scholarly journals Development of flume model of inclined capillary barrier (clay silt/CDW) in a subtropical climate scenario

2021 ◽  
Vol 337 ◽  
pp. 04007
Author(s):  
Thays C.F. Oliveira ◽  
Bianca G.S. Dezen ◽  
Julio C. Bizarreta-Ortega
Keyword(s):  
Clay Soil ◽  
Climate Scenario ◽  
Heavy Rain ◽  
Subtropical Climate ◽  
Capillary Barrier ◽  
Urban Centers ◽  
Capillary Barriers ◽  
Construction And Demolition Wastes ◽  
The One ◽  
Interest In Research

Interest in research on capillary barrier (CB) in regions with humid climates (tropical and subtropical) is increasing. One of the main advantages of such cover type is the greater flexibility regarding the materials that could compose it. A possibility is the use of construction and demolition wastes (CDW), which would contribute to the solution of CDW destination, a problem in urban centers. Thus, the present work aimed an experimental evaluation of CB cover with CDW in its composition. A CB cover system was reproduced in a physical model in acrylic box, with clay soil as capillary layer and CDW as capillary block, given its granulometric and hydraulic contrast. The layers were arranged with the usual landfill slope, of 1:3, and a very heavy rain, of 90 mm, was simulated. Three tests were performed on the flume model, in which initial CDW saturation degree (S0) was varied in 4,5%, 10,3% and 17,3%. Results indicate formation, indeed, of capillary barrier between the two used materials. The most efficient model was the one with lowest initial CDW S0, of 4,5%. As the CWD S0 increased, time of flow permanence at materials interface decreased, indicating a CWD S0 in which such capillary barriers no longer function effectively. Regarding percolation rate, the maximum for a 90 mm rainfall was 2,7%, which fits the landfill cover projects criteria consulted.

The Contributions of Oscar Halecki to American Historical Scholarship

1976 ◽  
Vol 4 (2) ◽  
pp. 89-97
Author(s):  
Thaddeus V. Gromada
Keyword(s):  
World War Ii ◽  
Civil Rights ◽  
New England ◽  
The United States ◽  
Urban Centers ◽  
Oil Refineries ◽  
Middle Atlantic ◽  
Steel Mills ◽  
Social Opportunities ◽  
The One

Most of the one and one-half million Poles who immigrated to the United States before World War II were people of rural, Catholic, Slavic stock in search of greater economic and social opportunities. They settled in urban centers primarily in the middle Atlantic, mid-Western, and New England states where they formed communities (Polonias) around the steel mills, coal and iron mines, slaughter houses and meat packing plants, oil refineries, shoe and textile factories, granaries and milling plants. Their labor was an important element in the industrialization of America. They were among the millions of unknown persons from eastern and southern Europe, as Michael Novak put it, “who have strengthened family and neighborhood life in America, and from 1930's to the present have made possible the longest strides in the nation's history in economic matters and civil rights.” Very few scholars and intellectuals, however, could be found among these Polish immigrants. When Polish scholars, intellectuals, or artists emigrated from partitioned Poland, usually after unsuccessful revolutions, they settled in France or some other European country.

scholarly journals Congenital goitre in sheep in southern Tasmania

1975 ◽  
Vol 26 (4) ◽  
pp. 751 ◽  
Author(s):  
M Statham ◽  
AC Bray
Keyword(s):  
Drinking Water ◽  
Soil Type ◽  
Clay Soil ◽  
Subterranean Clover ◽  
Moisture Stress ◽  
Iodine Intake ◽  
Minimum Level ◽  
Soil Ingestion ◽  
The One ◽  
Animal House

Congenital goitre was first recorded in Tasmanian sheep In 1945. Severe but sporadic outbreaks have since occurred in 1956, 1964 and 1968. The disease seemed to be associated with particular farms and its incidence often differed markedly between ewe flocks on the one farm. A survey indicated that the condition was mainly confined to the Derwent Valley and the northern Midlands. Studies involved a grazing trial near Bothwell, where goitre was endemic, and included supporting animal house tnals and plant growth studies. Soil type was shown to be a major factor in the disease: ewes grazing pasture on a sandy soil produced many more goitrous lambs than ewes grazing pasture on clay soil. Analyses of the two pastures revealed that those on sandy so11 contained less iodine than those on clay soil but neither contained the minimum level necessary to prevent goitre. Observations revealed that outbreaks of the disease followed wet autumns with subsequent lush pasture during pregnancy. This correlation could be explained if pasture grown under moist conditions contained less iodine than pasture grown under moisture stress. However, experiments with the two main pasture species (perennial ryegrass and subterranean clover) showed that plant iodine levels were not affected by the water supply. Two goitrogenic agents, nitrate and thiocyanate, were present in the pastures, but they were not considered to be Important in the aetiology of the disease. Similarly, the drinking water was found to be unimportant, even though the two sources available contained widely different amounts of iodine. Apparently, between-year variation in the incidence of goitre and the effect of soil type can best be explained by a varying iodine intake dependent on soil ingestion which varies with pasture availability. This hypothesis is discussed in the light of the results.

