• Applied Chemistry for Engineering
• /
• v.4 no.4
• /
• pp.701-708
• /
• 1993

Hydrodemetallation(HDM) of VO-tetraphenylporphyrin(VO-TPP) was studied over $CoMo/{\gamma}-Al_2O_3$ catalyst at emperatures between $300^{\circ}C$ and $400^{\circ}C$, the total pressure between $15{\times}10^5$ and $30{\times}10^5$ Pa and the contact times between 0.008 and 0.020gcat. hr./ml teed. HDM of VO-TPP was inhibited by pyridine because the increase of pyridine concentration(up to 4mole%) caused the decrease of HDM conversion. The reaction rate of VO-TPP was found to be apparently 1st order over $350^{\circ}C$ and its activation energy was determined to be about 23kca1/mo1e by Arrhenius plot. Pore mouth-plugging phenomena were shown by ad/desorption isotherm and pore size distribution of fresh and aged catalysts.

• Applied Chemistry for Engineering
• /
• v.8 no.5
• /
• pp.749-755
• /
• 1997

Molybdenum phosphate(P/Mo = 0.6) has been synthesized with ammonium molybdate and phosphoric acid under aqueous solution. The kinetics of the ammoxidation of methylpyrazine over molybdenum phosphate catalyst was investigated with the variation of reaction temperature and partial pressure of methylpyrazine, oxygen and ammonia, respectively at atmospheric pressure. The catalytic activity was constant for 300hrs operation under our experimental conditions. Under the steady-state condition, the rate equation of methylpyrazine was shown as $-r=kP_{MP}P_{NH3}{^0}P_{O2}{^{\gamma}}({\gamma}=2.2;1.3{\leq}P_{O2}(kPa){\leq}4)$. The apparent activation energy was 29.6kcal/mol below 623K. The main product obtained in the ammoxidation of methylpyrazine is cyanopyrazine whose selectively was kept always over 90% regardless of conversion.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.10 no.4
• /
• pp.86-95
• /
• 2002

Anaerobic digestion of municipal solid waste(MSW) is recently getting attention due to energy generation and abatement of global warming. MSW has high solid content and low nitrogen content. Its major component is cellulose and hemicellulose. The conversion rate of organic portion of MSW to methane is approximately 50%, representing $0.2m^3/kg$ VS. Long hydraulic retention time is required for high solid content and inoculum should be mixed with the feed. When MSW is digested anaerobically, maximum limit of C/N ratio is 25 and the optimum concentration of $NH_3-N$ is 700mg/L. lime and sodium bicarbonate are used to adjust pH. Excess addition of sodium bicarbonate above 3,500mg/L will cause sodium toxicity. Thermophilic anaerobic digestion is effective in the control of pathogen although its operation and maintenance is difficult. To optimize the anaerobic digestion of MSW, it is necessary to understand the mechanism of microorganims involved in anaerobic digestion.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.6
• /
• pp.873-879
• /
• 2003

The study was conducted to improve the nutritive value of defatted rice polishing (DRP). DRP was treated with various concentrations of HCl, NaOH, $H_2O_2$ and Kemzyme-H $F^{(R)} and the effect on its chemical composition and nutritive value in broiler chicks was observed. The treatments levels of 0.4 N HCl, 0.2 N NaOH and 6% $H_2O_2$ were selected from many concentrations of HCl, NaOH and $H_2O_2$ tried earlier on DRP. The selection was made on the basis of release of nutrients from DRP. The Kemzyme-H $F^{(R)} was used at rate of 0.1% of DRP. The selected concentrations of HCl, NaOH, and $H_2O_2$ were then used for treatment of DRP that was used in biological experiments. Two hundred and forty, day-old Hubbard male broiler chicks (38-40 g) were randomly divided into 48 experimental units with five chicks each. Each chemically treated DRP was incorporated into broiler diets at 10, 20 or 30% levels replacing yellow corn from the control feed and thus sixteen experimental feeds were prepared. These feeds were randomly assigned to 48 experimental units such that there were three replicates of chicks on each diet. The results of the study suggest that DRP can be effectively used in broiler diets at 20% level. The best weight gain and feed conversion ratio were observed with diet containing 20% level of DRP treated with 6% $H_2O_2$. The diets containing 30% levels of treated DRP were uneconomical, as excess use of oil was required to compensate the energy needs of the birds.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.5
• /
• pp.754-760
• /
• 2007

