• 제목/요약/키워드: capsulation

검색결과 56건 처리시간 0.021초

PCM 혼입 경량기포콘크리트 패널 개발을 위한 기초적 연구 ((An) experimental study on the development of lightweight concrete using the PCM)

  • 임명관;오돈투야;김영호;최동욱
    • KIEAE Journal
    • /
    • 제14권4호
    • /
    • pp.133-138
    • /
    • 2014
  • The present study was carried out to assess the basic material properties and thermal behavior of light-weight foamed concrete panel mixed with PCM (Phase Changing Material). To do so, this study fabricated light-weight foamed concrete (1.0kg/m3) in pre-foaming method and mixed it with PCM micro capsule of 1-dodecanol and melamine to examine its physical and thermal properties. The results confirmed strength reinforcement effect by proper replacement ratio of fly-ash, which is an industrial by-product, and PCM. In addition, it found out that PCM-mixed light-weight foamed concrete had time delay and temperature reduction effect within the range of PCM phase transition according to the rise of outdoor temperature. It was also observed that the insulation performance of PCM-mixed light-weight foamed concrete was more dependent upon thickness than PCM replacement ratio.

Status, Antimicrobial Mechanism, and Regulation of Natural Preservatives in Livestock Food Systems

  • Lee, Na-Kyoung;Paik, Hyun-Dong
    • 한국축산식품학회지
    • /
    • 제36권4호
    • /
    • pp.547-557
    • /
    • 2016
  • This review discusses the status, antimicrobial mechanisms, application, and regulation of natural preservatives in livestock food systems. Conventional preservatives are synthetic chemical substances including nitrates/nitrites, sulfites, sodium benzoate, propyl gallate, and potassium sorbate. The use of artificial preservatives is being reconsidered because of concerns relating to headache, allergies, and cancer. As the demand for biopreservation in food systems has increased, new natural antimicrobial compounds of various origins are being developed, including plant-derived products (polyphenolics, essential oils, plant antimicrobial peptides (pAMPs)), animal-derived products (lysozymes, lactoperoxidase, lactoferrin, ovotransferrin, antimicrobial peptide (AMP), chitosan and others), and microbial metabolites (nisin, natamycin, pullulan, ε-polylysine, organic acid, and others). These natural preservatives act by inhibiting microbial cell walls/membranes, DNA/RNA replication and transcription, protein synthesis, and metabolism. Natural preservatives have been recognized for their safety; however, these substances can influence color, smell, and toxicity in large amounts while being effective as a food preservative. Therefore, to evaluate the safety and toxicity of natural preservatives, various trials including combinations of other substances or different food preservation systems, and capsulation have been performed. Natamycin and nisin are currently the only natural preservatives being regulated, and other natural preservatives will have to be legally regulated before their widespread use.

Graphene nanosheets encapsulated poorly soluble drugs with an enhanced dissolution rate

  • Shen, Shou-Cang;Ng, Wai Kiong;Letchmanan, Kumaran;Lim, Ron Tau Yee;Tan, Reginald Beng Hee
    • Carbon letters
    • /
    • 제27권
    • /
    • pp.18-25
    • /
    • 2018
  • In this study, graphene oxide(GO) was used as drug carriers to amorphize poorly watersoluble drugs via a co-spray drying process. Two poorly water-soluble drugs, fenofibrate and ibuprofen, were investigated. It was found that the drug molecules could be in the graphene nanosheets in amorphous or nano crystalline forms and thus have a significantly enhanced dissolution rate compared with the counterpart crystalline form. In addition, the dissolution of the amorphous drug enwrapped with the graphene oxide was higher than that of the amorphous drug in activated carbon (AC) even though the AC possessed a larger specific surface area than that of the graphene oxide. The amorphous formulations also remained stable under accelerated storage conditions ($40^{\circ}C$ and 75% relative humidity) for a study period of 14 months. Therefore, graphene oxide could be a potential drug carrier and amorphization agent for poorly water-soluble drugs to enhance their bioavailability.

환경친화적인 무기/유기 Core-Shell의 제조에 관한 연구 (A Study on the Environmental Fraternized Preparation of Inorganic/organic Core-shell Binder)

  • 설수덕;임재길;임종민;권재범;이내우
    • 한국안전학회지
    • /
    • 제19권1호
    • /
    • pp.81-87
    • /
    • 2004
  • Composite particles using inorganic and organic chemicals were synthesized and the results of those reaction were compared to variation of temperature and agitation speed in presence of $CaCO_3$ which was adsorbed SDBS. Also the synthesises were optimized according to conversion rate of composite particles. In inorganic/organic core-shell composite particle polymerization, $CaCO_3$ adsorbed by 0.5wt% surfactant SDBS was prepared initially and then core $CaCO_3$ was encapsulated by sequential emulsion polymerization using MMA at the addition of APS 3.16${\times}$$10^{-3}$mol/L to minimize the coagulated PMMA particle itself during MMA shell polymerization. Encapsulated PMMA on $CaCO_3$ as inorganic/organic core-shell particles was verified by FT-IR and DSC analysis. It was found that the $CaCO_3$ was very well encapsulated by PMMA as shell. The surfaces were distinctly found as spindle shape and broad particle distribution after capsulation.

