• Title/Summary/Keyword: external heat method

Search Result 233, Processing Time 0.027 seconds

Weight Loss Prediction by Operating Conditions of CA Storage (CA저장고의 작동 환경에 따른 감모율 예측)

  • Park, Chun Wan;Park, Seok Ho;Kim, Jin Se;Choi, Dong Soo;Kim, Yong Hun;Lee, Su Jang
    • Food Engineering Progress
    • /
    • v.21 no.4
    • /
    • pp.312-317
    • /
    • 2017
  • Weight loss that influences quality and farmer incomes is affected by the storage environment of agricultural products. The interior of storage should be maintained at high humidity to prevent the weight loss of products which contain a lot of moisture. The research had constantly proceeded with change in the heat exchanger surface areas, humidity systems, and weight loss forecast to maintain high humidity within storage. Relative humidity that exerts an effect weight loss of crop is influenced by storage temperature, leak state, and volume of product. When weight loss is predicted, different conditions of these factors are derived. In case of CA storage, ways of forecasting the weight loss become easier compared to cold storage due to sealed storage with external environment during storage period. In this study, apples were stored in purge-type CA storage and weight loss has been predicted by using operating characteristics and environmental conditions. As a result, humidity variation in the storage fluctuates with the operation of the unit-cooler. Furthermore, unit-cooler operation factor is influenced by outside temperature and respiration heat. Prediction value of weight loss according to temperature and humidity has been most accurately predicted. Prediction value through defrosting water measured shows unit-cooler work quality. K-value needs verification to calculate the VPD method.

Development of Digital Solder Station Based on PID Controller (PID 제어기를 이용한 전기인두기의 온도 제어 시스템 개발)

  • Oh, Kab-Suk
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.11 no.3
    • /
    • pp.866-872
    • /
    • 2010
  • In this paper, we developed a digital soldering station based on PID controller, which supply stable power by controlling the current of heater of soldering iron. The proposed system designed PID controller to converge quickly to the set up temperature by user, and regain the lost of heat by external factors quickly. PID controller, designed by Ziegler-Nichols' tuning method, decides triac's trigger timing using setting temperature and present temperature to control the phase of AC 24V power that supply to the heater. Also, we give the function that shows present temperature and setting temperature of iron, and working time by graphic LCD. And during the rest time, we decided the power saving and extension of iron tip by dropping to the optimal temperature. Two experiments had implemented in $25^{\circ}C$ laboratory to confirm the performance of proposed method. The first experiment took 12sec, 13sec, 16sec, 18sec, reaching to $200^{\circ}C$, $300^{\circ}C$, $400^{\circ}C$, $480^{\circ}C$ respectively which result showed shorten of rising time than previous method. In the loading experiment of $300^{\circ}C$, $400^{\circ}C$, $480^{\circ}C$ steady state showed temperature drop of $3.8^{\circ}C$, $4.1^{\circ}C$, $4.5^{\circ}C$ which result showed the low temperature deviation than previous method.

Microbiological Hazard Analysis for HACCP System Application to Non Heat-Frozen Carrot Juice (비가열냉동 당근주스의 HACCP 시스템 적용을 위한 미생물학적 위해 분석)

