Three-Dimensional Smoothed Particle Hydrodynamics Method for Simulating Free Surface Flows

In this paper, we applied an improved Smoothing Particle Hydrodynamics (SPH) method by using gradient kernel renormalization in three-dimensional cases. The purpose of gradient kernel renormalization is to improve the accuracy of numerical simulation by improving gradient kernel approximation. This method is implemented for simulating free surface flows, in particular dam break case with rigid ball structures and the propagation of waves towards a slope in a rectangular tank.Comment: 9 pages, 5 figures, Selected Paper from the International Symposium on Computational Science 201

The relationship between aquatic macrophytes and water quality in Nta-Wogba Stream, Port Harcourt, Nigeria

An empirical survey of macrophytes distribution and biomass from four stations, along Nta-wogba stream in Port Harcourt, Nigeria, was conducted between April and December 2007, to quantify the relationship between biomass, in stream nutrients and dissolved ions. The correlation analysis indicated that the biomass of the aquatic macrophytes under consideration, Einochloa pyramidalis; Diplazum sammatii; Cyperus difformis; Alternathera sessilis and Ludwigia decurrens were significantly (P<0.05) related to the nutrients: sulphate, ammonium; nitrate, and phosphate in all the stations. The measurement of total dissolved solid, which is correlated to ionic concentrations and turbidity, provided a rough indication of in stream light availability

Simple free-surface detection in two and three-dimensional SPH solver

A simple free-surface particle detection method for two and three-dimensional SPH simulation has been implemented. The method uses sphere representation for the SPH particle. The fluid domain is covered by overlapping spheres. A sphere whose surface is not fully covered considered as boundary. To test particle boundary status, we used a sum of normalized relative position vectors from neighbouring particles to the test particle. By checking the existence of un- covered sphere surface by this vector sum, boundary status of the test particle can be determined. This boundary detection method can be easily embedded in the SPH solver algorithm.Comment: 10 pages, 11 figures, Selected Paper from the International Symposium on Computational Science 201

Pengaruh Lingkungan Kerja, Motivasi Kerja dan Pelatihan terhadap Kinerja Pegawai di Kantor Distrik Bintuni Kabupaten Teluk Bintuni

This research to analyze about how much the influence of the working influence, motivation work and training to the employee performance at the Bintuni District Office of the Teluk Bintuni Regency. This research using the quantitative approach with the explanatory survey method used the quetioner. Variable of this research are the working environment variable (X1), motivation work variable (X2), training variable (X3) to employee performance (Y). The amount of population are the whole of employee, that's are Civil Servant and Honorer amounted 31 employees working at the Bintuni District Office so that become the respondent in this research. The data collection technique with the quetioner using of Likert scala to examining validity and reliability. The resulst of this research showed that the working environment made strong influence to the employee performance showing to the correlation of coeficien is 0,662 and determination of coefisien is 0,438. The motivation work have strong influence to the employee performance with the correlation value is 0,667 and the determination of coeficien is 0,458. The training have a low influence with the correlation of coeficien is 0,606 and the determination of coeficien is 0,36. The working environment, motivation work and training with together have a strong influence to the employee performance with the determination is 0,667. Analysis of this research find out that the working environment and motivation work have a strong influence than the training have a low influence to employee performance at the Bintuni District Office of the Teluk Bintuni Regency

A critical evaluation of labour migrancy and practices of remittances: the case of Ghanaian workers in the informal economy in Johannesburg

ABSTRACT The research was inspired by further studies conducted on remittances indicating that; voluntary migrants worldwide remit generously to their families back home (Adams Jnr. 2006; Mazzucato et al., 2004a; Pendleton et al., 2006; Shady, 2004; Stark, 1991) with little attention paid to Ghanaians involved in labour migrancy in South Africa. This report explored remittance practices by Ghanaian labour migrants involved in the informal economy in Johannesburg and also investigated factors that motivated migrants from Ghana to send money and/or goods back home. The study objectives included identifying channels used to remit, frequency of remittance, different forms of remittances and also investigated the living conditions and nature of work of migrants. Finally, it established why these migrants chose to come to South Africa. A snowball sample was employed to gather data from 20 Ghanaian migrants involved in labour migrancy in the informal economy in Johannesburg. These respondents work at these various places: Parktown, Berea, Yeoville, and Braamfontein and engaged in such work as hairdressing, waiting, tailoring/clothing designing, hairdressing, Internet café operating, welding, barbering, Carpentry, shoe and bag repairing. It therefore appeared that most of these respondents got employed through social networks. Even though it was not the focus of the study, of the total population, 5 females were interviewed to explore their remittance practices compared to their male counterparts. Semi-structured interviews were used to address the research objectives. Though the research revealed two motivating factors namely; economic and social that influenced respondents to sent money to family members, economic factor emerged as the common factor among these migrants. Specific reasons for remitting among the migrants were also categorised as altruism, pure self-interest or “enlightened self-interest”. Further, the survey revealed two channels that were used by these migrants to remit family members back home. These were formal and informal channels. Under the formal channels were specialised money transfer institutions (Standard Bank, Rennies) and then sea freight services. The study saw that majority (75%) of the respondents (all the 5 female migrants inclusive) used the formal channel to transfer money or goods whereas a handful (25%) of the respondents reported to remit through personal contacts which falls under the informal channel. In terms of frequency of remittance, two trends were identified and these were regular and occasional. Migrants who remitted once, twice in every quarter or four months were categorised under regular remitters and among were the 5 female migrants interviewed, while occasional remitters were seen as those who sent money and goods once in 6 months or a year. All respondents reported to have remitted due to economic downturn in Ghana. The data collected highlighted all respondents came to South Africa for jobs that would offer better opportunities because of an impression they (migrants) had on South Africa’s economy