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"Failure of flow a fluid from a equipment to other equipment often happen caused by significant presure drop. To ascertain pressure ability flow of fluid in piping system necessary done calculation pressure drop earlier in engineering, because pressure drop that calculated to make base generate of pipe routing correctly is connects fron nozzle of vessel to nozzle of suction compressor."

"Penelitian ini bertujuan untuk mengetahui hubungan antara tekanan dan kecepatan pada fluida laminer yang terdapat dalam Persamaan Bernoulli serta mendesain dan membuat rancang bangun pengukuran debit fluida menggunakan metode alat tabung venturi dan orifice plate. Penelitian menggunakan data kuantitatif dengan mengambil data berupa pengukuran tekanan yang terjadi pada alat tabung venturi dan orifice plate. Sensor MPXV7002DP digunakan dalam penelitian sebagai alat ukur perbedaan tekanan yang mengeluarkan data analog sehingga harus diolah terlebih dahulu menjadi data tekanan dengan menanamkan fungsi transfer ke dalam Mikrokontroler ATmega8 sebagai media akuisisi data yang diberikan oleh Sensor MPXV7002DP. Data kuantitatif terdiri dari tekanan, debit, dan kecepatan fluida yang berbentuk grafik. Pengolahan dari data tersebut menghasilkan hubungan antara tekanan dan kecepatan yang berupa akar dari ΔP dan nilai massa jenis fluida cair (air) yang digunakan sebesar 1.000,208 kg/m3.

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The main purpose of this research is to observe the relation between pressure and velocity of a laminary fluid using Bernoulli?s formula and to design a prototype of flow measurement device using venturi tube and orifice plate. This research is conducted by gathering quantitative data such as pressure within the venturi tube and the orifice plate. The MPXV7002DP sensor which is used to measure the pressure difference has an analog output so it has to be converted into pressure data using a transfer function embedded in the ATmega8 microcontroller. The quantitative data measured are pressure, flow, fluid velocity, and are visualized using graphs. Data processing yields a relationship between pressure and velocity which is the square root of ΔP and the density of the fluid used (water) was 1.000,208 kg/m3."

"ABSTRAKBackground of the study, materials and methods: Pregnancy-induced hypertension is still an important cause of maternal and fetal morbidity and mortality. Blood pressure changes during pregnancy especially in the second- and third trimester is very important to be monitored properly during prenatal care through routine blood pressure measurement as an early detection for prevention of pregnancy-induced hypertension. Though its etiology is still unknown, based on various epidemiological studies some nutritional- and non- nutritional factors were believed to be its predisposing factors, which also should be considered during prenatal care. A study had been carried out on 45 pregnant women in all 14 RW of Kelurahan Utan Kayu Selatan, Jakarta, Indonesia. They were followed fortnightly for a 6 weeks observational period to see the relationships between magnesium concentration in serum and in erythrocyte, and blood pressures changes in their second- and/or third trimester, and to see also factors that might influence this blood pressure changes. Anthropometrics, clinical, biochemical, and dietary assessments were done to gather data needed for this observational study. The data was analyzed using statistical tests at alpha equal to 0.05 as the significance level. Results and conclusion: Hypertension based on the operational definition of this study was found in 4.4% of the subjects. Blood pressure changes in pregnancy in this study only significantly related to primigravida. The intakes of calorie, protein, saturated fatty acid, sodium and magnesium were found to be significantly different (p < 0.001) compared to its RDA, yet no significant was found with blood pressure changes/hypertension. Magnesium concentration in serum was mostly within the normal range (1.9 - 2.5 mg/dl) in 73.33% of the subjects, while magnesium concentration in erythrocyte was mostly lower than the normal range (5.7 - 7.5 mg/dl) in 73.33 % of the subjects. The concentration of magnesium in erythrocyte was significantly lower (p < 0.001) than the normal level after the 20th week of gestation. The data did not show any significant correlation on the relationship between the concentration of magnesium both in serum and in erythrocyte with blood pressure changes / hypertension."

"Penelitian ini dilakukan untuk melakukan validasi beberapa pressure gauge yang terdapat pada mesin PLTU 450 Watt dengan adanya permasalahan nilai efisiensi termal pada penelitian sebelumnya yang sangat rendah jika dibandingkan dengan nilai efisiensi normal. Adanya dugaan bahwa hasil pengukuran tekanan oleh pressure gauge yang kurang akurat sehingga menjadi salah satu faktor penyebab perhitungan nilai efisiensi yang kecil. Validasi pressure gauge ini dilakukan dengan metode perbandingan dengan suatu pressure transducer merk OMEGA tipe PX800-100 GV yang memiliki tingkat akurasi yang lebih tinggi bila dibandingkan dengan pressure gauge. Dari hasil pengujian pressure transducer, dapat diketahui bahwa output pressure transducer berbanding lurus (linear) dengan tekanan input yang diberikan dan memiliki nilai gradien garis 13,61 milivolt per bar gauge (barg) pada rentang pengukuran 0-8 barg. Dari hasil validasi pressure gauge terhadap 5 pressure gauge pada rentang tekanan 0- 8 barg dapat diketahui bahwa kelima pressure gauge memiliki range nilai akurasi 5% - 7,5%. Dengan demikian jika dibandingkan dengan nilai akurasi sesuai spesifikasinya yaitu 1,5 %, nilai akurasi pressure gauge P-01 s.d. P-05 memiliki nilai akurasi yang sudah turun.

