• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
• /
• pp.239-242
• /
• 2002

This study is intended to investigate the relationship between rebound value of P type schmidt hammer and the compressive strength with various aggregates, and a series of experiments about early strength quality control by P type schmidt hammer was performed. According to the results, the compressive strength of concrete using basalt and limestone aggregate is higher by 3% and lower by 4% than that of concrete using granite aggregate respectively. Concrete using basalt and lime stone aggregate show high rebound value in vertical strike. Estimation of the compressive strength does not show differences in horizontal strike, but the compressive strength is estimated high in order of granite, basalt and limestone aggregate in vertical strike. A good correlation between the rebound value of schmidt hammer and the compressive strength is confirmed regardless of aggregate types, so it could be possible to control the quality of concrete by P type schmidt hammer test when basalt and limestone aggregates are used at the same time.

• 동아시아식생활학회지
• /
• 제14권3호
• /
• pp.265-274
• /
• 2004

To investigate the effect of cereal powders on the quality and storage characteristics of sausage, Aw, pH, microbial count, TBA value, VBN value, textual and sensory characteristics were examined. Water activity tended to decrease as storage time prolonged and all the samples showed higher Aw's than that of the control. During the storage period, pH values of all the samples decreased. L, a and b values had a tendency to decrease during the storage period. During the four weeks storage at 4$^{\circ}C$, TBA and VBN values of all the sample showed increasing tendency and were lower than those of the control. Total plate counts of bacteria, the number of lactic acid bacteria and coliform bacteria counts increased as the storage time prolonged. Texture characteristics of all samples increased up to 1 week storage and decreased subsequently. The sensory scores of all the samples decreased as the storage time prolonged.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
• /
• pp.157-162
• /
• 2002

This study is intended to present a reference data for effective quality control of concrete through comparing the rebound value of P type schmidt hammer with the compressive strength with variation of mix proportion and curing condition. According to the results, the air-curing specimen shows the higher rebound value than standard specimen except high strength in the whole. Also the vertical stroke shows higher rebound value than horizontal stroke in standard specimen, however, the rebound value of the two does not show prominent difference in air-curing specimen. The estimation equation of compressive strength derived from this experiment estimates the compressive strength more largely than the estimation equation in P type schmidt hammer manual. Therefore it is thought that the new estimation equation that fits our condition will have to be presented.

• 한국환경과학회지
• /
• 제17권10호
• /
• pp.1139-1146
• /
• 2008

To investigate the functional properties and the antioxidant effect of pine needle(Pinus densiflora), the pine needle extract was obtained with methanol and its functionality was measured by spectrophotometric method, and the antioxidant experiment on soybean oil was carried out by the active oxygen method. The extraction yield of pine needle with 99% methanol was about 19%, the total flavonoid content of the pine needle-methanol extract was 11.32 mg/g on dry basis and the superoxide dismutase-like activity was 94.3%. The nitrite scavenging ability of the extract was pH dependent with the values of 77.44% at pH 1.2, 48.45% at pH 3.0 and 11.04% at pH 6.0, respectively. The peroxide value was 92.6 meq/kg at 5% dosage, 138.4 meq/kg at 2% dosage of the extract on 8 oxidation days. The period of the peroxide value to be 100 mg/kg was 4.9, 6.3 and 8.5 days at control, 2% and 5% dosage of extract, respectively. And the relative antioxidant effectiveness of the extract was 27.9% and 72.3% increase at 2% and 5% dosage, respectively, compared to control. The thiobarbituric acid value showed few differences within 4 oxidation days, but with the dosage of the extract it fairly decreased with considerable antioxidant effect to control above 4 days.

• 한국태양에너지학회 논문집
• /
• 제32권spc3호
• /
• pp.255-261
• /
• 2012

Since PV PCS uses output current sensor for ac output current control, the sensor's sensing value includes unnecessary offset inevitably. If PV inverter is controlled by the included offset value, it's output current will generate DC offset. The DC offset of output current for trans-less PV inverter is fatal to grid, which results in saturating grid side transformer. Usually DSP controller of PV inverter reads several times sensing value during initial operation and, finally, it's average value is used for offset calibration. However, if temperature changes, the offset changes, too. And also, the switch device is not ideal, both each switching element of the voltage drop difference and on & off time delay difference generate DC offset. Thus, to compensate for deadtime and the switch voltage drop, feedback control by output current DC offset should be provided to compensate additional distortion of the output current. The validity of the proposed method is confirmed through PSIM simulation.

• Asian-Australasian Journal of Animal Sciences
• /
• 제17권6호
• /
• pp.857-862
• /
• 2004

The present study was carried out to examine the changes in functional properties of cholesterol-removed compound whipping cream made by $\beta$-CD treated cream and palm oil. Six different ratios of cream to palm oil (10:0 as control, 9:1, 8:2, 7:3, 6:4, and 5:5, v/v) were tested. The overrun percentage increased with an increased amount of palm oil. When the ratio of cream to palm oil was 10:0 (control), the overrun was 130%, which was significantly lower than other ratios reached to 150%. Foam instability was measured as 3.1 ml defoamed cream in control, however, the value of foam instability decreased with an increase of palm oil addition. The TBA value of cholesterol-removed compound whipping cream increased from 0.08 to 0.13 with no addition of palm oil during 4 wk storage. When the ratio of cream to palm oil was 5:5, TBA value increased dramatically at 3 wk and thereafter. Among sensory characteristics, texture value increased with higher amount of palm oil, however, flavor and overall preferences were opposite. Above results indicated that partial substitution of palm oil in manufacture of cholesterol-removed compound whipping cream resulted in a stable foam development with little adverse effect on flavor and lipid oxidation during storage. The present study showed a possible application in manufacture of cholesterol-removed compound whipping cream, which may be effective in other foods.

