• 제목/요약/키워드: pH threshold

검색결과 163건 처리시간 0.024초

열탕 가열 중 한우 홍두깨살 및 아롱사태의 중심온도가 가열감량, 보수력, 표면색도 및 조직감에 미치는 영향 (Effects of Internal Temperature on Physical Properties of Hanwoo Beef Eye of Round and Center of Heel during Boiling)

  • 문윤희
    • 동아시아식생활학회지
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    • 제23권4호
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    • pp.403-412
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    • 2013
  • 한우의 홍두깨살과 아롱사태를 열탕에서 가열하는 동안 중심온도에 따른 물리적 특성 변화를 확인하였다. 홍두깨살과 아롱사태의 pH 값은 각각 중심온도 $40^{\circ}C$$50^{\circ}C$에서 생육의 pH 값보다 유의적(p<0.05)으로 상승하기 시작하여 각각 $70^{\circ}C$$80^{\circ}C$에서 가장 크게 변화한 후, 그 이상의 온도에서는 유의적 차이를 나타나지 않았다. 홍두깨살과 아롱사태의 표면색도에서 $L^*$값은 각각 $50^{\circ}C$$60^{\circ}C$까지 유의적으로 높아졌으나, $a^*$값 및 $b^*$값은 모두 $80^{\circ}C$까지 낮아졌으며 (p<0.05), 모두 그 이상의 온도에서는 유의적 차이가 없었다. 홍두깨살과 아롱사태의 중심온도가 각각 $60^{\circ}C$$70^{\circ}C$에서 가열감량이 가장 높은 반면 보수력은 가장 낮게 나타났으며, 그 이상의 온도에서는 유의적 차이를 보이지 않았다. 홍두깨살과 아롱사태의 조직감에서 경도, 뭉침성 및 저작성은 각각 $70^{\circ}C$$80^{\circ}C$에서 가장 크게 변하고, 응집성은 각각 $60^{\circ}C$$70^{\circ}C$에서 가장 크게 변하였으며, 그 이상의 온도에서는 유의적 차이를 나타나지 않았다. 탄력성은 홍두깨살과 아롱사태의 중심온도가 각각 $70^{\circ}C$$80^{\circ}C$에서 유의적으로 높아진 후두 부위 모두 $90^{\circ}C$부터 유의적으로 낮아졌다(p<0.05). 홍두깨살은 아롱사태보다 가열에 의한 물리적 특성 변화가 빠르게 나타났다.

알루미늄 응집제를 사용한 호수수질 개선 사례 연구 (The Application of Aluminum Coagulant for the Improvement of Water Quality in Three Recreational Ponds)

  • 강필구;김범철
    • 생태와환경
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    • 제36권4호통권105호
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    • pp.447-454
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    • 2003
  • 부영양호의 수질정화를 위하여 알루미늄 응집제를 호수에 첨가하고 조류와 부유물의 침강제거효과, 및 인의 감소효과를 측정하였다. 서울 석촌호와 강원대학교 구내 연못을 대상으로 8회에 걸쳐 첨가량을 달리하여 실시하였다. 7회의 처리에서는 황산알루미늄을 사용하였고 1회는 PAC를 사용하였다. 부유물질의 침강제거효과는 첨가량에 따라 좌우되었다. 10.0 mgAl/l를 첨가한 경우에는 부유물질, 조류, 인 등이 완전히 제거되었으나, 3.3 mgAl/l와 1.8 mgAl/l를 첨가한 경우에는 부분적인제거 효과가 있었다. 그러나 0.45 mgAl/l로 첨가한 경우에는 거의 개선효과가 보이지 않았다. 알루미늄 첨가가 부유물을 침전제거에 효과를 나타내기 위해서는 최소역치 (약 5 mgAl/l) 이상을 투여하여야 하는 것으로 결론지을 수 있다. 효과 지속시간은 외부로부터의 추가부하량 유입에 의해 좌우되는 것으로 보인다. 석촌호에서는 인근 하천수의 펌핑에 의해 곧 다시 혼탁해 졌으며, 구내연못에서는 강우후 주변의 토사가 유입되거나 지하수 펌핑으로 영양염류가 유입되면 곧 다시 조류가 번성하고 혼탁해 졌다. 응집제 투여의 결과로 pH가 지나치게 낮아지는 피해나 어패류에 대한 유해성 징후는 발견되지 않았다. 외부 오염원을 제거할 수 없는 호수에서는 응집제의 투여가 호수수질 개선의 임시적 대안으로 활용될 수 있을 것으로 보인다.

