Pemanfaatan Energi Gas Buang Motor Diesel Stasioner Untuk Pemanas Air

Exhaust gas from a diesel engine is having a big deal of energy. In a stationer diesel engine, the enthalpy of water will be increased by flowing the water in a spiral pipe which is located in the exhaust manifold of the engine. Using copper pipes in this heat exchanger, it's efficiency is found up to 69,5 %

Pengaruh Naphtalene Terhadap Perubahan Angka Oktan Bensin Unjuk Kerja Motor Dan Gas Buangnya

Octane number is a reference to measure quality of gasoline as the fuel of gasoline engine. Gasoline with higher octane number gives less tendency to knocking. Naphtalene is a chemical solution that gives positive effect to rise the octane number. Octane number of gasoline can be measured by CFR engine. Using a motor Daihatsu CB-23, the best power obtained by using a grain of naphtalene (3,75 grams) for 3 litres of gasoline and ignition timing is 12° before TDC. Using this ratio, CO & CO2 that are produced in the exhaust gas is nearly the ame with pure gasoline usge but less HC and O2 are produced

Effectiveness of Indonesian Essential Oil Mixture of Lemongrass, Cananga, and Patchouli in Relaxation Through Inhalation: a Clinical Test on Healthy Woman with High Potential for Stress

Relaxation is one of many mechanisms for coping with stress. One of the most widely used methods for relaxation is aromatherapy with the application of essential oils. Known for their therapeutic benefits, essential oils can be extracted from various Indonesian native herbs such as lemongrass (sereh wangi or Cymbopogon winterianus), cananga or ylang-ylang (kenanga or Canarium odoratum), and patchouli (nilam or Pogostemon cabin). This study aims to examine the effectiveness of a mixture of Indonesian essential oil made of lemongrass, cananga, and patchouli extracts. Experiment was conducted by asking a number of subjects to inhale the oil mixture and assessing its effectiveness in terms of psychological relaxation by using Visual Analog Scale or VAS) and of physical relaxation by examining the subjects’ blood pressure (MAP), pulse frequency, and breathing frequency. The result was then compared with that of lavender oil and with the control group. The study was conducted on 60 healthy women through single-blind clinical trials (before and after) using the “intent to treat” approach, followed by a startle test. Participants were divided into three groups: (1) 20 participants who were treated with Indonesian essential oil mixture, (2) 20 participants who were treated with lavender oil, and (3) 20 participants who served as the control group. Psychological relaxation measurement showed that Indonesian essential oil mixture produced the same degree of effectiveness as lavender oil and the control groups did, although both treatments tended to produce better results than the control group did. However, physical relaxation measurement showed that Indonesian essential oil mixture produced a higher degree of effectiveness than lavender oil and tended to produce a better result than the control group did, especially in terms of blood pressure based on MAP scores.    &nbsp

Pemanfaatan Citra Satelit Aster Vnir Untuk Penyusunan Peta Kerentanan Banjir Di Daerah Aliran Sungai Gung Tegal Jawa Tengah

Penelitian ini bertujuan untuk (1) Mengetahui kemampuan citra ASTER VNIR untuk menyusun petakerentanan banjir berdasarkan parameter fisik lahan DAS Gung Tegal. (2) Mengetahui distribusi daerah yangrentan terhadap banjir di Daerah Aliran Sungai Gung, Tegal, Jawa Tengah. Metode yang digunakan adalahmetode Cook melalui pendekatan parameter fisik lahan. Hasil penyadapan citra penginderaan jauh digunakanuntuk menghitung koefisien limpasan permukaan dan debit puncak banjir dengan metode rasional. Hasilpenelitian menunjukkan bahwa citra ASTER yang diintegrasikan dengan Sistem Informasi Geografis mampumenyadap parameter fisik lahan untuk kerentanan banjir. Hasil uji ketelitian perhitungan debit puncak banjirmenggunakan metode Cook dengan data AWLR adalah 73,58% sedangkan dengan pengukuran kapasitastampung sungai metode Manning sebesar 89%. Distribusi wilayah yang rentan tergenang banjir seluas5.262.235 m² yang mencakup Kecamatan Kramat, Tegal Timur, Tegal Barat dan Tegal Selatan

The Impact of Macroeconomic Variables on the Fluctuation of Jakarta Composite Index (Jci) in Indonesia Stock Exchange (Study at Indonesia Stock Exchange for the Period of 2003-2012)

The purpose of this paper is to analyze the impact of macroeconomic variables on the fluctuation of Jakarta Composite Index (JCI) in Indonesia Stock Exchange. This research consists of four macroeconomic variables as independent variables; inflation, BI rate, exchange rate of rupiah against U.S. dollar and real GDP. The using of JCI as dependent variable is because of it reflects the price change in different types of stocks in the Indonesia capital market as generally. Ordinary Least Square (OLS) is used as data analysis technique. Quarterly data are obtained for the period of ten years starting from January 2003 until December 2012. Augmented Dickey Fuller (ADF) and Phillips-Perron (PP) Unit Root test is employed to check the stationary of data. The results show that data has autocorrelation problem, therefore modifying original equation is taken to take account of the serial correlation by transforming all the variables by r differencing using first differences (regressing yt – yt-1 and xt – xt-1). The result reveals that macroeconomic variables simultaneously have significant impact on JCI. In addition, there are significantly negative impact of BI rate and exchange rate on JCI. The result also reveals that inflation and real GDP do not have any significant impact on JCI

Peningkatan Performance Motor Bensin 4 Tak 3 Silinder Yang Menggunakan Bahan Bakar Gas Dengan Penambahan Blower Dan Sistem Injeksi

Replacing from gasoline to gas fuel (BBG) for automotive, in fact, decreases the motorâs power. By adding some equipments such as blower (+ inverter) and BBG injection, the pressure and density of BBG and air mixture into combustion chamber will be higher. This can make the power of combustion engine be equal even bigger than using gasoline

Peningkatan Unjuk Kerja Motor Diesel Dengan Penambahan Pemanas Solar

The imperfect combustion process will be a problem in the development effort of diesel engine's performance. Nonhomogen air-fuel mixing process is one of the factors which cause the imperfect combustion. By heating up the diesel fuel up to a certain temperature before it goes through the high pressure injection pump will lower its density and viscosity. Therefore, when injected in the combustion chamber, it will formed smaller droplets of fuel spray which result in a more homogenious air-fuel mixture. Also by using higher temperature will make the diesel fuel easier to ignite in order to compensate the limited time which is available in high speed operating conditions. Diesel fuel heating can improve the combustion process to increase the power and decrease the fuel consumption optimally