — The Total Maximum Daily Load (TMDL) Tracking System contains information on waters that are Not Supporting their designated uses. These waters are listed by the...

Lake Tahoe Water Quality Improvement Programs

Science.gov (United States)

Information on the Lake Tahoe watershed, EPA's protection efforts, water quality issues, effects of climate, change, Lake Tahoe Total Maximum Daily Load (TMDL), EPA-sponsored projects, and list of partner agencies.

EPA Office of Water (OW): TMDLs on Impaired Waters NHDPlus Indexed Dataset

Data.gov (United States)

U.S. Environmental Protection Agency — The Total Maximum Daily Load (TMDL) Tracking System contains information on waters that are Not Supporting their designated uses. These waters are listed by the...

Pre-slaughter sound levels and pre-slaughter handling from loading at the farm till slaughter influence pork quality.

Science.gov (United States)

Vermeulen, L; Van de Perre, V; Permentier, L; De Bie, S; Verbeke, G; Geers, R

2016-06-01

This study investigates the relationship between sound levels, pre-slaughter handling during loading and pork quality. Pre-slaughter variables were investigated from loading till slaughter. A total of 3213 pigs were measured 30 min post-mortem for pH(30LT) (M. Longissimus thoracis). First, a sound level model for the risk to develop PSE meat was established. The difference in maximum and mean sound level during loading, mean sound level during lairage and mean sound level prior to stunning remained significant within the model. This indicated that sound levels during loading had a significant added value to former sound models. Moreover, this study completed the global classification checklist (Vermeulen et al., 2015a) by developing a linear mixed model for pH(30LT) and PSE prevalence, with the difference in maximum and mean sound level measured during loading, the feed withdrawal period and the difference in temperature during loading and lairage. Hence, this study provided new insights over previous research where loading procedures were not included. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fracture load of complete-arch implant-supported prostheses reinforced with nylon-silica mesh: An in vitro study.

Science.gov (United States)

Gonçalves, Fernanda de Cássia Papaiz; Amaral, Marina; Borges, Alexandre Luiz Souto; Gonçalves, Luiz Fernando Martins; Paes-Junior, Tarcisio José de Arruda

2018-04-01

Complete-arch implant-supported prostheses without a framework have a high risk of failure: a straightforward and inexpensive reinforcement material, such as nylon mesh, could improve their longevity. The purpose of this in vitro study was to evaluate a nylon-silica mesh compound on the fracture strength of acrylic resin and the fracture load of complete-arch implant-supported prostheses. Twenty-four complete mandibular arch implant-supported prostheses were divided into 2 groups according to cantilever length (molar and premolar) and subdivided into another 2 subgroups according to the presence or absence of reinforcing mesh. The specimens were submitted to a maximum load-to-fracture test in a universal testing machine, with a 100-N load cell, a 2 mm/min crosshead speed, and a spherical metal tip diameter of 4 mm at different points (molar and premolar). These were submitted to 1-way analysis of variance for repeated measurement and the post hoc Tukey multiple comparison test (α=.05). The mean maximum load ±standard deviation for the molar group was 393.4 ±95.0 N with reinforcement and 305.4 ±76.3 N without reinforcement (P=.02); and for the premolar group was 1083.3 ±283.7 N with reinforcement and 605.3 ±90.5 N without reinforcement (P=.001). Reinforcement with nylon mesh increased the mean maximum load of implant-supported complete-arch prostheses at both cantilever lengths. The cantilever to the premolar (5 mm) presented the highest maximum load values to fracture. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

EXTREME MAXIMUM AND MINIMUM AIR TEMPERATURE IN MEDİTERRANEAN COASTS IN TURKEY

Directory of Open Access Journals (Sweden)

Barbaros Gönençgil

2016-01-01

Full Text Available In this study, we determined extreme maximum and minimum temperatures in both summer and winter seasons at the stations in the Mediterranean coastal areas of Turkey.In the study, the data of 24 meteorological stations for the daily maximum and minimumtemperatures of the period from 1970–2010 were used. From this database, a set of four extreme temperature indices applied warm (TX90 and cold (TN10 days and warm spells (WSDI and cold spell duration (CSDI. The threshold values were calculated for each station to determine the temperatures that were above and below the seasonal norms in winter and summer. The TX90 index displays a positive statistically significant trend, while TN10 display negative nonsignificant trend. The occurrence of warm spells shows statistically significant increasing trend while the cold spells shows significantly decreasing trend over the Mediterranean coastline in Turkey.

Loading intensity prediction by velocity and the OMNI-RES 0–10 scale in bench press

OpenAIRE

Naclerio, Fernando; Larumbe-Zabala, Eneko

2017-01-01

This study examined the possibility of using movement velocity and the perceived exertion as indicators of relative load in the bench press exercise. Three hundred eight young, healthy, resistance trained athletes (242 male and 66 female) performed a progressive strength test up to the one-repetition maximum for the individual determination of the full load-velocity and load-exertion relationships. Longitudinal regression models were used to predict the relative load from the average velocity...

Characteristics of sub-daily precipitation extremes in observed data and regional climate model simulations

Science.gov (United States)

Beranová, Romana; Kyselý, Jan; Hanel, Martin

2018-04-01

The study compares characteristics of observed sub-daily precipitation extremes in the Czech Republic with those simulated by Hadley Centre Regional Model version 3 (HadRM3) and Rossby Centre Regional Atmospheric Model version 4 (RCA4) regional climate models (RCMs) driven by reanalyses and examines diurnal cycles of hourly precipitation and their dependence on intensity and surface temperature. The observed warm-season (May-September) maxima of short-duration (1, 2 and 3 h) amounts show one diurnal peak in the afternoon, which is simulated reasonably well by RCA4, although the peak occurs too early in the model. HadRM3 provides an unrealistic diurnal cycle with a nighttime peak and an afternoon minimum coinciding with the observed maximum for all three ensemble members, which suggests that convection is not captured realistically. Distorted relationships of the diurnal cycles of hourly precipitation to daily maximum temperature in HadRM3 further evidence that underlying physical mechanisms are misrepresented in this RCM. Goodness-of-fit tests indicate that generalised extreme value distribution is an applicable model for both observed and RCM-simulated precipitation maxima. However, the RCMs are not able to capture the range of the shape parameter estimates of distributions of short-duration precipitation maxima realistically, leading to either too many (nearly all for HadRM3) or too few (RCA4) grid boxes in which the shape parameter corresponds to a heavy tail. This means that the distributions of maxima of sub-daily amounts are distorted in the RCM-simulated data and do not match reality well. Therefore, projected changes of sub-daily precipitation extremes in climate change scenarios based on RCMs not resolving convection need to be interpreted with caution.

Approximate maximum parsimony and ancestral maximum likelihood.

Science.gov (United States)

Alon, Noga; Chor, Benny; Pardi, Fabio; Rapoport, Anat

2010-01-01

We explore the maximum parsimony (MP) and ancestral maximum likelihood (AML) criteria in phylogenetic tree reconstruction. Both problems are NP-hard, so we seek approximate solutions. We formulate the two problems as Steiner tree problems under appropriate distances. The gist of our approach is the succinct characterization of Steiner trees for a small number of leaves for the two distances. This enables the use of known Steiner tree approximation algorithms. The approach leads to a 16/9 approximation ratio for AML and asymptotically to a 1.55 approximation ratio for MP.

Artificial Intelligence Techniques for Predicting and Mapping Daily Pan Evaporation

Science.gov (United States)

Arunkumar, R.; Jothiprakash, V.; Sharma, Kirty

2017-09-01

In this study, Artificial Intelligence techniques such as Artificial Neural Network (ANN), Model Tree (MT) and Genetic Programming (GP) are used to develop daily pan evaporation time-series (TS) prediction and cause-effect (CE) mapping models. Ten years of observed daily meteorological data such as maximum temperature, minimum temperature, relative humidity, sunshine hours, dew point temperature and pan evaporation are used for developing the models. For each technique, several models are developed by changing the number of inputs and other model parameters. The performance of each model is evaluated using standard statistical measures such as Mean Square Error, Mean Absolute Error, Normalized Mean Square Error and correlation coefficient (R). The results showed that daily TS-GP (4) model predicted better with a correlation coefficient of 0.959 than other TS models. Among various CE models, CE-ANN (6-10-1) resulted better than MT and GP models with a correlation coefficient of 0.881. Because of the complex non-linear inter-relationship among various meteorological variables, CE mapping models could not achieve the performance of TS models. From this study, it was found that GP performs better for recognizing single pattern (time series modelling), whereas ANN is better for modelling multiple patterns (cause-effect modelling) in the data.

Crack path in aeronautical titanium alloy under ultrasonic torsion loading

Directory of Open Access Journals (Sweden)

A. Nikitin

2016-01-01

Full Text Available This paper discusses features of fatigue crack initiation and growth in aeronautical VT3-1 titanium alloy under pure torsion loading in gigacycle regime. Two materials: extruded and forged VT3-1 titanium alloys were studied. Torsion fatigue tests were performed up to fatigue life of 109 cycles. The results of the torsion tests were compared with previously obtained results under fully reversed axial loading on the same alloys. It has been shown that independently on production process as surface as well subsurface crack initiation may appear under ultrasonic torsion loading despite the maximum stress amplitude located at the specimen surface. In the case of surface crack initiation, a scenario of crack initiation and growth is similar to HCF regime except an additional possibility for internal crack branching. In the case of subsurface crack, the initiation site is located below the specimen surface (about 200 μm and is not clearly related to any material flaw. Internal crack initiation is produced by shear stress in maximum shear plane and early crack growth is in Mode II. Crack branching is limited in the case of internal crack initiation compared to surface one. A typical ‘fish-eye’ crack can be observed at the torsion fracture surface, but mechanism of crack initiation seems not to be the same than under axial fatigue loading.

Two-Stage Chaos Optimization Search Application in Maximum Power Point Tracking of PV Array

Directory of Open Access Journals (Sweden)

Lihua Wang

2014-01-01

Full Text Available In order to deliver the maximum available power to the load under the condition of varying solar irradiation and environment temperature, maximum power point tracking (MPPT technologies have been used widely in PV systems. Among all the MPPT schemes, the chaos method is one of the hot topics in recent years. In this paper, a novel two-stage chaos optimization method is presented which can make search faster and more effective. In the process of proposed chaos search, the improved logistic mapping with the better ergodic is used as the first carrier process. After finding the current optimal solution in a certain guarantee, the power function carrier as the secondary carrier process is used to reduce the search space of optimized variables and eventually find the maximum power point. Comparing with the traditional chaos search method, the proposed method can track the change quickly and accurately and also has better optimization results. The proposed method provides a new efficient way to track the maximum power point of PV array.

