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Electro chemical characteristics of $(MnX)O_2$ electrode prepared by thermal decomposition method (열분해법으로 제조된 $(MnX)O_2$ 전극의 전기화학적 특성)

  • Kim, Hyun-Sik;Lee, Hae-Yon;Huh, Jeoung-Sub;Kim, Jong-Ryung;Lee, Dong-Yoon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.348-351
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    • 2003
  • 산소 과전압이 낮은 $MnO_2$를 촉매로 사용하여 반도체 산화물계의 산소선택성 전극을 제조하고 산화물 coating층의 미세구조와 전기화학적 특성을 분석하였다. Ti 기판에 열분해 법을 이용하여 $MnO_2$ 피막을 형성하였고, 또한 PVDF : $MnO_2$의 함량비를 1 : 1에서 1 : 40까지 정량적으로 변화시키고 DMF의 함량을 각각의 고정된 PVDF : $MnO_2$의 함량비에서 변화시켜 Pb전극에 1.5 mm/sec의 속도로 5회 dipping하여 $MnO_2$ 피막층을 형성 하였다. $450^{\circ}C$에서 1시간 열분해하여 약 $1\;{\mu}m$$MnO_2$ 피막층이 형성되었으나 Ti 기판과의 접착력이 약하여 피막자체에 대한 전기화학적 특성을 관찰할 수 없었다. PVDF : DMF = 4 : 96인 경우 pb 전극의 피막층이 얇기 때문에 박리현상이 일어났으며 이는 산화물 용제의 낮은 점도 때문인 것으로 판단된다. 또한 PVDF : DMF = 10 : 90의 경우는 5회 dipping 하여 약 $150\;{\mu}m$의 피막층을 형성하였다. PVDF : $MnO_2$의 함량비가 1:1에서 1:6 까지는 DMF의 함량에 무관하게 전극 특성이 나타나지 않았지만 $MnO_2$의 양이 상대적으로 증가하면 cycle이 증가하더라도 거의 일정한 전류 값을 갖고 $MnO_2$와 PVDF의 비가 20:1 이상의 조성에서는 균일한 CV 특성을 나타냈다. 이는 $MnO_2$가 효과적으로 촉매 작용을 한 것으로 판단되며 anodic polarization에 의한 산소 발생 과전압도 약 1.4V 정도로 감소되었다.동등한 MSIL 코드를 생성하도록 시스템을 컴파일러 기법을 이용하여 모듈별로 구성하였다.적용하였다.n rate compared with conventional face recognition algorithms. 아니라 실내에서도 발생하고 있었다. 정량한 8개 화합물 각각과 총 휘발성 유기화합물의 스피어만 상관계수는 벤젠을 제외하고는 모두 유의하였다. 이중 톨루엔과 크실렌은 총 휘발성 유기화합물과 좋은 상관성 (톨루엔 0.76, 크실렌, 0.87)을 나타내었다. 이 연구는 톨루엔과 크실렌이 총 휘발성 유기화합물의 좋은 지표를 사용될 있고, 톨루엔, 에틸벤젠, 크실렌 등 많은 휘발성 유기화합물의 발생원은 실외뿐 아니라 실내에도 있음을 나타내고 있다.>10)의 $[^{18}F]F_2$를 얻었다. 결론: $^{18}O(p,n)^{18}F$ 핵반응을 이용하여 친전자성 방사성동위원소 $[^{18}F]F_2$를 생산하였다. 표적 챔버는 알루미늄으로 제작하였으며 본 연구에서 연구된 $[^{18}F]F_2$가스는 친핵성 치환반응으로 방사성동위원소를 도입하기 어려운 다양한 방사성의 약품개발에 유용하게 이용될 수 있을 것이다.었으나 움직임 보정 후 영상을 이용하여 비교한 경우, 결합능 변화가 선조체 영역에서 국한되어 나타나며 그 유의성이 움직임 보정 전에 비하여 낮음을 알 수 있었다. 결론: 뇌활성화 과제 수행시에 동반되는 피험자의 머리 움직임에 의하여 도파민 유리가 과대평가되었으며 이는 이 연구에서 제안한 영상정합을 이용한 움직임 보정기법에 의해서 개선되었다. 답이 없는 문제, 문제 만들기, 일반화가 가능한 문제 등으로 보고, 수학적 창의성 중 특히 확산적 사고에 초점을 맞추어 개방형 문제가 확산적 사고의 요소인 유창성, 독창성, 유연성 등에 각각 어떤 영향을 미치는지 20주의 프로그램을 개발, 진행하여 그 효과를 검증하고자

