• 대한수의학회지
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• 제47권1호
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• pp.117-125
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• 2007

Bone graft had been investigated previously to restore bone defects in orthopedics. The purpose of this study was to investigate the efficacy on new bone formation in bone autografts by treatment of implants. Cortical bone autografts were transplanted to midshaft of diaphyseal fibulae of 9 rabbits which were divided in 3 groups according to the treatment method of implants. Cortical bone implants for graft were treated with 3 different methods; freezing, freeze-drying, defat-freezing. Autografts were achieved by cross-transplantation method to bilateral fibulae of the presented rabbits after implant treatment procedures. The grafted regions of fibulae of all groups had been radiographed biweekly for 16 weeks to observe new bone formation and union between donor and recipient bone in the grafted region. Bone alkaline phosphatase (BALP) in all groups was evaluated biweekly till the end of the experiment to determine osteoblast activities. Unions of the experimental grafted regions were observed at 83% (5 of 6 cases) of freezing, 17% (1 of 6 cases) of freeze-drying and 67% (4 of 6 cases) of defat-freezing autografts, respectively. BALP was increased over 100% after 2 weeks of graft procedures in all union cases (all cases in freezing group and in defat-freezing group, and 1 of 3 in freeze-drying group, respectively), then gradually decreased from 4 th week of graft to 16 th week. In non-union cases, there is no significant variation in BALP value until the end of experiment. It is speculated that defat-freezing method of treatments of implants is more safe to preserve the osteogenic ability in autograft than freeze-drying method.

• 한국임상수의학회지
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• 제24권3호
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• pp.350-357
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• 2007

Bone graft had been widely investigated for reconstruction of bone defects or acceleration of bone healing in orthopedics, neurosurgery and dental surgery. Autograft is the golden standard of bone graft but it is associated with donor site morbidity and is restricted in quantity. Xenograft has been researched an alternative method for autograft. The purpose of this study was to investigate the efficacy of new bone formation according to three different preparations of implants on rabbit xenograft. Cortical bone xenografts which made from bovine femoral cortical bone were treated by freezing, freeze-drying or defat-freezing implant preparations. They were transplanted into proximal diaphyseal shaft of bifibulae of 15 rabbits which were divided into three groups according to their implant preparation method. The fibulae transplantations were evaluated radiographically and examined osteoblast activity by bone alkaline phosphatase (BALP) biweekly for 16 weeks to observe new bone formation and union of the experimental defected region. New bone formation was observed in 7 cases in freeze-drying and defat-freezing group, respectively. Union of proximal and distal end of defected region, which was considered as success of bone graft, was observed in 4 cases (40%; 4 of 10 cases), respectively. In freezing group, new bone formation was observed in 6 cases but, there is no union observed. BALP value was increased over twice after two weeks of graft procedure in all union cases of freeze-drying and defat-freezing group (two of five animals, respectively) then gradually decreased to 16th week. In non-union cases, there is no significant variation in BALP value. Defat-freezing or freeze-drying preparations of implants are more efficacious in new bone formation than freezing method on rabbit xenograft. While it is difficult to propose which is superior between defat-freezing and freeze-drying, defatting of implants may enhance new bone formation in xenograft.

• 한국건축시공학회지
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• 제13권3호
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• pp.202-208
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• 2013

The method used to test lightweight aggregate concrete for its resistance to freezing and thawing is different in each country. In Korea, the method of KS F 2456 on normal concrete is adopted for lightweight aggregate concrete, while the testing method of ASTM C 330 lightweight aggregates for structural concrete is used in the majority of overseas countries. In this study, we identified differences between KS F 2456 and ASTM C 330 in terms of the testing method for freezing and thawing resistance, and we studied the influence of this on the freezing and thawing resistance of lightweight aggregate concrete. The results of this study were as follows: Blocked lightweight aggregates had a slight collapse of shape and lost weight by repeated freezing and thawing, but unblocked lightweight aggregates were badly collapsed. And while the freezing and thawing resistance tests of normal concrete showed similar results despite the difference in the KS and ASTM testing method, the results for lightweight aggregate concrete were very different. So the KS test method shows evaluation results that are much lower than the ASTM test method.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.150-154
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• 2008

In this research, stress components and principal stresses of O-ring under internal pressure and under uniform squeeze rate were obtained from the stress freezing method of photoelastic experiment and photoelastic experimental Hybrid method for 3-dimensional problems. The obtaining processes of those were introduced. It was certified that the processes of those are effective for the 3-dimensional stress analysis of structures. Stress freezing method, the obtaining processes of those and photoelastic experimental hybrid method were effectively applied to the stress analysis of O-ring made from rubber that under uniform deformation and internal pressure. Stress components and principal stress of Oring under uniform squeeze rate and under internal pressure were analyzed.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 전기학술대회논문집
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• pp.233-238
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• 2005

According to change of flow around a circular tube for freezing, measured a variety of salinity of frozen layer. This study was experimentally performed to investigate freezing behavior of sea water along a vertical cooled a circular tube with bubbly flow. The experiments were carried out for a variety of parameter, such as air-bubble method, cooled -tube temperature and air-flow rate. It was found that the experimental parameters gave a great influence on the freezing rate and the salinity of the frozen layer.

