scholarly journals STUDY OF THE OPERATING MODES OF DRAINAGE LAYERS IN ROAD CONSTRUCTION

2020 ◽  
pp. 24-29
Author(s):  
Бубела А. В. ◽  
Кватадзе А. І.
Keyword(s):  
Working Conditions ◽  
Water Discharge ◽  
Road Construction ◽  
Sand Layer ◽  
Short Term ◽  
Withdrawal Time ◽  
Operating Modes ◽  
Gravel Layer ◽  
Drainage Layers

The work presents the study of working conditions of draining layers with crushed fraction 20 – 40 mm, and with medium grained sand in complex with tubular transverse shallow drainage. Investigations have been carried out on the construction of a road structure, the dimensions of which correspond to the field conditions. Investigations measured the amount of drained water from the trench and the time it was drained. On the basis of the results obtained, the operating modes of the drainage structures are determined, which depends on the properties of the fillers and the withdrawal time. Both types of construction are divided into short-term and long-term modes in terms of water discharge intensity. According to these regimes, the average discharge intensity of each type of drainage structure was determined and differed significantly. The work of two drainage structures was also analyzed: the drainage structure with the gravel layer worked on the drainage principle, as opposed to the drainage structure with the sand layer - on the absorption principle.

scholarly journals An Efficient Prediction Model for Water Discharge in Schoharie Creek, NY

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Katerina G. Tsakiri ◽  
Antonios E. Marsellos ◽  
Igor G. Zurbenko
Keyword(s):  
New York ◽  
Time Series ◽  
Water Discharge ◽  
Winter Period ◽  
Statistical Methodology ◽  
Summer Period ◽  
Short Term ◽  
Efficient Prediction ◽  
Climatic Time Series

Flooding normally occurs during periods of excessive precipitation or thawing in the winter period (ice jam). Flooding is typically accompanied by an increase in river discharge. This paper presents a statistical model for the prediction and explanation of the water discharge time series using an example from the Schoharie Creek, New York (one of the principal tributaries of the Mohawk River). It is developed with a view to wider application in similar water basins. In this study a statistical methodology for the decomposition of the time series is used. The Kolmogorov-Zurbenko filter is used for the decomposition of the hydrological and climatic time series into the seasonal and the long and the short term component. We analyze the time series of the water discharge by using a summer and a winter model. The explanation of the water discharge has been improved up to 81%. The results show that as water discharge increases in the long term then the water table replenishes, and in the seasonal term it depletes. In the short term, the groundwater drops during the winter period, and it rises during the summer period. This methodology can be applied for the prediction of the water discharge at multiple sites.

Preliminary Evaluation of Visibility in Hazardous Materials Level a Suit

2002 ◽  
Vol 46 (13) ◽  
pp. 1220-1223
Author(s):  
John P. Holmquist ◽  
Par Östberg ◽  
Pär Axelsson ◽  
Nino Gallini ◽  
Mike Landsberger
Keyword(s):  
Working Conditions ◽  
Hazardous Materials ◽  
Initial Evaluation ◽  
Preliminary Evaluation ◽  
Short Term ◽  
Moisture Barrier ◽  
Moisture Barriers

This paper evaluated the problem of visibility of a hazardous materials (hazmat) responder while wearing a level A hazmat suit. An experiment was performed to judge the amount of time a level A hazmat suit can be worn in normal working conditions without fogging and reducing visibility. After an initial evaluation, hypothesis and alternatives to prevent the fogging of the suit were formed. An experiment was performed testing the alternatives of antifogging agents to physical moisture barriers. From the experiment, a short-term solution, the use of anti-fog spray, and a long-term solution, the use of a cone shaped moisture barrier, were formed to correct the visibility problem facing the users of this suit.

scholarly journals Favourable changes in physical working conditions and the risk of all-cause sickness absence: a pseudo-experiment

2019 ◽  
Vol 30 (2) ◽  
pp. 253-259
Author(s):  
Rahman Shiri ◽  
Aapo Hiilamo ◽  
Olli Pietiläinen ◽  
Minna Mänty ◽  
Ossi Rahkonen ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Sickness Absence ◽  
Working Conditions ◽  
Negative Binomial ◽  
Physical Workload ◽  
Health Study ◽  
Baseline Survey ◽  
Short Term