소의 탄저기종저 불활화 혼합백신에 관한 연구 (Studies on Inactivated Combined Vaccine of Bovine Anthrax and Blackleg)

  • 전윤성
    • 대한수의학회지
    • /
    • 제10권1호
    • /
    • pp.5-10
    • /
    • 1970
  • Due to the fact that an inactivated anthrax vaccine may lark its immunogenicity and stability of immunogen a number of spore vaccines were exclusively used worldwide. In these studies a number of important factors were emphasized to achieve the following: selection of non or less allergic strain of anthrax bacillus, capsulation of bacteria. obtaining of non sporulating but vegetative organisms, adequate inactivation of B. anthraccis by means of formalin, adsorption of immunogen to aluminum hydroxide gel. Non or less allergic strains of anthrax bacillus which is inactivated with formalin was selected by a hyperimmunization and shock test in rabbits. Obtaining capsular material and vegetative immunogen, a virulent anthrax organisms were cultivated on sodium bicarbonate medium with of without adding of l-alanine in which B, anthracis grew luxuriantly without forming spores. Inactivation was carried out at $37^{\circ}C$ water bath for 3 days after the bacterial culture was mixed with formalin, in a final concentration of two per cent of formalin. Aluminum hydroxide gel was added to the mixture of anthrax and blackleg bacterin. Vaccines were injected guinea pig via subcutaneous or intramusoular route and challenged after three weeks and the possibilities of protection was tested. Throughout the studies. the above mentioned vaccines possibly protected the vaccinated guinea pigs more than 80 per cent compared to that of the controls. This experimental results strongly suggest that the vaccine may possibly applicable to bovine.

  • PDF

이하선 천엽에 발생한 지방종의 치험례 (Lipoma on superficial lobe of the parotid gland: case report)

  • 김정한;김철훈;김민구;송진우;정유진;김복주
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • 제36권5호
    • /
    • pp.438-440
    • /
    • 2010
  • A lipoma is a benign tumor of matured adipose tissue that usually occurs at the shoulder, back, and abdomen. 13% of lipomas occur in the head and neck area. However, the incidence of lipoma in the parotid gland is very low, approximately 2.5%. A conservational surgical excision is recommended in cases of lipoma of the parotid gland, with only 1-2% of lipomas recurring. We report a case of a lipoma in the parotid gland that was removed by conservational surgical excision. The lesion was exposed by the pre-auricular approach and the tissue was detached. After the parotid gland envelop was exposed, a yellowish mass is observed that was easy to remove due to capsulation. Most authors recommend a surgical excision of the superficial lobe of the parotid gland as the treatment for a lipoma in the parotid gland. However, enucleation only may be a sufficient treatment when a lipoma occurs in the superficial lobe or around the parotid gland. A patidectomy is not needed when a lipoma is located at the superficial lobe of the parotid gland, and a conservational surgical excision is suitable. Therefore, a clinical diagnosis is important for reducing the damage to the facial nerve.

VPN을 적용한 인터넷 전화 단말기의 성능평가에 관한 연구 (Study on Eveluation of Performancen on Internet Phone(VoIP) using the VPN)

  • 이성기;유승선;이명재;곽훈성
    • 한국통신학회논문지
    • /
    • 제30권6A호
    • /
    • pp.445-454
    • /
    • 2005
  • 암호화된 인터넷 전화 단말기의 통화품질 측정을 하기위해 실험환경을 구성하여 캡슐화에 따른 지연을 실험한 결과 구현 인터넷 전화기와 일반 VoIP 전화기와의 지연시간의 차이는 최대 5ms 이하였다. 이러한 지연시간의 대부분은 VPN의 터널링을 위한 패킷 캡슐화에 소요되는 지연시간으로 예상할 수 있다. 따라서 일반 VoIP 전화기와 본 연구에서 제시한 VPN을 적용한 VoIP 전화기와의 통화품질의 차이는 무시할 만하였다. 또한 하나의 패킷당 프레임 개수를 다르게 하여 통신하는 동안 네트워크 전체 패킷의 크기를 구하여, PAC과 PNS사이의 캡슐화 과정이 네트워크 부하에 가장 많은 영향을 주는 요소로 작용한다. 따라서 본 연구에서는 최적의 패킷 당 프레임 수를 산출하기 위해 패킷에 할당 하는 프레임 개수를 증가시켜 통화 품질에 문제가 없는 종 단간 지연을 150ms 이내로 할 때, 패킷 당 프레임 개수는 $2{\sim}3$개가 적합하다는 결론을 얻었다.