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The study was conducted to validate some pressure gauges located on the 450 watt power plant engine. The calculation of thermal efficiency in the previous studies was very low comparing to the normal efficiency. That was alleged by the pressure measurement which less accurate. Pressure gauge validation was performed by the method of comparison with a pressure transducer OMEGA PX800-100 GV that has higher accuracy when it was compared to the pressure gauge.

From the test results, it could be seen that the pressure transducer output is directly proportional (linear) with a given input pressure and has a gradient of line 13.61 milivolts per bar gauge (barg) in the measurement range of 0-8 barg. Validation results of five pressure gauges in the range of 0-8 barg have 5%-7,5% accuracy. Thus when this actual accuracy were compared with their pressure gauge specification, i.e 1.5%, the accuracy of all pressure gauges has been dropped."

"Kerugin jatuh tekan (presssure drop) mempunyai pengaruh yang sangat penting pada dunia industri. Kerugian jatuh tekan ialah kerugian energi yang dibutuhkan untuk memindahkan fluida. Perancangan alat sangat menentukan pengaruh pada pressure drop, mulai dari pemilihan reducer, valve, tee, elbow, dll. Gesekan-gesekan yang terjadi pada aliran fluida dalam pipa sangat sering terjadi. Koefisien gesek didapat dari tegangan geser yang terjadi diantara setiap perbedaan lapisan kecepatan. Pemilihan pipa PVC Ø 19 mm memungkinkan untuk mengurangi pressure drop yang terjadi. Pipa PVC paling sering digunakan untuk sistem irigasi, dan penyaluran air rumah tangga. Suatu bilangan yang dapat mengidentifikasikan antara suatu aliran lainar atau aliran turbulen ialah bilangan Reynolds. Tujuan dari penelitian yaitu untuk mengetahui hubungan bilangan REynolds terhadap nilai koefisien gesek pada pipa PVC. Dimana semakin tinggi bilangan Reynolds maka nilai koefisien gesek semakin kecil. Mengetahui karakteristik aliran dan distribusi kecepatan yang terjadi pada pipa PVC. Penggunaan tiga buah pressure gauge untuk mengukur perbedaan tekanan antar tab. Untuk pengujian, bahan yang diuji adalah air.

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Pressure drop have a very important influence in the world. Pressure drop is energy loss required to moving of fluid. Design tool will determine the effecr on pressure drop, ranging from selecting the reducer, valve, tee, elbow, etc. Friction-friction that occurs in the fluid flow in pipes are very commonly. The coefficient of friction obtain from shear stress that occurs between each layer of the speed difference. Selection og PVC pipe Ø 19 mm make it possible to reduce the pressure drop occur, The most commonly use PVC pipe for irrigation system and supply household water.

The purpose of this study was to corrleate the Reynolds number on the value of friction coefficient on the PVC pipe. If the Reynolds number to high, so coefficient of friction as be small. Knowing the characteristics of flow and velocity distributions that occur in PVC pipe. Utilizing three pieces of pressure gauge for measure the pressure difference inter pressure tab. For testing, the material tested water."

