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"Energi merupakan unsur yang selalu berhadapan dengan manusia dalam kehidupan sehari-hari, yang terdiri dari beberapa jenis, seperti energi potensial, energi mekanik, energi kinetik dan lainya. Kalor juga merupakan energi yang sangat dibutuhkan kemampuan untuk memanfaatkan energi ini. Kalor juga memiliki sifat dapat berpindah dari suatu tempat ke tempat lainya, salah satunya adalah radiasi. Radiasi kalor merupakan sumber energi yang sangat baik untuk dimanfaatkan karena sifatnya yang mampu berpindah tanpa adanya perantara. Namun radiasi juga dapat membahayakan jika fluks kalor yang dipaparkan sangat besar yang mampu memicu penyalaan api pada objek yang terpapar.untuk menghindari hal tersebut maka perlu diantisipasi dengan salah satu cara melakukan pemetaan radiasi kalor pada suatu area tersebut. Pemetaan yang dilakukan terdiri dari beberapa faktor seperti jarak, offset, elevasi dan sudut pandang. Tentu saja jika sumber panas berada pada area fluida menyebabkan adanya pengaruh konveksi pada fluks kalor yang terukur. Kalor yang dihasilkan akan mengubah karakteristik udara disekitar objek yang dipaparkan dan akan membentuk sebuah lapisan batas yang memiliki ketebalan sesuai dengan karakteristik aliran kalor.

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Energy is always connected with human life in every day, which is like potential energy, mechanical energy, kinetic energy and others. Heat is also a kind of energy, that rsquo s needed skill and capabilites to use this energy. Heat also has properties that can devolve to others place, one of that is radiation. Heat radiation is a very good energy to be exploited because of the nature characteristics of radiation is being able to move without a medium. However, radiation can also be dangerous if the heat flux is very large which can be triggered ignition fire of the object. To keep those things it is necessary to anticipate, one of them is to make a mapping of radiation in the area. Mapping consists of several factors such as distance, offset, elevation and view factor. Of course, if there is heat in the fluid region it will cause influence of convection in measurable heat flux. The heat produced of the heater will change the properties of air around exposed object and will form a layer that has a thickness according to the heat flow."

"Karakteristik refrigerant natural (Propane) perlu dikaji lebih dalam saat ini, karena penggunaan refrigerant konvensional (sintetis) sudah mulai dibatasi karena tingginya Ozone Depletion Potential (ODP) dan Global warming potential yang berbahaya untuk keberlangsungan ozon dan menaikkan peluang naiknya suhu bumi. Karakteristik yang ditinjau dalam penelitian ini adalah penurunan tekanan dari masing-masing refrigerant yang dilakukan dengan memvariasikan fluks massa dan fluks kalor. Variasi fluks kalor untuk kedua refrigerant pada penelitian ini adalah 0.20 KW/m2 - 0.69 KW/m2. Sementara untuk fluks massa dari kedua refrigerant diatur supaya mendekati nilai yang sama. Hasil yang didapat adalah penurunan tekanan dipengaruhi oleh fluks kalor danfluks massa serta R-290 mempunyai penurunan tekanan lebih rendah dibanding R-22.

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The characteristics of natural refrigerants (Propane) need to be studied more deeply at this time, because the use of conventional (synthetic) refrigerants is starting to be limited due to the high Ozone Depletion Potential (ODP) and Global warming potential which are dangerous for the sustainability of ozone and increase the chance of rising earth temperatures. The characteristic reviewed in this research is the pressure reduction of each refrigerant which is carried out by varying the mass flux and Heat flux. The variation in Heat flux for the two refrigerants in this study was 0.20 KW/m2 - 0.69 KW/m2. Meanwhile, the mass flux of the two refrigerants is adjusted to approach the same value. The results obtained are that the pressure drop is influenced by Heat flux and mass flux and R-290 has a lower pressure drop than R-22. This predicted result is in accordance with research conducted by A.S Pamitran et al (2010) in testing pressure drops for 5 types of refrigerants."