The effect of dehydrated food waste product (DFWP) inclusion in diets of Taiwan native chickens on the growth performance, carcass traits, clinical blood chemistry and nutrient digestibility was investigated with 320 male Taishi Native Chickens (Taishi No. 13). They were randomly allocated into four levels of DFWP inclusion (0, 5, 10, or 20%) treatment. Each treatment had 80 chickens with four replicates. At 15 weeks of age, 8 chickens were selected from each group for the nutrient digestibility trial. The results showed that body weight gain during the 0 to 4 week period decreased as the feed intake and feed conversion rate (FCR) increased linearly with increasing level of DFWP inclusion. During the 4 to 8 week period, greater body weight gains were recorded for the birds on the 5% DFWP inclusion level than for the control (p<0.05). During 8 to16 weeks, the feed intake and FCR increased linearly (p<0.05). Interestingly too, results of the carcass analysis showed that DFWP inclusion up to 20% in the diet significantly decreased the relative abdominal fat weight but increased the relative proventriculus and gizzard weights of the birds. However, other carcass parameters, meat quality and sensory scores were not significantly influenced by the dietary DFWP inclusion levels (p>0.05). Higher serum aspartate aminotransferase, ${\gamma}$-glutamyltransferase activity and crude protein digestibility, and lower gross energy digestibility were observed in the 20% DFWP group compared to the control (p<0.05). Dietary DFWP inclusion was inappropriate during the 0 to 4 week period. During 4 to 8 weeks, there was no adverse effect on chicken performance in the 20% group. There was no disadvantage on carcass properties and in the meat panel test. This result would not affect consumer determination.

• 한국태양에너지학회:학술대회논문집
• /
• 2012.03a
• /
• pp.96-101
• /
• 2012

An experimental study was conducted to investigate the performance of a concentrating photovoltaic cell (CPV) against temperature. It is know that a high efficiency of a CPV can be achieved only with proper cell temperature as well as high concentration ratio (CR). This study is concerned with appropriate cooling condition for a liquid-convection cooler for the best performance of a specific CPV. A series of experiments was conducted in a range of cell temperatures as a result of varying cooling conditions, while the concentration ratio was 390 and the solar irradiation flux was higher than 900 $W/m^2$ in outdoor environment. The CPV had a planar dimension of 10 by 10 mm. A Fresnel lens was used as a concentrator, of which the dimension was 221 mm(W) ${\times}$ 221 mm(L) ${\times}$ 3 mm(t) and the transmissivity was known to be 0.8. The cooler was attached to the bottom side of the CPV and had a contact area of 21 mm(W) ${\times}$ 26 mm(L), which was identical to the size of the base plate of the CPV. The coolant temperature was controlled by an isothermal bath and the flow rate was controlled and measured by a flowmeter. The experimental results showed that the average of power efficiency of the CPV decreased from 28.6 % to 24.7 % as the cell temperature increased from $36^{\circ}C$ to $97^{\circ}C$. An appropriate cooling method of a CPV might increase the power conversion efficiency by about 4% for the same concentration ratio. Discussion is included from the viewpoint of the combined efficiency in addition to the power efficiency.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.4
• /
• pp.557-564
• /
• 2009

Two experiments were conducted to evaluate the use of various levels of full-fat sunflower seeds (FFSS) on broiler performance and carcass characteristics. In the first experiment, FFSS was included in a basal diet at 70, 140, and 210 g/kg and the $AME_n$ values of the experimental diets were determined. The linear regression equation of $AME_n$ values on rate of inclusion was calculated. Extrapolation value for the $AME_n$ of FFSS at 100% inclusion was 14.22 MJ/kg. In the second experiment, diets containing various levels (0, 70, 140, and 210 g/kg) of FFSS were given to broilers (Ross strain) from 0 to 49 d. At 28 days of age, blood parameters and digestive enzyme activities were determined and carcass parameters were evaluated at 49 days of age. Weight gain, feed intake and feed conversion ratio (FCR) were improved (p<0.05) when broilers were fed various levels of FFSS in the starter and finisher diets. Breast, thigh, gastrointestinal tract and gizzard weight percentages were not affected by dietary treatments; however, liver weight percentage was decreased significantly (p<0.05) and weight of abdominal fat decreased but this effect was not significant. The activities of digestive enzyme (protease and ${\alpha}$-amylase) were not influenced by the treatments. Activity of alkaline phosphatase, concentrations of calcium, phosphorus, glucose, triglyceride, protein, high density lipoprotein (HDL) and low density lipoprotein (LDL) were not affected by incorporation of FFSS in the broiler diet. Although concentration of HDL increased and LDL decreased, these effects were not significant. The results of this study indicate that FFSS can be used at up to 21% in broiler diets without adverse effects on performance or other parameters of chickens.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.1
• /
• pp.127-130
• /
• 2004

