• Title/Summary/Keyword: Heat distribution

Search Result 2,932, Processing Time 0.031 seconds

Distribution and Changes of Amino Acids and Related Compounds in the Muscle Extract of the Right-eye Flounder during Heat Treatment (가자미류 육엑스분중의 아미노산 및 그 관련화합물의 분포와 가열조건에 따른 변화)

  • Moon, Soo-Kyung;An, Mi-Jeung;Han, Young-Sil;Pyeun, Jae-Hyung
    • Korean journal of food and cookery science
    • /
    • v.6 no.3 s.12
    • /
    • pp.43-50
    • /
    • 1990
  • Distribution of amino acids and related compounds in the muscle extract of seven species of right-eye flounder (spotted halibut, slime flounder, marbled sole, sand flounder, stone flounder, frog fleunder and bastard halibut) were studied. The effect of heat treatment on quantitative change in the composition of amino acids and related compounds in the extract of sand fleunder muscle was also investigated since the sand flounder has much Ex-nitrogen in the extract of the muscle. The content of crude protein and that of pure protein were in the range of $17.54{\sim}19.99%$ and $15.63{\sim}17.95%$, respectively. Among the extracts of the seven fish muscle, stone flounder showed the highest content of Ex-nitrogen(2.12%). In the muscle extracts of the seven fish taurine was abundantly contained $(29.4{\sim}56.9%)$, and followed alanine $(6.6{\sim}10.4%)$ and glycine $(1.6{\sim}16.7%)$. The compositions of amino acids and related compounds were characterized by the existence of phosphoethanolamine, ${\alpha}-aminoadipic\;acid$, DL-allocystathionine, ethanolamine and ornithine. The experiments on amino acids and related compounds of the muscle extract of sand flounder with reference to heating time and temperature were resulted in that the amount of taurine, tyrosine, leucine and alanine were increased with the heating time at $100^{\circ}C$, whereas that of lysine, histidine, ${\alpha}-aminoadipic\;acid$ and proline were decreased with prolonged heating time. When heating temperature was changed from $90^{\circ}C$ to $130^{\circ}C$ for 60 min, the contents of taurine, alanine and leucine were increased, while that of histidine, lysine and aspartic acid were decreased.

  • PDF

Anti-listeria Activity of Lactococcus lactis Strains Isolated from Kimchi and Characteristics of Partially Purified Bacteriocins (김치에서 분리한 Lactococcus lactis 균주의 항리스테리아 활성 및 부분 정제된 박테리오신의 특성)

  • Son, Na-Yeon;Kim, Tae-Woon;Yuk, Hyun-Gyun
    • Journal of Food Hygiene and Safety
    • /
    • v.37 no.2
    • /
    • pp.97-106
    • /
    • 2022
  • Listeria monocytogenes (L. monocytogenes) is one of gram-positive foodborne pathogens with a very high fatality rate. Unlike most foodborne pathogens, L. monocytogenes is capable of growing at low temperatures, such as in refrigerated foods. Thus, various physical and chemical prevention methods are used in the manufacturing, processing and distribution of food. However, there are limitations to the methods such as possible changes to the food quality and the consumer awareness of synthetic preservatives. Thus, the aim of this study was to evaluate the anti-listeria activity of lactic acid bacteria (LAB) isolated from kimchi and characterize the bacteriocin produced by Lactococcuslactis which is one of isolated strains from kimchi. The analysis on the anti-listeria activity of a total of 36 species (Lactobacillus, Weissella, Lactobacillus, and Lactococcus) isolated from kimchi by the agar overlay method revealed that L. lactis NJ 1-10 and NJ 1-16 had the highest anti-listeria activity. For quantitatively analysis on the anti-listeria activity, NJ 1-10 and NJ 1-16 were co-cultured with L. monocytogenes in Brain Heat Infusion (BHI) broth, respectively. As a result, L. monocytogenes was reduced by 3.0 log CFU/mL in 20 h, lowering the number of bacteria to below the detection limit. Both LAB strains showed anti-listeria activity against 24 serotypes of L. monocytogenes, although the sizes of clear zone was slightly different. No clear zone was observed when the supernatants of both LAB cultures were treated with proteinase-K, indicating that their anti-listerial activities might be due to the production of bacteriocins. Heat stability of the partially purified bacteriocins of NJ 1-10 and NJ 1-16 was relatively stable at 60℃ and 80℃. Yet, their anti-listeria activities were completely lost by 60 min of treatment at 100℃ and 15 min of treatment at 121℃. The analysis on the pH stability showed that their anti-listeria activities were the most stable at pH 4.01, and decreased with the increasing pH value, yet, was not completely lost. Partially purified bacteriocins showed relatively stable anti-listeria activities in acetone, ethanol, and methanol, but their activities were reduced after chloroform treatment, yet was not completely lost. Conclusively, this study revealed that the bacteriocins produced by NJ 1-10 and NJ 1-16 effectively reduced L. monocytogenes, and that they were relatively stable against heat, pH, and organic solvents, therefore implying their potential as a natural antibacterial substance for controlling L. monocytogenes in food.

