Hasil Pencarian  ::  Simpan CSV :: Kembali

"The photocatalytic degradation of methylcyclohexane (MCH) in two phases (aqueous and vapor) was examined using modified titania that was immobilized on pumice and performed in the system of a specific condition. The photodegradation system that used a particular configuration reactor and modified catalyst could facilitate the two-phase photodegradation of MCH simultaneously. The photocatalyst was prepared by the mechanical mixing of urea and TiO2 P25 with mass ratios of 1:3 and 2:3, respectively and then calcined at 350 and 450oC. This modified photocatalyst was then immobilized on pumice and finally used for the photodegradation of MCH. The Infrared spectra studies revealed that modified titania with urea successfully incorporated a non-metal dopant within the TiO2 lattice. The catalyst that spread evenly across the surface of the pumice can be seen from Scanning Electron Microscope (SEM) characterization. The loading of 7.5% mass photocatalyst that immobilized on pumice degraded MCH in two-phases simultaneously during a 120 minute period and can be considered the optimum condition."

"The photocatalytic degradation of methylcyclohexane (MCH) in two phases (aqueous and vapor) was examined using modified titania that was immobilized on pumice and performed in the system of a specific condition. The photodegradation system that used a particular configuration reactor and modified catalyst could facilitate the two-phase photodegradation of MCH simultaneously. The photocatalyst was prepared by the mechanical mixing of urea and TiO2 P25 with mass ratios of 1:3 and 2:3, respectively and then calcined at 350 and 450oC. This modified photocatalyst was then immobilized on pumice and finally used for the photodegradation of MCH. The Infrared spectra studies revealed that modified titania with urea successfully incorporated a non-metal dopant within the TiO2 lattice. The catalyst that spread evenly across the surface of the pumice can be seen from Scanning Electron Microscope (SEM) characterization. The loading of 7.5% mass photocatalyst that immobilized on pumice degraded MCH in two-phases simultaneously during a 120 minute period and can be considered the optimum condition."

"Antenna can be one of the largest components in a wireless device; therefore antenna miniaturization can reduce the overall size of wireless devices. One method used to reduce the element size of an antenna is by using metamaterial structures. This paper discusses a Left-Handed Metamaterial (LHM) structure stacked on a two-element microstrip antennas array for miniaturization and gain enhancement at a frequency of 2.35 GHz. To observe the impact of the LHM structure on the antenna, first this paper discuss the design of a conventional rectangular shape microstrip antenna without a LHM structure, then a design of the LHM structure which shows both negative permittivity and negative permeability. This LHM structure is then implemented on a conventional single element microstrip antenna and on a two-element microstrip antennas array. Results and discussion of implementation of the LHM structure on the conventional microstrip antenna is provided in this paper.

The results show that good agreement between simulated and measured results has been achieved. The simulation results show that the antenna works at a frequency of 2.29?2.42 GHz with a bandwidth of 128 MHz (5.4%) and a gain of 8.2 dBi, while the measurements show that the antenna works at a frequency of 2.26?2.41 GHz with a bandwidth of 146 MHz (6.21%) and a gain of 8.97 dBi. In addition, by comparing the substrate dimension for the two element array antennas, with and without the LHM structure, shows a 39% reduction is achieved."

"Anggaran pengangkutan endapan terampai sungai lazimnya berdasarkan kepadapertalian antara beban ampaian dengan luahan, tetapi pertalian ini agak lemah dan selalunyasukar untuk diukur terutamanya semasa kejadian aliran ribut. Extrapolasi menggunakan luahanmelalui persampelan regular melibatkan banyak ralat. Satu pendekatan alternatif ialah denganmelakukan persampelan semasa kejadian siri ribut menggunakan alat persampelan automatik.Namun ini memerlukan belanja yang besar dan melibatkan banyak sampel yang perlu dianalisis.Sebagai respons kepada masalah ini, pertalian antara kepekatan endapan terampai dengankekeruhan memberikan satu kaedah yag cepat dan murah. Satu kajian bermula daripada Oktober2001 hingga October 2002 yang melibatkan persampelan dan pengukuran luahan setiap duaminggu dan dua persampelan intensif (1-4 Oktober 2001 and 11-12 Oktober 2001) di jalankan didua batang sungai kecil di Utara Perlis. Keputusan kajian ini mempamerkan pertalian yang kuatantara kepekatan endapan terampai dengan kekeruhan dan sebaliknya. Pertalian positif ini menjadikan parameter kekeruhan itu sebagai indikator yang terbaik bagi kepekatan endapanterampai dalam penganggaran pengangkutan endapan terampai sungai. "

"ABSTRAKThe field of electrical engineering is inseparable from mathematics. One of the commonly used equations is differential equations, in both linear and nonlinear form. Solution of linear equations of differential equations can be obtained analytically, but the solution of nonlinear differential equations can not be easily obtained.The solution of the differential equation is necessary solved to understand the behavior of the dynamic system, therefore in the proses of simulation, a special method is required which can provide these numerical differential equations solution. This can be done with Matlab-Simulink programming.Matlab-Simulink software with version R2016a provides LIBRARY BROWSER facility which is very adequate and applied in windows system, and has LIBRARY which consist of many blocks; CONTINUOUS blocks, DISCONTINUITIES blocks, MATH OPERATIONS blocks, FUNCTION, SOURCES blocks, SINKS blocks and so on. Therefore the solution of a system that has a linear or nonlinear differential equation is very necessary to be disclosed."