Lathyrus sativus, locally known as Khesari, is a leguminous pulse crop grown in many parts of the world for food (used by poor people) and animal feed/fodder. Its seeds are rich in protein and energy but contains anti-nutritional factors prominent among which is ${\beta}$-N-Oxalylamino-L-Alanine (BOAA), a neurotoxin causing lathyrism in humans due to prolong consumption. Keeping in view the chemical characteristics of this toxin and literary facts on L. sativus feeding in terrestrial animals, it was hypothesized that aquatic species may better utilise this ingredient in mixed extruded diets. Diets were prepared with varying levels (0, 10, 18, 26 and 34%) of L. sativus seeds and fed for 60 days to study growth, body composition and digestibility of nutrients. Final body weight, specific growth rate and feed and protein conversion ratio did not differ (p>0.05) between treatments. Crude protein digestibility was reduced (p<0.01) beyond 26% inclusion level of L. sativus. Final carcass composition with regard to protein, lipid and ash did not differ (p>0.05) among the treatments. Comparable craniosomatic, viscerosomatic, renosomatic and hepatic indices and no mortality implies no apparent adverse effect on the vital organs and fish health. It was concluded that L. sativus can be a promising feed ingredient that can be used up to 34% or possibly higher level in fingerlings diet. To our knowledge, it appears to be the first report of its kind under laboratory conditions.

• Journal of Biosystems Engineering
• /
• v.27 no.6
• /
• pp.529-536
• /
• 2002

The performance of stilting engine, in particular, its energy conversion efficiencies are critically influenced by the regenerator characteristics. The regenerator characteristics are influenced by effectiveness, void fraction. heat transfer loss and fluid friction loss in the regenerator matrix. These factors were influenced by the surface geometry and material properties of the regenerator matrix. The regenerator design goals arc good heat transfer and low pressure drop of working Bas across the regenerator. Various data for designing a wire screen matrix have been given by Kays and London(1984). The mesh number of their experiment. however, was confined below the No. 60. which seems rather small for the Stirling engine applications. In this paper. in order to provide a basic data for the design of regenerator matrix, characteristics of heat transfer and flow friction loss were investigated by a packed mettled of matrix in oscillating flow as the same condition of operation in a Stirling engine. Seven kinds of sing1e wire screen meshes were used as the regenerator matrices. The results are summarized as follows; 1. While the working fluid flew slowly in the regenerator. the temperature difference was great at the both hot-blow(the working fluid flows from healer to cooler) and cold-blow(the working fluid flows from cooler to healer). On the other hand. while the working fluid flew fast. the temperature difference was not distinguished. 2. The No.150 wire screen used as the regenerator matrix showed excellent performance than tile others. 3. Phase angle variation and filling rate affected heat transfer or regenerator matrices. 4. Temperature difference between the inlet and outlet of the regenerator is very hish in degree of 120 phase angle.

• Korean Chemical Engineering Research
• /
• v.55 no.1
• /
• pp.86-92
• /
• 2017

A process, which converts carbon dioxide contained in the flue gas of coal-fired power plants to sodium bicarbonate, was studied experimentally and numerically. In this process, the carbon dioxide reacts with sodium hydroxide which is produced through saline water electrolysis. A bench scale reactor system was prepared for experiments of this process and numerical process modeling was performed for the bench scale reactor system. Comparing the process modeling results with the experimental data, responsibility of the process modeling was confirmed. Using this model, commercial scale process was simulated. Mass and energy balance of this process were calculated. Temperature profile in the reactor and carbon dioxide removal rate were obtained.