Impact of onsite solar generation on system load demand forecast

International Nuclear Information System (INIS)

Kaur, Amanpreet; Pedro, Hugo T.C.; Coimbra, Carlos F.M.

2013-01-01

Highlights: • We showed the impact onsite solar generation on system demand load forecast. • Forecast performance degrades by 9% and 3% for 1 h and 15 min forecast horizons. • Error distribution for onsite case is best characterized as t-distribution. • Relation between error, solar penetration and solar variability is characterized. - Abstract: Net energy metering tariffs have encouraged the growth of solar PV in the distribution grid. The additional variability associated with weather-dependent renewable energy creates new challenges for power system operators that must maintain and operate ancillary services to balance the grid. To deal with these issues power operators mostly rely on demand load forecasts. Electric load forecast has been used in power industry for a long time and there are several well established load forecasting models. But the performance of these models for future scenario of high renewable energy penetration is unclear. In this work, the impact of onsite solar power generation on the demand load forecast is analyzed for a community that meets between 10% and 15% of its annual power demand and 3–54% of its daily power demand from a solar power plant. Short-Term Load Forecasts (STLF) using persistence, machine learning and regression-based forecasting models are presented for two cases: (1) high solar penetration and (2) no penetration. Results show that for 1-h and 15-min forecasts the accuracy of the models drops by 9% and 3% with high solar penetration. Statistical analysis of the forecast errors demonstrate that the error distribution is best characterized as a t-distribution for the high penetration scenario. Analysis of the error distribution as a function of daily solar penetration for different levels of variability revealed that the solar power variability drives the forecast error magnitude whereas increasing penetration level has a much smaller contribution. This work concludes that the demand forecast error distribution

Mechanical loading of the gymnast’s motor system during swings on rings

Directory of Open Access Journals (Sweden)

R Serafin

2008-12-01

Full Text Available The aim of this work was to identify the mechanical loading of the gymnast’s motor system during forward and backward swings on gymnastic rings. A junior gymnast of the First Class, aged 14, with body mass 53.1 kg and body length 1.61 m, participated in the study. He executed a series of ten cyclic swing movements on rings with his maximum amplitude. Kinematic variables of the gymnast’s centre of mass (COM as well as reaction forces in the cables were measured and synchronized using the SIMI MOTION movement analysis system. Two separate phases of mechanical loading of the motor system have been identified: resistance phase and non resistance phase. In the non resistance phase the gymnast attains similar values of the COM’s momentum but different angular displacements. In the resistance phase the forces acting on the motor system have their maximum. They amount to 5.5 BW for the forward swing and 6.5 BW for the backward swing movement. The maximum rate of change of the force for forward and backward swing is 42.6 BWs-1 and 67.4 BWs-1, respectively. These two variables differentiate the mechanical loading of the gymnast’s motor system between forward and backward swings. The reaction force produced by the gymnast is significantly greater during the execution of forward swings. It seems probable that horizontal displacements of COM may be the factor responsible for reduction of the mechanical loading experienced by the gymnast.

Residual Strength of In-plane Loaded Debonded Sandwich Panels

DEFF Research Database (Denmark)

Berggreen, Carl Christian; Simonsen, Bo Cerup

2005-01-01

This paper presents a FEM based numerical model for prediction of residual strength of damaged sandwich panels. As demonstrated, the model can predict the maximum load carrying capacity of real-life panels with debond damages, where the failure is governed by face-sheet buckling followed by debond...

Tritium surface loading due to contamination of rainwater from atmospheric release at NAPS (2011)

International Nuclear Information System (INIS)

Gautam, Y.P.; Sharma, Saivajay; Rao, K.S.; Singh, Bhikam; Kumar, Avinash; Ravi, P.M.

2012-01-01

Annual tritium (HTO) surface loading has been measured and calculated for the year 2011 within 0.8 km distance from 145 m high stack of Narora Atomic Power Station (NAPS) at eight locations in different directions. The technique for measured values consists of the summation of product of tritium concentration (Bq/l) in daily rainfall samples and daily rainfall (mm). Tritium surface loading studies at NAPS reveal that a fraction 1.01E-03 of total annual tritium released through stack gets deposited on the surface due to washout/rainout of plume within 0.8 km radial distance from stack. The range of deposition velocity, Vw (m.s -1 ) i.e., the ratio of annual tritium surface loading W (Bq. m -2 .s -1 ) and annual mean tritium concentration in air, c 0 (Bq.m -3 ) at three locations for the years 2011 is found to be 6.12E-04 to 2.89E-03. The average value for wet deposition velocity V w for NAPS site is estimated as 3.17E-03 m.s -1 . (author)

Daily mini quizzes as means for improving student performance in anatomy course.

Science.gov (United States)

Poljicanin, Ana; Carić, Ana; Vilović, Katarina; Kosta, Vana; Marinović Guić, Maja; Aljinović, Jure; Grković, Ivica

2009-02-01

To evaluate daily-written 10-question quizzes in a medical anatomy course as a way to integrate assessment into the course and to evaluate their effect on the course success. Students answering correctly 8/10 or more questions were awarded 0.5 points per quiz. There were 34 quizzes with a maximum point score 17. Measurable outcomes of academic progress in anatomy course (pass rates on 4 examination terms, total pass rate, and average marks) were calculated, and 2007/08 academic year was compared with the previous academic year in which daily written quizzes were not a part of the course. The relationship between cumulative points on daily quizzes and 3 components of the final examination (written, practical, and oral) for 2007/08 academic year was assessed by non-parametric correlation testing. Individual scores on quizzes ranged from 1.5 to 13.5 points. There was a positive correlation between scores on quizzes and grades on 3 components of the final examination: written (Spearman rho=0.784, Pstudents in the previous academic year, students attending the course with daily quizzes significantly improved their academic achievement, expressed as the pass rate at the first examination term (39% vs 62%, respectively, chi(2) test, P=0.006, ) and the average course grade (2.71+/-1.08 vs 3.38+/-1.26, respectively; t test, P<0.001). Despite their frequency and possible associated stress, daily quizzes were associated with better academic success in the anatomy course.

Experimental Study on Mechanical and Acoustic Emission Characteristics of Rock-Like Material Under Non-uniformly Distributed Loads

Science.gov (United States)

Wang, Xiao; Wen, Zhijie; Jiang, Yujing; Huang, Hao

2018-03-01

The mechanical and acoustic emission characteristics of rock-like materials under non-uniform loads were investigated by means of a self-developed mining-induced stress testing system and acoustic emission monitoring system. In the experiments, the specimens were divided into three regions and different initial vertical stresses and stress loading rates were used to simulate different mining conditions. The mechanical and acoustic emission characteristics between regions were compared, and the effects of different initial vertical stresses and different stress loading rates were analysed. The results showed that the mechanical properties and acoustic emission characteristics of rock-like materials can be notably localized. When the initial vertical stress and stress loading rate are fixed, the peak strength of region B is approximately two times that of region A, and the maximum acoustic emission hit value of region A is approximately 1-2 times that of region B. The effects of the initial vertical stress and stress loading rate on the peck strain, maximum hit value, and occurrence time of the maximum hit are similar in that when either of the former increase, the latter all decrease. However, peck strength will increase with the increase in loading rate and decrease with the increase in initial vertical stress. The acoustic emission hits can be used to analyse the damage in rock material, but the number of acoustic emission hits cannot be used alone to determine the degree of rock damage directly.

Short-term residential load forecasting: Impact of calendar effects and forecast granularity

DEFF Research Database (Denmark)

Lusis, Peter; Khalilpour, Kaveh Rajab; Andrew, Lachlan

2017-01-01

forecasting for a single-customer or even down at an appliance level. Access to high resolution data from smart meters has enabled the research community to assess conventional load forecasting techniques and develop new forecasting strategies suitable for demand-side disaggregated loads. This paper studies...... how calendar effects, forecasting granularity and the length of the training set affect the accuracy of a day-ahead load forecast for residential customers. Root mean square error (RMSE) and normalized RMSE were used as forecast error metrics. Regression trees, neural networks, and support vector...... regression yielded similar average RMSE results, but statistical analysis showed that regression trees technique is significantly better. The use of historical load profiles with daily and weekly seasonality, combined with weather data, leaves the explicit calendar effects a very low predictive power...

Implementation to spanish protocol of quality control of accelerators to daily control of electron beams

International Nuclear Information System (INIS)

Adaimi Hernandez, P.; Ramirez Ros, J. C.; Casa de Julian, M. A. de la; Clemente Gutierrez, F.; Cabello Murillo, E.; Diaz Fuente, R.; Ferrando Sanchez, A.

2011-01-01

A revised procedure for daily control of the electron beams to make measurements more meaningful physically, having a better reproducibility and more in line with the recommendations of the Spanish Protocol for Quality Control in Electron Linear Accelerators Clinical Use. The daily quality control beams of high energy electrons that had been done so far was the finding that the record of a series of measures (symmetry, uniformity, stability, energy, beam central dose) were within tolerance values established. The amendment is to check the beam quality by directly measuring changes in absorption depth at which the dose is reduced to half its maximum value, R50.

Influence of boiler load on water tubes burnout

Energy Technology Data Exchange (ETDEWEB)

Said, S.A.M.; Habib, M.A.; Badr, H.M.; Mansour, R. [King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia). Dept. of Mechanical Engineering

2009-07-01

The influence of boiler loads on water tube burnout was investigated. The in-service boiler had 2 burners at different levels located in the front of the burner's wall. Homogenous-flow and separated-flow models were designed to simulate the water circulation and combustion processes inside the boiler tubes. Heat flux calculations were derived by solving the conservation of mass, momentum, and energy equations and species concentration as well as by solving turbulence, reaction rate, and radiation model equations. Results of the study showed that heat flux during full loads ranged from close to 0 to 270 kW/m2. The right side screen wall of the burner exhibited higher heat flux values in the middle region of the wall where large areas were subjected to heat flux close to a maximum of 270 kW/m2. Results also included reductions in heat flux values at partial loads. Maximum values were reduced from 270 kW/m2 ato 230 kW/m2 at 75 per cent capacity and 200 kW/m2 at 60 per cent capacity. The rate of steam generation increased from 0.1 kg/s to 0.153 kg/s when the distance from the burner wall increased from 2 meters to 12 meters. 10 refs., 10 figs.