  • Lee, Ung-Soo;Kwon, Sang-Chul
    • Journal of Food Hygiene and Safety
    • /
    • v.29 no.2
    • /
    • pp.79-84
    • /
    • 2014
  • This study has been performed for about 270 days at analyzing biologically hazardous factors in order to develop HACCP system for the non heat-frozen carrot juice. A process chart was prepared by manufacturing process of raw agricultural products of non heat-frozen carrot juice, which was contained water and packing material, storage, washing, cutting, extraction of the juice, internal packing, metal detection, external packing, storage and consignment (delivery). As a result of measuring Coliform group, Staphylococcus aureus, Salmonella spp., Bacillus cereus, Listeria Monocytogenes, Enterohemorrhagic E. coli before and after washing raw carrot, Standard plate count was $4.7{\times}10^4CFU/g$ before washing but it was $1.2{\times}10^2CFU/g$ detected after washing. As a result of testing airborne bacteria (Standard plate count, Coliform group, Yeast and Fungal) depending on each workplace, number of microorganism of in packaging room, shower room and juice extraction room was detected to be 10 CFU/Plate, 60 CFU/Plate, 20 CFU/Plate, respectively. As a result of testing palm condition of workers, as number of Standard plate count, Coliform group and Staphylococcus aureus was represented to be high as $6{\times}10^4CFU/cm^2$, $0CFU/cm^2$ and $0CFU/cm^2$, respectively, an education and training for individual sanitation control was considered to be required. As a result of inspecting surface pollution level of manufacturing facility and devices, Coliform group was not detected in all the specimen but Standard plate count was most dominantly detected in scouring kier, scouring kier tray, cooling tank, grinding extractor, storage tank and packaging machine-nozzle as $8.00{\times}10CFU/cm^2$, $3.0{\times}10CFU/cm^2$, $4.3{\times}10^2CFU/cm^2$, $7.5{\times}10^2CFU/cm^2$, $6.0{\times}10CFU/cm^2$, $8.5{\times}10^2CFU/cm^2$ respectively. As a result of analyzing above hazardous factors, processing process of ultraviolet ray sterilizing where pathogenic bacteria may be prevented, reduced or removed is required to be controlled by CCP-B (Biological) and critical level (critical control point) was set at flow speed is 4L/min. Therefore, it is considered that thorough HACCP control plan including control criteria (point) of seasoning fluid processing process, countermeasures in case of its deviation, its verification method, education/training and record control would be required.

A Study on the Prediction of HLW Temperature from Natural Ventilation Quantity using CFD (전산유체학을 이용한 고준위 방사성 폐기물 처분장의 자연환기량에 의한 온도예측)

  • Roh, Jang-Hoon;Yu, Yeong-Seok;Jang, Seung-Hyun;Park, Seon-Oh;Kim, Jin
    • Tunnel and Underground Space
    • /
    • v.22 no.6
    • /
    • pp.429-437
    • /
    • 2012
  • This study predicted temperature in the disposal tunnels using computational fluid dynamics based on natural ventilation quantity that comes from high altitude and temperature differences that are the characteristics of high level waste repository. The result of the previous study that evaluated quantitatively natural ventilation quantity using a hydrostatic method and CFD shows that significant natural ventilation quantity is generated. From the result, this study performed the prediction of temperature in disposal tunnels by natural ventilation quantity by the caloric values of the wastes, at both deep geological repository and surface repository. The result of analysis shows that deep geological repository is effective for thermal control in the disposal tunnels due to heat transfer to rock and the generation of sufficient natural ventilation quantity, while surface repository was detrimental to thermal control, because surface repository was strongly affected by external temperature, and could not generate sufficient natural ventilation quantity. Moreover, this study found that in the case of deep geological repository with a depth of 200 m, the heatof about $10^{\circ}C$ was transferred to the depth of 500 m. Thus, it is considered that if the high level waste repository scheduled to be built in the country is designed placing an emphasis on thermal control, deep geological repository rather than surface repository is more appropriate.

The Analysis of Elasto-Plastic Thermal Stresses for Welding Part in Double Capstan Drum (더블 캡스턴 드럼의 용접부에 대한 탄소성 열응력해석)

  • 김옥삼
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.36 no.4
    • /
    • pp.329-336
    • /
    • 2000
  • Welding is a important technological method in mechanical engineering. $CO_2$MAG(metal active gas) welding means that metal part in double capstan drum for the inshore and costal vessels are joined by melting(with or without a filler material) or that new material is added to a metal part by melting. The thermal stresses appear due to a non-uniform temperature field, inhomogeneous material properties, external restraint and volume changes during phase transformations. In this study analysis the elasto-plastic thermal stresses distribution of welding part in double capstan drum for the inshore and costal vessels using finite element method (FBM). Therefore it calculates the numerical value that can be applied to the optimum design of welding parts and the shapes. The significant results obtained in this study are summarized as fellows. At early stage of the cooling after welding process, the abrupt thermal stresses gradient has been shown in the vicinity of welding part. In the thermal stresses analysis due to temperature gradient and heat shocking maximum stress was occurred of welding part and stresses were distributed from 54MPa~48MPa.

