• 제목/요약/키워드: J hook

검색결과 42건 처리시간 0.021초

향나무 잎의 추출성분 (Extractive of Juniper Needle)

  • 배영수;;김진규
    • 임산에너지
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    • 24권2호
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    • pp.24-30
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    • 2005
  • 향나무 잎을 채취하여 분쇄한 후 MeOH로 추출하고 분획한 다음 EtOAc 및 수용성 화합물을 칼럼크로마토그래피법을 사용하여 4개의 화합물 (+)-catechin (1), (-)-epicatechin (2), myricitrin (3) 및 hinokiflavone (4)을 단리하였다. 단리 화합물은 NMR 및 질량분석기를 사용하여 그 구조를 구명하였으며 DPPH radical 소거법을 이용하여 항산화 활성 검정을 시행하였다. 4가지 화합물 모두 우수한 활성을 보였으며 화합물 1, 2 및 3은 대조구로 사용한 ${\alpha}-tocopherol$, BHT 및 curcumin 보다 우수하였으나 화합물 4는 대조구보다 약간 낮은 활성을 나타내었다.

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주행 안정성을 고려한 최악 상황 시나리오 도출 및 적용 (Worst Case Scenario Generation on Vehicle Dynamic Stability and Its Application)

  • 정대이;정도현;문기현;정창현;노기한;최형진
    • 한국자동차공학회논문집
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    • 제16권6호
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    • pp.1-9
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    • 2008
  • The current test methods are insufficient to evaluate and ensure the safety and reliability of vehicle system for all possible dynamic situation including the worst case such as rollover, spin-out and so on. Although the known NHTSA J-turn and Fish-hook steering maneuvers are applied for the vehicle performance assessment, they aren't enough to estimate other possible worst case scenarios. Therefore, it is crucial for us to verify the various worst cases including the existing severe steering maneuvers. This paper includes the procedure to search for other useful worst case based upon the existing worst case scenarios mentioned above and its application in simulation basis. The only human steering angle is selected as a design parameter here and optimized to maximize the index function to be expressed in terms of either roll angle or yaw rate. The obtained scenarios were enough to generate the worst case to meet NHTSA worst case definition (ex.2-inch wheel lift). Additionally, as an application, the worst case steering maneuver is acquired for the vehicle to operate with a simple ESP system. It has been concluded that the new procedure in this paper is adequate to create other feasible worst case scenarios for a vehicle system both with an intelligent safety control system and without it.

승용차용 능동제어식 현가시스템의 개발(2); 실차 성능실험 및 결과 (Development of an Active Suspension System for Passenger Cars( II ) ; Prototype Car Test Result)

  • 황요하;홍예선;이종민;배준영
    • 한국자동차공학회논문집
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    • 제2권2호
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    • pp.83-94
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    • 1994
  • Performance test result on prototype car equipped with low-band type active suspension system is reported. Control theory is explained first. Simulation for feasibility and parameter tuning, control module test using hydraulic exciter and test run, and performance evaluation of the test car on test track are reported successively. Emphasis was put on modification of control theory which caused many unexpected problems in actual implementation.

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승용차용 능동제어식 현가시스템의 개발(1) : 실험차량의 구성 (Development of an Active Suspension System for Passenger Cars( I ) : Construction of Prototype Car)

  • 홍예선;황요하;김동윤;김영범;심재진
    • 한국자동차공학회논문집
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    • 제2권2호
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    • pp.73-82
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    • 1994
  • Low-band type active suspension system is implemented on a passenger car. Level. roll, pitch and bouncing motion of body are controlled by a digital controller. Sky-hook damper is applied to control bouncing motion. This paper describes overall construction of the system, design of hydraulic system, sensor system, controller, and control scheme. Performance of prototype car has been evaluated on a test track and reported in the second paper.

