• 한국산업보건학회지
• /
• 제29권4호
• /
• pp.442-451
• /
• 2019

Objectives: The aim of this study was to review the reduction methods for ammonia (NH₃) and hydrogen sulfide (H₂S) exposure in livestock. Methods: By reviewing domestic and international research reports from Korea and China, reducing ammonia and hydrogen sulfide in livestock pens was analyzed in terms of ventilation, deodorant, and feed additives. In addition, exposure limits in Korea and China were examined through a comparison between 'TLV-TWA and STEL under the Industrial Safety and Health Act in Korea' and 'Management Standards for Air of Livestock Pens in China'. Results and Discussion: In order to effectively control hazardous gases and odors in livestock pens, the enhancement of natural ventilation or the addition of ventilation fans at the pollution source are being examined. Deodorants are used as adsorbents or masking deodorants. Additives to feed were zeolite powder, FeSO₄·7H₂O, enzymes, and microbial preparations. Use of feed additives was low-cost and had significant effects compared to other methods. Zeolite was the most commonly used in feed additive in Chinese cases and proved to be low-cost and effective for reducing harmful gases. Enzyme preparations were shown to stimulate the growth of livestock, but were expensive. Conclusions: This study reviewed and examined domestic and international research papers in Korea and China for reducing ammonia and hydrogen sulfide concentrations in livestock pens. More diverse research and the development of feed additives are needed.

• 대한지구과학교육학회지
• /
• 제2권1호
• /
• pp.80-90
• /
• 2009

The purpose of this study is to investigate the characteristics of the mind maps which were drawn with pencil or color pens by elementary students. For this study, 31 students of the 6th grade were selected and trained mind mapping. After training, the subjects had drawn mind maps with color pens about the ROCK for 15minutes and drew mind maps with pencil after 2days of mind mapping using color pens. In addition to activities of mind mapping, the students handed in their papers which were written one's impression of drawing two kinds of mind mapping. The results were follows: First, in central circle which was linked words connected firstly with ROCK as key word, the difference of 2kinds mind maps were little showed in the quantity and quality of the words, branches and their adequacy. Second, the mind maps using pencils had more words, branches and images than mind maps of using color pens in the whole assessment. Third, the most students suggested that the mind mapping using pencil were advantage to economy of time, retouching words and branches, also the mind mapping using pencil made the students relax the strain for drawing it because of retouching possibility. Consequently, the results of this study suggest the mind mapping using pencil has advantage effect on the purpose of gaining students' thinking abundantly and economy of time in elementary science classes.

• 실천공학교육논문지
• /
• 제15권2호
• /
• pp.389-400
• /
• 2023

정보통신 분야의 기술적 진보를 통해 다양한 종류의 스마트 기기들이 등장하고 활용되면서 사람들의 사용 행태와 환경에도 많은 변화가 발생했다. 이러한 변화는 학습 환경에서도 적용되어, 다양한 스마트 기기들이 학습 환경에 등장하고 있으며 학습자의 학습 행동 양식 또한 달라지고 있다. 이 연구에서는 학습 매체 및 필기 도구로 활용되는 스마트 기기 중 최근 등장한 디지털 펜과 태블릿PC를 중심으로, 이를 활용한 디지털 필기 행동에 대한 학습자의 인식을 알아보고자 한다. 기대 일치 모형을 활용하여, 대학생들의 태블릿PC와 디지털 펜에 대한 사전 기대 및 이후 사용 경험과의 비교를 통해 기대 (불)일치 및 (불)만족 요인에 대한 연구를 수행하였다. 이를 위해 국내 C 대학교의 학생들을 대상으로 개방형 설문을 진행하고, 해당 응답을 질적 내용 분석을 통해 분석하여 네 가지 기대 일치 및 만족 요인과 세 가지 기대 불일치 및 불만족 요인을 도출하였다. 이후 결과를 바탕으로 학술적 및 교육적 시사점을 제공하였다.