Assessment of daily-life dynamic interactions between human body and environment using movement and force sensing on the interface

NARCIS (Netherlands)

Kortier, H.G.; Veltink, Petrus H.

2011-01-01

This study describes a method to estimate load dynamics during the execution of daily life tasks. In many motor tasks, the central nervous system (CNS) applies feed-forward control, using learned patterns. The contribution of state feedback (visual/proprioceptive/reflexive) is significantly less

Ocular pharmacokinetics and tolerability of bimatoprost ophthalmic solutions administered once or twice daily in rabbits, and clinical dosing implications

Science.gov (United States)

Shen, Jie; Goodkin, Margot L; Tong, Warren; Attar, Mayssa

2017-01-01

Purpose Fixed-combination medications can benefit patients requiring multiple agents to lower their intraocular pressure (IOP), but combining agents with complementary mechanisms of action is challenging if their dosing frequency differs. This study compares in vivo pharmacokinetic and ocular tolerability of bimatoprost 0.01% ophthalmic solutions dosed once or twice daily. Reports of twice-daily dosing in glaucoma patients are also reviewed. Methods New Zealand White rabbits were administered bimatoprost 0.01% monotherapy or fixed-combination bimatoprost 0.01%/brimonidine 0.1%, once or twice daily in both eyes for 4 days. Ocular tissues were harvested and analyzed by liquid chromatography-tandem mass spectrometry. The pharmacokinetic parameters calculated included maximum observed concentration, time to maximum concentration, and area under the concentration-time curve. Results Due to extensive metabolism, bimatoprost concentration was below the quantitation limit by 1 hour post-dose in all samples. Bimatoprost acid exposure, however, could be measured up to 6–8 hours post-dose and was similar in the aqueous humor and iris-ciliary body (pharmacological site of action) of animals treated once or twice daily with either bimatoprost 0.01% or fixed-combination bimatoprost 0.01%/brimonidine 0.1%. Increasing dosage frequency in rabbits did not raise the incidence of drug-related conjunctival hyperemia (most common adverse event associated with bimatoprost use in humans), suggesting comparable ocular tolerability of the once- and twice-daily regimens for each formulation. Conclusion Bimatoprost 0.01% administered once or twice daily as monotherapy and in fixed-combination with brimonidine 0.1% in rabbits show similar pharmacokinetic profiles of bimatoprost acid, especially in the iris-ciliary body. Key findings from previous clinical studies suggest that by varying the concentration of benzalkonium chloride (a preservative with corneal penetration-enhancing properties

A pattern recognition methodology for evaluation of load profiles and typical days of large electricity customers

International Nuclear Information System (INIS)

Tsekouras, G.J.; Kotoulas, P.B.; Tsirekis, C.D.; Dialynas, E.N.; Hatziargyriou, N.D.

2008-01-01

This paper describes a pattern recognition methodology for the classification of the daily chronological load curves of each large electricity customer, in order to estimate his typical days and his respective representative daily load profiles. It is based on pattern recognition methods, such as k-means, self-organized maps (SOM), fuzzy k-means and hierarchical clustering, which are theoretically described and properly adapted. The parameters of each clustering method are properly selected by an optimization process, which is separately applied for each one of six adequacy measures. The results can be used for the short-term and mid-term load forecasting of each consumer, for the choice of the proper tariffs and the feasibility studies of demand side management programs. This methodology is analytically applied for one medium voltage industrial customer and synoptically for a set of medium voltage customers of the Greek power system. The results of the clustering methods are presented and discussed. (author)

Chronic daily headaches

Directory of Open Access Journals (Sweden)

Fayyaz Ahmed

2012-01-01

Full Text Available Chronic Daily Headache is a descriptive term that includes disorders with headaches on more days than not and affects 4% of the general population. The condition has a debilitating effect on individuals and society through direct cost to healthcare and indirectly to the economy in general. To successfully manage chronic daily headache syndromes it is important to exclude secondary causes with comprehensive history and relevant investigations; identify risk factors that predict its development and recognise its sub-types to appropriately manage the condition. Chronic migraine, chronic tension-type headache, new daily persistent headache and medication overuse headache accounts for the vast majority of chronic daily headaches. The scope of this article is to review the primary headache disorders. Secondary headaches are not discussed except medication overuse headache that often accompanies primary headache disorders. The article critically reviews the literature on the current understanding of daily headache disorders focusing in particular on recent developments in the treatment of frequent headaches.

Buckling of thin-walled beams under concentrated transverse loading

NARCIS (Netherlands)

Menken, C.M.; Erp, van G.M.; Krupta, V.; Drdacky, M.

1991-01-01

The transversely loaded thin-walled beam under a non-uniform bending moment forms an example of the detrimental influence that a local effect may have on the overall behaviour. The local effect is the plate buckling in the region of maximum bending moment. The overall behaviour is the

The prediction of the impact of climatic factors on short-term electric power load based on the big data of smart city

Science.gov (United States)

Qiu, Yunfei; Li, Xizhong; Zheng, Wei; Hu, Qinghe; Wei, Zhanmeng; Yue, Yaqin

2017-08-01

The climate changes have great impact on the residents’ electricity consumption, so the study on the impact of climatic factors on electric power load is of significance. In this paper, the effects of the data of temperature, rainfall and wind of smart city on short-term power load is studied to predict power load. The authors studied the relation between power load and daily temperature, rainfall and wind in the 31 days of January of one year. In the research, the authors used the Matlab neural network toolbox to establish the combinational forecasting model. The authors trained the original input data continuously to get the internal rules inside the data and used the rules to predict the daily power load in the next January. The prediction method relies on the accuracy of weather forecasting. If the weather forecasting is different from the actual weather, we need to correct the climatic factors to ensure accurate prediction.

Environmental Monitoring, Water Quality - TMDL Lakes

Data.gov (United States)

NSGIC Education | GIS Inventory — The Clean Water Act Section 303(d) establishes the Total Maximum Daily Load (TMDL) program. The purpose of the TMDL program is to identify sources of pollution and...

Value-Focused Approach to Improving Water Quality: Albany-Millersburg Talking Water Gardens

Science.gov (United States)

To meet new total maximum daily load requirements, the cities of Albany and Millersburg in Oregon worked together to design and fund a project that addresses wastewater treatment from a natural hydrological perspective.

Heuristics for container loading of furniture

DEFF Research Database (Denmark)

Egeblad, Jens; Garavelli, Claudio; Lisi, Stefano

2010-01-01

. In the studied company, the problem arises hundreds of times daily during transport planning. Instances may contain more than one hundred different items with irregular shapes. To solve this complex problem we apply a set of heuristics successively that each solve one part of the problem. Large items...... are combined in specific structures to ensure proper protection of the items during transportation and to simplify the problem. The solutions generated by the heuristic has an average loading utilization of 91.3% for the most general instances with average running times around 100 seconds....

Optimizing electrical load pattern in Kuwait using grid connected photovoltaic systems

International Nuclear Information System (INIS)

Al-Hasan, A.Y.; Ghoneim, A.A.; Abdullah, A.H.

2004-01-01

Grid connected photovoltaic systems is one of the most promising applications of photovoltaic systems. These systems are employed in applications where utility service is already available. In this case, there is no need for battery storage because grid power may be used to supplement photovoltaic systems (PV) when the load exceeds available PV generation. The load receives electricity from both the photovoltaic array and the utility grid. In this system, the load is the total electrical energy consumption. The main objective of the present work is to optimize the electrical load pattern in Kuwait using grid connected PV systems. In this situation, the electric load demand can be satisfied from both the photovoltaic array and the utility grid. The performance of grid connected photovoltaic systems in the Kuwait climate has been evaluated. It was found that the peak load matches the maximum incident solar radiation in Kuwait, which would emphasize the role of using the PV station to minimize the electrical load demand. In addition, a significant reduction in peak load can be achieved with grid connected PV systems

Ochratoxin A in Danish cereals 1986-1992 and daily intake by the Danish population

DEFF Research Database (Denmark)

Jørgensen, Kevin; Rasmussen, Gitte; Thorup, Inger

1996-01-01

Ochratoxin A is a common contaminant in Danish cereals, and surveillance of ochratoxin A in cereals has been a part of the Danish monitoring system since 1986. Occurrence of ochratoxin A is highly related to the climatic conditions during harvest. Rye is the crop which is most often contaminated...... and contains the highest levels of ochratoxin A. The result of the survey period from 1986 to 1992 (total of 1431 samples) together with food consumption data is the basis of intake calculations. Especially in years with wet weather during harvest, the daily intake of ochratoxin A for some individuals...... in the Danish population could reach levels which exceed the tolerable daily intake (TDI) for ochratoxin A of 5 ng/kg bw suggested by The Nordic Working Group on Food Toxicology and Risk Evaluation. A maximum limit of 5 mu g ochratoxin A per kg cereal would keep the daily intake below 5 ng/kg bw....

Short-Term Power Load Point Prediction Based on the Sharp Degree and Chaotic RBF Neural Network

Directory of Open Access Journals (Sweden)

Dongxiao Niu

2015-01-01

Full Text Available In order to realize the predicting and positioning of short-term load inflection point, this paper made reference to related research in the field of computer image recognition. It got a load sharp degree sequence by the transformation of the original load sequence based on the algorithm of sharp degree. Then this paper designed a forecasting model based on the chaos theory and RBF neural network. It predicted the load sharp degree sequence based on the forecasting model to realize the positioning of short-term load inflection point. Finally, in the empirical example analysis, this paper predicted the daily load point of a region using the actual load data of the certain region to verify the effectiveness and applicability of this method. Prediction results showed that most of the test sample load points could be accurately predicted.

