The moisture and dimensional behaviors of a nail-laminated timber (NLT)-concrete slab composed of an NLT-plywood composite and topping concrete are monitored for 385 days. The slab is developed for using as flexural elements such as floors. The humidity control of wood gently introduces significant fluctuations under the ambient relative humidity into the slab, and fluctuations in the relative humidity result in dimensional changes. The equilibrium moisture content of the slab increases from 6.7% to 15.3% during the monitoring period, resulting in a width (radial) strain of 0.58%. The length (longitudinal) strain is negligible, and the height (tangential) strain is excluded from the analysis because of abstruse signal patterns generated. Concrete pouring causes a permanent increase in the width of the NLT-plywood composite. However, the width deforms because the weight of the concrete mixture loosens the nail-laminated structure, not because of the significant amount of moisture in the mixture. The dimensional stabilization effect of the nail-laminated system is demonstrated as the composite strain is lower than the total strain of lumber and plywood, which are elements constituting the nail-laminated structure.
Journal of the Korea institute for structural maintenance and inspection
/
v.13
no.2
s.54
/
pp.199-205
/
2009
Recently, as the concern for the development of a construction method for an environmental protection and for tall building is increasing, the use of the half precast concrete(PC) slab that has the solution of environmental problems and the advantage such as reduction of construction period is being demanded. However, there is shortcoming that the crack can occur easily while constructing, and these cracks can have a bad influence upon the structural performance of PC composite slab. However, there is little studies on the influence of these cracks on the structural performance of composite PC slab. In this study, the specimen caused the crack before pouring topping concrete in the half PC slab and the PC composite slab without the cracks were produced to investigate the structural performance of PC composite slab with crack.
Some substances and freezing tolerance in the mulberry (Morus species) branch have been studied on the basis of varietal differences and harvesting times along with harvesting methods in autumn. The results obtained are summarized as follows; 1. The highest freezing tolerance was shown in the varieties of Yongcheon-chou, Jasan, Kang-weon No. 3 and Ichihei, the medium in Roso. Kairyonezumigaeshi, Yanagida and Kokuso No. 28, and the lowest in Ichinose, Mokuso, Kokuso No. 21 and Suweousang No. 3. 2. There was a signifiant negative correlation (r= -0.59*) between death atop percentage in the field and the temperature required to kill 50% of the mulberry buds (T$_{50}$) with the harvesting times and methods in autumn. Cold hardening occurred in the early through the end of September with the peak at the mid-september. During this period, leaf harvest decreased freezing tolerance with remarkable decrease due to picking all the leaves and leaving several leaves at the base of branch. Greater cold hardening was induced by leaving several leaves after topping. 3. Negative correlations were observed between freezing tolerance and the contents of soluble (r =-0.70*) and crude (r= -0.70*) protein. However, positive correlations were shown between freezing tolerance and total carbohydrate contents per crude (r=0.31*) and per soluble (r=0.71*) protein . There were also positive correlations between freezing tolerance and total sugar (r=0.67*) and RNA content (r=0.99**). No relationships of dry matter. fat. total carbohydrate and DNA contents were observed to the freezing tolerance. 4. Such sugars as raffinose. lactose, sucrose, glucose, fructose. arabinose. xylose. ribose (assumed) and rhamnose were detected in winter mulberry branch. Major sugars such as sucrose, glucose, and fructose were supposed to have higher relationship to the freezing tolerance than the other sugars. 5. Late harvesting increased RNA content except in the case of total leaf picking at mid-September. Leaf picking decreased RNA content. Some amount of RNA was, however, maintained by leaving several leaves after topping Leaving upper-middle leaves of a branch showed high RNA content. Leaving young leaves at the top and the overmatured leaves at the base showed low content. A positive correlation (r=0.51*) was noted between RNA content and freezing tolerance in the different harvesting methods.s.
Journal of the Korea Institute of Building Construction
/
v.17
no.6
/
pp.577-585
/
2017
HPC method is developing to improve the constructability and structural performance of the existing PC method. The objective of this study is to develop construction procedures and to analysis of construction period for HPC method. In order to develop construction procedures, the building construction data of the existing half-slab method was analyzed. Analyzing design drawings and specifications of nine construction cases, a prototype of half-slab method, was drawn. Applying the core technology of HPC method to the drawn prototype of half-slab method, a prototype of HPC method, was developed. The differences of both methods were 'installing PC column' and 'placing topping concrete'. To analysis the differences of both methods, seven construction cases were analyzed. According to the analysis for HPC method, cases1 and 2 had columns divided for construction shortened about 16% of a construction period. The schedule of column assembly work was analyzed to be shortened much. That is judged to be because the use of a hollow PC column leads to a decrease in the number of columns. In particular, if HPC method is applied to a building construction site using large columns, it is analyzed to shorten a construction period more than the existing Half-slab method.
