• The Korean Journal of Physiology
• /
• 제2권2호
• /
• pp.21-31
• /
• 1968

The appearance rates of antipyrine and urea into cerebrospinal fluid from blood were studied in the rabbits which were in the state of hypotension and of high permeability in the capillary beds following injection of histamine. The alteration in the distribution of electrolytes among various compartments of the brain and the permeability characteristics in the blood-cerebrospinal fluid barrier were also observed. Adult male rabbits, weighing around 2 kg, were used. Twenty four rabbits were divided into 3 groups. Besides the control group, histamine treated rabbits were categorized into 2 groups. $H_1$ consisted of the rabbits showing moderate responses to histamine and ranging from 62 to 80 mmHg in their mean anterial blood pressure. The animals which belong to $H_2-group$ showed severe responses to histamine and the mean anterial blood pressures dropped to 30-50 mmHg. Animals were anesthetized with nembutal, 30mg/kg i.v. The mean arterial blood pressure was read by means of the mercury manometer connected to the femoral artery. The animals, treated with histamine, were kept in hypotensive state at least for 40 minutes before the administration of the test-substances. The test-substances, 300 mg of urea and 200 mg of antipyrine, were dissolved in 3 ml of distilled water and were injected into the ear vein of the rabbit. After 10 minutes elapsed arterial blood sample was taken from the femoral artery and cerebrospinal fluid from the cisterna magna. Brain tissues were also analysed with respect to electrolytes in order to observe the disturbances in the electrolytes balance as well as in the function of the central nervous system. The results obtained were as follow: 1. The ratio of antipyrine concentration in cerebrospinal fluid to that of arterial blood plasma, that was the distribution ratio, was close to unity, revealing a well established equilibrium between the compartments of blood and cerebrospinal fluid in 10 minutes. In other words, there was no diffusion barrier with regard to antipyrine. The ratios over unity which were frequently seen in the histamine treated animals were attributable to the early penetration of the substance into the cerebrospinal fluid. 2. The appearance rates of urea into the cerebrospinal fluid in the histamine treated rabbits were higher in comparison with those of in the control animals. The increasing tendency in the rates was particularly remarkable in the $H_2-group$, showing the enhanced penetration of urea across the boondary. 3. In the htisamine treated $H_2-group$ the concentration of potassium in the blood plasma and cerebrospinal fluid well exceeded the control values and showed 8.5 and 9.0 mEq/l in average, respectively. Simultaneous drops in the brain tissue water were noticed, suggesting the leakage of intracellular potassium. 4. There was a coincidence in the rising pattern of potassium in the blood plasma and in the cerebrospinal fluid of $H_2-group$ and at least partial removal of the blood-cerebrospinal fluid barrier with respect to potassium was suggested in these animals. 5. The concentration of sodium in the blood plasma or in the cerebrospinal fluid showed no significant changes following histamine injection. However, sodium in the brain tissue revealed slight elevation in the histamine treated groups. 6. The ratios of the concentrations of potassium to those of sodium, [K]/[Na] in the brain tissues, were 1.92 in the control 1.82 in the $H_1$ and 1.52 in the $H_2-group$, respectively. The marked drop in the $H_2-group$ might represent neural dysfunction in the extremely hypotensive rabbits.