Modelling non-stationary annual maximum flood heights in the lower Limpopo River basin of Mozambique

Directory of Open Access Journals (Sweden)

Daniel Maposa

2016-05-01

Full Text Available In this article we fit a time-dependent generalised extreme value (GEV distribution to annual maximum flood heights at three sites: Chokwe, Sicacate and Combomune in the lower Limpopo River basin of Mozambique. A GEV distribution is fitted to six annual maximum time series models at each site, namely: annual daily maximum (AM1, annual 2-day maximum (AM2, annual 5-day maximum (AM5, annual 7-day maximum (AM7, annual 10-day maximum (AM10 and annual 30-day maximum (AM30. Non-stationary time-dependent GEV models with a linear trend in location and scale parameters are considered in this study. The results show lack of sufficient evidence to indicate a linear trend in the location parameter at all three sites. On the other hand, the findings in this study reveal strong evidence of the existence of a linear trend in the scale parameter at Combomune and Sicacate, whilst the scale parameter had no significant linear trend at Chokwe. Further investigation in this study also reveals that the location parameter at Sicacate can be modelled by a nonlinear quadratic trend; however, the complexity of the overall model is not worthwhile in fit over a time-homogeneous model. This study shows the importance of extending the time-homogeneous GEV model to incorporate climate change factors such as trend in the lower Limpopo River basin, particularly in this era of global warming and a changing climate. Keywords: nonstationary extremes; annual maxima; lower Limpopo River; generalised extreme value

Adaptive pitch control for load mitigation of wind turbines

Science.gov (United States)

Yuan, Yuan; Tang, J.

2015-04-01

In this research, model reference adaptive control is examined for the pitch control of wind turbines that may suffer from reduced life owing to extreme loads and fatigue when operated under a high wind speed. Specifically, we aim at making a trade-off between the maximum energy captured and the load induced. The adaptive controller is designed to track the optimal generator speed and at the same time to mitigate component loads under turbulent wind field and other uncertainties. The proposed algorithm is tested on the NREL offshore 5-MW baseline wind turbine, and its performance is compared with that those of the gain scheduled proportional integral (GSPI) control and the disturbance accommodating control (DAC). The results show that the blade root flapwise load can be reduced at a slight expense of optimal power output. The generator speed regulation under adaptive controller is better than DAC.

Rigid MATLAB drivetrain model of a 500 kW wind turbine for predicting maximum gear tooth stresses in a planetary gearbox using multibody gear constraints

DEFF Research Database (Denmark)

Jørgensen, Martin Felix; Pedersen, Niels Leergaard; Sørensen, Jens Nørkær

2014-01-01

multiple planetary gears are not taken into account. Finite Element Method (FEM) calculations show that when the wind turbine runs close to the maximum wind speed, the maximum gear tooth stress is in the range of 500–700 MPa, which is considered to be realistic using a “worst-case” method. The presented...... for not only transferring torque but also for calculating the gear tooth and internal body reaction forces. The method is appropriate for predicting gear tooth stresses without considering all the complexity of gear tooth geometries. This means that, e.g. gear tooth load-sharing and load-distribution among...

DAILY STEM GROWTH PATTERN IN IRRIGATED APPLE ORCHARDS FROM ARGES COUNTY IN RELATION TO CLIMATE CHANGES

Directory of Open Access Journals (Sweden)

E. Chitu

2012-01-01

Full Text Available In terms of climate change manifested in the last 30 years in Romania (1982-2011, average data for 29 localities and characterized by a significant increase in maximum and minimum temperatures, especially in the summer months and increased rainfall deficit, fruit trees farm efficiency is becoming increasingly dependent on strict control of water management through irrigation systems. Thus, the maximum air temperatures experienced average growth trend per decade of 0.88°C, 0.82°C and 0.70°C in June, July and August, respectively, and minimum of 0.61°C, 0.67°C and 0.75°C, in the same months. In this context, ensuring continuous easily accessible soil water content to the root system of the trees, in correlation with plant consumption, has become the most widely used measure to mitigate the negative effects of rising temperatures and rainfall deficits. One of the most accurate methods of water stress early diagnosis and monitoring in a very short step of the fruit trees growth processes is the measurement of trunk diameter variations (SDV with electronic dendrometers. To highlight the advantages of applying the method to irrigated apple (Malus domestica Borkh. plantations from the southern Romania, we have organized two experiences with Redix and Braeburn cvs. grafted on M9 in 2009-2012 period. For measurements were used DEX 100 (Dynamax dendrometers and GP1 dataloggers (Delta-T Devices. It was found that all SDV-derived indices (maximum daily shrinkage (MDS, daily recovery (DR and daily growth (DG of the trees trunk between two successive days may be used for early diagnosis of water and temperature stress. DG was significantly negatively influenced by MDS in both cultivars and in all months of the year, except in September. The Redix cv. DG was inhibited only by the MDS values greater than 0.36 mm. DG is a much less sensitive indicator of water and heat trees stress than MDS. Emergence of water stress was highlighted by two indicators: soil

Analyzing the effects of mechanical and osmotic loading on glycosaminoglycan synthesis rate in cartilaginous tissues.

Science.gov (United States)

Gao, Xin; Zhu, Qiaoqiao; Gu, Weiyong

2015-02-26

The glycosaminoglycan (GAG) plays an important role in cartilaginous tissues to support and transmit mechanical loads. Many extracellular biophysical stimuli could affect GAG synthesis by cells. It has been hypothesized that the change of cell volume is a primary mechanism for cells to perceive the stimuli. Experimental studies have shown that the maximum synthesis rate of GAG is achieved at an optimal cell volume, larger or smaller than this level the GAG synthesis rate decreases. Based on the hypothesis and experimental findings in the literature, we proposed a mathematical model to quantitatively describe the cell volume dependent GAG synthesis rate in the cartilaginous tissues. Using this model, we investigated the effects of osmotic loading and mechanical loading on GAG synthesis rate. It is found our proposed mathematical model is able to well describe the change of GAG synthesis rate in isolated cells or in cartilage with variations of the osmotic loading or mechanical loading. This model is important for evaluating the GAG synthesis activity within cartilaginous tissues as well as understanding the role of mechanical loading in tissue growth or degeneration. It is also important for designing a bioreactor system with proper extracellular environment or mechanical loading for growing tissue at the maximum synthesis rate of the extracellular matrix. Copyright © 2015 Elsevier Ltd. All rights reserved.

Benzo[a]pyrene in urban environments of eastern Moscow: pollution levels and critical loads

Science.gov (United States)

Kasimov, Nikolay S.; Kosheleva, Natalia E.; Nikiforova, Elena M.; Vlasov, Dmitry V.

2017-02-01

Polycyclic aromatic hydrocarbons (PAHs), particularly benzo[a]pyrene (BaP), are toxic compounds emitted from various anthropogenic sources. Understanding the BaP concentrations, dynamics and decomposition in soil is required to assess the critical loads of BaP in urban environments. This study is the first attempt to evaluate all major input and output components of benzo[a]pyrene (BaP) balance and to calculate the permissible load on the urban environment in different land-use zones in the Eastern district of Moscow. BaP contamination of the snow cover in the Eastern district of Moscow was related to daily BaP fallout from the atmosphere. In 2010, the mean content of the pollutant in the snow dust was 1942 ng g-1, whereas the average intensity of its fallout was 7.13 ng m-2 per day. Across the territory, BaP winter fallout intensities varied from 0.3 to 1100 ng m-2 per day. The average BaP content in the surface (0-10 cm) soil horizons was 409 ng g-1, which is 83 times higher than the local background value and 20 times higher than the maximum permissible concentration (MPC) accepted in Russia. The variations in soil and snow BaP concentrations among different land-use zones were examined. A significant contribution of BaP from the atmosphere to urban soils was identified. Based on the measurements of BaP atmospheric fallout and BaP reserves in the soils, the critical loads of BaP for the land-use zones in the Eastern district were calculated for different values of degradation intensity and different exposure times. It was established that at an annual degradation intensity of 1-10 %, ecologically safe BaP levels in the soils of all land-use zones, excluding the agricultural zone, will only be reached after many decades or centuries.

Transcription through the eye of a needle: daily and annual cyclic gene expression variation in Douglas-fir needles.

Science.gov (United States)

Cronn, Richard; Dolan, Peter C; Jogdeo, Sanjuro; Wegrzyn, Jill L; Neale, David B; St Clair, J Bradley; Denver, Dee R

2017-07-24

Perennial growth in plants is the product of interdependent cycles of daily and annual stimuli that induce cycles of growth and dormancy. In conifers, needles are the key perennial organ that integrates daily and seasonal signals from light, temperature, and water availability. To understand the relationship between seasonal cycles and seasonal gene expression responses in conifers, we examined diurnal and circannual needle mRNA accumulation in Douglas-fir (Pseudotsuga menziesii) needles at diurnal and circannual scales. Using mRNA sequencing, we sampled 6.1 × 10 9 reads from 19 trees and constructed a de novo pan-transcriptome reference that includes 173,882 tree-derived transcripts. Using this reference, we mapped RNA-Seq reads from 179 samples that capture daily and annual variation. We identified 12,042 diurnally-cyclic transcripts, 9299 of which showed homology to annotated genes from other plant genomes, including angiosperm core clock genes. Annual analysis revealed 21,225 circannual transcripts, 17,335 of which showed homology to annotated genes from other plant genomes. The timing of maximum gene expression is associated with light intensity at diurnal scales and photoperiod at annual scales, with approximately half of transcripts reaching maximum expression +/- 2 h from sunrise and sunset, and +/- 20 days from winter and summer solstices. Comparisons with published studies from other conifers shows congruent behavior in clock genes with Japanese cedar (Cryptomeria), and a significant preservation of gene expression patterns for 2278 putative orthologs from Douglas-fir during the summer growing season, and 760 putative orthologs from spruce (Picea) during the transition from fall to winter. Our study highlight the extensive diurnal and circannual transcriptome variability demonstrated in conifer needles. At these temporal scales, 29% of expressed transcripts show a significant diurnal cycle, and 58.7% show a significant circannual cycle. Remarkably

Experimental Investigation on Fatigue Behavior of Epoxy Resin under Load and Displacement Controls

Directory of Open Access Journals (Sweden)

Mahmood Mehrdad Shokrieh

2014-12-01

Full Text Available The mechanical properties of epoxy resin including tensile and flexural modulus, tensile and flexural strength for static conditions are currently studied. The frequency effect as significant parameter at room temperature is investigated and fatigue behavior of the epoxy resin in tension-tension loading conditions for different frequencies of 2, 3 and 5 Hz are obtained. The epoxy resin has been taken under flexural bending fatigue loading and fatigue life is investigated. The results of the experiments show the values of 2.5 and 3 GPa of tensile and flexural modules and 59.98 and 110.02 MPa of tensile and flexural strengths for the resin, respectively. To achieve a linear load-deflection relationship in a three-point bending experiment, a maximum allowable deflection of 5 mm is acquired. The relationship between the frequency and fatigue life shows higher frequency results in lower fatigue life. Loading with frequency of 2 Hz has provided 5.8 times more fatigue life compared with 5 Hz loading. For a tension-tension fatigue loading condition, the variation of tensile module of epoxy resin shows no noticeable change during the fatigue loading condition. This module decreases significantly only in the primary and failure cycles close to the fracture point. In further experiments, fatigue behavior of epoxy resin was tested under flexural bending fatigue loadings with controlled deflection at room temperature. Maximum applied normalized stresses versus the number of cycles to failure curve are illustrated and it can be performed in order to predict the number of cycles to failure for the resin in arbitrary applied normal stresses as well.