Analysis of Spatial Correlation between Surface Temperature and Absorbed Solar Radiation Using Drone - Focusing on Cool Roof Performance - (드론을 활용한 지표온도와 흡수일사 간 공간적 상관관계 분석 - 쿨루프 효과 분석을 중심으로 -)

  • Cho, Young-Il;Yoon, Donghyeon;Lee, Moung-Jin
    • Korean Journal of Remote Sensing
    • /
    • v.38 no.6_2
    • /
    • pp.1607-1622
    • /
    • 2022
  • The purpose of this study is to determine the actual performance of cool roof in preventing absorbed solar radiation. The spatial correlation between surface temperature and absorbed solar radiation is the method by which the performance of a cool roof can be understood and evaluated. The research area of this study is the vicinity of Jangyu Mugye-dong, Gimhae-si, Gyeongsangnam-do, where an actual cool roof is applied. FLIR Vue Pro R thermal infrared sensor, Micasense Red-Edge multi-spectral sensor and DJI H20T visible spectral sensor was used for aerial photography, with attached to the drone DJI Matrice 300 RTK. To perform the spatial correlation analysis, thermal infrared orthomosaics, absorbed solar radiation distribution maps were constructed, and land cover features of roof were extracted based on the drone aerial photographs. The temporal scope of this research ranged over 9 points of time at intervals of about 1 hour and 30 minutes from 7:15 to 19:15 on July 27, 2021. The correlation coefficient values of 0.550 for the normal roof and 0.387 for the cool roof were obtained on a daily average basis. However, at 11:30 and 13:00, when the Solar altitude was high on the date of analysis, the difference in correlation coefficient values between the normal roof and the cool roof was 0.022, 0.024, showing similar correlations. In other time series, the values of the correlation coefficient of the normal roof are about 0.1 higher than that of the cool roof. This study assessed and evaluated the potential of an actual cool roof to prevent solar radiation heating a rooftop through correlation comparison with a normal roof, which serves as a control group, by using high-resolution drone images. The results of this research can be used as reference data when local governments or communities seek to adopt strategies to eliminate the phenomenon of urban heat islands.

A Study on the Wind Ventilation Forest Planning Techniques for Improving the Urban Environment - A Case Study of Daejeon Metropolitan City - (도시환경 개선을 위한 바람길숲 조성 계획기법 개발 연구 - 대전광역시를 사례로 -)