• 자원환경지질
• /
• 제2권3호
• /
• pp.1-25
• /
• 1969

In considering the mining industry, it is necessary to study the production, consumption and price of ore and metals in every country of the world in order to determine the trend of the industry in the present and for the future. This study is necessary especially for exporting domestically produced are which is in excess of domestic consumption and for importing are, or metal where local production does not meet domestic demand. It will be treated of Au, Ag, Cu, Pb, Zn, W, Mo, which are the most important non-ferrous metals, and which greatly affect the mining industry of Korea. The presentation will concern itself only with the free world. About 1, 200 ton of gold are produced annually with little fluctiation in recent years. Most of the gold produced is consumed by advanced countries for industrial uses as well as for producing precious objects. The U.S.A. expends yearly about four times its domestic production and Japan about three times its domestic production for industry and arts. Because of the instability of the currency of the U.S.A., England and France, recently, the price of gold has been $ 41-42 per ounce, whereas the official price is $35.00 per ounce. It will be expected that the official price will be raised in the near future. As for silver, about 6,500 tons are produced annually with no special fluctuation change in recent years. However, the annual consumption is about 14,000 ton, so the supply and demand is extremely unbalanced. The shortage is made up by the sale of the U.S. treasury's reserve stock and the reclaiminig of silver from coins and other scrap. As the Treasury'S reserves will be exhausted in a year or two, the price of silver which is $1. 64 per ounce, will go up drastically in about a year. As for copper, 5,257,000 ton's were mined in 1966. It's production is being increased about 5% annually. However, consumption exceeds production by about 100,000 ton a year. The recent Foreign refinery copper price in the U.S.A is $ 60 per pound. The supply of copper being insufficient to meet international demands, the price will go up and with no prospect of being lowered in the near future even with the slight annual increase in production. About 2,100,000 to 2,200,000 tons of lead are produced annually. Consumption exceeds production by about 50,000-60,000 tons annually. The current price of lead in New York is $ 155 per pound. As the supply of lead is internationally stable, It will be believed that there will be no significant change in its price in the near future. In 1967, 3,926,000 tons of Zinc were produced. There is annual increase of 4-7% in production. The annual consumption exceeds production by 100,000 to 200,000 tons. The current zinc price in the St. Louis market inthe U.S.A. is $ 145 per pound. Even though its supply is stable and sufficient world wide, the consumption rate will increase at a faster pace than before; hence, the price will slowly go up. Tungsten mines yield about 11,000 tons a year. Its production has been relatively constant in the past few years. The amount of its consumption increases slowly world wide, but in the free world· there has been a slight annual decrease. However, since Red China has not been exporting their tungsten to other countries for several months, the price on the London market of S.T.U. of $Wo_3$ has increased to $ 44~46. Should Red China begin to export actively again the price will drop to $ 40~42. In 1967, 56,000 tons of Molybdenum were produced. Production exceeds consumption by 200,000 -30,000 tons annually. The current price in the U.S.A. is $ 1.72 per Mo pound. Since the rate of production in the U.S.A. is on the increase with large amounts of ore reserve, the price of molubdenum should not go up.

• 조형예술학연구
• /
• 제3권
• /
• pp.145-177
• /
• 2001

The artist's interest has been captivated by ecological phenomena in Nature. Her keen captivation has then been focused into plastic art depicting the image of primitive life. The wide sweep of her work encompasses the totality of nature which consists of the human's subconscious power and imagination which she then portrays by organic images. These organic images are in contrast to scientific, mathematical and logical inference and consciousness. This research examines the character of the organic images in modern art by her analysis of some representative works by others. The image is an essential concept in the art which appeared in very different ways and in different perspectives. The image in the artwork appears to be the realistic expression until the early part of the 20th Century. Well into the 20th Century, it began being expressed in various ways such as combined images by imagination which is combined or rejected in the story of artwork. It also began being expressed by transferred images by changed original conditions. It is the main purpose of this research is to study of various expressions of organic images in the artwork of the Post-Modernism era. The character and meaning of organic image painting helps people to approach the human instinct more easily to find out the natural essence. It is also an objective of the organic image to tenderise our human sensibilities, thus helping us to regain vitality and recover our poor humanity in the barren wilderness of modern society. 'Life communion with nature' is a meeting point and common ground for Oriental Philosophy and organic image painting. Through this research, organic image painting is characterised in the four following ways : 1st) Organic image painting seeks regularity and perfection of outer shapes, in contrast to disordered and deformed nature, resulting in organic and biotic formalistic mode of plastic art. 2nd) Organic image painting seeks the formative. 3rd) Organic image painting pursues the priceless dignity of life by researching the formatted arrangement and figure, which contains primitive power of life. 4th) Organic image painting makes crystal clear the power of human and nature, which is a historic and biological phenomenon. This, in turn, exposes the humanistic view of the world from modern society best characterised in lost self-understanding, isolation and materialism. The representative organic image painting artists are Elizabeth Murray, Kusama Yayoi, and Niki do Saint Phalle. Elizabeth Murray used shaped canvas and a round construction of relief works. Kusama Yayoi used Automatistic expressionism originating from the realms of unconsciousness and which is represented by the mass and shape of a water drop. Niki do Saint Phalle shows the transcendence of universal life and anti-life to respect the dignity of life and the eco-friendliness relationship of human and nature in the post-modernism in art history. This is accomplished by surrealistic, symbolic, fantastic and humoristic expression. These three artists' works express the spirit of the organic image in contemporary art. It contains the stream of nature and life to seek not only the state of materialism in the reality, but also the harmonized world of nature and human which has almost lost the important meaning in modern times. Finally, this organic image is the plastic language of the majestic life. It is the romantic idea that the intimacy of nature and the universe and Surrealism, which emphasizes the unconsciousness , is the source of truth and spirit. Also it is influenced by primitive art and abstract art. According to this research, the subject 'Research About Organic Images' is not only an important element in the plastic arts from primitive society to the present, but is also fundamental to an true understanding of Post-Modernism.

