Single-, Dual- and Triple-band Frequency Reconfigurable Antenna

The paper presents a frequency reconfigurable slot dipole antenna. The antenna is capable of being switched between single-band, dual-band or triple-band operation. The antenna incorporates three pairs of pin-diodes which are located within the dipole arms. The antenna was designed to operate at 2.4 GHz, 3.5 GHz and 5.2 GHz using the aid of CST Microwave Studio. The average measured gains are 1.54, 2.92 and 1.89 dBi for low, mid and high band respectively. A prototype was then constructed in order to verify the performance of the device. A good level of agreement was observed between simulation and measurement

Effects of Controller and Nonuniform Temperature Profile on the Onset of Rayleigh-Bénard-Marangoni Electroconvection in a Micropolar Fluid

Linear stability analysis is performed to study the effects of nonuniform basic temperature gradients on the onset of Rayleigh-Bénard-Marangoni electroconvection in a dielectric Eringen’s micropolar fluid by using the Galerkin technique. In the case of Rayleigh-Bénard-Marangoni convection, the eigenvalues are obtained for an upper free/adiabatic and lower rigid/isothermal boundaries. The influence of various parameters has been analysed. Three nonuniform basic temperature profiles are considered and their comparative influence on onset of convection is discussed. Different values of feedback control and electric number are added up to examine whether their presence will enhance or delay the onset of electroconvection

Pengaruh Asap Rokok Kretek Terhadap Imunitas Seluler Tikus Betina Strain Lmr

Experimental research was done to understand the effect of cigarette smoke to cellular immunity. In this research, 3 groups of rats were exposed by cigarette smoke for 7, 14, and 21 estrous cycles. Each group had a control group that was not exposed by cigarette smoke. Percentage of T lymphocytes blastransformation that cultured in 72 hours was used as the parameter. T Lymphocytes blastransformation was measured with the blood culture preparation. The result showed the groups exposed in 7 and 14 cycles had no significant influence in cellular immunity. But the groups exposed in 21 cycles showed a decline of the cellular immunity function. This research has provided that the cellular immunity of the rats declines by the cigarette smoke in 21 cycle's exposure. Based on this research, people who are exposed by cigarette smoke for long time can decrease of their immunity, especially cellular immunity

Logam Berat, Radiasi, Diet, Rokok, Alkohol, Dan Obat-obatan Sebagai Penyebab Infertilitas Pria

Infertility on male can be cause by some factors such as heavy metal, radiation, diet, cigarette, alcohol, and drugs. Heavy metals that often related to influence the process of spermatogenesis are plumbum and cadmium. Radiation on the high intensity can destroy sperm or mutation. Consumption of cortisone and leptin in the large number will influence the production of FSH and LH that will decrease the quantity of sperm. Cigarette smoker can decrease the quantity or sperm quality on active and passive smoker. While alcohol and drugs can decrease the fertility of male through interference on reproductive hormone system. Hormonal interferences can cause/effect on spermatogenesis, so that caused decreased quality or quantity of sperm

Impact of Arrivals on Departure Taxi Operations at Airports

Aircraft taxi operations are a major source of fuel burn and emissions on the ground. Given rising fuel prices and growing concerns about the contributions of aviation to air pollution and greenhouse gas emissions, recent research aims to develop strategies to reduce fuel burn at airports. In order to develop such strategies, an understanding of taxi operations and the factors that affect taxi-out times is required. This paper describes an analysis of taxi-out times at two major U.S. airports in order to identify the primary causal factors affecting the duration of taxi-out operations. Through an analysis of departures out of John F. Kennedy International Airport and Boston Logan International Airport, several variables affecting taxi-out times were identified, including primarily the number of arrivals and number of departures during the taxi-out operation of an aircraft. Previous literature suggests that the number of arrivals on the surface has limited influence on taxi-out times; however, this analysis demonstrates that the number of arrivals is in fact significantly correlated with taxi-out times. Furthermore, we find that arrivals have a greater impact on taxi-out times under runway configurations where there is increased interaction between arrivals and departures

Analisis Pertumbuhan Tanaman Kayu Putih (Melaleuca Cajuputi Sub SP. Cajuputi) pada Kawasan Hutan Lindung Dusun Malimbu dan Dusun Badung Resort Malimbu Kphl Rinjani Barat