Chemical Characteristics of Groundwater in Carbonate Rock Areas of Korea

  • Kabir, Mohammad Lutful;Park, Youngyun;Lee, Jin-Yong
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제19권2호
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    • pp.7-15
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    • 2014
  • This study was conducted to understand the chemical characteristics of groundwater in carbonate areas of Korea. In this study, data on pH, electric conductivity (EC), $Ca^{2+}$, $Mg^{2+}$, $Na^+$, $K^+$, $Cl^-$, $SO_4{^{2-}}$, and $HCO_3{^-}$ were collected from 97 wells which were installed in various carbonate rock regions of Korea. The pH values ranged from 5.7 to 9.9, and the average value was 7.3. The concentration range showed differences between the maximum value of $HCO_3{^-}$ and the medium to minimum values of $Ca^{2+}$, $Mg^{2+}$, $Na^+$, $Cl^-$, $SO_4{^{2-}}$, and $K^+$ in the study area. The average value of EC was $374{\mu}S/cm$, higher than in granite and gneiss areas, where the value is $176{\mu}S/cm$. Most of the groundwater was type $Ca-HCO_3$, and some was type $Mg-HCO_3$. The relationship between $Ca^{2+}$, $Cl^-$, and $HCO_3{^-}$, respectively, and EC showed relatively significant positive correlations compared to the other dissolved components. However, the determination coefficients for $Mg^{2+}$, $Na^+$, $SO_4{^{2-}}$, and $K^+$ were very low less than 0.2. These results indicate that the source of $Ca^{2+}$ and $Mg^{2+}$ is relatively simple (carbonate dissolution) compared to other sources. The sources of $Na^+$, $K^+$, $Cl^-$, $SO_4{^{2-}}$, and $HCO_3{^-}$ might be not only water-rock interactions, but also irrigation return flow, because many groundwater wells had been developed for irrigation purposes. Subsequently, the influence of agriculture on groundwater chemistry was evaluated using a cumulative plot of $SO_4{^{2-}}$. The threshold value of $SO_4{^{2-}}$ calculated from the cumulative frequency curve was 29.2 mg/L. Therefore, 12.4% of all the groundwater wells were affected by agricultural activity.

전북지역 밭 토양의 지형별 물리화학적 특성 (Investigation of Relationships between Soil Physico-chemical Properties and Topography in Jeonbuk Upland Fields)

  • 안병구;이제형;김갑철;최동칠;이진호;한성수
    • 한국토양비료학회지
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    • 제43권3호
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    • pp.268-274
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    • 2010
  • 전북지역 밭 토양의 화학적 특성은 150개 지점, 물리적 특성은 84개 지점에 대하여 토양의 물리화학적 특성을 조사하였다. 화학적 특성 조사지역의 지형분포는 곡간 및 선상지 (34.7%), 구릉 및 산악지 (18.7%), 산록경사지 (20.0%), 하성평탄지 (14.0%), 홍적대지 (8.0%) 및 하해혼성평탄지 (4.6%)로 나타났다. 물리적 특성인 토성은 사양토, 사질식양토, 식양토, 식토로 구성되어 있었고 사질식양토가 모든 지형에 고르게 분포하였고, 모든 조사지점의 경사도는 최적조건 (0~15%)을 보였다. 지형별 용적밀도는 1.19~1.24 Mg $m^{-3}$이었고, 경도는 12.1~13.9 mm이었다. 지형에 관계없이 밭 토양의 화학성인 pH는 37.3%, 유기물함량 42.7%, EC는 93.0%가 적정수준이었지만, 유효인산함량은 42.7%, 치환성 K는 64.0%, Ca은 47.3%, Mg은 48.7%가 적정수준 이상이었다. 토양 pH는 하해혼성평탄지를 제외하고 pH 5.9~6.1 수준이었고, 유기물함량은 산록경사지에서 20.6 g $kg^{-1}$로 가장 높았다. 유효인산은 하해혼성평탄지를 제외하고 534~739 mg $kg^{-1}$이었고, 치환성 K는 홍적대지에서 1.28 $cmol_c\;kg^{-1}$로 가장 높았고, Ca은 하해혼성평탄지와 홍적대지에서 각각 3.79와 4.9 $cmol_c\;kg^{-1}$로 낮았지만, Mg은 지형별로 차이가 없었다. 한편 CEC는 하해혼성평탄지를 제외하고 10.4~10.9 $cmol_c\;kg^{-1}$ 수준을 보였다. 지형별 중금속함량은 토양오염우려기준보다 훨씬 낮은 수준으로 전북지역 밭 토양은 안전한 것으로 조사되었다.