• 대한수의학회지
• /
• 제1권1호
• /
• pp.53-53
• /
• 1961

본인등(本人等)은 1957년(年)에 외국(外國)으로부터 한국(韓國)에 도입(導入)된 가축(家畜)과 국내일부가축(國內一部家畜)에 대(對)한 Brucellosis를 혈청학적방법(血淸學的方法)(응집반응(凝集反應)에 의(依)한 조사성적결과(調査成績結果)를 발표(發表)한바 있거니와, 이후(以後) 국내가축(國內家畜)에서 집단적(集團的) 또는 산발적(散發的)인 가축(家畜) Brucellosis의 발생(發生)을 관찰(觀察)하였기에 제2보(第二報)로서 1956년(年) 부터 1959년(年)에 이르기까지 수입가축(輸入家畜)과 국내일부가축(國內一部家畜)에 대(對)하여 미국농림성(美國農林省) Brucellosis의 검사(檢査) 방법(方法)에 의(依)한 혈청학적(血淸學的) 검사성적(檢査成績)을 발표(發表)하는 바이다. 1. 1956년(年) 수입유우(輸入乳牛) 76두검사중(頭檢査中)에서 양성(陽性) 9두(頭)(11.84%)와 1956년(年) 및 1958년(年) 수입산양(輸入山羊) 1127두검사중(頭檢査中)에서 양성(陽性) 11두(頭)(0.98%)를 발견(發見)하였다. 2. 국내(國內) 일부도내유우중(一部道內乳牛中)에서 1956년(年)에는 108두검사중(頭檢査中) 양성(陽性) 10두(頭)(9.25%), 1957년(年)과 1958년(年)에는 계(計) 155두검사중(頭檢査中) 양성(陽性) 10두(頭)(6.45%), 1959년(年)에는 127두검사중(頭檢査中) 양성(陽性) 2두(頭)(1.57%)를 발견(發見)하였다. 3. 국내(國內) 일부도내산양(一部道內山羊)에는 1958년(年)과 1959년(年)에 423두검사중(頭檢査中) 양성(陽性) 5두(頭)(1.15%)을 적발(摘發)하였고 돈(豚)에서는 1958년(年)에 683두검사중(頭檢査中) 양성(陽性) 11두(頭)(1.61%)와 1959년(年)에 668두검사중(頭檢査中) 양성(陽性) 11두(頭)(1.64%)를 발견(發見)하였으며 한국역우(韓國役牛)에 있어서는 1959년(年) 1133두검사중(頭檢査中) 양성(陽性) 7두(頭)(0.62%)의 성적(成績)을 보았다. 4. 국립제주목장육우(國立濟州牧場肉牛)에서 1956년(年)7월(月)에 580두검사중(頭檢査中) 양성(陽性) 111두(頭)(19.13%)를 적발(摘發)하고 양성(陽性)및 응양군육우(凝陽群肉牛) 157두(頭)에 대(對)한 2차적검사(二次的檢査)을 1959년(年)10월(月) 실시(實施)한바 양성(陽性) 71두(頭)와 응양성(凝陽性) 47두(頭)의 집단적(集團的) 발생(發生)을 확인(確認)하였다. 5. 수천지장사육돈군에 Brusella suis로 인(因)한 발생(發生)을 1958년(年)12월(月)에 확인(確認)하고 7차(次)에 걸친 연장검사(延長檢査) 438두중(頭中)에서 양성(陽性) 122두(頭)(27.87%)가 적발(摘發)되었다. 6. 1956년(年) 수입유우중(輸入乳牛中) 강양성(强陽性) 유우(乳牛) No. 33 및 35에 대(對)한 연장검사성적(延長檢査成績)에서 2개월후(個月後)의 혈청가(血淸價)의 심(甚)한저하(低下)의 4개월후(個月後)의 다시 상승(上昇)되는 혈청가(血淸價)의 동요(動搖) 예(例)를 관찰(觀察)하였다.

