Swine Finishing Room Air Infiltration: Part 2. Infiltration as Affected by Room Characteristics

2018 ◽  
Vol 34 (4) ◽  
pp. 735-745
Author(s):  
Harishchandra T Jadhav ◽  
Steven J Hoff ◽  
Jay D Harmon ◽  
Daniel S Andersen
Keyword(s):  
Linear Regression ◽  
Power Law ◽  
Infiltration Rate ◽  
The United States ◽  
Design Criterion ◽  
Large Variability ◽  
Infiltration Rates ◽  
Air Infiltration ◽  
Ceiling Height ◽  
The Relationship

Abstract. Data collected on 17 swine finishing rooms from the Midwest region of the United States was used to study the relationship between infiltration rate and selected room characteristics. Effect of individual room characteristics on room infiltration rate were tested by simple linear regression (SLR) while multiple linear regression (MLR) was used to develop models for improved prediction. SLR results revealed that the total (It) and other (Io; non-curtain/fan locations) swine finishing room infiltration rates were inversely related to room width and directly related to room length and ceiling height. As expected, rooms with higher curtain end pocket overlap, curtain closure overlap distance, and in excellent condition had reduced curtain infiltration (Ic). To reduce fan infiltration (If), fan and pump-out cover perimeter and fan area should be minimized. Power law equations fitted for groups of rooms were found ineffective in accounting for the large variability in infiltration rates of swine finishing rooms as compared to MLR models. MLR models developed for It and Io prediction at 10, 20, and 30 Pa pressure differences were found to improve the prediction over power law models for groups of rooms. At 20 Pa, prediction differences compared with individual room measurements for It rate using the suggested MLR model, as compared to power law models for groups of rooms, were less by at least 61%; whereas, in the case of Io rate, prediction differences compared with individual room measurements were less by at least 49%. Recommendations made in this article, with respect to the relationship between a particular room characteristic and room infiltration rate, could be used as guiding principles along with other design criterion to reduce infiltration rates in remodeled and new swine finishing rooms. Keywords: Infiltration, Swine finishing rooms, Ventilation.

scholarly journals Swine Finishing Room Air Infiltration: Part 1. Quantification and Prediction

2018 ◽  
Vol 34 (2) ◽  
pp. 413-424
Author(s):  
H T Jadhav ◽  
S J Hoff ◽  
J D Harmon ◽  
Igancio Alvarez ◽  
D S Andersen ◽  
...  
Keyword(s):  
Sea Level ◽  
Power Law ◽  
Pressure Difference ◽  
Construction Material ◽  
Weather Conditions ◽  
Infiltration Rate ◽  
Mechanically Ventilated ◽  
Infiltration Rates ◽  
Air Infiltration ◽  
Single Room

Abstract. Air infiltration through unplanned inlets is an integral component of any ventilation process. Air infiltration affects the quality of the room environment and can also increase winter heating costs. Precise data on air infiltration is very important in the design of animal room ventilation systems. Nineteen mechanically ventilated (negative pressure type) swine finishing rooms in Iowa were tested for their air infiltration potential. Using the data of 17 rooms, air infiltration rate through the whole room (i.e., total air infiltration, It), curtains (Ic), fans (If), and net building shell (other components, Io) were quantified. Power law equations were developed for infiltration prediction of different room configurations grouped on the basis of their construction style, age, ceiling material, curtain perimeter, and fan backdraft shutter area. All power law models reported in this study were adjusted to predict standard (sea level) infiltration rates. At 20 Pa pressure difference across the room envelope, the predicted standard It infiltration rate for the 17 rooms was 5.96±1.49 air changes per hour (ach); whereas, the predicted standard Ic, If, and Io infiltration rates were 1.49 ±1.00 ach (about 25% of It), 1.52 ±1.38 ach (about 26% of It) and 2.90 ±1.42 ach (about 49% of It), respectively. The standard It infiltration rate trended lower for rooms (n=8) from single room layout barns (5.85 ±1.66 at 20 Pa), rooms (n=8) having a non-metal ceiling (5.85 ±2.15 at 20 Pa), and rooms (n=8) aged = 13 years (5.85 ±2.15 at 20 Pa). The infiltration resistances, calculated using standard sea level infiltration rates, indicated that the curtain, fan, and other infiltration areas of swine finishing rooms changes with barn layout, age, construction material, and pressure difference. Methodology to convert measured infiltration rates to standard sea level weather conditions and to any desired room location was included. Keywords: Infiltration, Swine finishing Barns, Swine finishing rooms, Infiltration prediction, Infiltration quantification, Ventilation.

