scholarly journals Wear and Fragmentation Resistance of Mineral Aggregates—A Review of Micro-Deval and Los Angeles Tests

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5456
Author(s):  
Paweł Strzałkowski ◽  
Urszula Kaźmierczak
Keyword(s):  
Los Angeles ◽  
Current Knowledge ◽  
Test Methods ◽  
Research Directions ◽  
Internal Properties ◽  
Steel Balls ◽  
The Impact ◽  
Selection Of ◽  
Mineral Aggregates

The aim of this article is to present the current knowledge and experiences related to wear and fragmentation resistance tests and to indicate those of their aspects that require further research. For this purpose, a review of the literature was performed. Results show that tests of resistance to wear (the MDE/DS test) and fragmentation (the LA test) are performed worldwide according to different standards (and thus following different test methods), which prevents a comparison of the obtained results. Comparative research into the MDE/DS and LA tests indicates that the MDE/DS test is more effective. The disadvantage of both tests lies in the dimension range of the aggregate. In addition, the use of steel balls in the LA test may not reflect the actual influence that the internal properties of the material have on the fragmentation process. A final review of the available knowledge allowed the formulation of proposals regarding further research directions, such as proposed changes of test methods, extensive analysis, and selection of optimal dimensions for tested aggregates, analysis of short-term and long-term tests, as well as extensive research into and an analysis of the impact of crushing on the physical, mechanical, and geometric properties of aggregates.

scholarly journals COVID-19 Infection during Pregnancy: Risk of Vertical Transmission, Fetal, and Neonatal Outcomes

2021 ◽  
Vol 11 (6) ◽  
pp. 483
Author(s):  
Marwa Saadaoui ◽  
Manoj Kumar ◽  
Souhaila Al Khodor
Keyword(s):  
Pregnant Women ◽  
Vertical Transmission ◽  
Current Knowledge ◽  
Limited Data ◽  
Pregnancy Risk ◽  
Public Health Challenge ◽  
Short And Long Term ◽  
Critical Public Health ◽  
The Impact

The COVID-19 pandemic is a worldwide, critical public health challenge and is considered one of the most communicable diseases that the world had faced so far. Response and symptoms associated with COVID-19 vary between the different cases recorded, but it is amply described that symptoms become more aggressive in subjects with a weaker immune system. This includes older subjects, patients with chronic diseases, patients with immunosuppression treatment, and pregnant women. Pregnant women are receiving more attention not only because of their altered physiological and immunological function but also for the potential risk of viral vertical transmission to the fetus or infant. However, very limited data about the impact of maternal infection during pregnancy, such as the possibility of vertical transmission in utero, during birth, or via breastfeeding, is available. Moreover, the impact of infection on the newborn in the short and long term remains poorly understood. Therefore, it is vital to collect and analyze data from pregnant women infected with COVID-19 to understand the viral pathophysiology during pregnancy and its effects on the offspring. In this article, we review the current knowledge about pre-and post-natal COVID-19 infection, and we discuss whether vertical transmission takes place in pregnant women infected with the virus and what are the current recommendations that pregnant women should follow in order to be protected from the virus.

Geochemical Behaviour of Uranium in Sedimentary Formations: Insights From a Natural Analogue Study

2009 ◽  
Author(s):  
Ulrich Noseck ◽  
Vaclava Havlova ◽  
Juhani Suksi ◽  
Thomas Brasser ◽  
Radek Cervinka
Keyword(s):  
Current Knowledge ◽  
Natural Analogue ◽  
Near Surface ◽  
Co2 Partial Pressure ◽  
Long Term Stability ◽  
Reducing Conditions ◽  
Phosphate Mineral ◽  
Sedimentary System ◽  
The Impact

