• 제목/요약/키워드: octadecane

검색결과 45건 처리시간 0.018초

Analysis of Lipophilic Constituents Related to Heartwood Formation in Young Swietenia mahagoni (L.) Jacq Trees

  • Rizki ARISANDI;Koetsu TAKAHASHI;Arif NIRSATMANTO;Sri SUNARTI;Anto RIMBAWANTO;Asri Insiana PUTRI;Noor Khomsah KARTIKAWATI;Liliek HARYJANTO;Toni HERAWAN;Fajar LESTARI;Ganis LUKMANDARU
    • Journal of the Korean Wood Science and Technology
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    • 제52권1호
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    • pp.13-30
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    • 2024
  • Swietenia mahagoni is one of the commercial timbers in Indonesia. Mahogany heartwood is an important characteristic as it relates to the natural durability and aesthetics of the wood. Lipophilic extractives are known to be involved in the heartwood formation process. Therefore, this study aims to determine the lipophilic compounds associated with heartwood formation. The n-hexane extract from sapwood and heartwood samples (1 to 5 years) was analyzed by gas chromatography-mass spectrometry. The results showed that the content of n-hexane extract ranged from 0.76% to 2.45% based on dry wood. The main group of compounds identified in the lipophilic fraction consisted of sterols (β-sitosterol, stigmasterol, campasterol, and cyclolaudenol), fatty acids (palmitic, oleic, linoleic, and stearic acid), and hydrocarbons (pentadecane, 1-octadecane, hexadecane, cyclotetracosane, cycloeicosane, and cyclooctacosane) after heartwood formation. In addition, the hydrocarbon fraction was the largest, followed by sterols, fatty acids, and 1-heneicosanol. In the radial variation, the distribution of fatty acids was greater in the sapwood than in the heartwood (4-year-old). However, the reverse pattern was found at the age of 5 years. The lipophilic fraction was generally more abundant in the heartwood compared to the sapwood, especially at 5 years of age, with much higher levels than when the heartwood was forming (4 years). These findings show that when the heartwood formation begins, the lipid composition was not fully metabolized at the beginning of heartwood formation compared to 5-year-old trees.

Synthesis and Characterization of C-meso and C-racemic Isomers of a Reinforced Tetraaza Macrocycle and Their Copper(II) Complexes

  • Jeong, Gyeong Rok;Kim, Juyoung;Kang, Shin-Geol;Jeong, Jong Hwa
    • Bulletin of the Korean Chemical Society
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    • 제35권7호
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    • pp.2043-2048
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    • 2014
  • Two isomers of a new tetraaza macrotricycle 2,2,4,9,9,11-hexaazamethyl-1,5,8,12-tetraazatricyclo[$10.2.2^{5.8}$]-octadecane ($L^2$) containing additional N-$CH_2CH_2$-N linkages, C-meso-$L^2$ and C-racemic-$L^2$, have been prepared by the reaction of 1-bromo-2-chloroethane with C-meso-$L^1$ or C-racemic-$L^1$ ($L^1$ = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane). Both C-meso-$L^2$ and C-racemic-$L^2$ react with copper(II) ion to form $[Cu(C-meso-L^2)]^{2+}$ or $[Cu(C-racemic-L^2)]^{2+}$ in dehydrated ethanol, but do not with nickel(II) ion under similar conditions. Crystal structure of [Cu(C-racemic-$L^2$)($H_2O$)]$(ClO_4)_2$ shows that the complex has distorted square-pyramidal coordination geometry with an apically coordinated water molecule. Unexpectedly, the Cu-N distances [2.016(3)-2.030(3) ${\AA}$] of [Cu(C-racemic-$L^2$)($H_2O$)]$(ClO_4)_2$ are longer than those [1.992(3)-2.000(3) ${\AA}$] of [Cu(C-racemic-$L^1$)($H_2O$)]$(ClO_4)_2$. As a result, $[Cu(C-racemic-L^2)(H_2O)]^{2+}$ exhibits weaker ligand field strength than $[Cu(C-racemic-L^1)(H_2O)]^{2+}$. The copper(II) complexes readily react with CN- ion to yield the cyano-bridged dinuclear complex $[Cu_2(C-meso-L^2)_2CN]^{3+}$ or $[Cu_2(C-racemic-L^2)_2CN]^{3+}$. Spectra and chemical properties of $[Cu(C-meso-L^2)]^{2+}$ and $[Cu_2(C-meso-L^2)_2CN]^{3+}$ are not quite different from those of $[Cu(C-racemic-L^2)]^{2+}$ and $[Cu_2(C-racemic-L^2)_2CN]^{3+}$, respectively.

