Refiner 에 대한 낙엽송의 Arabinogalactan 추출 및 MgO 에 대한 정제

백기현 한국목재공학회 1987 목재공학 Vol.15 No.4

To extract arabinogalactan from larch (Larix leptolepis), chips immersed with water(20-90℃) for 1 hr. were defiberized by refiner. The liquors were recovered and purified to pure arabinogalactan by ion exchange resin(IRC-50 a. IR-45) or MgO. Additionally the optimal condition in purification with MgO was also investigated. 1. The amounts of solids(crude sugars) and pure arabinogaletan in solids are 8.6-11.3% and 7.3-8.5%(raw material=100), respectively. 2. Phenolic materials in crude sugars are removed up to 96-89% by ion exchange resin and 94-88%, by MgO, while recovery yields of pure arabinogalactan are 81-75% on purification with ion exchange resin and 91-87% on purification with MgO. 3. The optimal conditions of purification with MgO are the addition of 35㎎ Mg0/0.5g of crude sugars, 45 minutes at 70℃, or 25 ㎎ MgO, 30 minutes at 85℃.

Romosozumab in Postmenopausal Korean Women with Osteoporosis: A Randomized, Double-Blind, Placebo-Controlled Efficacy and Safety Study

백기현,정윤석,고정민,김인주,김경민,민용기,박기덕,Rajani Dinavahi,Judy Maddox,Wenjing Yang,김수아,이상진,조형진,임승길 대한내분비학회 2021 Endocrinology and metabolism Vol.36 No.1

Background: This phase 3 study evaluated the efficacy and safety of 6-month treatment with romosozumab in Korean postmenopausal women with osteoporosis. Methods: Sixty-seven postmenopausal women with osteoporosis (bone mineral density [BMD] T-scores ≤–2.5 at the lumbar spine, total hip, or femoral neck) were randomized (1:1) to receive monthly subcutaneous injections of romosozumab (210 mg; n=34) or placebo (n=33) for 6 months. Results: At month 6, the difference in the least square (LS) mean percent change from baseline in lumbar spine BMD (primary efficacy endpoint) between the romosozumab (9.5%) and placebo (–0.1%) groups was significant (9.6%; 95% confidence interval, 7.6 to 11.5; P<0.001). The difference in the LS mean percent change from baseline was also significant for total hip and femoral neck BMD (secondary efficacy endpoints). After treatment with romosozumab, the percent change from baseline in procollagen type 1 Nterminal propeptide transiently increased at months 1 and 3, while that in C-terminal telopeptide of type 1 collagen showed a sustained decrease. No events of cancer, hypocalcemia, injection site reaction, positively adjudicated atypical femoral fracture or osteonecrosis of the jaw, or positively adjudicated serious cardiovascular adverse events were observed. At month 9, 17.6% and 2.9% ofpatients in the romosozumab group developed binding and neutralizing antibodies, respectively. Conclusion: Treatment with romosozumab for 6 months was well tolerated and significantly increased lumbar spine, total hip, and femoral neck BMD compared with placebo in Korean postmenopausal women with osteoporosis (ClinicalTrials.gov identifier NCT02791516).

접착제로서 크라프트 리그닌 폐액의 이용

백기현,박광만 한국목재공학회 1987 목재공학 Vol.15 No.1

A kraft black liquor obtained from gulping of pine (Pines densiflora Sieb et Zucc) was used for producing three kinds of adhesive sects as black liquor-phenol formaldehyde resin, methyloeated kraft lignin-phenol formaldehyde resin, and lignin sake-phenol resin. In case of producing black liquor-phenol formaldehyde resin, about 60 percent of the phenolic resin could be replaced by black liquor. Also tile optimal press condition appeared to be 160℃ for 7 min. (15.77Kg/㎠ in dry test, 8.54Kg/㎠ in 4 hr. boil test). Phenol could be substituted up to 80-90 percent by methylolated kraft lignin. The suitable conditions of factors affecting bond quality were pH to 2.6, methanol as solvent and 0.2ml formaldehyde per 1g of the adhesives, respectively. The optimal press condition was 150℃ for 4 min. (18.54Kg/㎠ in dry test, 10.08Kg/㎠ in 4 hr. boil test). In preparing lignin cake-phenol resin, a suitable mixing ratio of phenol to powered kraft lignin was one to one by weight. The optimal press condition was 150℃ for 4 min. (18.46Kg/㎠ in dry test, 12.31Kg/㎠ in 4 hr. hail test).

