염지 온도와 기간이 삶은 돼지고기 등심의 이화학적 특성과 기호성에 미치는 영향

현재석,강희곤,김미숙,정인철,문윤희 한국축산식품학회 2003 한국축산식품학회지 Vol.23 No.1

식염농도 7%의 염지액을 이용하여 돼지고기 등심을 염지할 때에 염지온도와 기간이 염지육의 이화학적 특성과 기호성에 미치는 영향을 검토하였다. 열지온도 1$0^{\circ}C$에서 15일째에 염지육의 pH와 보수력이 현저히 저하되었다. 염지온도 1$0^{\circ}C$에서 염지액과 염지육 표면부위의 일반세균수는 12째에 현저히 많아졌으나 중심부위는 거의 검출되지 않았다. 임시 온도가 높을수록 염지기간에 관계없이 식염 침투가 빠르고 염지육 식염함량이 많아졌으며, 표면부위에 대한 중심분위의 식염함량 비율은 염지기간이 길수록 크게 나타났다. 염지육의 식염함량은 가열에 의하여 적어졌다. 염지 가열육의 짠맛과 풍미는 염지 초기에는 높은 온도에서, 후기에는 낮은 온도에서 우수하였다. 열지 가열육은 1$^{\circ}C$에서 12일, 5$^{\circ}C$에서 9일 염지하여 제조하면 기호성이 우수하였다. The effects of curing temperatures(1, 5 and 10$^{\circ}C$) and times on the chemical properties and palatability of cured pork loins which were cured in the 7% curing solution were investigated. The pork loins cured at 10$^{\circ}C$ curing temperature showed the decreased level of pH and water holding capacity up to 15 days of curing time. The growth of bacteria in the curing solution and surface region of cured loins, cured at 10$^{\circ}C$ were rapid after 12 days of curing. However, bacteria were not detected(<0.05${\times}$10$^2$ CFU/g) in the central region of cured loin until 15 days of curing. The penetration of salt into the central region of cured loins was faster at 10$^{\circ}C$ curing temperature than at lower curing temperatures for all curing times. The difference of salt contents between surface and central regions in the cured loins was less at higher temperature than at lower temperatures, and the difference decreased in boiling process for all curing times. The color fixation of the cured boiled loins was better at 5 and 10$^{\circ}C$ curing temperatures than at 1$^{\circ}C$. The sensory scores for saltiness and flavor of the cured boiled pork loins were higher at higher temperature than at lower temperatures until 9∼12 days of curing. Palatable cured boiled pork loins could be produced under the curing solution at low temperatures of 1 and 5$^{\circ}C$ for 12 and 9 days, respectively.

버어리종 잎담배 건조 환경 개선을 위한 건조실 개발 (I. 건조기간중의 미기상 변화)

차광호,장수원,양진철,오경환,신승구,조천준,Cha, Kwang-Ho,Jang, Soo-Won,Yang, Jin-Chul,Oh, Kyoung-Hwan,Shin, Seung-Ku,Jo, Chun-Joon 한국연초학회 2007 한국연초학회지 Vol.29 No.2

This study was carried out to investigate the changes of curing condition on microclimate of temperature, relative humidity during curing process of burley tobacco leaves. The developed facility, ridge opening type was designed to open the central top roof. The air-cured variety, (N. tabacum cv KB111) was normally grown at the Eumseong tobacco experimental station in 2007. Mean daily temperature of $3^{\circ}C$ in ridge opening type curing facility was lower than that of conventional, whereas mean daily relative humidity of 12.6 % RH was lower in conventional curing facility for the entire stage of curing. The frequency distribution of optimal air temperature at daytime was higher 37.5 % in ridge opening type curing facility than that of conventional, while that of optimal relative humidity was lower 8.2 %. In the ridge opening type curing facility, the excessive drying leaves were low, however the price per kilogram was high. These results suggest that the new developed curing facility may be applied to improved microclimate inside the curing facility for curing burley.