Abstract Background We determined whether favourable changes in physical workload and environmental factors reduce sickness absence (SA) days using observational cohort data as a pseudo-experiment. Methods The data from the Finnish Helsinki Health Study included three cohorts of employees of the City of Helsinki [2000/2002–07 (N = 2927), 2007–12 (N = 1686) and 2012–17 (N = 1118), altogether 5731 observations]. First, we estimated the propensity score of favourable changes (reduction in exposures) in physical workload and environmental factors during each 5-year follow-up period on the baseline survey characteristics using logistic regression. Second, we created and stabilized inverse probability of treatment weights for each participant using the propensity scores. Lastly, we used generalized linear model and fitted negative binomial regression models for over-dispersed count data to estimate whether the favourable changes decrease the risk of short-term (1–3 days), intermediate-term (4–14 days) and long-term (>14 days) SA using employer’s register data. Results During a 5-year follow-up, 11% of the participants had favourable changes in physical workload factors, 13% in environmental factors and 8% in both factors. The incidence of short-term, intermediate-term and long-term SA were lower in employees with favourable workplace changes compared with those without such changes. The reductions were largest for long-term SA. Reporting favourable changes in both workload and environmental factors reduced the number of SA days by 41% within 1 year after the changes and by 32% within 2 years after the changes. Conclusion This pseudo-experimental study suggests that improving physical working conditions reduces SA.

scholarly journals Mental Health Before and After Retirement—Assessing the Relevance of Psychosocial Working Conditions: The Whitehall II Prospective Study of British Civil Servants

2019 ◽  
Vol 75 (2) ◽  
pp. 403-413 ◽  
Author(s):  
Maria Fleischmann ◽  
Baowen Xue ◽  
Jenny Head
Keyword(s):  
Mental Health ◽  
Social Support ◽  
Working Conditions ◽  
Job Demands ◽  
Short Term ◽  
Psychosocial Working Conditions ◽  
Decision Authority ◽  
Long Term Changes ◽  
Work Social Support

Abstract Objectives Retirement could be a stressor or a relief. We stratify according to previous psychosocial working conditions to identify short-term and long-term changes in mental health. Method Using data from the Whitehall II study on British civil servants who retired during follow-up (n = 4,751), we observe mental health (General Health Questionnaire [GHQ] score) on average 8.2 times per participant, spanning up 37 years. We differentiate short-term (0–3 years) and long-term (4+ years) changes in mental health according to retirement and investigate whether trajectories differ by psychosocial job demands, work social support, decision authority, and skill discretion. Results Each year, mental health slightly improved before retirement (−0.070; 95% CI [−0.080, −0.059]; higher values on the GHQ score are indicative of worse mental health), and retirees experienced a steep short-term improvement in mental health after retirement (−0.253; 95% CI [−0.302, −0.205]), but no further significant long-term changes (0.017; 95% CI [−0.001, 0.035]). Changes in mental health were more explicit when retiring from poorer working conditions; this is higher psychosocial job demands, lower decision authority, or lower work social support. Discussion Retirement was generally beneficial for health. The association between retirement and mental health was dependent on the context individuals retire from.

scholarly journals Handling Solution Tidal Flood in Kaligawe Area by Polder System Drainage

2019 ◽  
Vol 9 (2) ◽  
pp. 1104-1109
Keyword(s):  
Field Survey ◽  
Water Discharge ◽  
Secondary Data ◽  
Water Levels ◽  
Medium Term ◽  
Short Term ◽  
Tidal Elevation ◽  
Institutional Management ◽  
Tidal Movement

Kaligawe area is one of the main routes of North Java Coastal traffic and also the gateway of Semarang city from the east. Since more than 5 years this area proned by flooding due to a combination of land subsidence, increasing influence by tidal movement from sea the inability of free flow discharge of river water. In periods of flooding long traffic jams occur for more than 10 kilometers in length. The purpose of this research is to map the flood problem in Kaligawe area, identify the causes of flooding, analyze the technical handling solution and formulate the measures to prevent the flooding in this region. The research method is based on detailed field survey, measurement and observations of water levels, secondary data collection that consist of land subsidence’s, rainfall intensities, tidal elevation. The data are analyzed qualitatively and quantitatively. Among the results of this study is to formulate measures to prevent the number and degree of flooding. These measures can be divided in short, medium term and long term stages. The short term measures consist of construct a temporary weir to regulate water discharge and pump installation including pump strategy. The medium term stage consists of making a polder system, the long term stage consists of spatial sustainability and institutional management of Operation and Maintenance of Polder system.