낙엽송 심재의 CCA 와 CCFZ 처리특성 및 자상처리(刺傷處理)에 의한 CCA 처리도 개선

백기현,김규혁,강승모 한국목재공학회 1995 목재공학 Vol.23 No.4

The treatability of Japanese larch heartwood was assessed by pressure treatment of non-incised dimension material with CCA or CCFZ. The effectiveness of incising(conventional, high density, and needle incising) for improving CCA treatability on refractory Japanese larch heartwood was also investigated. Preservative retention and penetration were somewhat greater with CCFZ treatment. although thaw was generally poor in both preservatives. The retention gradients for both CCA and CCFZ-treated stock were essentially the same shape. Treatment of non-incised material with CCA achieved the recommended treatability for using treated wood at the regions of hazard class H2 in the Japanese Agricultural Standards. However, Japanese larch heartwood would require incising as a pretreatment for enhancing treatability, if CCA-treated larch is intended to be used at the regions of hazard class H3 and H4. As expected, incising resulted in a considerable improvement of preservative treatablity, particularly penetration. and the effect of incising on the improvement of treatability was excellent at the sequence of needle incising, high density incising, and conventional incising. Among incising techniques investigated in this study, high density and needle incisinf; enhanced CCA treatability beyond the point where it did meet a minimum requirements specified by the Japanese Agricultural Standards for using CCA-treated Japanese larch at the regions of hazard class H3 and even H4.

여러 가지 보류시스템에서 탄산칼슘의 보류와 종이의 기계적 , 광학적 특성의 비교

백기현,안병준,손상돈 ( Ki Hyon Paik,Byoung Jun Ahn,Sang Don Shon ) 한국공업화학회 1996 공업화학 Vol.7 No.2

본 실험에서는 보류향상제의 첨가량과 중질 탄산칼슘 첨가량에 따른 탄산칼슘 보류량(회분함량)을 조사하였으며, 동일 회분량에서 종이의 기계적·광학적 특성을 비교하였다. 각 보류시스템 모두 보류향상제 첨가량을 증가시키면 중질 탄산칼슘(입자평균직경 3.2㎛) 보류, 즉 종이의 회분량은 증가한다. 이 경우 보류향상제와 중질 탄산칼슘 첨가량을 조절하여 이미 예정된 회분량이 함유된 종이를 초지할 수 있다. 종이의 인장지수, 파열지수, 인열지수 및 내부결합강도는 종이의 회분량이 증가됨에 따라 직선적으로 감소한다. 특히 동일 회분량에서 비교하면, 콤포질 시스템에 의한 종이에서 제반 강도가 높고, 듀알 폴리머 시스템에서는 강도가 낮다. 불투명도는 회분량 증가에 따라 함께 증가하며, 하이드로콜 시스템에서 가장 높고 역시 듀알 폴리머에서 가장 낮다. 동일 불투명도에서 종이의 강도는 콤포질, 하이드로콜, 듀알 폴리머 시스템 순으로 감소한다. 그러나 보류향상제의 우열을 판단하기 위해서는 충전제의 보류량과 종이의 강도 이외에도 적정 생산조건 및 적정 공정조건과 같은 여러 가지 다른 요인들도 고려되어야 한다. In this paper, we investigated the retention amounts(ash contents) according to the addition amounts of retention aid and calcium carbonate and compared the mechanical and optical properties of sheets under the same ash content. As the addition amounts of retention aid increase, the retention of calcium carbonate, that is, ash contents of sheets increase in all retention system. In this case, the sheets included ash content as already expected is produced by adjusting the addition amounts of retention aid and calcium carbonate. Tensile index, burst index, tear index, internal bonding strength of sheets straightly decrease as the ash content of sheets increases. Especially, in the same ash content, all sorts of strength are high in compozil system, low in dual polymer system. Opacity increases along with according to the increase of ash content, and is high in hydrocol system, the worst in dual polymer system. In equal opacity, the strength of paper decreases compozil, hydrocol, and dual polymer system in order. But to judge the superiority or inferiority of retention aids, it should consider the various factors such as the optimum production and process conditions besides the retention amounts of filler and the sheet strength.

