• Title, Summary, Keyword: Sound characteristics

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Management and Recycling of the Animal Fat Residue (동물성 지방의 재활용 방안에 관한 연구)

  • Kim, Nam-Cheon;Lee, Si-Jin;Shin, Hang-Sik;Song, Young-Chae
    • Journal of the Korea Organic Resources Recycling Association
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    • v.1 no.2
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    • pp.287-298
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    • 1993
  • In this study, generation characteristics and distribution situation of the animal fat residue were investigated to identify it's management problems and to propose alternatives for the recycling and final disposal. Generation sources were the meat distribution net-work including about 170 slaughterhouses, 280 meat-packing plants, thousands of meat shops and restaurants etc. The daily total amount of the animal fat residue is about 700 ton/day. More than 60% of the generation sources were concentrated in Seoul metropolitan area. The residue was collected by about 300 men using old-fashioned devices like handcarts, bike and auto bike, transported to the recycling plants by about 60 collection agencies. The residue was processed to produce by-products such as grease, tallow, animal feed ingredient in the recycling plants. At present, however, a great number of unlicensed, and mostly small rendering processors without having pollution control facilities do the unlawful business. These small, old fashioned and unorganized businesses are creating environmental problems by disposing the waste in improper ways such as open burning and dump. Improvement of the distribution network, the large-scale plants, and the estabilishing proper infrastructures were suggested to overcome the problems for the sound fat residues reprocessing industry.

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Flowering Characteristics and Acorn Production of Quercus auta Thunb. in Wando Island, Korea (완도지역 붉가시나무의 개화특성과 종실생산)

  • Park, In-Hyeop;Kim, So-Dam;Park, Jong-Won;Chae, Kyung-Seog;Kim, Gab-Tae;Um, Tae-Won
    • Korean Journal of Environment and Ecology
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    • v.28 no.3
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    • pp.326-330
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    • 2014
  • Flowering characteristics and acorn production of Quercus acuta were studied in a Quercus acuta forest at Wando island, Korea. Three sample trees were cut and measured to investigate flowering characteristics during flowering season. Eight $20m{\times}25m$ quadrats were set up and three $1m{\times}1m$ seed traps were established within each quadrat to investigate acorn production. There were no significant differences in number of female and male inflorescence per bearing shoot among crown positions, but these values decreased from the upper part to the lower part of crown. The number of female flowers was 5,025 flowers/tree, and of the total number, 60.3% was in the upper part, 28.4% was in the middle part and 11.3% was in the lower part of crown. The number of male flowers was 7,063 flowers/tree and increased from the lower part to the upper part of crown. Acorn production of total 24 seed traps was 947 acorns/$24m^2$, and of total acorn production, 11.0% was sound, 61.9% was damaged, 25.1% was decayed and 2.0% was empty. Monthly acorn production was 240 acorns/$24m^2$ in August, 632 acorns/$24m^2$ in September, 56 acorns/$24m^2$ in October, 17 acorns/$24m^2$ in November and 2 acorns/$24m^2$ in December. Acorns fallen in October showed higher mean length, diameter and weight than those of other months.

The Variation of Cone, Seed and Germination Characteristics of Picea jezoensis (Siebold & Zuccarini) Carriere Populations in Korea (한국산(韓國産) 가문비나무 자생집단(自生集團)의 구과(毬果), 종자(種子) 및 발아특성(發芽特性) 변이(變異))

  • Song, Jeong-Ho;Jang, Kyung-Hwan;Kim, Du-Hyun;Lim, Hyo-In
    • Korean Journal of Plant Resources
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    • v.24 no.1
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    • pp.69-75
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    • 2011
  • This study was conducted to investigate the variation of cone, seed and germination characteristics among populations and among individuals within populations of Picea jezoensis(Siebold & Zuccarini) Carriere distributed in Korea. Cone collected from 25 trees in two natural populations(Mt. Jiri and Mt. Dokyu) and their thirteen cone and seed characteristics as well as three germination behaviors were analyzed. Statistical analysis showed significant differences among populations and among individuals within populations in 9 traits except for seed breadth, seed weight, index of seed wing and mean germination time. Generally, morphological variation of cone and seed wings from Mt. Jiri population has smaller and longer than those of Mt. Dokyu population. Percentage of sound seeds and Tetrazolium test from Mt. Jiri population showed 1.79 and 1.87 higher values than Mt. Dokyu population, respectively. The maximum germination percentage was obtained at the optimum temperature of $20^{\circ}C$ and in this case, mean germination time and germination rate showed 7.5 days and 2.9 ea./day, respectively. In seed germination behaviors, percentage(40.7%) and rate(0.90 ea./day) of germination in Mt. Jiri population were more higher and faster than those of Mt. Dokyu population(17.7%, 0.37 ea./day). According to correlation analysis, P. jezoensis populations with small restricted distribution may have been reduced because seed qualities were correlated with increased levels of inbreeding and disproportion flowering.

