Search results for "DEMAND"

Match Load Physical Demands in U-19 Professional Soccer Players Assessed by a Wearable Inertial Sensor

2023

Background: Wearable inertial sensors are poorly used in soccer to monitor external load (EL) indicators. However, these devices could be useful for improving sports performance and potentially reducing the risk of injury. The aim of this study was to investigate the EL indicators (i.e., cinematic, mechanical, and metabolic) differences between playing positions (i.e., central backs, external strikers, fullbacks, midfielders, and wide midfielder) during the first half time of four official matches (OMs). Methods: 13 young professional soccer players (Under-19; age: 18.5 ± 0.4 years; height: 177 ± 6 cm; weight: 67 ± 4.8 kg) were monitored through a wearable inertial sens…

Promoting self-employment: Does it create more employment and business activity?

2021

International audience; We assess the economic impact of reforms promoting self-employment in the three countries that have implemented such reforms since the early 2000s: the Netherlands, the United Kingdom and France. To that end, we use an unbalanced cross country-industry dataset of 4,226 observations, including 12 OECD countries and 20 market industries, over the 1995-2016 period. We first observe, using country-level data, that the share of self-employed workers in total employment is quite stable or declines over the period in all countries in our dataset, except in the three countries where large reforms promoting self-employment have been implemented, and only after these reforms. …

Experimental study of the anaerobic urban wastewater treatment in a submerged hollow-fibre membrane bioreactor at pilot scale

2011

The aim of this study was to assess the effect of several operational variables on both biological and separation process performance in a submerged anaerobic membrane bioreactor pilot plant that treats urban wastewater. The pilot plant is equipped with two industrial hollow-fibre ultrafiltration membrane modules (PURON¿ Koch Membrane Systems, 30m 2 of filtration surface each). It was operated under mesophilic conditions (at 33°C), 70days of SRT, and variable HRT ranging from 20 to 6h. The effects of the influent COD/SO 4-S ratio (ranging from 2 to 12) and the MLTS concentration (ranging from 6 to 22gL -1) were also analysed. The main performance results were about 87% of COD removal, efflu…

The Quest for Twelfth Man: Evidence from Italian Professional Soccer

2008

Impact of organizing working hours (5 shifts of 8 hours per week vs 3 shifts of 12 hours per week) on health and job strain

2015

This article gives an account of research carried out on working hours in a French hospital and specifically the impact on two ways of organizing working hours (12 hour shifts vs 8 hour shifts) on workers health and job strain as perceived by the health care providers. Based on 255 questionnaires, this research indicates that the health care providers who work in 12 hour shifts and 8 hour shifts have the same perception of their health and job strain. However, there are some differences: the health care providers working in 12 hour shifts feel less fatigue and emotional exhaustion than the health care providers working in 8 hour shifts. We discuss these results taking into account that: i) …

Improvement of the thermophilic anaerobic digestion and hygienisation of waste activated sludge by synergistic pretreatment

2019

Hybrid disintegration of waste activated sludge (WAS) before the thermophilic anaerobic stabilization of WAS contributes to the intensification of organic compounds decomposition and increases the effectiveness of the anaerobic stabilization process compared to the fermentation of raw WAS. This article investigates the influence of a chemical-thermal pretreatment procedure with the use of NaOH and freezing by the dry ice on WAS. We found that the hybrid pretreatment of WAS causes higher concentration of released organics in the liquid phase (represented here as a change in soluble chemical oxygen demand - SCOD value) in comparison to these disintegration techniques used separately. The use …

Effects of heat treatment on hydrogen production potential and microbial community of thermophilic compost enrichment cultures

2011

Cellulosic plant and waste materials are potential resources for fermentative hydrogen production. In this study, hydrogen producing, cellulolytic cultures were enriched from compost material at 52, 60 and 70°C. Highest cellulose degradation and highest H(2) yield were 57% and 1.4 mol-H(2) mol-hexose(-1) (2.4 mol-H(2) mol-hexose-degraded(-1)), respectively, obtained at 52°C with the heat-treated (80°C for 20 min) enrichment culture. Heat-treatments as well as the sequential enrichments decreased the diversity of microbial communities. The enrichments contained mainly bacteria from families Thermoanaerobacteriaceae and Clostridiaceae, from which a bacterium closely related to Thermoanaerobiu…

Screening Investments to Reduce the Risk of Hydrologic Failures in the Headwork System Supplying Apulia (Italy) – Role of Economic Evaluation and Ope…

2014

The paper introduces and applies a methodology to screen investments aimed at reducing water supply risks due to hydrologic failures in headwork systems for municipal use, based on the principles of cost-benefit analysis. As risk includes both the probability of a failure and its effect, the methodology combines a simulation module of the system, fed by a stochastic hydrologic input to reproduce the probability distribution of the failures, with a metric for supply failure damage provided by the price – demand relationship for municipal water. Benefits are assessed as the averted damage compared to a base case without investments. This approach is then combined with the classic discounted c…

Wastewater treatment in Valencia city (Spain)

1993

Our objective is to determine the changes in the wastewater treatment process in the city of Valencia by taking into account population changes during the period 1983–1990. We have consulted analytical data and information regarding this volume of water treated in a biological treatment plant of activated sludge; data was collected daily and introduced into a data matrix from which the distribution and central tendency measures were calculated. We then obtained the correlations of the different parameters according to population variations. We observed an increase in the volume of water treated during our study period: from 74,220 m3/day in 1983 to 183,850 m3/day in 1990. This was in contra…

The operating cost of an anaerobic membrane bioreactor (AnMBR) treating sulphate-rich urban wastewater

2014

The objective of this study was to evaluate the operating cost of an anaerobic membrane bioreactor (AnMBR) treating sulphate-rich urban wastewater (UWW) at ambient temperature (ranging from 17 to 33 degrees C). To this aim, energy consumption, methane production, and sludge handling and recycling to land were evaluated. The results revealed that optimising specific gas demand with respect to permeate volume (SGDp) and sludge retention time (for given ambient temperature conditions) is essential to maximise energy savings (minimum energy demand: 0.07 kW h m(-3)). Moreover, low/moderate sludge productions were obtained (minimum value: 0.16 kg TSS kg(-1) CODRemoved), which further enhanced the…