• Fisheries and Aquatic Sciences
• /
• 제23권4호
• /
• pp.11.1-11.11
• /
• 2020

We tried to find the optimal growth conditions of sea cucumber and to analyze the economic effectiveness of the sea cucumber seedling release project in Korea. We first examined the optimal growth conditions of sea cucumber in the relating literatures. Then, we analyzed the economic effectiveness of the sea cucumber seedling release project of the Woncheon fishing village union of Gyeongnam Province in 2016-2018 by using the cost benefit analysis method. The net income of the release project of the Woncheon fishing village union was 69,850 Korean won. The benefit to cost ratio of the sea cucumber seedling release project of the Woncheon fishing village union was estimated to be 1.7, indicating that the project was economically feasible. In order to improve the economic feasibility of the sea cucumber release project, as we see in the case of the Woncheon fishing village union, it is necessary to manage the purchase of the sea cucumber seedling, to improve the recapture rate of sea cucumber, and to manage marketing of sea cucumber.

• Journal of Microbiology and Biotechnology
• /
• 제16권12호
• /
• pp.1856-1861
• /
• 2006

A Bacillus sp. A-6 strain that produced xylanase was isolated from rice bran. The optimal temperature and pH for xylanase activity of the culture supernatant of Bacillus sp. A-6 were 40$^{\circ}C$ and pH 7, respectively. The optimal temperature and pH for xylanase production in the xylan medium were 30$^{\circ}C$ and pH 9, respectively. The optimal concentrations of oat spelt xylan and peptone for xylanase production were 0.5% and 1.5%, respectively. The best nitrogen sources for xylanase production was beef extract, but xylanase production was also supported comparably by tryptone and peptone. The bacterial growth in the optimal xylan medium reached stationary growth phase after 12 h of incubation. The xylanase production in the culture supernatant increased dramatically during the initial 12 h exponential growth phase and then remained constant at 23.8-24.5 unit/ml during the stationary growth phase. The pH of the culture medium decreased from 8.8 to 6.7 during the exponential growth phase and subsequently increased to 8.1 during the stationary growth phase. Rice bran, sorghum bran, and wheat bran as well as oat spelt xylan induced xylanase production. The xylanase production was repressed when glucose was added to the xylan-containing medium.

• 한국균학회지
• /
• 제29권1호
• /
• pp.52-60
• /
• 2001

This study was carried out to obtain the basic data on artificial culture of Hohenbuehelia petaloides. The optimum medium are glucose peptone medium (GP), Hennerberg medium, Phellinus igniarius medium (PIM), Lentinus edodes medium (LEM), Czapek dox medium. The optimum condition for the mycelial growth was $30^{\circ}C$ and pH 6.0. The carbon sources such as dextrine, fructose and lactose were favorable to mycelial growth. The optimal concentrations of carbon sources are 10% dextrin and fructose. As nitrogen sources, tryptone, casamino acid and histidine appeared to be favorable. The optimal concentrations of nitrogen sources are 1% soy tone and 0.3% ammonium nitrate. The optimal concentration of yeast extract is 0.4%. The mineral nutrients of $KH_2PO_4$, $K_2HPO_4\;and\;MgSO_4{\cdot}7H_2O$ were effective and the optimal concentrations were 0.046, 0.1 and 0.05%, respectively.

• 한국토양비료학회지
• /
• 제49권5호
• /
• pp.548-554
• /
• 2016

Optimal range of soil physical quality to enhance crop productivity or to improve environmental health is still in dispute for the upland soil. We hypothesized that the optimal range might be established by comparing soil physical parameters and their interactions inhibiting crop growth. The parameter identifying optimal range covered favorable conditions of aeration, permeability and root extension. To establish soil physical standard two experiments were conducted as follows; 1) investigating interactions of bulk density and aeration porosity in the laboratory test and 2) determining effects of soil compaction and deep & conventional tillage on physical properties and crop growth in the field test. The crops were Perilla frutescens, Zea mays L., Solanum tuberosum L. and Secale cereael. The saturated hydraulic conductivity, bulk density from the root depth, root growth and stem length were obtained. Higher bulk density showed lower aeration porosity and hydraulic conductivity, and finer texture had lower threshold bulk density at 10% aeration bulk density. Reduced crop growth by subsoil compaction was higher in silt clay loam compared to other textures. Loam soil had better physical improvement in deep rotary tillage plot. Combined with results of the present studies, the soil physical quality was possibly assessed by bulk density index. Threshold subsoil bulk density as the upper value were $1.55Mg\;m^{-3}$ in sandy loam, $1.50Mg\;m^{-3}$ in loam and $1.45Mg\;m^{-3}$ in silty clay loam for optimal soil physical quality in upland.