Effects of subsequent curing on chloride resistance and microstructure of steam-cured mortar

Hu, Yuquan,Hu, Shaowei,Yang, Bokai,Wang, Siyao Techno-Press 2020 Advances in concrete construction Vol.9 No.5

The influence of subsequent curing on the performance of fly ash contained mortar under steam curing was studied. Mortar samples incorporated with different content (0%, 20%, 50% and 70%) of Class F fly ash under five typical subsequent curing conditions, including standard curing (ZS), water curing(ZW) under 25℃, oven-dry curing (ZD) under 60℃, frozen curing (ZF) under -10℃, and nature curing (ZN) exposed to outdoor environment were implemented. The unsteady chloride diffusion coefficient was measured by rapid chloride migration test (RCM) to analyze the influence of subsequent curing condition on the resistance to chloride penetration of fly ash contained mortar under steam curing. The compressive strength was measured to analyze the mechanical properties. Furthermore, the open porosity, mercury intrusion porosimetry (MIP), x-ray diffraction (XRD) and thermogravimetric analysis (TGA) were examined to investigate the pore characteristics and phase composition of mortar. The results indicate that the resistance to chloride ingress and compressive strength of steam-cured mortar decline with the increase of fly ash incorporated, regardless of the subsequent curing condition. Compared to ZS, ZD and ZF lead to poor resistance to chloride penetration, while ZW and ZN show better performance. Interestingly, under different fly ash contents, the declining order of compressive strength remains ZS>ZW>ZN>ZD>ZF. When the fly ash content is blow 50%, the open porosity grows with increase of fly ash, regardless of the curing conditions are diverse. However, if the replacement amount of fly ash exceeds a certain high proportion (70%), the value of open porosity tends to decrease. Moreover, the main phase composition of the mortar hydration products is similar under different curing conditions, but the declining order of the C-S-H gels and ettringite content is ZS>ZD>ZF. The addition of fly ash could increase the amount of harmless pores at early age.

황색종 Bulk건조시 송풍량 조절에 따른 건조엽의 물리성 변화

이철환,진정의,한철수 한국연초학회 1999 한국연초학회지 Vol.21 No.1

In recent years, the line of increase in policy on tobacco production triggered a rise in the loading volume per bulk curing barn, and manufacturers boosted the output of their blowers in order to prevent dirty leaves in the process of curing. for this reason, we studied the effect of the reducing air flow in bulk curing chamber from the color fixing stage to the stem drying stage of flue curing process on physical properties of cured leaves. The control of air flow was composed of the reducing air velocity of blower by means of a voltage regulator (slidac), and condition before color fixing stage was all the same with the conventional curing method. As a result, an effectiveness of improvement in the physical properties of cured leaves were observed. The leaves cured by this method were somewhat orange in color of upper stalk position, better bodied, and less brittle compared with the leaves produced by conventional curing. However, the leaves cured by this method had a little sharpness and harshness. As to the physical properties, there was decreased in occurrence of flat leaves than that of conventional ones. On the other hand, in case of reducing air flow during the curing process, increase of price per kg reached to about 5 % compared with those of conventional curing method.

Effect of Steam Curing on Concrete Piles with Silica Fume

N. Yazdani,F. ASCE, M. Filsaime,T. Manzur 한국콘크리트학회 2010 International Journal of Concrete Structures and M Vol.4 No.1

Silica fume is a common addition to high performance concrete mix designs. The use of silica fume in concrete leads to increased water demand. For this reason, Florida Department of Transportation (FDOT) allows only a 72-hour continuous moist cure process for concrete containing silica fume. Accelerated curing has been shown to be effective in producing high-performance characteristics at early ages in silica-fume concrete. However, the heat greatly increases the moisture loss from exposed surfaces, which may cause shrinkage problems. An experimental study was undertaken to determine the feasibility of steam curing of FDOT concrete with silica fume in order to reduce precast turnaround time. Various steam curing durations were utilized with full-scale precast prestressed pile specimens. The concrete compressive strength and shrinkage were determined for various durations of steam curing. Results indicate that steam cured silica fume concrete met all FDOT requirements for the 12, 18 and 24 hours of curing periods. No shrinkage cracking was observed in any samples up to one year age. It was recommended that FDOT allow the 12 hour steam curing for concrete with silica fume.

이중경화법을 이용한 열개시제 및 광개시제가 배합된 황칠도료의 경화속도 촉진 및 물성향상 연구

황현득 ( Hyeon Deuk Hwang ),문제익 ( Je Ik Moon ),박초희 ( Cho Hee Park ),김현중 ( Hyun Joong Kim ),황백 ( Baik Hwang ) 한국목재공학회 2010 목재공학 Vol.38 No.4

