• 한국축산식품학회지
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• 제35권4호
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• pp.441-448
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• 2015

Blanching beef for use in home meal replacements (HMR) is an important process that determines the final quality of the beef after the cooking process. Thermal pretreatment also minimizes the change in quality during the main cooking process or storage. In this study, beef samples were washed and sliced, then treated by immersion in boiling water (1-10 min), steaming (1-10 min), or pan-frying in oil (30-240 s). The color after each thermal treatment showed higher L* and b* values and lower a* values compared with the raw beef, except for the pan-frying thermal treatment. The total color difference (∆E) and pH value were significantly increased by panfrying (p<0.05). There was no significant difference in the shear force of the beef samples, except for the sample pan-fried for 210 s. The nutritional content of beef was measured as the moisture, protein, fat, and ash contents, which were 69.96, 16.64, 3.49, and 1.13%, respectively, in raw beef. After thermal treatment, the crude protein and fat contents were increased, whereas the moisture and ash contents decreased. The mineral content, including Na, Mg, Fe, and Ca was highest after pan-frying. The heat treatment decreased microorganisms in all the samples. The total bacteria count in raw beef was 4.5-4.7 Log CFU/g, whereas the bacteria count decreased to 2.2-2.8 Log CFU/g after blanching. Thermophilic bacteria, coliform, mold, and yeast not detected in any thermally treated sample.

• 한국가축번식학회지
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• 제19권1호
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• pp.43-48
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• 1995

The purpose of this study was to examine the suvival rates of cryopreserved porcine embryos collected on Day 6 (Day 0=onset of estrus) with various cryprotectants. Eighty two embryos at different stages, ranged from expanded blastocyst to hatched blastocyst, were allocated to 6 experimental groups in different combinations of cryoprotectants glycerol, egg yolk and/or trehalose. Porcine embryos were cryopreserved using conventinal slow freezing precedures. The embryos were equilibrated with one of the freezing solutions, cooled from 25 to -7$^{\circ}C$ at 1$^{\circ}C$/min, seeded at -7$^{\circ}C$ frozen to -36$^{\circ}C$ at 0.5$^{\circ}C$/min, and then plunged into liquid nitrogen. The frozen embryos were thawed by immersion in 37$^{\circ}C$ water and the cryoprotectants were removed by dilution with 0.5M sucrose solution. Embryonic survival was estimated from the normal development of embryos for 12, 24 and 48hrs culture. Then the embryos were stained and their cell nuclei was counted. The survival rates of morphological embryos were significantly higher in group I (10% glycerol) or group IV (10% glycerol＋10% egg yolk＋0.5M trehalose) than those in other groups, although the nuclei number was quite higher in embryos treated with 10% glycerol and 0.25M trehalose at expended blastocyst. However, hatched blastocysts showed higher viability and nuclei number treated with either egg york or trehalose, but the survival rates after 48hrs of culture were quite low. These results indicate that egg yolk and trehalos as a supplement to freezing solutions can be useful to the cryopreservation ofn porcine embryos.

• 한국식품위생안전성학회지
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• 제9권3호
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• pp.175-184
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• 1994

This was performed to investigate the antiulcer effects of Aloe vera on the stomach ulcer induced by restraint and water-immersion stress in rats. For this experiment, 60 male Sprague-Dawley strain were used. The experimental groups were divided into five: a control(CA) and 4 aloe treatment groups. Each dose of aloe was 50 mg/kg BW(AA), 100mg/kg BW(AB), 200 mg/kg BW(AC), and 400 mg/kg BW(AD). The rats were allocated to each group by 12 and observed for 4 weeks. The results are as following. 1. The stomach surface pH in each group showed no significant difference, byt the values of aloe treatment groups were higher than the value of the control group. 2. The gastric wall mucus was significantly increased in all aloe treatment groups(p<0.05) compared with the control group. Especially in AC and AD group the differences were higher(p<0.01). 3. At shear rate rate 11.25, 45.0, 90.0, 225.0 sec-1, whole blood viscosity and plasma viscosity were measured. Most of the values of aloe treatment groups were significantly low compared with those of the control group(P<0.05). 4. The ulcer index of aloe treatment groups were significantly low campared with control group(p<0.05). Especially in AC and AD group the differences were more significant(p<0.01). 5. Less severe ulcers were observed in AA and AB group than in the control group. Tissues of AC and AD group had only slight ulcers and necrosis of tissue was not observed in these groups. Especially in AD group, there was more mucus than other groups and it seemed that alove vera stimulated the epithelial regeneration. From the results of this study, it can be concluded that the oral administration of Alove vera results in protection of stomach ulcer by stimulating the secretion of gastric mucus and the circulation of blood.