거대세고리와 거대네고리 리간드의 니켈 (II) 및 구리 (II) 착물의 합성과 니켈 (II) 착물의 평면사각형-팔면체 평형 (Macrotri-and Macrotera-cyclic Ni (II) and Cu (II) Complexes. Synthesis of the Complexes and the Square Planar-Octahedral Equilibrium of the Ni (II) Complexes)

  • 강신걸;정수경
    • 대한화학회지
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    • 제35권5호
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    • pp.527-533
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    • 1991
  • 포름알데히드, 테트라아민류 및 디아민류의 Ni(II) 또는 Cu(II) 이온 존재하에서의 주형축합반응으로부터 헥사아자 거대세고리 및 거대네고리 리간드의 평형사각형 착물 $[M(L)]^{2+}$(M = Ni(II) 또는 Cu(II); L = 4-메틸-1,3,6,8,11,14-헥사아자트리시클로[12,2,1,$1^{8,11}$]옥타데칸(C), 1,3,10,12,15,18-헥사아자테트라시클로[6,2,1,$1^{12,15},0^{4,9}]$도코산(D), 4-메틸-1,3,6,8,12,15-헥사아자트리시클로[13,3,1,$1^{8,12}$]에이코산(F) 또는 1,3,10,12,16,19-헥사아자테트라시클로[l7,3,1,$1^{12,16},0^{4,9}]$테트라코산(G))를 합성하였다. 이들 착물의 여섯 원자 킬레이트고리에는 두개 씩의 1,3-디아자시클로펜탄 도는 1,3-디아자시클로헥산 고리가 있다. C와 F의 착물의 다섯원자 킬레이트고리에는 메틸기가 그리고 D와 G의 경우에는 시클로헥산 고리가 있다. 이들 니켈(Ⅱ) 및 구리(Ⅱ) 착물의 합성과 특성, 그리고 수용액에서의 $[Ni(L)]^{2+}+2H_2O{\rightleftharpoons}[Ni(L)(H_2O)_2]^{2+}$의 평형에 미치는 리간드 구조의 영향이 논의 된다.

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품종별 곶감(Diospyros kaki)의 영양성분 분석, 산화방지 효과 및 뇌 신경세포 보호효과 (Nutritional composition, antioxidant capacity, and brain neuronal cell protective effect of cultivars of dried persimmon (Diospyros kaki))

  • 김종민;박선경;강진용;박상현;박수빈;유슬기;한혜주;이수광;이욱;허호진
    • 한국식품과학회지
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    • 제50권2호
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    • pp.225-237
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    • 2018
  • 본 연구에서는 떫은감의 5가지 공시품종인 상주둥시, 고종시, 고동시, 갑주백목, 청도반시를 이용하여 가공된 곶감의 유리당, 지방산, 무기성분, 구성 아미노산, 바이타민 C와 같은 영양성분 분석을 진행하였고, 총 페놀성 화합물의 함량을 측정함과 동시에 in vitro 상에서 ABTS, DPPH 라디칼 제거 활성을 측정하였고, FRAP, 지방질과산화물 생성 억제효과, 아세틸콜린 분해효소 억제효과를 확인하였다. 이를 토대로 MC-IXC 뇌 신경세포에서 신경세포 생존율과 산화적 스트레스 억제효과, 세포막 보호효과를 확인하였다. 유리당 분석에서는 상주둥시 품종이 포도당(glucose), 과당(fructose) 함량이 가장 높았고, 지방산 함량은 상주둥시 품종에서는 올레산(oleic acid)이, 고동시, 고종시, 갑주백목, 반시에서는 팔미트산(palmitic acid)이 가장 높은 비율을 나타내었다. 포타슘과 인의 함량이 다른 무기성분들에 비해 월등히 높았으며, 주요 아미노산으로는 아스파트산(aspartic acid)과 글루탐산(glutamic acid)이 상대적으로 높았고, 바이타민 C 역시 5 품종 모두 검출되었다. 또한, 총 페놀성 화합물을 상주둥시의 95% 에탄올 추출물이 가장 높았고, ABTS, DPPH 라디칼 제거 활성과 FRAP, 지방질 과산화물 생성 억제활성 그리고 아세틸콜린 분해효소 억제 활성에서 갑주백목의 80% 에탄올 추출물이 가장 높은 활성을 나타내었다. 산화적 스트레스에 대한 뇌 신경세포 생존율은 갑주백목이 가장 높은 생존율을 나타내었으며, 산화적 스트레스 생성 억제와 뇌 신경세포 세포막 보호효과 역시 갑주백목이 가장 큰 억제 활성과 보호효과를 보였다. 이와 같은 결과로 보아 곶감은 뛰어난 산화방지 효과를 가지고 있으며, 이를 근간으로 뇌 신경세포 보호효과도 우수한 것으로 나타났다. 이러한 생리활성능력은 임산물의 고부가가치 소재개발에 있어 산업적 활용 가능성을 재고하는데 도움이 될 것으로 판단된다. 다만 생리활성 물질의 검증이 부족하고, 산화방지 활성이 in vitro 상의 효과에 국한된 점에서 향후 물질분석과 인기지능 개선 효과 검증을 통해 인기지능 개선 건강기능식품 소재로서 연구될 수 있을 것으로 판단된다.