강원도 고랭지 채소 재배지의 토양 비옥도관리 현황과 전망 (Fertility Status in Northeastern Alpine Soils of South Korea with Cultivation of Vegetable Crops)

  • 양재의;조병옥;신영오;김정제
    • 한국토양비료학회지
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    • 제34권1호
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    • pp.1-7
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    • 2001
  • 지난 2, 30년 동안에 진행되고 있는 한국인의 식생활변화와 함께 채소 작물에 대한 수요가 급격히 증가하면서 강원도 고랭지 토양이 여름 채소 재배지로 각광을 받게 되었고 그 재배 면적이 매년 확대 일로에 있다. 이 토양의 비옥도를 유지 내지는 향상시키고 적절한 관리를 기하기 위해 광범위하고 집중적인 조사와 검정을 실시하여 얻은 결과의 일부를 다음과 같이 정리할 수 있었다. 조사된 토양은 일반적으로 양토 내지는 사양토로써 배수가 양호하였으며 대부분 경사지에 놓여 있기 때문에 심할 경우 침식의 위험에 노출되게 되어 경작충이 매우 얕았으며, 이 중 30% 또는 그 이상의 경사도를 가진 토양 11%는 곧 다시 조림해야 할 정도로 농경지로써는 부적절하였다. 이미 받은 침식으로 인해 자갈 함량이 높았으며 토양의 경도 역시 식물의 뿌리 신장과 농기구 사용에 지장을 줄 정도였다. 토양의 pH는 산성화 쪽으로 진행되었고, 유기물 함량, 치환성 염기인 Ca, Mg, 그리고 K의 함량은 경작 연수가 증가함에 따라 감소하였는데 유효 인산 ($P_2O_5$)만은 농가의 퇴구비 과다 사용 결과로 인해 크게 증가하는 경향을 보였다. 양이온 치환용량(CEC)과 전기 전도도(EC)는 토양과 토양 사이에 별 차이가 없었다. 이 지역의 고랭지 토양은 아직 Cd, Cu, Pb, Zn 그리고 Ni등의 중금속 원소에 의한 토양 오염의 영향을 받지 않은 것으로 나타났다.

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Educational Intervention Based on the Health Belief Model to Modify Risk Factors of Cardiovascular Disease in Police Officers in Iran: A Quasi-experimental Study

