• Title/Summary/Keyword: vacuum time

Search Result 1,630, Processing Time 0.03 seconds

IGRINS First Light Instrumental Performance

  • Park, Chan;Yuk, In-Soo;Chun, Moo-Young;Pak, Soojong;Kim, Kang-Min;Pavel, Michael;Lee, Hanshin;Oh, Heeyoung;Jeong, Ueejeong;Sim, Chae Kyung;Lee, Hye-In;Le, Huynh Anh Nguyen;Strubhar, Joseph;Gully-Santiago, Michael;Oh, Jae Sok;Cha, Sang-Mok;Moon, Bongkon;Park, Kwijong;Brooks, Cynthia;Ko, Kyeongyeon;Han, Jeong-Yeol;Nah, Jakyuong;Hill, Peter C.;Lee, Sungho;Barnes, Stuart;Park, Byeong-Gon;T., Daniel
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.39 no.1
    • /
    • pp.52.2-52.2
    • /
    • 2014
  • The Immersion Grating Infrared Spectrometer (IGRINS) is an unprecedentedly minimized infrared cross-dispersed echelle spectrograph with a high-resolution and high-sensitivity optical performance. A silicon immersion grating features the instrument for the first time in this field. IGRINS will cover the entire portion of the wavelength range between 1.45 and $2.45{\mu}m$ accessible from the ground in a single exposure with spectral resolution of 40,000. Individual volume phase holographic (VPH) gratings serve as cross-dispersing elements for separate spectrograph arms covering the H and K bands. On the 2.7m Harlan J. Smith telescope at the McDonald Observatory, the slit size is $1^{\prime\prime}{\times}15^{\prime\prime}$. IGRINS has a $0.27^{\prime\prime}$ pixel-1 plate scale on a $2048{\times}2048$ pixel Teledyne Scientific & Imaging HAWAII-2RG detector with SIDECAR ASIC cryogenic controller. The instrument includes four subsystems; a calibration unit, an input relay optics module, a slit-viewing camera, and nearly identical H and K spectrograph modules. The use of a silicon immersion grating and a compact white pupil design allows the spectrograph collimated beam size to be 25mm, which permits the entire cryogenic system to be contained in a moderately sized rectangular vacuum chamber. The fabrication and assembly of the optical and mechanical hardware components were completed in 2013. In this presentation, we describe the major design characteristics of the instrument and the early performance estimated from the first light commissioning at the McDonald Observatory.

  • PDF

A study of the Mori Radicis Cortex pre-treatment on transient ischemic brain injury in mice (상백피(桑白皮) 메탄올 추출물 전처치가 일과성 허혈에 의한 생쥐의 뇌 손상에 미치는 영향)

  • Chung, Byung-Woo;Lim, Jae-Yu;Lee, Se-Eun;Lee, Byoungho;Lim, Sehyun;Lim, Chiyeon;Cho, Suin
    • The Korea Journal of Herbology
    • /
    • v.32 no.1
    • /
    • pp.25-31
    • /
    • 2017
  • Objectives : Mori Radicis Cortex (MRC), the root epidermis of Morus alba L., has been traditionally used to treat lung-related diseases in Korean Medicine. The common of MRC is Mulberry bark Morus bark, and it's pharmaceutical properties and taste are known as sweet and cold, and it promotes urination and reduce edema by reducing heat from the lungs and soothe asthma. In the present study, anti-apoptotic mechanism of MRC in middle cerebral artery occlusion (MCAO) model in mice. Methods : Two-hundred grams of MRC was extracted with methanol at room temperature for 5 days, and this was repeated one time. After filtration, the methanol was removed using vacuum evaporator, then stored at $-20^{\circ}C$ until use. C57BL/6 male mice were housed in an environment with controlled humidity, temperature, and light cycle. In order to determine beneficial effects of MRC on ischemia induced brain damage, infarct volume, neurological deficit scores, activities of several apoptosis-related proteins such as caspase-8, -9, Bcl-xL in MCAO-induced brains of mice were analyzed. Mice in MRC-treated groups were orally administered 30, 100, or 300 mg/kg of body weight for three consecutive days before commencing the MCAO procedure. Results : Pre-treatment of MRC significantly reduced infarct volume in MCAO subjected mice applied with 300 mg/kg of MRC methanol extract, and MRC effectively inhibited Bcl-xL reduction and caspase-9 activation caused by MCAO-induced brain damage. Conclusions : MRC showed neuro-protective effects by regulating apoptosis-related protein signals, and it can be a potential candidate for the therapy of ischemia-induced brain damage.