"ABSTRAKCO2 merupakan salah satu gas penyebab utama pemanasan global yang mengakibatkan perubahan iklim dunia sehingga terjadi kekeringan, kebakaran hutan, naiknya muka air laut, meningkatnya intensitas dan periode hujan. Darat, laut dan atmosfer penyerap CO2 alami. Perairan Indonesia berpotensi menyerap CO2 karena produktifitas primer tinggi.Penelitian ini untuk mengetahui variabilitas CO2 dalam menentukanapakah perairan Indonesia sebagai carbon source atau carbon sink dan mengisi kekosongan data CO2. Penelitian pada bulan Februari-Maret 2010 di Selat Sunda dan bulan April 2010 di Barat Sumatera menggunakan K/R Baruna Jaya III. Data pCO2 udara didapatkan dari hasil rata-rata pengamatan bulanan stasiun Global Atmospheric Watch di Kototabang Bukittinggi pada Februari, Maret dan April 2010.CO2 di lihat dari parameter karbon anorganik, derajat keasaman, totalalkalinitas dan tekanan parsial CO2 di lokasi studi bervariasi dengan nilai berbedabeda. Selat Sunda berperan sebagai source karbon dan barat Sumatera berperan sebagai sink karbon. Tekanan parsial CO2 di selat Sunda dan barat Sumatera lebih dipengaruhi oleh parameter pH. Rata-rata flux bersih CO2 di selat Sunda 841.603 mol CO2cm-2hr-1 yang menunjukkan pelepasan CO2 dari laut ke atmosfer terjadidi wilayah ini dan rata-rata flux bersih CO2 di barat Sumatera -945.292 mol CO2cm-2hr-1 yang menunjukkan penyerapan CO2 oleh laut terjadi di wilayah ini.

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ABSTRACTCO2 is one of the main causes of global warming gases which cause global climate change, droughts, forest fire, sea level rise and flooding. Natural CO2 sinks are the Mainland, oceans and atmosphere. Indonesian waters has the potential to absorb CO2 due to high primary productivity.This research is to know the variability of CO2 in determining whether the Indonesian waters as carbon sources or carbon sinks and fill the CO2 data gaps. dan mengisi kekosongan data CO2. Research in February-March 2010 in the Sunda Strait and April 2010 in west Sumatra, using the RV Baruna Jaya III. Air pCO2 data obtained from the average of monthly observations of the Global Atmospheric Watch station in Kototabang Bukittinggi in February, March and April 2010.CO2 gases in view of the inorganic carbon parameters, acidity, alkalinity and total CO2 partial pressure in the study area varies with different values. Sunda Strait have a role carbon source and west Sumatra as carbon sinks. Partial pressure of CO2 in the Sunda Strait and west Sumatra is more influenced by the pH. The average net flux of CO2 in the Sunda strait 841.603 mol CO2cm-2day-1 which shows the release of CO2 from the ocean into the atmosphere occur in thisregion and average net flux of CO2 in the west of Sumatra -945.292 mol CO2cm-2day-1 which shows the absorption of CO2 by the ocean occurs in the region."

"The purpose of this paper was to investigate the performance of ceramic filters made from a mixture of natural clay, rice bran, and iron powder in removing cadmium from pulp industry effluent. Some parameters were examined such as acidity, total dissolved solid (TDS), total suspended solid (TSS), electrical conductivity (EC), and cadmium concentration. Results showed that the composition percentage of the ceramic filter, which in this case amounted to 87.5% natural clay, 10% rice bran, and 2.5% iron powder, may decrease cadmium concentration in pulp industry effluent by up to 99.0%. Furthermore, the permeate flux decreased after 30 minutes of filtration time, and subsequently became constant at one hour of contact time. In addition, Scanning Electron Microscope (SEM) micrographs of the ceramic filter surfaces indicate that ceramic filters have a random pore structure and can be categorized as microfiltration filters."

"Perpindahan panas sudah dipelajari sejak lama karena memiliki manfaat bagi manusia seperti energi matahari. Penggunaan energi matahari adalah salah satu perpindahan panas dengan cara radiasi. Dengan perkembangan teknologi yang semakin berkembang pesat, manusia membuat alat dengan memanfaatkan energi matahari tersebut, seperti Solar Water Heater. Untuk mendapatkan efisiensi termal yang baik, diperlukan sudut kemiringan yang tepat pada pemasangan kolektor SWH. Maka, diperlukan alat untuk mengetahui besar nilai radiasi yang diterima, yaitu Radiometer. Alat ini bertujuan untuk mengetahui besar nilai fluks kalor. Pengujian Alat Radiometer dilakukan dengan variasi jarak sensor terhadap pemanas, faktor pandang sensor terhadap pemanas, sudut kemiringan sensor dan pemanas, dan offset sensor terhadap pemanas. Pengujian juga dilakukan secara ldquo;eksperimental numerik rdquo; menggunakan FDS dengan skala 1:1. Penelitian ini dapat menunjukkan adanya keserupaan trend hasil antara model numerik dan eksperimental.