Effects of ultrasonic thawing on the physicochemical properties of frozen pork (주파수에 따른 초음파 해동처리가 냉동 돈육의 이화학적 특성에 미치는 효과)

  • Kim, Jinse;Park, Seok Ho;Choi, Dong Soo;Choi, Seung Ryul;Kim, Yong Hoon;Lee, Soo Jang;Park, Chun Wan;Han, Gui Jeung;Jo, Byeong-Gwan;Park, Jong Woo
    • Korean Journal of Food Preservation
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    • v.24 no.2
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    • pp.230-236
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    • 2017
  • This study was carried out to investigate the effects of ultrasonic thawing on physicochemical characteristics of frozen pork sirloin. To determine the velocity of an ultrasonic thawing machine, $-80^{\circ}C$ frozen pork sirloins were thawed using 132, 580, and 1,000 kHz ultrasonic thawing machines, and the physicochemical properties of pork sirloin thawed with $15^{\circ}C$ tap water and those using the ultrasonic thawing machines were compared. As a result, thawing speed by ultrasonic thawing was three times faster than that of tap water, but drip weight loss rate is increased by about 5% during ultrasonic thawing compared to that during thawing in tap water. However, biochemical properties, such as pH, volatile basic nitrogen, thiobarbituric acid, and total aerobic bacteria, were not improved by ultrasonic thawing. Hunter values, such as total color change and redness, improved slightly after 580 kHz ultrasonic thawing. The hardness and chewiness of the pork sirloin decreased significantly after 580 kHz ultrasonic thawing; however, springiness was not changed. These results indicate that ultrasonic thawing is faster than thawing in tap water, but the physicochemical characteristics of frozen pork sirloin was not significantly improve by ultrasonic sound.

Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2008 (설비공학 분야의 최근 연구 동향: 2008년 학회지 논문에 대한 종합적 고찰)

  • Han, Hwa-Taik;Choi, Chang-Ho;Lee, Dae-Young;Kim, Seo-Young;Kwon, Yong-Il;Choi, Jong-Min
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.12
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    • pp.715-732
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    • 2009
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2008. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends in thermal and fluid engineering have been surveyed in the categories of general fluid flow, fluid machinery and piping, new and renewable energy, and fire. Well-developed CFD technologies were widely applied in developing facilities and their systems. New research topics include fire, fuel cell, and solar energy. Research was mainly focused on flow distribution and optimization in the fields of fluid machinery and piping. Topics related to the development of fans and compressors had been popular, but were no longer investigated widely. Research papers on micro heat exchangers using nanofluids and micro pumps were also not presented during this period. There were some studies on thermal reliability and performance in the fields of new and renewable energy. Numerical simulations of smoke ventilation and the spread of fire were the main topics in the field of fire. (2) Research works on heat transfer presented in 2008 have been reviewed in the categories of heat transfer characteristics, industrial heat exchangers, and ground heat exchangers. Research on heat transfer characteristics included thermal transport in cryogenic vessels, dish solar collectors, radiative thermal reflectors, variable conductance heat pipes, and flow condensation and evaporation of refrigerants. In the area of industrial heat exchangers, examined are research on micro-channel plate heat exchangers, liquid cooled cold plates, fin-tube heat exchangers, and frost behavior of heat exchanger fins. Measurements on ground thermal conductivity and on the thermal diffusion characteristics of ground heat exchangers were reported. (3) In the field of refrigeration, many studies were presented on simultaneous heating and cooling heat pump systems. Switching between various operation modes and optimizing the refrigerant charge were considered in this research. Studies of heat pump systems using unutilized energy sources such as sewage water and river water were reported. Evaporative cooling was studied both theoretically and experimentally as a potential alternative to the conventional methods. (4) Research papers on building facilities have been reviewed and divided into studies on heat and cold sources, air conditioning and air cleaning, ventilation, automatic control of heat sources with piping systems, and sound reduction in hydraulic turbine dynamo rooms. In particular, considered were efficient and effective uses of energy resulting in reduced environmental pollution and operating costs. (5) In the field of building environments, many studies focused on health and comfort. Ventilation. system performance was considered to be important in improving indoor air conditions. Due to high oil prices, various tests were planned to examine building energy consumption and to cut life cycle costs.