scholarly journals Logarithmic transformation and peak-discharge power-law analysis

2019 ◽  
Vol 51 (1) ◽  
pp. 65-76
Author(s):  
Bo Chen ◽  
Chunying Ma ◽  
Witold F. Krajewski ◽  
Pei Wang ◽  
Feipeng Ren
Keyword(s):  
Linear Regression ◽  
Power Law ◽  
Nonlinear Regression ◽  
The United States ◽  
Logarithmic Transformation ◽  
Peak Discharge ◽  
Discharge Power ◽  
Flood Frequency Analysis ◽  
Scaling Parameters ◽  
Log Linear

Abstract The peak-discharge and drainage area power-law relation has been widely used in regional flood frequency analysis for more than a century. The coefficients and can be obtained by nonlinear or log-log linear regression. To illustrate the deficiencies of applying log-transformation in peak-discharge power-law analyses, we studied 52 peak-discharge events observed in the Iowa River Basin in the United States from 2002 to 2013. The results show that: (1) the estimated scaling exponents by the two methods are remarkably different; (2) for more than 80% of the cases, the power-law relationships obtained by log-log linear regression produce larger prediction errors of peak discharge in the arithmetic scale than that predicted by nonlinear regression; and (3) logarithmic transformation often fails to stabilize residuals in the arithmetic domain, it assigns higher weight to data points representing smaller peak discharges and drainage areas, and it alters the visual appearance of the scatter in the data. The notable discrepancies in the scaling parameters estimated by the two methods and the undesirable consequences of logarithmic transformation raise caution. When conducting peak-discharge scaling analysis, especially for prediction purposes, applying nonlinear regression on the arithmetic scale to estimate the scaling parameters is a better alternative.

scholarly journals Aerobic Fitness and Cognition Changes After Exercise Training in Alzheimer's Disease

2017 ◽  
Vol 6 (2) ◽  
pp. 22-28
Author(s):  
Dereck L. Salisbury ◽  
Fang Yu
Keyword(s):  
Alzheimer’S Disease ◽  
Older Adults ◽  
Alzheimer's Disease ◽  
Linear Regression ◽  
Exercise Training ◽  
Aerobic Fitness ◽  
Repeated Measures ◽  
The United States ◽  
Community Dwelling ◽  
The Relationship

Background: Alzheimer's disease (AD) currently affects 5.4 million Americans and is the sixth leading cause of death in the United States. The mechanism of exercise-induced brain adaptations are not fully understood, but enhanced aerobic fitness has been postulated as an essential physiological mechanism and is beginning to be studied. The purpose of this analysis was to examine the relationship between changes in aerobic fitness and cognition following 6 months of aerobic exercise training in older adults with AD. Methods: Twenty-seven community-dwelling older adults with mild to moderate AD completed a 6-month, 3 times per week, moderate-vigorous intensity cycling exercise program in 2 identical studies using a single-group repeated-measures designs. AD symptoms were measured with the AD Assessment Scale–cognitive subscale (ADAS-cog), while aerobic fitness was assessed by the intermittent shuttle walk test (ISWT) at baseline and 6 months. Pearson's correlation coefficient tests and linear regression were used to assess the relationship between changes in aerobic fitness and cognition. Results: Adjusted for age, the 6-month change in ISWT distance had an inverse relationship with the 6-month change in ADAS-Cog (r = −0.49; P = .01), indicating that enhanced aerobic fitness was associated with improved cognitive changes. Linear regression was statistically significant when adjusted by age (F([2,14] =5.33, P =.01, R2 = .31). Conclusion: Enhanced aerobic fitness may attenuate cognitive decline in persons with mild to moderate AD.

scholarly journals Evaluating methods for estimating whole house air infiltration rates in summer: implications for overheating and indoor air quality

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ben M. Roberts ◽  
David Allinson ◽  
Kevin J. Lomas
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Infiltration Rate ◽  
Estimation Methods ◽  
Tracer Gas ◽  
Content Type ◽  
Infiltration Rates ◽  
Air Infiltration ◽  
Fan Pressurisation