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농촌(農村)에 있어서의 구충감염현황(鉤虫感染現況) (On the status of hookworm infection in rural areas in korea)

  • 임한종;김정준;이준상;주경환;송오달
    • 농촌의학ㆍ지역보건
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    • 제4권1호
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    • pp.62-70
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    • 1979
  • In order to evaluate the present status of hook-worm infection in the rural areas in Korea, stool examinations were undertaken in several selected rural villages in each year of 1970 and 1977. The methods employed were cellophane thick smear technique and brine floatation technique in 3,454 specimens collected from 7 different rural villages for the prevalence rate of hookworm infection and Stoll's dilution egg counting technique for the intensity of hookworm infection. The incidences of Ancylostoma duodenale and Necator americanus infections were determind by polyethylene tube coproculture and by the evacuated adult worms after treatment with anthelmintics to the patients who were infected by hookworms. The results are as follows : 1) In 1970, 323(18.6%) out of 1,737 specimens collected from 4 different rural areas were positive for hook worm infection and the ranges of prevalence rates in those suveyed areas were shown as 6.9 to 38.2 per cent. On the other hand, 144(8.2%) out of 1,717 specimens collected from 3 different rural areas in 1977 were shown as positive for hookworm infection and 7.5 to 10.6 per cent of prvalence rates were shown in the surveyed areas. 2) In the age group under 10 years, there was no infection of hookworm in the studied areas in 1977, however in 1970 the prevalence of the hookworm infection was shown as very low in the age group of 5~9. On the whole, the hookworm prevalence steadily increased from the age of 15 in the studied areas in 1970, however in 1977 the prevalence increased from the age of 20 to the older age groups. 3) There was not observed much differences in the intensity of hookworm infection among the studied areas in 1970 and 1977. The mean EPG in each studied areas were shown under 1,000 EPG and mean numbers of evacuated worms per infected persons were counted as 9.4 to 15. 1. 4) Both A.duodenale and N.americanus have been found in all studied areas but the incidences and st-ate of distribution of two species of hookworn were shown as different in each localities.

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Behaviors of novel sandwich composite beams with normal weight concrete

  • Yan, Jia-Bao;Dong, Xin;Wang, Tao
    • Steel and Composite Structures
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    • 제38권5호
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    • pp.599-615
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    • 2021
  • The ultimate strength behaviour of sandwich composite beams with J-hooks and normal weight concrete (SCSSBJNs) are studied through two-point loading tests on ten full-scale SCSSBJNs. The test results show that the SCSSBJN with different parameters under two-point loads exhibits three types of failure modes, i.e., flexure, shear, and combined shear and flexure mode. SCSSBJN failed in different failure modes exhibits different load-deflection behaviours, and the main difference of these three types of behaviours exist in their last working stages. The influences of thickness of steel faceplate, shear span ratio, concrete core strength, and spacing of J-hooks on structural behaviours of SCSSBJN are discussed and analysed. These test results show that the failure mode of SCSSBJN was sensitive to the thickness of steel faceplate, shear span ratio, and concrete core strength. Theoretical models are developed to estimate the cracking, yielding, and ultimate bending resistance of SCSSBJN as well as its transverse cross-sectional shear resistance. The validations of predictions by these theoretical models proved that they are capable of estimating strengths of novel SCSSBJNs.

INFINITE FAMILIES OF CONGRUENCES MODULO 2 FOR 2-CORE AND 13-CORE PARTITIONS

  • Ankita Jindal;Nabin Kumar Meher
    • 대한수학회지
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    • 제60권5호
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    • pp.1073-1085
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    • 2023
  • A partition of n is called a t-core partition if none of its hook number is divisible by t. In 2019, Hirschhorn and Sellers [5] obtained a parity result for 3-core partition function a3(n). Motivated by this result, both the authors [8] recently proved that for a non-negative integer α, a3αm(n) is almost always divisible by an arbitrary power of 2 and 3 and at(n) is almost always divisible by an arbitrary power of pji, where j is a fixed positive integer and t = pa11pa22···pamm with primes pi ≥ 5. In this article, by using Hecke eigenform theory, we obtain infinite families of congruences and multiplicative identities for a2(n) and a13(n) modulo 2 which generalizes some results of Das [2].

동부태평양 한국의 다랑어 연승어업에서 상어류 체중대비 지느러미 중량 비율 추정 (Estimation of the Ratio of Fin Weight to Body Weight of Sharks for the Korean Tuna Longline Fishery in the Eastern Pacific Ocean)