Groundwater data from the natural analogue site Ruprechtov have been evaluated with special emphasis on the uranium behaviour in the so-called uranium-rich clay/lignite horizon. In this horizon in-situ Eh-values in the range of −160 to −280 mV seem to be determined by the SO42−/HS− couple. Under these conditions U(IV) is expected to be the preferential redox state in solution. However, on-site measurements in groundwater from the clay/lignite horizon show only a fraction of about 20% occurring in the reduced state U(IV). Thermodynamic calculations reveal that the high CO2 partial pressure in the clay/lignite horizon can stabilise hexavalent uranium, which explains the occurrence of U(VI). The calculations also indicate that the low uranium concentrations in the range between 0.2 and 2.1μg/l are controlled by amorphous UO2 and/or the U(IV) phosphate mineral ningyoite. This confirms the findings from previous work that the uranium (IV) mineral phases are long-term stable under the reducing conditions in the clay/lignite horizon without any signatures for uranium mobilisation. It supports the current knowledge of the geological development of the site and is also another important indication for the long-term stability of the sedimentary system itself, namely of the reducing geochemical conditions in the near-surface (30m to 60 m deep) clay/lignite horizon. Further work with respect to the impact of changes in redox conditions on the uranium speciation is on the way.

scholarly journals Perspectives on the Capabilities for the Selection of Strategic Projects

2020 ◽  
Vol 12 (19) ◽  
pp. 8191
Author(s):  
Khalifa Mohammed Al-Sobai ◽  
Shaligram Pokharel ◽  
Galal M. Abdella
Keyword(s):  
Large Scale ◽  
Quantitative Methods ◽  
Project Selection ◽  
Economic Benefits ◽  
Research Directions ◽  
Qualitative And Quantitative Methods ◽  
Strategic Project ◽  
Managerial Capabilities ◽  
Selection Of

Strategic projects are large scale, complex, and require significant investments and resources. These projects aim at gaining long-term social and economic benefits. Therefore, organizations focusing on strategic projects should use a consistent approach that suits their strategy, capability, and long-term expectations. Based on the four research questions and content analysis of the literature, generic processes used for the strategic project selection in tandem with the managerial capabilities are identified in this paper. The generic processes and managerial capabilities are used to develop a generic framework for strategic project selection. The framework is used for literature analysis in the paper. The review shows that both qualitative and quantitative methods are used for strategic project selection. Some possible research directions have also been proposed at the end of the review. The paper provides value to both researchers and practitioners in terms of tools available and a guidance on project selection through a structured process framework.

scholarly journals The Impact of Investment Decision and Funding on Financial Performance and Firm Value

2019 ◽  
Vol 8 (2) ◽  
pp. 103
Author(s):  
Hadi Santoso
Keyword(s):  
Data Analysis ◽  
Financial Performance ◽  
Firm Value ◽  
Stock Exchange ◽  
Investment Decision ◽  
Investment Decisions ◽  
The Right ◽  
The Impact ◽  
Selection Of

Managers who are responsible for the management of companies are faced with two important decisions - investment and funding. The right investment decisions and choice of funding sources are important because they affect the company's financial performance. The selection of the types of assets to be invested and the right types of financing sources result in optimal returns for the company. It reflects good company performance and future prospects. In addition, optimal return is a good sign for investors. Companies that perform well experience increase in the value of their firm. This study examined the effect of investment decisions and the selection of appropriate sources of funds on the performance of the company and the consequent impact on the firm value. The study was conducted in two parts. The first part examined the effect of investment decisions on long-term assets with long-term funding on the rate of return and firm value. The second part examined the effect of investment decisions on the company's short-term assets and funding for financial performance and firm value. The case study used in this research is a consumer goods sub-sector company listed on the Indonesia Stock Exchange in the period 2010 to 2017. Path analysis is the data analysis tools that was used. The results of data analysis showed that the asset structure has an effect on financial performance and firm value. The capital structure affects the financial performance but does not affect the firm value of the company. Financial performance was measured by ROI.

scholarly journals Comparing the victimization impact of cybercrime and traditional crime