  • Han, Bong-Ho;Park, Seok-Cheol;Park, Soo-Young
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.51 no.2
    • /
    • pp.28-41
    • /
    • 2023
  • The objective of the study was to develop an Urban Windway Forest Creation Planning Technique for the Improvement of the Urban Environment using the case of Daejeon Metropolitan City. Through a spatial analysis of fine dust and heat waves, a basin zone, in which the concentration was relatively serious, was derived, and an area with the potential of cold air flow was selected as the target area for the windway forest development by analyzing the climate and winds in the relevant zone. Extreme fine dust areas included the areas of the Daejeon Industrial Complex Regeneration Business District in Daedeok-gu and Daedeok Techno Valley in Yuseong-gu. Heat wave areas included the areas of Daedeok industrial Complex in Moksang-dong, the Daejeon Industrial Complex Regeneration Business District in Daehwa-dong, and the high-density residential area in Ojeong-dong. As a result of measuring the wind speeds in Daejeon with an Automatic Weather System, the average wind speeds during the day and night were 0.1 to 1.7 m/s,, respectively. So, a plan of for a windway forest that smoothly induces the movement of cold air formed in outer forests at night is required. The fine dust/heat wave intensive management zones of Daejeon Metropolitan City were Daejeoncheon, Yudeungcheon, Gapcheon-Yudeungcheon, and Gapcheon. The windway forest formation plan case involved the old city center of Daejeon Metropolitan City among the four zones, the Gapcheon-Yudeungcheon area, in which the windway formation effect was presumed to be high. The Gapcheon-Yudeungcheon area is a downtown area that benefits from the cold and fresh air generated on Mt. Gyejok and Mt. Wuseong, which are outer forests. Accordingly, the windway forest was planned to spread the cold air to the city center by connecting the cold air generated in the Seosa-myeon forest of Mt. Gyejok and the Namsa-myeon forest of Mt. Wuseong through Gapcheon, Yudeungcheon, and street forests. After selecting the target area for the wind ventilation forest, a climate map and wind formation function evaluation map were prepared for the area, the status of variation wind profiles (night), the status of fine dust generation, and the surface temperature distribution status were grasped in detail. The wind ventilation forest planning concept and detailed target sites by type were identified through this. In addition, a detailed action plan was established according to the direction of creation and setting of the direction of creation for each type of wind ventilation forest.

Distribution of Indicator Organisms and Influence of Storage Temperature and Period in Commercial Animal Foods (시판 동물성 식품의 오염지표세균 분포 및 저장온도, 기간별 오염지표세균의 변화)

  • 이용욱;박석기
    • Journal of Food Hygiene and Safety
    • /
    • v.13 no.4
    • /
    • pp.430-440
    • /
    • 1998
  • The average number of total viable counts for the commercial pork tested was 19/g, coliform 1.8/g, psychrophilic bacteria 15/g, heterotrophic bacteria 12/g, fecal streptococcus 6.2/100 g, Pseudomonas aeruginosa 13/100 g and none of heat-resistant bacteria and Staphylococcus was detected. That for the commercial beef tested was 130/g, coliform 5.2/g, psychrophile 140/g, heterotroph 28/g, Staphylococcus 1.2/g, fecal streptococcus 9.5/100 g, Pseud. aeruginosa 1.9/100 g and heat-resistant bacteria was not detected. That for the commercial chicken tested was 8800/g, coliform 53/g, psychrophile 4600/g, heterotroph 4700/g, fecal streptococcus 9.9/100 g, Pseudo aeruginosa 2.5/100 g. That for milk was 4700/ml, psychrophile 120/ml, heterotroph 420/ml and the others were not detected. That for the commercial cheese was 3.2/g, psychrophile 2.3/g, heterotroph 1.6/g, Staphylococcus l/g, fecal streptococcus 9.1/g. That for fermented milk was $10^{7}/ml$, heatresistant bacteria $10^{6}/ml$, fecal streptococcus 2400/100 ml, lactobacillus $3.2{\times}10^{15}/ml$, in accordance with lactic acid bacteria and the others were not detected. There was not detected any indicator organisms from ham, sausage, butter, eggs and quails in the commercial fooods tested. SPC, coliform, psychrophile and heterotroph in commercial meats stored at $10^{\circ}C$ were increased rapidly as time goes on but heat-resistant bacteria, staphylococcus, fecal streptococcus and Pseudo aeruginosa were constant. At $20^{\circ}C$, SPC, coliform, psychrophile, heterotroph and fecal streptococcus were the highest at 7 days and heat-resistant bacteria, staphylococcus and Pseudo aeruginosa were increased a little. At $30^{\circ}C$, all indicators were increased rapidly for 3 and 7 days and then decreased rapidly. All indicator organisms were increased at the level of 10/g for 14 days in meat products stored at $10^{\circ}C$, but SPC, psychrophile and heterotroph in meat products stored at $20^{\circ}C$ were increased at the level of $lO^5/g$. It showed that the indicators in meat products stored at $30^{\circ}C$ had a tendency to increase at the level of $10^{2}/g$ relative to those stored at $20^{\circ}C$. SPC, psychrophile and heterotroph in milk stored at $10^{\circ}C$ increased up to the level of $10^4/ml$, but coliform, staphylococcus, fecal streptococcus and Pseudo aeruginosa were not detected. As stored at $20^{\circ}C$ and $30^{\circ}C$, they were increased rapidly for 1 or 3 days and then constant for a long time.

