Numerical Approach of the Influence of Geometric Properties on the Absorbing in Photonic Crystal

In the proposed study, an investigation has been carried out in order to find a material efficient structure, capable of harnessing maximum solar spectrum. A material efficient structure designed using a one dimensional photonic crystal (1D PC) for amorphous silicon. Silicon material is used as it leads to environmental friendly design. The principal objective of this study is to maximize the photon absorption, keeping reflection to a minimum. The influence of geometric parameters on the absorption is studied by using the Finite element method (FEM). The results show that the absorption is affected by the geometry parameters. The optimum parameters of the proposed structure are period (a = 480 nm), a filling factor (ff = 50 %) and depth (d = 150 nm). The increase of absorption in the lower region where the wavelengths are around 480 nm, is explained by the reduction of the effective index resulting from the structure of the absorbent layer. For wavelengths between 480 nm and 600 nm, the absorption is directly related to existing Fabry-Perot modes within the absorbent layer. Creating additional absorption peaks at wavelengths above about 600 nm weakly absorbed normally comes from the coupling of the incident light with slow Bloch modes of PC located above the light line

Synchronous machine parameter identification in frequency and time domain

This paper presents the results of a frequency and time-domain identification procedure to estimate the linear parameters of a salient-pole synchronous machine at standstill. The objective of this study is to use several input signals to identify the model structure and parameters of a salient-pole synchronous machine from standstill test data. The procedure consists to define, to conduct the standstill tests and also to identify the model structure. The signals used for identification are the different excitation voltages at standstill and the flowing current in different windings. We estimate the parameters of operational impedances, or in other words the reactance and the time constants. The tests were carried out on synchronous machine of 1.5 kVA 380V 1500 rpm

RANCANG BANGUN ALAT PEMIPIH BIJI JAGUNG OLAHAN

Jagung merupakan salah satu hasil pertanian di indonesia yang memilikibanyak kandungan gizi. Untuk memanfaatkan jagung tersebut maka dibuatlah alatpemipih biji jagung yang dapat dimanfaatkan di kalangan masyarakat. Pembuatan alatyang sebelumnya telah dibuat dengan ketebalan + 1,0 mm.Oleh karena itu, pembuatanalat ini dilakukan untuk mengetahui bagaimana menghasilkan pemipihan jagung yangketebalannya bervariasi+ 1, + 1,5 dan + 2 mm, membuat alat pemipih jagung yangminimalis dan mudah dioperasikan serta bagaimana mengetahui biaya pembuatanalat pemipih biji jagung olahan ini. Berdasarkan hasil pengujian hasil pemipihan yangdiperoleh untuk ketebalan + 1,0 mm yang diambil dari 10 sampel pengujian yangdiambil secara acak yakni rata – rata 1,01 mm, 1,08 mm, dan 1,07 mm selama 3 kalipercobaan. Sedangkan hasil pemipihan yang diperoleh untuk ketebalan + 1,5 mmyang diambil dari 10 sampel pengujian yang diambil secara acak yakni rata – rata 1,52mm, 1,62 mm, dan 1,56 mm selama 3 kali percobaan. Serta hasil pemipihan yangdiperoleh untuk ketebalan + 2,0 mm yang diambil dari 10 sampel pengujian yangdiambil secara acak yakni rata – rata 2,09 mm, 2,02 mm, dan 2,05 mm selama 3 kalipercobaan.Adapun hasil dari analisis, maka waktu pengeringan berpengaruh padawaktu proses pemipihan, dimana menunjukkan bahwa semakin lama di jemursemakin cepat proses pemipihan dan sedikit berpengaruh pada hasil pemipihan

Effectiveness of teleworking using internet facilities (E-Teleworking)

Teleworking offers alternatives for people to work without concerning their geographical boundary or time zone. Work can be performed anywhere and anytime without restriction.Teleworking tends to be the trend in the world of business.However, in spite of its popularity, Malaysia is still lagging behind in its implementation.Telecommunication technology is the key factor in contributing to the successful implementation of teleworking.In order to carry out the task of teleworking,a variety of telecommunication facilities are available.However, nowadays, only one approach is considered effective that is using the Internet facilities (e-teleworking).The main objective of the research is to evaluate the effectiveness of e-teleworking. In depth literature review had been done in recognizing the traits of teleworking that can be implemented using Internet facilities.A prototype of e-teleworking had been developed as a tool in the evaluation phase. The findings had proven that Internet facilities are indeed one of the most effective alternatives in performing teleworking

Introduksi Model Ptt dalam Meningkatkan Produksi dan Pendapatan Petani Padi di Sulawesi Tengah

