• Journal of Forest and Environmental Science
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• 제39권1호
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• pp.27-39
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• 2023

Twenty-five Eucalyptus clones (14 E. camaldulensis - EC and 11 interspecific eucalypt hybrid clones - EH) grown in three contrasting sites were evaluated for the growth and few wood traits at 4 years of age. The stability, genotype-site interaction and suitability of these clones for pulp and solid wood industry sectors were studied. Growth of eucalypt clones was significantly higher at site 1 with higher rainfall, but wood density did not differ significantly from lower rainfall sites. Kraft pulp yield (KPY) decreased from sites 1 to 3 based on moisture availability, but not between two groups of clones. Volumetric shrinkage (VS) was significantly higher in EC clones at site 3 with lowest rainfall, but there was no specific trend at other two sites with maximum (site 1) and intermediate (site 2) rainfall. The mechanical traits modulus of rupture (MOR) and modulus of elasticity (MOE) were at par in sites 1 and 2, but significantly lower at the driest site 3. The growth rate had a significant positive correlation with KPY, MOR and MOE and a negative correlation with VS, but no significant impact on wood density in both groups of clones. Genotype×environment interaction (G×E) was evident in most traits due to the difference in response of clones to moisture availability. Since wood density was negatively correlated to KPY, it has to be kept at an optimum level for the profitability of pulp industry. There was no significant difference between EC and EH clones for most traits except VS at site 3. Stability of clones varied across sites in different traits, and hence clones may be selected for deployment at each site by screening for growth, followed by wood density, considering the relationship of growth and density with other traits required by pulp and solid wood industry sectors.

• Journal of the Korean Wood Science and Technology
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• 제43권4호
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• pp.446-455
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• 2015

국내외 기계등급제재목(구조재 및 층재)의 등급기준 및 설계강도 산출방법을 비교 분석하고 국내 제재산업 실정을 고려한 평균 탄성계수(modulus of elasticity, 이하 MOE) 기준방법 적용을 제안하였다. 먼저 올바른 기계등급제재목 기준 정착을 위해 기계등급구조재와 기계등급층재의 공통점과 차이점을 설명하였다. 최소 고정 MOE 기준 등급을 사용하는 국내 기준은 등급구분에는 편리하나 휨강도(modulus of rupture, 이하 MOR) 예측과 자원이용도 측면에서는 효율성이 낮은 것으로 파악되었다. 해외에서 사용되는 평균 MOE 기준 방법은 초기 컴퓨터 기반 작동을 요구하나 MOR-MOE 직선회귀에 근거한 합리적인 MOR 예측과 품질관리 측면에서 효율성이 높은 것으로 분석되었다. 무엇보다도 현 국내 기계등급구조재 등급체계는 수종별 강도 특성을 반영하지 못하고 있다는 것이 가장 큰 문제점으로 분석되었으며 이러한 결과를 기반으로 MOR-MOE 직선회귀분석에 근거한 기계등급제재목 등급기준 및 기준설계값 산출방법 적용을 제안하였다. 이를 통하여 궁극적으로 부가가치가 높은 국산 기계등급구조재 생산 활성화를 이루고, 기계 등급구조재의 층재 전용 가능에 따른 구조용 집성재 가격경쟁력 제고 효과를 얻을 수 있다고 사료되었다.

• 농업생명과학연구
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• 제44권5호
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• pp.1-8
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• 2010

이 연구에서는 녹차를 이용한 친환경 복합보드를 건축내장재로의 활용을 위하여, 녹차의 다양한 기능성과 목재섬유의 우수한 강도특성을 살려 녹차-목재섬유 복합보드를 제작하였고, 녹차-목재섬유 복합보드의 정적 휨강도성능에 미치는 녹차와 목재섬유 배합비율 및 접착제의 영향을 조사하였다. 녹차-목재섬유복합보드의 휨 강도성능은 녹차의 배합에 따라 대조보드 (control 보드) 보드의 그것보다 감소하였는데, 그 감소비율은 전반적으로 녹차배합비율이 증가할수록 커지는 경향을 나타내었다. 또한, 보드제조에 사용된 수지의 종류에 따라 강도성능의 차이가 나타났는데, 포름알데히드 방산량이 많은 $E_1$급 요소수지가 $E_0$급 요소수지보다 휨 탄성계수에서는 1.08~1.53배 그리고 휨 강도는 1.19~1.82배의 더 높은 값을 나타내었으며, 녹차의 배합비율이 커질수록 양자의 차이는 커지는 것이 확인되었다. 휨 강도는 $E_1$급 요소수지의 경우, 시판용 중밀도섬유판 (medium density fiberboard, MDF)의 0.94~1.03배의 값을 나타내어 시판용 중밀도섬유판과 거의 차이가 없었고, 녹차와 목재섬유를 복합한 우수한 친환경 기능성복합보드제조가 가능한 것이 밝혀졌다.