  • PDF

Effect of Thermal Treatments on Flavonoid Contents in Domestic Soybeans (국내산 대두(Glycine max. Merr)자원의 플라보노이드 대사체 동정 및 열처리 효과)

  • Shin, Jae-Hyeong;Kim, Heon-Woong;Lee, Min-Ki;Jang, Ga-Hee;Lee, Sung-Hyen;Jang, Hwan-Hee;Hwang, Yu-Jin;Park, Keum-Yong;Song, Beom-Heon;Kim, Jung-Bong
    • Korean Journal of Environmental Agriculture
    • /
    • v.34 no.2
    • /
    • pp.105-110
    • /
    • 2015
  • BACKGROUND: Soy isoflavones, structurally similar to endogenous estrogens, may affect human body through both hormonally mediated and non-hormonally related mechanisms. Heat processing could change chemical compositions. The effects of different thermal processes, boiling and HTHP(high temperature and high pressure) on the composition of isoflavone compounds and total amount of domestic soybeans were investigated in this study. METHOD AND RESULTS: Three different kinds of soybean samples were collected from RDA-Genebank. The samples were extracted using methanol, distilled water, and formic acid based solvent. Also the same solvents were used for mobile phase in UPLC/ToF/MS. All of the isoflavone compounds were analyzed based on the aglycone type of external standard for quantification. The standard calibration curve presented linearity with the correlation coefficient R2 > 0.98, analysed from 1 to 50 ppm concentration. The total isoflavone contents does not change by treatment within the same breed. While "boiling" and "HTHP" processes tend to increase the contents of aglycone and ${beta}$-glucosides, "fresh" soybeans retained the high concentration of malonylglucosides. CONCLUSION: These results have to be considered while developing an effective functional food, from the health while point of view using soybeans.

Hair Strengthening Effect of Silane Coupling and Carbodiimide Chemistry (카르보디이미드 반응과 실란 커플링을 이용한 모발강화 효과)

  • Son, Seong Kil;Choi, Wonkyung;Lim, Byung Tack;Song, Sang-hun;Kang, Nae Kyu
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.44 no.2
    • /
    • pp.133-139
    • /
    • 2018
  • Chemically damaged hair is vulnerable to external stimuli in daily life due to the weakened physical properties of the hair strand itself. The purpose of this work was to determine whether chemical conjugation between hair keratin proteins restores tensile strength and thus results inpreventing further deterioration under repeated combing. A model damaged hair tress was produced by a typical perm-process. Then, it was internally crosslinked by the bifunctional crosslinker (3-aminopropyl)triethoxysilane (APTES), via both silane coupling and carbodiimide chemistry. Physical properties, including tensile strength, Young's modulus, and plateau stress, were measured to verify the effect of internal crosslinking, and the existence of crosslinking was verified by Fourier transform infrared (FT-IR) spectroscopy. The degrees of hair breakage and split ends were evaluated by repeated combing-drying tests. Physical properties of chemically damaged hair were restored by internal crosslinking. Successful crosslinking of APTES via both silane coupling and carbodiimide chemistry was verified by FT-IR spectra. Prevention of breakage and split ends after repeated combing with heat was observed. Human hair can be weakened by chemical damage including perm-processing, so restoring such properties is a major issue in the hair care industry. This work shows that internal crosslinking of damaged hair via chemical conjugation would be a potent method to restore the healthy hair.