"Peningkatan kebutuhan akan kemudahan transportasi antar wilayah, memacu pemerintah Indonesia untuk membuat insfrastruktur transportasi yang lebih baik. Untuk itu, dibuatlah proyek Kereta Cepat Jakarta-Bandung. Proyek ini menggunakan model kereta Fuxing CR400AF yang memiliki kecepatan operasional hingga 350 km/jam. Pada kecepatan tersebut, muncul masalah-masalah aerodinamik, salah satunya berupa micro-pressure waves. Fenomena tersebut menjadi masalah baru di berbagai negara, karena sangat berkaitan erat dengan peningkatan kecepatan kereta. Semakin tinggi kecepatan operasional kereta, akan meningkatkan nilai micro-pressure waves, yang dapat berdampak buruk bagi kesehatan manusia dan kekuatan konstruksi bangunan di sekitarnya. Pada penelitian ini dilakukan simulasi numerik, berupa CFD, menggunakan perangkat lunak ANSYS FLUENT. Skema pada penelitian adalah kereta melintasi sebuah terowongan, di mana fase awal micro-pressure waves terjadi saat kereta masuk terowongan. Fokus penelitian ini adalah pengukuran pressure gradient yang nilainya berkorelasi dengan micro-pressure waves. Terdapat 4 variasi tunnel portal, yaitu enlarged tunnel portal, enlarged vent tunnel portal, linear tunnel portal, dan tunnel portal walini, yang akan dibandingkan juga dengan terowongan tanpa tunnel portal. Hasil dari penelitian ini, desain tunnel portal walini memiliki maksimum pressure gradient yang paling rendah, dengan total penurunan 19,4% dibandingkan dengan variasi tanpa tunnel portal. Selain itu, juga diamati dampak perubahan variasi tunnel portal terhadap efek aerodinamik pada kereta. Hasilnya, perbedaan variasi antar tunnel portal tidak menunjukkan perbedaan yang signifikan, tetapi masih jauh menurun apabila dibandingkan dengan variasi tanpa tunnel portal. Variasi terbaik dapat menurunkan tekanan maksimum dan koefisien drag adalah enlarged tunnel vent portal, dengan masing-masing penurunan sebesar 19,7% dan 23,6%.

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The increasing demand for interregional transportation convenience has driven the Indonesian government to establish improved transportation infrastructure, leading to the development of the Jakarta-Bandung High-Speed Train project. This project utilizes the Fuxing CR400AF train model, capable of operating speeds up to 350 km/h. At such velocities, aerodynamic issues arise, including the micro-pressure waves phenomenon. Micro-pressure waves have become a new concern in various countries as it is closely related to the increased speed of trains. The higher the operational speed of the train, the worse the impact of micro-pressure waves on human health and the structural integrity of surrounding buildings. In this study, numerical simulations (CFD) using ANSYS FLUENT software were conducted. The research scenario involved the train passing through a tunnel, where the initial phase of the micro-pressure waves occurred upon the train's entry into the tunnel. The primary focus of this study was to measure the pressure gradient, which correlates with the micro-pressure waves. Four variations of tunnel portals were considered: enlarged tunnel portal, enlarged vent tunnel portal, linear tunnel portal, and walini tunnel portal, all of which were compared to a tunnel without a tunnel portal. The research findings indicate that the walini tunnel portal design exhibited the lowest maximum pressure gradient, with a total decrease of 19.4% compared to the variation without a tunnel portal. Additionally, the study examined the impact of different tunnel portal variations on the aerodynamic effects of the train. The results showed that the variations between tunnel portals did not significantly differ; however, they still exhibited considerable decreases compared to the variation without a tunnel portal. The enlarged vent tunnel portal was the best variation, capable of reducing maximum pressure and drag coefficient, with respective reductions of 19.7% and 23.6%."

"ABSTRAKKetersediaan sumber energi terutama energi fosil semakin lama semakin berkurang. Sehingga, perlu adanya upaya efisiensi energi dengan mengembangkan Turbin Gas Mikro Bioenergi Proto X-3 dimana terdapat sistem turbin gas mikro dengan bahan bakar biogas untuk aplikasi pada zero energi green building. Bahan bakar biogas yang diperoleh dari limbah disimpan pada suatu bejana bertekanan. Penelitian ini dikhususkan pada analisa aliran biogas di dalam bejana bertekanan guna mendapatkan tebal dinding bejana optimal dari variasi perubahan suhu dan perubahan tekanan pada tabung gas. Metode yang digunakan dalam penelitian ini yaitu mensimulasikan aliran di dalam bejana bertekanan selama pengisian bahan bakar. Dari hasil simulasi didapatkan hasil perubahan tekanan selama pengisian adalah 117 Bar - 349 Bar, massa jenis bahan bakar 406.3 Kg/m3 - 689.2 Kg/m3 dan kecepatan bahan bakar selama pengisian 279m/s - 8.3 m/s.

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ABSTRACTAvailability of energy resources, especially fossil energy increasingly reduced. Therefore need energy efficiency efforts by developing Micro Gas Turbines Bioenergy Proto X-3 where there system micro gas turbines with biogas fuel for applications in green building zero energy. Biogas fuel was derived from waste is stored in a pressurized vessel. This research is devoted to the analysis of the biogas stream in the pressure vessel in order to obtain optimal thickness of vessel based on variations of temperature change and pressure change in the gas cylinder. The method used in this research that simulates the flow inside the pressure vessels during refueling. From the simulation results showed changes in pressure during filling is 117 bar - 349 bar, the density of the fuel 406.3 Kg / m3 - 689.2 Kg / m3 and the speed of the fuel during filling 279m / s - 8.3 m / s."