Effect of Modified Atmosphere Packaging on Preservation of Pumpkin Rice Cake (호박 설기떡의 저장성에 미치는 변형기체포장의 영향)

  • Moon, Ki-Bok;Kim, Hwan-Ki;An, Duck-Soon;Lee, Dong-Sun
    • Food Science and Preservation
    • /
    • v.17 no.6
    • /
    • pp.908-913
    • /
    • 2010
  • Modified atmosphere packaging (MAP) was evaluated for the storage of pumpkin rice cake as a means of preserving quality and extending shelf-life. Retail-sized amounts of rice cake were packaged in trays under different modified atmosphere conditions (air, vacuum, 60% $CO_2$/40% $N_2$ and 100% $CO_2$) using gas-barrier plastic film; control was in air-permeable stretch wrap. The packages were stored at $20^{\circ}C$ with periodical measurement of package atmosphere and cake quality attributes. The modified atmosphere packages of 60% $CO_2$/40% $N_2$ and 100% $CO_2$ inhibited the growth of molds/yeasts completely and significantly retarded the growth of aerobic bacteria. All the packages except that of 100% $CO_2$ showed the reduction of internal $O_2$ concentration and increase of the $CO_2$ with storage time due to the microbial activity. There has been slight decrease of $CO_2$ concentration for 60% $CO_2$/40% $N_2$ and 100% $CO_2$ packages just after start of the storage possibly due to dissolution of headspace $CO_2$ into the cake. Any MAP conditions did not affect the retrogradation of the rice cake. Surface color of the cake within affordable microbial quality limit was not affected significantly by packaging conditions.

Magenetic Properties of Nd-Fe-B-Co-based Melt-spun Ribbons an dTheir Bonded Magents (Nd-Fe-B-Co계 급냉리본과 Bond 자석의 자기적 성질)

  • Gang, Gye-Myeong;Gang, Gi-Won;O, Yeong-Min;Song, Jin-Tae
    • Korean Journal of Materials Research
    • /
    • v.3 no.2
    • /
    • pp.175-184
    • /
    • 1993
  • Abstract Co-and/or AI-added Nd-Fe-B-based magnetic alloys were fabricated by using vacuum induction melting frunace, and melt-spun ribbons were made of the magnetic alloys with single roll rapid quenching method. The variation of magnetic properties of the melt-spun ribbons as a function of Cuwheel velocity (Vs) were investigated. Bonded magnets were made of the optimally quenched ribbon fragments, and the magnetic properties of the melt-spun ribbons and the bonded magnets were studied, relating to the microstructure and crystalline structure. Cu-wheel surface velocity had a strong effect on the magnetic properties of the melt-spun ribbons, and the maximum properties were obtained around Vs =20m/sec. The optimally quenched ribbon had a cellura-type microstructure, in which fine N$d_2$F$e_14$B grains were surrounded by thin Nd-rich phase. In case of a 2.1at% AI-added melt-spun ribbon, the magnetic properties were as follows: iHc, Br, and (BH)max were 15.5KOe, 7.8KG and 8.5MGOe respectively. And resin bonded magnets were fabricated by mixing optimally quenched ribbon fragments with 2.5wt % polyamide resin, compacting and binding at room temperature. The iHc, Br and (BH)max of bonded magnet were lO.2KOe, 4.4KG and 3.3MGOe respectively. And hot-pressed magnets were made by pressing the overquenched ribbons at high temperature. The magnetic properties of hot-pressed magnets were better than those of bonded magnets, and when the holding time was 8 minutes, the iHc, Br, and (BH)max of the hot-pressed magnet were 1O.8KOe, 7.3KG and 8.0MGOe respectively. Domain structure was mainly maze pattern, which means that the easy magnetization axis could be aligned, and the domain width of the hot-pressed magnets was smaller than that of bonded magnets.

