scholarly journals Water adsorption and freeze-thaw resistance of limestone treated with Oxal NK100

2019 ◽  
Vol 91 ◽  
pp. 02048
Author(s):  
Elena Korneeva ◽  
Anna Babanina ◽  
Yulia Larionova
Keyword(s):  
Water Absorption ◽  
Air Temperature ◽  
Water Adsorption ◽  
Negative Impact ◽  
External Factors ◽  
Review Of The Literature ◽  
Compound A ◽  
Freeze Thaw ◽  
Before And After

Natural limestone is subjected to negative impact of external factors, such as rain and low air temperature. One of the ways to improve the properties of limestone is considered in the paper, which is its treatment with Oxal NK100 compound. A review of the literature regarding the problem of durability and the use of limestone is presented. The water absorption and freeze-thaw resistance of the rock was determined experimentally before and after processing with a stone reinforcing compound. The analysis of the obtained data is conducted and conclusions about the effectiveness of the Oxal NK100 composition are drawn.

Potential Beneficiation of Readily Available Gold Tailings and Paper Wastes: Development of a New Building Material

2020 ◽  
Vol 46 (3) ◽  
pp. 350-359
Author(s):  
Tebogo Mashifana ◽  
Nastassia Sithole
Keyword(s):  
Water Absorption ◽  
Mine Tailings ◽  
Gold Mining ◽  
Negative Impact ◽  
Daily Basis ◽  
Curing Period ◽  
Before And After ◽  
Gold Mine Tailings ◽  
Gold Tailings ◽  
Land Filling

Gold mine tailings (GMT) generated from gold mining processes are readily available in South Africa. The generated GMT is disposed to the environment by land filling. This occupies considerable land area, which subsequently results into environmental pollution. Numerous industries use paper for a number of applications on daily basis and its generation is inevitable. Unrecycled paper ends up in the landfill, which has a negative impact on the environment, as it is not degradable. This study investigated the blending of GMT and waste paper for the production of building bricks (papercrete). The chemical composition of GMT in terms of elemental, mineralogy and micrograph before and after paper stabilization was examined. Developed composites were cured for 7, 14, 21, 28 days, and the unconfined compressive strength (UCS) and absorption tests were conducted. The results obtained showed an improvement in both the UCS and the water absorption of the bricks with the increment in curing period. The brick cured for 28 days had the highest UCS of 7.76 MPa and the lowest water absorption of 80.43% when compared to the bricks cured for 7,14 and 21 days. The developed papercrete was relatively light in weight; however, they proved not to be suitable for outdoor walls and water logging areas due to their high capability to absorb water.

The dilemmas of the Israeli reality and the choice of war

2019 ◽  
Vol 2 (4) ◽  
pp. 151
Author(s):  
Bashir Hadi Abdul Razak
Keyword(s):  
Negative Impact ◽  
Arab World ◽  
External Factors ◽  
Political Movement ◽  
World Today ◽  
The World ◽  
Arab Israeli Conflict ◽  
Internal And External Factors

The Arab-Israeli conflict is among the longest and most complex conflicts in the world today, a conflict that transcends borders or a difference of influence. It is a struggle for existence in every sense. Since the establishment of Israel in 1948, one of the regional forces whose political movement is determined by the Arab world has become the result of the internal and external factors and changes that affect it. This entity is hostile to the Arabs, Which would have a negative impact on the regional strategic situation.

Migration Patterns and Labor Market Outcomes

2018 ◽  
Author(s):  
Anda David ◽  
Mohamed Ali Marouani
Keyword(s):  
Labor Market ◽  
Negative Impact ◽  
Labor Market Outcomes ◽  
Wealth Index ◽  
Transition Matrices ◽  
Market Outcomes ◽  
Migration Patterns ◽  
Depth Analysis ◽  
Before And After ◽  
Spatial Composition

This chapter focuses on the external effects of emigration on non-migrants, and particularly on the interactions with labor market outcomes in Tunisia before and after the revolution. Using the new Tunisia Labor Market Panel Survey (TLMPS), we conduct an in-depth analysis of the structure and dynamics of migration, including the profile of migrants and their origin households, mainly in terms of skills and spatial composition. We investigate transition matrices, employment status, income for current migrants and returnees, and the evolution of remittances. Our analysis confirms the role of emigration as a safety valve for the Tunisian labor market. Moreover, origin households of migrants have a significantly higher wealth index. Our analysis also tends to confirm the effects of remittances on labor supply of non-migrants, which can have a negative impact on Tunisia’s unemployment rate when a crisis in destination countries affects the remittance rate negatively.

