Chemical and physical properties of Rice Husk as a potential energy resource were analyzed by means Fourier transform infrared (FTIR), x-ray diffraction (XRD), scanning electron microscope (SEM), and energy disperse spectroscopy (EDS). Rice husk is heated with varied temperature of 250˚C, 350˚C, 450˚C and 30, 60, 90 minutes respectively combine with time variation. The results show that the calorific value decreases whenever the temperature and time increase. The heating time of 30 minutes at 250˚C of temperature gives calorific value of 10.4 MJ/Kg. While at the 450˚C of temperature, the calorific value decrease to 4.7 MJ/Kg. The EDS shows that the time of heating is an important parameter where carbon and nitrogen were decreasing with the increment of the heating time while the oxygen increase when the heating time increase. The XRD shows that the broad (002) reflections between 20 o and 30 o indicate carbon disordered with small domains of coherent and parallel stacking of the graphene sheets, which consists of surface morphology from SEM. FTIR shows that the O-H stretching pronounced at around 3452 cm -1 and 3412 cm -1 and pronounced clearly at the highest temperature. The aromatic group from lignin gives rise to C=C asymmetric stretching at cm -1 as a G band corresponds to the sp2-hybradization bonding of carbon atoms and C-H bending modes at 2927 at 796 cm -1 . This results of the characteristic of chemical and physical properties of the rice husk examination provide the prominent source of useful energy that can eventually replace the fossil fuel.

The calculation of mass transfer is one of the key problems in the design of liquid-liquid extractors. Mass transfer between drops and the continuous phase has been studied quite extensively. and a number of models has been developed. Kronig and Brink (1950) derived a theoretical solution to calculate the mass transfer from circulating droplets based on the flow patterns of the creeping flow regime (Re < 1). However, cxperimental results often exceed that predicted by Kronig and Brink (Skelland and Wellek, 1964; Brounshtein ct al., 1970). Other theoretical investigations were carried out numerically by Brounshtein et al. (1970) and Brauer (1979). Their results for the case of predominant resistance to mass transfer inside the droplet are close to that of Kronig and Brink. To improve the agreement between the theoretical formulation and experimental result, some authors (Handlos and Baron, 1957; Steiner, 1986; Temos et al., 1996; Henschke and Pfennig, 1999) applied extended mass-transfer models possessing a special type of turbulent circulation in the droplet. However, of course, these models contradict the fact that due to all observations internal circulation in the droplet is laminar. Furthermore, most theoretical investigations on this subject (Kronig and Brink, 1950; Handlos and Baron, 1957; Brauer. 1979) were carried out for the limiting case of a transfer controlling resistance solely inside the droplet (internal problem). Actually, in liquid-liquid extraction the resistance to mass transfer in the continuous phase cannot be neglected (conjugate problem).To overcome the above mentioned problems, a model formulation and solution method will be presented in this article, which can be used to calculate the concentration fields inside and outsidc of the droplet numerically without the assumption of turbulence inside the droplet. Theoretical Formulation and MethodWe consider the case of a spherical droplet moving in an infinite volume of another liquid with a soluble substance in both phases. The basic assumptions are:The droplet's shape and volume remain constant. Both fluids are Newtonian and incompressible. During mass transfer, the physical properties of the droplet and of the continuous phase are constant and interfacial mass transfer occurs only for the solute.The flow fields inside and outside of the droplet are steady and axisymmetric.There are no surface-active contaminants. In this case the equation of motion for both phases may be written as follows:and the continuity equation reads where the subscript i is equal 1 for the droplet and 2 for the continuous phase.The boundary conditions related to this problem in spherical coordinates ( 0 -polar angle coordinate; r -radial coordinate) are:At the droplet interface