Geotextiles to Mitigate Frost Effects in Soils: A Critical Review

1996 ◽  
Vol 1534 (1) ◽  
pp. 5-11
Author(s):  
Karen S. Henry
Keyword(s):  
Field Trials ◽  
Frost Heave ◽  
Laboratory Research ◽  
Capillary Barrier ◽  
Subgrade Soil ◽  
Capillary Barriers ◽  
Geotechnical Structures ◽  
Barrier Performance ◽  
Base Course ◽  
Selection Of

The use of geotextiles to mitigate frost effects in soils has been studied, but few techniques have been developed. Guidelines developed for the placement of granular capillary barriers are presented to serve as preliminary guidelines for geotextile capillary barriers. Laboratory research shows that pore size distribution, wettability, and, for some geotextiles, thickness influence capillary barrier performance in a given soil. Geotextiles that easily wet do not reduce frost heave and may even exacerbate it. On the basis of the literature reviewed, guidance for selection of geotextile capillary barriers in field trials is given. If geotextiles function as capillary barriers during freezing and reinforce or separate and filter the subgrade at the base course interface during thaw, then the potential exists for their use in a combination of functions to reduce frost-related damage in geotechnical structures. It was found that properly designed geotextiles have the potential to reduce frost heave by functioning as capillary barriers, they can be filters for capillary barriers, and they can provide reinforcement or separation or filtration (or all of these) of the subgrade soil to reduce thaw-related damage.

scholarly journals The Use of Laser Precipitation Monitor (LPM) of Disdrometer and Weather Radar to Determine the Microphysics Characteristics of Extreme Rainfall in Jakarta. (Jakarta Flood Case Study February 25, 2020)

2021 ◽  
Vol 893 (1) ◽  
pp. 012017
Author(s):  
I D G A Putra ◽  
A Sopaheluwakan ◽  
B P Adi ◽  
K A Sudama ◽  
J Rizal ◽  
...  
Keyword(s):  
Extreme Rainfall ◽  
Weather Radar ◽  
Heavy Rain ◽  
Maximum Diameter ◽  
Convective Clouds ◽  
Data Volume ◽  
Accumulated Rainfall ◽  
The One ◽  
The Relationship

Abstract Heavy rains on February 24, 2020, caused flooding in most parts of Jakarta and its surroundings. The one-day observation of accumulated rainfall from the Laser Precipitation Monitor (LPM) was recorded at 358.6 mm/day at the Kemayoran station on February 25, 2020, at 00.00 UTC (07.00 Jakarta Time). In this study, analysis of the microphysical characteristics of extreme rainfall using LPM installed at Kemayoran meteorology station and weather radar at Cengkareng meteorology station with a spatial radius of 250 km. LPM is used to measure the diameter of the raindrops, the velocity of falling raindrops, LPM reflectivity, and the amount of accumulated rainfall with time resolution per minute and stored in excel data format. While the weather radar is used to measure the reflectivity spatially and temporally in the data volume format (.vol). The method used is, first, to find the relationship between LPM reflectivity and the amount of LPM rainfall with regression analysis. Second, the radar reflectivity is converted into estimated rainfall intensity for the Jakarta area and its surroundings. The results of this study found a relationship between LPM reflectivity (X) and rainfall accumulation LPM (Y) to form a regression relationship with the formula Y = 0.013X with R2 = 0.3777. Based on the record of the LPM time series, the peak of rainfall occurred at 18.17 UTC with 1000 raindrops, the maximum fall speed was 10 m/s, and the maximum diameter is 8.5 millimeters. Based on the results of microphysical measurements of LPM, spatial plots, and vertical cross-section radar, it can be concluded that flooding in Jakarta is due to heavy rain from convective clouds.

scholarly journals The role and development perspectives of small towns in central Serbia

Spatium ◽  
2006 ◽  
pp. 8-15 ◽  
Author(s):  
Nenad Spasic ◽  
Jasna Petric
Keyword(s):  
Rural Areas ◽  
Small Towns ◽  
Urban Centers ◽  
Social Exchanges ◽  
Large Cities ◽  
Rural And Urban ◽  
Urban Classification ◽  
Spatial Changes ◽  
Real Risk ◽  
The One