A field experiment was conducted to find out the effects of nitrogen and potassium rates on the growing characters, yield and quality of burley tobacco (1988 : Burley 21, 1989: Burley 21 and KB101) during successive two years. The effect of added nitrogen fertilizer on the growth characters at topping stage was different according to growing years. Potassium rate had no effect on the growth characters. The effects of nitrogen and potassium rates on the nitrogen conteut of leaf during growth stage were great, while the effects on the potassium content were not large, relatively. As compared with Burley 21, KB101 showed high yield, and the productivity in nitrogen-reduced condition was high. The yield and quality were increased when nitrogen applied to 22.75kg/l0a, but the yield was not increased and the quality was decreased when nitrogen applied above 22.75kg/l0a. Neither potassium rate nor potassium/nitrogen application ratio had effects on the yield and quality, while the quality was somewhat decreased when potassium/nitrogen ratio was small. When the nitrogen fertilizer being applied above 22.75kg/l0a, there were no advantageous effects on the yield and quality, It is sufficient that the potassium application is about 35.0kg/l0a, and the scheme of reducing of potassium rate may be considerable.
Based on U-shaped composite beam, the new form of AU-composite beam were developed to create economical and efficient components reducing the cost and shortening the length of construction work. Because the U-shaped sections are open and needs to be fixed by topping concrete securely. Therefore, it is required to maintain the U-shaped sections in a structure and to work in the safe condition through construction. It also requires accessories that resist the horizontal shear force for synthesis between the top and bottom of the U-shaped section. To reinforce these shortcomings, a shear connector has been developed with various purposes of steel plate anchors. In this study, the steel plate anchors were directly tested and the shear force was evaluated by the horizontal shear force. The experiment was divided into two types, depending on the applicable deck plates. As a result of the experiment, the continuous type specimens showed greater resistance in both strength and displacement than the ones of stud anchor specimen. In discontinuous type case, due to shear simulations and simple element analysis, the less increase the ratio of width to height and the more shear strength decreased. Thus, the shear strength equation of the stud anchor was modified to suggest the new shear strength based on the testing results.
This paper presents a reinforced concrete composite deck slab system newly developed using a high ductile ECC extrusion panel. In the construction practice, the cracking of reinforced concrete slab often becomes a problem especially in parking garages, underground structures, and buildings. The ECC panel manufactured by extrusion process as a precast product has not only a high-quality in control of cracking but also a merit in applying the construction of concrete slab because the use of ECC panel can realize a formless or half-precast construction with cast-in-place concrete. In the newly developed deck slab system, the ECC extrusion panel is located in the bottom of slab with the thickness of 10 mm, reinforcements are assembled and located on the ECC panel, and finally the topping concrete is placed in the field. In order to evaluate the newly developed slab system, experimental works by four point bending test are conducted to compare with the conventional reinforced concrete slab system. From experiment, the developed deck slab system using a ECC panel gives many improved performances both in control of bending cracking and in load-carrying capacities of slabs.
The present experiments were carried out to find out the proper concentration of CEPA(2-chloroethy-lphosphonic acid) for the purpose of accelerating the leaf maturity and of reducing the nicotine content of tobacco. Varried levels of CEPA were sprayed Yellow Special A right after topping. The effects of each level CEPA treatment on leaf ripening and total alkaloid contents were periodically observed. The results are summarized as follows; 1. The higher the CEPA concentration was, the more the leaf maturity was accelerated. During the period from six to 11 days after treatment, the differences of leaf maturity among levels were prominent. 2. Treatment with CEPA only on the upper surface of the tobacco leaf, accelerated the maturity of that particular part treated, but not apparently the other parts of leaf. 3. The higher the CEPA concentration was, the more the accumulation of the total alkaloid was reduced. The reduction of alkaloid accumulation was evident after acceleration of leaf maturity. 4. Distinctive acceleration of leaf maturity was observed in the fully developed lower leaves, while reduction of alkaloid accumulation in the growing upper leaves. The degree of total alkaloid content reduced in the ripened leaves, however, were similer to all the leaves at different positions. 5. Yields of tobacco leaves were not significantly affected by CEPA treatment. 6. In the present experiments, it may be concluded that CEPA2, 000ppm is the most applicable level for accelerating leaf maturity and decreasing total alkaloid content. In the view point of the practical use, however, the applicable level is assumed to be properly choosed between 500 to 2, 000ppm, depending on the situations. 7. The mechanism of accelerating maturity and reducing alkaloid accumulation of tobacco leaves by CEPA, is further to be explored.