• 한국축산시설환경학회지
• /
• 제6권2호
• /
• pp.97-104
• /
• 2000

This study was carried out to determine the effects of different weaning age on feeding performance and behaviour of piglets. Sixty crossbred(YLxD) litters of piglets were randomly alloted to be 15 pens with 4 piglets per pen and 5 pens per treatment by weaned at 14, 21, and 28 days. Pens were video-taped for 24 hours immediately at 7 weeks and 8 weeks of age. The piglets weaned at 14 and 21 days were significantly (P<0.05) much intake than piglets weaning at 28 days. The piglets weaning at 14 days were significantly lighter than piglets weaning at 14 and 21 days fro m2 weeks to 8 weeks age. However, feed conversion ration was significantly(P<0.05) improved according to late weaning days. Times spent engaged in Feeding, lying and walking were similar in piglets across weaning age. They also showed similar occurrence of drinking and agonistic behaviour at 7 weeks and 8 weeks of age. Piglets weaned at 14 days exhibited more belly-nosing behaviour at 7 weeks of age, but similar in piglets at 8 weeks of age across weaning age. We concluded that piglets performance influenced by weaning day, however time spent for feeding, lying and walking behaviour were no significance. Drinking, Agonistic and belly-nosing were not significantly different by weaning age.

• 한국가금학회지
• /
• 제38권4호
• /
• pp.305-313
• /
• 2011

계사 사육 형태에 따른 닭의 스트레스 정도를 알아보기 위하여 단관백색레그혼종을 대상으로 케이지 사육 및 평사 사육으로 관리 후 이들의 생산 능력과 스트레스 관련 표지를 비교 분석하였다. 개체의 생산 능력에 있어 생존율, 산란 지수, 난중 및 체중은 평사 사육군이 케이지 사육군에 비해 유의하게 높은 성적을 보였고, 반면 초산 일령 및 난질의 경우 케이지 사육군이 양호한 결과를 나타내었다. 사육 형태에 따른 닭의 스트레스 관련 표지로 형광접합보인법에 의한 텔로미어 함량 분석 및 comet assay에 의한 DNA 손상율을 비교 분석하였다. 텔로미어 함량 분석 결과, 혈액 세포 및 신장, 비장 세포의 경우 평사 사육군이 케이지 사육군에 비해 유의하게 높은 텔로미어 함유율을 보이고, 연령이 증가함에 따라 이의 차이는 더욱 커지는 것으로 나타났다. DNA 손상율은 케이지 사육군이 평사 사육군에 비해 유의하게 높은 손상율을 나타내어 케이지 사육이 평사 사육에 비해 훨씬 높은 스트레스 상태임을 알 수 있었다. 따라서 생존율을 포함한 생산 능력과 스트레스 표지 분석 결과, 산란계에 있어 케이지 사육 방식이 평사 사육 방식보다 개체들에게 생리적 스트레스 요인이 상대적으로 큰 것으로 사료된다.

• 한국축산시설환경학회지
• /
• 제4권1호
• /
• pp.9-20
• /
• 1998

This research was conducted to investigate the effects on the amount of nitrogen and phosphorus and the number of maggots in the feces from the experimental pigs fed probiotics additives, and the variance of NH3-concentration(ppm) generated in the experimental pig-pens. The experiment was performed twice in the W-farm(under the condition of sufficient energy and protein in Spring) and B-farm(insufficient energy and protein in Summer). The experiment was designed with 5 treatments (control and 4 treatments according to the kinds of additives used). In the W-farm experiment, 75 three-way crossbred pigs weighing average 38kg were randomized with 3 replications for 102 days. In the B-farm experiment, 105 three-way crossbred pigs weighing average 33kg were randomized with 3 replications for 130 days. The results obtained are as follows: 1. The amount of dry matter, organic matter, nitrogen and phosphorus in the feces was not significantly different among the treatments. But the amount of OM, N and P shows a tendency to be somewhat lowered in the treatment A. On the otherhand, the amount of dry matter was somewhat lowered in the treatment B. The amount of such matters in the W-farm was somewhat lowered than those in B-farm. But there was not significant difference between W-farm and B-farm. 2. On the variance of the number of maggots developed in the pig's feces according to each treatment, the number of maggots in the treatments added probiotics were markedly decreased in comparison with those of the control(T), and it was significantly different(p＜0.01). Especially the decrease in the treatment A and B was much remarkable. 3. The addition of probiotics to the pigs' feeds made the NH3-concentration generated in the pig-pens decrease markedly. especially the NH3-concentration in the treatment A had the highest decreasing ratio among all the treatments. The decreasing ratio of NH3-concentration of the treatments added probiotics as compared to control(T) was 59.1∼80.0%(average 70.3%) in the treatment A, 56.8∼80.0%(ave. 68.5%) in the treatment B and 24.4∼46.0%(ave. 35.0%) in the treatment C and D. On the variance of the NH3-concentration according to the experimental times)seasonal conditions), the NH3-concentration generated in the pig-pens was gradually increased from April to August, on the other hand it was decreased in the September. By the result of this study, it was appeared that the probiotics added to the pigs' feeds made the NH3-concentration decrease in the pig-pens to the extent of safety degree(25 ppm and less) permitted to swine especially in the treatment A and B.