PurposeAccurate values for infiltration rate are important to reliably estimate heat losses from buildings. Infiltration rate is rarely measured directly, and instead is usually estimated using algorithms or data from fan pressurisation tests. However, there is growing evidence that the commonly used methods for estimating infiltration rate are inaccurate in UK dwellings. Furthermore, most prior research was conducted during the winter season or relies on single measurements in each dwelling. Infiltration rates also affect the likelihood and severity of summertime overheating. The purpose of this work is to measure infiltration rates in summer, to compare this to different infiltration estimation methods, and to quantify the differences.Design/methodology/approachFifteen whole house tracer gas tests were undertaken in the same test house during spring and summer to measure the whole building infiltration rate. Eleven infiltration estimation methods were used to predict infiltration rate, and these were compared to the measured values. Most, but not all, infiltration estimation methods relied on data from fan pressurisation (blower door) tests. A further four tracer gas tests were also done with trickle vents open to allow for comment on indoor air quality, but not compared to infiltration estimation methods.FindingsThe eleven estimation methods predicted infiltration rates between 64 and 208% higher than measured. The ASHRAE Enhanced derived infiltration rate (0.41 ach) was closest to the measured value of 0.25 ach, but still significantly different. The infiltration rate predicted by the “divide-by-20” rule of thumb, which is commonly used in the UK, was second furthest from the measured value at 0.73 ach. Indoor air quality is likely to be unsatisfactory in summer when windows are closed, even if trickle vents are open.Practical implicationsThe findings have implications for those using dynamic thermal modelling to predict summertime overheating who, in the absence of a directly measured value for infiltration rate (i.e. by tracer gas), currently commonly use infiltration estimation methods such as the “divide-by-20” rule. Therefore, infiltration may be overestimated resulting in overheating risk and indoor air quality being incorrectly predicted.Originality/valueDirect measurement of air infiltration rate is rare, especially multiple tests in a single home. Past measurements have invariably focused on the winter heating season. This work is original in that the tracer gas technique used to measure infiltration rate many times in a single dwelling during the summer. This work is also original in that it quantifies both the infiltration rate and its variability, and compares these to values produced by eleven infiltration estimation methods.

scholarly journals Home Energy Efficiency and Subjective Health in Greater London

2021 ◽  
Author(s):  
P. Symonds ◽  
N. Verschoor ◽  
Z. Chalabi ◽  
J. Taylor ◽  
M. Davies
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Positive Association ◽  
Significant Positive Association ◽  
Health And Wellbeing ◽  
Infiltration Rates ◽  
Air Infiltration ◽  
Reported Health ◽  
The Uk ◽  
The Relationship

AbstractThe UK has introduced legislation that requires net-zero greenhouse gas emissions to be achieved by 2050. Improving the energy efficiency of homes is a key objective to help reach this target, and the UK government’s Clean Growth Strategy aims to get many homes up to an Energy Performance Certificate (EPC) Band of C by 2035. The relationship between home energy-efficiency and occupant health and wellbeing remains an area of ongoing research. This paper explores the nexus between home energy efficiency, energy consumption and self-reported health—an indicator of the general health and wellbeing of the population. We focus on Greater London through secondary data analysis. Energy-efficiency ratings and air infiltration rates of dwellings, derived from EPCs, were aggregated and matched to local area self-reported health and energy consumption data obtained from the Greater London Authority’s (GLA) Lower Layer Super Output Area (LSOA) Atlas database. Our regression model indicates that improving the energy efficiency (SAP) rating by 10 points for a typical home may reduce household gas consumption by around 7% (95% CIs: 2%, 14%). Beta regression finds a positive, but not statistically significant association between median SAP rating and the proportion of the population reporting ‘good or very good’ health when considering all Greater London LSOAs (z score = 0.60, p value = 0.55). A statistically significant positive association is observed however when repeating the analysis for the lowest income quartile LSOAs (z score = 2.03, p value = 0.04). This indicates that the least well-off may benefit most from home energy efficiency programs. A statistically significant positive association is also observed for the relationship between self-reported health and air infiltration rates (z score = 2.62, p value = 0.01). The findings support existing evidence for the predominantly naturally ventilated UK housing stock, suggesting that home energy efficiency measures provide a co-benefit for occupant health provided that adequate air exchange is maintained.

Potential impact of Faidherbia albida tree on soil infiltration in a semi-arid agroforestry system of the Senegalese groundnut basin: role of preferential flows? 

