Quadrature Phase Shift Keying (QPSK) Modulator Design using Multi-Port Network in Multilayer Microstrip-Slot Technology for Wireless Communication Applications

The design of the quadrature phase shift keying (QPSK) modulator by using a multi-port network is proposed in this article for the use in wireless communication applications. The multi-port network is in the form of multilayer microstrip-slot technology. This multi-port network is composed of three 3-dB rectangular-shaped directional couplers with virtual stubs and an equal power division divider with in-phase characteristic. The design is performed by applying a full-wave electromagnetic simulation software, CST Microwave Studio (CST MWS). Keysight’s Advanced Design System (ADS) is applied in analyzing and evaluating the QPSK constellation of the proposed modulator. This comparatively small size of proposed design has been fabricated, and its wideband performance of 2 to 6 GHz is verified

Modeling of the minimized two-phase flow frictional pressure drop in a small tube with different correlations

The major parameters of interest in heat transfer research are the refrigerant charge, pressure drop, and heat transfer capacity. Smaller channels reduce the refrigerant charge with higher heat transfer capability due to the increased in surface area to volume ratio but at the expense of a higher pressure drop. Differences between the predicted and experimental frictional pressure drop of two-phase flow in small tubes have frequently been discussed. Factors that could have contributed to that effect have been attributed to the correlations used to model the flow, some being modified from the originals developed for a macro system. Experimental test-rigs have varied in channel geometry, refrigerant type, and flow conditions. Thousands of data have been collected to find a common point among the differences. This paper reports an investigation of four different two-phase friction factor correlations used in the modeling of the frictional two-phase flow pressure drop of refrigerant R-22. One had been specifically developed for laminar flow in a smooth channel, another was modified from a laminar flow in a smooth pipe to be used for a rough channel, and two correlations are specific for turbulent flow that consider internal pipe surface roughness. Genetic algorithm, an optimization scheme, is used to search for the minimum friction factor and minimum frictional pressure drop under optimized conditions of the mass flux and vapor quality. The results show that a larger pressure drop does come with a smaller channel. A large discrepancy exists between the correlations investigated; between the ones that does not consider surface roughness and that which does, as well as between flow under laminar and turbulent flow conditions

Dampak Bi Rate, Tingkat Suku Bunga, Nilai Tukar, Dan Inflasi Terhadap Nilai Obligasi Pemerintah

The purpose of this study was to examine the influence of BI rate, SBI interest rate, inflation and the exchange rateto value of government bonds in Indonesia Stock Exchange. Data used in this study were secondary data in BIrate, SBI interest rates, inflation and the exchange rate period January 2007 to October 2012. The methods of dataanalysis were multiple regression models and they were analyzed using IBM SPSS software version 20. Theresults showed that partially only the exchange rate that did not significantly influence the value of governmentbonds. This finding could be explained that the exchange rate had no effect related to central bank intervention(Bank Indonesia) to move the exchange rate at the time of depreciation or appreciation

Isolation of bioflocculant-producing bacteria from Penaeus vannamei ponds for the production of extracellular polymeric substances

Bioflocculants are essential polymers with their flocculating activity depending on the characteristics of the secreted flocculants by bioflocculant-producing bacteria. However, the characteristics of bioflocculant produced by microorganisms were not investigated profoundly. In order to better understand these characteristics, determination of extracellular polymeric substances (EPS) from bioflocculant-producing bacteria were characterized in terms of protein concentrations. A total of 51 bioflocculant-producing bacteria isolates were screened from Pacific whiteleg shrimp, Penaeus vannamei culture ponds in Setiu, Terengganu, Malaysia. Screening of bioflocculant-producing bacteria were conducted through morphological approaches followed by protein extraction using Lowry assay method. The identified bioflocculant-producing bacteria includes Corynebacterium sp., Klebsiella sp., Lactobacillus sp., Staphylococcus sp., Bacillus sp., Streptococcus sp., Vibrio spp., Neisseria sp., Serratia sp. and Yersinia sp., with the highest protein concentration of 829 mg mL-1 were attained by Staphylococcus sp. The various amounts of EPS concentration produced by different species of bacteria were dependent on their specific population growth and growth rate. Therefore, the establishment of bioflocculant-producing bacteria isolated from biofloc which showed high tendency for EPS production were performed successfully

Penggunaan Negosiasi Makna dalam Wacana Lisan Guru dan Pengaruhnya terhadap Pemahaman Siswa Kelas IV Sekolah Dasar