  • PDF

Production and High Temperature Mechanical Properties of Ti-TiC Composite by Reaction Milling (반응밀링법에 의한 Ti-TiC 복합재료의 제조 및 고온 기계적 특성)

  • Jin, Sang-Bok;Choe, Cheol-Jin;Lee, Sang-Yun;Lee, Jun-Hui;Kim, Sun-Guk
    • Korean Journal of Materials Research
    • /
    • v.8 no.10
    • /
    • pp.918-924
    • /
    • 1998
  • This study has been carried out to investigate the effect of reaction milling time on the synthesis of Ti- TiC p powder synthesised from the elemental titanium and activated carbon by reaction milling(RM), and the effect of vacu­u urn hot pressing temperature and TiC volume fraction on microstructural and mechanical properties of Ti- TiC com­p posite $\infty$ns이idated by vacuum hot pressing(VHP).T The elemental powders of titanium and activated carbon can be converted into Ti- TiC composite powders by reac­t tion milling for about 300hours, and were the average grain size of the as- milled powders has been measured to be a about $5\mu\textrm{m}$. The relative density of Ti- TiC VHPed above $1000^{\circ}C$ during Ihr is about 98% and the mechanical properties o of In- situ Ti- TiC composites are improved by TiC particle dispersed uniformly on titanium matrix. In order to investi­g gate thermal stability of Ti- TiC composite, after annealing at $600^{\circ}C$ for 80hrs micro- Vickers hardness have been per­f formed, and the values have been shown little changed as compared with those before annealing. The compact has b been tested on high temperature compressive test at $700^{\circ}C$ and has showed a high temperature compressive strength of 330MPa in a Ti- 20vol% TiC.

  • PDF

Photoluminescence Characteristics of Spherical-Shaped LaPO4:Tb Phosphor Particles Prepared by Spray Pyrolysis (분무열분해법에 의해 제조된 구형의 녹색 LaPO4:Tb 형광체의 발광특성)

  • Lee, Kyo-Kwang;Kang, Yun-Chan;Zeon, Il-Woon;Jung, Kyeong-Youl;Park, Hee-Dong
    • Korean Journal of Materials Research
    • /
    • v.12 no.9
    • /
    • pp.761-766
    • /
    • 2002
  • Fine $LaPO_4$:Tb phosphor particles with spherical shape were prepared by spray pyrolysis. The influence of the precursor type of phosphorous such as ($NH_4$)$_2$$HPO_4$, $NH_4$$H_2$$PO_4$, ($NH_4$)$_3$$PO_4$ and $H_3$$PO_4$ on the morphology and brightness of particles was investigated. As-prepared particles by spray pyrolysis had spherical shape when ($NH_4$)$_2$ $HPO_4$ and $NH_4$$H_2$$PO_4$ were used as the precursor of phosphorous. The precursor type of phosphorous affected the photoluminescence intensity of $LaPO_4$:Tb phosphor particles, but not significant. With changing the content of activator(Tb) and excess of phosphorous, the optimal composition giving the highest photoluminescence intensity was found. The spherical morphology of prepared $LaPO_4$:Tb particles was completely maintained even after the posttreatment up to $1050^{\circ}C$. When the posttreatment temperature was over $1100^{\circ}C$, the particles did not have the spherical shape anymore. However, the highest photoluminescence intensity of prepared $LaPO_4$:Tb particles was obtained at $1050^{\circ}C$. The photoluminescence characteristics of prepared $_LaPO4$:Tb under the vacuum ultraviolet(VUV) illumination was comparable with that of the commercial $Zn_2$$V_4$:Mn and (La,Ce)PO$_4$:Tb phosphor particles. At the optimal condition, the decay time of prepared spherical $LaPO_4$:Tb phosphor particles was about 6.8ms.