이하선 천엽에 발생한 상피-근상피암종의 치험례 (Epithelial-myoepithelial carcinoma on the superficial lobe of the parotid gland: a case report)

  • 진선미;유현호;류석환;신동윤;황희성;김철훈;김복주
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • 제37권6호
    • /
    • pp.505-509
    • /
    • 2011
  • Epithelial-myoepithelial carcinoma (EMC) is a low-grade malignant salivary gland neoplasm that was first described in 1972. EMC occurs in the older age group, there is a female predilection and mainly involves the parotid gland. Most authors recommend superficial parotidectomy as a treatment for low-grade malignant tumor in the superficial lobe of parotid gland. The treatment of epithelial-myoepithelial tumors typically includes surgical excision aimed at achieving a R0 resection. This paper reports a case of EMC of the parotid gland treated only by a conservational surgical excision. The lesion was exposed by the retromandibular approach and detached. After the parotid gland envelop was exposed, the mass was observed and was easy to remove due to capsulation. The preoperative diagnosis was a pleomorphic adenoma on the left parotid gland. The tumor was removed surgically with a conservative extracapsular dissection. The postoperative diagnosis was EMC, so superficial parotidectomy or radiation therapy was considered. Nevertheless, the patient was observed and no additional treatment was attempted because the patient was old and a successfully excision of the tumor had been achieved.

Hydrogenated Lecithin 과 Co-emulsifier를 사용한 Nano-some의 제조 메커니즘과 Kojic Acid 및 Kojic Dipalmitate의 캡슐화 방법 (The Manufacturing Mechanism of Nano-some and Method of Capsulation of Kojic Acid and Kojic Dipalmitate with Hydrogenated Lecithin and Co-emulsifiers)

  • 김인영;제구환;이주동
    • 한국응용과학기술학회지
    • /
    • 제17권4호
    • /
    • pp.248-256
    • /
    • 2000
  • We investigated the property of formation of mono-vesicle(designated nano-some) with using of the combined co-emulsifiers and phospholipid. Nano-some was prepared with hydrogenated lecithin(HL) and diethanolamine cetyl phosphate(DEA-CP) by swelling reaction. Kojic acid and kojic dipalmitate could be made stabilization by nano-some system using microfluidizer(MF). Nano-some has a good affinity to skin by means of this system. The composition was compounded by 2% of hydrogenated lecithin (phosphatidyl choline contained with 75%, 0.5% of DEA-CP and 0.5% of diglyceryl dioleate (DGDO). To make nano-some, several conditions of MF have to be considered as follows. The optimum pH was 6.0. The pressure was 10,000psi and passage temperature was at $306^{\circ}C$. The nano-some base was passed to homogenize continually 3 times through MF. The Particle size distributions of the vesicles were with in $57{\sim}75.7nm$(mean 66nm) by measuring the Zetasizer-3000. Zeta potential of vesicles with 3 times passage through MF was -24.8mV. Formations for nano-some vesicle certificated photograph by scanning electric magnification (SEM). Stability of nano-some was very good for 6months. The turbidity was very good transparency compared nano-some with liposome. It was formed the mono vesicle in the opposite direction to be formed the multi-lamellar vesicle of liposome.

부형제의 혼합비에 따른 분말식초의 품질 특성 (Effects of the Proportions of Wall Materials on the Characteristics of Spray Dried Vinegar)

  • 황성희;홍주헌;정용진;윤광섭
    • 한국식품저장유통학회지
    • /
    • 제9권2호
    • /
    • pp.189-193
    • /
    • 2002
  • 천연식초를 이용하여 분말식초의 제조방법을 개발하고자 부형제의 비율을 달리하여 제조한 분말식초의 품질특성을 평가하여 분말식초의 제조 가능성을 검토하였다. 혼합 피복 물질로 제조된 분말식초의 품질특성을 비교한 결과 $\beta$-cyclodextrin과 gum arabic이 2.5:7.5의 비율로 제조한 분말식초가 비교적 낮은 수분함량을 나타내었고 산도는 높은 수치를 나타내 식초를 포집하는 능력이 가장 좋은 것으로 나타났다. 또한 이 비율로 제조한 분말식초의 흡습성 또한 비교적 낮은 값을 나타내었으며 열안정성은 모든 시료가 높은 수치를 나타내 열에는 모두 안정함을 알 수 있었다. 주사 현미경으로 관찰한 분체의 형태는 모두 구형을 형성하여 분말식초에서 캡슐이 형성되었음을 알 수 있었다. 관능검사 결과도 신맛의 증가로 높은 점수를 받았다. 이상의 결과로 분말식초의 제조시 피복물질의 혼합비율별은 $\beta$-cyclodextrin 과 gum arabic을 2.5:7.5의 비율로 제조하는 것이 가장 우수한 것으로 나타났다.