This study was conducted to assess the vibration capacity and the fire resistance capacity of a deck plate slab using an omega steel plate as the void deck plate. First, to evaluate the vibration capacity of the deck plate slab after the insertion of the omega steel plate, three 150mm specimens and three 200mm specimens were made using the slab depth as the main variable. Each specimen consisted of an existing deck plate and two specimens, using the topping depth as the variable according to the slab depth. Second, two real-size specimens were made to evaluate the fire resistance capacity. The results of the test showed that the steel-wire-integrated deck plate slab that was inserted in the omega steel plate did not have a vibration problem due to the void deck plate, because the natural frequency was 12.66-14.09 Hz in the vibration test, and each specimen satisfied the appraisal standards for the load capacity, heat block quality, and chloride inhibition for two hours in the fire resistance test. Consequently, the steel-wire-integrated deck plate slab that was inserted in the omega steel plate can be reduced using the concrete volume and can have higher vibration and fire resistance capacities, similar to the existing deck plate.
Postharvest decay of onion bulbs was examined by inspecting the commercial packages in the market or in storage. Bulb rot incidence was unexpectedly high, and onion bulbs with 1st quality grade were rotten most severely by 51%, followed by 32% for 2nd and 21% for 3rd grades. This indicates that larger bulbs had higher incidences of bulb rots. Major pathogens associated with basal and neck rots were Fusarium oxysporum and Aspergillus sp. or Botrytis allii, respectively, of which basal rot was most prevalent and damaging during storage. Among the epiphytic microorgani는 from onion plants, several Bacillus and Paenibacillus spp. and previously selected Pseudomonas putida and Trichoderma harzianum had inhibitory efficacy against bulb rot pathogens. Among these B. amyloliquefaciens BL-3, Paenibacillus polymyxa BL-4, and P. putida Cha 94 were highly inhibitory to conidial germination of F. oxysporum and B. allii. P. putida Cha 94, B. amyloliquefaciens BL-3, P. polymyxa BL-4, and T. harzianum TM were applied in the rhizoplane of onion at transplanting. Initially antagonist populations decreased rapidly during the first one month. However, among these antagonists, rhizoplane population densities of BL-3, Cha 94, and TM were consistently high thereafter, maintaining about 10$^4$-10$^{5}$ cells or spores per gram of onion root up to harvest time. The other bacterial antagonist BL-4 survived only for two months. TM was the most effective biocontrol agent against basal rot, with the number of rotten bulbs recorded at 4%, while that of the control was 16%. Cha 94 was effective for the first 20 days, but basal rot increased thereafter and had about the same control efficacy as that of BL-3 and BL-4. When the antagonists were applied to the topping areas of onion bulbs at harvest, TM was the most effective in protecting the stored onion bulbs from neck rotting. The second effective antagonist was BL-3. TM and BL-3 completely suppressed the neck rot in another test, suggesting that biocontrol of postharvest decay of onion using these microorganisms either at the time of transplanting or at harvesting may be promising.
본 웹사이트에 게시된 이메일 주소가 전자우편 수집 프로그램이나
그 밖의 기술적 장치를 이용하여 무단으로 수집되는 것을 거부하며,
이를 위반시 정보통신망법에 의해 형사 처벌됨을 유념하시기 바랍니다.
[게시일 2004년 10월 1일]
이용약관
제 1 장 총칙
제 1 조 (목적)
이 이용약관은 KoreaScience 홈페이지(이하 “당 사이트”)에서 제공하는 인터넷 서비스(이하 '서비스')의 가입조건 및 이용에 관한 제반 사항과 기타 필요한 사항을 구체적으로 규정함을 목적으로 합니다.
제 2 조 (용어의 정의)
① "이용자"라 함은 당 사이트에 접속하여 이 약관에 따라 당 사이트가 제공하는 서비스를 받는 회원 및 비회원을
말합니다.