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The Comparison of Protective Effects of Adenosine Included Cardioplegia According to Adenosine Dosage (심정지액 속에 포함된 아데노신의 용량에 따른 심근보호 효과 비교)

  • 유경종;강면식;이교준;임상현;박한기;김종훈;조범구
    • Journal of Chest Surgery
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    • v.31 no.9
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    • pp.837-844
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    • 1998
  • Background: Adenosine is secreted by myocardial cells during myocardial ischemia or hypoxia. It has many beneficial effects on arrhythmias, myocardial ischemia, and reperfusion ischemia. Although many investigators have demonstrated that cardioplegia that includes adenosine shows protective effects in myocardial ischemia or reperfusion injury, reports of the optimal dose of adenosine in cardioplegic solutions vary. We reported the results of beneficial effects of single dosage(0.75 mg/Kg/min) adenosine by use of self-made Langendorff system. But it is uncertain that dosage was optimal. The objective of this study is to determine the optimal dose of adenosine in cardioplegic solutions. Material and Method: We used a self-made Langendorff system to evaluate the myocardial protective effect. Isolated rat hearts were subjected to 90 minutes of deep hypothermic arrest(15$^{\circ}C$) with modified St. Thomas' Hospital cardioplegia including adenosine. Myocardial adenosine levels were augmented during ischemia by providing exogenous adenosine in the cardioplegia. Three groups of hearts were studied: (1) group 1 (n=10) : adenosine - 0.5 mg/Kg/min, (2) group 2(n=10): adenosine -0.75 mg/Kg/min, (3) group 3 (n=10) : adenosine -1 mg/Kg/min. Result: Group 3 resulted in a significantly rapid arrest time of the heart beat(p<0.05) but significantly slow recovery time of the heart beat after reperfusion(p<0.05) compared to groups 1 and 2. Group 2 showed a better percentage of recovery(p<0.05) in systolic aortic pressure, aortic overflow volume, coronary flow volume, and cardiac output compared to groups 1 and 3. Group 1 showed a a better percentage of recovery(p<0.05) in the heart rate compared to the others. In biochemical study of drained reperfusates, CPK and lactic acid levels did not show significant differences in all of the groups. Conclusion: We concluded that group 2 [adenosine(0.75 mg/Kg/min) added to cardioplegia] has better recovery effects after reperfusion in myocardial ischemia and is the most appropriate dosage compared to group 1 and 3.

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Herbicidal Efficacy of Newly Developed Several Herbicides in Rice (최근(最近) 개발(開發)된 수도용(水稻用) 제초제(除草劑)의 작용성(作用性)과 제초효과(除草效果))

