• Transactions of the Korean hydrogen and new energy society
• /
• v.24 no.1
• /
• pp.20-28
• /
• 2013

Photobiological hydrogen production by nitrogen-fixing unicellular cyanobacteria has long been considered to be an environmentally sound and very promising method for the future supply of renewable clean energy. Using six Korean nitrogen-fixing unicellular cyanobacterial strains and the Synechococcus sp. strain Miami BG043511 we performed cultivation experiments to find out the strain-specific optimal temperature for population growth and $H_2$ production. Under $20^{\circ}C$ the population growth of all the tested strains was significantly retarded in contrasts to the faster and higher growth under 25, 30 or $35^{\circ}C$. The highest growth rates in all the 7 strains were measured under $30^{\circ}C$ while the maximal biomass yields were under $30^{\circ}C$ (strains CB-MAL 026, 054, and 055) or $35^{\circ}C$ (strains 002, 031, 058, and Miami BG043511). The difference between the maximal biomass yields at $30^{\circ}C$ and $35^{\circ}C$ was not greater than 10%. The quantity of photobiologically produced $H_2$ was only slight larger under $35^{\circ}C$ than that under $20^{\circ}C$. Our result may suggest a two-step process of $H_2$ production which includes rapid and sizable production of biomass at $30^{\circ}C$ and the following high $H_2$ production at $20^{\circ}C$ by the test strains of marine nitrogen-fixing unicellular cyanobacteria.

• Entomological Research
• /
• v.48 no.5
• /
• pp.416-428
• /
• 2018

To gain an insight into the function of heat shock proteins (HSPs) in insects during thermal stress, three HSP cDNAs were identified in the transcriptome of adult Heortia vitessoides, one of the most destructive defoliating pests in Aquilaria sinensis (Loureiro) Sprenger forests. The open reading frames of HvHsp60, HvHsp70, and HvHsp90 were 1,719, 2,070, and 2,151 bp in length, respectively, and encoded proteins with molecular weights of 61.05, 75.02, and 82.23 kDa, respectively. Sequence analysis revealed that all three HSPs were highly conserved in structure. Regarding the stage-specific expression profiles, HvHsp60, HvHsp70, and HvHsp90 mRNAs were detected in all developmental stages. Regarding the tissue-specific expression profiles, the expression levels of the three HSP genes were different in various larval and adult tissues. Moreover, the expression patterns of heat-stressed larvae, pupae, and adults indicated that HvHsp60, HvHsp70, and HvHsp90 were heat-inducible. In particular, HvHsp60 transcripts increased dramatically in larvae and pupae that were heat-stressed at $40^{\circ}C$ and were upregulated in adults that were heat-stressed at $35^{\circ}C$ and $40^{\circ}C$. The expression of HvHsp70 significantly increased in all of the three different developmental stages at $35^{\circ}C$, $40^{\circ}C$, and $45^{\circ}C$. The expression of HvHsp90 obviously increased at $30^{\circ}C$, $35^{\circ}C$, and $40^{\circ}C$ in larvae and could be induced at $35^{\circ}C$ in pupae and adults. The results suggest that HSP60, HSP70, and HSP90 play a major role in protecting H. vitessoides against high-temperature stress.

• Journal of Food Hygiene and Safety
• /
• v.27 no.2
• /
• pp.109-116
• /
• 2012

The study indicated that antimicrobial activity about gram positive and gram negative bacteria of ginger-oleoresin(GO) extract with the condition of ethanol and supercritical fluid extractions. As the concentration of extraction increases, the clear zone of GO ethanol extract also increased dependently. This led the antimicrobial activity of gram positive bacteria to take bigger place than gram negative bacteria especially in Listeria monocytogenes. There was a high antimicrobial activity in E-III treatment where the ratio of the ginger powder extract to ethanol extraction was 1:6. It was quite effective to treat the antimicrobial activity of GO ethanol extract under $80^{\circ}C$ and there was not big difference in the intervals which were the extraction time - 1 to 7 hours. The antimicrobial activity of supercritical fluid extract seemed to take the biggest place in Listeria monocytogenes. From the supercritical fluid extract, it was shown the strong ability of antimicrobial activity in the condition with 100 bar $35^{\circ}C$, 250 bar $35^{\circ}C$ and 250 bar $65^{\circ}C$. Furthermore, according to the case of solvent extract, there was not any significant difference in the antimicrobial activity with condition of extraction. However, there was significant antimicrobial activity in E-III treatment of 100 bar and 500 bar of extraction pressure, and $35^{\circ}C$ and $65^{\circ}C$ of extraction temperature.