• Journal of Plant Biology
• /
• 제3권2호
• /
• pp.6-18
• /
• 1960

The present experiments were designed in order to clarify the differences between the long and short styled plants and the transgressive gradition in the degree of dimorphism among the three heterostylous species of the Polygonus, P. japonica, F. esculentum, and P. senticosa, based on investigations regarding the floral structure, ecological and physiological traits, the results of which are summarized as follows: (1) P. japonica, although it exhibits typical dimorphism, has undergone so high a differentiation between long and short styled that its long styled individuals behave as if they were female; and short styled individuals as if male. In long-styled individuals, filament, anther, and pollen grains show signs of degeneration, most of the pollen being abortive. On the other hand, in short styled individuals, the filament, anther, and pollen grains have attained remarkable development; the pollen grians are large and fertile. In short-plant the fertilized flowers readily drop off in every stage of their embryo development. This species has completely lost the self-fertile property, which is characteristic of the non-dimorphic Polygonum genus. Although this specsei typically exhibits the physiological characteristics of the non-dimorphic Polygonum genus. Although this specisei typically exhibits the physiological characteristics of dimorphism in controlled pollination, the short-styled individuals bear no seed in nature, thus misleading taxonomists to idenfity the short-styled plant as male. 2) The morphological feature of the flower organ of P. senticosa obviously indicates definite dimorphism. Physiologically, however, no differentiation towards dimorphism was observed, the species still retaining, both in long and short-individuals, the self-fertile property common to the Polygonum genus. Elaborate examinations revealed that regardless of the modes of pollination, both fertiization and seed setting flourish, no differentiation betwen legitimate and illegitimate unions being recognizable. This sort of physiological property has not been observed in the investigations of other heterostylous plants. It is assumed that this species is differentiated structurally into dimorphism, but not yet physiologically. In nature, however, this plant would have more opportunities to be cross-pollinated, i.e., legitimately combined, than self-pollinated because of the development of two forms of flowers. 3) In terms of heterostylism, the F. esculentum just occupies the intermediate position between P. japonica and P. senticosa structurally, ecologically, and physiologically. Doescription of some of the physiological behavior of the plant will suffice to demonstrate the above facts. While P. japonica has completely lost its self-fertile property, P. senticosa still retains it wolly. In F. esculentum 2-6% of self-fertility is the result in illegitimate combination. There occur occasionally hereditary self fertile individuals among some of the F. or 20 min. irradiation plot, when they reach any stage of the same bacterial population. In addition to this increase of total population in the plots with the more dose of UV light irradiation, it seems that the more dose of UV light irradiation is the more shortened the generation time of Azotobacter. Therefore, it is clear that variation of reproductive rate must be, mere or less, due to the genetic effects induced by UV light irradiation. On the other hand, the lag phase or logarithmic growth phase in nonirradiated culture is shortened prominently, and this must be due to the difference in bacterial number of the original inoculm. The generation time of Azotobacter is shortened by exogeneous treatment of nuclei acid derivatives, and the degree is greater in case of DNA derivatives than RNA dervatives. W.H. Price reported that the rate of ribose nucleic acid to protein in Staphylococcus muscae is proportional to the generation time: that is the faster the cell can form ribose nucleic acid, the more rapid its growth. This explains the shortening of generation time by exogeneous RNA derivatives in this work reasonably. On the other hand, it is well known that the desoxyribose nuclic acid content per cell is constant and independent of the generation time. A.D. Laren and W.N. Takahashi reported that the infectious RNA from TMV is 6 times as sensitive to inactivation by UV as it is in the form of intact virus, and that inactivation of infectious TMV involves onlu a local change on RNA chain. But, the effect of exogeneous DNA in this work suggests that irradiated living cell which cotain DNA bring about some change on DNA moleculs as well as RNA molecules. And if the mutagenic effects of UV take into consideration, it is very reasonable. Therefore, it is clear that the variation of the generation time by UV irradiation is, more or less, due to the genetic effects. Therefore, it seems that the shortness of the average lifewpan of Azotobacter by UV irradiation is resulted not only from the influence of the environmental conditions, but also from the variation of genetic factor of the individual.