Analysis of Load-Carrying Capacity for Redundant Free-Floating Space Manipulators in Trajectory Tracking Task

Directory of Open Access Journals (Sweden)

Qingxuan Jia

2014-01-01

Full Text Available The aim of this paper is to analyze load-carrying capacity of redundant free-floating space manipulators (FFSM in trajectory tracking task. Combined with the analysis of influential factors in load-carrying process, evaluation of maximum load-carrying capacity (MLCC is described as multiconstrained nonlinear programming problem. An efficient algorithm based on repeated line search within discontinuous feasible region is presented to determine MLCC for a given trajectory of the end-effector and corresponding joint path. Then, considering the influence of MLCC caused by different initial configurations for the starting point of given trajectory, a kind of maximum payload initial configuration planning method is proposed by using PSO algorithm. Simulations are performed for a particular trajectory tracking task of the 7-DOF space manipulator, of which MLCC is evaluated quantitatively. By in-depth research of the simulation results, significant gap between the values of MLCC when using different initial configurations is analyzed, and the discontinuity of allowable load-carrying capacity is illustrated. The proposed analytical method can be taken as theoretical foundation of feasibility analysis, trajectory optimization, and optimal control of trajectory tracking task in on-orbit load-carrying operations.

Does combined strength training and local vibration improve isometric maximum force? A pilot study.

Science.gov (United States)

Goebel, Ruben; Haddad, Monoem; Kleinöder, Heinz; Yue, Zengyuan; Heinen, Thomas; Mester, Joachim

2017-01-01

The aim of the study was to determine whether a combination of strength training (ST) and local vibration (LV) improved the isometric maximum force of arm flexor muscles. ST was applied to the left arm of the subjects; LV was applied to the right arm of the same subjects. The main aim was to examine the effect of LV during a dumbbell biceps curl (Scott Curl) on isometric maximum force of the opposite muscle among the same subjects. It is hypothesized, that the intervention with LV produces a greater gain in isometric force of the arm flexors than ST. Twenty-seven collegiate students participated in the study. The training load was 70% of the individual 1 RM. Four sets with 12 repetitions were performed three times per week during four weeks. The right arm of all subjects represented the vibration trained body side (VS) and the left arm served as the traditional trained body side (TTS). A significant increase of isometric maximum force in both body sides (Arms) occurred. VS, however, significantly increased isometric maximum force about 43% in contrast to 22% of the TTS. The combined intervention of ST and LC improves isometric maximum force of arm flexor muscles. III.

Clean Water Act Section 303(d) Water Quality Limited Segments, California, 2006, State Water Resources Control Board

Data.gov (United States)

U.S. Environmental Protection Agency — 2006 303d List of Water Quality Limited Segments that: 1) Require Total Maximum Daily Loads (TMDLS), 2) Are being addressed by USEPA approved TMDLs 3) Are being...

Strength and behavior in shear of reinforced concrete deep beams under dynamic loading conditions

Energy Technology Data Exchange (ETDEWEB)

Adhikary, Satadru Das [School of Civil and Environmental Engineering, Nanyang Technological University, 639798 (Singapore); Li, Bing, E-mail: cbli@ntu.edu.sg [School of Civil and Environmental Engineering, Nanyang Technological University, 639798 (Singapore); Fujikake, Kazunori [Department of Civil and Environmental Engineering, National Defense Academy, Yokosuka 239 8686 (Japan)

2013-06-15

Highlights: ► Effects of wider range of loading rates on dynamic shear behavior of RC deep beams. ► Experimental investigation of RC deep beam with and without shear reinforcements. ► Verification of experimental results with truss model and FE simulation results. ► Empirical equations are proposed to predict the dynamic increase factor of maximum resistance. -- Abstract: Research on reinforced concrete (RC) deep beams has seen considerable headway over the past three decades; however, information on the dynamic shear strength and behavior of RC deep beams under varying rates of loads remains limited. This paper describes the experimental results of 24 RC deep beams with and without shear reinforcements under varying rates of concentrated loading. Results obtained serve as useful data on shear resistance, failure patterns and strain rates corresponding to varying loading rates. An analytical truss model approach proves its efficacy in predicting the dynamic shear resistance under varying loading rates. Furthermore, three-dimensional nonlinear finite element (FE) model is described and the simulation results are verified with the experimental results. A parametric study is then conducted to investigate the influence of longitudinal reinforcement ratio, transverse reinforcement ratio and shear span to effective depth ratio on shear behavior. Subsequently, two empirical equations were proposed by integrating the various parameters to assess the dynamic increase factor (DIF) of maximum resistance under varying rates of concentrated loading.

Investigation of Squeeze Film Damping and Associated Loads

DEFF Research Database (Denmark)

Johansen, Per; Bender, Niels Christian; Hansen, Anders Hedegaard

2017-01-01

-viscous case. In consequence, this enable insights concerning the influence of piezo-viscosity on this damping effect. These models are used to investigate the loads, which the approaching surfaces experiences. Based on Hertzian theory, comparisons of impact loads and the dynamic squeeze loading are performed......Digital hydraulics have attracted attention towards fast switching valves and the increased focus on reliable fluid power entail that the lifetime of such valves is of great concern. An inherent feature of most valves for digital hydraulics is that of a mechanical end stop. Consequently...... is reviewed with a focus on maximum surface stresses. Using the Barus relation for viscosity-pressure dependency and different film geometries, the classical lubrication theory is applied together with the equation of motion, to obtain the gap height motion equation, both for the iso-viscous and piezo...

Daily temperature records from a mesonet in the foothills of the Canadian Rocky Mountains, 2005-2010

Science.gov (United States)

Wood, Wendy H.; Marshall, Shawn J.; Whitehead, Terri L.; Fargey, Shannon E.

2018-03-01

Near-surface air temperatures were monitored from 2005 to 2010 in a mesoscale network of 230 sites in the foothills of the Rocky Mountains in southwestern Alberta, Canada. The monitoring network covers a range of elevations from 890 to 2880 m above sea level and an area of about 18 000 km2, sampling a variety of topographic settings and surface environments with an average spatial density of one station per 78 km2. This paper presents the multiyear temperature dataset from this study, with minimum, maximum, and mean daily temperature data available at https://doi.org/10.1594/PANGAEA.880611" target="_blank">https://doi.org/10.1594/PANGAEA.880611. In this paper, we describe the quality control and processing methods used to clean and filter the data and assess its accuracy. Overall data coverage for the study period is 91 %. We introduce a weather-system-dependent gap-filling technique to estimate the missing 9 % of data. Monthly and seasonal distributions of minimum, maximum, and mean daily temperature lapse rates are shown for the region.

A comparison of climatological observing windows and their impact on detecting daily temperature extrema

Science.gov (United States)

Žaknić-Ćatović, Ana; Gough, William A.

2018-04-01

Climatological observing window (COW) is defined as a time frame over which continuous or extreme air temperature measurements are collected. A 24-h time interval, ending at 00UTC or shifted to end at 06UTC, has been associated with difficulties in characterizing daily temperature extrema. A fixed 24-h COW used to obtain the temperature minima leads to potential misidentification due to fragmentation of "nighttime" into two subsequent nighttime periods due to the time discretization interval. The correct identification of air temperature extrema is achievable using a COW that identifies daily minimum over a single nighttime period and maximum over a single daytime period, as determined by sunrise and sunset. Due to a common absence of hourly air temperature observations, the accuracy of the mean temperature estimation is dependent on the accuracy of determination of diurnal air temperature extrema. Qualitative and quantitative criteria were used to examine the impact of the COW on detecting daily air temperature extrema. The timing of the 24-h observing window occasionally affects the determination of daily extrema through a mischaracterization of the diurnal minima and by extension can lead to errors in determining daily mean temperature. Hourly air temperature data for the time period from year 1987 to 2014, obtained from Toronto Buttonville Municipal Airport weather station, were used in analysis of COW impacts on detection of daily temperature extrema and calculation of annual temperature averages based on such extrema.

DESIGN OF STRUCTURAL ELEMENTS IN THE EVENT OF THE PRE-SET RELIABILITY, REGULAR LOAD AND BEARING CAPACITY DISTRIBUTION

Directory of Open Access Journals (Sweden)

Tamrazyan Ashot Georgievich

2012-10-01

Full Text Available Accurate and adequate description of external influences and of the bearing capacity of the structural material requires the employment of the probability theory methods. In this regard, the characteristic that describes the probability of failure-free operation is required. The characteristic of reliability means that the maximum stress caused by the action of the load will not exceed the bearing capacity. In this paper, the author presents a solution to the problem of calculation of structures, namely, the identification of reliability of pre-set design parameters, in particular, cross-sectional dimensions. If the load distribution pattern is available, employment of the regularities of distributed functions make it possible to find the pattern of distribution of maximum stresses over the structure. Similarly, we can proceed to the design of structures of pre-set rigidity, reliability and stability in the case of regular load distribution. We consider the element of design (a monolithic concrete slab, maximum stress S which depends linearly on load q. Within a pre-set period of time, the probability will not exceed the values according to the Poisson law. The analysis demonstrates that the variability of the bearing capacity produces a stronger effect on relative sizes of cross sections of a slab than the variability of loads. It is therefore particularly important to reduce the coefficient of variation of the load capacity. One of the methods contemplates the truncation of the bearing capacity distribution by pre-culling the construction material.

Typical load shapes for six categories of Swedish commercial buildings

Energy Technology Data Exchange (ETDEWEB)

Noren, C.