  • PDF

The Study on Bunsen Reaction Process for Iodine-Sulfur Thermochemical Hydrogen Production (요오드-황 열화학 수소 제조를 위한 분젠 반응 공정 연구)

  • Kang, Young-Han;Ryu, Jae-Chun;Park, Chu-Sik;Hwang, Gab-Jin;Lee, Sang-Ho;Bae, Ki-Kwang;Kim, Young-Ho
    • Korean Chemical Engineering Research
    • /
    • v.44 no.4
    • /
    • pp.410-416
    • /
    • 2006
  • For highly efficient operation of a Bunsen process section in an iodine-sulfur thermochemical hydrogen production cycle using nuclear heat, the process characteristics of $H_2SO_4-HI-H_2-O-I_2$ mixture system for separating into two liquid phases ($H_2SO_4$-rich phase and $HI_x$-rich phase) and the distribution of $H_2O$ to each phase were investigated.The experiments for process variables were carried out in the temperature range, from 298 to 353 K, and in the $H_2SO_4/HI/H_2O/I_2$ molar ratio of 1/2/14~20/0.5~8.0. As the results, for the $SO_2-I_2-H_2O$ Bunsen reaction system, the ranges between the starting point and the saturation point for two liquid phases separation were determined by calculation. The best result for the minimization of impurities (HI and $I_2$ in $H_2SO_4$ phase and $H_2SO_4$ in $HI_x$ phase) in each phase was obtained in an optimum condition with the highest temperature of 353 K and the highest $I_2$ molar composition. In this condition, the $HI/H_2SO_4$ molar ratio in the $H_2SO_4$-rich phase and the $H_2SO_4/HI_x$ molar ratio in the $HI_x$-rich phase were 0.024 and 0.028, respectively. For the distribution of $H_2O$ to each phase, it is appeared that the affinity between $HI_x$ and $H_2O$ was more superior to that between $H_2SO_4$ and $H_2O$. The affinity between $HI_x$ and $H_2O$ was decreased with increasing temperature but increased with increasing $I_2$ molar composition.

The Contribution of Innovation Activity to the Output Growth of Emerging Economies: The Case of Kazakhstan

  • Smagulova, Sholpan;Mukasheva, Saltanat
    • Journal of Distribution Science
    • /
    • v.10 no.7
    • /
    • pp.33-41
    • /
    • 2012
  • The purpose of this study is to analyse the state of the energy industry and to determine the efficiency of its functioning on the basis of energy conservation principle and application of innovative technologies aimed at improving the ecological modernisation of agricultural sectors of Kazakhstan. The research methodology is based on an integrated approach of financial and economic evaluation of the effectiveness of the investment project, based on calculation of elasticity, total costs and profitability, as well as on comparative, graphical and system analysis. The current stage is characterised by widely spread restructuring processes of electric power industry in many countries through introduction of new technical installations of energy facilities and increased government regulation in order to enhance the competitive advantage of electricity market. Electric power industry features a considerable value of creating areas. For example, by providing scientific and technical progress, it crucially affects not only the development but also the territorial organisation of productive forces, first of all the industry. In modern life, more than 90% of electricity and heat is obtained by Kazakhstan's economy by consuming non-renewable energy resources: different types of coal, oil shale, oil, natural gas and peat. Therefore, it is significant to ensure energy security, as the country faces a rapid fall back to mono-gas structure of fuel and energy balance. However, energy resources in Kazakhstan are spread very unevenly. Its main supplies are concentrated in northern and central parts of the republic, and the majority of consumers of electrical power live in the southern and western areas of the country. However, energy plays an important role in the economy of industrial production and to a large extent determines the level of competitive advantage, which is a promising condition for implementation of energy-saving and environmentally friendly technologies. In these circumstances, issues of modernisation and reforms of this sector in Kazakhstan gain more and more importance, which can be seen in the example of economically sustainable solutions of a large local monopoly company, significant savings in capital investment and efficiency of implementation of an investment project. A major disadvantage of development of electricity distribution companies is the prevalence of very high moral and physical amortisation of equipment, reaching almost 70-80%, which significantly increases the operating costs. For example, while an investment of 12 billion tenge was planned in 2009 in this branch, in 2012 it is planned to invest more than 17 billion. Obviously, despite the absolute increase, the rate of investment is still quite low, as the total demand in this area is at least more than 250 billion tenge. In addition, industrial infrastructure, including the objects of Kazakhstan electric power industry, have a tangible adverse impact on the environment. Thus, since there is a large number of various power projects that are sources of electromagnetic radiation, the environment is deteriorated. Hence, there is a need to optimise the efficiency of the organisation and management of production activities of energy companies, to create and implement new technologies, to ensure safe production and provide solutions to various environmental aspects. These are key strategic factors to ensure success of the modern energy sector of Kazakhstan. The contribution of authors in developing the scope of this subject is explained by the fact that there was not enough research in the energy sector, especially in the view of ecological modernisation. This work differs from similar works in Kazakhstan in the way that the proposed method of investment project calculation takes into account the time factor, which compares the current and future value of profit from the implementation of innovative equipment that helps to bring it to actual practise. The feasibility of writing this article lies in the need of forming a public policy in the industrial sector, including optimising the structure of energy disbursing rate, which complies with the terms of future modernised development of the domestic energy sector.