Impact of Dividend Tax Change on the Payout Policy of Indian Companies

2019 ◽  
Vol 20 (5) ◽  
pp. 1282-1291
Author(s):  
Sanjay Dhamija ◽  
Ravinder Kumar Arora
Keyword(s):  
Negative Impact ◽  
Payout Policy ◽  
Tax Law ◽  
Dividend Payout ◽  
Inside Ownership ◽  
Regulatory Changes ◽  
Before And After ◽  
The Government ◽  
The Impact ◽  
Dividend Tax

The article examines the impact of regulatory changes in the tax on dividends on the payout policy of Indian companies. The tax law was recently amended to levy tax on dividends received by large shareholders. As the promoters group is the largest shareholder, this is expected to have a negative impact on the payout policy of companies. Furthermore, companies with larger promoter holdings have a higher motivation to reduce their payout. The study covers 370 companies present in the BSE 500 Index and compares the dividend payout of the companies before and after the introduction of tax levy. The study finds that the newly introduced tax indeed caused a shift in the dividend policy of companies, particularly those companies which have high levels of inside ownership. The findings have significant implications for companies, investors and the government.

Spouse Caregivers' Perceptions of Influence of Dementia on Marriage

2002 ◽  
Vol 14 (1) ◽  
pp. 47-58 ◽  
Author(s):  
Ulla Eloniemi-Sulkava ◽  
Irma-Leena Notkola ◽  
Kaija Hämäläinen ◽  
Terhi Rahkonen ◽  
Petteri Viramo ◽  
...  
Keyword(s):  
Behavioral Change ◽  
Intervention Study ◽  
Negative Impact ◽  
Behavioral Changes ◽  
Telephone Interviews ◽  
Before And After ◽  
Spouse Caregivers ◽  
Dementing Illness ◽  
Male Patients ◽  
Patients Experience

Objectives: To investigate what kind of changes spouse caregivers of demented patients experience after the onset of dementia (a) in the general atmosphere, happiness, and relations of marriage and (b) in the sexual side of marriage. Design: Semistructured telephone interviews of spouse caregivers of demented patients. Setting: Community-living demented patients and their spouse caregivers in eastern Finland. Participants: The spouse caregivers of 42 demented patients recruited from a previous intervention study. Measures: The questionnaire covered different areas of marriage from the time before and after the onset of dementia. Results: A statistically significant decline had occured in extent of happiness (p = .012), in equal relations (p = .001), and in patients' expressions of sexual needs (p < .001) when compared the time before and after dementia. Twenty-five (60%) of the caregivers reported that the demented patient had shown at least one negative sexual behavioral change during the course of dementia. Seven male patients (24%) had shown the behavioral symptom of constantly expressing need for making love. One in 10 caregivers had experienced positive sexual behavioral changes. In one third of the patients, the expressions of tenderness towards the caregiver had increased. Dementia did not affect significantly the general atmosphere of the marriage. Out of those still in home care, at 3 years from the onset of dementia, 19 couples (46%) continued to practice intercourse, at 5 years the number was 15 couples (41%), and at 7 years it had declined to 7 couples (28%). Conclusions: Dementing illness has a major negative impact on many dimensions of marriage. However, there are also positive changes and preserved aspects of marriage. Dementia seems to have a surprisingly little impact on whether the couple continues to have intercourse when compared with the general aging population.

scholarly journals Phantom Eye Syndrome: A Review of the Literature

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Agda M. Andreotti ◽  
Marcelo C. Goiato ◽  
Eduardo P. Pellizzer ◽  
Aldiéris A. Pesqueira ◽  
Aimée M. Guiotti ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Drug Therapy ◽  
Phantom Pain ◽  
Direct Influence ◽  
Psychological Approach ◽  
Review Of The Literature ◽  
Eye Trauma ◽  
Pubmed Database ◽  
Before And After