• Food Science of Animal Resources
• /
• v.32 no.3
• /
• pp.354-363
• /
• 2012

The study was conducted to determine bio-markers and establish shelf-life for eggs and egg products. The selected biomarkers were measured storage period according to samples (two months for table eggs and two weeks for whole liquid eggs) and five storage temperatures ($10^{\circ}C$, $15^{\circ}C$, $25^{\circ}C$, $35^{\circ}C$ and $45^{\circ}C$). The bio-markers for table eggs determined pH, acid value, VBN (volatile basic nitrogen), HU (Haugh unit), aerobic plate counts, coliform group, and Salmonella sp. The bio-markers for whole liquid eggs excluded HU in the bio-markers of eggs. The shelf-life of table eggs observed as 42 d at $10^{\circ}C$, 27 d at $15^{\circ}C$, 9 d at $25^{\circ}C$, 2 d at $35^{\circ}C$, and 1 d at $45^{\circ}C$ in sensory overall acceptability. The shelf-life of pasteurized whole liquid eggs observed as 7 d at $10^{\circ}C$, 3 d at $15^{\circ}C$, 2 d at $25^{\circ}C$, 1 d at $35^{\circ}C$, and less than one d at $45^{\circ}C$ in total plate count. The shelf-life of non- pasteurized whole liquid eggs observed as 4 d at $10^{\circ}C$, 2 d at $15^{\circ}C$, 1 d at $25^{\circ}C$, and less than 1 d at $35^{\circ}C$ and $45^{\circ}C$ in total plate count.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2003.04a
• /
• pp.104.1-104
• /
• 2003

홍화유를 35$^{\circ}C$, 8$0^{\circ}C$ 추출조건 온도에서 각각 1, 3, 6시간 추출하여 HPLC 사용하여 $\alpha$,${\gamma}$,$\delta$-tocopherol 정량하였다. 정량결과 $\alpha$-tocopherol 함량이 ${\gamma}$-tocopherol 함량 보다 높게 나타났으며 $\delta$-tocopherol은 검출되지 않았다 총 tocopherol 함량은 35$^{\circ}C$ 추출조건에서 보다 8$0^{\circ}C$ 추출조건에서 높게 나타났으며 8$0^{\circ}C$ 6시간 추출조건에서 0.23%라는 함량을 나타났다. 또한 반응표면분석에 의하여 홍화유 추출조건에 따른 campesterol, stigmasterol, $\beta$-sitosterol 및 total sterol의 추출 최적화를 모니터링하였으며, 추출온도(35~75$^{\circ}C$, X$_1$), 추출시간(1~11시간, X$_2$), 시료의 전처리 가공 온도(60~10$0^{\circ}C$, X$_3$)를 변수로 한 중심합성계획으로 추출조건을 최적화하였다 추출온도, 추출시간 및 시료의 전처리 가공 온도가 각각 54.69$^{\circ}C$, 4.02시간, 98.37$^{\circ}C$ 이었을 때 campesterol은 0.3852% 추출율을 보였으나 stigmasterol, $\beta$-sitosterol 및 total sterol 반응표면분석 결과 유의차가 없었다. 한편, 추출된 홍화유와 conjugated linoleic acid (CLA)를 1:3 ㏖ 비율로 혼합한 후 고정화효소인 IM60 lipased와 1, 2, 3, 6, 24시간 동안 합성하여 재구성지질을 생성하고 GC에 의해 지방산 조성을 분석한 결과, 총 CLA의 함량은 각각 2.134%, 6.524%, 8.606%, 21.590%, 31.791%로 증가됨을 알 수 있었다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.28 no.10
• /
• pp.615-619
• /
• 2015

In this study, in order to develop the composition ceramics with the excellent electrocaloric properties, 8/65/35 PLZT ceramics were fabricated by the conventional solid-state method with the addition of $Bi_2O_3$, CuO, $Li_2CO_3$ and the variation of sintering temperature from $930^{\circ}C$ to $990^{\circ}C$. The XRD pattern of all specimens indicated general perovskite structure and the rhombohedral phase were observed. Curie temperature ($T_c$) of all specimens was observed in the vicinity of about $190^{\circ}C$. Density, coercive field and remnant polarization of the specimen sintered at $950^{\circ}C$ was $7.55g/cm^3$, 8.895 kV/cm, $11.22{\mu}C/cm^2$, respectively. EC effect of PLZT ceramics was measured by indirect method and the temperature change ${\Delta}T$ due to the electrocaloric effect was calculated by Maxwell's relations. ${\Delta}T$ of ceramic sintered at $950^{\circ}C$ was $0.21^{\circ}C$ under application of 40 kV/cm at $190^{\circ}C$.