2021 ◽  
Vol 3 (3) ◽  
pp. 85-110
Author(s):  
Jildau Borwell ◽  
Jurjen Jansen ◽  
Wouter Stol
Keyword(s):  
Law Enforcement ◽  
Literature Review ◽  
Current Knowledge ◽  
Future Research ◽  
Knowledge Gap ◽  
Research Directions ◽  
The Future ◽  
Future Research Directions ◽  
Potential Impact ◽  
The Impact

This paper addresses the importance of building knowledge on the impact of cybercrime victimization. Because the topic is understudied, it is unclear whether the impact of cybercrime differs from that of traditional crime. Our understanding of potential impact differences needs to be improved, considering that society and criminality are digitizing and, consequently, more people are likely to become victims of cybercrime. From a practical perspective, knowledge about the impact of different crimes is important to develop victim policies within law enforcement and other relevant agencies, and to treat victims appropriately. In this paper, a literature review is provided, as well as future research directions to address the current knowledge gap. The future research directions are divided in three topics: (1) distinguishing between cybercrime and traditional crime, (2) classifying cybercrime and traditional crime, and (3) measuring the victimization impact of cybercrime and traditional crime.

scholarly journals Review of Existing Energy Retrofit Decision Tools for Homeowners

2021 ◽  
Vol 13 (18) ◽  
pp. 10189
Author(s):  
Mohammed Seddiki ◽  
Amar Bennadji ◽  
Richard Laing ◽  
David Gray ◽  
Jamal M. Alabid
Keyword(s):  
Financial Support ◽  
Current Knowledge ◽  
Evaluation Criteria ◽  
Data Driven ◽  
Energy Calculation ◽  
Calculation Methods ◽  
Decision Tools ◽  
Energy Retrofit ◽  
The Impact

Energy retrofit tools are considered by many countries as one of the strongest incentives to encourage homeowners to invest in energy renovation. These tools help homeowners to get an initial overview of suitable retrofit measures. Although a large number of energy retrofit tools have been developed to inspire and educate homeowners, energy renovation by individual homeowners is still lagging and the impact of current tools is insufficient as awareness and information issues remain one of main obstacles that hinder the uptake of energy retrofitting schemes. This research extends the current knowledge by analysing the characteristics of 19 tools from 10 different countries. The selected tools were analysed in terms of energy calculation methods, features, generation and range of retrofit measures, evaluation criteria, and indications on financial support. The review indicates that: (1) most toolkits use empirical data-driven methods, pre-simulated databases, and normative calculation methods; (2) few tools generate long-term integrated renovation packages; (3) technological, social, and aesthetic aspects are rarely taken into consideration; (4) the generation of funding options varies between the existing tools; (5) most toolkits do not suggest specific retrofit solutions adapted to traditional buildings; and (6) preferences of homeowners in terms of evaluation criteria are often neglected.

scholarly journals TRANSFORMATION OF ADVERTISING UNDER THE INFLUENCE OF NEW TRENDS OF CONSUMPTION AS A SOCIAL ACTION

2021 ◽  
Author(s):  
Tetiana Reshetilova ◽  
◽  
Tetiana Kuvaieva ◽  
Keyword(s):  
Consumer Behavior ◽  
Social Action ◽  
Social Stratification ◽  
Modern Society ◽  
Modern Information Technology ◽  
Ambiguous Situation ◽  
The Impact ◽  
Selection Of

The article is devoted to the study of advertising transformation under the influence of new trends of consumption as a social action. It is highlighted that the current socio-economic situation is creating new subjects for the analysis of already well-known objects. The place and role of advertising in modern society is certainly based on its market principles in the past, but today it is necessary to take into account a set of influencing factors that were previously mutually exclusive but are now indivisible. The greatest influence is exerted by the socio-cultural aspect of consumer behavior, which is based on values and motivators that come from the lifestyle in a qualitatively new external environment. It means that they are not limited to market transactions. Moreover, in today's conditions, social stratification has receded into the background and is not among the main factors of influence. This transformation of understanding the practice of consumption allows to reasonably recruit and use advertising tools to increase their effectiveness. It is determined that during forming an advertising campaign it is necessary to consider the impact on consumer behavior of modern information technology, namely the selection of the necessary information from the large amount that is available. A large amount of information creates an ambiguous situation for the consumer. This requires the integration of advertising tools. It is established that the parallel use of several advertising media allows to carry out the influence similarly to the technology of purposeful management. The availability of technical means that quickly realize the desire can be recommended for both long-term brand communication and for the short term.

