• Korean journal of applied entomology
• /
• v.61 no.1
• /
• pp.165-172
• /
• 2022

Insects have evolved successfully by adapting to their environments through development and reproduction. Temperature-dependent models have been used to calculate the intrinsic optimal, optimal development, and optimal fecundity temperatures of insects and mites; for this study, we reviewed 112 works that focused on these parameters. The insects and mites investigated in this study include 14 Acari, 8 Coleoptera, 5 Diptera, 31 Hemiptera, 7 Hymenoptera, 18 Lepidoptera, 1 Orthoptera, 5 Psocoptera, and 5 Thysanoptera species. The results of this study showed that the interval distance between the intrinsic optimal and optimal fecundity temperatures was smaller than that between the intrinsic optimal and optimal development temperatures of the all insects and mites investigated except for those in the order Thysanoptera. We found that there is a close relationship between the intrinsic optimal and optimal fecundity temperatures.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.381.1-381.1
• /
• 2014

In this study, we investigated the deposition behavior and the etch resistivity of plasma polymerized carbon hardmask (ppCHM) film with the variation of process temperature. The etch resistivity of deposited ppCHM film was analyzed by thickness measurement before and after direct contact reactive ion etching process. The physical and chemical properties of films were characterized on the Fourier transform infrared (FT-IR) spectroscope, Raman spectroscope, stress gauge, and ellipsometry. The deposition behavior of ppCHM process with the variation of temperature was correlated refractive index (n), extinction coefficient (k), intrinsic stress (MPa), and deposition rate (A/s) with the hydrocarbon concentration, graphite (G) and disordered (D) peak by analyzing the Raman and FT-IR spectrum. From this experiment we knew an optimal deposition condition for structure of carbon hardmask with the higher etch selectivity to oxide. It was shown the density of ppCHM film had 1.6~1.9 g/cm3 and its refractive index was 1.8~1.9 at process temperature, $300{\sim}600^{\circ}C$. The etch selectivity of ppCHM film was shown about 1:4~1:8 to undoped siliconoxide (USG) film (etch rate, 1300 A/min).

• The Korean Journal of Applied Statistics
• /
• v.17 no.2
• /
• pp.281-301
• /
• 2004

In this paper we consider the change point problem in a sequence of univariate normal observations. We want to know whether there is any change point or not. In case a change point exists, we will identify its change type. Namely, it can be a mean change, a variance change, or both the mean and variance change. The intrinsic Bayes factors of Berger and Pericchi (1996, 1998) are used to find the type of optimal change model. The Gibbs sampling including the Metropolis-Hastings algorithm is used to estimate all the parameters in the change model. These methods are checked via simulation and applied to the winter average temperature data in Seoul.

• The Korean Journal of Pesticide Science
• /
• v.9 no.3
• /
• pp.221-230
• /
• 2005

Temperature is an important ambient factor affecting the physiology and metabolism of aquatic invertebrates. In this study, we studied about the survival, reproduction and growth effects of 4 different temperatures(16, 20, 24, $28^{\circ}C$) in four Korean cladoceran, Daphnia sp., Daphnia obtusa, Moina macrocopa, Simocephalus vetulus and Daphnia magna as an international standard species. All 5 water flea tested showed that molting time, fecundity and intrinsic rate of natural increase(r) in high temperature condition were higher than those in lower temperature. On the other hand, lower survivals and longer time to start of offspring were showed in high temperature. Our results suggest that the optimal temperatures of Daphnia sp.,, Moina macrocopa and Simocephalus vetulus seem to be about $20^{\circ}C$ except for Daphnia obtusa which as showed good survivals and reproductions in $16^{\circ}C$.

• Transactions on Electrical and Electronic Materials
• /
• v.10 no.3
• /
• pp.75-79
• /
• 2009

An intrinsic silicon thin film passivation layer is deposited by the microwave remote-plasma enhanced chemical vapor deposition at temperature of $175^{\circ}C$ and various gas ratios for solar cell applications. The good quality amorphous silicon films were formed at silane $(SiH_4)$ gas flow rates above 15 seem. The highest effective carrier lifetime was obtained at the $SiH_4$, flow rate of 20 seem and the value was about 3 times higher compared with the bulk lifetime of 5.6 ${\mu}s$ at a fixed injection level of ${\Delta}n\;=\;5{\times}10^{14}\;cm^{-3}$. An annealing treatment was performed and the carrier life times were increased approximately 5 times compared with the bulk lifetime. The optimal annealing temperature and time were obtained at 250 $^{\circ}C$ and 60 sec respectively. This indicates that the combination of the deposition of an amorphous thin film at a low temperature and the annealing treatment contributes to the excellent surface and bulk passivation.

