• Proceedings of the KWS Conference
• /
• 2004.05a
• /
• pp.232-233
• /
• 2004

강구조물 제작 시 용접프로세스에 의해 용접부 근방에 불균일한 온도분포가 발생하여 용접변형이 발생된다. 이러한 용접변형은 좌굴강도와 피로강도를 저하시킬 뿐 아니라 구조물의 크기와 형상을 변화시켜 이를 교정하거나 수정하기 위해 추가작업을 실시해야함으로 생산성을 저하시키는 주요한 요인이 되고 있다. (중략)

• Journal of the korean veterinary medical association
• /
• v.43 no.6
• /
• pp.526-535
• /
• 2007

부신피질기능항진증(HAC)과 갑상선기능저하증은 개에 있어 가장 일반적인 호르몬 질환이라고 할수있다. 정확한 진단을하고 가장 알맞은 검사 방법을 선택하기 위해서는 각 진단방법과 그에 대한 한계점을 명확히 알아야 할 것이다. 다음은 임상 증상에 따라 단계적으로 적용할수있는 호르몬 진단법에 대한 소개로써 복잡한 호르몬 질환에 대한 이해에 도움이 될 것으로 생각된다.

• KOREAN POULTRY JOURNAL
• /
• v.38 no.5 s.439
• /
• pp.99-101
• /
• 2006

지난 3월 충남육계연합회 정기회의 석상에서 육계 생산성 저하문제가 1차적으로 거론되면서 대다수의 육계농가에서는 출하율이 저조한 점에 대해 생산자들은 어떤 입장을 보이고 있는지 들어보았다. 특히 전라남도와 충남 지역의 생산성이 저조한 것으로 나타났고, 이종수 논산지부장을 포함한 이희무 감사, 정운광 총무, 한채령 여사를 만나 논산 육계생산의 현 실태와 앞으로의 대책 방안 및 건의사항에 대해 들어보았다.

• Feed Journal
• /
• v.2 no.6
• /
• pp.92-95
• /
• 2004

푸르른 실록의 5월이 지나 6월에 접어들면 우리나라의 경우 더위의 시작과 장마가 찾아오는 시기로 접어든다. 덥고 습윤한 환경은 우리 인간 뿐만 아니라 가축에게도 스트레스를 주고 생산성 저하를 유발시키고 경제적인 손실을 준다. 특히 착유우에 있어 덥고 다습한 환경은 체유지와 유생산을 위한 영양소의 섭취를 저해시키는 요인으로 작용하고 있다. (중략)

• KOREAN POULTRY JOURNAL
• /
• v.24 no.9 s.275
• /
• pp.166-169
• /
• 1992

닭의 바이러스성 간염은 닭에서 흔히 일어나는 질병 중의 하나는 아니다. 그러나 국내에서는 본질병의 전형적인 발생 예가 아직 검색되지 않았으나 외국의 대군사육계군에서 종종 발생하고 있어 국내에도 최근 대군사육화하면서 우려가 되는 질병으로 그중 스트레스에 의한 간염이 때때로 상당한 생산성 저하를 유발하기도 하며 산란율과 폐사율에서 경제적인 손상을 미치게하는 스트레스에 의해 발병이 가중되는 바이러스성 간염이 양계장 생산성에 미치는 영향에 대해 알아보고자 한다.

• The Journal of Engineering Geology
• /
• v.12 no.1
• /
• pp.95-109
• /
• 2002

A significant question is what role does newly-formed expansive mineral growth play in the premature deterioration of concrete. These minerals formed in cement paste as a result of chemical reactions involving cement paste and coarse/fine aggregate. Petrographic observations and SEM/EDAX analysis were conducted in order to determine chemical and mineralogical changes in the aggregate and cement paste of samples taken from lowa concrete highways that showed premature deterioration. Formation and expansive mechanisms involved in deterioration were Investigated. Brucite, Mg(OH)$_2$, is potentially expansive mineral that farms in cement paste of concretes containing reactive dolomite aggregate as a result of partial dedolomitization of the aggregate. No cracking was observed to be spatially associated with brucite, but most brucite was microscopic in size and widely disseminated in the cement paste of less durable concretes. Expansion stresses associated with its growth at innumerable microlocations may be retrieved by cracking at weaker locations in the concrete. Ettringite, 3CaO.Al$_2$O$_3$.3CaSO$_4$.32$H_2O$, completely fills many small voids and occurs as rims lining the margin of larger voids. Microscopic ettringite is common disseminated throughout the paste in many samples. Severe cracking of cement paste causing premature deterioration is often closely associated with ettringite locations, and strongly suggests that ettringite contributed to deterioration. Pyrite, FeS2, is commonly present in coarse/fine aggregates, and its oxidation products is observed in many concrete samples. Pyrite oxidation provides sulfate ions for ettringite formation.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.26 no.3
• /
• pp.486-491
• /
• 1999