Development of Eco-friendly Combustion Process for Waste 2,4,6-trinitrotoluene (폐 2,4,6-trinitrotoluene의 환경 친화적 연소처리공정 개발)

  • Kim, Tae Ho;An, Il Ho;Kim, Jong Min
    • Clean Technology
    • /
    • v.27 no.3
    • /
    • pp.247-254
    • /
    • 2021
  • In this study, an eco-friendly combustion process of waste 2,4,6-trinitrotoluene (TNT: 2,4,6-trinitrotoluene) was developed, and fundamental data for the quantity of the organic matter in the final combustion residues is presented. Because complete combustion of TNT is not possible theoretically, the combustion process was optimized to reduce organic matter content in the combustion residue by performing measures such as heating time changes, addition of propellant material, and after treatment using a high-temp electrical furnace. From the results, it was confirmed that the organic matter content in the residue could be decreased to 7 ~ 10% with each method. The quantity of the organic matter could be minimized by optimizing the combustion conditions of the process. With only a combustion time increase, the amount of organic matter in the combustion residues was measured at about 9 wt%. The environmental friendliness of the final exhaust gas was also confirmed by real time gas component analyses. In addition, the organic contents could be reduced by a further 2 wt% by applying an additional heat treatment using an external electric furnace after the first incineration treatment. In the combustion process of propellant added waste TNT, it was found that various TNT wastes could be treated using the same eco-friendly protocols because the organic content in the residue decreased in accordance with the amount of propellant. The amount of the organic matter content produced by all these methods fulfilled the requirements under the Waste Management Act.

Calculation of Crack Width of the Top Flange of PSC Box Girder Bridge Considering Restraint Drying Shrinkage (구속 건조수축을 고려한 PSC BOX 거더교 상부플랜지 균열폭 산정)

  • Young-Ho Ku;Sang-Mook Han
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.27 no.3
    • /
    • pp.30-37
    • /
    • 2023
  • The PSCB girder bridge is a closed cross-section in which the top and bottom flanges and the web are integrated, and the structural characteristics are generally different from the bridges in which the girder and the floor plate are separated, so a maintenance plan that reflects the characteristics of the PSCB girder bridge is required. As a result of analyzing damage types by collecting detailed safety diagnosis reports of highway PSCB girder bridges, most of the deterioration and damage occurring during use is concentrated on the top flange. In particular, cracks in the bridge direction on the underside of the top flange occurred in about 70 % of the PSCB girder bridges to be analyzed, and these cracks were judged to be caused by indirect loads such as heat of hydration and drying shrinkage rather than structural cracks caused by external loads. In order to improve durability and reduce maintenance costs of PSCB girder bridges in use, it is necessary to control restraint drying shrinkage cracks from the design stage. Therefore, in this paper, the cracks caused by drying shrinkage under restraint, which is the main cause of cracks under the flanges of the top part of the PSCB girder bridge, were directly calculated using the Gilbert Model, and the influencing factors such as the amount of reinforcing bars, diameter and spacing of reinforcing bars were analyzed. As a result of the analysis, it was found that the crack width caused by restraint drying shrinkage exceeded the allowable crack width of 0.2 mm for reinforcing bars with a reinforcing bar ratio of 0.01 or less based on the H16 reinforcing bar and a reinforcing bar with a diameter greater than H19 based on the reinforcing bar ratio of 0.01. Finally, based on the results of the crack width review, a method for controlling the crack width of the top flange of the PSCB girder bridge was proposed.

A Study of the Case Record on Dyspnea and Wheezing Asthma Recorded in Xu Ming Yi Lei An ((${\ll}$속명의류안(續名醫類案)${\gg}$에 기재(記載)된 천(喘) 및 효천(哮喘)에 관(關)한 의안(醫案) 연구(硏究))