This study aimed to describe the shape and type of negotiation of meaning and the frequency of the use of negotiation of meaning that teachers do in their lessons in the fourth grade. Moreover, it also aims to determine the effect of negotiation of meaning to the understanding of fourth grade students. This type of research is descriptive, because it describes the phenomena deslriptif shape and function of the use of negotiation of meaning as it is. The instrument used in this study are guidelines for observation, interview and test. The main instrument in this study is the researchers themselves who aided and supported by the other instruments. In the qualitative method, using observation sheet instruments and guidelines for the interview. Researchers used data collection techniques such as observation sheets, interview and test. The results showed that There are nine forms of negotiation of meaning. The form of negotiations that meaning is, ask questions inducement, explain, repeat, evaluating, defining, affirmation, outlines, and respond. There are nine functions Function negotiation negotiation of meaning that meaning is, requests for clarification, confirmation, confirmation check, repair or correction of its own, expansion, demand explanations, clarifications reply, reply confirmation, and reply as an answer. Frequency negotiation of meaning that most often appears on learning is a check confirmation. more often negotiate meaning it appears, increasing student understanding.Penelitian ini bertujuan untuk mendeskripsikan bentuk dan jenis negosiasi makna dan frekuensi penggunaan negosiasi makna yang dilakukan guru dalam pembelajaran yang dilakukan di kelas IV SD. Selain itu, untuk mengetahui pengaruh negosiasi makna terhadap pemahaman siswa kelas IV SD. Jenis penelitian ini adalah deskriptif karena memaparkan fenomena bentuk dan fungsi penggunaan negosiasi makna secara apa adanya. Instrumen yang digunakan dalam penelitian ini adalah pedoman observasi, pedoman wawancara, dan tes. Instrumen utama dalam penelitian ini adalah peneliti sendiri yang dibantu dan didukung oleh instrumen lainnya. Pada metode kualitatif, menggunakan instrumen lembar observasi dan pedoman wawancara. Peneliti menggunakan teknik pengumpulan data berupa lembar observasi, pedoman wawancara, dan tes. Hasil penelitian menunjukkan bahwa terdapat sembilan bentuk negosiasi makna. Bentuk negosiasi makna tersebut adalah, bertanya, pertanyaan pancingan, menjelaskan, mengulang, melakukan evaluasi, mendefinisikan, penegasan, menguraikan, dan menanggapi. Terdapat sembilan fungsi negosiasi makna, yaitu permintaan klarifikasi, konfirmasi, cek konfirmasi, perbaikan atau dikoreksi sendiri, perluasan, permintaan penjelasan, membalas klarifikasi, membalas konfirmasi, dan membalas sebagai jawaban. Frekuensi negosiasi makna yang paling sering muncul pada pembelajaran adalah cek konfirmasi. semakin sering negosiasi makna itu muncul, pemahaman siswa semakin meningkat

Color Thresholding Techniques Performance for Night Vision Surveillance Using Thermal Imaging

Visible surveillance is commonly an active research worldwide. The need of surveillance allows thermal imaging to participate in this study activity. The drawback of visible surveillance for night monitoring is overcome by the technology of the thermal imaging. To achieve the goal of the surveillance system , the works on detection must be very efficient to do the detection Throughout this research , we developed an algorithm involving thresholding technique for subject detection using thermal image to find the for night surveillance system

Separation of fatty acids from palm oil using organic solvent nanofiltration Pemisahan asid lemak daripada minyak kelapa sawit menggunakan penuras nano pelarut organik

Distillation of fatty acid from traditional recovery method consumes a lot of energy. Membrane process is more preferred because it reduces energy consumption. In this work, the possibility of separating free fatty acid (FFA) from palm oil using organic solvent nanofiltration was studied. Various commercial organic solvent nanofiltration membranes were tested using dead end filtration for their ability to remove free fatty acid from palm oil/acetone mixture. In all membranes, triglycerides (TAG) were preferentially retained at increasing pressure, while FFA were permeated through the membrane. All the three membranes showed selective permeation of FFA, with Solsep 030306 gave the highest selectivity of FFA over triglycerides. The best fatty acid separation performance was achieved using NF030306 membrane with acetone at pressure in the range of 30 to 40 bar and 3.6 g/L concentration of fatty acid. Using NF030306 membrane, 55% of low fatty acid and 87% of triglycerides were rejected from the system. Good separation was achieved at high pressure and concentration. We successfully demonstrated the separation of fatty acid separation from palm oil using organic solvent nanofiltration could be achieved

The effect of the rheocast process on the microstructure and mechanical properties of Al-5.7Si-2Cu-0.3Mg alloy

This study shows the results of an experimental investigation of semisolid rheocasting of Al-5.7Si-2Cu-0.3Mg alloy using a cooling slope (CS) casting technique. However, the challenge is to determine process parameters of the CS process to get a desirable microstructure in the semisolid feedstock material. cooling slope technique was employed to create feedstock material for thixoforming under an argon gas atmosphere, where on an inclined plate that was fixed at a 60° slope angle, molten alloy is poured at different temperatures of 640°C, 650°C and 660°C at lengths 300, 400 and 500 mm. Examination the microstructure with optical microscope observed that the microstructure of conventionally cast alloy presented coarse and dendritic primary α-Al phase, whereas rheocast alloy included fine and nondendritic primary α-Al phase with homogeneous distribution of eutectic phase. The best CS processing condition has been identified for optimum pouring temperature of 650°C and the slope length of 400 mm as average globular grain size of around 31.67 ± 3 μm and a shape factor of about 0.66 ± 0.09 were obtained. The mechanical properties of conventional cast alloy were enhanced by the CS casting process. The ultimate tensile strength, the yield strength and elongation of the rheocast alloy were increased by 10%, 12% and 22% respectively compared to the conventional cast alloy. due to a reduction in shrinkage and porosity of the microstructure of the CS alloy

Detection Technique of Squamous Epithelial Cells in Sputum Slide Images Using Image Processing Analysis

A good quality sputum is important to detect diseases. The presence of squamous epithelial cells (SEC) in sputum slide images is important to determine the quality of sputum. The presence of overlapping SEC in sputum slide images causes the process become complicated and tedious. Therefore this paper discusses on technique of detection and summation for Squamous Epithelial Cell (SEC) in sputum slide image. We addressed the detection problem by combining K-means and color thresholding algorithm. The design of aided system is evaluated using 200 images and the proposed technique is capable to detect and count each SEC from overlapping SEC image. Total of 200 images were clustered to 10 groups, labelled as Group Cell 1 to group Cell 10 that correspond to the number of cells in the image. Therefore, each group will contain 20 images. The accuracy of the algorithm to detect SEC was also measured, and results show that in 91% which provides a correct SEC detection and summation