scholarly journals As the Wind Blows: The Effects of Long-Term Exposure to Air Pollution on Mortality

2019 ◽  
Vol 18 (4) ◽  
pp. 1886-1927 ◽  
Author(s):  
Michael L Anderson
Keyword(s):  
Air Pollution ◽  
Los Angeles ◽  
Infant Health ◽  
Short Form ◽  
Adult Mortality ◽  
Significant Loss ◽  
Adult Health ◽  
Life Years ◽  
The Impact

Abstract There is strong evidence that short-run fluctuations in air pollution negatively impact infant health and contemporaneous adult health, but there is less evidence on the causal link between long-term exposure to air pollution and increased adult mortality. This project estimates the impact of long-term exposure to air pollution on mortality by leveraging quasi-random variation in pollution levels generated by wind patterns near major highways. I combine geocoded data on the residence of every decedent in Los Angeles over three years, high-frequency wind data, and Census short form data. Using these data, I estimate the effect of downwind exposure to highway-generated pollutants on the age-specific mortality rate by using orientation to the nearest major highway as an instrument for pollution exposure. I find that doubling the percentage of time spent downwind of a highway increases mortality among individuals 75 or older by 3.8%–6.5%. These estimates are robust and imply significant loss of life years.

Long-Term Survival of Recurrent Intrahepatic Cholangiocarcinoma: The Impact and Selection of Repeat Surgery

2017 ◽  
Vol 42 (6) ◽  
pp. 1848-1856 ◽  
Author(s):  
Tomoaki Yoh ◽  
Etsuro Hatano ◽  
Satoru Seo ◽  
Yukihiro Okuda ◽  
Hiroaki Fuji ◽  
...  
Keyword(s):  
Intrahepatic Cholangiocarcinoma ◽  
Repeat Surgery ◽  
Term Survival ◽  
Long Term Survival ◽  
The Impact ◽  
Selection Of

A Few Aspects on Lubricant Selection for Stepless Chain Coverters: Efficiency and Service Life

1992 ◽  
Author(s):  
G. Schönnenbeck
Keyword(s):  
Friction Coefficient ◽  
Service Life ◽  
Standardized Test ◽  
Test Methods ◽  
Long Term Stability ◽  
Friction Disk ◽  
The Individual ◽  
And Control ◽  
Selection Of

Abstract Stepless vehicle drives will assume their place next to automatic switching units throughout the world if they meet their expected fuel-saving potential. This necessitates optimizing the individual components of the CVT as regards their efficiency. The main source of losses are the hydraulic supply units and the losses which result specifically from non-positive transmission. In the case of stepless chain conveners, these result mainly from friction disk deformation. These losses account for 50 to 70 % of total CVT losses. Both loss components are influenced by the lubricant to a significantly greater extent than it would appear at first sight: In the case of fully-hydraulic clamping and control systems, the viscosity and its long-term stability determines the degree of leakage losses and therefore the size of the pump or pump combinations. This applies to pressure levels between 20 and 40 bar. This in turn is directly proportional to the hydraulic losses on the CVT. The friction coefficient of the lubricant determines the level of the necessary clamping forces. These are responsible for friction-disk deformation. Also of importance as far as the selection of lubricant is concerned is its influence on the CVT service life. The critical service life limits for chain converters are chain breakage (not the subject of this report) and evidence of wear, i.e. grey staining, sheave-grooving, pitting, scoring and rocker pin wear. Standardized test methods exist at P.I.V. for both wear manifestations and for the friction coefficient, these tests allowing a targeted selection of lubricants.

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