PENGHEMAT BAHAN BAKAR PADA KOMPOR GAS RUMAH TANGGA

A gas saver for gas cooking stove has been investigated, designed, and tested in this work. The device is a conical vertical cylinder placed around the cooking pan. The application of the device does not need any modification of the cooking stove nor the cooking pan. The temperature distribution of hot gas around the cooking pan is computed by means of numerical method. It is found that a significant fuel saving can be obtained using the gas saver because the vertical wall becomes an energy input area to the cooking pan which is not the case in absence of the gas saver. The tests of gas saver have been carried out using aluminum cooking pans of 16 cm and 29 cm diameters to heat 1.30 kg and 2.35 kg of water, respectively. In this preliminary test the gas saver is made of aluminum laminated cartoon. It is found that the gas saver reduces the cooking time and reduces the fuel consumption about 9 "“ 11 %. With the assumption of LPG consumption 12 kg/stove/ month,, 6,000,000 cooking stove used (government plan) and 10% of fuel saving, 86,400,000 kg of LPG will be saved per year. With the price of a gas saver Rp 20,000.00/piece/year, the total money saved will be amounted to Rp 240,000,000.00 per year

PENGEMBANGAN METODE SIMULASI SISTEM PENGKONDISIAN UDARA ENERGI SURYA

In this research, a simulation method has been developed for designing a solar air conditioner and predicting its perfomances. This simulation based on solar irradiation data, solar collector performance data, LiBr-H2O absorption chiller single effect performance data, Phase Change Material (PCM) data as its inputs. Napthalene is used for HTTS and acetic acid is used for TTS. Energy balance, mass balance, and characteristic equations of each component are used in the solar air conditioning simulation. Validation of the developed simulation model was done with experiment data for solar air conditioning system with HTTS and LTTS without auxiliary heater. Generally, the tendency of the simulation and experiment results are similar. The application of HTTS and LTTS make the system can be operated more in 100 minutes

Metodologi Perhitungan Koefisien Perpindahan Panas Konveksi Paksa Fluida Organik Propana pada Kondisi Superkritik

Penelitian tentang siklus Rankine organik superkritis mulai giat dilakukan sebagai salah satu usaha untuk meningkatkan efisiensi termal dari siklus Rankine organik. Pada kondisi superkritik, sifat-sifat termodinamika dan fisika dari fluida organik berubah dengan sangat drastis disekitar titik kritisnya. Sehingga perhitungan koefisien perpindahan panas konveksi paksa tidak dapat lagi dilakukan dengan asumsi sifat-sifat fluida konstan. Dalam penelitian ini diusulkan sebuah metodologi untuk menghitung nilai koefisien perpindahan panas pada kondisi superkritis. Propana digunakan sebagai fluida organiknya. Tipe alat pemindah panas yang dipakai adalah jenis pipa ganda aliran berlawanan arah dan perhitungan bilangan Nusselt menggunakan korelasi Dittus-Boetler dan Gnielinski. Hasil perhitungan koefisien perpindahan panas dengan menggunakan metodologi ini dapat digunakan untuk menghitung luas daerah perpindahan panas dari alat pemindah panas tipe double pipe counter flow. Selanjutnya hasil perhitungan ini perlu dibandingkan dengan nilai koefisien perpindahan panas yang diperoleh dari hasil eksperimen

Evaluation of cardiac energetics by non-invasive \u3csup\u3e31\u3c/sup\u3eP magnetic resonance spectroscopy

\u3cp\u3eAlterations in myocardial energy metabolism have been implicated in the pathophysiology of cardiac diseases such as heart failure and diabetic cardiomyopathy. \u3csup\u3e31\u3c/sup\u3eP magnetic resonance spectroscopy (MRS) is a powerful tool to investigate cardiac energetics non-invasively in vivo, by detecting phosphorus ( \u3csup\u3e31\u3c/sup\u3eP)-containing metabolites involved in energy supply and buffering. In this article, we review the historical development of cardiac \u3csup\u3e31\u3c/sup\u3eP MRS, the readouts used to assess cardiac energetics from \u3csup\u3e31\u3c/sup\u3eP MRS, and how \u3csup\u3e31\u3c/sup\u3eP MRS studies have contributed to the understanding of cardiac energy metabolism in heart failure and diabetes. This article is part of a Special issue entitled Cardiac adaptations to obesity, diabetes and insulin resistance, edited by Professors Jan F.C. Glatz, Jason R.B. Dyck and Christine Des Rosiers. \u3c/p\u3