• Clinical and Experimental Pediatrics
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• 제48권3호
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• pp.333-336
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• 2005

저자들은 1년간의 오심과 상복부 통증으로 인해 만성위염으로 오진되었던 기관지성 낭종 1례를 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

• 한국분말재료학회지
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• 제15권5호
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• pp.359-364
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• 2008

To satisfy the demand of higher cutting performance, mechanical properties with tungsten carbide (WC-Co) tool materials were investigated. Hardness and transverse rupture strength with WC grain size, Co content and density were measured. Compared to H, K, and S manufacture maker as tungsten carbide (WC-Co) tool materials were used for high-speed machining of end-milling operation. The three tungsten carbide (WC-Co) tool materials were evaluated by cutting of STD 11 cold-worked die steel (HRC25) under high-speed cutting condition. Also, tool life was obtained from measuring flank wear by CCD wear measuring system. Tool dynamometer was used to measure cutting force. The cutting force and tool wear are discussed along with tool material characteristics. Consequently, the end-mill of K, H manufacture maker showed higher wear-resistance due to its higher hardness, while the S maker endmill tool showed better performance for high metal removal.

• 가족자원경영과 정책
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• 제16권2호
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• pp.145-163
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• 2012

The purpose of this study is to understand the process of "standing alone" in divorced single fathers on the basis of qualitative data collected through in-depth interviews with 10 divorced single fathers. Data were analyzed on the basis of grounded theory analysis in open coding, and 154 concepts, 39 sub-categories, and 14 categories were derived. According to the results of this study, the process phenomenon of divorced single fathers' standing alone was "the restraint and chaos of pain". This study could identify the consecutive process of four identified stages: marriage life's rupture, pain and chaos, deliberation and decision, and role adaption. In selective coding, the core category was "to pass through the restraint of pain and embrace children and stand alone". There were three types of standing alone: maintaining barely, enduring hopefully, and living initiatively. This study showed the necessity of social support and the basic data by type analysis through the process of standing alone. This study provided substantive knowledge generated through the voices of the persons concerned.

• Journal of Chest Surgery
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• 제50권5호
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• pp.403-406
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• 2017

Tracheobronchial rupture due to blunt chest trauma is a rare but life-threatening injury in the pediatric population. Computed tomography (CT) is not always reliable in the management of these patients. An additional concern is that ventilation may be disrupted during surgical repair of these injuries. This report presents the case of a 4 -year-old boy with an injury to the lower trachea and carina due to blunt force trauma that was missed on the initial CT scan. During surgery, he was administered venoarterial extracorporeal membrane oxygenation (ECMO). Although ECMO is not generally used in children, this case demonstrated that the short-term use of ECMO during pediatric surgery is safe and can prevent intraoperative desaturation.

• Journal of Chest Surgery
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• 제49권6호
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• pp.478-480
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• 2016

Spontaneous perforation of the esophagus after forceful vomiting is known as Boerhaave syndrome, a rare and life-threatening condition associated with a high rate of mortality. The management of Boerhaave syndrome is challenging, especially when diagnosed late. Herein, we report the successful management of late-diagnosed Boerhaave syndrome with T-tube drainage in a 55-year-old man. The patient was transferred to our institution 8 days after the onset of symptoms, successfully managed by placing a T-tube, and was discharged on postoperative day 46 without complications.

• Journal of Chest Surgery
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• 제50권3호
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• pp.137-143
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• 2017

Acute complicated type B aortic dissection (TBAD) is a potentially catastrophic, life-threatening condition. If left untreated, there is a high risk of aortic rupture, irreversible organ or limb damage, or death. Several risk factors have been associated with acute complicated TBAD, including age and refractory hypertension. In the acute phase, even uncomplicated patients are more prone to develop complications if hypertension and pain are left medically untreated. Innovations in stent graft technologies have incrementally improved outcomes since their first use for this condition in 1999, though improvement is needed in mitigating periprocedural complications, adverse events, and mortality. In the past decade, endovascular repair has become the preferred treatment because of its superior outcomes to open repair and medical therapy. The Valiant Captivia Thoracic Stent Graft System is a third-generation endovascular stent graft with advancements in minimally invasive delivery, conformability to the anatomy, and the minimization of adverse sequelae. Herein, this stent graft is briefly reviewed and its 3-year outcomes are presented. Freedom from all-cause and dissection-related mortality was 79.1% and 90.0%, respectiv ely. The Valiant Captiv ia Stent Graft represents a safe, effective intervention for acute complicated TBAD. Continued surveillance is needed to verify its longer-term durability.

• Clinical and Experimental Pediatrics
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• 제48권6호
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• pp.660-664
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• 2005

저자들은 신생아 시기에 심부전 증세를 보인 간내 혈관내피종 환아에서 내과적 치료와 간동맥 색전술 후 호전을 보이지 않아 간좌엽 절제술을 시행하여 치료한 1례를 경험하였기에 보고하는 바이다.