• BMB Reports
• /
• v.42 no.5
• /
• pp.293-298
• /
• 2009

Temperate mycobacteriophage L1 encodes an unusual repressor (CI) for regulating its lytic-lysogenic switching and, in contrast to the repressors of most temperate phages, it binds to multiple asymmetric operator DNAs. Here, ions like $Na^+$, $Cl^-$, and $acetate^-$ ions were demonstrated to facilitate the optimal binding of CI to cognate operator DNA, whereas $K^+$, $Li^+$, ${NH_4}^+$, $Mg^{2+}$, $carbonate^{2-}$, and $citrate^{3-}$ ions significantly affected its operator binding activity. Of these ions, $Mg^{2+}$ unfolded CI most severely at room temperature and, compared to $Mg^{2+}$, $Na^+$ provided improved thermal stability to CI. Furthermore, the intrinsic tryptophan fluorescence of CI was changed notably upon replacing $Na^+$ with $Mg^{2+}$ and these opposing effects of $Mg^{2+}$ and $Na^+$ were also noticed in their actions on the C-terminal fragment (CTD) of CI. Taken together, $Na^+$ appeared to be more appropriate than $Mg^{2+}$ for maintaining the biologically active conformation of CI needed for its optimal binding to operator DNA.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.10 no.6
• /
• pp.494-499
• /
• 2005

The chemical, physical, and emulsifying properties of BSF-1, which is an extracellular lipopolysaccharide biosurfactant produced by Klebsiella oxytoca strain BSF-1, were studied. BSF-1 was found to be composed mainly of carbohydrate and fatty acids. The average molecular weight was $1,700{\sim}2,000 kDa$. The polysaccharide fraction contained L-rhamnose, D-galactose, D-glucose, and D-glucuronic acid at a molar ratio of 3:1: 1:1. The fatty acid content was 1.1 % (w/w) and consisted mainly of palmitic acid (C16:0), 3-hydroxylauric acid (3-OH-C12:0), and lauric acid (C12:0). In terms of thermal properties, BSF-1 was revealed to have inter- and intra-molecular hydrogen bonds. The hydrodynamic volume (intrinsic viscosity) of BSF-1 was 22.8dL/g. BSF-1 could be maintained as a stable emulsion for 48 h through a low-level reduction in surface tension. The optimal emulsification temperature was $30^{\circ}C$. Emulsification by BSF-1 was efficient at both acidic and neutral pH values.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.29 no.6
• /
• pp.843-848
• /
• 1996

As the first step of studies related to production of chitooligosaccharides by physical methods, chitosan solution were sonicated with 20 kHz and various treatment effects were examined to present fundamental data of sonicated chitosan solution. Intrinsic viscosity of chitosan solution sharply decreased from 3.76 dl/g to 2.90 dl/g until 5 minutes of sonication and then slowly decreased. With low volume of chitosan solution, sonication was very effective and temperature of chitosan solution slightly affected the efficiency of sonication. In case of changing the solvent, no significant differences were observed on the effect of sonication, however, acetate buffer had highest sonication effect among various solvents. The sonication effect was increased as the increasement of the value of pH, on the contrary, ionic strength and type of counterions showed no effect on sonication. With these results, we assumed that optimal sonication treatment would be as follows, solution volume was $10\~20\;ml$, temperature range was $20\~30^{\circ}C$, pH value of solution was 4.5 and type of solvent was acetate buffer.

• Microbiology and Biotechnology Letters
• /
• v.17 no.5
• /
• pp.421-428
• /
• 1989

A soil bacterium synthesizing an extremely viscous biopolymer was isolated and identified as Pseudomonas delafieldii. The optimal pH and temperature for the growth were 6.5 and 3$0^{\circ}C$, respectively. Maximum specific growth rate was 0.24 h$^{-1}$. The specific polysaccharide productivity, growth yield and product yield were 6.25 mg/g-cell/h, 54.5% and 38.39%, respectively. The polysaccharide was presumed to be $\beta$-glucan containing glucose and gluconolactone (1.9：1.0 in molar ratio) and 1.35 % acetyl group, Element analysis showed that it contained carbon (31.85%) and hydrogen (5.15%). The weight average molecular weight by GPC was 5.64$\times$10$^7$. The intrinsic viscosity was 42.84 dl/g.

• Transactions of Materials Processing
• /
• v.21 no.4
• /
• pp.240-245
• /
• 2012

With the increasing demand for light-weight materials to reduce fuel consumption, the automobile industry has extensively studied magnesium alloys which are light weight metals. The intrinsic poor formability and poor ductility at ambient temperature due to the hexagonal close-packed (HCP) crystal structure and the associated insufficient number of independent slip systems restricts the practical usage of these alloys. Hot working of magnesium alloys using a forging or extrusion enables net-shape manufacturing with enhanced formability and ductility since there are several operative non-basal slip systems in addition to basal slip plane, which increases the workability. In this research, the thermomechanical properties of AZ80 Mg alloy were obtained by compression testing at the various temperatures and strain rates. Optical microscopy and EBSD were used to study the microstructural behavior such as misorientation distribution and dynamic recrystallization. The results were correlated to the hardening and the softening of the alloy. The experimental data in conjunction with a physical explanation provide the optimal conditions for net-shape forging under hot or warm temperatures through control of the grain refinement and the working conditions.