• Journal of Microbiology and Biotechnology
• /
• 제24권11호
• /
• pp.1542-1550
• /
• 2014

Co-digesting molasses wastewater and sewage sludge was evaluated for hydrogen production by response surface methodology (RSM). Batch experiments in accordance with various dilution ratios (40- to 5-fold) and waste mixing composition ratios (100:0, 80:20, 60:40, 40:60, 20:80, and 0:100, on a volume basis) were conducted. Volatile solid (VS) concentration strongly affected the hydrogen production rate and yield compared with the waste mixing ratio. The specific hydrogen production rate was predicted to be optimal when the VS concentration ranged from 10 to 12 g/l at all the mixing ratios of molasses wastewater and sewage sludge. A hydrogen yield of over 50 ml $H_2/gVS_{removed}$ was obtained from mixed waste of 10% sewage sludge and 10 g/l VS (about 10-fold dilution ratio). The optimal chemical oxygen demand/total nitrogen ratio for co-digesting molasses wastewater and sewage sludge was between 250 and 300 with a hydrogen yield above 20 ml $H_2/gVS_{removed}$.

• 한국정보처리학회논문지
• /
• 제6권12호
• /
• pp.3662-3674
• /
• 1999

본 논문에서는 대용량 병렬처리를 위한, 결함허용 다중칩을 이용해서 제조된 어레이시스템에서 여분장치 최적화와 관련된 설계문제를 다룬다. 수율과 신뢰성을 고려한 최적의 비용효과적인 다중칩 설계를 위한 새로운 계량적 방법을 제안하고 결함허용 다중칩의 운영신뢰성에 미치는 잠재여분의 효과를 분석한다. 특히 불완전한 지원회로, 칩조립수율과 어레이위상의 문제들에 대하여 논한다. 광범위에 걸친 분석결과에 따르면 제안한 방법은 수율과 신뢰성을 고려한 대용량 병렬처리 응용분야에 사용되는 다중칩 어레이 설계에 기존방법보다 매우 효율적으로 적용 가능하다.

• 한국유기농업학회지
• /
• 제19권spc호
• /
• pp.6-8
• /
• 2011

In order to produce the organic foods in accord with international standard, organic seeds should be used in organic farming. This study was conducted to establish the stable production of organic seed of waxy com by examining the growing characteristics, seed yield, and the economy for seed production by organic farming. The optimal sowing timing for organic seed production of waxy com hybrid was within 10 days of the $1^{st}$ of May with yield of 88~90% of conventional seed production. The optimal planting density was 41,600 plants/ha ($80{\times}30$ cm) for organic seed production of waxy com. The weight of 100 seeds and seed productivity increased at the planting ratio of 2:1 mother plant:male plant. Growth and seed production were improved by removing male plant at 7~10 days after silking. Organic fertilizer (mixed oil cake) was applied at a rate of 4~6 Mg/ha before sowing. Black plastic mulching was used for weed control. In addition, sex pheromone trap and bio-control agents were used for safe pest control and low labour cost.

• 한국수산과학회지
• /
• 제54권1호
• /
• pp.9-15
• /
• 2021

Sargassum serratifolium is a rich source of antioxidant meroterpenoids. The optimal extraction temperature and time for obtaining maximal antioxidant yield, antioxidant activity, and phenolic content from Sargassum serratifolium were determined using response surface methodology (RSM). The ranges of the independent variables for extraction temperature and time were 30-70℃ and 12-36 h, respectively. With increasing temperature and time, the yield increased significantly, while DPPH (2,2-dipheny-1-picrylhydrazyl) radical-scavenging activity and total phenolic content decreased significantly. The optimal extraction temperature and time obtained by RSM were 54℃ and 7 h, respectively, providing a yield of 8.2%, DPPH radical-scavenging activity of 60%, and total phenolic content of 163 mg GAE/g. The findings of this study provide useful information for the development of Sargassum serratifolium extraction processes for the food and cosmetic industries.

• 생약학회지
• /
• 제53권4호
• /
• pp.202-206
• /
• 2022

Salidroside is a major phenolic glycoside of Acer tegmentosum (Aceraceae) and known to be a hepatoprotective compound. Extraction conditions are one of the most important factors to save time and cost from an economic point of view. For this reason, this study was conducted to optimize the extraction condition for maximum yield of salidroside. For optimization, three extraction factors such as ethanol concentration (%), extraction temperature (℃), and solvent to material ratio (mg/mL) were tested and optimized for maximum yield of salidroside using response surface methodology (RSM). The optimal condition was obtained as an ethanol concentration of 53.4%, an extraction temperature at 67.11℃ and a solvent to material ratio (mg/mL), 195.55 mg/ml. The salidroside yield under optimal conditions was found to be 1.59 mg/g dried samples, which were well-matched with the predicted value of 1.56 mg/g dried samples. These results will provide useful information about optimized extraction conditions for the development of salidroside as hepatoprotective therapeutics.