A Study on Jeju High School Students' Health Perception and Health Promotion Behavior (제주지역 고등학생의 건강지각과 건강증진 행위에 관한 연구)

  • Kim, Ok-Sun;Choi, In-Sook
    • The Journal of Korean Society for School & Community Health Education
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    • v.3
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    • pp.79-110
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    • 2002
  • The purpose of this study was to provide basic data necessary for creating a more successful health enhancement program, health education and health policy which can enhance health management abilities and enable a healthy school life by examining relations between high school students' health perception, who are in early adolescence, and their health promotion behavior. The subjects in this study were 813 students from 8 high schools on Jeju Island. The collected data were analyzed with t-test and one-way ANOVA through questionnaires by researcher on the basis of advance research. The findings of this study were as belows : 1. When general characteristics were considered, health perception was more significantly affected by those who were boys, whose family income was on a higher level, who scored better in school, whose parents were more concerned about their children's health, and who had experiences of being hospitalized. Especially, the more parents were concerned about their children's health, the higher the child's self-confidence on health(p<.05), anxiety on health(p<.05), practicality on disease prevention(p<.05), self-confidence on future health(p<.01), health care ability(p<.01), and family roles on health(p<.05). The less parents were concerned about their children's health, the higher the child's anxiety on disease(p<.01) and uncertainty on future health(p<.01). 2. When students' health promotion behavior was concerned, in the area of Eating Habits, having regular meals(72.9%), moderate consumption of meat(89.7%) and a balanced diet(64%) were common, whereas having a regular breakfast(37.4%) and eating vegetables and fruits(43.6%) were rare. In the area of Exercise, all subareas such as exercising 3 or 4 times a week(76.7%), more than one hour of exercise at a time(74.9%), a short distance walk(51.8%), exercise within one hour after meals(87%), and whether wanning up or not(88.6%) were above average. In the area of Personal Hygiene, all subareas such as drinking boiled water(57.3%), washing hands after using the bathroom(71%), brushing teeth after eating(42.4%), washing up after going out(50.3%), and washing hair and taking a frequent bath(77.2%) were rare. In the area of Control of Personal Relations, consulting personal problems with family(78.7%) had a positive response, whereas meeting someone new(59.8%), maintaining sound relations with the opposite sex(47.3%), having respect for one's opinion(51.5%), and maintaining peaceful relations with people(58.4%) had rare negative results. In the area of Stress Management, not being competitive(69.4%), releasing problems(62.4%) and sleeping soundly(66.2%) were common, whereas having your own ways to relieve stress(46.8%) and having your own dreams and hopes(58.5%) were rare. 3. When general characteristics were considered, as far as relations of health promotion behavior were concerned, the boys were significantly different in the area of Eating Habits(p<0.01) and Exercise(p<0.01), and the girls were in the area of Personal Hygiene. As family economic status was high and parents were concerned about their children's health, the entire areas of health promotion behavior were significantly different. Whether or not they were hospitalized made no significant difference in statistics. 4. When their regions were considered, it comparing city to town, there was no statistically significant difference in health perception and relations of health promotion behavior according to general characteristics. As seen in the results above, high school students' level of health perception and level of practicing health promotion behavior were generally low. In conclusion, by enhancing health perception, a plan for activating health education, which can implement positive health promotion behavior, should be made.

