Effects of hydraulic and medium characteristics on solute transfer to surface runoff

1994 ◽  
Vol 30 (7) ◽  
pp. 145-155 ◽  
Author(s):  
J. L. Lai ◽  
S. L. Lo ◽  
C. F. Lin
Keyword(s):  
Mass Loss ◽  
Potassium Chloride ◽  
Surface Runoff ◽  
Relative Length ◽  
Packed Bed ◽  
Rate Of Change ◽  
Solute Transfer ◽  
Factors Affecting ◽  
The Media ◽  
Two Parameters

A two-stage scouring-based model including two parameters for each stage, the ultimate scoured depth and rate of change of scoured depth, was developed to describe solute transfer to surface runoff. While the first stage is a quick decrease of mass loss of solute to surface runoff, the second stage is a slow one. An experimental flume with a medium packed bed was designed. Four different sizes of glass beads were chosen to be the media and saturated with uniform concentration (20000 ppm) of potassium chloride solution before runoff occurred. In a series of experiments, runoff was passed at varied flow rate, velocities, and depths over the medium bed. Runoff samples were taken at the end of flume and the concentration of potassium chloride analysed. By use of this model, the dimensionless ultimate scoured depth and the dimensionless rate of change of each stage were investigated. The results showed that the Reynolds number within media and the relative length were two important factors affecting mass loss of chemicals.

Modelling of Solute Transfer to Surface Runoff

1992 ◽  
Vol 26 (7-8) ◽  
pp. 1851-1856 ◽  
Author(s):  
J. L. Lai ◽  
K. S. L. Lo
Keyword(s):  
Potassium Chloride ◽  
Surface Runoff ◽  
Laboratory Experiments ◽  
Overland Flow ◽  
Chloride Concentration ◽  
Runoff Water ◽  
Mixing Depth ◽  
Change Rate ◽  
Solute Transfer ◽  
The Media

A mixing-based model for describing solute transfer to overland flow was developed. This model included a time-dependent mixing depth of the top layer and a complete-mixed surface runoff zone. In a series of laboratory experiments, runoff was passed at various velocities and depths over a medium bed. The media were saturated with uniform concentration of potassium chloride solution. Runoff water was sampled at the beginning and end of the flume and the potassium chloride concentration analyzed. Using this model, dimensionless ultimate mixing depth and dimensionless change rate of mixing depth from experimental data were investigated and implemented. The results showed that the Reynolds number and relative roughness are two important factors.

Predicting solute transfer to surface runoff using neural networks

1998 ◽  
Vol 38 (10) ◽  
pp. 173-180 ◽  
Author(s):  
Ruei-Shan Lu ◽  
Jiun-Liang Lai ◽  
Shang-Lien Lo
Keyword(s):  
Neural Networks ◽  
Surface Runoff ◽  
Packed Bed ◽  
Flow Rates ◽  
Solute Transfer ◽  
Laboratory Flume ◽  
Series Of Experiments ◽  
Rms Error ◽  
Input Variables ◽  
Hidden Nodes

In this study, a series of experiments were performed in a laboratory flume with a medium-packed bed. Surface runoff was controlled to pass at various flow rates, velocities, and runoff depths over the medium bed. Runoff samples were taken at the end of the flume, and the concentration of potassium chloride was analyzed. The relationships between the controlled input variables and the affected output variables was modeled using artificial neural networks (ANN). Many different ANN-architectures were investigated and this work shows that an optimum architecture with minimum RMS error at five hidden nodes was observed.

scholarly journals Comparison of grape harvesting and sorting methods on factors affecting the must quality

2015 ◽  
Vol 46 (1) ◽  
pp. 19 ◽  
Author(s):  
Alessandro Parenti ◽  
Paolo Spugnoli ◽  
Piernicola Masella ◽  
Lorenzo Guerrini ◽  
Stefano Benedettelli ◽  
...  
Keyword(s):  
Quality Standards ◽  
Wine Quality ◽  
High Quality ◽  
Factors Affecting ◽  
Post Harvest ◽  
Harvesting Technique ◽  
Manual Sorting ◽  
Harvesting Techniques ◽  
Two Parameters

This study compared two harvesting techniques (manual and mechanical) and three grape sorting methods (no sorting, manual, and densimetric) in attempts to obtain high-quality must. The trials were carried out in 2009 and 2010 in Tuscany, Italy. The effectiveness of the harvest-sorting chain was assessed on two parameters. Substandard berries (SSB) is the percentage of berries, which do not meet quality standards that enter the winemaking process, and material other than grape (MOG) is a measure of the cleanliness of the berries entering the process. In the two years the trial was run the grape maturation level was widely different; in 2009 the vintage was more far mature than in 2010. With respect to SSB content and harvesting methods, in 2009 (more mature grapes) hand-picking reduced SSB content, while in 2010 there were no differences between the two harvesting methods. In both years, densimetric sorting reduced SSB content, while there were no significant differences between no sorting and manual sorting. In terms of MOG content, both harvesting and sorting results were inconsistent. In 2009, MOG was lower in mechanically harvested grapes; while in 2010 it was lower in hand-picked grapes. As for sorting methods, in 2009 there were no differences in MOG, while in 2010 mechanical sorting produced better results. Our results question whether the post-harvest sorting techniques used by many estates are effective; particularly as the question has received little attention and no previous research has compared methods. Secondly, our study contributes to the debate on the effects of harvesting technique on wine quality.