  • PDF

A study on the change effect of emission regulation mode on vehicle emission gas (배기가스 규제 모드 변화가 차량 배기가스에 미치는 영향 연구)

  • Lee, Min-Ho;Kim, Ki-Ho;Lee, Joung-Min
    • Journal of the Korean Applied Science and Technology
    • /
    • v.35 no.4
    • /
    • pp.1108-1119
    • /
    • 2018
  • As the interest on the air pollution is gradually rising at home and abroad, automotive and fuel researchers have been studied on the exhaust and greenhouse gas emission reduction from vehicles through a lot of approaches, which consist of new engine design, innovative after-treatment systems, using clean (eco-friendly alternative) fuels and fuel quality improvement. This research has brought forward two main issues : exhaust emissions (regulated and non-regulated emissions, PM particle matter) and greenhouse gases of vehicle. Exhaust emissions and greenhouse gases of automotive had many problem such as the cause of ambient pollution, health effects. In order to reduce these emissions, many countries are regulating new exhaust gas test modes. Worldwide harmonized light-duty vehicle test procedure (WLTP) for emission certification has been developed in WP.29 forum in UNECE since 2007. This test procedure was applied to domestic light duty diesel vehicles at the same time as Europe. The air pollutant emissions from light-duty vehicles are regulated by the weight per distance, which the driving cycles can affect the results. Exhaust emissions of vehicle varies substantially based on climate conditions, and driving habits. Extreme outside temperatures tend to increasing the emissions, because more fuel must be used to heat or cool the cabin. Also, high driving speeds increases the emissions because of the energy required to overcome increased drag. Compared with gradual vehicle acceleration, rapid vehicle acceleration increases the emissions. Additional devices (air-conditioner and heater) and road inclines also increases the emissions. In this study, three light-duty vehicles were tested with WLTP, NEDC, and FTP-75, which are used to regulate the emissions of light-duty vehicles, and how much emissions can be affected by different driving cycles. The emissions gas have not shown statistically meaningful difference. The maximum emission gas have been found in low speed phase of WLTP which is mainly caused by cooled engine conditions. The amount of emission gas in cooled engine condition is much different as test vehicles. It means different technical solution requires in this aspect to cope with WLTP driving cycle.