  • Kim, S.C.;Lee, S.K.;Kim, D.S.
    • Korean Journal of Weed Science
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    • v.7 no.2
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    • pp.208-219
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    • 1987
  • Newly developed several herbicides were evaluated as paddy rice herbicide at the Yeongnam Crop Experiment in 1986. And also, the general situation of rice cultivation between Korea and Japan was compared. Twenty-nine herbicides of the total 59 herbicides were used as paddy rice field in Korea while these were 100 and 187, respectively, in Japan. Among paddy rice herbicides, butachlor was the most important herbicide in both countries. However, the degree of concentration to a particular herbicide was greater in Korea compared to Japan; consumption rate of single butachlor to the total herbicide were 66.5% for Korea and 11.9%r for Japan, respectively. Pyrazolate, pyrazoxyfen and quinclorac were the most promising hebicides in pressed-type rice nurserybed in terms of herbicidal efficacy and phytotoxic effect. For transplanted paddy rice field, single application of NC-311 or combining applications of NC-311 with butachlor or quinclorac gave excellent results at the weed community that was dominated by Echinochloa crus-galli, Aneilema japonica, Ludwigia prostrata, Scirpus hotarui, Cyperus serotinus, Potamogeton distinctus and Eleocharis kuroguwai. Particularly the above combining applications maintained their excellent herbicidal effect up to 3 leaf stage of E. crus-galli without arising herbicidal phytotoxicity. Pyrazolate and three sulfonyl urea herbicides (DPX-5384, NC-311 and CGA 142464) exhibited very high safety against rice. However, Japonica type rice cultivar was a little bit more sensitive than Indica/Japonica type rice cultivar. On the other hand, the effect of these herbicides against E. crus-galli was very strong. Herbicidal effect against E. crus-galli was enhanced through shoot absorption for sulfonyl urea herbicides and root abosorption for pyrazolate and quinclorac, respectively.

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Clinical Presentations and Causative Organisms in Children and Adolescents with Osteoarticular Infections: A Retrospective Study (소아청소년기에 발생한 골관절염의 임상 양상 및 원인균에 대한 고찰)

  • Lee, Soyoung;Kim, Han Wool;Cho, Hye-Kyung;Yun, Yoe Hon;Ryu, Kyung Ha;Kim, Kyung-Hyo
    • Pediatric Infection and Vaccine
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    • v.22 no.3
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    • pp.154-163
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    • 2015
  • Purpose: Osteoarticular infections in children and adolescents are important because it can cause functional compromise if appropriate treatment is delayed. Therefore, this study was designed to describe the clinical presentations and causative organisms of osteoarticular infections in children and adolescents in order to propose early diagnosis method and an appropriate empiric antimicrobial therapy. Methods: Forty-two medical records were reviewed retrospectively, which were confirmed as osteomyelitis (OM) or septic arthritis (SA) at Department of Pediatrics or Orthopedic Surgery in patients under 18 years old of Ewha Womans University Mokdong Hospital from March 2008 to March 2015. Results: We identified 21 cases of OM, 13 cases of SA and 8 cases of OM with SA. There were 31 males and 11 females and mean age was 7.1 years old. The most common symptoms were pain and tenderness of involved site. Major involved bones were femur (10 cases, 34.5%), tibia (7 cases, 24.1%) and major involved joints were hip (9 cases, 42.9%), and knee (5 cases, 23.8%). Increased serum C-reactive protein and erythrocyte sedimentation rate were observed in 37 cases (88.1%) respectively. Magnetic resonance imaging was performed in 40 cases among 42 cases and was used to demonstrate osteoarticular infections and other adjacent infections. Nine cases (23.7%) among 38 cases and 20 cases (50.0%) among 40 cases were positive in blood culture and infected site culture respectively. The most common causative organism was Staphylococcus aureus, which was represented in 22 cases (75.9%), of which nine cases (40.9%) were resistant to methicillin. Conclusions: S. aureus was the most common causative organism of osteoarticular infections in children and adolescents and the proportion of MRSA was high in this study. Therefore, we recommend vancomycin as the first empiric antimicrobial therapy and suggest that further study is necessary to elucidate an appropriate guideline for treatment which takes into account MRSA proportion.

Estimation of Linkage Disequilibrium and Effective Population Size using Whole Genome Single Nucleotide Polymorphisms in Hanwoo (한우에서 전장의 유전체 정보를 활용한 연관불평형 및 유효집단크기 추정에 관한 연구)