2021 ◽  
Author(s):  
Waly Faye ◽  
Didier Orange ◽  
Djim Mouhamadou Lamine Diongue ◽  
Frederic Do ◽  
Christophe Jourdan ◽  
...  
Keyword(s):  
Bulk Density ◽  
Hydraulic Properties ◽  
Sandy Soils ◽  
Infiltration Rate ◽  
Water Infiltration ◽  
Clay Soils ◽  
Faidherbia Albida ◽  
Large Variability ◽  
Infiltration Rates ◽  
Single Ring

<p>The soil hydraulic properties controlling infiltration are dynamic depending on interrelated factors such as soil texture and structure, climate (rainfall intensity), land use, vegetation cover and plant root systems. These physical and biological factors directly influence the size and geometry of the conductive pores, and therefore the bulk density, soil structure and finally water infiltration at surface. In the Sahelian zone, the slightest modification of the physical properties of the soil has severe consequences on the soil properties and thus on hydrological processes. It is therefore essential to improve knowledge on the spatial distribution of the hydraulic behavior of soils for optimization of agricultural uses.</p><p>We used the BEST method (Beerkan Estimation of Soil Transfer parameters) on a toposequence of the Senegalese groundnut basin (Fatick region) in the Faidherbia-Flux observatory[1] where the average rainfall is 590 mm/yr. The studied toposequence (400 m long) is representative of a common agroforestry zone with annual cultivation of millet and peanuts and a sparse density of Faidherbia albida. The slope is low (1%) with small lowland areas made up of sandy soil with more clay (clay soil), while the glacis is represented by more or less compacted sand. The infiltrometry measurements were made with the automatic single-ring infiltrometer developed by Di Prima et al. (2016), used here for the first time in West Africa. The explicative variables tested are the type of soils, including: clay soils under tree (CLUT) and outside tree (CLOT), sandy soils under tree (SSUT) and outside trees (SSOT), and cattle trampled soils outside trees (TSOT) particularly compacted and largely present in the study area. BEST algorithms were applied to the experimental data to determine the hydraulic properties of the soils of the different variables and to draw water retention and hydraulic conductivity curves.</p><p>There are significant differences in infiltration rates between the sampled zones and in relation with the studied factors. The highest infiltration rate is found on sandy soils under tree (SSUT) with an average infiltration rate of 14.0 mm/min, followed by SSOT with 11.6 mm/min. Then the clay soils CLUT and CLOT are characterized by similar lower hydraulic responses with average infiltration rates of 6.9 mm/min and 6.2 mm/min, respectively. The average infiltration rate is the lowest on the compacted sandy soils TSOT, with only 5.4 mm/min. The study of the variability of the infiltration rates measured by class of variable shows a large variability for CLOT, CLUT and SSUT (decreasing order of variability). These results are in agreement with the measured values of dry soil bulk density. The high infiltration rates in the clay soils outside and under trees can be explained by the higher content of organic matter observed on the sampling, and probably by the existence of preferential flow activated by the macropores particularly present on clay soils (CLOT and CLUT) and on sandy soils under tree (SSUT).</p><p>Di Prima, S., et al., 2016. Testing a new automated single ring infiltrometer for Beerkan infiltration experiments. Geoderma, 262, 20–34. doi:10.1016/j.geoderma.2015.08.006</p><div> <div> <p>[1] Faidherbia-Flux : https://lped.info/wikiObsSN/?Faidherbia-Flux</p> </div> </div><p> </p>

Abusive Men's Use of Children to Control Their Partners and Ex-Partners

2007 ◽  
Vol 12 (1) ◽  
pp. 54-61 ◽  
Author(s):  
Marisa L. Beeble ◽  
Deborah Bybee ◽  
Cris M. Sullivan
Keyword(s):  
United States ◽  
Intimate Partner Violence ◽  
Partner Violence ◽  
Emotional Abuse ◽  
The United States ◽  
Intimate Partner ◽  
Anecdotal Evidence ◽  
Multiple Variables ◽  
The Relationship

While research has found that millions of children in the United States are exposed to their mothers being battered, and that many are themselves abused as well, little is known about the ways in which children are used by abusers to manipulate or harm their mothers. Anecdotal evidence suggests that perpetrators use children in a variety of ways to control and harm women; however, no studies to date have empirically examined the extent of this occurring. Therefore, the current study examined the extent to which survivors of abuse experienced this, as well as the conditions under which it occurred. Interviews were conducted with 156 women who had experienced recent intimate partner violence. Each of these women had at least one child between the ages of 5 and 12. Most women (88%) reported that their assailants had used their children against them in varying ways. Multiple variables were found to be related to this occurring, including the relationship between the assailant and the children, the extent of physical and emotional abuse used by the abuser against the woman, and the assailant's court-ordered visitation status. Findings point toward the complex situational conditions by which assailants use the children of their partners or ex-partners to continue the abuse, and the need for a great deal more research in this area.