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Biochars from bamboo leaves as a potential energy resource were synthesized by annealing in the oxygen-free environment. Samples were characterized using proximate analysis, Fourier-transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). Heating temperatures are 250°C, 300°C, and 350°C and for each temperature, the time was varied between 30, 60, and 90 minutes. The heating time for 30 minutes results in FC 30.777% and calorific value 15 MJ/Kg at temperature 250°C and decreased to 4.004% and 6 MJ/Kg at temperature 350°C, respectively. EDS shows the time of heating is an important parameter which shows the carbon and nitrogen contents were decreasing with the increase in the heating time, and silicon and oxygen contents were increasing with increase in the heating time. XRD shows broad (002) reflections between 20° and 30°, which indicated disordered carbon with small domains of coherent and parallel stacking of the graphene sheets, which is consistent with surface morphology of the SEM image. The experimental results indicated that heating at 300°C for 30 minutes is an effective and efficient parameter for fabrication of low-cost carbon from bamboo leaves which is a source of useful energy.

The characterization of a spectrum splitter of both hot and cold mirror, type TechSpec AOI 50.0, using a 50-Watt halogen bulb light has been done. Both the bulb spectrum, prior to and after spectrum splitting, are described in this study to see the degradation of radiation that occurs because partial energy is absorbed by the splitter. This characterization plays an important role in determining the best position of a photovoltaic (PV) and thermoelectric generator (TEG) in a PV-TEG system. The light spectrum was recorded using mini USB spectrometer hardware and Spectragryph version 1.2.8 software as optical spectroscopic software that displays light records coming with wavelength (nm) on the x-axis and light spectrum intensity in arbitrary units (a.u.) on the y-axis. The measurement results show that the light intensity in the visible light region (300–750) nm is more dominant than the intensity in infrared light (>750 nm), so that the PV placement is preferred over TEG. Furthermore, with a cold mirror, PV is more suitable if placed in a position to receive reflected light, while using a hot mirror is more suitable in the position transmitted light. For TEG, it is placed in a position opposite to PV. As a result, the maximum intensity of the PV light spectrum with cold mirrors is 46.52 a.u at a wavelength of 479.6 nm, while with hot mirrors it is 42.07 a.u with a 457.6 nm wavelength. It can be concluded that the value of the light intensity with a cold mirror is better than that with a hot mirror on the visible light (Vis) spectrum, and the current and voltage are equivalent to the results of the radiation energy area. It was proven that the maximum total output of a hybrid PV-TEG system with Cold Mirror is greater than that with Hot Mirror (100.53 > 68.77) × 10−3 µW. Based on the result of this study, it is recommended that further research can be conducted to increase radiation energy and output power in TEG.

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Abstract-To increase agricultural output it is needed a system that can help the environmental conditions for optimum plant growth. Smart greenhouse allows for plants to grow optimally, because the temperature and humidity can be controlled so that no drastic changes. It is necessary for optimal smart greenhouse needed a system to manipulate the environment in accordance with the needs of the plant. In this case the setting temperature and humidity in the greenhouse according to the needs of the plant. So using an automated system for keeping such environmental condition is important. In this study, the authors use fuzzy logic to make the duration of watering the plants more dynamic in accordance with the input temperature and humidity so that the temperature and humidity in the green house plants maintained in accordance to the reference condition. Based on the experimental results using fuzzy logic method is effective to control the duration of watering and to maintain the optimum temperature and humidity inside the greenhouse

The experimental stages of converting solar energy into electrical energy in Photovoltaic and Thermoelectric Generator (PV-TEG) hybird ​​takes a long time. Modeling is one approach to find out the initial data before conducting experiments leading to minimize design errors, time and budget. A mathematical model is created to analyze the performance of a PV-TEG hybrid module. Modeling is performed as an electrical circuit equivalent to Kirchoff's Curent Law (KCL) by deriving several equations corresponding to the characteristics of each module. Type of PV is amorphous Silicon (a-Si), while TEG is Bismuth Telluride (Bi2Te3). The AM1.5D standard solar spectrum is splitted its wavelength spectrum using hot mirror, where the wavelengths of 400-690 nm are transmitted to PV and 690-1150 nm are reflected to TEG. All of PV-TEG hybrid parameters, for example intensity, temperature, and material property are obtained from the specification data of each module. As a results, the maximum total power is 0.0437 W with 5.1% its efficiency.