② "회원"이라 함은 서비스를 이용하기 위하여 당 사이트에 개인정보를 제공하여 아이디(ID)와 비밀번호를 부여
받은 자를 말합니다.
③ "회원 아이디(ID)"라 함은 회원의 식별 및 서비스 이용을 위하여 자신이 선정한 문자 및 숫자의 조합을
말합니다.
④ "비밀번호(패스워드)"라 함은 회원이 자신의 비밀보호를 위하여 선정한 문자 및 숫자의 조합을 말합니다.
제 3 조 (이용약관의 효력 및 변경)
① 이 약관은 당 사이트에 게시하거나 기타의 방법으로 회원에게 공지함으로써 효력이 발생합니다.
② 당 사이트는 이 약관을 개정할 경우에 적용일자 및 개정사유를 명시하여 현행 약관과 함께 당 사이트의
초기화면에 그 적용일자 7일 이전부터 적용일자 전일까지 공지합니다. 다만, 회원에게 불리하게 약관내용을
변경하는 경우에는 최소한 30일 이상의 사전 유예기간을 두고 공지합니다. 이 경우 당 사이트는 개정 전
내용과 개정 후 내용을 명확하게 비교하여 이용자가 알기 쉽도록 표시합니다.
제 4 조(약관 외 준칙)
① 이 약관은 당 사이트가 제공하는 서비스에 관한 이용안내와 함께 적용됩니다.
② 이 약관에 명시되지 아니한 사항은 관계법령의 규정이 적용됩니다.
제 2 장 이용계약의 체결
제 5 조 (이용계약의 성립 등)
① 이용계약은 이용고객이 당 사이트가 정한 약관에 「동의합니다」를 선택하고, 당 사이트가 정한
온라인신청양식을 작성하여 서비스 이용을 신청한 후, 당 사이트가 이를 승낙함으로써 성립합니다.
② 제1항의 승낙은 당 사이트가 제공하는 과학기술정보검색, 맞춤정보, 서지정보 등 다른 서비스의 이용승낙을
포함합니다.
제 6 조 (회원가입)
서비스를 이용하고자 하는 고객은 당 사이트에서 정한 회원가입양식에 개인정보를 기재하여 가입을 하여야 합니다.
제 7 조 (개인정보의 보호 및 사용)
당 사이트는 관계법령이 정하는 바에 따라 회원 등록정보를 포함한 회원의 개인정보를 보호하기 위해 노력합니다. 회원 개인정보의 보호 및 사용에 대해서는 관련법령 및 당 사이트의 개인정보 보호정책이 적용됩니다.
제 8 조 (이용 신청의 승낙과 제한)
① 당 사이트는 제6조의 규정에 의한 이용신청고객에 대하여 서비스 이용을 승낙합니다.
② 당 사이트는 아래사항에 해당하는 경우에 대해서 승낙하지 아니 합니다.
- 이용계약 신청서의 내용을 허위로 기재한 경우
- 기타 규정한 제반사항을 위반하며 신청하는 경우
제 9 조 (회원 ID 부여 및 변경 등)
① 당 사이트는 이용고객에 대하여 약관에 정하는 바에 따라 자신이 선정한 회원 ID를 부여합니다.
② 회원 ID는 원칙적으로 변경이 불가하며 부득이한 사유로 인하여 변경 하고자 하는 경우에는 해당 ID를
해지하고 재가입해야 합니다.
③ 기타 회원 개인정보 관리 및 변경 등에 관한 사항은 서비스별 안내에 정하는 바에 의합니다.
제 3 장 계약 당사자의 의무
제 10 조 (KISTI의 의무)
① 당 사이트는 이용고객이 희망한 서비스 제공 개시일에 특별한 사정이 없는 한 서비스를 이용할 수 있도록
하여야 합니다.
② 당 사이트는 개인정보 보호를 위해 보안시스템을 구축하며 개인정보 보호정책을 공시하고 준수합니다.
③ 당 사이트는 회원으로부터 제기되는 의견이나 불만이 정당하다고 객관적으로 인정될 경우에는 적절한 절차를
거쳐 즉시 처리하여야 합니다. 다만, 즉시 처리가 곤란한 경우는 회원에게 그 사유와 처리일정을 통보하여야
합니다.