• 대한수의학회지
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• 제47권2호
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• pp.219-228
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• 2007

Bone allograft had been increased the need because autogenous bone graft is associated with donor site morbidity and is restricted in quantity. The bone allograft implants have to prepare properly for increasing osteoinductive ability and decreasing immune responses before providing to graft. The purpose of this study was to investigate the efficacy on new bone formation in bone allografts by treatment of implants. Cortical bone allografts were transplanted to experimental defects on midshaft of diaphyseal fibulae in 15 rabbits, which were divided to 3 experimental groups according to the preparation methods-freezing, freeze-drying, defat-freezing. The grafted regions of fibulae of all groups had been radiographed biweekly for 16 weeks to observe new bone formation and union between implant and recipient bone. Bone Alkaline Phosphatase (BALP) in all groups was evaluated biweekly till the end of the experiment to determine osteoblast activities. Unions between implant and recipient bone were observed at 30% (3 of 10 cases) of freezing, 50% (5 of 10 cases) of freeze-drying and 80% (8 of 10 cases) of defat-freezing. BALP was increased over 100% from before graft at 2 weeks of graft procedures in all union cases of freezing and defat-freezing group, then gradually decreased till 16th week. In non-union cases, there is no significant variation in BALP value. Defat-freezing method for allograft implants might be more effective for osteoinductive efficacy of implants than freezing and freeze-drying method.

• 한국식품조리과학회지
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• 제32권6호
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• pp.665-676
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• 2016

Purpose: This study was conducted to find the optimal freezing method and storage conditions for welsh onion. Methods: Cut welsh onions (0.3 cm) were packed in nylon/linear low density polyethylene (LLDPE) film bags, and frozen utilizing still-air freezing at -$20^{\circ}C$ (SAF20) and -$40^{\circ}C$ (SAF40), and immersed-liquid freezing at -$40^{\circ}C$ (ILF40); they were then stored at -$20^{\circ}C$ for 7 months. During storage, quality characteristics were measured monthly. Results: Drip loss was the lowest in the ILF40 packaging. Color difference in the stem (white part) did not differ significantly according to freezing conditions and storage time. Color difference in the leaf (green part) and stem was the lowest in SAF20. pH remained unchanged, while total aerobic bacterial count, pyruvic acid and moisture content decreased during storage. Pyruvic acid content of ILF40 was the highest among the freezing treatments. Fructose and glucose contents increased gradually during storage. Citric acid, malic acid, succinic acid and fumaric acid contents were unaffected, regardless of the freezing conditions. Conclusion: The optimal freezing method for welsh onions with the least quality changes was determined to be immersed liquid freezing, following by preservation up to 7 months by freeze-storing.

• 한국발생생물학회지:발생과생식
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• 제2권1호
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• pp.63-68
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• 1998

본 연구에서는 보다 효율적인 동결 보존법을 수립하기 위하여 현재 사용되는 동결 보존액과 동결방법을 정자의 운동성 측면에서 비교해 보았다. 즉, 세 종류의 조성이 다른 동결보존액인 TYB, dithiothreitol을 첨가한 TYB+DTT, KS II 등이 동결보존 전후에 있어 운동성에 미치는 영향을 조사하였으며, 또한 vapor freezing 방법과 computerized freezer를 사용한 동결방법이 정자 운동성에 미치는 영향을 알아보았다. 정자의 분석은 현미경적 방법과 두 종류의 컴퓨터 정자 자동측정기인 SAIS와 Hamilton Thorn을 사용하여 동결 전 후의 정자 운동성과 VCL, VSL, VAP, ALH, LIN 등의 sub-motility 패턴을 측정하였다. 정액성상이 정상인 군에서 동결보존액을 비교한 실험결과는 TYB군과 TYB+DTT군, 그리고 KS II군의 융해 후 운동성이 각각 28.3%, 23.0%, 34.8%로 KS II군이 우수하였고, 동결방법을 비교한 실험에서는 vapor freezing 군과 computerized freezing 군의 융해 후 정자 운동성이 각각 27.8%, 33.2%로 유의차는 없었다. 또한 무력정자증을 보인 정액군에서는 TYB군과 TYB+DTT군, 그리고 KS II군에서 융해후 정자 운동성이 각각 13.6%, 10.0%, 18.5%로 여기 KS II군이 우수하였으며, vapor freezing군과 computerized freezing군의 융해 후 정자 운동성은 12.8%, 12.9%로 유의차가 없었다. 이상의 결과로 보아 운동성이 정상인 정액군과 무력정자증을 보이는 정액군에서 KS II를 사용해 동결하는 것이 TYB나 TYB+DTT를 사용하는 것보다 운동성 있는 정자를 회수하는데 더 효율적이며, 동결방법 측면에서는 vapor freezing 방법과 computerized freezing방법간에 큰 차이가 없음을 볼 수 있었다.