• 한국초지조사료학회지
• /
• 제11권1호
• /
• pp.30-37
• /
• 1991

This experiment was conducted to determine optimal sowing date and method of Italian ryegrass(Lo1iuwr wzultiflorum. Tetrone) in paddy of Gyeong Nam area. Treatments given were four sowing dates(Sep. 30, Oct. 10, Oct. 20 and Oct. 30) and four sowing methods (broadcasting on tillage ridging, broadcasting on zerotillage ridging, boundless broadcasting and alternated drilling). The characteristics of growth, winter survival, yield(fresh and dry matter) and nutr~ent quality were observed. The results obtained are summarized as follows: 1. Winter survival and yield components such as plant height, and number of stem were the highest due to higher survival tillers at the sown time of Sep. 30(p<. 05). 2. Plants sown on Sep. 30 showed the highest fresh and dry matter yield. Yield was decreased as delaying the date of sowing. Fresh and dry matter yield sown on Oct. 10, were obtained 7600 and 1100 kg, respectively, aftenvardly sign~ficantly decreased(p< .05). 3. Effect of sowing time and method on chemical composition were not recognized. 4. Winter surviva: sown on boundless-broadcasting was lower(p<. 05) than those of sown on broadcasting on ridging and alternated-drilling. 5. Fresh and dry matter y~elds were the highest when sown on broadcasting on tillage ridging but that of sown on houndless-broadcasting was relatively low. 6. The growth and forage yield were enhanced by sowing up to Oct. 10 and by sown on broadcasting on ridging (tillage or zerotillage).

• Earthquakes and Structures
• /
• 제23권4호
• /
• pp.363-371
• /
• 2022

Traditional metal dampers have disadvantages such as a higher yield point and inadequate adjustability. The experimental results show that the low yield point steel has superior energy dissipation hysteretic capacity and can be applied to seismic structures. To overcome these deficiencies, a novel compound metal damper comprising both low yield point steel plates and common steel plates is presented. The optimization objectives, including "maximum rigidity" and "full stress state", are proposed to obtain the optimal edge shape of a compound metal damper. The numerical results show that the optimized composite metal damper has the advantages such as full hysteresis curve, uniform stress distribution, more sufficient energy consumption, and it can adjust the yield strength of the damper according to the engineering requirements. In view of the mechanical characteristics of the compound metal damper, the equivalent model of eccentric cross bracing is established, and the approximate analytical solution of the yield strength and the yield displacement is proposed. A nonlinear simulation analysis is carried out for the overall aseismic capacity of three-layer-frame structures with a compound metal damper. It is verified that a compound metal damper has better energy dissipation capacity and superior seismic performance, especially for a damper with double-objective optimized shape.

• 대한기계학회논문집B
• /
• 제24권4호
• /
• pp.589-598
• /
• 2000

A pilot-scale Spray Drying Sorber (SDS) system was set up to evaluate the effect of spray characteristics on the desulfurization yield. The size distribution and the Sauter Mean Diameters of slurry droplets were measured in advance using the optical size measurement system, Malvern 2600. The desulfurization yield of the drying chamber by size was measured for the conditions of inlet gas and spray injection. As a reagent, 10% limestone slurry of $Ca(OH)_2$ was treated with flue gas containing $SO_2$, and the combustion gas analyzer and gas detectors were attached to measure the $SO_2$ concentration. With a flow rate of 144 Nm3/h and a temperature range of $200{\sim}300^{\circ}C$, the experiments were performed for the Stoichiometric Ratio (SR) of 1.0 to 3.0 and droplet mean diameter of 6.5 to $34.3{\mu}m$. In case of smaller spray droplets, the desulfurization efficiency improved due to the increase of total droplet surface area, while the reduction in evaporation time reduced the contact time between the droplets and $SO_2$ gas. In some typical region of droplet diameter, this negative effect, reduction of contact time, became dominant and the desulfurization yield decreases the desulfurization yield in spite of the expansion in absorption area. These results revealed that there exists the optimal size of spray droplets for a given state, which is determined by the compromise between the total surface area of slurry droplets and the evaporation time of droplets. The measurements also indicated that the inlet temperature of flue gas changes the optimal injection condition by varying the driving force for evaporation. The results confirm that the effect of the evaporation time of slurry droplets should be considered in analyzing the desulfurization yield as well as the total surface area, for it is a significant aspect of the correlation with the capabilities of $SO_2$ absorption in wet droplets. In conclusion, the optimal condition of spray can be determined based on these results, which might be applied to design or scale-up of SDS system.

• Environmental Engineering Research
• /
• 제15권3호
• /
• pp.129-134
• /
• 2010

The optimization of experimental parameters, such as catalyst type, catalyst concentration, molar ratio of alcohol to oil and reaction temperature, on the transesterification for the production of rapeseed methyl ester has been studied. The Taguchi approach (Taguchi method) was adopted as the experimental design methodology, which was adequate for understanding the effects of the control parameters and to optimize the experimental conditions from a limited number of experiments. The optimal experimental conditions obtained from this study were potassium hydroxide as the catalyst, at a concentration of 1.5 wt %, and a reaction temperature of $60^{\circ}C$. According to Taguchi method, the catalyst concentration played the most important role in the yield of rapeseed methyl ester. Finally, the yield of rapeseed methyl ester was improved to 96.7% with the by optimal conditions of the control parameters which were obtained by Taguchi method.

• 산업경영시스템학회지
• /
• 제19권40호
• /
• pp.241-252
• /
• 1996

Almost of the pattern nesting for materials cutting plan, in footwear cutting process, is dependent on worker's experience. Thus, it is different from the real cutting results in degree of worker's skill. Therefore, it needs to develope the auto nesting systems that are easier for novice to use and fit for the domestic circumstances, This paper describes the development of auto pattern nesting system for optimal cutting yield of footwear materials. The system developed in this study is composed of interrelated modules for materials information control, nesting simulation, utility and the architecture of system, the functions of each module, and the information processing procedures of each function are discussed.