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COMPARATIVE STUDY UPON THE CHARACTERISTICS OF WRITING BETWEEN THE PATIENTS WITH WRITING DISABILITIES AND NORMAL ELEMENTARY SCHOOL STUDENTS (쓰기 장애 환자와 정상 초등학교 학생의 쓰기 특성 비교)

  • Cho, Soo-Churl;Shin, Sung-Woong
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.12 no.1
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    • pp.51-70
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    • 2001
  • Characteristics of handwriting were investigated and compared between the patients with writing disabilities and normal elementary school pupils. Generally, the heights of the letters of the patients were significantly larger than those of normal children, and letters of the patients were more sparsely distributed than those of controls. The distance between the words were significantly reduced in the patients’ writings, which indicated that patients had much more problems of space-leaving than normal pupils. Letter heights differences were significant across all grades in the patients and normal controls. The heights of the letters decreased as they grew older, and the slope of the decrements were more steeper in normal girls(r=-0.45) than girls with writing disabilities(r=-0.16). Sex differences were found in the letter spacings in low grades(grades 1, 2), that is, the distances between the letters were significantly narrower in the male patients than normal boys in these grades, and the differences were almost indiscriminating in grades 3 through 5, and finally, in sixth grade, letter spacings were signifycantly broader in normal boys than male dysgraphics. In girls, letter spacings were significantly broader in the patients across all grades. These findings supports the hypothesis that male and female writings were qualitatively different and that distinct mechanisms served in boys and girls dysgraphics. Across all grades and sexes, spaces between the words of the patients were significantly broader than normal pupils, which suggested that space-leaving between the words was important in Korean writings. There was trend that letter spacings and word spacings decreased across grades, but in girls, no correlations between the letter spacings and grades were found. Correlation analyses revealed that letter heights and letter spacings had mild correlation(r=0.11-0.15), and that letter spacings and word spacings had robust correlation(r=0.99). Phonological errors were mostly found in last phoneme(Jong-seong), especially double-phoneme(ㄳ, ㄵ, ㄶ, ㄺ, ㄻ, ㄼ, ㄾ, ㄿ, ㅀ, ㅄ), and in the case the sound values changed due to assimilations of phonemes. Semantic errors were rare in both groups. Space-leaving errors were correlated with phonological errors, and more frequent in boys than girls. In conclusion, significant differences existed in the letter heights, letter spacings, word spacings, and frequencies of phonological errors and spaceleaving errors between the patients with writing disabilities and normal pupils. The characteristics of writings changed across grades and the developmental profiles were somewhat quantitatively different between the groups. The differences became obvious from the second-third grades.

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Characteristics of Micro-Particle Separation according to HRT Changes (HRT 변화에 따른 미세입자 분리 특성)

  • Ahn, Kwangho;Ahn, Jaehwan;Kim, I-Tae;Kim, Seoggu;Kang, Sungwon;Park, Eunzoo;Lee, Youngsup
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.12
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    • pp.937-942
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    • 2013
  • Fluid generated within the sonic or ultrasonic waves are reflected by the wall, while the opposite direction forming a predetermined sound wave to the acoustic standing wave is referred to. In this study, the frequency of 1.0 MHz and 2.0 MHz acoustic standing wave generation module is installed in a continuous particle separation device, the laminar flow of influent, taking into account the hydraulic retention time (HRT) in accordance with changes in particle separation characteristics investigated. Operation of a standing wave in the particle separation device about $1.3{\sim}2.8^{\circ}C$ temperature is increased, but did not significantly affect the formation of standing waves. During operation, the HRT 1 hr frequency 1.0 MHz 2 hr, 4 hr longer as the particle separation efficiency (turbidity) were 64.1%, 70.0%, 74.3% and, 2.0 MHz has 58.0%, respectively, depending on HRT, 61.8%, 70.7% in the respectively. That is, the same frequency, the HRT treatment efficiency is 10% or more, depending on differences in generation and, 1.0 MHz frequency, 2 hr, 2.0 MHz 4 hr at about 70% or more of the processing efficiency can be maintained. Frequency of 1.0 MHz and 2.0 MHz operation at the same time, as a result, HRT 1 hr, 2 hr, 4 hr particle separation efficiency of 63.8%, respectively, 70.6%, 77.6%, rather than the generation of standing waves appear continuous HRT is affecting a lot of particles to separate could know.