설비공학 분야의 최근 연구 동향 : 2013년 학회지 논문에 대한 종합적 고찰 (Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2013)

  • 이대영;김사량;김현정;김동선;박준석;임병찬
    • 설비공학논문집
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    • 제26권12호
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    • pp.605-619
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    • 2014
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2013. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and relative parts including orifices, dampers and ducts, fuel cells and power plants, cooling and air-conditioning, heat and mass transfer, two phase flow, and the flow around buildings and structures. Research issues dealing with home appliances, flows around buildings, nuclear power plant, and manufacturing processes are newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for general analytical model for desiccant wheels, the effects of water absorption on the thermal conductivity of insulation materials, thermal properties of Octadecane/xGnP shape-stabilized phase change materials and $CO_2$ and $CO_2$-Hydrate mixture, effect of ground source heat pump system, the heat flux meter location for the performance test of a refrigerator vacuum insulation panel, a parallel flow evaporator for a heat pump dryer, the condensation risk assessment of vacuum multi-layer glass and triple glass, optimization of a forced convection type PCM refrigeration module, surface temperature sensor using fluorescent nanoporous thin film. In the area of pool boiling and condensing heat transfer, researches on ammonia inside horizontal smooth small tube, R1234yf on various enhanced surfaces, HFC32/HFC152a on a plain surface, spray cooling up to critical heat flux on a low-fin enhanced surface were actively carried out. In the area of industrial heat exchangers, researches on a fin tube type adsorber, the mass-transfer kinetics of a fin-tube-type adsorption bed, fin-and-tube heat exchangers having sine wave fins and oval tubes, louvered fin heat exchanger were performed. (3) In the field of refrigeration, studies are categorized into three groups namely refrigeration cycle, refrigerant and modeling and control. In the category of refrigeration cycle, studies were focused on the enhancement or optimization of experimental or commercial systems including a R410a VRF(Various Refrigerant Flow) heat pump, a R134a 2-stage screw heat pump and a R134a double-heat source automotive air-conditioner system. In the category of refrigerant, studies were carried out for the application of alternative refrigerants or refrigeration technologies including $CO_2$ water heaters, a R1234yf automotive air-conditioner, a R436b water cooler and a thermoelectric refrigerator. In the category of modeling and control, theoretical and experimental studies were carried out to predict the performance of various thermal and control systems including the long-term energy analysis of a geo-thermal heat pump system coupled to cast-in-place energy piles, the dynamic simulation of a water heater-coupled hybrid heat pump and the numerical simulation of an integral optimum regulating controller for a system heat pump. (4) In building mechanical system research fields, twenty one studies were conducted to achieve effective design of the mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, and renewable energies in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment is mostly focused on indoor environment and building energy. The main researches of indoor environment are related to infiltration, ventilation, leak flow and airtightness performance in residential building. The subjects of building energy are worked on energy saving, operation method and optimum operation of building energy systems. The remained studies are related to the special facility such as cleanroom, internet data center and biosafety laboratory. water supply and drain system, defining standard input variables of BIM (Building Information Modeling) for facility management system, estimating capability and providing operation guidelines of subway station as shelter for refuge and evaluation of pollutant emissions from furniture-like products.