Mechanical response of two plastic clay soils from Sudan

Vast areas of Sudan and South Sudan are covered by alluvial soils derived from the River Nile and its tributaries, across its historic flood plain. These soils are often highly plastic and expansive in nature and cause many problems in the design, construction and operation of geotechnical structures such as highway foundations and embankments involving compacted fills. The mechanical responses of two natural alluvial (Nile) soils from Khartoum, Sudan, have been investigated experimentally. Disturbed samples of a black cotton clay and red clay, both highly plastic, were used to prepare compacted and reconstituted samples. Undisturbed block samples of the black cotton soil in its unsaturated state were taken to investigate the influence of its natural in-situ fabric. Both soils have been fully characterised and intact, reconstituted, and compacted samples tested using advanced triaxial and oedometer (conventional and osmotic) apparatus. Soil-Water-Retention-Curves (SWRCs) were generated for the soils using the filter paper technique to establish their unsaturated response during drying and wetting cycles (the influence of sample shape was also investigated). The SWRCs indicate that both soils develop significant hysteresis between first drying and wetting curves but for subsequent cycles little hysteresis occurs. The onset and form of cracking was observed during the SWRC drying. There is no significant effect of sample's sizes on SWRC. Both clays exhibit a high swelling potential when the moisture content increases from its in-situ value to full saturation. During undrained shearing reconstituted samples had a much more brittle response after K0 consolidation compared with isotropic consolidation while the soils' stiffness response for both K0 and isotropic consolidation is very similar. The strength of natural unsaturated samples was found to increase with confining stress. Tests using osmotic oedometers indicate that, for both the black and red soils, the magnitude of suction has a significant effect on compression and expansion indices, with them decreasing with increasing suction. The elasto-plastic models proposed by Wheeler and Sivakumar (1995) and Alonso et al. (1990) (BBM) were found to not be suitable for predicting the behaviour of the unsaturated compacted black and red soils as the results show only very limited signs of a `yield point', i.e. there was negligible loading collapse behaviour observed at the stress levels used in the tests performed, for both these Sudanese clays.Open Acces

Leadership Styles and Employee Motivation in Qatar Organizations

Organizations in the public sector in Qatar have a reputation for delivering inefficient services. Leaders lack an understanding of motivational factors affecting public sector employee performance. The purpose of this correlational research was to examine the relationship between leadership styles and employee motivation in public companies in Qatar. The independent variables were the transformational, transactional, and passive-avoidant leadership styles. The dependent variable was employee motivation. The moderator variables were employee age and salary. A sample of 92 employees from 4 public sector organizations in Qatar responded to the online survey. The full range leadership theory served as the theoretical foundation for describing leadership styles of managers as perceived by employees. Self-determination theory served as the theoretical foundation for describing employee motivation. A hierarchical regression model was developed, and results of the study indicated a significant positive correlation between transformational and transactional leadership styles used by managers and employee motivation levels, with a standardized beta coefficient (β) above 0.6, and a significant negative correlation between passive-avoidant leadership style and employee motivation levels, with a standardized beta coefficient (β) below -0.57. Age moderated the relationship between transformational leadership and motivation. Salary moderated the relationship between passive-avoidant leadership and motivation. Leaders of public organizations in Qatar may use the results of this study to better support employee motivation and engagement. The study may contribute to social change by helping managers improve organizational performance and increase efficiency levels

PENGARUH INFRASTRUKTUR DAN ZAKAT TERHADAP PERTUMBUHAN EKONOMI (STUDI KASUS DI KOTA BANDA ACEH)