• Journal of Chest Surgery
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• 제36권4호
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• pp.219-228
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• 2003

배경: 액체질소에 의한 냉동방법은 생물학과 의학에서 세포와 조직의 장기보존으로는 성공적인 방법이다. 잘 조절된 냉동속도와 해동의 방법과 함께 글라이세롤이나 디메칠설폭사이드 같은 냉동보존제의 사용으로 얼음결정이 생기는 것을 방지하여 구조의 유지와 생존율을 모두 향상시킬 수 있으며 반영구적으로 보존할 수 있다. 여러 조직의 초저온냉동에는 조직에 맞는 냉동속도가 있다. 대상 및 방법: 가장 적합한 냉동곡선과 이를 위한 냉동챔버온도를 찾기 위해서 우리들은 조직의 열역학적 계산을 두 가지 방법으로 하였다. 하나는 직접계산방법으로 모든 냉동 대상물의 열물리학적 특성, 잠재용융열, 면적, 농도와 체적을 알아야 계산할 수 있다. 이러한 방법은 매우 복잡하고 어떠한 경우에는 실제 값을 알 수 없다. 다른 방법은 간접계산방법으로 우선 기존의 냉동곡선으로 조직을 냉동시켜 조직의 실제 냉동곡선을 얻은 다음 시간상수로 냉동곡선을 분석한 다음 온도반응을 계산하고 적합한 x차방정식을 대입시켜 냉동 시 온도상승을 막고 이것을 거꾸로 냉동챔버온도를 산출하는 방식이다. 결과: 이 냉동 프로그램을 중배엽줄기세포, 연골세포와 골아세포에 적용시켜 검사하였다. 조직의 온도는 온도상승과정 없이 이상적인 냉동곡선을 따라 감소하였다. 그러나 세포의 양과 수용액의 양이 적어 냉동곡선간의 생존력이 통계학적으로 차이가 있지는 않았다. 만약 더욱 부피가 큰 조직을 냉동시키거나 프로그램을 순차적으로 계속한다면 이상곡선에 더욱 근접하게 되어 차이가 있을 것으로 판단된다. 결론： 이 프로그램은 이상적인 냉동곡선으로 조직을 냉동시키기 위한 냉동챔버온도를 쉽게 찾을 수 있도록 도움이 될 것이다.

• 한국축산식품학회지
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• 제36권5호
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• pp.650-655
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• 2016

This study investigated the effects of artificial supercooling followed by still air freezing (SSF) on the qualities of pork loin. The qualities of pork frozen by SSF were compared with the fresh control (CT, stored at 4℃ for 24 h), slow freezing (SAF, still air freezing) and rapid freezing (EIF, ethanol immersion freezing) treatments. Compared with no supercooling phenomena of SAF and EIF, the extent of supercooling obtained by SSF treatment was 1.4℃. Despite that SSF was conducted with the same method with SAF, application of artificial supercooling accelerated the phase transition (traverse from -0.6℃ to -5℃) from 3.07 h (SAF) to 2.23 h (SSF). The observation of a microstructure indicated that the SSF prevented tissue damage caused by ice crystallization and maintained the structural integrity. The estimated quality parameters reflected that SSF exhibited superior meat quality compared with slow freezing (SAF). SSF showed better water-holding capacity (lower thawing loss, cooking loss and expressible moisture) and tenderness than SAF, and these quality parameters of SSF were not significantly different with ultra-fast freezing treatment (EIF). Consequently, the results demonstrated that the generation of supercooling followed by conventional freezing potentially had the advantage of minimizing the quality deterioration caused by the slow freezing of meat.