• Asian-Australasian Journal of Animal Sciences
• /
• 제6권2호
• /
• pp.305-311
• /
• 1993

A total of thirty male Holstein calves were reared outdoors with simple housings or in warmed pens in three experiments conducted in three consecutive midwinters in Hokkaido. Average outdoor air temperatures during the experiments were between -5.3 and $-6.1^{\circ}C$, and average minimum air temperatures were between -9.7 and $-10.6^{\circ}C$. The age of calves at the start of the experiments were $16{\pm}6$ hours. There was no difference in the liquid feed intake, while the solid concentrate (artificial milk) intake by the calves in the simple housing systems (outdoors, calf hutch and open shed) tended to be higher than those in the warmed pen. No significant differences in the daily gain or the monthly development of wither height were observed among housing systems. There were no serious cases of diarrhea. However, coughing was observed in several of the calves reared in the poorly ventilated warmed pens.

• 한국가금학회지
• /
• 제25권2호
• /
• pp.65-70
• /
• 1998

A 16-wk feeding trial was conducted to investigate the proper feeding regimen on the performance of Korean Native Chicken(KNC) consuming broiler diets. Commercial KNC are normally fed 3 kinds of diets during their life span, i. e., starter(S, 0 to 3wk of age), grower(G, 4 to 7wk of age), and finisher(F, 8 to l6wk of age) diets. In this trial, four feeding regimen were employed:T1(S-G-F), T2(S-G-G), T3(S-S-F), and T4(S-F-F). Day-old 360 KNC were randomly allotted to 12 pens: three pens per treatment, and 30 birds per pen. At the end of the trial, the BW of T2 was significantly better than that of T3(P<0.05), and T1 and T4 were intermediate. No significant difference were found in feed intake, feed conversion ratio, and viability among treatments. It appears that, in terms of BW gain, the T2 is the recommendable feeding regimen for KNC consuming broiler diets.

• 한국어병학회지
• /
• 제1권2호
• /
• pp.111-116
• /
• 1988

There occurred a large quantity of death of the cultured carp (Cyprinus carpio) in net pens in Lake Taechong and Lake Chungju(Chungcheongbuk-do) from July through Sep., 1987. The carp were two-year-old and 500g to 2,500g in body weight. As a result of biopsy of dying carp, 1 through 10 egg-shaped giant cysts with 12 through 60mm in diameter were observed in their intestine per one carp. The author suggested that the carp were died from blockade of intestinal tract and following enteritis by the giant cysts. The giant cysts were filled with numerous mature Thelohanellus genus spores confirmed to Thelohanellus kitauei after following examination. In this case the author could find out this disease was spread by transverse infection following infestation in net pens of fingerling fish farms.

• 분석과학
• /
• 제17권4호
• /
• pp.315-321
• /
• 2004

The aim of this study was to investigate the evidential value of blue and black ballpoint pens on paper by nondestructive techniques. In this work, 21 blue and 22 black ballpoint pens which were purchased on different brands were analyzed by Raman Spectroscopy and Video Spectral Comparator (VSC). Surface-Enhanced Resonance Raman Spectroscopy (SERRS) with excitation at 685 nm and VSC with several spot light filters were used for the discrimination of ballpoint pen inks. In the SERR spectra, the ballpoint pen inks on paper could be shown sharp spectral bands and distinguished by their band shapes and relative intensities. In the blue and black ballpoint pen inks, the discriminating powers (DP) by SERRS were 0.85 and 0.67 and the DP by VSC were 0.88 and 0.90, respectively. The DP by combined sequence of techniques was all 0.97 in both black and blue ballpoint pen inks.