ABSTRACT This study aims to examine the effect of infrastructure and zakat oneconomic growth in Banda Aceh in 2000-2019. This type of research isdescriptive quantitative and inferential research with the Ordinary Least Square(OLS) method. The data used is secondary data, which consists of data on roadinfrastructure, water, zakat and economic growth. The data is obtained fromBadan Pusat Statistik. Hypothesis testing is used by performing multiple linearregression analysis.The results of this study indicate that water infrastructure,roads and zakat simultaneously have a positive and significant effect on economicgrowth. Then partially shows that water infrastructure has a positive andsignificant effect on economic growth, road infrastructure has a positive andsignificant effect on economic growth and zakat has a positive and significanteffect on a positive and significant effect on economic growth. Therefore, the localauthority in this case is the Banda Aceh City government and Baitul Mal BandaAceh can continue to improve the quality and quantity as well as services in theinfrastructure and zakat sector so that economic growth in Banda Aceh Citygrows well.Keywords: Road Infrastructure, Water Infrastructure, Zakat, Economic Growth ABSTRAK Penelitian ini bertujuan untuk menguji pengaruh infrastruktur dan zakatterhadap pertumbuhan ekonomi di Banda Aceh tahun 2000-2019. Jenis penelitianyang digunakan ialah penelitian deskriptif kuantitatif dan inferensial denganmetode Ordinary Least Square (OLS). Data yang digunakan adalah datasekunder, yang terdiri dari data infrastruktur jalan, air, zakat dan pertumbuhanekonomi. Data tersebut didapatkan dari Badan Pusat Statistik. Pengujian hipotesisdigunakan dengan melakukan analisis regresi linier berganda. Hasil penelitian inimenunjukkan bahwa infrastruktur air, jalan dan zakat secara simultan berpengaruhpositif dan signifikan terhadap pertumbuhan ekonomi. Kemudian secara parsialmenunjukkan bahwa infrastruktur air, berpengaruh positif dan signifikan terhadappertumbuhan ekonomi, infrastruktur jalan berpengaruh positif dan signifikanterhadap pertumbuhan ekonomi serta zakat berpengaruh positif dan signifikanterhadap berpengaruh positif dan signifikan terhadap pertumbuhan ekonomi. Olehkarena itu, otoritas lokal dalam hal ini adalah pemerintah Kota Banda Aceh danBaitul Mal Kota Banda Aceh agar kedepannya dapat terus meningkatkan kualitasdan kuantitas serta pelayanan di bidang infrastruktur dan zakat agar pertumbuhanekonomi di Kota Banda Aceh tumbuh secara baik.Kata kunci: Infrastruktur Jalan, Infrastruktur Air, Zakat, PertumbuhanEkonom

Which Statute Will Trump: The Validity of Class-Action Waivers in Employment Arbitration Agreements

A law can often be a double-edged sword—its mandate or protection of one right will sometimes come at the cost of another. Compounding this problem of unintended consequences is that laws do not operate in a vacuum. Instead, laws interact with other laws, and if they conflict, courts must determine which will prevail. Determining the validity of class-action waivers in employment arbitration agreements will require reconciling the Federal Arbitration Act’s mandate that arbitration agreements be enforced according to their terms against the National Labor Relations Act’s protection of employees’ right to engage in concerted activities for the purpose of mutual aid and protection. The dispute over the validity of these agreements requires courts to determine which law and congressional policy should prevail. The National Labor Relations Board and circuit courts throughout the country have been unable to reach a uniform decision, which has prompted the United States Supreme Court to grant certiorari on a triad of cases concerning this issue. With a decision from the nation’s highest Court expected during the 2017–18 term, this Comment analyzes the background and legal arguments behind these competing statutes to determine how the Court is likely to rule. This Comment concludes that, given the Court’s previous rulings in arbitration and class-action cases and the recent Supreme Court confirmation of Justice Neil Gorsuch, the Court is likely to rule in favor of validating class-action waivers in employment arbitration agreements

Bootstrap Intervals of the Parameters of Lognormal Distribution Using Power Rule Model and Accelerated Life Tests

Assumed that the distribution of the lifetime of any unit follows a lognormal distribution with parameters μ and σ . Also, assume that the relationship between μ and the stress level V is given by the power rule model. Several types of bootstrap intervals of the parameters were studied and their performance was studied using simulations and compared in term of attainment of the nominal confidence level, symmetry of lower and upper error rates and the expected width. Conclusions and recommendations are given

Learning, Scholarship and Public Libraries in Pre and Colonial Sudan

Although the idea of providing public library services to the general public is basically a westernized concept, nevertheless the Sudan has a long tradition of learning and scholarship in which one could argue that an embryonic and rudimentary public library service of some sort had been established. The purpose of this paper is to provide an historical overview of this learning and scholarship development and to explore the forces social, historical and political that led to the emergence of public libraries in pre and colonial Sudan. The historical research method was used to describe such forces employing mainly books, journal articles and to a lesser extent theses and dissertation. This will be followed by a discussion and conclusion

Fired Process Heaters

Non