1997-01-01

In co-operation with several Swedish electricity suppliers, typical load shapes have been developed for six categories of commercial buildings located in the south of Sweden. The categories included in the study are: hotels, warehouses/grocery stores, schools with no kitchen, schools with kitchen, office buildings, health, health buildings. Load shapes are developed for different mean daily outdoor temperatures and for different day types, normally standard weekdays and standard weekends. The load shapes are presented as non-dimensional normalized 1-hour load. All measured loads for an object are divided by the object`s mean load during the measuring period and typical load shapes are developed for each category of buildings. Thus errors were kept lower as compared to use of W/m{sup 2}-terms. Typical daytime (9 a.m. - 5 p.m.) standard deviations are 7-10% of the mean values for standard weekdays but during very cold or warm weather conditions, single objects can deviate from the typical load shape. On weekends, errors are higher and depending on very different activity levels in the buildings, it is difficult to develop weekend load shapes with good accuracy. The method presented is very easy to use for similar studies and no building simulation programs are needed. If more load data is available, a good method to lower the errors is to make sure that every category only consists of objects with the same activity level, both on weekdays and weekends. To make it easier to use the load shapes, Excel load shape workbooks have been developed, where it is even possible to compare typical load shapes with measured data. 23 refs, 53 figs, 20 tabs

Solar cycle 22 control on daily geomagnetic variation at Terra Nova Bay (Antarctica

Directory of Open Access Journals (Sweden)

P. Palangio

1998-06-01

Full Text Available Nine summer geomagnetic observatory data (1986-1995 from Terra Nova Bay Base, Antarctica (Lat.74.690S, Long. 164.120E, 80.040S magnetic latitude are used to investigate the behaviour of the daily variation of the geomagnetic field at polar latitude. The instrumentation includes a proton precession magnetometer for total intensity |F| digital recordings; DI magnetometers for absolute measuring of the angular elements D and I and a three axis flux-gate system for acquiring H,D Z time variation data. We find that the magnetic time variation amplitude follows the solar cycle evolution and that the ratio between minimum solar median and maximum solar median is between 2-3 for intensive elements (H and Z and 1.7 for declination(D. The solar cycle effect on geomagnetic daily variation elements amplitude in Antarctica, in comparison with previous studies, is then probably larger than expected. As a consequence, the electric current system that causes the daily magnetic field variation reveals a quite large solar cycle effect at Terra Nova Bay.

Batch medication of intestinal infections in nursery pigs—A randomised clinical trial on the efficacy of treatment strategy, type of antibiotic and bacterial load on average daily weight gain

DEFF Research Database (Denmark)

Weber, Nicolai Rosager; Pedersen, Ken Steen; Hansen, Christian Fink

2017-01-01

after weaning) on average daily weight gain (ADG); (2) to compare the effect of treatment with doxycycline or tylosine on diarrhoea prevalence, pathogenic bacterial load, and ADG; (3) to evaluate PCR testing of faecal pen floor samples as a diagnostic tool for determining the optimal time of treatment...... difference (p = 0.04) of mean diarrhoea prevalence on day 21 of the study between pens treated with tylosine (0.254, 95% CI: 0.184–0.324), and doxycycline (0.167, 95% CI: 0.124–0.210). The type of antibiotic compound was not found to have a significant effect on ADG (p = 0.209). (3) Pigs starting treatment...... was achieved when treatment was initiated 14 days after weaning in pens where intestinal pathogens were detected. Doxycycline was more effective in reducing diarrhoea and LI excretion levels than treatment with tylosine....

Coherent Lidar Turbulence Measurement for Gust Load Alleviation

Science.gov (United States)

Bogue, Rodney K.; Ehernberger, L. J.; Soreide, David; Bagley, Hal

1996-01-01

Atmospheric turbulence adversely affects operation of commercial and military aircraft and is a design constraint. The airplane structure must be designed to survive the loads imposed by turbulence. Reducing these loads allows the airplane structure to be lighter, a substantial advantage for a commercial airplane. Gust alleviation systems based on accelerometers mounted in the airplane can reduce the maximum gust loads by a small fraction. These systems still represent an economic advantage. The ability to reduce the gust load increases tremendously if the turbulent gust can be measured before the airplane encounters it. A lidar system can make measurements of turbulent gusts ahead of the airplane, and the NASA Airborne Coherent Lidar for Advanced In-Flight Measurements (ACLAIM) program is developing such a lidar. The ACLAIM program is intended to develop a prototype lidar system for use in feasibility testing of gust load alleviation systems and other airborne lidar applications, to define applications of lidar with the potential for improving airplane performance, and to determine the feasibility and benefits of these applications. This paper gives an overview of the ACLAIM program, describes the lidar architecture for a gust alleviation system, and describes the prototype ACLAIM lidar system.

Robust Controller to Extract the Maximum Power of a Photovoltaic System

Directory of Open Access Journals (Sweden)

OULD CHERCHALI Noureddine

2014-05-01

Full Text Available This paper proposes a technique of intelligent control to track the maximum power point (MPPT of a photovoltaic system . The PV system is non-linear and it is exposed to external perturbations like temperature and solar irradiation. Fuzzy logic control is known for its stability and robustness. FLC is adopted in this work for the improvement and optimization of control performance of a photovoltaic system. Another technique called perturb and observe (P & O is studied and compared with the FLC technique. The PV system is constituted of a photovoltaic panel (PV, a DC-DC converter (Boost and a battery like a load. The simulation results are developed in MATLAB / Simulink software. The results show that the controller based on fuzzy logic is better and faster than the conventional controller perturb and observe (P & O and gives a good maximum power of a photovoltaic generator under different changes of weather conditions.

Maximum-likelihood methods for array processing based on time-frequency distributions

Science.gov (United States)

Zhang, Yimin; Mu, Weifeng; Amin, Moeness G.

1999-11-01

This paper proposes a novel time-frequency maximum likelihood (t-f ML) method for direction-of-arrival (DOA) estimation for non- stationary signals, and compares this method with conventional maximum likelihood DOA estimation techniques. Time-frequency distributions localize the signal power in the time-frequency domain, and as such enhance the effective SNR, leading to improved DOA estimation. The localization of signals with different t-f signatures permits the division of the time-frequency domain into smaller regions, each contains fewer signals than those incident on the array. The reduction of the number of signals within different time-frequency regions not only reduces the required number of sensors, but also decreases the computational load in multi- dimensional optimizations. Compared to the recently proposed time- frequency MUSIC (t-f MUSIC), the proposed t-f ML method can be applied in coherent environments, without the need to perform any type of preprocessing that is subject to both array geometry and array aperture.

Short-Term City Electric Load Forecasting with Considering Temperature Effects: An Improved ARIMAX Model

Directory of Open Access Journals (Sweden)

Herui Cui

2015-01-01

Full Text Available Short-term electric load is significantly affected by weather, especially the temperature effects in summer. External factors can result in mutation structures in load data. Under the influence of the external temperature factors, city electric load cannot be easily forecasted as usual. This research analyzes the relationship between electricity load and daily temperature in city. An improved ARIMAX model is proposed in this paper to deal with the mutation data structures. It is found that information amount of the improved ARIMAX model is smaller than that of the classic method and its relative error is less than AR, ARMA and Sigmoid-Function ANN models. The forecasting results are more accurately fitted. This improved model is highly valuable when dealing with mutation data structure in the field of load forecasting. And it is also an effective technique in forecasting electric load with temperature effects.

Daily Weather Records

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These daily weather records were compiled from a subset of stations in the Global Historical Climatological Network (GHCN)-Daily dataset. A weather record is...

75 FR 20351 - Clean Water Act Section 303(d): Availability of One Total Maximum Daily Load (TMDL) in Arkansas

Science.gov (United States)

2010-04-19

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9139-5] Clean Water Act Section 303(d): Availability of One...: Notice of availability. SUMMARY: This notice announces the availability of the administrative record file... in the State of Arkansas under Section 303(d) of the Clean Water Act (CWA). This TMDL was completed...

75 FR 8698 - Clean Water Act Section 303(d): Availability of Ten Total Maximum Daily Loads (TMDLs) in Louisiana

Science.gov (United States)

2010-02-25

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9118-5] Clean Water Act Section 303(d): Availability of Ten...: Notice of availability. SUMMARY: This notice announces the availability for comment on the administrative... Smith, Environmental Protection Specialist, Water Quality Protection Division, U.S. Environmental...

76 FR 76161 - Clean Water Act Section 303(d): Availability of Three Total Maximum Daily Loads (TMDLs) in Louisiana

Science.gov (United States)

2011-12-06

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9500-1] Clean Water Act Section 303(d): Availability of Three...: Notice of availability. SUMMARY: This notice announces the availability for comment on the administrative... Smith, Environmental Protection Specialist, Water Quality Protection Division, U.S. Environmental...

76 FR 70442 - Clean Water Act Section 303(d): Availability of 28 Total Maximum Daily Loads (TMDLs) in Louisiana

Science.gov (United States)

2011-11-14

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9491-1] Clean Water Act Section 303(d): Availability of 28...: Notice of availability. SUMMARY: This notice announces the availability for comment on the administrative..., Environmental Protection Specialist, Water Quality Protection Division, U.S. Environmental Protection Agency...

76 FR 77226 - Clean Water Act Section 303(d): Availability of 28 Total Maximum Daily Loads (TMDLs) in Louisiana

Science.gov (United States)

2011-12-12

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9505-4] Clean Water Act Section 303(d): Availability of 28... public comment period for the notice of availability that published on November 14, 2011, 76 FR 70442... Protection Specialist, Water Quality Protection Division, U.S. Environmental Protection Agency Region 6, 1445...

76 FR 80366 - Clean Water Act Section 303(d): Availability of One Total Maximum Daily Load (TMDL) in Louisiana

Science.gov (United States)

2011-12-23

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9610-6] Clean Water Act Section 303(d): Availability of One...: Notice of availability. SUMMARY: This notice announces the availability for comment on the administrative..., Environmental Protection Specialist, Water Quality Protection Division, U.S. Environmental Protection Agency...

Aspects of alienation and symptom load among adolescents.

Science.gov (United States)

Rayce, Signe L B; Holstein, Bjørn E; Kreiner, Svend

2009-01-01

The purpose was to examine the association between aspects of alienation and symptom load among adolescents. Furthermore an integrated purpose was to construct and validate an index of alienation. Cross-sectional data from 5205 school children aged 11-15 years from a random sample of schools in Denmark were used. Data stems from the Danish contribution to the cross-national study Health and Behaviour in School-aged Children (HBSC). Alienation was measured with a new index fulfilling four criteria: (i) theoretical foundation, (ii) inter-correlation between items, (iii) correlation between each of the index's items and the outcomes and (iv) no differential item functioning. The final index included three indicators of alienation: helplessness, feeling left out of things and lack of confidentiality with parents. Symptom load was measured by HBSC Symptom Checklist and divided into physical and psychological symptoms respectively. High symptom load was defined as experiencing at least one symptom on a daily basis. The odds-ratio (OR) for high symptom load increased with the degree of alienation. For students with all three indicators of alienation, the OR for high physical symptom load was 2.49 (1.05-5.87). The OR for high psychological symptom load for the corresponding degree of alienation was 6.50 (3.11-13.56). The index of alienation fulfilled psychometric criteria for scalability. Furthermore the analyses showed a graded and significant association between alienation and high symptom load. This suggests alienation to be taken into account in future health interventions among adolescents. In school settings this may be done using principles of empowerment.