• Electrical & Electronic Materials
• /
• v.8 no.5
• /
• pp.594-600
• /
• 1995

Dielectric properties at microwave frequencies of ($Zr_{0.65}$, $Sn_{0.35}$) $Ti_{1.04}$ $O_{4.04}$ ceramics with additives, NiO as an agent to improve dielectric properties and $B_{2}$ $O_{3}$ as a firing agent were investigated. When 0.5 - 1.5 wt% of NiO is add, the grain growth is inhibited and the shape of the grain is uniformed, Dielectric constant(Fr) and bulk density are increased with raising amount of NiO at sintering temperature of 1330 - 1360.deg. C, but the temperature coefficient of resonant frquency(.epsilon.$_{r}$) decreased gradually as the NiO content increased. The value of Qx $f_{o}$ was increased as the amount of NiO was increased in the range of 0.5 to 1.0 wt% and the Qx $f_{o}$, was decreased slightly with raising sintering temperature. With NiO of 1.0 wt% and at sintering temperature of 1360.deg. C, this ceramics was found to have excellent microwave properties of .epsilon.$_{r}$=37.8, Qx $f_{o}$ = 48.600 and .tau.$_{f}$ = 7 ppm/.deg. C.C.. C.. C.C.. C.. C.

• Korean Journal Plant Pathology
• /
• v.10 no.3
• /
• pp.235-239
• /
• 1994

Viral RNA was extracted from purified Chinese cabbage strain of turnip mosaic virus (TuMV-Ca) from infected leaves of turnip. Polyadenylated genomic viral RNA was recovered by oligo (dT) cellulose column chromatography and used as a template for the synthesis of complementary DNA (cDNA). Recombinant plasmids contained cDNA ranged from about 900 bp to 2, 450 bp were synthesized. Among the selected 41 transformants, pTUCA31 and pTUCA35 had over 2 Kbp cDNA insert. Restriction endonuclease patterns of the clones examined were very similar among them. Clones pTUCA23 and pTUCA31 were overlapped with pTUA35. The longest clone pTUCA35, encoding 3'-end, showed that it contained two sites for EcoRI, and one site for BamHI, ClaI, HincII, SacI and XbaI, respectively. The restriction mapping indicated that the clone pTUCA35 contained partial nuclear inclusion body gene, complete coding region of the coat protein and 3' untranslated region of TuMV-Ca genomic RNA.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.35 no.2
• /
• pp.106-110
• /
• 2017

The developmental responses of insects to temperature are important considerations in gaining a better understanding of their ecology and life histories. Temperature dependent models permit examination of the effect of temperature on the geographical distributions, population dynamics, and management of insects. The measurements of insect developmental and survival responses to temperature pose practical challenges that depend. The developmental characteristics of A. diaperinus were investigated at four temperature regimes (20, 25, 30 and $35^{\circ}C$), a relative humidity of 60%, and a light:dark photoperiod of 16:8h. The developmental time from larva to adult was 129.0, 49.8, 40.5 and 31.9 days at temperatures of 20, 25, 30 and $35^{\circ}C$, respectively. Pupal rate was 80.0%, 100%, 83.3% and 91.7% at temperatures of 20, 25, 30 and 35 respectively. There is an increasing need for a standardized manual for rearing this. Pupa had significantly lower weights at $35^{\circ}C$ than at the other temperatures. Female pupae (20mg) were significantly heavier than male (17mg).

• Applied Chemistry for Engineering
• /
• v.10 no.1
• /
• pp.35-40
• /
• 1999

The variations of the glass transition, melting peaks, molecular weight and its distribution (polydispersity index: PI) due to the annealing temperature and time have been investigated using the thermoplastic segmented polyurethanes (TPUs) and its blends based on the contents of hard segment. The position of the melting peak and its magnitude have been increased with the annealing temperature and time. This may be arised from the rearrangement of the microdomain structure due to the long-range or short-range segmental motion, the order-disorder transition of non-crystalline microphase, the variation of the domain size or the degree of disorder of crystalline structure by given different thermal histories. The annealing temperature and time affected the molecular weights and polydispersity : the number and weight average molecular weights were increased, while the polydispersity index (PI) deceased at certain temperatures : for TPU-35 at $135^{\circ}C$, for TPU-44 at $170^{\circ}C$ and for TPU-53 at $180^{\circ}C$. The temperatures which give the variations in molecular weights and in PIs are consistent with the annealing temperatures of which $T_3$ solely exists for each sample. Thus it is suggested that the chain dissosiation and recombination simultaneously occur at the above mentioned temperature for each sample.