  • Cho, Chung-Il;Lee, Joon-Ho;Lee, Deuk-Hwan
    • Journal of Life Science
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    • v.22 no.3
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    • pp.366-372
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    • 2012
  • This study was conducted to estimate the extent of linkage disequilibrium (LD) and effective population size using whole genomic single nucleotide polymorphisms (SNP) genotyped by DNA chip in Hanwoo. Using the blood samples of 35 young bulls born from 2005 to 2008 and their progenies (N=253) in a Hanwoo nucleus population collected from Hanwoo Improvement Center, 51,582 SNPs were genotyped using Bovine SNP50 chips. A total of 40,851 SNPs were used in this study after elimination of SNPs with a missing genotyping rate of over 10 percent and monomorphic SNPs (10,730 SNPs). The total autosomal genome length, measured as the sum of the longest syntenic pairs of SNPs by chromosome, was 2,541.6 Mb (Mega base pairs). The average distances of all adjacent pairs by each BTA ranged from 0.55 to 0.74 cM. Decay of LD showed an exponential trend with physical distance. The means of LD ($r^2$) among syntenic SNP pairs were 0.136 at a range of 0-0.1 Mb in physical distance and 0.06 at a range of 0.1-0.2 Mb. When these results were used for Luo's formula, about 2,000 phenotypic records were found to be required to achieve power > 0.9 to detect 5% QTL in the population of Hanwoo. As a result of estimating effective population size by generation in Hanwoo, the estimated effective population size for the current status was 84 heads and the estimate of effective population size for 50 generations of ancestors was 1,150 heads. The average decreasing rates of effective population size by generation were 9.0% at about five generations and 17.3% at the current generation. The main cause of the rapid decrease in effective population size was considered to be the intensive use of a few prominent sires since the application of artificial insemination technology in Korea. To increase and/or sustain the effective population size, the selection of various proven bulls and mating systems that consider genetic diversity are needed.

Temporal and spatial distributions of heat fluxes in the East Sea(Sea of Japan) (東海熱收支 의 時.空間的인 分布)

  • 박원선;오임상
    • 한국해양학회지
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    • v.30 no.2
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    • pp.91-115
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    • 1995
  • Air-sea heat fluxes in the East Sea were estimated from the various ship's data observed from 1961 to 1990 and the JMA buoy #6 data from 1976 to 1985. The oceanic heat transport in the sea was also determined from the fluxes above and the heat storage rate of the upper layer of 200m from the sea surface. In winter, The incoming solar radiation is almost balanced with the outgoing longwave radiation. but the sea loses her heat through the sea surface mainly due to the latent and sensible heat fluxes. The spatial variation of the net surface heat flux is about 100 Wm/SUP -2/, and the maximum loss of heat is occurred near the Tsugaru Strait. There are also lots of heat losses in the southern part of the East Sea, Korea Strait and Ulleung Basin. Particularly, the heat strong loss in the south-western part of the sea might be concerned with the formation of her Intermediate Homogeneous Water. In summer, the sea is heated up to about 120∼140 Wm/SUP -2/ sue to strong incoming solar radiation and weak turbulent heat fluxes and her spatial variation is only about 20 Wm/SUP -2/. The oceanic heat flux is positive in the southeasten part f the sea and the magnitude of the flux is larger than that of the net surface heat flux. This shows the importance of the area. In the southwestern part of the sea, however, the oceanic heat flux is negative. This fact implies cold water inflow, the North Korean Cold Water. The sigh of net surface heat flux is changed from negative to positive in March and from positive to negative in September. The heat content in the upper surface 200 m from the sea surface reaches its minimum in March and maximum in October. The annual variation of the net surface heat flux is 580 Wm/SUP -2/ in southwestern part of the sea. The annual mean values of net surface heat fluxes are negative, which mean the net heat transfer from the sea to the atmosphere. The magnitude of the flux is about 130 Wm/SUP -2/ near the Tsugaru Strait. The net surface fluxes in the Korea Strait and the Ulleung Basin are relatively larger than those of the rest areas. The spatial mean values of surface heat fluxes from 35$^{\circ}C$ to 39$^{\circ}$N are 129, -90, -58, and -32 Wm/SUP -2/ for the incoming solar radiation, latent hear flux, outgoing longwave radiation, and sensible heat flux, respectively.