• 한국재료학회지
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• 제22권3호
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• pp.155-158
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• 2012

In this work, AlON-$Al_2O_3$ coatings were prepared on Al2021 alloy by the electrolytic plasma processing (EPP) method. The experimental electrolytes include: 2 g/l NaOH as the electrolytic conductive agent, 10 g/l $Na_2AlO_2$ as the alumina formative agent, and 0.5 g/l $NaNO_2$, $NaNO_3$, and $NH_4NO_3$ as the nitride inducing agents. The effects of different nitrogen inducing agents were studied by a combined compositional and structural analyses of the ceramic coatings carried out by Xray diffractometry (XRD) and scanning electron microscopy (SEM) for the specimens EPP-treated at room temperature for 15 min under a hybrid voltage of 260 DC along with an AC 50 Hz power supply (200 V). Microhardness tests and wear tests were carried out to correlate the evolution of the microstructure and the resulting mechanical properties. Potentiodynamic polarizations and immersion corrosion tests were carried out in 3.5wt% NaCl water solutions under static conditions in order to evaluate the corrosion behavior of the coated samples. The results demonstrate that $NaNO_2$ is proven to be a good nitrogen inducing agent to produce high quality AlON-$Al_2O_3$ ceramic coatings.

• Applied Biological Chemistry
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• 제46권1호
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• pp.12-15
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• 2003

클로렐라를 첨가하여 기능성 두부를 제조함에 있어 클로렐라의 첨가량이 두부의 품질에 미치는 영향을 조사하였다. 건조 대두를 기준으로 클로렐라를 0.5-2.0% 첨가하여 제조한 두부의 수율, 물성, 색도, 저장성 및 관능적인 특성을 클로렐라를 첨가하지 않고 제조한 일반두부와 비교하였다. 수율은 클로렐라를 1% 첨가한 경우 일반두부에 비하여 10% 이상 향상되었다. 클로렐라를 첨가함으로써 두부의 물성 중 견고성, 검성과 씹힘성이 증가하였으며, 색도는 L값, a값, b값 모두 첨가량에 비례하여 감소하였다. 관능적 특성은 조직감 이외의 항목에서는 일반두부와 통계적으로 유의적인 차이가 얼었다. 제조한 두부를 $15^{\circ}C$로 보관하면서 pH와 총균수의 변화를 측정한 결과 클로렐라를 0.5-1.0% 첨가한 두부에서 pH하락과 미생물 생육이 효율적으로 지연되었다.

• 에너지공학
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• 제13권2호
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• pp.93-100
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• 2004

간접법을 이용한 표면오염도 측정 시 시료채취와 동시에 방사선 검출이 가능한 스메어 매체를 제조하고 성능을 평가하였다. 스메어 매체는 무기섬광체를 고분자 막에 함침시킨 것으로서, 용매로는 디메틸포름아마이드(DMF)와 메틸렌클로라이드(MC) 그리고 고분자 소재로서 폴리설폰(PSF)을 사용하였고, 무기섬광체는 CAYS(cerium activated yttrium silicate)를 사용하였다. 함침막은 단일 및 이중구조로 제조하였고, 물. 메타놀 등 비용매성 욕조에 침지하거나 용매 증발을 통하여 고형화하여 특성을 비교하였다. 방사선과의 상호작용에 의하여 무기섬광물질 함침막으로부터 방출되는 광자의 계측은 광전증배관과 고전압원, 증폭기. 계수기로 구성된 원형계수기를 사용하였다. $^{14}$ C표면오염에 대해 무기섬광 함침막을 이용해 얻은 계수율을 통상의 저준위 알파/베타 계수기로 얻은 결과와 비교할 때 상대 감도가 약 50%로 나타났다. 또한, 계수효율이 상대적으로 낮았지만 저에너지 베타선 방출핵종인 $^3$H표면오염도측정이 가능하다는 것을 확인하였다.

• Restorative Dentistry and Endodontics
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• 제16권2호
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• pp.18-32
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• 1991