The link between urban centers and the countryside, including movement of people, goods, capital and other social exchanges, play an important role in processes of rural and urban change of a country. Major demographic and spatial changes have been typical for Serbia in the second half of the 20th century, caused by a dynamic primary urbanization process, i.e. by intense migration trends between rural areas and towns (cities). A special attention in this paper is given to the small urban centers in Serbia (small towns with population of less than 20,000) as the first magnet in proximate contact with the rural surroundings, and the one that therefore could have the greatest influence on organization structure and development prospects of the rural areas. In addition to being difficult to substantiate criteria for urban classification, small towns themselves do not represent a homogeneous group of settlements, and this makes it even harder to put up generalizations that would fit to all the settlements of this kind either within our country or cross-borders. However, here are identified certain common features for the small towns in Central Serbia and their development perspective is analyzed in relation to medium towns and cities of the same territory in consideration. Finally, this paper discusses the importance of policies for small town development in light of a real risk that the process of globalisation may lead to the justification of a new concentration of activities in the large cities, increasing the already significant regional differences in living conditions and economic development.

Town and Steppe in Ottoman Syria: Hostility, Exploitation and Cooperation in the Late Seventeenth and Eighteenth Centuries

Der Islam ◽  
2015 ◽  
Vol 92 (1) ◽  
Author(s):  
James A. Reilly
Keyword(s):  
Nineteenth Century ◽  
Eighteenth Century ◽  
Urban Life ◽  
The Other ◽  
Urban Centers ◽  
Other Hand ◽  
Literary Sources ◽  
The One ◽  
Urban People ◽  
Different Sources

AbstractLate-seventeenth- and eighteenth-century sources from the Homs and Hama region in Ottoman Syria present contrasting portrayals of Bedouins. Taken together, these sources offer conflicting perspectives with respect to relationships between peoples of the towns and the steppe. On the one hand, literary sources typically portray Bedouins as antitheses of urban life, as savage wanderers who lived outside the norms of propriety and who collectively posed a threat to the wellbeing and property of settled people and of travelers. But on the other hand, legal sources portray Bedouins variously as targets of exploitation or taxation by urban-based governments; or as partners with urban people in contractual undertakings; or as imperial subjects who, like any others, would seek justice in the urban Sharīʿa courts. The article explores these differing characterizations, and seeks to explain the multifarious realities that different sources convey. It concludes by suggesting that relationships between town and steppe were on their way to becoming more institutionalized in the last years of the eighteenth century. This development foreshadowed documented nineteenth-century trends in which urban civil norms and institutions became noticeable in the lives of Bedouins who lived in proximity to towns and urban centers.

Isotopic studies of the nitrogen balance in a cracking clay. II. Recovery of nitrate 15N added to columns of packed soil and microplots growing wheat in the field

Soil Research ◽  
1975 ◽  
Vol 13 (1) ◽  
pp. 53 ◽  
Author(s):  
ET Craswell ◽  
AE Martin
Keyword(s):  
Nitrogen Balance ◽  
Clay Soil ◽  
Heavy Rain ◽  
Plant Analysis ◽  
The Third ◽  
Isotopic Studies ◽  
Heavy Clay ◽  
Nitrate Fertilizer ◽  
Series Of Experiments

In a series of experiments, 15N-labelled nitrate fertilizer was used to study the nitrogen balance of a heavy clay soil. Two of the experiments employed 60-cm deep, 16-cm diameter columns of packed soil. In the first, no added 15N was lost until heavy rain saturated the soil in the undrained columns. Subsequently, fallow and planted columns lost 25% of the 15N added. While denitrification appeared primarily responsible for these losses, some of the 15N may have been lost by weathering of the plants during senescence. This experiment was repeated with precautions to prevent excessive rain saturating the soil. After 16 weeks, only 6 � 4.5% of the added 15N was not accounted for by soil and plant analysis. In the third experiment, I5N was added to 16-cm diameter confined microplots in situ. The microplots were fallow and were confined by 60-cm deep plastic pipe. After 16 weeks, during which 190 mm of rain fell, 97.7 � 2.4% of the added 15N was recovered.

scholarly journals Observations of capillary barriers and preferential flow in layered snow during cold laboratory experiments

2016 ◽  
Vol 10 (5) ◽  
pp. 2013-2026 ◽  
Author(s):  
Francesco Avanzi ◽  
Hiroyuki Hirashima ◽  
Satoru Yamaguchi ◽  
Takafumi Katsushima ◽  
Carlo De Michele
Keyword(s):  
Grain Size ◽  
Spatial Variability ◽  
Liquid Water ◽  
Laboratory Experiments ◽  
Preferential Flow ◽  
Liquid Water Content ◽  
Water Infiltration ◽  
Richards Equation ◽  
Capillary Barrier ◽  
Capillary Barriers