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Effects of Pig Slurry Application on Body Weight Gain of Grazing Hanwoo Heifer and Forage Yields in a Grass-Legume Mixed Pasture (방목초지 돈분액비 시용이 목초 생산성 및 방목한우 증체에 미치는 영향)

  • Ko, S.B.;Park, N.G.;Hwang, K.J.;Lee, C.E.;Kang, S.Y.
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.23 no.4
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    • pp.255-264
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    • 2003
  • A study was conducted to determine the effects of pig slurry application on forage yield and growth of fazing Hanwoo heifer in a mixed pasture. To each of three treatments 1.4ha were alloted a control applied with only chemical fertilizer (N-P-K=150-150-120kg/ha), two pig slurry lots applied with the amount to allow 100% (150 kg/ha) or 150% (225 kg/ha) of N used in the control. A randomized block design was used without replication. Cattle were allowed to graze continuously during the experimental period. Results obtained were as follows: Total dry matter yield was 16,291, 15,632 and 16,320 kg/ha for chemical fertilizer. pig slurry 100% and 150%, respectively. The pasture was dominated by perenial ryegrass during the first gazing season, but by orchard grass and perenial ryegrass (60∼70%) and red clover (20∼30%) during the second grazing season. Average gazing rate per ha was 2.75∼2.76 animal units and daily weight gain of grazing cattle was not different among treatments ranging from 0.563 to 0.580 kg. Total weight gain of grazing cattle per ha during the grazing period was 541, 541 abd 555 kg for chemical fertilizer, pig -slurry 100 and 150%, respectively. RBC, WBC, total protein and albumin etc. concentrations in blood were normal in all treatments.

Antibiotic Susceptibility of Salmonella spp. Isolated From Diarrhoea Patients in Seoul From 1996 to 2001 (서울 시내 설사환자에서 분리한 살모넬라의 항생제 감수성의 년도별 변화 추이)

  • 박석기;박성규;정지헌;진영희
    • Journal of Food Hygiene and Safety
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    • v.17 no.2
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    • pp.61-70
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    • 2002
  • In order to investigate the classification and antibiotic resistance of Salmonella species,718 isolates were isolated from patient in Seoul from 1996 to 2001. The two hundred and ninety eight isolates (41.5%) were identified as Sal. Enteritidis, followed by Sal. Typhi 218 isolates (30.4%), and Sal. Typhimurium 87 isolates (12.1%). The identified Salmonella species were most resistant to tetracycline (32.7%), followed by streptomycin (28.0%), ticarcillin (18.1%) and ampicillin (12.4%). Among isolates,34.7% of Sal. Enteritidis were resistant to tetracycline, 32.3% to streptomycin,23.2% to ticarcillin,13.5% to ampicillin, respectively. 13.8% of Sal. Typhi were resistant to streptomycin,10.6% to tetracycline, respectively.66.7% of Sal. Typhimurium were resistant to tetracycline, 42.5% to streptomycin, 28.7% to ticarcillin, 26.4% to ampicillin and 17.2% to chloramphenicol, respectively. Of 718 isolates, 324 isolates (45.1%) were resistant to 1 or more drugs and 64 isolates (19.8%) were resistant to 1 drug, 132 isolates (40.7%) were resistant to 2 drugs,50 isolates (15.4%) were resistant to 3 drugs, 27 isolates (8.3%) to 4 drugs,27 isolates (8.3%) to 5 drugs,22 Isolates (6.8%) to 6 drugs. The most prevalent multiple resistant pattern was tetracycline-kanamycin (35.5%), followed by tetracycline-kanamycin-ticarcillin (8.3%), and tetracycline-kanamycin-ticarcillin-ampicillin (7.4%) . Antibiotic resistant rate of Sal. Typhimurium was 73.6%,1311owe4 by Sal. Enteritidis 53.7% and Sal. Typhi 19.3%. Most Sal. Enteritidis was resistant to 1 drug o.2 drugs, whereas Sal. Typhi. and Sal.. Typhunurium were more .resistant to 5 (16.7%) or 6 drugs (26.6%). The old generation antibiotics such as ampicillin, tetracycline, and streptomycin were annually more resistant than the new generation antibiotics such as ceftriaxone, ciprofloxacin or cefoxitin.