scholarly journals Decadal-scale onset and termination of Antarctic ice-mass loss during the last deglaciation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Michael E. Weber ◽  
Nicholas R. Golledge ◽  
Chris J. Fogwill ◽  
Chris S. M. Turney ◽  
Zoë A. Thomas
Keyword(s):  
Mass Loss ◽  
Sea Level Rise ◽  
Sea Level ◽  
Ross Sea ◽  
Ice Sheet ◽  
Rate Of Change ◽  
Last Deglaciation ◽  
Decadal Scale ◽  
Ice Sheet Modeling ◽  
Global Sea Level

AbstractEmerging ice-sheet modeling suggests once initiated, retreat of the Antarctic Ice Sheet (AIS) can continue for centuries. Unfortunately, the short observational record cannot resolve the tipping points, rate of change, and timescale of responses. Iceberg-rafted debris data from Iceberg Alley identify eight retreat phases after the Last Glacial Maximum that each destabilized the AIS within a decade, contributing to global sea-level rise for centuries to a millennium, which subsequently re-stabilized equally rapidly. This dynamic response of the AIS is supported by (i) a West Antarctic blue ice record of ice-elevation drawdown >600 m during three such retreat events related to globally recognized deglacial meltwater pulses, (ii) step-wise retreat up to 400 km across the Ross Sea shelf, (iii) independent ice sheet modeling, and (iv) tipping point analysis. Our findings are consistent with a growing body of evidence suggesting the recent acceleration of AIS mass loss may mark the beginning of a prolonged period of ice sheet retreat and substantial global sea level rise.

scholarly journals Klummen som politisk barometer

1970 ◽  
Author(s):  
Lene Rimestad
Keyword(s):  
Public Sphere ◽  
Private Sphere ◽  
The Public ◽  
Before And After ◽  
The Media ◽  
The Public Sphere ◽  
Two Parameters

Columns generally take up a lot of space in the media. But what can an employed journalist write in his column? How is this particular freedom managed and shaped? In this article the columns written by journalists working for Berlingske Tidende are analyzed. The analysis covers two months before and after substantial changes in the paper in 2003. Two parameters are used in the analysis: Political: Is the column pro-government, anti-government, apolitical or mixed. And what sphere does the column cover: Does the column take place in the private sphere or the public sphere? Finally the changes in the period are discussed. But initially the column as a genre is defined.

scholarly journals COLOR CHANGE — MASS LOSS CORRELATION FOR HEAT-TREATED WOOD

2014 ◽  
Vol 2 ◽  
pp. 345-352 ◽  
Author(s):  
Cristina Marinela Olarescu ◽  
Mihaela Campean
Keyword(s):  
Heat Treatment ◽  
Mass Loss ◽  
Color Change ◽  
Treated Wood ◽  
Untreated Wood ◽  
Cost Effective ◽  
Assessment Procedure ◽  
Mathematical Correlation ◽  
Heat Treated ◽  
Two Parameters

Heat treatment is renowned as the most environmentally friendly process of dimensional stabilization that can be applied to wood, in order to make it suitable for outdoor uses. It also darkens wood color and improves wood durability. The intensity of heat treatment can be appreciated by means of two parameters: the color change occured in wood due to the high temperature, and the mass loss, which is a measure of the degree of thermal degradation. In order to find a mathematical correlation between these two parameters, an experimental study was conducted with four European wood species, which were heat-treated at 180°C and 200ºC, for 1-3 hours, under atmosheric pressure.The paper presents the results concerning the color changes and mass losses recorded for the heat-treated wood samples compared to untreated wood.  For all four species, the dependency between the color change and the mass loss was found to be best described by a logarithmic regression equation with R2 of 0.93 to 0.99 for the soft species (spruce, pine and lime), and R2 of 0.77 for beech. The results of this study envisage to simplify the assessment procedure of the heat treatment efficiency, by only measuring the color – a feature that is both convenient and cost-effective. 

scholarly journals FAKTOR-FAKTOR YANG MEMPENGARUHI PERNIKAHAN DINI REMAJA PUTRI DI DESA SEMETEH MUARA LAKITAN KABUPATEN MUSI RAWAS

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Juliana Widyastuti Wahyuningsih Juliana Widyastuti Wahyuningsih
Keyword(s):  
Health Education ◽  
Young People ◽  
Reproductive Health ◽  
Young Women ◽  
Junior High Schools ◽  
Early Marriage ◽  
Factors Affecting ◽  
Reproductive Health Education ◽  
The Media ◽  
Married Students