• 자연과학논문집
• /
• 제1권
• /
• pp.115-198
• /
• 1987

The present studies were undertaken to elucidate the influence of auxins, auxin-like substance-ethychlozate ("Figaron"),and pH and sort of rooting media on rooted propagation of certainornamental woody plant cuttings, and to see possible changes in internal compositions characterizing after root-promoting treatment as the cutting stage proceeded. The experimental check-up srevealed and summarized as seen in the following;I. Effect of three different auxin treatments on rooting cuttings: 1) Promotive influence of auxin varied according to different concentration levels, hours of dipping treatment of the auxins, and kind of plants. The greatest effect was obtained for Forsythia ksreana with NAA and IBA, for Ligustrurn obtusifolium var. variegatum with NAA and ethychlozate, for Hydrangea macrophylla, Magnolia kobus, and Magnolia liliflora with NAA, lBA and ethychlozate also. The most effective level of the promotive agents was found 200mg/l for NAA, 1000mg/l for IBA, and 200mg/l for ethychlozate. For Weigela florida and Gardenia jasminoides, range of the most effective level was shown relatively wide spread. 2) NAA was more effective at its optimal level of the rooting agent than ethychiozate for Weigela florida, Viburnum awabuki, Forsythia koreana, Acer palmatum 'Nomura', Bouga invillea glabra, Elaeagnus umbellata, Prunus tomentosa, Ligustrum obtusifolium, Pyracantha coccinea, Cestrum noctu rnum, Hydrangea macrophylla, Codiaeum variegatum, Rhododen dron lateritium, and Ilex crenata var. macrophylla, and yet ethychlozate was found either as equally as effective or more so than NAA for Zebrina pendula, Hibiscus syriacus, Fatshedera lizei, Schefflera arboricola, Campsis grandiflo ra, Ixora chinensis, Euonymus japonica, and Magnolia liliflora. On the contrary, no the auxin effect was noted with Lagerstroemia indica, Trachelospermum asiaticum, and Syringa vulgaris. This probably indicates that these species are genetically different for the auxin response.II. Effect of different pH and sorts of cutting media on rooting cuttings: 1) Bougainvillea showed best in rooting for the number and dry weight at pH 6.5, more with ethychlozate than NAA, while Ligustrum did at pH 5.0 more with NAA than ethychlozate. pH 4.0 medium resulted in the best rooting for Rhododendron with NAA, more than ethychlozate. 2) Use of cutting medium with peat: perlite: vermiculite = 1:1:1 showed to give the greatest rooting percent and dry weight, apart from considering the number of roots. This apparently meant the fact that cutting medium has more to do with root growth than root differentiation. Rhododendron yet showed results with cutting media that use of peat: perlite = 2:1 mixed is more effective on rooting than using peat alone.III. Effect of auxinic treatments on rooting cuttings and change in some cutting compositions: 1) Under the climatic conditions of July having temperature $26.3\pm$$2.4^{\circ}C$for cutting bed, new roots of Magnolia started to show up generally 20 days after the cutting was made, whereas Cestrum did much earlier than that, namely 14 days after. 2) Although total carbohydrate content of Magnolia cuttings showed no marked change without auxin treatment, it did so with the treatment, especially 30 days after the start of cutting. Cestrum cuttings demonstrated a gradual in crease in total carbohydrate content as rooting took place, and the content became reduced more with auxin than with out, just about when rooting proceeded to 14 days after the start of cutting. 3) Magnolia generally showed an increase in total nitrogen content as rooting proceeded more, and Cestrum showed a decrease in total nitrogen of cuttings. The auxin treatment exhibited no pertinent relation with change in plant nitro gen when rooting is promoted with auxin treatment. 4) An abrupt drop of total sugar and reducing sugar was noticed as Magnolia rooting started, and this reduction was parti cularly outstanding with auxin treatment. Starch content also was decreased in the later stage of cutting with auxin treatment, and was rather increased without auxin. Although sugar content soon increased as cutting started with auxin treatment in the case of Cestrum, it became reduced after rooting took place. 5) Total phenol content increased with rooting, and this was especially true when rooting started. This increase was reversed somehow regardless of auxin treatment. A decrease in phenol of Magnolia was found more striking with auxin than without in the later stage of the cutting period. 6)Avena coleoptile test for auxin-like substances presented the physiologically active factor is more in easy-to-root Magnolia liliflora than hard-to-root Magnolia kobus, and the activity of auxin-like substances was much increased with auxin treatment. The increase in the growth promoting substances was markedly pronounced when rooting just started. The active growth substances decreased in the later stage of cutting, and certain inhibitory substances started appearing. Cestrum also showed physiologically similar growth promoting substances accompanying auxin-like active substances if auxin is treated, and some strong inhibitory substances seemed to appear in the later stage of cutting. 7) Mung-bean-rooting test indicated biologically that endogenous growth substances in Magnolia all promoted mung-bean rooting, and activity of the growth substances apparently stimulated mung-bean rooting with auxin more than without. Here auxin treatment seemed to give a rise to an increased activity of endogenous growth substances in cuttings. This activity was found much greater with either NAA or IBA than ethychlozate, and showed its peak of the activity when rooting first started taking place. Certain inhibitory substances for Avena coleoptile growth strongly promoted mung-bean rooting, and it was also much like in the case of Cestrum.