  • Lee, Ju-Il
    • Herbal Formula Science
    • /
    • v.15 no.1
    • /
    • pp.49-105
    • /
    • 2007
  • Objectives : Select and analyze the case record of dyspnea and wheezing asthma recorded in Xu Ming Yi Lei An that is the most abundant and wide in contents in existing case records that are systematic, comprehending relatively modern Traditional Chinese Medicine to secure more deep and objective basis of Traditional Chinese Medicine approach for dyspnea and wheezing asthma to analyze and review possibility for clinical application in this study. Methods: The study was conducted with the case records of dyspnea and wheezing asthma in whole Xu Ming Yi Lei An. Pattern identify and classify selected case records and again classified with deficiency syndrome and excess syndrome. Also analyzed prescriptions and herbs used in the case records. Nature of herbs and properties and flavors that were used in the case records were classified and frequency of each nature of herbs were analyzed. Applicable case records were interpreted and suggested prescriptions, pulse feelings, pattern classification were analyzed and described. Results : Among the 5254 case records stated on the complete collection, it is researched that there are 63 case records for the symptom complex of dyspnea as 1.2% of the whole case records, and the case records on the symptom complex of wheezing asthma are 14 as the 0.27% of the total examples. 63 case record examples related with symptom complex of dyspnea were pattern identified and classified. As a result, deficiency syndrome of the Kidney(33 %), deficiency syndrome of the Spleen(26.0%), Wind-Cold(12.3%), phlegm turbidity(12.3%), Heat in the Lung(8.2%), asthenia of the Lung(8.2%) were investigated as above order. 14 case record examples related with wheezing asthma were pattern identified and classified. As a result, phlegm-Heat(26.3%), upper excess and lower deficiency(26.3%), external affections Wind-Cold(15.8%), Dampness-phlegm(10.5%), Lung asthenia(10.5%), Cold phlegm(5.3%), mutual deficiency and detriment of Heart and Kidneys(5.3%) were investigated as above order. Symptom complex of dyspnea has 67.1% of deficiency syndrome, 32.9% of excess syndrome resulting more deficiency syndrome than excess syndrome. Symptom complex of wheezing asthma has 42.1 % of deficiency syndrome and 57.9% of excess syndrome resulting more excess syndrome than deficiency syndrome. In case of symptom complex of dyspnea prescription used in the case record, the order of frequency is as following. Palmijihwang-tang, Bojung-ikgitang, Yungmijihwang-tang, Ijintang, Sojaganggitang, Igongsan. In case of symptom complex of wheezing asthma prescription in the case record, Yungmijihwang-tang, Ohotang, Dodamtang were mostly used. Herbs used in case records of symptom complex of dyspnea are Ginseng Radix, Poria, Glycyrrhizae Radix, Aconiti Iateralis Preparata Radix, Atractylodis Macrocephalae Rhizoma, Dioscoreae Rhizoma, Angelicae Gigantis Radix, Rehmanniae Radix Preparat, Pinelliae Rhizoma, Zingiberis Rhizoma Recens are mostly used. Nature of herb properties used for symptom complex of dyspnea and symptom complex of wheezing asthma are herbs that are warm properties. When the symptom complex of dyspnea and the symptom complex of wheezing asthma were treated. if the patient felt tenderness at Pyesu, doctors conducted pricking blood around the opposite Pyesu or Sipseon acupoint. when the patient didn't have tenderness at Pyesu by soft press, pricking blood was performed both sidees, right and left Pyesu. In case of the treatment of symptom complex of dyspnea and symptom complex of wheezing asthma, when they got treatment, when the symptom complex of disease is severe, a doctor cauterized the opposite Pyesu while the other Pyesu felt tenderness, and decided how the above treatment is performed whether the degree of the symptom compolex of disease is severe or not. In case of the treatment of symptom complex of dyspnea and symptom complex of wheezing asthma, if the person felt tenderness at Pyesu and is caught by the Wind-Cold pathogen, slight acupuncture is treated at relevant Pyesu with Fire needling. When patient with symptom complex of dyspnea and symptom complex of wheezing asthma cannot hawk sputum up from the oral and laryngopharynx, suction method is treated. Conclusion : With this study, actual traditional and clinical pattern identification form and characteristics of symptom complex of dyspnea and symptom complex of wheezing asthma were recognized. Modern case report utilizing in clinical application need to be secured and an incurable disease asthma need to be diagnosed and improvement for treatments have to be searched through other case records.

  • PDF