Analysis of Dissolved Selenium Loading for Selected Sites in the Lower Gunnison River Basin, Colorado, 1978-2005

Science.gov (United States)

Thomas, Judith C.; Leib, Kenneth J.; Mayo, John W.

2008-01-01

Elevated selenium concentrations in streams are a water-quality concern in western Colorado. The U.S. Geologic Survey, in cooperation with the Colorado Department of Public Health and Environment, summarized selenium loading in the Lower Gunnison River Basin to support the development of total maximum daily selenium loads at sites that represent the cumulative contribution to U.S. Environmental Protection Agency 303(d) list segments. Analysis of selenium loading included quantifying loads and determining the amount of load that would need to be reduced to bring the site into compliance, referred to as 'the load reduction,' with the State chronic aquatic-life standard for dissolved selenium [85th percentile selenium concentration not to exceed 4.6 ?g/L (micrograms per liter)], referred to as 'the water-quality standard.' Streamflow and selenium concentration data for 54 historical water-quality/water-quantity monitoring sites were compiled from U.S. Geological Survey and Colorado Department of Public Health and Environment data sources. Three methods were used for analysis of selenium concentration data to address the variable data density among sites. Mean annual selenium loads were determined for only 10 of the 54 sites due to data availability limitations. Twenty-two sites had 85th percentile selenium concentrations that exceeded the water-quality standard, 3 sites had 85th percentile selenium concentrations less than the State standard, and 29 sites could not be evaluated with respect to 85th percentile selenium concentration (sample count less than 5). To bring selenium concentrations into compliance with the water-quality standard, more than 80 percent of the mean annual selenium load would need to be reduced at Red Rock Canyon, Dry Cedar Creek, Cedar Creek, Loutzenhizer Arroyo, Sunflower Drain, and Whitewater Creek. More than 50 percent of the mean annual load would need to be reduced at Dry Creek to bring the site into compliance with the water

Understanding Adherence to Daily and Intermittent Regimens of Oral HIV Pre-exposure Prophylaxis Among Men Who Have Sex with Men in Kenya

OpenAIRE

Mugo, Peter Mwangi; Sanders, Eduard J.; Mutua, Gaudensia; van der Elst, Elisabeth; Anzala, Omu; Barin, Burc; Bangsberg, David R.; Priddy, Frances H.; Haberer, Jessica E.

2014-01-01

A qualitative assessment of Kenyan men who have sex with men taking daily and intermittent oral HIV pre-exposure prophylaxis (PrEP) found stigma, sex work, mobility, and alcohol impacted adherence. We analyzed quantitative data from the same cohort to explore different definitions of intermittent adherence. Volunteers were randomized to daily emtricitabine/tenofovir or placebo, or intermittent (prescription: Mondays/Fridays/after sex, maximum 1 dose/day) emtricitabine/tenofovir or placebo (2:...

Optimization of Boiler Control to Improve the Load-following Capability of Power-plant Units

DEFF Research Database (Denmark)

Mortensen, J. H.; Mølbak, T.; Andersen, Palle

The capability to perform fast load changes has been an important issue in the power market, and will become increasingly more so due to the incresing commercialisation of the European power market. An optimizing control system for improving the load-following capability of power-plant units has...... tests on a 265 MW coal-fired power-plant unit reveals that the maximum allowable load gradient that can be imposed on the plant, can be increased from 4 MW/min. to 8 MW/min....

Optimization of Boiler Control to Improve the Load-following Capability of Power-plant Units

DEFF Research Database (Denmark)

Mortensen, J. H.; Mølbak, T.; Andersen, Palle

1998-01-01

The capability to perform fast load changes has been an important issue in the power market, and will become increasingly more so due to the incresing commercialisation of the European power market. An optimizing control system for improving the load-following capability of power-plant units has...... tests on a 265 MW coal-fired power-plant unit reveals that the maximum allowable load gradient that can be imposed on the plant, can be increased from 4 MW/min. to 8 MW/min....

Loading functions for assessment of water pollution from nonpoint sources. Final report

International Nuclear Information System (INIS)

McElroy, A.D.; Chiu, S.Y.; Nebgen, J.W.; Aleti, A.; Bennett, F.W.

1976-05-01

Methods for evaluating the quantity of water pollutants generated from nonpoint sources including agriculture, silviculture, construction, mining, runoff from urban areas and rural roads, and terrestrial disposal are developed and compiled for use in water quality planning. The loading functions, plus in some instances emission values, permit calculation of nonpoint source pollutants from available data and information. Natural background was considered to be a source and loading functions were presented to estimate natural or background loads of pollutants. Loading functions/values are presented for average conditions, i.e., annual average loads expressed as metric tons/hectare/year (tons/acre/year). Procedures for estimating seasonal or 30-day maximum and minimum loads are also presented. In addition, a wide variety of required data inputs to loading functions, and delineation of sources of additional information are included in the report. The report also presents an evaluation of limitations and constraints of various methodologies which will enable the user to employ the functions realistically

Managing Daily Life

Science.gov (United States)

... Duchenne / Managing Daily Life Print Email Managing Daily Life Environmental accessibility As the person with Duchenne starts ... such as wider doorways and ramps, can make life easier once the person with Duchenne cannot climb ...

Activities of everyday life with high spinal loads.

Directory of Open Access Journals (Sweden)

Antonius Rohlmann

Full Text Available Activities with high spinal loads should be avoided by patients with back problems. Awareness about these activities and knowledge of the associated loads are important for the proper design and pre-clinical testing of spinal implants. The loads on an instrumented vertebral body replacement have been telemetrically measured for approximately 1000 combinations of activities and parameters in 5 patients over a period up to 65 months postoperatively. A database containing, among others, extreme values for load components in more than 13,500 datasets was searched for 10 activities that cause the highest resultant force, bending moment, torsional moment, or shear force in an anatomical direction. The following activities caused high resultant forces: lifting a weight from the ground, forward elevation of straight arms with a weight in hands, moving a weight laterally in front of the body with hanging arms, changing the body position, staircase walking, tying shoes, and upper body flexion. All activities have in common that the center of mass of the upper body was moved anteriorly. Forces up to 1650 N were measured for these activities of daily life. However, there was a large intra- and inter-individual variation in the implant loads for the various activities depending on how exercises were performed. Measured shear forces were usually higher in the posterior direction than in the anterior direction. Activities with high resultant forces usually caused high values of other load components.

Enhancing nitrogen removal in stormwater treatment facilities for transportation.

Science.gov (United States)

2015-01-01

Stormwater from roadways is a point source of pollution. State DOTs must comply with Total Maximum : Daily Load (TMDL) regulations for nutrients such as nitrogen, which causes water quality impairment. Existing stormwater treatment technologies, such...

Support Vector Regression Model Based on Empirical Mode Decomposition and Auto Regression for Electric Load Forecasting

Directory of Open Access Journals (Sweden)

Hong-Juan Li

2013-04-01

Full Text Available Electric load forecasting is an important issue for a power utility, associated with the management of daily operations such as energy transfer scheduling, unit commitment, and load dispatch. Inspired by strong non-linear learning capability of support vector regression (SVR, this paper presents a SVR model hybridized with the empirical mode decomposition (EMD method and auto regression (AR for electric load forecasting. The electric load data of the New South Wales (Australia market are employed for comparing the forecasting performances of different forecasting models. The results confirm the validity of the idea that the proposed model can simultaneously provide forecasting with good accuracy and interpretability.

Self-critical perfectionism, daily stress, and disclosure of daily emotional events.

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Richardson, Clarissa M E; Rice, Kenneth G

2015-10-01

Although disclosure of stressful events can alleviate distress, self-critical perfectionism may pose an especially strong impediment to disclosure during stress, likely contributing to poorer psychological well-being. In the current study, after completing a measure of self-critical perfectionism (the Discrepancy subscale of the Almost Perfect Scale--Revised; Slaney, Rice, Mobley, Trippi, & Ashby, 2001), 396 undergraduates completed measures of stress and disclosure at the end of each day for 1 week. Consistent with hypotheses and previous research, multilevel modeling results indicated significant intraindividual coupling of daily stress and daily disclosure where disclosure was more likely when experiencing high stress than low stress. As hypothesized, Discrepancy moderated the relationship between daily stress and daily disclosure. Individuals higher in self-critical perfectionism (Discrepancy) were less likely to engage in disclosure under high stress, when disclosure is often most beneficial, than those with lower Discrepancy scores. These results have implications for understanding the role of stress and coping in the daily lives of self-critical perfectionists. (c) 2015 APA, all rights reserved).

Hybridizing DEMD and Quantum PSO with SVR in Electric Load Forecasting

Directory of Open Access Journals (Sweden)

Li-Ling Peng

2016-03-01

Full Text Available Electric load forecasting is an important issue for a power utility, associated with the management of daily operations such as energy transfer scheduling, unit commitment, and load dispatch. Inspired by strong non-linear learning capability of support vector regression (SVR, this paper presents an SVR model hybridized with the differential empirical mode decomposition (DEMD method and quantum particle swarm optimization algorithm (QPSO for electric load forecasting. The DEMD method is employed to decompose the electric load to several detail parts associated with high frequencies (intrinsic mode function—IMF and an approximate part associated with low frequencies. Hybridized with quantum theory to enhance particle searching performance, the so-called QPSO is used to optimize the parameters of SVR. The electric load data of the New South Wales (Sydney, Australia market and the New York Independent System Operator (NYISO, New York, USA are used for comparing the forecasting performances of different forecasting models. The results illustrate the validity of the idea that the proposed model can simultaneously provide forecasting with good accuracy and interpretability.

Fatigue data for polyether ether ketone (PEEK) under fully-reversed cyclic loading.