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Heat transfer has been studied for a long time because it has benefits for humans like solar energy. The use of solar energy is one of the heat transfer by way of radiation. With the rapidly evolving technological developments, humans make tools by utilizing the solar energy, such as Solar Water Heater. To obtain good thermal efficiency, an appropriate slope angle is required in the installation of the SWH collector. Therefore, a tool is needed to know the value of radiation received, that is Radiometer. This tool aims to know the value of flux of heat.

Radiometer Testing is done by varying the distance of the sensor to the heater, the sensor 39 s viewing factor to the heater, the angle of the sensor and heating, and the sensor offset to the heater. The tests were also conducted in numerical experimental using FDS on a 1 1 scale. This research can show the similarity of trend of result between numerical model and experimental."

"Pengecoran merupakan salah satu metode untuk memproses paduan aluminium sehingga menghasilkan produk. Parameter penting yang dapat menentukan kualitas produk hasil pengecoran adalah kemurnian dan sifat mekanis. Dalam proses pengecoran, kelarutan gas hidrogen dan reaktivitas aluminium terhadap atmosfer akan mengalami peningkatan seiring dengan kenaikan temperatur dan dapat mengakibatkan cacat porositas serta inklusi yang akan berpengaruh pada kebersihan produk hasil cor dan menurunkan sifat mekanisnya. Untuk menghindari cacat pengecoran tersebut dapat dilakukan perlakuan dengan penambahan fluks. Pada penelitian dan literature review ini dilakukan studi pengaruh temperatur peleburan aluminium dengan perlakuan penambahan cleaning flux berbasis NaCl-KCl-Na2SiF6. Cleaning flux dibuat dengan variasi komposisi berdasarkan Na2SiF6 sebesar 5wt%, 10wt%, 15wt%, 20wt%. Material yang digunakan dalam literature review adalah paduan Al-Si-Cu dengan variasi temperatur peleburan 700oC, 740oC, 780oC, 790oC. Karakterisasi material dilakukan dengan menggunakan DSC, OM, SEM, perhitungan inklusi, pengukuran kepadatan dan pengujian tarik. Hasil penelitian dan literature review menunjukkan bahwa peningkatan komposisi Na2SiF6 dalam fluks akan menurunkan temperatur dekomposisi fluks dan meningkatkan efisiensi pengangkatan inklusi dalam aluminium cair. Kemurnian dan sifat mekanis tertinggi diperoleh pada temperatur peleburan 740oC.

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Casting is one of methods for processing aluminum alloys to produce aluminum products. Important parameters that can determine the quality of casting products are purity and mechanical properties. In the casting process, the solubility of hydrogen gas and aluminum reactivity to the atmosphere will increase along with rising temperatures and can result in porosity defects and inclusions that will affect the cleanliness of the cast product and decrease its mechanical properties. To avoid casting defects can be treated with the addition of flux. In this research and literature review, a study on the effect of aluminum melting temperature with the addition of NaCl-KCl- Na2SiF6-based cleaning flux was carried out. Cleaning fluxes were made with composition variation based on Na2SiF6 of 5wt%, 10wt%, 15wt%, 20wt%. The material used in the literature review were Al-Si-Cu alloys with melting temperature variation of 700oC, 740oC, 780oC, 790oC. Material characterization was determined using DSC, OM, SEM, inclusion measurement, density measurement and tension testing. The results of the research and literature review show that increasing the composition of Na2SiF6 in flux decreases the flux decomposition temperature and increases the efficiency of removing inclusions in liquid aluminum. The highest purity and mechanical properties are obtained at melting temperature of 740oC."