• 한국가축번식학회지
• /
• 제26권3호
• /
• pp.245-252
• /
• 2002

본 연구는 체세포 핵치환에 탈핵 후 통격한 소미수정란을 사용함에 있어서, MVC 초자화 동결방법과 탈핵난자의 활성화시기가 융해 후 생존율과 핵치환 이후 체외 발달에 미치는 영향을 조사하고자 실시하였다. 체외에서 20시간 동안 체외성숙된 소 미수정란은 수핵란으로 사용하기 위하여 5$\mu\textrm{g}$/$m\ell$ hoechst 처리 후, 형광현미경하에서 핵을 제거하였다. 본 실험은 세 그룹으로 나누어 실행되었다 Group I은 동결하지 않고 핵치환을 한 대조군이며, group III와 group II는 핵이 제거된 난자를 MVC 방법으로 동결하기 전과 후에 활성화 처리 (5$\mu\textrm{m}$의 ionomycin에 의해서 5분간 처리) 한 군이다. 초자화 동결을 위해서는 group II와 group III의 탈핵란은 EG10에서 5~10분간 전처리하고 EG30에서 30초간 노출하여 액체 질소에 침지하였다. 융해는 37$^{\circ}C$에서 4단계로 이루어졌다. 실험군은 모두 소 귀세포를 이용하여 핵치환을 실시하였으며, 전핵을 유도하기 위한 활성화를 위해서는 10$\mu\textrm{g}$/$m\ell$ cycloheximide와 2.5$\mu\textrm{g}$/$m\ell$ cytochalasin D)가 첨가된 CRlaa 배양액에서 1시간, 이후 10 $\mu\textrm{g}$/$m\ell$ cycloheximide가 들어있는 CRlaa 배양액에서 4시간동안 배양하였다. 활성화 처리가 끝난 난자들은 CRlaa 배양액에서 2일간 배양하여 난할이 유도된 난자만을 선별하여 난구세포와 7일 동안 공배양하였다. 동결 융해 이후 group II와 group III의 탈핵된 소 미수정란의 체외 생존율은 81.0%와 84.9%로 유의적인 차이가 없었다. 체세포와 수핵란과의 융합율도 각각 69.0%와 70.0%로 대조군 (75.2%) 과도 유의적인 차이를 나타내지 않았다. 난할율은 53.4%와 58.4%로 group II와 group III간에 유의적인 차이를 나타내지 않았지만 group II의 분할된 세포질을 가진 이상난자의 비율이 group III보다 유의하게 높게 나타났다 (P<0.05). 또한, morula 이상으로 발달율도 group II (8.6%) 에서 group III (15.6%)보다 낮은 결과를 얻었다 하지 만 group III (15.6%)의 체외 발달율은 대조군 (24.8%)과 유의한 차이를 없었다. 따라서, MVC 동결 방법은 탈핵된 소 미수정란을 동결하기에 적합한 방법이며, 탈핵 후 activation을 유도하고 초자화 동결한 난자는 동결하지 않은 신선란과 동일하게 체세포 핵치환에 유용하게 이용될 수 있으리라 사료된다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제13권11호
• /
• pp.1619-1637
• /
• 2000