Changes in Distribution of Debris Slopes and Vegetation Characteristics in Mudeungsan National Park (무등산국립공원의 암설사면 분포변화 및 식생 특성)

  • Seok-Gon Park;Dong-Hyo Kim
    • Korean Journal of Environment and Ecology
    • /
    • v.37 no.1
    • /
    • pp.1-12
    • /
    • 2023
  • We analyzed the distribution area of debris slopes in Mudeungsan (Mt. Mudeung) National Park by comparing aerial photos of the past (1966) and the present (2017) and identified the vegetation characteristics that affect the change in the area of the debris slopes by investigating the vegetation status of the debris slopes and the surrounding areas. The area of debris slopes in Mt. Mudeung appears to have been reduced to a quarter of what it used to be. Debris slopes here have decreased at an average rate of 2.3 ha/yr over 51 years by vegetation covers. Notably, most of the small-area debris slopes in the low-inclination slopes disappeared due to active vegetation coverage. However, there are still west-facing, south-west-facing, south-facing, and large-area debris slopes remaining because the sun's radiant heat rapidly raises the surface temperature of rock blocks and dries moisture, making tree growth unfavorable. Because of these locational characteristics, the small-scale vegetation in the middle of Deoksan Stony Slope, which is the broadest area, showed distinct characteristics from the adjacent forest areas. Sunny places and tree species with excellent drying resistance were observed frequently in Deoksan Stony Slope. However, tree species with high hygropreference that grow well in valleys with good soil conditions also prevailed. In some of these places, the soil layer has been well developed due to the accumulation of fine materials and organic matter between the crevices of the rock blocks, which is likely to have provided favorable conditions for such tree species to settle and grow. At the top of Mt. Mudeung, on the other hand, the forest covered the debris slopes, where Mongolian oaks (Quercus mongolica) and royal azaleas (Rhododendron schlippenbachii), which typically grow in the highlands, prevailed. This area was considered favorable for the development of vegetation for the highlands because the density of rock blocks was lower than in Deoksan Stony Slope, and the soil was exposed. Moreover, ash trees (Fraxinus rhynchophylla) and Korean maple trees (Acer pseudosieboldianum) that commonly appear in the valley areas were dominant here. It is probably due to the increased moisture content in the soil, which resulted from creating a depressive landform with a concave shape that is easy to collect rainwater as rock blocks in some areas fell and piled up in the lower region. In conclusion, the area, density of the rock blocks, and distribution pattern of rock block slopes would have affected the vegetation development and species composition in the debris slope landform.

Reduction of the Antigenicity of Whey Protein by Enzymatic Hydrolysis (효소가수분해에 의한 유청단백질의 항원성 저하)

  • Ha, Woel-Kyu;Juhn, Suk-Lak;Kim, Jung-Wan;Lee, Soo-Won;Lee, Jae-Young;Shon, Dong-Hwa
    • Korean Journal of Food Science and Technology
    • /
    • v.26 no.1
    • /
    • pp.74-80
    • /
    • 1994
  • As a preliminary study about the reduction of the antigenicity of whey protein isolate(WPI) by treatment of chymotrypsin, trypsin, pancreatin, and protease from Aspergillus oryzae, the properties and antigenicities of whey protein hydrolysates(WPH) were investigated. When degrees of hydrolysis (DH) were measured by use of trinitrobenzensulfonic acid(TNBS), the DH of the WPH treated by pancreatin or protease from Aspergillus oryzae$(5.05{\sim}11.47)$ were much higher than those of the tryptic or chymotryptic WPH$(15.67{\sim}20.20)$. And the pretreatments of heat$(75^{\circ}C)$, 20 min and/or pepsin resulted in higher DH of WPH, generally. When the molecular distributions of the WPH were determined by high performance size exclusion chromatography(HPSEC), the ratios of polypeptides with molecular weight more than 10kDa ranged from 12% to 36%, and the average molecular weights and the average peptide lengths of the WPH were $4,252{\sim}9,132$ dalton and $38{\sim}83$ amino acids, respectively. And there was no bitter taste in all of the WPH. Results of SDS-PAGE showed that most of intact native proteins were eliminated by the enzymatic hydrolysis but there were a few bands of peptides larger than 14.2 kDa in some WPH. When antigenicity was assayed by competitive inhibition enzyme-linked immunosorbent assay(cELISA), monovalent antigenicity of WPH to rabbit anti-WPI antiserum were lowered to $10^{-1.7}-10^{-4.9}$ times and less by the enzymatic hydrolysis. And the pretreatments of heat and pepsin resulted in the lowest antigenicicy within a group of enzymatic hydrolysis, especially in case of the pancreatic hydrolysate(PDP) whose antigenicity was found almost to be removed.

  • PDF