  • Saffari, Mohsen;Sanaeinasab, Hormoz;Jafarzadeh, Hassan;Sepandi, Mojtaba;O'Garo, Keisha-Gaye N.;Koenig, Harold G.;Pakpour, Amir H.
    • Journal of Preventive Medicine and Public Health
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    • 제53권4호
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    • pp.275-284
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    • 2020
  • Objectives: Police officers may be at a greater risk for cardiovascular disease (CVD) than the general population due to their highstress occupation. This study evaluated how an educational program based on the health belief model (HBM) may protect police officers from developing CVD. Methods: In this single-group experimental study, 58 police officers in Iran participated in a 5-week intervention based on HBM principles. Outcomes included changes in scores on an HBM scale, time spent on moderate to vigorous physical activity (International Physical Activity Questionnaire), body mass index (BMI), blood lipid profile, blood glucose, and blood pressure. The intervention consisted of 5 HBM-based educational sessions. Follow-up was conducted at 3 months post-intervention. The paired t-test was used to examine differences between baseline and follow-up scores. Results: All aspects of the HBM scale improved between baseline and follow-up (p<0.05), except the cues to action subscale. Self-efficacy and preventive behaviors improved the most. BMI decreased from 26.7±2.9 kg/㎡ at baseline to 25.8±2.4 kg/㎡ at follow-up. All components of the lipid profile, including triglycerides, cholesterol, high-density lipoprotein, and low-density lipoprotein, showed significant improvements post-intervention. Blood glucose and blood pressure also decreased, but not significantly. Nearly 25% of participants who were not physically active at baseline increased their physical activity above or beyond the healthy threshold. Conclusions: A relatively brief educational intervention based on HBM principles led to a significant improvement in CVD risk factors among police officers. Further research is needed to corroborate the effectiveness of this intervention.

A Whole Genome Association Study to Detect Single Nucleotide Polymorphisms for Blood Components (Immunity) in a Cross between Korean Native Pig and Yorkshire

  • Lee, Y.M.;Alam, M.;Choi, B.H.;Kim, K.S.;Kim, Jong-Joo
    • Asian-Australasian Journal of Animal Sciences
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    • 제25권12호
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    • pp.1674-1680
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    • 2012
  • The purpose of this study was to detect significant SNPs for blood components that were related to immunity using high single nucleotide polymorphism (SNP) density panels in a Korean native pig (KNP)${\times}$Yorkshire (YK) cross population. A reciprocal design of KNP${\times}$YK produced 249 $F_2$ individuals that were genotyped for a total of 46,865 available SNPs in the Illumina porcine 60K beadchip. To perform whole genome association analysis (WGA), phenotypes were regressed on each SNP under a simple linear regression model after adjustment for sex and slaughter age. To set up a significance threshold, 0.1% point-wise p value from F distribution was used for each SNP test. Among the significant SNPs for a trait, the best set of SNP markers were determined using a stepwise regression procedure with the rates of inclusion and exclusion of each SNP out of the model at 0.001 level. A total of 54 SNPs were detected; 10, 6, 4, 4, 5, 4, 5, 10, and 6 SNPs for neutrophil, lymphocyte, monocyte, eosinophil, basophil, atypical lymph, immuno-globulin, insulin, and insulin-like growth factor-I, respectively. Each set of significant SNPs per trait explained 24 to 42% of phenotypic variance. Several pleiotropic SNPs were detected on SSCs 4, 13, 14 and 15.

Synergistic Effects of Chios Gum Mastic Extract and Low Level Laser Therapy on Osteoblast Differentiation

  • Lee, Ki-Hyun;Kim, Young-Seok;Yu, Su-Bin;Kang, Hae-Mi;Kwak, Hyun-Ho;Kim, In-Ryoung;Park, Bong-Soo
    • International Journal of Oral Biology
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    • 제41권2호
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    • pp.53-62
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    • 2016
  • In the present study, we evaluated the effect of CGM on osteogenic differentiation of cultured osteoblasts, and determined whether combination treatment with LLLT had synergistic effects on osteogenic differentiation. The results indicated that CGM promoted proliferation, differentiation, and mineralization of osteoblasts at the threshold concentration of $10{\mu}g/ml$; whereas, CGM showed cytotoxic properties at concentrations above $100{\mu}g/ml$. ALP activity and mineralization were increased at concentrations above $10{\mu}g/ml$. CGM in concentrations up to $10{\mu}g/ml$ also increased the expression of osteoblast-activated factors including type I collagen, BMP-2, RUNX2, and Osterix. The CGM ($50{\mu}g/ml$) and LLLT (80 mW for 15 sec) combination treatment group showed the highest proliferation levels, ALP activity, and mineralization ratios. The combination treatment also increased the levels of phosphorylated forms of p38, ATF2, PKD, ERK, and JNK. In addition, the osteoblast differentiation factors including type I collagen, BMP-2, RUNX2, and Osterix protein levels were clearly increased in the combination treatment group. These results suggested that the combination treatment of CGM and LLLT has synergistic effects on the differentiation and mineralization of osteoblastic cells.