A review was undertaken to obtain information on the range of beak-trimming methods available or under development. Beak-trimming of commercial layer replacement pullets is a common yet critical management tool that can affect the performance for the life of the flock. The most obvious advantage of beak-trimming is a reduction in cannibalism although the extent of the reduction in cannibalism depends on the strain, season, and type of housing, flock health and other factors. Beak-trimming also improves feed conversion by reducing food wastage. A further advantage of beak-trimming is a reduction in the chronic stress associated with dominance interactions in the flock. Beak-trimming of birds at 7-10 days is favoured by Industry but research over last 10 years has shown that beak-trimming at day-old causes the least stress on birds and efforts are needed to encourage Industry to adopt the practice of beak-trimming birds at day-old. Proper beak-trimming can result in greatly improved layer performance but improper beak-trimming can ruin an other wise good flock of hens. Re-trimming is practiced in most flocks, although there are some flocks that only need one trimming. Given the continuing welfare scrutiny of using a hot blade to cut the beak, attempts have been made to develop more welfare friendly methods of beak-trimming. Despite the developments in design of hot blade beak-trimmers the process has remained largely unchanged. That is, a red-hot blade cuts and cauterises the beak. The variables in the process are blade temperature, cauterisation time, operator ability, severity of trimming, age of trimming, strain of bird and beak length. This method of beak-trimming is still overwhelmingly favoured in Industry and there appears to be no other alternative procedures that are more effective. Sharp secateurs have been used trim the upper beak of both layers and turkeys. Bleeding from the upper mandible ceases shortly after the operation, and despite the regrowth of the beak a reduction of cannibalism has been reported. Very few differences have been noted between behaviour and production of the hot blade and cold blade cut chickens. This method has not been used on a large scale in Industry. There are anecdotal reports of cannibalism outbreaks in birds with regrown beaks. A robotic beak-trimming machine was developed in France, which permitted simultaneous, automated beak-trimming and vaccination of day-old chicks of up to 4,500 chickens per hour. Use of the machine was not successful because if the chicks were not loaded correctly they could drop off the line, receive excessive beak-trimming or very light trimming. Robotic beak-trimming was not effective if there was a variation in the weight or size of chickens. Capsaicin can cause degeneration of sensory nerves in mammals and decreases the rate of beak regrowth by its action on the sensory nerves. Capsaicin is a cheap, non-toxic substance that can be readily applied at the time of less severe beak-trimming. It suffers the disadvantage of causing an extreme burning sensation in operators who come in contact with the substance during its application to the bird. Methods of applying the substance to minimise the risk to operators of coming in contact with capsaicin need to be explored. A method was reported which cuts the beaks with a laser beam in day-old chickens. No details were provided on the type of laser used, or the severity of beak-trimming, but by 16 weeks the beaks of laser trimmed birds resembled the untrimmed beaks, but without the bill tip. Feather pecking and cannibalism during the laying period were highest among the laser trimmed hens. Currently laser machines are available that are transportable and research to investigate the effectiveness of beak-trimming using ablasive and coagulative lasers used in human medicine should be explored. Liquid nitrogen was used to declaw emu toes but was not effective. There was regrowth of the claws and the time and cost involved in the procedure limit the potential of using this process to beak-trim birds.

• 설비공학논문집
• /
• 제25권6호
• /
• pp.346-361
• /
• 2013

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2012. 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. The conclusions are as follows : (1) The research works on thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and valves, fuel cells and power plants, ground-coupled heat pumps, and general heat and mass transfer systems. Research issues are mainly focused on new and renewable energy systems, such as fuel cells, ocean thermal energy conversion power plants, and ground-coupled heat pump systems. (2) Research works on the heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer, and industrial heat exchangers. Researches on heat transfer characteristics included the results for natural convection in a square enclosure with two hot circular cylinders, non-uniform grooved tube considering tube expansion, single-tube annular baffle system, broadcasting LED light with ion wind generator, mechanical property and microstructure of SA213 P92 boiler pipe steel, and flat plate using multiple tripping wires. In the area of pool boiling and condensing heat transfer, researches on the design of a micro-channel heat exchanger for a heat pump, numerical simulation of a heat pump evaporator considering the pressure drop in the distributor and capillary tubes, critical heat flux on a thermoexcel-E enhanced surface, and the performance of a fin-and-tube condenser with non-uniform air distribution and different tube types were actively carried out. In the area of industrial heat exchangers, researches on a plate heat exchanger type dehumidifier, fin-tube heat exchanger, an electric circuit transient analogy model in a vertical closed loop ground heat exchanger, heat transfer characteristics of a double skin window for plant factory, a regenerative heat exchanger depending on its porous structure, and various types of plate heat exchangers were performed. (3) In the field of refrigeration, various studies were executed to improve refrigeration system performance, and to evaluate the applicability of alternative refrigerants and new components. Various topics were presented in the area of refrigeration cycle. Research issues mainly focused on the enhancement of the system performance. In the alternative refrigerant area, studies on CO2, R32/R152a mixture, and R1234yf were performed. Studies on the design and performance analysis of various compressors and evaporator were executed. (4) In building mechanical system research fields, twenty-nine studies were conducted to achieve effective design of mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, renewable energy systems, and lighting systems in buildings. New designs and performance tests using numerical methods and experiments provide useful information and key data, which can improve the energy efficiency of buildings. (5) In the fields of the architectural environment, studies for various purposes, such as indoor environment, building energy, and renewable energy were performed. In particular, building energy-related researches and renewable energy systems have been mainly studied, reflecting interests in global climate change, and efforts to reduce building energy consumption by government and architectural specialists. In addition, many researches have been conducted regarding indoor environments.