• 동아시아식생활학회지
• /
• 제20권1호
• /
• pp.122-127
• /
• 2010

This study involved the making of sugar snap cookies with the addition of carrot powder at two to twelve percent which furnishes modern people with much lacking and needed dietary fiber. The review of the physiochemical properties, rheology and sensory evaluation of such contents resulted in the following findings: The sedimentation value and Pelshenke value all decreased in weak flour with the addition of more carrot powder, in comparison with the control group. The water retention capacity (WRC) and alkaline water retention capacity (AWRC) all increased in weak flour with the addition of more carrot powder in comparison with the control group. As for the gelatinization properties of the test samples measured by rapid visco-analysis, the addition of more carrot powder resulted in the initial pasting temperatures increasing in the case of weak flour, yet showing no significant difference between the control group and the carrot-added groups, as well as the maximum viscosity, minimum viscosity and final viscosity all showed the tendency of decreasing. The addition of more carrot powder led to the peak times in the mixographs for weak flour all exhibiting the tendency of decreasing, which might be interpreted as gradually weaker physical properties of the dough as well as less stability in the shape of the dough in turn.

• 한국조리학회지
• /
• 제23권8호
• /
• pp.11-16
• /
• 2017

In this study, two kinds of mealworm seasoning pastes (naturally fermented or inoculation of Bacillus subtilis) were prepared by applying fermentation method of chungkukjang. The samples were labeled into soybean control (SC; no fermentation), mealworm control (MC; no fermentation), mealworm natural fermentation (MR) and mealworm inoculated fermentation of Bacillus (MB). Water content, color, pH, titratable acidity, salinity, amino acid nitrogen, reducing sugar and preference test were examined on the pastes. Moisture contents were 46.9 with soybean control (MC) and 54.5~73.3 with mealworm pastes. The L-value was not significantly different between the samples. In the case of the a-value and the b-value, SC showed the highest value whereas mealworm pastes showed lower values than SC. pH and salinity were higher in mealworm pastes. Amino nitrogen and reducing sugar showed the highest values of MR 326,67 and 63.33 mg%, respectively. In the preference test, the appearance and flavor were the highest values with SC, but texture, taste and overall acceptability were with MR, Therefore, soybean fermentation method with Bacillus species could be applied to use protein of mealworm and possibly edible insects as well.

• 한국식품영양과학회지
• /
• 제28권5호
• /
• pp.1064-1068
• /
• 1999

This study was quality changes of sulgiduk added green tea powder during storage. Sulgiduk prepared with various concentrations of green tea powder; 0%(control group), 0.5%(GT 0.5 group), 1%(GT 1.0 group), 1.5%(GT 1.5 group), 2%(GT 2.0 group), and the changes of its quality during 7 days of storage were investigated. Total microbe numbers, the acidity and pH in sulgiduk during storage were decreased with increasing the added amounts of a green tea powder, and especially those of GT 1.0 and GT 1.5 groups had relatively the lower than other groups. The "L" value(lightness) of the control group was the highest among five groups, and its value was decreased throughout storage, and especially GT 0.5 groups had the lowest brightness. The "a" value(reddness) of the control group was higher than other four groups, and increased GT 2.0>GT 1.5>GT 1.0>GT 0.5 groups, in that order. The "b" value(yel lowness) was increased in the order; GT 2.0>GT 1.5>GT 1.0>GT 0.5 groups. These results indicated that GT 1.0 group showed the best quality than other groups of sulgiduk during storage. of sulgiduk during storage.

• 한국조리학회지
• /
• 제22권8호
• /
• pp.99-108
• /
• 2016

This study was conducted to investigate the effect of Chinese artichoke powder on the physicochemical properties and the sensory characteristics of yanggaeng. According to the increasing contents of Chinese artichoke powder, the $^{\circ}Brix$ value and pH levels of yanggaeng were significantly decreased whereas the moisture contents of yanggaeng was significantly increased. The result of color measurement shown that L value of groups containing Chinese artichoke powder was lower than that of control group, but a value and b value of groups containing Chinese artichoke powder were higher. Texture measurement score in terms of cohesiveness, chewiness, and brittleness for yanggaeng were significantly decreased according to the levels of added Chinese artichoke powder content. The contents of total polyphenol, DPPH radical scavenging activity, and NSA of groups containing Chinese artichoke powder were higher than those of control group. As Chinese artichoke powder increased, antioxidative activity also became bigger. Sensory evaluation scores in terms of appearance, odor, taste, texture, and overall preference of groups with 2% and 4% of Chinese artichoke powder did not show any significantly differences when compared to the control group. Based on these findings, current study suggest that addition of 4% Chinese artichoke powder was the best substitution ratio for yanggaeng.