900 research outputs found
Optimisation des paramètres de dépôt de a-Si:H dans la technique Hg-photo-CVDK
Optimizing deposition parameters of a-Si:H in Hg-photo-CVD technology The Hg-photo-CVD technique, known for its use in eveloping thin film of semiconductor materials and dielectrics has been a resurgence of interest in view of their many applications in microelectronics. It is established that the physico-chemical and optoelectronic material filed in this case the hydrogenated amorphous silicon (a-Si: H) are a function of preparation conditions, including substrate temperature, the pressure of reactive gases, their speed, light intensity, temperature of reaction medium, temperature of the mercury and temperature of the post-deposition annealing.We highlight in this article which is a review of our work in this area, the conditions for optimization of key arameters of deposition : Mercury Temperature T HG : about 50° C - substrate temperature Ts : 250 to 300 °C - Reactive gas pressure : around 1 Torr - gas flow reagent : 1 to 5 sccm (or cm3 / s) - The nominal light intensity : 10 to 20 mW/cm2, temperature of post-deposition annealing: about 300 ° C for 30 minutes. At Ts = 280 °C, the photosensitivity is optimized to a value of more than 103. In the optimal working conditions proposed, conversion of the reactive gas in silicon is streamlined and the large amount of hydrogen formed, for security reasons, become as the carrier gas for the evacuation of the gas mixture
Pre-commitment mechanism and policy credibility in African trade reform
The issue of the credibility of economic policies has been the topic of many studies since the 1970s. While the theory is quite well established, little work has so far been done on its empirical applicability. This dissertation first develops a two-game model: the pre-commitment game and the time consistent game to show that, in the absence of a pre-commitment mechanism, a government\u27s ex-ante optimal tariff choice is different from its ex-post optimal choice. We show that because of the subgame imperfection of the pre-commitment solution, forward looking private agents will find the announcement of a trade reform policy by the government at the beginning of the pre-commitment game to be time inconsistent, and therefore not credible. We further show that a pre-commitment mechanism is required to enhance the credibility of the pre-commitment solution and we propose such a mechanism that could be applied in developing countries;But it is the empirical investigation of the dissertation that constitutes its real contribution to the literature. Indeed, using data from eight African countries, we examine whether international agreements, such as the World Bank/IMF sponsored Structural Adjustment Programs, can serve as pre-commitment mechanisms which could bolster policy reforms announcements in Africa;The bootstrap technique is used to test for the real effects of adjustment agreements signed by African nations with the Bretton Woods institution on actual tariff policy. The results of the test show that we cannot reject the null hypothesis that African governments\u27 precommitment policies had an impact on their actual tariff policies. Further, we estimated a trade flow equation, which allowed us to examine the response of the private sector to the adjustment process in Africa. Using a fixed effects approach to panel data modeling, we are able to determine country specificity in each of our empirical models;Overall, our results show that between the pre- and post-agreements periods there occurred a structural break in both the tariff and the trade models. We obtain statistical evidence that in general, African governments adhered to the announced policy reforms. But this implementation was not perfect, as reversals occurred in later years of adjustment in many countries. We also obtain clear evidence that the trade response of the private sector to the adjustment programs was positive, for the results show that there occurred a statistically significant increase in trade flows in the adjustment period. We believe that these results indicate that the private sector generally lent credence to policy adjustments in Africa. We conclude that programs such as the structural adjustment programs undertaken in Africa in the 1980s can serve as pre-commitment mechanism for government policy making, but these programs must be developed firmly on the basis of the social, political and cultural realities of each country
Towards a Compensatory Approach to Redressing Constitutional Violations in Botswana
A legal analysis on how the constitution of Botswana can adopt a compensatory approach to address citizens grievances when their constitutional and basic rights have been abused.Constitutions of most, if not all, civilised countries contain elaborate provisions on fundamental rights and freedoms of the individual. These are normally entrenched in a Bill of Rights and operate to delineate a general locus of individual liberties and entitlements which the government must not encroach upon without serious justification. Where the fundamental rights are violated redress must be provided to the victims.
For Botswana, basic freedoms of the individual are entrenched under Chapter II* 1 of the Constitution. They can be enumerated broadly to include,
(a) Life, liberty and security of the person.
(b) Freedom of conscience, expression, assembly and association.