• International Journal of Computer Science & Network Security
• /
• 제21권12spc호
• /
• pp.664-674
• /
• 2021

The relevance of this scientific research is determined by the negative impact of the COVID-19 pandemic on the current trends and dynamics of world tourism development. This article aims to identify patterns of development of the modern tourist market, analysis of problems and prospects of development in the context of the COVID-19 pandemic. Materials and methods. General scientific methods and methods of research are used in the work: analysis, synthesis, comparison, analysis of statistical data. The analysis of the viewpoints of foreign and domestic authors on the research of the international tourist market allowed us to substantiate the actual directions of tourism development due to the influence of negative factors connected with the spread of a new coronavirus infection COVID-19. Economic-statistical, abstract-logical, and economic-mathematical methods of research were used during the process of study and data processing. Results. The analysis of the current state of the tourist market by world regions was carried out. It was found that tourism is one of the most affected sectors from COVID-19, as, by the end of 2020, the total number of tourist arrivals in the world decreased by 74% compared to the same period in 2019. The consequence of this decline was a loss of total global tourism revenues by the end of 2020, which equaled $1.3 trillion. 27% of all destinations are completely closed to international tourism. At the end of 2020, the economy of international tourism has shrunk by about 80%. In 2020 the world traveled 98 million fewer people (-83%) relative to the same period last year. Tourism was hit hardest by the pandemic in the Asia-Pacific region, where travel restrictions are as strict as possible. International arrivals in this region fell by 84% (300 million). The Middle East and Africa recorded declines of 75 and 70 percent. Despite a small and short-lived recovery in the summer of 2020, Europe lost 71% of the tourist flow, with the European continent recording the largest drop in absolute terms compared with 2019, 500 million. In North and South America, foreign arrivals declined. It is revealed that a significant decrease in tourist flows leads to a massive loss of jobs, a sharp decline in foreign exchange earnings and taxes, which limits the ability of states to support the tourism industry. Three possible scenarios of exit of the tourist industry from the crisis, reflecting the most probable changes of monthly tourist flows, are considered. The characteristics of respondents from Ukraine, Germany, and the USA and their attitude to travel depending on gender, age, education level, professional status, and monthly income are presented. About 57% of respondents from Ukraine, Poland, and the United States were planning a tourist trip in 2021. Note that people with higher or secondary education were more willing to plan such a trip. The results of the empirical study confirm that interest in domestic tourism has increased significantly in 2021. The regression model of dependence of the number of domestic tourist trips on the example of Ukraine with time tendency (t) and seasonal variations (Turˆt = 7288,498 - 20,58t - 410,88∑5) it forecast for 2020, which allows stabilizing the process of tourist trips after the pandemic to use this model to forecast for any country. Discussion. We should emphasize the seriousness of the COVID-19 pandemic and the fact that many experts and scientists believe in the long-term recovery of the tourism industry. In our opinion, the governments of the countries need to refocus on domestic tourism and deal with infrastructure development, search for new niches, formats, formation of new package deals in new - domestic - segment (new products' development (tourist routes, exhibitions, sightseeing programs, special rehabilitation programs after COVID) -19 in sanatoriums, etc.); creation of individual offers for different target audiences). Conclusions. Thus, the identified trends are associated with a decrease in the number of tourist flows, the negative impact of the pandemic on employment and income from tourism activities. International tourism needs two to four years before it returns to the level of 2019.