Hypoparathyroidism has abnormally decreased secretion of parathyroid hormon which responds to the blood calcium level. Wherease, Pseudohypoparathyroidism has normal activity of thyroid hormon, but end-organs, such as urinary tract and osteoclast, do not respond to parathyroid hormon. The cause of this disease is due to the mutation of Guanine stimulating(Gs) protein regulating Gs gene, which is the receptor to this hormon. Pseudohypoparathyroidism is usually noted before 20 years old on average of 8-9 years old. The clinical features of this disease includes delayed growth and development, round face, obesity, soft tissue calcification, ectopic ossification, shortening of metacarpals and metatarsals by epiphyseal closure in advance of age. The mutation of Gs gene which are found in brain, endocrine organs, and chondrocytes is the cause of those features. Reaction to Glucagon, gonadal hormon, and thyroid stimulating hormon is not expected in both cases. The common dental manifestations include enamel hypoplasia, delayed eruption, agenesis of tooth, hypodontia, dysplastic short roots, widened pulpal space, microdontia, intrapulpal calcification, and malocclusion are also often reported. This case which is diagnosed to Pseudohypoparathyroidism showed short and under-developed root of permanent troth, delayed eruption, and non-eruption of premolars and molars. And morphogenesis imperfecta of first and second premolars were also found.

• Journal of Bio-Environment Control
• /
• v.5 no.1
• /
• pp.65-70
• /
• 1996

Water potential which is an physical chemistry and thermodynamic indicator expressed water status of plant root, stem and fruit could be use as a useful indicator for growth control of hydroponically grown muskmelon plant. Linear relationship was observed between EC and water potential of nutrient solution, consequently increment of EC related to the decreasing water potential and resulted with the alteration of water potential and solute potential of upper leaves. Rapid reduction in growth was observed in over 5${\mu}{\textrm}{m}$ of Cu concentration in the media and same tendency was recorded in the shoot fresh weight, root dry weight and chlorophyll content. Increment of Cu concentration in the nutrient solution leads to lower the growth rate and then the water potential of upper leaves. Turgor pressure was not affected the growth of hydroponically grown muskmelon and also Cu concentration of nutrient solution was not recognized the direct relationship to the growth characteristics of muskmelon. These results demonstrated that water potential of nutrient solution can be use as an useful indicator for water physiological comparison of plant growth in hydroponically grown muskmelon.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.6
• /
• pp.806-811
• /
• 2003

Effects of pH, temperature, light, sugars, organic acids, metal ions, ascorbic acid, thiamine nicotinic acid and pyridoxine on the stability of the color of the cranberry solution were investigated. The pH had marked influences on the color of the cranberry solution: i.e., the color of the cranberry solution was more intense at low pH. It showed characteristic bathochromic shift as the pH of the solution increased. The half-lives of olor value were 34 days at 37$^{\circ}C$, 91 mins at 9$0^{\circ}C$ and 29 mins at 12$0^{\circ}C$. Light gave an adverse effect to the stability of the color. The color degradation can be minimized by shielding the light from the cranberry solution. Among the sugars tested, fructose was the most deleterious followed by sucrose, galactose, maltose and glucose. Fumaric acid was found to be the most effective in stabilizing the color followed by citric acid, malic acid, acetic acid, while tartaric acid was found to be deleterious. Among the metal ions tested N $a^{+}$ and $Mg^{2+}$ were found to be effective in stabilizing the color, while M $n^{2+}$ was found to be the most deleterious followed by F $e^{2+}$, $K^{+}$ and $Ca^{2+}$. Ascorbic acid was found to be deleterious considerably followed by thiamine, while nicotinic acid and pyridoxine were found to be effective in stabilizing the color feebly.or feebly.

• Economic and Environmental Geology
• /
• v.36 no.5
• /
• pp.365-374
• /
• 2003

Various deleterious chemicals can be introduced to existing concrete structures from various external sources. The deterioration of concrete by seawater attack is involved in complex processes due to various elements contained in seawater. In the present study, attention was paid to the formation of secondary minerals and characteristics of mineralogical and micro-structural changes involved in concrete deterioration caused by the influence of major seawater composition. The characteristics of deterioration occurred in existing concrete structures was carefully observed and samples were collected at many locations of coastal areas in Busan-Kyungnam. The petrographic, XRD, SEM/EDAX analyses were conducted to determine chemical, mineralogical and micro-structural changes in the aggregate and cement paste of samples. The experimental concrete deteriorations were performed using various chloride solutions (NaCl, CaCl, $MgCl_2$ and $Na_2SO_4$ solution. The experimental results were compared with the observation results in order to determine the effect of major elements in seawater on the deterioration. The alkalies in seawater appear to accelerate alkali-silica reaction (ASR). The gel formed by ASR is alkali-calcium-silica gel which known to cause severe expansion and cracking in concrete. Carbonation causes the formation of abundant less-cementitious calcite and weaken the cement paste. Progressive carbonation significantly affects on the composition and stability of some secondary minerals. Abundant gypsum generally occurs in concretes subjected to significant carbonation, but thaumasite ({$Ca_6/[Si(OH)_6]_2{\cdot}24H_2O$}${\cdot}[(SO_4)_2]{\cdot}[(CO_3))2]$) occurs as ettringite-thaumasite solid solution in concretes subjected to less significant carbonation. Experimentally, ettringite can be transformed to trichloroaluminate or decomposed by chloride ingress under controlled pH conditions. Mg ions in seawater cause cement paste deterioration by forming non-cementitious brucite and magnesium silicate hydrate (MSH).