Relationship between Maternal Work Activity and Congenital Muscular Torticollis (어머니의 직업활동이 선천성 근육사경에 미치는 영향)

  • Kim, Ki-Jeon;Song, Brian Byung
    • The Journal of the Korea Contents Association
    • /
    • v.13 no.9
    • /
    • pp.270-280
    • /
    • 2013
  • The Purpose of this study was to investigate the relationship between congenital muscular torticollis and maternal work activity. This study was conducted with a total of 89 outpatient pregnant women whose child presented congenital muscular torticollis at the Department of Rehabilitation of "C" Hospital in Suwon within the period from 2006 to April 30, 2011. The results were as followings: (1) The mean age at the time of giving birth was 30.09years; the proportion of pregnant women with college education or higher was high; the proportion of first delivery was 82.0%; the most common way of delivery was natural childbirth, followed by Cesarean section and vacuum extraction; the proportion of breech delivery was 20.2%; and in 82.0% of the women, the first child had congenital muscular torticollis. (2) 59.6% of the women had a career; 45.3% had engaged in professional practice or had a related job; 75.5% had worked until the third trimester of their pregnancy; 54.7% had worked for seven hours or more in a seated position; and the mean number of working hours was 8.75 (3) The level of work-related stress was a low 25% or less, and in the subdivisions of work-related stress, only the level of strained relations belonged to the upper 50% or higher. (4) For the correlation between the survey respondents' job stress and job features, stress (full score: 100 points) showed a strong positive correlation with job demand, strained relations, inadequate reward, and workplace culture. Workplace also showed a strong positive correlation with inadequate reward. Mean daily working hours showed a strong positive correlation with mean weekly working hours.

Treatment of Venous Stasis Ulcer with $3M^{TM}$ $Coban^{TM}$ 2 Layer Compression System: A Case Report (두겹 압박방식 $3M^{TM}$ $Coban^{TM}$을 이용한 울혈성 정맥궤양의 치료: 증례보고)

  • Chu, Ho-Jun;Son, Dae-Gu;Kim, Jun-Hyung;Han, Ki-Hwan;Kim, Hyung-Tae
    • Archives of Plastic Surgery
    • /
    • v.38 no.5
    • /
    • pp.699-702
    • /
    • 2011
  • Purpose: Venous stasis ulcer is the most severe form of chronic venous insufficiency and this commonly appears in the lower limb. Pharmacological therapy, reconstruction of the venous system, surgical management, cellular therapy and compression therapy are known as the treatments of venous stasis ulcer, but relapses are common, which make it a typical chronic wound. We report here on a case of recurrent venous stasis ulcer that healed with compression therapy without any other treatment. Methods: A 35-year-old man with a 13 years history of venous stasis had developed an ulcer on the distal third portion of the lower left limb which was developed 12-year before enrollment in this study. He had been treated with vacuum assist closure, 2 times of cell therapy and 3 times of skin graft for 8 years, but the lesion recurred. From November, 2008 compression therapy was done with the 3M $Coban^{TM}$ 2 Layer Compression System (3M, St. Paul, USA). The ulcer at that time was oval shaped and $3{\times}4$ cm in size. A comfort layer bandage was applied from the proximal phalanx of the great toe to the knee. A compression layer bandage was applied on the previous layer with it being overlapped one half the width of the comfort layer bandage. The dressing was changed every 4 days and the change was recorded with photography. Results: A total of 12 $Coban^{TM}$ 2 Layer Compression Systems were used. The size of the ulcer decreased to $2.5{\times}2.5$ cm in one month, to $2{\times}2$ cm in 2 months, it was $1{\times}1.8$ cm in size at 3 months and it completely healed in 4 months. Conclusion: The venous stasis ulcer was completely healed using the 3M $Coban^{TM}$ 2 Layer Compression System. This method was easy to apply, made the patient comfortable and it provided an excellent compression effect. As in the previous studies, this compression therapy has been proven to play an important role for the treatment and prevention of venous stasis ulcer.