• 한국미생물·생명공학회지
• /
• 제18권4호
• /
• pp.394-400
• /
• 1990

유전자 조작된 세포 발효공정의 생산수율을 최대화하기 위하여 세포의 성장속도와 제품 생성속도간의 상반관계를 고려하여야 한다. 유전자 조작된 E.coli 발효에 있어, 최적화 이론을 적용하여 두 속도의 가중치를 결정함으로써 생산수율의 최대화를 꾀하였다. 성장저해제의 농도는 비 성장속도를 조절하고 결국 융합된 유전자의 발현 속도를 조절하는 변수로 사용되다. 이런 system의 특성을 위하여 간단한 unstructured model를 사용하였다.

• 한국균학회지
• /
• 제28권2호
• /
• pp.73-80
• /
• 2000

공시배지 중 MYPA 배지에서 큰느타리의 균사생장 및 밀도가 가장 양호하였으며, 균사생장 최적온도는 $25^{\circ}C$이고, 최적 pH는 6.0이었다. 최적 회전진탕배양 일수는 7일이었고, 큰느타리의 균사생장을 위한 최적배지조성은 탄소원 soluble starch 3%(w/v), 질소원 malt extract 0.25%(w/v), yeast extract 0.25%(w/v), 무기염류 $CaCl_2{\cdot}2H_2O$ 0.05%(w/v)이었다. 기본배지인 MYP 배지와 최적 배지로 액체배양하여 균체량을 비교한 결과, 최적배지에서 균체생산량 및 생장수율이 높았다. 큰느타리의 균사생장과 균밀도에 최적인 톱밥수종은 참나무 톱밥이었고, 첨가제는 미강과 밀기울 30%(v/v)이었으며, 최적 수분함량은 70%(v/v)이었다. 반면에 자실체 생산을 위한 최적 첨가제는 발겨 20%(v/v)이었다.

• Journal of Biosystems Engineering
• /
• 제24권5호
• /
• pp.445-452
• /
• 1999

This study was conducted to develop a searching algorithm for optimal daily temperature setpoint greenhouse. An algorithm using crop growth and energy models was developed to determine optimum crop growth environment. The results of this study were as follows: 1. Mathematical models for crop growth and energy consumption were derived to define optimal daily temperature setpoint. 2. Optimum temperature setpoint, which could maximize performance criterion, was determined by using Pontryagin maximum principle. 3. Dynamic control of daily temperature using the developed algorithm showed higher performance criterion than static control with fixed temperature setpoint. Performance criteria for dynamic control models were with simulated periodic weather data and with real weather data, increased by 48% and 60%, respectively.

• Mycobiology
• /
• 제37권2호
• /
• pp.103-108
• /
• 2009

The principal objective of this study was to acquire basic data regarding the mycelial growth characteristics for the artificial cultivation of Coprinus comatus. 12 URP primers were employed to evaluate the genetic relationships of C. comatus, and the results were divided into three groups. Among six kinds of mushroom media, MYP medium was selected as the most favorable culture medium for C. comatus. The optimal temperature and pH ranges for the mycelial growth of C. comatus were $23{\sim}26^{\circ}C$ and pH 6${\sim}$8, respectively. The carbon and nitrogen sources for optimal mycelial growth were sucrose and tryptone, respectively.

• 대한기계학회논문집B
• /
• 제26권7호
• /
• pp.945-950
• /
• 2002

Shape optimization of a flow system is done to obtain the required effects, in the engineering fields. Most of these designs are accomplished by empirical or numerical analysis. In empirical analysis, it is difficult to obtain an optimal shape in the feasible design region. And, in numerical method, it usually needs much calculation expenses for shape optimization, because of design sensitivity analysis. In this study, we used the growth-strain method having only one distributed parameter such as a design variable. It optimizes a shape by making a distributed parameter such as dissipation energy uniform in a flow system, and then applied to two-flow systems. In order to overcome the stability occurred in numerical analysis performed by Azegami, the equation of volumic strain has been modified. Also, the shapes were compared with the known optimal shapes for the flow systems. Consequently, we confirm that the modified growth-strain method is very efficient and practical in shape optimization of the flow systems.

• Fisheries and Aquatic Sciences
• /
• 제26권9호
• /
• pp.525-534
• /
• 2023

Vitamin C plays an important role for fish survival, growth and disease resistance. However, the optimal vitamin C for rearing red drum Sciaenops ocellatus juveniles in Vietnam is not known. To address this issue, a 70-day feeding trial was conducted to evaluate the optimal dietary vitamin C requirements for red drum juveniles. Seven isonitrogenous (55.35% protein) and isolipidic (9.07% lipid) diets were formulated to include graded vitamin C concentrations of 23.2, 124.5, 235.2, 423.8, 626.7, 824.6, and 1,027.3 mg/kg, respectively. The results showed that fish fed on 423.8 mg/kg vitamin C diet had the highest growth rate, which can be linked to the increased feed utilization. Broken-line analysis indicated that the optimal dietary vitamin C requirements of red drum juveniles were 342.92 and 405.80 mg/kg for growth parameters, feed utilization, body composition and biochemical parameters of serum. Based on these parameters the optimal vitamin C supplementation level for red drum juveniles was estimated in the range of 342.92-405.80 mg/kg vitamin C in the diets with direct applications in producing artificial feed for rearing juveniles of this species in Vietnam.