Abstract. Data of liquid water flow around a capillary barrier in snow are still limited. To gain insight into this process, we carried out observations of dyed water infiltration in layered snow at 0 °C during cold laboratory experiments. We considered three different finer-over-coarser textures and three different water input rates. By means of visual inspection, horizontal sectioning, and measurements of liquid water content (LWC), capillary barriers and associated preferential flow were characterized. The flow dynamics of each sample were also simulated solving the Richards equation within the 1-D multi-layer physically based snow cover model SNOWPACK. Results revealed that capillary barriers and preferential flow are relevant processes ruling the speed of water infiltration in stratified snow. Both are marked by a high degree of spatial variability at centimeter scale and complex 3-D patterns. During unsteady percolation of water, observed peaks in bulk volumetric LWC at the interface reached  ∼ 33–36 vol % when the upper layer was composed by fine snow (grain size smaller than 0.5 mm). However, LWC might locally be greater due to the observed heterogeneity in the process. Spatial variability in water transmission increases with grain size, whereas we did not observe a systematic dependency on water input rate for samples containing fine snow. The comparison between observed and simulated LWC profiles revealed that the implementation of the Richards equation reproduces the existence of a capillary barrier for all observed cases and yields a good agreement with observed peaks in LWC at the interface between layers.

scholarly journals Migration and its Impact on Political Scenario:The Case of Karachi

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Mehtab S. Karim , Dr. Huma Baqai
Keyword(s):  
Urban Areas ◽  
State Level ◽  
High Fertility ◽  
Urban Centers ◽  
Political Consequences ◽  
Fault Lines ◽  
The Government ◽  
Increasing Demand ◽  
The One ◽  
The Impact

The impact of population growth is felt on every wake of life. Themovement of population from one country to another or within a countryhas its own consequences. Goldstone et al (2012) have thus argued, thatthe world’s population is changing in ways that are historicallyunprecedented, having its own political consequences such as, theperformance of the government due to increasing demand for services andthe distribution of political power at intra-state level. Thus, internalmigration, which is from high fertility rural zones to urban centers -indeveloping countries like Pakistan- in search of livelihood andemployment, results in concentration of population in slums and squattersettlements on the one hand and a youth bulge in urban areas, furthercontributing to this phenomenon and unprecedented urbanization. State’sinability to address this demographic change effectively results in strainsresources and poor governance. In turn, it creates xenophobia, wherenative populations blame the new migrants for deteriorating civicamenities; and generates various conflicts of critical nature. Pakistan,since its inception as an independent country, has experienced bothinternational and internal migration that resulted in socio-economiccrisis, political agitation and violent ethnic conflicts. In this backdrop, this paper takes into account the migration patterns in Pakistan since 1947 and focuses on Karachi for it being the most affected city. It theorizes that the conflict matrix of Karachi is fairly indicative of fault lines and argues that these fault lines will turn into gaping holes if timely actions are not taken.  

scholarly journals FORMATION OF URBAN PUBLIC SPACES IN THE ARCHITECTURE OF POSTMODERNISM

2021 ◽  
pp. 89-97
Author(s):  
Olena Oliynyk
Keyword(s):  
Urban Space ◽  
Urban Landscape ◽  
Historical Memory ◽  
Urban Structure ◽  
City Image ◽  
Architectural Style ◽  
Urban Centers ◽  
Architectural Elements ◽  
Characteristic Features ◽  
The One

The article deals with the most characteristic features of postmodernism in architecture and in the formation of urban spaces. Postmodernism in architecture was involved as a solution that would combine the rationality and feasibility of modernism with artistic and design solutions. However, in the postmodern era, the urban environment is gradually losing its historical memory, its importance as an anthropological category and as a place of identity identification. Urban centers are turning into purely commercial theme parks for tourists. Postmodern space is an urban structure formed by signs that meet the demands of society. The Postmodern City Image is a conglomerate of ideas and images built with the help of visual personality memory. Rem Koolhaas calls this phenomenon a «Junkspace»,  built as a conglomeration of ideas, concepts and dreams. This space is designed to please people thanks to whimsical and exaggerated elements: neon, casinos and buildings that combine architectural elements of any age with the intention to create a new architectural style. Las Vegas is a hypertrophied example of a postmodern city. Its urban landscape leaves facades and walls aside, replacing them with signs and symbols. Such a symbolic place becomes timeless, unrealistic and transit, not intended for everyday life. Space and time in such a city lose their essence. Urban space brings together different elements from other historical, artistic and cultural eras to interpret them as reflecting modernity. The value of images copied from historical reality becomes more important than reality itself. Humanity regards this unreal world as an idealized model of society, parallel to the one that actually exists, more attractive and interesting. Thus, the very essence of the architecture, the meaning of which is replaced by temporary advertising symbols, is lost.

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