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Sinnar, Sudan

Ajeeb S.,Zhejiang University | Ajeeb S.,Sinnar University | Lv N.,Zhejiang University | Zhang C.,Zhejiang University | And 4 more authors.
Current Nanoscience | Year: 2014

We study the structural instability of gold (Au) and silver (Ag) islands with the size of the order of 103nm on silicone oil surfaces at room temperature. The samples are prepared by the thermal evaporation method. For the Ag system, after the sample is removed from the vacuum chamber, the apparent island coverage of the total area decreases obviously (≥8.0%). As the topological structure of the islands evolves, the decay of the total area of each island may be more than 12%. The microstructure of the Au islands, however, is relatively stable. The interpretation for the experimental results is presented. © 2014 Bentham Science Publishers. Source

Ajeeb S.,Zhejiang University | Ajeeb S.,Sinnar University | Lv N.,Zhejiang University | Zhang C.-H.,Zhejiang University | And 3 more authors.
Philosophical Magazine Letters | Year: 2012

The aggregation behavior of Au atoms and atomic islands on silicone oil surfaces has been systematically investigated by analyzing the evolution of surface coverage. The apparent Au surface coverage increases linearly with the nominal film thickness at low thicknesses and the rate of increase is almost independent of deposition flux. However, as the deposition flux increases, the surface coverage goes up linearly. Further analysis reveals that the deposition flux strongly affects the system free-energy of the island-oil system and therefore the aggregation behavior of the Au atoms and islands. © 2012 Taylor & Francis. Source

Nassrelddin M.Z.A.,Beijing Forestry University | Nassrelddin M.Z.A.,Sinnar University | Wu B.,Beijing Forestry University | Zhang Y.,Beijing Forestry University
Forestry Studies in China | Year: 2012

The present study is an attempt to find a solution for the forest management conflicts existing between local people and the central authoritarian forest services in Sinnar State, Sudan. Sinnar was purposely selected as a study area because 9% (496.4 × 10 3 ha) of the forest reserve area of the entire country is located in this state. A comprehensive survey consisting of field observations, questionnaires and interviews was carried out specifically in the Alsabonabi area for its heterogeneous local community. The results show that the existing management system of the sunt forest reserve (the Alumbwa forest) has failed to support the local people, both residents and semi-nomads. Hence, the present study proposes a series of strategic and organizational changes in order to help in showing the way for integrated and participatory forest resource management and improving the welfare of all impoverished rural communities. © 2012 Beijing Forestry University and Springer-Verlag Berlin Heidelberg. Source

Elsir T.,Wuhan University of Technology | Elsir T.,Sinnar University | Zheng J.,Wuhan University of Technology | Lu H.,Wuhan University of Technology | Wang G.,Wuhan University of Technology
2014 International Conference on Mechatronics, Electronic, Industrial and Control Engineering, MEIC 2014 | Year: 2014

To investigate the backlash phenomenon vibration and noise of a gear transmission system, we compared the performance of two difference types of mechanical transmission performance system: worm gears reducer (DYNABOX) and planetary gear reducer (APEX). We analyzed two kinds of models and harmonic response and evaluated the performance of DYNABOX and APEX reducer based on 3D model and simulation technology. Through the nonlinear dynamic modeling of the transmission system, we established a comparison between DYNABOX and APEEX reducer. From the result of our test platform, we show that the start reduction of APEX reducer in the gears vibration at the mesh total deformation harmonic response is bigger than DYNABOX reducer at the first operation gear mesh, and then stability. Furthermore, the active vibration observed system yield in the planetary gear compared with a worm gear by means of total deformation, stress, strain, and acceleration; shows backlash. Our results revealed that APEX would be an attractive MTPS as compared to DYNABOX. © 2014. The authors - Published by Atlantis Press. Source

Eisa M.O.,Islamic University | Ishag I.A.,Sinnar University | Abu-Nikhaila A.M.,University of Khartoum
Livestock Research for Rural Development | Year: 2010

Data were obtained on 16 camel (Arabi-lahwee) of different age and parity order, maintained at Al-Khalifa Agric. rain feed scheme in El-Showak (Eastern Sudan). The purpose of this study was to determine the udder morphometric of Lahween camel and to find out their correlation with daily milk yield. The result of this study showed that milk yield was 2.7 ± 1.4 liters/day. Udder depth, circumference, vertical semi circumference and size scored 16.9 ± 2.5 cm; 91.4 ± 10.0 cm; 52.0 ± 5.6 cm. and 1559.5 ± 388 cm3., respectively and they were positively correlated with daily milk yield. While udder height at fore and rear quarters and udder levelness were 111 ± 7.1 cm; 110 ± 7.6 cm and 1.6 ± 1.6 cm., respectively, and they were negatively correlated with daily milk yield. Length of fore and rear teats and distance between right teats and that between left teats were 4.3 ± 1.4 cm; 4.4 ± 1.5 cm; 3.1 ± 1.8 cm and 3.0 ± 1.5 cm, respectively and they were positive and significantly correlated with daily milk yield (P<0.05; r= 0.34, 0.36, 0.65 and 0.34, respectively). Milk vein length and diameter were 88.0 ± 7.7 cm and 1.8 ± 0.5 cm., respectively, and positively correlated with daily milk yield (P>0.05). Morphologic change in the measurements of udder depth, udder height, teat diameter and distances between teats before and after milking were statistically significant (P<0.01) and may indicate to greater milk secretion potential of Lahween camel. Source

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