Evaluation of the Addition of Sodium Lactate and a Fat Replacer in Very Low-fat Bologna (model system) on the Product Quality and Shelf-life Effect during Refrigerated Storage (젖산나트륨과 지방대체제의 첨가가 냉장저장 중 저지방 볼로나 소시지의 품질 및 저장성에 미치는 영향)

  • 진구복;최순희
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.30 no.5
    • /
    • pp.858-864
    • /
    • 2001
  • This study was performed to investigate the effect of sodium lactate (SL, 60%) and a mixed fat replacer (FR) on the product quality and shelf-life effect of low-fat bologna sausage (LFBS) in a model system during refrigerated storage. Low-fat and regular-fat bologna sausages had pH values ranged from 6.15 to 6.30 and water activity values ranged from 0.95 to 0.96. LFBS had a moisture content of 74~76%, <2% fat and 14~15% protein, whereas regular-fat bologna had 60% moisture, 22% fat and approximately 12% protein in the final products. Expressible moisture (%) increased (p<0.05) in all bolognas, resulting in the soft texture, as the storage time (weeks) increased. LFBS manufactured with SL and a FR had lower (p<0.05) the cooking loss (%) and had higher (p<0.05) texture profile analysis (TPA) values than the regular-fat counterpart. As the sodium lactate level increased up to 5% in the formulation of LFBS, vacuum purge and TPA hardness values also increased (p<0.05), but thiobarbituric acid (TBA) values decreased (p<0.05). Total plate counts of LFBS were reduced (p<0.05) when the addition level of 60% SL solution was more than 3.3%. This result indicated that the increased level of SL (>3.3%) in the combination of a FR in the formulation of LFBS improved the product quality and did inhibit the total microbial growth of LFBS during storage, as compared to the control.

  • PDF

The Base Catalyzed Synthesis of Sucrose Ester Containing Omega-3 Fatty Acids (오메가 3 지방산을 함유한 Sucrose Ester의 합성)

  • Shin, Jung-Ah;Jang, Ji-Sun;Hong, Jang-Hwan;Lee, Ki-Teak
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.35 no.9
    • /
    • pp.1224-1231
    • /
    • 2006
  • Sucrose esters were synthesized by transesterification of sucrose with docosahexaenoic acid ethylester mixture (DHAEE). Potassium carbonate as a base catalyst was used in the presence of dimethylsulfoxide (DMSO) for the reactions. The reactions were performed with the different reaction times and molar ratios of substrates in the presence of surfactant in vacuum. Among the reaction conditions in this study, SE#4~7 showed the relatively high conversion rate (>96%) of DHAEE, leading to the high yield of sucrose esters. In addition, the product composition was changed from sucrose mono ester to di/tri/polyesters after the prolonged reaction time while the increased molar ratio of DHAEE also resulted in the composition changes of sucrose mono ester to the sucrose di/tri/polyesters. From the reaction (SE#7), conversion ratio was 98.5% in which 87.3% mono ester and 13.7% di/tri/polyester were found, resulting in the highest content of mono ester. Therefore, the sucrose ester containing various rates of mono and di/tri/polyesters, which effects on hydrophilic lipophilic balance (HLB) values, can be manipulatively synthesized using the reaction conditions reported in this study.