Tujuan penelitian ini adalah untuk mengetahui faktor karakteristik lahan yang mempengaruhi perbedaan pertumbuhan Kayu Putih di Malimbu dan Badung dan menentukan Kelas kesesuaian lahan Kayu Putih di Malimbu dan Badung. Penelitian ini dilakukan di kawasan hutan lindung Dusun Malimbu dan Badung Resort Malimbu KPHL Rinjani Barat. Parameter yang diukur adalah pertumbuhan Kayu Putih meliputi diameter, tinggi dan volume, serta faktor lingkungan meliputi ketinggian tempat, suhu udara, dan sifat fisika tanah (tekstur tanah, kadar air tanah, kedalaman efektif, bulk density, porositas tanah dan suhu tanah). Hasil penelitian menunjukkan bahwa ׃ 1). Rata-rata diameter, tinggi, volume dan jumlah tanaman Kayu Putih umur 22 bulan di Badung sebesar 3,33 cm, 3,29 m, 2355,83 cm3 dan 32 tanaman/plot, sedangkan di Malimbu sebesar 1,43 cm, 1,87 m, 241,85 cm3 dan 22 tanaman/plot; 2). Faktor yang berpengaruh nyata pada taraf toleransi 95% (α = 0,05) terhadap diameter Kayu Putih adalah fraksi pasir, suhu tanah, kedalaman efektif dan ketinggian tempat, sedangkan terhadap tinggi Kayu Putih adalah fraksi pasir, bulk density dan kedalaman efektif; 3). Kesesuaian lahan aktual Kayu Putih di Malimbu tergolong Kelas N1r dengan faktor pembatas media perakaran (drainase tanah), sedangkan di Badung tergolong Kelas S3w dan S3wr dengan faktor pembatas ketersediaan air (bulan kering) dan media perakaran (drainase tanah)

Wide to multiband elliptical monopole reconfigurable antenna for multimode systems applications

Wideband-multiband reconfigurable elliptical monopole antenna is investigated in this paper. By having conventional elliptical monopole antenna, wideband operating frequency is obtained. With the combination of dual pairs of slotted arms and a band-pass filter on the ground plane of the elliptical monopole, multiband is achieved. Dual-band operating frequencies at 1.6 GHz and 2.6 GHz while wideband operates from 3.35 GHz to 9 GHz. Therefore, wide range of wireless communication systems is obtained from the proposed antenna to support the multiband mode (i.e. GPS and LTE) and UWB systems. Frequency reconfigurable is achieved by controlling the switches integrated on the antenna structure. Simulated results of reflection coefficient, radiation patterns and gain performance are presented. The proposed antenna design is suitable candidate for different wireless communication applications

Ibm Peningkatan Produktivitas Kelompok USAha Roti “Nenot-nenot” Kelurahan Suka Ramai Medan

Persaingan industri roti sekarang ini semakin meningkat dalam memenuhi permintaan pasar. Para USAha kecil menengah mereka berlomba untuk memenuhi permintaan pasar tersebut. Dari segi proses pembuatannya, Mitra IbM (Iptek bagi Masyarakat) tidak menggunakan bahan tambahan agar harga jual roti dapat menjadi murah dan terjangkau. Ditemukan beberapa permasalahan dalam peningkatan produktivitas pada mitra antara lain: kelemahan dalam penyusunan anggaran biaya operasional sehingga sulit menentukan perencanaan anggaran dan laporan keuangan secara cepat. Permasalah persediaan bahan baku yang tidak tepat karena mengandalkan make to order sering stock bahan baku habis atau terbatas sehingga permintaan konsumen dan pelanggan jadi terganggu, permasalahan selanjutnya adalah rancangan fasilitas kerja pada stasiun kerja pembentukan (terdiri dari pengerjaan pengadukan, penipisan adonan, pengisian, pembentukan) yang tidak ergonomis, dengan metode kerja yang tidak efektif yang mengakibatkan para pekerja sering kelelahan dalam memproduksi roti sehingga produktivitas menurun. Permasalahan lainnya yang ditemui adalah rancangan alat bantu untuk mengurangi musculoskeletal dibagian pemanggangan akibat aktivitas angkat angkut yang dilakukan secara manual, permasalahan selanjutnya yang ditemui adalah lemahnya motivasi kerja para pekerja, lemahnya strategi bauran promosi dibandingkan kompetitor kecil dan besar lainnya. Berdasarkan uraian diatas untuk menyelesaikan permasalahan yang dihadapi kelompok USAha roti \u27nenot-nenot\u27 perlunya USAha peningkatan produktivitas dari berbagai lini produksi sampai bauran promosi Mitra. Untuk itu melalui program IbM maka dirancang dan dibuat teknologi tepat guna serta pelatihan untuk membantu kelompok USAha roti agar adanya peningkatan aspek produksi dan manajemen USAha yang baik. Hasil pelaksanaan IbM menunjukkan Pemilik USAha roti dan pekerja Mengetahui peran ergonomi dan teknik tata cara kerja dalam mengevaluasi dan merancang suatu sistem kerja yang terdiri dari manusia dan mesin. Pemilik USAha roti dapat mempertahankan stabilitas atau kelancaran kegiatan operasi bakery, sehingga bakery masih dapat memenuhi permintaan pasar serta mampu melakukan perbaikan terhadap postur kerja operator yang salah atau kurang ergonomis dan keberhasilan juga terlihat dengan Meningkatnya produktivitas dan penampilan kerja