Effect of Spiral Elastic Band on Gait Function in Patients with Chronic Stroke

백기현,임형원 대한물리치료학회 2019 대한물리치료학회지 Vol.31 No.4

Purpose: This study examined the effects of a spiral elastic band for the walking function on patients with chronic stroke. Methods: Twenty one chronic stroke patients were recruited and divided randomly into the experimental group and control group. Both groups performed mat exercises and gait training three times a week for four weeks, and gait training was applied to the experimental group with additional spinal elastic bands. Results: The results of this research were as follows. The 10MWT measurements showed that the velocities within and between the groups decreased significantly, and the results of TUG showed significant decreases in velocities after the interventions in both the control group and experimental group. On the other hand, there were no significant differences between the control and experimental group. The FRT measurements showed significantly increased stride lengths within and between the groups. The measurements of the stride length, stride velocity, cadence, and step length showed significant improvement within the groups, but there was no significant difference between the groups. The measurement of stance showed that the non-paralytic patients had a significant increase in the rates within the groups and a significant difference was observed between the groups. Conclusion: Spiral elastic bands are an effective intervention method for rehabilitation programs to enhance the walking function in the clinical field. A treatment needs to be developed for patients with walking problems due to various disorders by investigating the action mechanism of spiral elastic bands.

새로 개발된 부상형 육묘에 있어서 스티로포움 판의 두께가 연초 묘 생육에 미치는 영향

백기현,신승구,한종구,권구홍,김영신,이승철 한국연초학회 1997 한국연초학회지 Vol.19 No.2

The inluence of styrofoam-panel thickness of floating frame on the seedling growth of flue-cured tobacco(Nicotiana tabacum L.) in the newly developed direct-seed float system was investigated . Floating frame used instead of styrofoam-tray consisted of styrofoam-panel (106×108cm) for floating, eight holes(1.Sx2S.0 cm) to uniform the water, and nutrition supply far seedling and water and nutrition absorption cloth placed on the styrofoam-panel. Each floating-frame may lay eight plastic-trays on it. Eight grades of styrofoam-panel thickness from 26 mm to 46mm and two kinds of media were used in the greenhouse system. Dry cells were found from the styrofoam-panel thickness of 43mm in carbonized chaff, compost and original soil rate of L3-3(v/v) media, and of 37mm in peat and perlite rate of 8-2(v/v) media. The thinner styrofoam-panel produced more tender and succulent seedling with the more trunk and the less root weight. When considering the appearance of dry cell, seedling growth, producing healthy tobacco seedlings, and utilization of styrofoam-panel for two kinds of medias the ideal styrofoam-panel thickness were suggested to be around 34mm for flue-cured tobacco reeling production in the newly developed direct-seeding float system. Key words : tobacco seedlings, float system, medium, styrofoam pannel, dry cell.

신문용지 생산에 있어서 국내 신문고지 혼입량 증대에 관한 연구

백기현,김용석,안병준,손상돈 한국펄프종이공학회 1999 펄프.종이기술 Vol.31 No.1

This study was performed to investigate the deinkability of Korean old newspaper(KONP) and the properties of newsprint made from deinked pulp with some addition of virgin pulp. When the samples of composed of 50% Australian old magazine(AuOMG) and 50% KONP were compared with the samples 50% AuOMG and 50% AuONP, the yield, opacity, strength properties of the former were high, but its brightness was low. When the mixing ratio of AuOMG : AuONP : KONP was 30:20:50, the brightness and strength properties were obtained the similar or better than those obtained samples having other mixing ratio. The brightness and opacity of samples made from deinked pulp with the some addition of TMP and BKP can meet the minium qualifications of brightness and opacity specified by Japanese Industrial Standard. The samples, which DIP, TMP, and KP were mixed with the ratio of the 85:10:5 and 90:5:5, maintained higher brightness and strength comparing to the samples containing higher amount of virgin pulp. Since the newsprint samples made from KONP was not inferior to those from imported old newspaper, the more use of KONP in producing newsprint is recommended.

물리적 처리에 의한 신문용지의 컬 변화 - 권취롤의 직경, 저장 기간, 권취 방법, 캘린더링 및 습도의 영향 -

백기현,임연주 한국펄프.종이工學會 2004 펄프.종이기술 Vol.36 No.3

백상고지로부터 표백, 버진펄프와 혼합 및 유연제 처리에 의한 고급화장지 제조

백기현,고경무,남원석 한국펄프.종이工學會 2002 펄프.종이기술 Vol.34 No.4