한반도 남부 일대에서 자생하는 황칠나무(Dendropanax morbifera Lev.) 수액으로부터 추출한 천연 도료인 황칠도료(Korean Dendropanax lacquer)는 예로부터 귀중한 예술품이나 투구, 화살, 활 등의 전쟁도구를 찬란한 황금색으로 도장하는데 사용되어 왔다. 경화 후 황금색의 투명한 도막을 형성하여 우수한 색상특성을 지니고 있을 뿐만 아니라 내후성, 내수성, 내식성 등이 우수하여, 보호도장으로써도 훌륭한 가치를 지니고 있다. 그러나 이러한 많은 장점에도 불구하고, 현대적인 여러 적용분야에 사용되지 못하고 있는 이유는 황칠도료의 생산량이 적고, 이로 인하여 가격이 매우 고가이고, 장시간의 경화시간이 소요되는 문제도 큰 원인으로 작용하고 있다. 한편 황칠 내에 광중합이 가능한 conjugated diene을 포함한 모노머가 있으며, 이러한 모노머는 일광 조사 조건 등에 의하여 짧은 시간에 단단하고 황금색을 띠는 도막을 형성할 수 있음이 보고된 바가 있다. 따라서 본 연구에서는 전통적인 황칠도료의 경화방법을 개선하고 경화속도를 촉진하기 위하여, 열개시제를 도입하여 열경화를 촉진하는 방법과 열개시제 및 광개시제를 동시에 도입하고 이중경화(dual curing)에 의해서 경화속도를 촉진하고자 하였다. 이러한 경화 속도 및 경화 거동은 적외선분광분석기(FT-IR)을 이용하여 -C=C- 이중결합 특성피크의 변화를 관찰하거나, 진자경도계(pendulum hardness tester)를 이용하여 표면 경도의 변화를 관찰함으로써 평가하였다. 또한 강체진자물성측정기(RPT)에 spot UV curing 장비를 도입하여 이중경화에 의한 경화 속도 촉진을 평가하였다. 본 연구의 결과 열개시제에 의하여 열경화가 촉진될 수 있을 뿐만 아니라, 이중경화에 의하여 경화속도를 향상시킬 수 있음을 확인하였다. 또한 이러한 황칠도료 경화 속도 촉진 방법을 활용하여 전통적인 영역에만 사용되어온 황칠도료를 현대적인 여러 적용분야에도 확대하여 사용할 수 있는 가능성을 제시하였다. The Korean Dendropanax lacquer, made from a natural resinous sap from Dendropanax morbifera Lev., was used as a golden and transparent varnish for the traditional artifacts (armor suits, helmets, arrowheads, etc.) to make them be brilliant golden color. The cured film of the lacquer has excellent protective properties such as weatherability, water resistance, and anticorrosive. But, one of disadvantages is that takes a long time and much energy to fulfill curing of the lacquer. The chemical constituents of the lacquer contained conjugated diene compounds as the photopolymerizable monomers. These monomers easily polymerized in sunlight to form golden-colored, hard-coating films in a short time. Photooxidation may be one of the most important reactions in the chemistry of the lacquer. Although the Korean Dendropanax Lacquer should be dried to a thoroughly dry stage to achieve optimal film properties, curing with elevated temperatures may be required for the protracted curing time at atmospheric temperature. So we intended to accelerate the curing rate of the lacquer by dual curing of thermal and radiation curing. The effect of thermal initiator on the thermal curing reaction was evaluated by monitoring the changes in double bond peak with FT-IR. Then the curing rate of the lacquer blended with thermal initiator and photoinitiator together was measured during dual curing using a RPT with UV spot curing machine. Thermal initiator not only accelerated the curing rate but also improved the physical property. And the curing rate of the Korean Dendropanax lacquer was improved by dual curing method of thermal and UV curing. According to these results, the application area of the Korean Dendropanax lacquer could be expanded to surface coatings for electronic devices such as mobile phones or electronics.

버어리엽 건조과정에서 비휘발성 유기산, 지방산 및 폴리페놀화합물의 함량변화

김도연,배성국,이정일,지상운,김영회 한국연초학회 2000 한국연초학회지 Vol.22 No.2

This study was carried out to investigate the changes in composition of the non-volatile organic acid, fatty acid and polyphenolic compounds during air-curing in burley tobacco leaves, and the effect of curing methods on the contents in air-cured leaves. The air-cured variety, (Nicotiana tabacum cv KB108) was normally grown at the Chonju tobacco experiment station in 1998. Plants designated for the each curing methods were harvested on the same date, and the ripe leaves for primed curing were harvested at the tenth leaf position from the top on the stalk. The major compounds of non-volatile organic acid and fatty acid were malic, citric, oxalic, palmitic, and linolenic acid. The concentrations of malic acid, unsaturated fatty acids, chlorogenic acid and rutin in cured leaves were remarkably decreased during curing, while citric acid was increased. The changes of these compounds showed the similar pattern during both primed and stalk curing. In connection with curing methods, the contents of malic, linoleic and linolenic acid were higher in excessive cured leaves than those in primed cured or stalk cured leaves, while the content of citric acid was lower in excessive cured leaves than that in primed cured or stalk cured leaves.