"e purpose of this paper was to investigate the performance of ceramic filters made from a mixture of natural clay, rice bran, and iron powder in removing cadmium from pulp industry effluent. Some parameters were examined such as acidity, total dissolved solid (TDS), total suspended solid (TSS), electrical conductivity (EC), and cadmium concentration. Results showed that the composition percentage of the ceramic filter, which in this case amounted to 87.5% natural clay, 10% rice bran, and 2.5% iron powder, may decrease cadmium concentration in pulp industry effluent by up to 99.0%. Furthermore, the permeate flux decreased after 30 minutes of filtration time, and subsequently became constant at one hour of contact time. In addition, Scanning Electron Microscope (SEM) micrographs of the ceramic filter surfaces indicate that ceramic filters have a random pore structure and can be categorized as microfiltration filters."

"Pengembangan pemanfaatan energi baru terbarukan dilakukan dalam rangka mengurangi penggunaan energi fosil yang keberadaannya semakin berkurang, harga yang semakin tinggi, dan siklus pemulihannya yang sangat lama. Penggunaan teknologi untuk mendukung pengembangan energi baru terbarukan salah satunya adalah mesin sinkron yang dapat digunakan untuk memanfaatkan energi angin dan air. Mesin sinkron yang banyak digunakan saat ini merupakan mesin fluks radial, namun terdapat titik jenuh dalam pengembangannya. Mesin fluks aksial atau juga disebut mesin tipe cakram, adalah alternatif untuk mesin fluks radial karena bentuknya yang kompak dan kepadatan daya yang tinggi. Mesin fluks aksial dapat dioperasikan sebagai pembangkit listrik skala kecil hingga menengah, disamping itu mesin ini cukup ideal untuk aplikasi dengan kecepatan rendah. Pada skripsi ini, dilakukan rancang bangun generator fluks aksial magnet permanen. Rancangan generator ini terdiri dari rotor ganda dengan dua belas magnet permanen, serta stator tunggal dengan sembilan kumparan. Bahan dasar yang digunakan untuk stator dan rotor adalah bahan Akrilik, sedangkan magnet permanen menggunakan jenis neodymium N52. Jumlah lilitan setiap kumparan yang terdapat pada stator adalah 260 lilitan. Generator fluks aksial magnet permanen dirancang untuk menghasilkan tegangan fasa ke netral sebesar 4,03 Volt pada kecepatan nominal 500 rpm. Berdasarkan hasil pengukuran didapatkan bahwa nilai tegangan fasa ke netral pada kecepatan putar 500 rpm untuk fasa R = 2,934 Volt, S = 2,97 Volt, T = 2,95 Volt.

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The use of renewable energy overtook fossil fuels cause their decrease in existence, increase in price, and a very long recovery cycle. One of the technologies used to support renewable energy is a synchronous machine. This machine can be used to convert wind and water energy. The radial flux machine is the type of Synchronous machine widely used today, but there are some difficulties in improving their performance. Axial flux machine, also called disc-type machine, is an alternative to radial flux machine due to their compact shape and high power density. Axial flux machines can be operated as small to medium-scale power plants and are ideal for low-speed applications. This thesis focused on designing and building a permanent magnet axial flux generator. The generator design consists of a dual rotor with twelve permanent magnets and a single stator with nine coils. The primary material used for the stator and rotor is Acrylic, and neodymium N52 for a permanent magnet. The number of turns in each coil in the stator is 260 turns. The axial flux permanent magnet generator is designed to produce a line-to-neutral voltage of 4.03 Volts at a speed of 500 rpm. Based on the measurement results, the values of the line-to-neutral voltages at a speed of 500 rpm are R = 2.934 Volt, S = 2.97 Volt, T = 2.95 Volt."

"Ramie waste from result of fiber decomposition process of textile industry contains potential high enough cellulose to be utilized for pulp dissolving making...."