scholarly journals Investigation of the thermal state of the elements of a technological electron beam gun under long–term operating conditions

2021 ◽  
Vol 2077 (1) ◽  
pp. 012008
Author(s):  
I A Kharitonov ◽  
A L Goncharov ◽  
E K Titarev ◽  
A V Nekhoroshev
Keyword(s):  
Thermal State ◽  
Critical Value ◽  
Operating Conditions ◽  
Electron Gun ◽  
Short Term ◽  
Operating Modes ◽  
Cathode Assembly ◽  
Forced Cooling ◽  
The Mathematical Model

Abstract The paper presents the results of a study of the thermal state of the elements of the cathode assembly of the ELA–15 welding electron gun. It was revealed that in short–term operating modes of the gun (up to 60 minutes) at any energy parameters of heating the hexaboride cathode, it is possible not to use forced cooling of the cathode assembly. The case temperature in such modes did not exceed 30°C. The increase in the temperature of the gun body occurred 15 minutes after the start of heating the cathode. In long–term operating modes with forced cooling of the gun, the temperature of the gun body increased by 2 – 3°C and remained stable throughout the operation. When the cooling was turned off, the temperature of the gun body reached a critical value in 60 minutes. The section of natural cooling of the cathode obtained in the work, which appears when the heating of the cathode is stopped, is well approximated by a power function. It is convenient to use this dependence to verify the mathematical model of the thermal state of the electron gun.

Work environment risk factors for the duration of all cause and diagnose-specific sickness absence among healthcare workers in Sweden: a prospective study

2020 ◽  
Vol 77 (11) ◽  
pp. 782-789
Author(s):  
Constanze Leineweber ◽  
Staffan Marklund ◽  
Klas Gustafsson ◽  
Magnus Helgesson
Keyword(s):  
Work Environment ◽  
Sickness Absence ◽  
Working Conditions ◽  
Healthcare Workers ◽  
Job Control ◽  
Psychiatric Diagnoses ◽  
Short Term ◽  
Job Support ◽  
The Impact

ObjectivesIncreasing sickness absence (SA) has been reported among healthcare workers in Sweden. Our aim was to analyse the impact of work environment factors on short-term and long-term SA based on musculoskeletal and psychiatric diagnoses among healthcare workers.MethodsThe study sample consisted of healthcare workers (n=12 452) drawn from representative samples of workers aged 16 to 64, who participated in the Swedish Work Environment Surveys (SWES) between 1993 and 2013. The outcomes were either short-term (≤28 days) or long-term (>104 days) SA between 1994 and 2016. HRs and 95% CIs were calculated for the impact of physical and psychosocial working conditions on risk of subsequent short-term or long-term SA for 3 years after participation in SWES.ResultsHeavy physical work and strenuous work postures showed elevated HRs for short-term and long-term SA compared with those without these work exposures. Similarly, high job demands and low job control each increased the risk for both short-term and long-term SA compared with employees with low job demands and high job control. Low job support increased the risk for short-term SA compared with those with high job support. Working conditions were strongly related to short-term SA due to musculoskeletal diagnoses but not to short-term SA due to psychiatric diagnoses. None of the work characteristics, except strenuous postures, elevated the risk for long-term SA due to psychiatric diagnosis compared with employees without these characteristics.ConclusionsErgonomic improvements and stress reduction among healthcare workers are likely to reduce the prevalence of SA foremost due to musculoskeletal diagnoses.

Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter
Keyword(s):  
Working Memory ◽  
Rapid Serial Visual Presentation ◽  
Language Comprehension ◽  
Short Term Memory ◽  
Visual Presentation ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

1990 ◽  
Vol 48 (3) ◽  
pp. 374-375
Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson
Keyword(s):  
Antidepressant Drug ◽  
Beagle Dogs ◽  
Long Term Effects ◽  
Short Term ◽  
Platelet Counts ◽  
Toxicological Studies ◽  
Induced Aggregation ◽  
Internal Architecture

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.

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