Bed-load transport for steady flows and unsteady oscillatory flows

An experimental study was focused on the process of sediment transport in unsteady flow conditions due to wave action. Wave-induced oscillatory flow conditions near the seabed were simulated at full scale (1:1) in a new large oscillating water tunnel. Two sets of experiments (series A and B) were carried out. During series A, bed forms and wave-cycle averaged suspended sediment concentrations were measured under sinusoidal waves. Series B focused on measurement of the wave-cycle averaged sediment transport rates under regular and random asymmetric oscillatory flows (upper shoreface conditions) and was aimed at the verification of quasi-steady formulas for the description of cross-shore sediment transport.

Bedform dimensions appeared to decrease considerably under the influence of wave asymmetry and wave randomness. Only the measured ripple dimensions under asymmetric waves (series B) showed good agreement with Nielsen's (1979) relations. For most of the series B experiments the bed was plane (sheet flow), the net sediment transport was directed “onshore” and the measured transport rates showed a strong correlation with the velocity moment . An empirical quasi-steady transport model is proposed which is based on the new tunnel data and other existing data sets. The limitations of the quasi-steady model approach became clear in the rippled-bed regime and through the presence of a consistent influence of the wave period in plane-bed conditions. In rippled-bed conditions the suspended concentration profiles followed a negative exponential distribution. For most of the experiments the measured concentration decay length showed a linear relation with the ripple height. In plane-bed/sheet flow conditions the measured suspended concentration profiles followed a negative power function. The power or concentration decay parameter was constant (α ≃ 2.1) for a wide range of velocity conditions. It is suggested that the mobile bed (sheet flow layer) has a strong damping effect on the mixing of suspended sediments (turbulence damping).

Sediment transport in oscillatory boundary layers in cases of rippled beds and sheet flow

Sheet flow and suspension of sand in oscillatory boundary layers

A model is presented for concentrated sediment transport that is driven by strong, fully developed turbulent shear flows over a mobile bed. Balance equations for the average mass, momentum and energy for the two phases are phrased in terms of concentration–weighted (Favre averaged) velocities. Closures for the correlations between fluctuations in concentration and particle velocities are based on those for collisional grain flow. This is appropriate for particles that are so massive that their fall velocity exceeds the friction velocity of the turbulent fluid flow. Particular attention is given to the slow flow in the region of high concentration above the stationary bed. A failure criterion is introduced to determine the location of the stationary bed. The proposed model is solved numerically with a finite–difference algorithm in both steady and unsteady conditions. The predictions of sediment concentration and velocity are tested against experimental measurements that involve massive particles. The model is further employed to study several global features of sheet flow such as the total sediment transport rate in steady and unsteady conditions.

On two-phase sediment transport: sheet flow of massive particles

Twenty-five years with OBS sensors: The good, the bad, and the ugly

Sediment transport in oscillatory boundary layers under sheet-flow conditions

Purpose




This study aims to examine perceptions in Kuwait about women’s leadership in management.




Design/methodology/approach




This study includes a review of data on the gender gap across Middle East/North Africa (MENA) countries, comparison with selected Asian and Western countries and summaries of multiple small surveys in Kuwait on women in management. The surveys were all convenience samples ranging from 100-500, targeting middle-class respondents.




Findings




The MENA is behind most of the world in closing the gender gap, but progress among Gulf Cooperation Council countries has been fairly rapid. Many Gulf Cooperation Council (GCC) indicators are comparable to other non-Western cultural areas. Multiple surveys in Kuwait show fairly widespread acceptance of women in leadership positions. Respondents feel that characteristics of women vs men managers are different, but strengths and weaknesses by gender balance out, so that men and women perform about the same. Traditional Kuwaiti culture seems conducive to women in management, but some specific cultural barriers remain. In particular, the diwaniyya, social gatherings to network and discuss current affairs, and wasta, connections, are dominated by men in modern Kuwaiti society. These are essentially social capital issues.




Practical implications




Fostering continued progress for women in management requires recognition of the actual social and cultural situation; simply arguing that Kuwait should be more Western in how it does things does not seem very useful.




Originality/value




Research on women in management in MENA is not very extensive, but is important for understanding how to facilitate opportunities for women. In Kuwait, there seems to be general acceptance that women can be leaders in managerial positions, and little overt discrimination. However, lack of access to traditional social capital networks puts women at a disadvantage. Research needs to focus on this issue to help develop ways to overcome this subtle obstacle to further progress.

Women in leadership in Kuwait: a research agenda

This paper is intended to highlight the importance of management and administrative ethics in the inception and sustainability of a profound construction company in the Arab world. Osman Ahmed Osman & Coâ„¢ was established in 1947 as a local construction company. The company has gone through 4 pertinent change management phases that shaped and demonstrated its sustainability. It currently exists in 29 countries covering 4 continents with approximately 75 thousand employees (Arab Contractors, 2014). This study hypothesized that management and administrative ethics would lead to success, sustainability, and continuous growth. The research methodology used in this study was a mixed methods approach. A qualitative case study and quantitative survey analyzed the effect of management and administrative ethics on success and sustainability. The findings of this study have been limited to present the continuous growth of the company due to the consistency in applying management and administrative ethics. The study concluded by proposing applying management and administrative ethics to assure the growth and sustainability of any regional or global company.

/pdf/importance-of-management-and-administrative-ethics-on-2n02bcer3m.pdf

Importance of Management and Administrative Ethics on Corporate Success and Sustainability

The present study investigated the extent to which future e-business professionals are being prepared for the technical as well as non-technical aspects of this form of commerce. University technological and nontechnological course content was investigated for 153 e-business degree program curricula based in different parts of the world. Data were collected from university web pages for bachelor’s and master’s degree programs. Courses were categorized according to their focus on the following types of subject matter: technology, ebusiness, or non-technological business skills. Results suggested sampled programs based in North America tended to include more non-technological business coursework while those based in Europe were moving toward more e-business and technical course coverage. Findings further suggest that e-business education could be adapting to local needs and conditions.

http://www.ijbhtnet.com/journals/Vol_4_No_5_October_2014/10.pdf

Athmar Al-Salem

Papers

Sheet flow and suspension of sand in oscillatory boundary layers

Sediment transport in oscillatory boundary layers under sheet-flow conditions

Women in leadership in Kuwait: a research agenda

Importance of Management and Administrative Ethics on Corporate Success and Sustainability

Technology and Business Aspects of E-Business Education