The purpose of this study was to observe characteristic properties of amalgam through the polarization curves and SEM images from 4 type amalgams (Amalcap, Shofu spherical. Dispersalloy and Tytin) with 3 different surface finish procedures (polishing, burnishing and carving) by using the potentiostats (EG & GPARC) and SEM (Jeol JSM-35). After each amalgam alloy and Hg was triturated as the direction of the manufacturer by means of mechanical amalgamator (Samki), the triturated mass was inserted into the cylndrical metal mold which was 12 mm in diameter and 10 mm in height and was pressed with $100kg/cm^2$. 4 specimens of each type amalgam were burnished with egg burnisher and another 4 specimens of each type amalgam were carved with Hollenback carver. Above 8 specimens and remaining untreated 4 specimens were stored at room temperature for about 7 days. Untreated 4 specimens of each type amalgam were polished with abrasive papers (Deer) from #400 to #1200 and finally on the polishing cloth with $0.5{\mu}m$ and $0.06{\mu}m$ $Al_2O_3 $ powder suspended water. Anodic polarization measurements was employed to compare the corrosion behaviours of the amalgams in 0.9% saline solution at $37^{\circ}C$. The open circuit potential was determined after 30 minutes immersion of specimen in electrolyte. The scan rate was 1 mV/sec and the surface area of amalgam exposed to the solution was $0.64cm^2$ for each specimen. All the potentials reported are with respect to a saturated calomel electrode (SCE). SEM images of each specimen were taken after + 800 mV (SCE) polarization. The results were as follows: 1. The corrosion potential of high copper amalgam was more anodic than that of low copper amalgam. 2. The polished amalgam were more resistant to corrosion than any other burnished and carved amalgam. 3. In the case of polishing, current density of high copper amalgam was lower than that of low copper amalgam.

• 한국양식학회지
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• 제15권1호
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• pp.23-29
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• 2002

기수재첩의 인공 종묘생산 기술개발의 일환으로 산란기 조사, 산란유발, 난 발생 및 유생의 발달 과정을 관찰 한 결과를 요약하면 다음과 같다. 기수재첩의 산란기는 7월 하순부터 9월 하순가지이며, 주 산란기는 8월 초순부터 9월 중순으로 나타났다. 산란유발은 자외선 조사 자극과 생식소절개 방법으로는 반응이 전혀 없었다. 3$\textperthousand$ 해수의 온도 자극에서는 8월하순에 90.0%, 9월에 75.0%의 높은 반응률을 보였다. NH$_4$OH용액을 3$\textperthousand$ 해수에 첨가하는 자극은 1/1000∼3/1000 N에서 15∼45%의 반응률을 보였다. 기수재첩의 수정난은 직경 86${\pm}$3 um의 구형이다. 수정난의 발생은 23.0∼24.5$^{\circ}C$에서 2시간 후 4세포기로 되고, 15시간이 지나면 담륜자 유생 (trochophore larvae),수정 후 2일째에는 D상 유생, 9일째에는 각정기로 성장하였다. 수정 16일째에는 성숙 유생으로 성장하여 저서 생활을 시작하였다.

• 한국결정성장학회지
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• 제17권2호
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• pp.75-81
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• 2007

[ $UO_2$ ] 소결체와 $U_3O_8$종자를 5wt% 첨가한 $UO_2$ 소결체의 치밀화 과정 및 입자성장 양상을 소결 온도 및 시간을 변수로 하여 분석하였다. $UO_2$ 성형체와 5wt% $U_3O_8$ 종자 첨가 성형체를 수소분위기에서 $1300^{\circ}C$에서 $1700^{\circ}C$로 온도를 올려가며 0시간에서 4시간 소결하여 밀도와 입자크기를 측정하였다. $1300^{\circ}C$까지는 종자 첨가에 상관없이 거의 같은 밀도를 가졌지만 온도가 올라가면서 종자 첨가 소결체의 치밀화가 저하되었다가 $1700^{\circ}C$ 근처에서 거의 비슷한 밀도를 가지게 된다. 입자성장의 경우, $1600^{\circ}C$에서는 종자 입자를 제외하면 기지상의 입자 크기는 거의 비슷하지만 $1700^{\circ}C$ 이후에서는 종자첨가 $UO_2$ 소결체의 입자성장이 종자가 첨가되지 않을 경우에 비하여 2배 이상 빠르게 진행되었다.

• 한국안전학회지
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• 제32권6호
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• pp.54-60
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• 2017

A railway rail will be corroded by the repetitive sea wind and fog in the splash and tidal zone such as Youngjong grand bridge. And these rusts of rail could be increased by increasing service period, and it frequently occurred the safety accidents or disorders in electrical problem. In this study, the sacrificial anode cathodic protection method was proposed as a measures for reducing the corrosion of the railway rails in the oceanic climate conditions. As the results of immersion test using the salt water during four months, the sacrificial anode cathodic protection method using the aluminum anode(Al-anode) was evaluated that a distinct effect on corrosion reduction in the rails. Therefore the sacrificial anode cathodic protection method was experimentally proven that a disorders in aspects electric and signal of railway operation condition such as direct fixation track system in Youngjong grand bridge could be prevented by reducing rust falling from the rail. In addition, the installation conditions of the anodes directly affect the transmission range of corrosion potential, the sectional loss of anode, and the corrosion reduction effect. Therefore, to expect the corrosion reduction effect of rails under the oceanic climate conditions for railway track, it was important to adopted the appropriate spacing of anode installation by considering the actual field conditions.