Thermo-mechanical finite element simulation and validation of rubber curing process

Sittichai Limrungruengrat,Arisara Chaikittiratana,Sacharuck Pornpeerakeat,Tonkid Chantrasmi 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.6

Vulcanization, or curing, is a very important process in producing useful rubber products. The curing process takes place when heat is transferred to the rubber compounds inside a heated mold. The temperature distribution in the rubber significantly affects cure level distribution throughout the part. The problem of non-uniformity of cure level of the final product often occurs in a large rubber component, such as a tire or a rubber track, leading to poor quality and performance. The expansion of the rubber due to temperature increase and the rise of elastic modulus during the curing process lead to an increase in stress inside the mold, which can cause excessive mold deformation and the appropriate mold press force should be determined. This work’s aim was to develop a methodology for the analysis of the vulcanization process using a coupled thermo-mechanical finite element method to simulate a nonlinear heat transfer process coupled with curing kinetics and the evolution of thermal and mechanical properties. User subroutines UMATHT and UMAT were developed and implemented into the finite element package ABAQUS to evaluate the cure level distribution and stress developed inside the mold during curing. Experimental tests were carried out to study and evaluate the thermal, curing, and mechanical properties as dependent functions of temperature and cure level. A simple compression molding test was performed and the results were used to validate the simulated predictions. It is shown that the predictions of the temperature, cure level distribution in the rubber part and press force during curing process obtained from the developed finite element analysis are in the good agreement with the experimental data. Furthermore, the simulations with thermal and mechanical properties varying with temperature and cure level are closer to the measured data than one with constant properties.

버어리종 건조방법이 건엽의 품질에 미치는 영향

배성국,조천준,임해건,김요태 한국연초학회 1998 한국연초학회지 Vol.20 No.1

This study was conducted to obtain the basic information on the burley tobacco (Nicotiana tabacum L.) curing methods. The effects of the three kinds of curing methods on the dry weight losses during curing, chemical contents and physical properties of cured leaves, and organoleptic and smoking qualities were observed. The dry weight losses during curing was the highest in the stalk curing, and the lowest in the conventional priming. The longer the curing periods was, the more the loss of dry weight. The percent of the excessive dried leaves was high and the price per kilogram was low in the conventional priming. The chemical contents and the physical properties of the cured leaves in the conventional priming were similar to those of yellowing or browning stage of curing. But, the chemical contents and the physical properties of the cured leaves in the stalk curing were comparable to those of the air curing. The smoking quality was the best in the stalk curing.

버어리종 잎담배의 건조조건이 정유성분 조성에 미치는 영향

배성국,김도연,이윤환,김영회 한국연초학회 2002 한국연초학회지 Vol.24 No.2

This study was performed to investigate the influence of curing conditions on the composition of essential oil during curing process of burley tobacco leaves. The curing conditions were the primed curing in vinyl house (house-curing), air-curing barn (air-curing) and stalk-curing in conventional curing house (stalk-curing). Total 90 compounds are identified from the steam volatile oils of harvest and cured tobacco leaves by GC and GC-MS, respectively. The major components were neophytadiene, hexadecanoic acid, 3,8,13-duvatriene-1,5-diols, oxide-9-methylene-3,13-duvadienols, solanone, megastigma-4,6,8-trien-3-ones, phenylacetaldehyde, $\beta$-phenylethyl alcohol, indole, dihydroactinidiolide and phytol. The amount of alcoholic compounds was decreased more than approximately 50% in cured leaves without regard to the curing conditions. $\beta$-Phenylethyl alcohol and 3,8,13-duvatriene-1,5-diols were decreased more in air curing and stalk curing than in house curing. The amounts of phenylacetaldehyde, solanone, $\beta$-damascone, $\beta$ -damascenone, oxysolanone and megastigma-4,6,8-trien-3-ones as ketonic compounds, dihydroactinidiolide and indole as miscellaneous compounds in air-cured and stalk-cured tobacco leaves were 2 times higher than those in house-cured leaves, while esteric and acidic compounds were not changed largely in content by curing conditions.