The purpose of this literature review was to describe the main features of phantom eye syndrome in relation to their possible causes, symptoms, treatments, and influence of eye amputation on quality of life of anophthalmic patients. For this, a bibliographical research was performed in Pubmed database using the following terms: “eye amputation,” “eye trauma,” “phantom eye syndrome,” “phantom pain,” and “quality of life,” associated or not. Thirteen studies were selected, besides some relevant references contained in the selected manuscripts and other studies hallowed in the literature. Thus, 56 articles were included in this review. The phantom eye syndrome is defined as any sensation reported by the patient with anophthalmia, originated anophthalmic cavity. In phantom eye syndrome, at least one of these three symptoms has to be present: phantom vision, phantom pain, and phantom sensations. This syndrome has a direct influence on the quality of life of the patients, and psychological support is recommended before and after the amputation of the eyeball as well as aid in the treatment of the syndrome. Therefore, it is suggested that, for more effective treatment of phantom eye syndrome, drug therapy should be associated with psychological approach.

scholarly journals Effects of Anti-Graffiti Protection on Concrete Durability

2014 ◽  
Vol 634 ◽  
pp. 517-526 ◽  
Author(s):  
Elsa Neto ◽  
Ana Souto ◽  
Aires Camões ◽  
Arlindo Begonha ◽  
Paulo Cachim
Keyword(s):  
Water Absorption ◽  
Atmospheric Pressure ◽  
Surface Characteristics ◽  
Concrete Surface ◽  
Experimental Program ◽  
Concrete Durability ◽  
Protection Systems ◽  
Before And After ◽  
Paint Removal ◽  
Durability Of Concrete

The heritage of fair-faced concrete, largely built in the twentieth century and nowadays recognized as heritage to be protected, is susceptible to attacks by graffiti, a form of vandalism that causes a major social and economic impact on society. Concrete is a porous material sometimes deteriorated over the years, and the interactions between the inks and the substrate and removal methods sometimes deteriorate or alter the concrete surface, especially if it is necessary to repeat the removal process. The anti-graffiti products are applied on the surface of the concrete, hindering the adhesion of paints or preventing its penetration into the pores of concrete, which in turn facilitates their removal. However, it appears that many of the existing protective products on the market may also alter the surface characteristics of the concrete irreversibly. Considering that the durability of concrete depends on the composition and characteristics of the surface, it is essential to know the effects of anti-graffiti protection systems on the durability of concrete and adopt the appropriate methodology to preserve this heritage. Thus, an experimental program was developed for analyzing changes in durability indicators and surface properties that protect concrete from deterioration (i) concrete without protection before and after application of spray paint, (ii) concrete with protection before and after application of spray paint and (iii) after paint removal were studied. Two anti-graffiti products were evaluated: a permanent and a sacrificial one. Effects of the anti-graffiti systems on the concrete durability are investigated and the tests performed include: water absorption by capillary and immersion at atmospheric pressure. The results of the water absorption tests show that the graffiti protection reduces the water absorption into the concrete and facilitates the removal of the graffiti without affecting negatively the characteristics of the surface and thus contributing to improve its durability.

scholarly journals Effects of Imposed Damage on the Capillary Water Absorption of Recycled Aggregate Concrete

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Qi Gao ◽  
Zhiming Ma ◽  
Jianzhuang Xiao ◽  
Fuan Li
Keyword(s):  
Absorption Coefficient ◽  
Water Absorption ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Capillary Absorption ◽  
Capillary Water ◽  
Aggregate Concrete ◽  
Capillary Water Absorption ◽  
Freeze Thaw ◽  
Loading Level

Capillary water absorption of concrete is closely related to its pore structure, permeability, and durability. This paper intensively investigates the effects of imposed damage, including freeze-thaw damage and loading damage, on the capillary water absorption of recycled aggregate concrete (RAC). Freeze-thaw cycle test, loading test, and the experiment of capillary water absorption were carried out, respectively. The results demonstrate that the addition of recycled coarse aggregate (RCA) results in the increase in the capillary absorption behavior of RAC without imposed damage, and there exists a linear correlation between the behaviors of capillary water absorption and chloride penetration of RAC. The imposed freeze-thaw damage or load damage of RAC boosts with the increase of RCA replacement percentages after suffering the same freeze-thaw cycles or loading level. The imposed freeze-thaw damage and load damage further lead to the increase in the capillary water absorption of RAC, and the capillary absorption coefficient of RAC increases linearly with the increased RCA replacement percentages, after suffering the same freeze-thaw cycles or loading level. Furthermore, capillary absorption coefficient increases linearly with the growth of imposed freeze-thaw damage or load damage degree, which can be used to estimate the capillary absorption behavior of RAC exposed to the extreme environment.