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Shrestha, Rakish; Simsiriwong, Jutima; Shamsaei, Nima

2016-03-01

In this article, the data obtained from the uniaxial fully-reversed fatigue experiments conducted on polyether ether ketone (PEEK), a semi-crystalline thermoplastic, are presented. The tests were performed in either strain-controlled or load-controlled mode under various levels of loading. The data are categorized into four subsets according to the type of tests, including (1) strain-controlled fatigue tests with adjusted frequency to obtain the nominal temperature rise of the specimen surface, (2) strain-controlled fatigue tests with various frequencies, (3) load-controlled fatigue tests without step loadings, and (4) load-controlled fatigue tests with step loadings. Accompanied data for each test include the fatigue life, the maximum (peak) and minimum (valley) stress-strain responses for each cycle, and the hysteresis stress-strain responses for each collected cycle in a logarithmic increment. A brief description of the experimental method is also given.

Research on configuration of railway self-equipped tanker based on minimum cost maximum flow model

Science.gov (United States)

Yang, Yuefang; Gan, Chunhui; Shen, Tingting

2017-05-01

In the study of the configuration of the tanker of chemical logistics park, the minimum cost maximum flow model is adopted. Firstly, the transport capacity of the park loading and unloading area and the transportation demand of the dangerous goods are taken as the constraint condition of the model; then the transport arc capacity, the transport arc flow and the transport arc edge weight are determined in the transportation network diagram; finally, the software calculations. The calculation results show that the configuration issue of the tankers can be effectively solved by the minimum cost maximum flow model, which has theoretical and practical application value for tanker management of railway transportation of dangerous goods in the chemical logistics park.

Construction of estimated flow- and load-duration curves for Kentucky using the Water Availability Tool for Environmental Resources (WATER)

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Unthank, Michael D.; Newson, Jeremy K.; Williamson, Tanja N.; Nelson, Hugh L.

2012-01-01

Flow- and load-duration curves were constructed from the model outputs of the U.S. Geological Survey's Water Availability Tool for Environmental Resources (WATER) application for streams in Kentucky. The WATER application was designed to access multiple geospatial datasets to generate more than 60 years of statistically based streamflow data for Kentucky. The WATER application enables a user to graphically select a site on a stream and generate an estimated hydrograph and flow-duration curve for the watershed upstream of that point. The flow-duration curves are constructed by calculating the exceedance probability of the modeled daily streamflows. User-defined water-quality criteria and (or) sampling results can be loaded into the WATER application to construct load-duration curves that are based on the modeled streamflow results. Estimates of flow and streamflow statistics were derived from TOPographically Based Hydrological MODEL (TOPMODEL) simulations in the WATER application. A modified TOPMODEL code, SDP-TOPMODEL (Sinkhole Drainage Process-TOPMODEL) was used to simulate daily mean discharges over the period of record for 5 karst and 5 non-karst watersheds in Kentucky in order to verify the calibrated model. A statistical evaluation of the model's verification simulations show that calibration criteria, established by previous WATER application reports, were met thus insuring the model's ability to provide acceptably accurate estimates of discharge at gaged and ungaged sites throughout Kentucky. Flow-duration curves are constructed in the WATER application by calculating the exceedence probability of the modeled daily flow values. The flow-duration intervals are expressed as a percentage, with zero corresponding to the highest stream discharge in the streamflow record. Load-duration curves are constructed by applying the loading equation (Load = Flow*Water-quality criterion) at each flow interval.

Decrease of dynamic loads in mobile energy means

Science.gov (United States)

Polivaev, O. I.; Gorban, L. K.; Vorohobin, A. V.; Vedrinsky, O. S.

2018-03-01

The increase in the productivity of machine and tractor units is possible due to the increase in operating speeds, this leads to the emergence of increased dynamic loads in the system “engine-transmission-propulsion unit-soil”, which worsens the performance of machine-tractor aggregates. To reduce fluctuations in the “engine-transmission” system, special vibration dampers are used, which installed in close proximity to the engine and protect well the transmission from uneven engine operation; however, such dampers practically do not eliminate the oscillations of external loads. Reducing dynamic loads on the transmission and the mobile power engine (MPE) is an important issue directly related to improving the performance, reliability and durability of the tractor, as well as reducing the slippage of the drive wheels. In order to reduce effectively dynamic loads on the transmission and on the MPE, it is necessary to introduce resilient damping elements closer to the sources of oscillations, namely, to the driving wheels. At the same time, the elastic-damping element should provide accumulation of vibration energy caused by external influences and have a large energy capacity. The installation of an elastic-damping element in the final link of the tractor transmission ensures a reduction in the magnitude of external influences, thereby protecting the engine and transmission from large dynamic loads, and allows one to reduce the slippage of the propellers, which has a positive effect on the traction and energy characteristics of the tractor. Traction tests of the LTP-55 tractor on a concrete road showed that the use of an elasto-damping drive makes it possible to increase the maximum tractive power from 33.5 to 35.3 kW and to reduce the slipping of propellers by 12-30%, the specific fuel consumption by 6-10%. When driving on stubble, the use of an elastic-damping drive increases the maximum tractive power from 25 to 26 kW, reduces the skidding of propellers by

Dependence of Some Mechanical Properties of Elastic Bands on the Length and Load Time

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Triana, C. A.; Fajardo, F.

2012-01-01

We present a study of the maximum stress supported by elastics bands of nitrile as a function of the natural length and the load time. The maximum tension of rupture and the corresponding variation in length were found by measuring the elongation of an elastic band when a mass is suspended from its free end until it reaches the breaking point. The…

Implementation of Maximum Power Point Tracking (MPPT) Solar Charge Controller using Arduino

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Abdelilah, B.; Mouna, A.; KouiderM’Sirdi, N.; El Hossain, A.

2018-05-01

the platform Arduino with a number of sensors standard can be used as components of an electronic system for acquiring measures and controls. This paper presents the design of a low-cost and effective solar charge controller. This system includes several elements such as the solar panel converter DC/DC, battery, circuit MPPT using Microcontroller, sensors, and the MPPT algorithm. The MPPT (Maximum Power Point Tracker) algorithm has been implemented using an Arduino Nano with the preferred program. The voltage and current of the Panel are taken where the program implemented will work and using this algorithm that MPP will be reached. This paper provides details on the solar charge control device at the maximum power point. The results include the change of the duty cycle with the change in load and thus mean the variation of the buck converter output voltage and current controlled by the MPPT algorithm.

A global dataset of sub-daily rainfall indices

Science.gov (United States)

Fowler, H. J.; Lewis, E.; Blenkinsop, S.; Guerreiro, S.; Li, X.; Barbero, R.; Chan, S.; Lenderink, G.; Westra, S.

2017-12-01

It is still uncertain how hydrological extremes will change with global warming as we do not fully understand the processes that cause extreme precipitation under current climate variability. The INTENSE project is using a novel and fully-integrated data-modelling approach to provide a step-change in our understanding of the nature and drivers of global precipitation extremes and change on societally relevant timescales, leading to improved high-resolution climate model representation of extreme rainfall processes. The INTENSE project is in conjunction with the World Climate Research Programme (WCRP)'s Grand Challenge on 'Understanding and Predicting Weather and Climate Extremes' and the Global Water and Energy Exchanges Project (GEWEX) Science questions. A new global sub-daily precipitation dataset has been constructed (data collection is ongoing). Metadata for each station has been calculated, detailing record lengths, missing data, station locations. A set of global hydroclimatic indices have been produced based upon stakeholder recommendations including indices that describe maximum rainfall totals and timing, the intensity, duration and frequency of storms, frequency of storms above specific thresholds and information about the diurnal cycle. This will provide a unique global data resource on sub-daily precipitation whose derived indices will be freely available to the wider scientific community.

Maximum permissible dose

International Nuclear Information System (INIS)

Anon.

1979-01-01

This chapter presents a historic overview of the establishment of radiation guidelines by various national and international agencies. The use of maximum permissible dose and maximum permissible body burden limits to derive working standards is discussed

Relationships Among Nightly Sleep Quality, Daily Stress, and Daily Affect.

Science.gov (United States)

Blaxton, Jessica M; Bergeman, Cindy S; Whitehead, Brenda R; Braun, Marcia E; Payne, Jessic D

2017-05-01

We explored the prospective, microlevel relationship between nightly sleep quality (SQ) and the subsequent day's stress on positive (PA) and negative affect (NA) as well as the moderating relationships between nightly SQ, subsequent stress, and subsequent PA on NA. We investigated whether age moderated these relationships. We collected 56 days of sleep, stress, and affect data using daily diary questionnaires (N = 552). We used multilevel modeling to assess relationships at the between- and within-person levels. Daily increases in SQ and decreases in stress interacted to predict higher daily PA and lower daily NA. Better SQ in older adults enhanced the benefits of PA on the stress-NA relationship more during times of low stress, whereas better sleep in younger adults enhanced the benefits of PA more during times of high stress. Between-person effects were stronger predictors of well-being outcomes than within-person variability. The combination of good SQ and higher PA buffered the impact of stress on NA. The moderating impact of age suggests that sleep and stress play different roles across adulthood. Targeting intervention and prevention strategies to improve SQ and enhance PA could disrupt the detrimental relationship between daily stress and NA. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Loads and loads and loads: the influence of prospective load, retrospective load, and ongoing task load in prospective memory

Science.gov (United States)

Meier, Beat; Zimmermann, Thomas D.

2015-01-01

In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load (OTL) can affect prospective memory performance. The existence of multiple target events increases prospective load (PL) and adding complexity to the to-be-remembered action increases retrospective load (RL). In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of PL on costs in the ongoing task for categorical targets (Experiment 2), but not for specific targets (Experiment 1). RL and OTL both affected remembering the retrospective component of the prospective memory task. We suggest that PL can enhance costs in the ongoing task due to additional monitoring requirements. RL and OTL seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially. PMID:26082709

Loads and loads and loads: the influence of prospective load, retrospective load, and ongoing task load in prospective memory.

Science.gov (United States)

Meier, Beat; Zimmermann, Thomas D

2015-01-01

In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load (OTL) can affect prospective memory performance. The existence of multiple target events increases prospective load (PL) and adding complexity to the to-be-remembered action increases retrospective load (RL). In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of PL on costs in the ongoing task for categorical targets (Experiment 2), but not for specific targets (Experiment 1). RL and OTL both affected remembering the retrospective component of the prospective memory task. We suggest that PL can enhance costs in the ongoing task due to additional monitoring requirements. RL and OTL seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially.

CytoMCS: A Multiple Maximum Common Subgraph Detection Tool for Cytoscape