Sri Suryaningsih

Combustion quality analysis of briquettes from variety of agricultural waste as source of alternative fuels

The increasing in world population and the industrial sector led to increased demand for energy sources. To do this by utilizing the agricultural waste as a fuel source of alternative energy in the form of bio briquette. The aim at this study was to obtain data onto the characteristics of a wide variety of biomass briquettes from waste agricultural industry. The basic ingredients used are biomass waste from coconut husks, sawdust, rice husks and coffee husks. Each of these biomass residues are dried, crushed, then mixed with starch adhesives. This mixture is molded and dried using sunlight. Each type of briquettes was characterized and analyzed the physical-chemical properties, including calorific value, water content, fixed carbon content and the results were compared with charcoal and coal that was used as fuel in public. The results showed that bio briquettes from coconut husks get the highest calorific value of 4,451 cal/g.

Fabrication and characterization of rice husk and coconut shell charcoal based bio-briquettes as alternative energy source

Rice husk and coconut shell have been disposed or burned as waste. As biomass, both of materials are the potential sources of carbon which can be utilized as alternative energy sources. The energy content can be exploited more intensively when packaged in a brief and convenient. In this work, the mixtures of rice husks and coconut shells charcoal were prepared as briquettes. After going through the carbonization process, several measurements have been taken to find out the factors that determine the value of heat energy contains by each component of the charcoals. The basic ingredients briquettes prepared from rice husk and coconut shell charcoal with varying composition and addition of tapioca starch gradually as adhesive material to obtain briquettes in solid with the maximum heat energy content. After going through pressing and drying process, the briquettes with 50:50 percent of composition and the 6% addition of adhesive was found has the highest heat energy content, equal to 4966 cal/g.

ALAT PENDETEKSI dan PENGUKUR KADAR RHODAMIN B SEBAGAI PEWARNA BERBAHAYA PADA MAKANAN dengan BASIS LED RGB

Abstrak Rhodamin B adalah salah satu zat pewarna sintetis yang biasa digunakan pada industri tekstil dan kertas. Zat tersebut ditetapkan sebagai zat yang dilarang penggunaannya pada makanan melalui Menteri Kesehatan (Permenkes) No.239/Menkes/Per/V/85. Namun penggunaan Rhodamin B dalam makanan masih banyak dilakukan oleh masyarakat. Rhodamin B memiliki senyawa pengalkilasi (CH 3 -CH 3 ) yang bersifat radikal sehingga dapat berikatan dengan protein, lemak, dan DNA dalam tubuh. Konsumsi Rhodamin B dalam jangka panjang dapat terakumulasi di dalam tubuh dan dapat menyebabkan gejala pembesaran hati dan ginjal, gangguan fungsi hati, kerusakan hati, gangguan fisiologis tubuh, dan dapat memicu timbulnya kanker hati. Pada penelitian ini telah dilakukan pembuatan alat pendeteksi Rhodamin B yang fleksibel dan mudah dioperasikan dengan basis LED RGB. Berdasarkan hasil eksperimen, senyawa Rhodamin B sangat sensintif terhadap berkas cahaya hijau. Berkas cahaya pada panjang gelombang tersebut mengalami serapan yang cukup tinggi dan berbanding lurus terhadap besarnya kadar Rhodamin B. Alat yang dirancang telah dapat menunjukkan kemampuan untuk membedakan senyawa yang mengandung pewarna Rhodamin B atau tidak. Selain itu alat tersebut juga mampu menghitung perkiraan kadar Rhodamin B dalam satuan mol/liter. Persamaan konversi perubahan tegangan sensor dengan konsentrasi Rhodamin B adalah: konsentrasi (mg/mL) = (tegangan sensor (mV) – 120,98) / (-1,967). Kata-kata kunci: Rhodamin B, LED RGB, pewarna sintetik. Abstract Rhodamine B is a synthetic dye used in the textile and paper industries. These substances are defined as prohibited substances in food through the Minister of Health 239/Menkes/Per/V/85. However, the Rhodamine B is commonly used in the foods by some people. Rhodamine B has an alkylating compounds (CH 3 -CH 3 ) that are radially with binding proteins, fats and DNA in the body. Consumption of Rhodamine B in the long term can accumulate in the body and cause symptoms of an enlarged liver or kidney, impaired liver function, liver damage, physiological disorders of the body, and lead to liver cancer. In this research has been carried out the manufacture of the detector Rhodamine B which flexible and easy to operate on the basis of the RGB LEDs. Based on our experimental results, the Rhodamine B is very sensintif with the green light beam. Beam of light at these wavelengths is absorp by Rhodamin B which proportional to its concentration. Our equipment is designed to demonstrate the ability of distinguish between containing dye Rhodamine B or not. In addition, the equipment is able to calculate the concentration of Rhodamine B in mol / liter. The conversion equation of voltage to concentration of Rhodamine B is: concentration (mg/mL) = (voltage-sensor (mV) – 120,98) / (- 1,967). Keywords : Rhodamin B, RGB LED, synthetic dye .

Influence of wind and topography on distribution of H2S concentration at Cirata hydropower plant and its impact on corrosion rate

Emission of hydrogen sulfide (H2S) gas by diffusion and by bubbling into the atmosphere at tailrace of Cirata hydropower plant give an environmental impact on surrounding area, especially on corrosion of metal surfaces. Field study shows that the highest H2S concentration and the highest corrosion rate are located at the location of Tailrace, with an average concentration of 152.63x10-3 µg.m-3, and corrosion rate of 0.5010 mm.yr-1. Computational Fluid Dynamics is used to develop a simulation model that replicates the function of wind in the distribution of H2S concentration over the complex three dimensional terrain. Results from this simulation are presented and compared with field study data to determine its impact on corrosion rate.

Development of the flow model to determine the placement of the vertical axis wind turbine (VAWT) in the Padjadjaran University area

The wind in urban areas is turbulent and fast changes in direction and velocity. The recent studies indicate that Vertical Axis Wind Turbine (VAWT) is suitable to install in urban areas, especially for small scale VAWT application. The main purpose of this study is to predict the best possible placement of VAWT in the built environment, in case of Padjadjaran University area which is located in an urban area. This study was utilized with Computational Fluid Dynamics to create flow model in wind resource assessment. The geometry model was combined between the natural land form of terrain and man-made environment. Wind direction was predominantly from east and west almost the year at average wind speed 3.9 m/s. This works presented two main possible locations in the placement of the VAWT, in the near ground surface where obstacles created the wind strengthening effect and in the rooftop where an array of obstacles that closely and co-linier with wind direction which was the first obstacle basically blocked ...

Optimal design of an atmospheric water generator (AWG) based on thermo-electric cooler (TEC) for drought in rural area

Drinking water availability is a major issue in some rural area in Indonesia during the summer season due to lack of rainfall, which peoples in this area have to fetch the water a few kilometers away from home. The Atmospheric Water Generator (AWG) is one of the alternative solution for fresh water recovery from atmosphere which is directly condensed the moisture content of water vapor from the air. This paper presents the method to develop a prototype of an AWG based on Thermo-electric cooler (TEC) that used 12 Volt DC, hence its suitability for using renewable energy resource. Computational Fluid Dynamics (CFD) is utilized to optimize the design process in the flow region only, it’s not suitable for recent CFD software to use in Multi physics, because inaccuracy, cost and time saving. Some parameters such as temperature, moisture content, air flow, pressure, form of air flow channel and the water productivity per unit input of energy are to be considered. The result is presented as an experimental proto...