"[ABSTRAKMotor BLDC menjadi motor yang sangat banyak digunakan sekarang karena kelebihannya dibandingkan dengan motor lainnya dalam hal efisiensi, kecepatan dan torsi yang lebih baik, serta umur yang cenderung lebih panjang. Banyak dilakukan penelitian untuk meningkatkan kinerja dari motor BLDC. Penelitian ini bertujuan untuk mencari rancangan motor yang paling optimal, dengan membuat rancangan yang divariasikan pada bagian stator. Penelitian ini dilakukan dengan simulasi motor tanpa beban dan dengan beban.Pada penelitian ini dibuat empat variasi bukaan alur yang dilakukan pada simulasi tanpa beban dan berbeban. Variasi yang dilakukan adalah membuat lengkungan pada alur dan memvariasikan ukuran bukaan alur pada stator. Pada penelitian ini didapatkan nilai-nilai flux linkage, Back EMF kemudian diolah untuk mendapat Ke pada keadaan tanpa beban dan torsi ripple pada keadaan berbeban untuk dibandingkan agar dapat mengetahui rancangan mana yang memiliki performa terbaik. Pada penelitian ini ditemukan bahwa dengan rancangan ukuran yang tepat pada bagian bukaan alur di stator dapat mengurangi daerah saturasi, sehingga pada daerah yang terdapat saturasi dapat diminimalisir panas pada bagian daerah stator motor tersebut dan dapat memperkecil nilai torsi ripple hingga persentase sebesar 6.78% dengan rata-rata torsi ripple sebesar 0.583596818 Nm.ABSTRACTBLDC motors which becoming very widely used now because of its advantages compared to other motor in terms of efficiency, speed and better torque and life tend to be longer. Many research to improve the performance of the BLDC motor. This study aims to find the most optimal motor design, to create designs that varied in the stator. This research was conducted by simulating the motor no load and load.In this study is made of four variations of slot opening performed on the no load and load simulation. Variations to do is make the fillets in the slot opening and varying the size of the slot opening in the stator. In this study obtained values of flux linkage, Back EMF and then processed to obtain Ke in the load simulationand torque ripple at the load simulation of each design are compared to determine which designs that have the best performance.This research found that the design of the right size in the slot opening in the stator can reduce the saturation region, so that in the area there is saturation can be minimized heat in the area of the motor stator and can minimize torque ripple value up to a percentage of 6.78% with an average of 0.583596818 Nm of torque ripple.;BLDC motors which becoming very widely used now because of its advantages compared to other motor in terms of efficiency, speed and better torque and life tend to be longer. Many research to improve the performance of the BLDC motor. This study aims to find the most optimal motor design, to create designs that varied in the stator. This research was conducted by simulating the motor no load and load.In this study is made of four variations of slot opening performed on the no load and load simulation. Variations to do is make the fillets in the slot opening and varying the size of the slot opening in the stator. In this study obtained values of flux linkage, Back EMF and then processed to obtain Ke in the load simulationand torque ripple at the load simulation of each design are compared to determine which designs that have the best performance.This research found that the design of the right size in the slot opening in the stator can reduce the saturation region, so that in the area there is saturation can be minimized heat in the area of the motor stator and can minimize torque ripple value up to a percentage of 6.78% with an average of 0.583596818 Nm of torque ripple.;BLDC motors which becoming very widely used now because of its advantages compared to other motor in terms of efficiency, speed and better torque and life tend to be longer. Many research to improve the performance of the BLDC motor. This study aims to find the most optimal motor design, to create designs that varied in the stator. This research was conducted by simulating the motor no load and load.In this study is made of four variations of slot opening performed on the no load and load simulation. Variations to do is make the fillets in the slot opening and varying the size of the slot opening in the stator. In this study obtained values of flux linkage, Back EMF and then processed to obtain Ke in the load simulationand torque ripple at the load simulation of each design are compared to determine which designs that have the best performance.This research found that the design of the right size in the slot opening in the stator can reduce the saturation region, so that in the area there is saturation can be minimized heat in the area of the motor stator and can minimize torque ripple value up to a percentage of 6.78% with an average of 0.583596818 Nm of torque ripple., BLDC motors which becoming very widely used now because of its advantages compared to other motor in terms of efficiency, speed and better torque and life tend to be longer. Many research to improve the performance of the BLDC motor. This study aims to find the most optimal motor design, to create designs that varied in the stator. This research was conducted by simulating the motor no load and load.In this study is made of four variations of slot opening performed on the no load and load simulation. Variations to do is make the fillets in the slot opening and varying the size of the slot opening in the stator. In this study obtained values of flux linkage, Back EMF and then processed to obtain Ke in the load simulationand torque ripple at the load simulation of each design are compared to determine which designs that have the best performance.This research found that the design of the right size in the slot opening in the stator can reduce the saturation region, so that in the area there is saturation can be minimized heat in the area of the motor stator and can minimize torque ripple value up to a percentage of 6.78% with an average of 0.583596818 Nm of torque ripple.]"