Pernikahan dini adalah pernikahan yang dilakukan seorang wanita pada usia 13 – 16 tahun atau pria berusia 17 – 18 tahun (BKKBN,2016). Menurut Laporan Badan Pusat Statistik, 2015 menunjukkan bahwa prevalensi perkawinan usia anak di Indonesia tidak hanya tetap tinggi (dengan lebih dari seperenam anak perempuan menikah sebelum mencapai usia dewasa (usia 18 tahun) atau sekitar 340.000 anak perempuan setiap tahunnya) tetapi prevalensi tersebut juga telah kembali meningkat. Tujuan dari penelitian ini adalah Mengetahui gambaran faktor – Faktor yang mempengaruhi Pernikahan dini Remaja Putri di Desa Semeteh Kecamatan Muara Lakitan Kabupaten Musi Rawas. Penelitian ini dilakukan secara kualitatif di Wilayah Desa Semeteh Muara Lakitan Kabupaten Musi Rawas.dengan jumlah responden 5 orang dari jumlah sampel 11 orang. Hasil penelitian menggambarkan bahwa pernikahan dini dilakukan oleh mereka yang berpendidikan SD atau SLTP, dan berpengetahuan cukup. Pernikahan dini dianggap sesuatu hal yang lazim dan menurunkan tanggung jawab ekonomi orang tua. Selain itu media punya andil terjadinya pernikahan dini. Penelitian ini diharapkan dapat bermanfaat bagi pasangan remaja calon pengantin, mahasiswa dan institusi profesi kebidanan khususnya dalam memberikan pendidikan kesehatan reproduksi remaja terkait dengan masalah pernikahan dini.     ABSTRACK   Early marriage is a marriage made by a woman at the age of 13-16 years or a man aged 17-18 years (BKKBN, 2016). According to the Central Bureau of Statistics Report, 2015 shows that the prevalence of marriage in Indonesian age is not only high (with more than one-sixth married girls before reaching adulthood (age 18) or about 340,000 girls annually) but the prevalence has also returned increased. The purpose of this study is to know the description of factors - Factors affecting early marriage of Young Women in the Semeteh Village Muara Lakitan Musi Rawas District. This study was conducted qualitatively in Semeteh Village, Muara Lakitan, Musi Rawas District with 5 people as the respondents of the 11 samples. The results of the study indicated that the early marriage was conducted by people who had educated in elementary or junior high schools, and had  sufficient knowledge. Early marriage was considered as a usual something and could  decrease economic responsibility of their parents. In addition, the media had contributed to the incidence of early marriages. This study is expected to be useful for couples of young people who will get to be married, students and midwifery profession institutions  particularly in providing reproductive health education for the adolescences in accordance with the early marriage.  

Use of a simple model to study factors affecting the size distribution of tubers in potato crops

1987 ◽  
Vol 109 (3) ◽  
pp. 563-571 ◽  
Author(s):  
K. Z. Travis
Keyword(s):  
Mathematical Model ◽  
Size Distribution ◽  
Field Experiments ◽  
Tuber Yield ◽  
Tuber Size ◽  
Simple Mathematical Model ◽  
Factors Affecting ◽  
Tuber Size Distribution ◽  
Two Parameters ◽  
Potato Crops

SummaryA simple mathematical model of the distribution of potato tuber yield between size grades is presented. It has two parameters, μ, a measure of crop tuber size and σ, a measure of the spread of yield across size grades. The model is shown to be useful for the analysis of field experiments, the prediction and physiological study of tuber size distribution, and the economic analysis of management decisions. The model is applied to a variety of dataandthe practical control of tuber size discussed.

Correcting for Selection Bias in Social Movement Research

1998 ◽  
Vol 3 (2) ◽  
pp. 141-161 ◽  
Author(s):  
Simon Hug ◽  
Dominique Wisler
Keyword(s):  
Social Movement ◽  
Selection Bias ◽  
Truncated Regression ◽  
Factors Affecting ◽  
Local Newspapers ◽  
Data Analyses ◽  
Regression Approach ◽  
Scant Attention ◽  
The Media ◽  
Cross National

Longitudinal and cross-national research on new social movements often relies on newspaper reports for data on the frequency and type of events. Reporting by newspapers is, however, known to be strongly affected by selection bias. Newspapers report events that they find "newsworthy." Surprisingly, the effect of these selection biases on data analyses has received scant attention, and the methodology to correct for these biases hardly has been discussed. Based on data covering events in four cities in Switzerland we propose two types of corrections for the selection bias. The first is based on a simple weighting scheme for events reported in local newspapers. These weights are likely to provide useful corrections even in other contexts. The second correction attempts to model explicitly the selection bias of the media. This truncated regression approach is shown to be a useful strategy when the selectivity by the newspapers is severe, and the factors affecting this selection are largely known.

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