The United States and the Iranian Nuclear Programme

2018 ◽  
Author(s):  
Steven Hurst
Keyword(s):  
United States ◽  
Decision Making ◽  
Domestic Politics ◽  
The United States ◽  
Nixon Administration ◽  
Comprehensive Plan ◽  
The Us ◽  
Nuclear Issue ◽  
The Relationship

The United States, Iran and the Bomb provides the first comprehensive analysis of the US-Iranian nuclear relationship from its origins through to the signing of the Joint Comprehensive Plan of Action (JCPOA) in 2015. Starting with the Nixon administration in the 1970s, it analyses the policies of successive US administrations toward the Iranian nuclear programme. Emphasizing the centrality of domestic politics to decision-making on both sides, it offers both an explanation of the evolution of the relationship and a critique of successive US administrations' efforts to halt the Iranian nuclear programme, with neither coercive measures nor inducements effectively applied. The book further argues that factional politics inside Iran played a crucial role in Iranian nuclear decision-making and that American policy tended to reinforce the position of Iranian hardliners and undermine that of those who were prepared to compromise on the nuclear issue. In the final chapter it demonstrates how President Obama's alterations to American strategy, accompanied by shifts in Iranian domestic politics, finally brought about the signing of the JCPOA in 2015.

Confluencia geopolítica entre Cárdenas y Roosevelt:

2019 ◽  
Vol 35 (2) ◽  
pp. 231-254
Author(s):  
Andreu Espasa
Keyword(s):  
World War Ii ◽  
New Deal ◽  
Spanish Civil War ◽  
The United States ◽  
Political Crisis ◽  
World War ◽  
Military Alliance ◽  
Bilateral Relations ◽  
The Relationship ◽  
The New Deal

De forma un tanto paradójica, a finales de los años treinta, las relaciones entre México y Estados Unidos sufrieron uno de los momentos de máxima tensión, para pasar, a continuación, a experimentar una notable mejoría, alcanzando el cénit en la alianza política y militar sellada durante la Segunda Guerra Mundial. El episodio catalizador de la tensión y posterior reconciliación fue, sin duda, el conflicto diplomático planteado tras la nacionalización petrolera de 1938. De entre los factores que propiciaron la solución pacífica y negociada al conflicto petrolero, el presente artículo se centra en analizar dos fenómenos del momento. En primer lugar, siguiendo un orden de relevancia, se examina el papel que tuvo la Guerra Civil Española. Aunque las posturas de ambos gobiernos ante el conflicto español fueron sustancialmente distintas, las interpretaciones y las lecciones sobre sus posibles consecuencias permitieron un mayor entendimiento entre los dos países vecinos. En segundo lugar, también se analizarán las afinidades ideológicas entre el New Deal y el cardenismo en el contexto de la crisis mundial económica y política de los años treinta, con el fin de entender su papel lubricante en las relaciones bilaterales de la época. Somewhat paradoxically, at the end of the 1930s, the relationship between Mexico and the United States experienced one of its tensest moments, after which it dramatically improved, reaching its zenith in the political and military alliance cemented during World War II. The catalyst for this tension and subsequent reconciliation was, without doubt, the diplomatic conflict that arose after the oil nationalization of 1938. Of the various factors that led to a peaceful negotiated solution to the oil conflict, this article focuses on analyzing two phenomena. Firstly—in order of importance—this article examines the role that the Spanish Civil War played. Although the positions of both governments in relation to the Spanish war were significantly different, the interpretations and lessons concerning potential consequences enabled a greater understanding between the two neighboring countries. Secondly, this article also analyzes the ideological affinities between the New Deal and Cardenismo in the context of the global economic and political crisis of the thirties, seeking to understand their role in facilitating bilateral relations during that period.

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