  • 안두해;권유정;문대연;황선재;김순송
    • 한국수산과학회지
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    • 제42권2호
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    • pp.157-164
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    • 2009
  • The National Fisheries Research and Development Institute (NFRDI) conducted a circle hook experiment to compare the catch rates of target and bycatch species between J hook and circle hooks in the tuna longline fishery of the Eastern Pacific Ocean, which is located between $9^{\circ}13'S-1^{\circ}36'N$ and $126^{\circ}00'-138^{\circ}21'W$. Sampling was conducted from September 20 to October 23, in 2006. In this survey, we collected shark data to obtain the ratio of fin weight to body weight of sharks. Overall, 413 sharks belonging to 9 species were caught on 62,464 hooks. The total weight of the sharks caught was 11,093 kg. The ratio of wet fin weight to body round weight of sharks by species ranged from 3.7% to 7.7%, while the mean was 5.4%. The total ratio of wet fin weight to the dry fin weight of sharks ranged 0.38 to 0.70 and the mean value was 0.53. The ratio of dry fin weight to the body round weight of the sharks was estimated to be 2.86%.

Genetic Variability Based on Randomly Amplified Polymorphic DNA in Kacip Fatimah (Labisia pumila Benth & Hook f) collected from Melaka and Negeri Sembilan States of Malaysia

  • Bhore, Subhash J.;Nurul, A.H.;Shah, Farida H.
    • Journal of Forest and Environmental Science
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    • 제25권2호
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    • pp.93-100
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    • 2009
  • In Malaysia, Labisia pumila Benth & Hook f, popularly known as 'Kacip Fatimah' has been used traditionally to treat various elements of the woman's health in Malay community. The objective of this study was to develop randomly amplified polymorphic DNA (RAPD) based DNA markers for the identification of L. pumila and to distinguish its three varieties from each other. Total DNA from nine accessions of L. pumila was extracted by CTAB method and polymerase chain reactions (PCR) were carried out to amplify the segments of DNA using different primers to develop DNA barcode using RAPD technique. To find out variety-specific DNA marker/s, twenty different 10-mer primer sequences with annealing temperature from 36-$40^{\circ}C$ were evaluated in triplicate. Out of 20 random primers, two primers (OPA-1 and OPA-2/A10) were selected which produced reliable RAPD band patterns. To have DNA based handle, two RAPD amplification products were cloned and sequenced to determine the identity of the DNA. RAPD analysis using two random primers generated 72 discrete bands ranging in size 200 bp-3,000 bp. Fifty nine of these were polymorphic loci (82%) and thirteen were non-polymorphic loci (18%). A total of 32 bands polymorphic loci (72%) were amplified with primer OPA-1 and analyzed by cluster analysis and UPGMA (Unweighted Pair Group Method with Arithmetic) to present a dendogram depicting the degree of genetic relationship among nine accessions of L. pumila. Our results shows the reasonable genetic diversity among the L. pumila varieties and within varieties; and two RAPD marker sequences obtained could be used to identify L. pumila at species level.

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In vitro regeneration of Lycaste aromatica (Graham ex Hook) Lindl. (Orchidaceae) from pseudobulb sections

  • Mata-Rosas, Martin;Baltazar-Garcia, Rosario J.;Moon, Pamela;Hietz, Peter;Luna-Monterrojo, Victor E.
    • Plant Biotechnology Reports
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    • 제4권2호
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    • pp.157-163
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    • 2010
  • A protocol for in vitro propagation from pseudobulb sections of Lycaste armomatica (Graham ex Hook) Lindl., an ornamental and fragrant orchid, was developed. The effect of four cytokinins: kinetin (K), metatopolin (mT), $N^6$-benzyladenine (BA), and thidiazuron (TDZ), in equimolar concentrations, was investigated. Shoot formation from apical and basal pseudobulb sections was obtained in all treatments. A few medial sections cultured in media supplemented with BA formed protocorm-like bodies. Shoot formation was greater from the basal section than the apical, and mainly occurred in explants cultured in media containing TDZ. The highest average numbers of shoots per explant were achieved from basal sections cultured in media supplemented with TDZ at 4.4, 8.87 and 2.2 ${\mu}M$, forming on average 9.9, 8.6 and 7.3 shoots per explant, respectively. Since the medial pseudobulb section was the worst explant for propagation of L. aromatica, we recommend that pseudobulbs be divided into two sections; the basal half should be cultured in MS medium supplemented with TDZ at 4.4 ${\mu}M$ and the apical half with TDZ at 2.2 ${\mu}M$. Subculturing individual shoots in MS medium without plant growth regulators allows further development and rooting. A survival rate of more than 90% under greenhouse conditions was achieved. This research represents a direct contribution to the conservation and sustainable use of this valuable natural resource.