It is still possible to improve potential yield of rice in Central Sulawesi. One of efforts to increase yield isthrough Integrated Rice Crop Management (PTT), namely managing crop, soil, water, and soil nutritional elements toimprove crop growth, and higher, sustainable yield. Results of PTT were promising. Rice yield increased from 3.5tons/ha (Non PTT) to 6 tons/ha (PTT) with farm income of Rp 4,617,500/year and B/C ratio of 1.56. Total productioncost of Non-PTT farmers and PTT farmers were each of Rp 4.1 million/ha and Rp 3.2 million/ha.Key words : rice, integrated farming system, production, income, Central Sulawesi Pencapaian produksi rata-rata padi sawah di Sulawesi Tengah relatif masih jauh dari potensi genetik yangdimiliki oleh tanaman padi (yield gap), sehingga masih terdapat cukup besar peluang untuk meningkatkan produksipadi. Upaya peningkatan produksi padi dilakukan melalui pendekatan model Pengelolaan Tanaman Padi secaraTerpadu (PTT) yakni mengelola tanaman, tanah, air dan unsur hara secara terintegrasi untuk mendapatkanpertumbuhan tanaman yang lebih baik, serta hasil yang lebih tinggi dan berkelanjutan. Hasil yang dicapai dariintroduksi model PTT ini sangat menggembirakan dan membuka harapan yang besar bagi peningkatan produktivitasdan pendapatan USAhatani padi. Peningkatan hasil gabah yang diperoleh sangat signifikan yakni dari rata-rata produksigabah non-PTT sekitar 3,5 t/ha meningkat hingga 6 t/ha dengan pendapatan sebesar Rp 4.617.500/tahun dan nilai B/Csekitar 1,56. Sementara total biaya produksi dari sistem USAhatani menggunakan model PTT tidak terlalu jauhberbeda dibandingkan cara petani non-PTT, yaitu Rp. 4,1 juta/ha dibanding Rp. 3,2 juta/ha pada non-PTT

Determination of Phenolic and Flavonoid Contents, Antioxidant Activities and GC-MS Analysis of Clinacanthus Nutans (Acanthaceae) in Different Locations

Clinacanthus nutans is an essential medicinal plant that had been used in various local remedies to treat many illnesses. A study had been conducted to determine the phenolic, flavonoid, antioxidant activities and phytochemical compounds of C. nutans in different locations. C. nutans were harvested from eight locations and the leaves were extracted with 80 % methanol by maceration process. Then, the phytochemical screening using Gas Chromatography-Mass Spectrometry (GC-MS), 2,2 diphenyl-2-picrylhydrazyl hydrate (DPPH) assay method, total phenolic content by Folin Ciocalteu\u27s assay method and total flavonoid content by aluminium chloride (AlCl3) were carried out. The C. nutans extracts showed higher antioxidant activities than phenolic and flavonoid content. The neutral pH sandy clay soil from location KKK (Kuala Ketil, Kedah, Malaysia) had higher antioxidant activities (58.0 %), phenolic (44.1 mg GA.100 g-1) and flavonoid content (30.8 mg QE.100 g-1) compared to other locations. The GC-MS analysis showed the presence of phytochemicals constituents of 20 compounds. The results revealed that environmental factors (light intensity, temperature and soil characteristics) of eight locations were responsible for variations of phenolic, flavonoids, antioxidants and GC-MS analysis in C. nutans. The findings of this study will provide baseline data for future breeding programs for commercial cultivation

Investigation of Potential Grounding Compound for Portable Applications

This paper applies to the electrical engineering world by making earthing system portable in providing low and acceptable resistance path. The system is develop in a small scale portable earthing system against the massiveness of Earth and becomes leverage if soil at the place is not suitable for plant grounding system. Hence, this paper presents findings on the research of new grounding medium material that will be housed in a small scale enclosure which behaves like native earth related earthing system by using kaolin and bauxite. The data obtained from lightning flashover testing, morphological and chemical composition of material analysis indicated that bauxite is more useful for portable grounding system application much better than kaolin in term of zero reference point function. The portable earthing system can be apply to air aviation systems , railway systems and military sectors particularly for electronic equipment zero referencing

Eccentric connectivity index of some chemical trees

Let G = (V, E) be a simple connected molecular graph. In such a simple molecular graph, vertices represent atoms and edges represent chemical bonds, we denoted the sets of vertices and edges by V(G) and E(G), respectively. If d(u, v) be the notation of distance between vertices u, v ε V(G) and is defined as the length of a shortest path connecting them. Then, the eccentricity connectivity index of a molecular graph G is defined as ζ(G) = Σ vεv(G) deg(v)ec(v), where deg(v) is degree of a vertex v ε V(G), and is defined as the number of adjacent vertices with v. ec(v) is eccentricity of a vertex v ε V(G), and is defined as the length of a maximal path connecting to another vertex of v. In this paper, we establish the general formulas for the eccentricity connectivity index of some classes of chemical trees