Clinical Assessment of Patients with Mandibular Condyle hypoplasia (하악 과두저형성증 환자의 임상적 평가)

  • Yi, Young-Chul;Cho, Bong-Hae;Ok, Soo-Min;Heo, Jun-Young;Kim, Kyung-Hee;Ahn, Young-Woo;Ko, Myung-Yun;Jeong, Sung-Hee
    • Journal of Oral Medicine and Pain
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    • v.38 no.2
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    • pp.175-185
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    • 2013
  • Objective : Condyle hypoplasia in temporomandibular joint(TMJ) is often observed in several radiographic views. Mandibular Condyle hypoplasia is frequently confused with osteoarthritis with bony changes in TMJ. This paper investigated clinical characteristics of mandibular condyle hypoplasia as compared with TMJ osteoarthritis. Material and method : 276 patients with TMD were taken clinical and radiological examination and were divided into study group, 189 patients diagnosed with mandibular condyle hypoplasia, and control group, 87 patients diagnosed with TMJ osteoarthritis. And clinical features(Onset, Overjet, Overbite, Noise, Locking, NAS of noise, LOM, pain, MCO, and site of diagnosis and pain)of the two groups were compared. Results : 1. Mandibular condyle hypoplasia and TMJ osteoarthritis were similar in many of the clinical features. 2. Mandibular condyle hypoplasia concordance rates of the radiographic diagnosis site and the pain site was significantly lower than TMJ osteoarthritis. 3. Bilateral mandibular condyle hypoplasia group had more occlusal discomfort, and clenching habits than unilateral mandibular condyle hypoplasia group. 4. Unilateral mandibular condyle hypoplasia group had more unilateral chewing habits and LOM than unilateral TMJ osteoarthritis group. Unilateral TMJ osteoarthritis group had more morning stiffness and higher concordance rates of the radiographic diagnosis site and the click sound site than unilateral mandibular condyle hypoplasia group. 5. Bilateral mandibular condyle hypoplasia group had more usual headaches and overjet than bilateral TMJ osteoarthritis group. Conclusion : Mandibular condyle hypoplasia has somewhat distinguishing clinical characteristics as compared with TMJ osteoarthritis.

Comparison of Agronomic Characteristics, Forage Production and Quality of Kenaf (Hongma 300), Maize (Kwangpyeongok) and Sorghum × Sudangrass Hybrids (Jumbo) in Middle Region of Korea (중부지역에서 케나프(홍마 300), 옥수수(광평옥) 및 수수×수단그라스 교잡종(점보)의 생육특성, 수량성 및 품질비교)

  • Hwang, Tae-Young;Ji, Hee Chung;Kim, Ki Yong;Lee, Sang-Hoon;Lee, Ki-Won;Choi, Gi Jun
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.35 no.2
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    • pp.152-158
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    • 2015
  • This study was conducted from 2013 to 2014 in the middle region of Korea to compare the agronomic characteristics, forage production, and quality of kenaf, maize, and a sorghum ${\times}$ sudangrass hybrid. The three crops used in this study were kenaf "Hongma 300," maize "Kwangpyeongok," and the sorghum ${\times}$ sudangrass hybrid "Jumbo" (headless type). The sugar contents of the kenaf, maize, and sorghum ${\times}$ sudangrass hybrid were 5.4%, 4.4%, and 2.5%, respectively. The emergence rates and lodgings of the three crops were sound, as they were more than 80% and 1.5, respectively. The fresh yields of kenaf, maize, and the sorghum ${\times}$ sudangrass hybrid were 117,521 kg/ha, 73,336 kg/ha, and 133,334 kg/ha, respectively, and the dry matter (DM) yields were 28,598 kg/ha, 19,951 kg/ha and 20,083 kg/ha, respectively. The DM yield of kenaf was significantly the highest among the three crops (p<0.05). However, the total digestible nutrients (TDN) contents of the kenaf, corn, and sorghum ${\times}$ sudangrass hybrid were 43.3 %, 72.0 %, and 54.8 %, respectively, and the in vitro digestible dry matter (IVDDM) yields were 44.4%, 73.7%, and 59.6 %, respectively; therefore, the TDN yield of the corn was 13 % significantly higher than that of the kenaf (p<0.05). The TDN yields of the kenaf, corn, and sorghum ${\times}$ sudangrass hybrid were 12,472 kg/ha, 14,350 kg/ha, and 11,001 kg/ha, respectively. Among the three crops, the content of neutral detergent fiber (NDF) and acid detergent fiber (ADF) were highest in the kenaf. This study shows that the kenaf had a good forage productivity but a low forage quality.