The Effect of Repetitive Insertion and Pullout of Spinal Screws on Pullout Resistance : A Biomechanical Study (척추 수술에 사용되는 나사못의 반복 삽입과 인출이 인장항력에 미치는 영향 : 생체 역학적 연구)

  • Bak, Koang Hum;Ferrara, Lisa;Kim, Kwang Jin;Kim, Jae Min;Kim, Choong Hyun;Benzel, Edward C.
    • Journal of Korean Neurosurgical Society
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    • v.30 no.2
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    • pp.131-136
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    • 2001
  • Object : The clinical uses of screws are increasing with broader applications in spinal disorders. When screws are inserted repeatedly to achieve optimal position, tips of screw pitch may become damaged during insertion even though there are significant differences in the moduli of elasticity between bone and titanium. The effect of repeated screw insertion on pullout resistance was investigated. Methods : Three different titanium screws(cortical lateral mass screw, cancellous lateral mass screw and cervical vertebral body screw) were inserted into the synthetic cancellous material and then extracted axially at a rate of 2.4mm/min using Instron(Model TT-D, Canton, MA). Each set of screws was inserted and pulled out three times. There were six screws in each group. The insertional torque was measured with a torque wrench during insertion. Pullout strength was recorded with a digital oscilloscope. Results : The mean pullout force measurements for the cortical lateral mass screws($185.66N{\pm}42.60$, $167.10N{\pm}27.01$ and $162.52 N{\pm}23.83$ for first, second and third pullout respectively : p=0.03) and the cervical vertebral body screws($386.0N{\pm}24.1$, $360.2N{\pm}17.5$ and $330.9N{\pm}16.7$ : p=0.0024) showed consecutive decrease in pullout resistance after each pullout, whereas the cancellous lateral mass screws did not($194.00N{\pm}36.47$, $219.24N{\pm}26.58$ and 199.49N(36.63 : p=0.24). The SEM after insertion and pullout three times showed a blunting in the tip of the screw pitch and a smearing of the screw surface. Conclusions : Repetitive screw insertion and pullout resulted in the decrease of pullout resistance in certain screws possibly caused by blunting the screw tip. This means screw tips suffer deformations during either repeated insertion or pullout. Thus, the screws that have been inserted should not be used for the final construct.

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High School Students' Preferences and Food Intake on Menu Items Offered by School Foodservice in Daegu (대구지역 학교급식 식단에 대한 고등학생의 기호도와 섭취율)

  • Kim, So-Hee;Cha, Myeong-Hwa;Kim, Yoo-Kyeong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.7
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    • pp.945-954
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    • 2006
  • The purpose of this study is to present basic data for an improvement of school foodservice by indentifying students' preference level for school meal menu and assessing students' nutrition intake. The subjects participated in this study were 544 high school students on 1st grade served by self-operated school foodservice in Daegu. The frequency analysis, t-test analysis, and correlation analysis were carried out for the data analysis using SPSS 12.0 program. Based on the results toward students' preference and serving frequency, the most frequently offered food was soup sorts and then followed by the categories of boiled rice, kimchi, broiled food and hard-boiled food. Boiled rice, rice with assorted vegetables, mandu soup, salad and braised beef rib were highly preferred to the students. Male students scored higher preference to the menu related with meats than female students. However, the students' preference and serving frequency on the menu were not correlated significantly in this study. A substantial correlation was found between the degree of preference and the rate of intake (p<0.01). It would be generalized that preferences to menu items strongly sffected the level of intake by students. The nutrient analysis of food intake revealed that both male and female students were not consuming sufficient level of calorie, calcium and vitamin $B_2$. In conclusion, the results indicate that the students' preference is a very important variable influencing the consumption level of meal as well as balanced nutrient intake by students served in school foodservice. Menu planning should be integrated into school foodservice management for quality control. As limited control of the menu may also negatively influence on the food leftovers and ecological issues, professionals related to the school foodservice including administers, educators and dieticians need to check up the students' preference regularly and reflect their perception on the menu planning to improve the quality of school foodservice. The nutrient intake currently provided through school foodservice should be also assessed more thoroughly. These data could be incorporated into continuous quality improvement and strategic planning in school foodservice.