(c) Privacy and protection from deprivation of property without compensation
Tradisi Salai Jin Sebagai Modal Sosial Masyarakat Tidore Kepulauan
The Tidore people are people who still adhere to the traditions passed down by their ancestors. One of the traditions in question is the Salai Jin ritual. Viewed from the aspect of social relations, this tradition characterizes social interaction between people. The Salai Jin ritual is basically a ritual which, according to local people's beliefs, allows communication between humans and supernatural beings with various purposes. Among the purposes of this ritual is to establish cooperation to ensure safety and health. The researcher is interested in examining (1) the values of the Salai Jin ritual as one of the social assets of the Tidore archipelago community, and (2) the meaning and internalization of the values of the Salai Jin ritual in the social life of the Tidore archipelago community. Designed as a descriptive qualitative research, data were collected through interviews, observation, and documentation. Meanwhile, triangulation is used to validate research data. After the data has been analyzed using data reduction techniques, data presentation, and drawing conclusions, this study captures several social phenomena related to the Salai Jin ritual in the Tidore Islands community, including, (1) the Salai Jin ritual contains values of togetherness, bari (mutual cooperation), empathy, and social care, and (2) the meaning of these values is to build good communication and cooperation based on the values and norms prevailing in society. The actualization of the Salai Jin ritual as social capital can be found in various mutual cooperation activities such as building houses, wedding celebrations, dina (the tradition of commemorating those who have died), and other community social activities
Reliability of steel structures in case of fire
Na primjeru čelične krovne konstrukcije sportske dvorane „Spaladium“ u Splitu prikazan je novi način proračuna nosive konstrukcije na djelovanje požara u velikim zatvorenim prostorima sukladno Eurokodu. Modelom zona dobiveni su odnosi temperatura-vrijeme u zatvorenom prostoru i to za dvije požarne situacije: požar na borilištu i požar na tribinama. Na temelju krivulja temperatura-vrijeme u nosivim elementima čelične konstrukcije analizirana je pouzdanosti krovne konstrukcije.A new method for analyzing fire resistance of load bearing structures in big indoor spaces, based on Eurocode, is presented through case study of the steel roof structure of the Spaladium Sports Hall. The temperature-time relationships for indoor space are obtained by the zone model, and this for two fire situations: fire in the arena, and fire on the grandstand. The reliability of the roof structure is analyzed based on temperature-time curves in load-bearing elements of the steel structure
Combining indoor residual spraying with chlorfenapyr and long-lasting insecticidal bed nets for improved control of pyrethroid-resistant Anopheles gambiae: an experimental hut trial in Benin.
BACKGROUND: Neither indoor residual spraying (IRS) nor long-lasting insecticidal nets (LLINs) are able to fully interrupt transmission in holoendemic Africa as single interventions. The combining of IRS and LLINs presents an opportunity for improved control and management of pyrethroid resistance through the simultaneous presentation of unrelated insecticides. METHOD: Chlorfenapyr IRS and a pyrethroid-impregnated polyester LLIN (WHO approved) were tested separately and together in experimental huts in southern Benin against pyrethroid resistant Anopheles gambiae and Culex quinquefasciatus. The bed nets were deliberately holed with either six or 80 holes to examine the effect of increasing wear and tear on protectiveness. Anopheles gambiae were genotyped for the kdr gene to assess the combination's potential to prevent the selection of pyrethroid resistance. RESULTS: The frequency of kdr was 84%. The overall mortality rates of An. gambiae were 37% and 49% with the six-hole and 80-hole LLINs, respectively, and reached 57% with chlorfenapyr IRS. Overall mortality rates were significantly higher with the combination treatments (82-83%) than with the LLIN or IRS individual treatments. Blood feeding (mosquito biting) rates were lowest with the 6-hole LLIN (12%), intermediate with the 80-hole LLIN (32%) and highest with untreated nets (56% with the 6-hole and 54% with the 80-hole nets). Blood feeding (biting) rates and repellency of mosquitoes with the combination of LLIN and chlorfenapyr IRS showed significant improvement compared to the IRS treatment but did not differ from the LLIN treatments indicating that the LLINs were the primary agents of personal protection. The combination killed significantly higher proportions of Cx. quinquefasciatus (51%, 41%) than the LLIN (15%, 13%) or IRS (32%) treatments. CONCLUSION: The chlorfenapyr IRS component was largely responsible for controlling pyrethroid-resistant mosquitoes and the LLIN component was largely responsible for blood feeding inhibition and personal protection. Together, the combination shows potential to provide additional levels of transmission control and personal protection against pyrethroid-resistant mosquitoes, thereby justifying the additional resources required. Chlorfenapyr has potential to manage pyrethroid resistance in the context of an expanding LLIN/IRS strategy
Numerical model for determining fire behaviour of structures
U radu je prikazan numerički model i razvijeni računalni program za predviđanje ponašanja konstrukcija uslijed djelovanja požara. Nelinearni numerički postupak provodi se u zadanim vremenskim inkrementima, pri čemu se u svakom inkrementu proračunava razdioba temperature, u ovisnosti o njoj korigiraju karakteristike materijala i krutost elementa te rješava statički problem. Na jednostavnom primjeru čeličnog grednog nosača prikazana je efikasnost i točnost razvijenog modela i računalnog programa.A numerical model and computer program for predicting behaviour of structures subjected to fire action are presented in the paper. The nonlinear numerical procedure is conducted in pre-defined time increments. At that, the distribution of temperature is calculated in each increment and, depending on this calculation, material properties and stiffness of the element are corrected, and the static problem is resolved. The efficiency and accuracy of the model and computer program are presented on an example of a simply supported beam
IMPLEMENTASI DAN ANALISA KINERJA ALGORITMA ANT SYSTEM (AS) DALAM PENYELESAIAN MULTIPLE TRAVELLING SALESMAN PROBLEM (MTSP)
Penelitian ini bertuiuan untuk membangun dan menganalisa kinerja suatu sistem algoritma Ant System (AS)
untuk penyelesaian Multiple Travelling Salesman Problem (MTSP). WSP odalah periasalahan disiibusi yang
membutuhkan lebih dqri satu salesman untuk mengunjungi sejumlah titik dqn kembali ke titik awal. Sistqs dibangun dengan menggunakan pemrograman Delphi 7 dan dstabqse IzIySQL. Hasil dari keseluruhan proset pada sistem ditampilkan dalam bentuk teks maupun visuqlisasi yang menunjukkan rute perjalanan dari setiq salesman. Sistem ini cukup efedif dalam penentuan rute dan jarak minimum untui pirmasalahan It[Iip tersebut. Pengujian dengan kasus-kasus yang berbeda menunjukkan adanya p"ngo*i iumlah
sqlesman dan nilai parameter (a, p dan p) terhadap performa algoritma
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