Modelling pavement temperature for winter maintenance operations

2004 ◽  
Vol 31 (2) ◽  
pp. 369-378 ◽  
Author(s):  
Aly Sherif ◽  
Yasser Hassan
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
Negative Impact ◽  
Weather Conditions ◽  
Statistical Modelling ◽  
Dew Point ◽  
Road Maintenance ◽  
Winter Maintenance ◽  
Pavement Surface ◽  
Pavement Temperature

Road and highway maintenance is vital for the safety of citizens and for enabling emergency and security services to perform their essential functions. Accumulation of snow and (or) ice on the pavement surface during the wintertime substantially increases the risk of road crashes and can have negative impact on the economy of the region. Recently, road maintenance engineers have used pavement surface temperature as a guide to the application of deicers. Stations for road weather information systems (RWIS) have been installed across Europe and North America to collect data that can be used to predict weather conditions such as air temperature. Modelling pavement surface temperature as a function of such weather conditions (air temperature, dew point, relative humidity, and wind speed) can provide an additional component that is essential for winter maintenance operations. This paper uses data collected by RWIS stations at the City of Ottawa to device a procedure that maximizes the use of a data batch containing complete, partially complete, and unusable data and to study the relationship between the pavement surface temperature and weather variables. Statistical models were developed, where stepwise regression was first applied to eliminate those variables whose estimated coefficients are not statistically significant. The remaining variables were further examined according to their contribution to the criterion of best fit and their physical relationships to each other to eliminate multicollinearities. The models were further corrected for the autocorrelation in their error structures. The final version of the developed models may then be used as a part of the decision-making process for winter maintenance operations.Key words: winter maintenance, pavement temperature, statistical modelling, RWIS.

scholarly journals Impact of freeze-thaw cytoablation on aqueous outflow patterns in ex vivo anterior chamber perfusion cultures and whole eyes

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 525
Author(s):  
Raoul Verma-Fuehring ◽  
Mohamad Dakroub ◽  
Alicja Strzalkowska ◽  
Piotr Strzalkowski ◽  
Hong Han ◽  
...  
Keyword(s):  
Trabecular Meshwork ◽  
Structural Changes ◽  
Ex Vivo ◽  
Anterior Segment ◽  
Large Change ◽  
Invasive Technique ◽  
Freeze Thaw ◽  
Before And After ◽  
Human Eyes ◽  
Porcine Eyes

Background: Porcine eyes have been widely used as ex vivo models in glaucoma research, as they share similar features with human eyes. Freeze-thawing is a non-invasive technique that has been used to obliterate living cells in anterior segment ex vivo cultures, to prepare them for further research such as cellular repopulation. This technique has previously been shown to reduce the intraocular pressure (IOP) in porcine eyes. The aim of this study was to investigate whether freeze-thaw cytoablation causes corresponding canalogram outflow changes in perfused anterior segment cultures (AFT) and whole porcine eyes (WFT). We hypothesized that the known IOP drop in AFT after trabecular meshwork ablation by freeze-thaw would be accompanied by a similarly large change in the distal outflow pattern. Methods: Two-dye (fluorescein and Texas red) reperfusion canalograms were used to compare the outflow time before and after two -80°C cycles of freeze-thaw. We assigned 28 freshly enucleated porcine eyes to four groups: perfused anterior segment dye controls (ACO, n = 6), perfused whole eye dye controls (WCO, n = 6), freeze-thaw treated anterior segment cultures (AFT, n = 10), and freeze-thaw treated whole eyes (WFT, n = 6). Results: In control groups ACO and WCO, the two different dyes had similar filling times. In AFT, the outflow pattern and filling times were unchanged. In WFT, the temporal superior quadrant filled more slowly (p = 0.042) while all others remained unchanged. The qualitative appearance of distal outflow spaces was altered only in some eyes. Conclusions: Freeze-thaw cytoablation caused neither loss nor leakage of distal outflow structures. Surprisingly, the loss of an intact trabecular meshwork over the entire circumference did not result in a general acceleration of quadrant outflow times. The results validate freeze-thawing as a method to generate an extracellular matrix without major structural changes.

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