제 11 조 (회원의 의무)
① 이용자는 회원가입 신청 또는 회원정보 변경 시 실명으로 모든 사항을 사실에 근거하여 작성하여야 하며,
허위 또는 타인의 정보를 등록할 경우 일체의 권리를 주장할 수 없습니다.
② 당 사이트가 관계법령 및 개인정보 보호정책에 의거하여 그 책임을 지는 경우를 제외하고 회원에게 부여된
ID의 비밀번호 관리소홀, 부정사용에 의하여 발생하는 모든 결과에 대한 책임은 회원에게 있습니다.
③ 회원은 당 사이트 및 제 3자의 지적 재산권을 침해해서는 안 됩니다.
제 4 장 서비스의 이용
제 12 조 (서비스 이용 시간)
① 서비스 이용은 당 사이트의 업무상 또는 기술상 특별한 지장이 없는 한 연중무휴, 1일 24시간 운영을
원칙으로 합니다. 단, 당 사이트는 시스템 정기점검, 증설 및 교체를 위해 당 사이트가 정한 날이나 시간에
서비스를 일시 중단할 수 있으며, 예정되어 있는 작업으로 인한 서비스 일시중단은 당 사이트 홈페이지를
통해 사전에 공지합니다.
② 당 사이트는 서비스를 특정범위로 분할하여 각 범위별로 이용가능시간을 별도로 지정할 수 있습니다. 다만
이 경우 그 내용을 공지합니다.
제 13 조 (홈페이지 저작권)
① NDSL에서 제공하는 모든 저작물의 저작권은 원저작자에게 있으며, KISTI는 복제/배포/전송권을 확보하고
있습니다.
② NDSL에서 제공하는 콘텐츠를 상업적 및 기타 영리목적으로 복제/배포/전송할 경우 사전에 KISTI의 허락을
받아야 합니다.
③ NDSL에서 제공하는 콘텐츠를 보도, 비평, 교육, 연구 등을 위하여 정당한 범위 안에서 공정한 관행에
합치되게 인용할 수 있습니다.
④ NDSL에서 제공하는 콘텐츠를 무단 복제, 전송, 배포 기타 저작권법에 위반되는 방법으로 이용할 경우
저작권법 제136조에 따라 5년 이하의 징역 또는 5천만 원 이하의 벌금에 처해질 수 있습니다.
제 14 조 (유료서비스)
① 당 사이트 및 협력기관이 정한 유료서비스(원문복사 등)는 별도로 정해진 바에 따르며, 변경사항은 시행 전에
당 사이트 홈페이지를 통하여 회원에게 공지합니다.
② 유료서비스를 이용하려는 회원은 정해진 요금체계에 따라 요금을 납부해야 합니다.
제 5 장 계약 해지 및 이용 제한
제 15 조 (계약 해지)
회원이 이용계약을 해지하고자 하는 때에는 [가입해지] 메뉴를 이용해 직접 해지해야 합니다.
제 16 조 (서비스 이용제한)
① 당 사이트는 회원이 서비스 이용내용에 있어서 본 약관 제 11조 내용을 위반하거나, 다음 각 호에 해당하는
경우 서비스 이용을 제한할 수 있습니다.
- 2년 이상 서비스를 이용한 적이 없는 경우
- 기타 정상적인 서비스 운영에 방해가 될 경우
② 상기 이용제한 규정에 따라 서비스를 이용하는 회원에게 서비스 이용에 대하여 별도 공지 없이 서비스 이용의
일시정지, 이용계약 해지 할 수 있습니다.
제 17 조 (전자우편주소 수집 금지)
회원은 전자우편주소 추출기 등을 이용하여 전자우편주소를 수집 또는 제3자에게 제공할 수 없습니다.
제 6 장 손해배상 및 기타사항
제 18 조 (손해배상)
당 사이트는 무료로 제공되는 서비스와 관련하여 회원에게 어떠한 손해가 발생하더라도 당 사이트가 고의 또는 과실로 인한 손해발생을 제외하고는 이에 대하여 책임을 부담하지 아니합니다.
제 19 조 (관할 법원)
서비스 이용으로 발생한 분쟁에 대해 소송이 제기되는 경우 민사 소송법상의 관할 법원에 제기합니다.
[부 칙]
1. (시행일) 이 약관은 2016년 9월 5일부터 적용되며, 종전 약관은 본 약관으로 대체되며, 개정된 약관의 적용일 이전 가입자도 개정된 약관의 적용을 받습니다.