급성 endosulfan 중독환자에서 경련이 예후에 미치는 영향 (Effect of Seizure on Prognosis in Acute Endosulfan Intoxication)

  • 한병곤;이준호;이경우
    • 대한임상독성학회지
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    • 제7권2호
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    • pp.77-82
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    • 2009
  • Purpose: In highly doses, endosulfan lowers the seizure threshold and elicits central nervous system stimulation, which can result in seizures, respiratory failure, and death. Management of seizure control is essential for survival and prognosis of intoxicated patients. This study assessed whether seizure time was an independent predictor mortality in patients with endosulfan poisoning. Methods: This retrospective study enrolled patients with endosulfan poisoning presenting to Masan Samsung Hospital and Gyeongsang National University Hospital from January 2003 to December 2008. The data were collected from clinical records and laboratory files. Using a multivariate logistic analysis, data on the total population was retrospectively analyzed for association with mortality. Results: Of the 24 patients with endosulfan poisoning, nineteen (79.1%) experienced seizure. The patients in the seizure group showed significantly lower Glasgow coma scale score, base excess, bicarbonate, and significant existence of mechanical ventilation, as compared to the non seizure group (n=5). Seizure, Glasgow coma scale score, systolic blood pressure, bicarbonate level, need for respiratory support, pulse rate, respiratory rate, pH, base excess, and seizure time were associated with mortality. The fatality rate of endosulfan poisoning was 54.1% with higher mortality among patients experiencing. Longer seizure time was associated with higher mortality. Conclusion: Seizure time can be a significant independent predictor of mortality in patients with acute endosulfan poisoning. Physicians should aggressively treat for seizure control in patients with acute endosulfan poisoning.

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Effect of hydrogel-based antibiotic intracanal medicaments on crown discoloration

  • Rayan B. Yaghmoor;Jeffrey A. Platt;Kenneth J. Spolnik;Tien Min Gabriel Chu;Ghaeth H. Yassen
    • Restorative Dentistry and Endodontics
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    • 제46권4호
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    • pp.52.1-52.11
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    • 2021
  • Objectives: This study evaluated the effects of low and moderate concentrations of triple antibiotic paste (TAP) and double antibiotic paste (DAP) loaded into a hydrogel system on crown discoloration and explored whether application of an adhesive bonding agent prevented crown discoloration. Materials and Methods: Intact human molars (n = 160) were horizontally sectioned 1 mm apical to the cementoenamel junction. The crowns were randomized into 8 experimental groups (calcium hydroxide, Ca[OH]2; 1, 10, and 1,000 mg/mL TAP and DAP; and no medicament. The pulp chambers in half of the samples were coated with an adhesive bonding agent before receiving the intracanal medicament. Color changes (ΔE) were detected by spectrophotometry after 1 day, 1 week, and 4 weeks, and after 5,000 thermal cycles, with ΔE = 3.7 as a perceptible threshold. The 1-sample t-test was used to determine the significance of color changes relative to 3.7. Analysis of variance was used to evaluate the effects of treatment, adhesive, and time on color change, and the level of significance was p < 0.05. Results: Ca(OH)2 and 1 and 10 mg/mL DAP did not cause clinically perceivable tooth discoloration. Adhesive agent use significantly decreased tooth discoloration in the 1,000 mg/mL TAP group up to 4 weeks. However, adhesive use did not significantly improve coronal discoloration after thermocycling when 1,000 mg/mL TAP was used. Conclusions: Ca(OH)2 and 1 and 10 mg/mL DAP showed no clinical discoloration. Using an adhesive significantly improved coronal discoloration up to 4 weeks with 1,000 mg/mL TAP.