The present study was conducted to investigate the effect of environmental temperature and backfat thickness (BT) on the reproductive performance of lactating sows. Sixty crossbred sows were allotted to four groups in a 2×2 factorial arrangement by environmental temperature (high temperature [HT], 27.5±1.76℃; low temperature [LT], 23.3±0.89℃) and BT (<20 mm, average 17.70 mm; ≥20 mm, average 23.20 mm) from July to August 2019. Sows in the HT group experienced a greater change in BT and a lower feed intake. Losses in body weight and BT were lower in sows with <20 mm BT than in those with ≥20 mm BT. Sows with low BT had a lower weaning-to-estrus interval than sows with high BT (5.20, 4.93 d vs. 5.87, 5.60 d, respectively). Piglet survivability was lower in the HT group (90.31%) than in the LT group (94.87%). Piglet weaning weight and average daily weight gain were greater in sows with <20 mm BT (5.75 kg and 201.46 g, respectively) than in those with ≥20 mm BT (5.49 kg and 188.41 g, respectively). Sows in the HT group had higher cortisol concentrations than those in the LT group (post-farrowing: HT 7.86 μg/mL vs. LT 6.04 μg/mL; weanling: HT 5.48 μg/mL vs. LT 4.40 μg/mL). In conclusion, environmental temperature adversely influenced sow performance and cortisol levels. Moreover, sows with low BT had a greater weaning-to-estrus interval when subjected to heat stress.

In the present study, the effects of extracts from Korean plants on the DNA damage response in HaCaT cells exposed to ultraviolet B (UVB) were investigated. The activity of cells treated for 24 hr with ethanol extracts from Vaccinium spp. (VS), and Vitis vinifera L (VV) alone was similar to that of the non-treated control, but gradually decreased at concentrations above 200μg/mL. However, when post-incubation of UVB-exposed cells was carried out for 24 hr in medium containing VS or VV extracts, the cell activity increased in a concentration-dependent manner compared with that in the normal growth medium. The cell viability of UVB-exposed cells also increased when post-incubated in medium containing VS or VV extracts, in a concentration-dependent manner. Nuclear fragmentation analysis showed that post-incubation with VS or VV extracts decreased the UVB-induced apoptosis by about 10 and 13%, respectively, of that in cells post-incubated in growth medium. After 24 hr of post-incubation in medium containing VS or VV extracts, the level of CPD and 8-OHdG decreased in time- and concentration-dependent manners. Overall these results suggest that VS and VV extracts assist the survival of UVB-exposed cells, in accordance with the respective decrease in the levels of UVB-induced DNA damage.

The structure of nitrogen adsorption complex of fully dehydrated Cd2+ ion exchanged zeolite-X, |Cd46(N)18|[Si100Al92O384], was determined in the cubic space group Fd3 at 21(1) ℃ [a = 24.863(4) ] by single crystal X-ray diffraction analysis. The crystal was prepared by ion exchange in a flowing steam of 0.05 M aqueous solution Cd(NO3)2 : Cd(O2CCH3)2 = 1:1 for five days, followed by dehydration at 500℃ and 2×10-6 Tor. for two days, and exposured to 100 Tor. zeolitically dry nitrogen gas at 21(1) ℃. The structure was determined in atmosphere, and was refined within F0 〉 4Σ(F0) using reflection for which the final error can appear in indices R1 = 0.097 and wR2 = 0.150. In this structure, Cd2+ ions occupied four crystallographic sites. Nine Cd2+ ions filled the octahedral site I at the centers of hexagonal prisms (Cd-O = 2.452(16) a). Eight Cd2+ ions filled site I' (Cd-O = 2.324(19) a). The remaining 29 Cd2+ ions are found at two nonequivalent sites II (in the supercages) with occupancy of 11 and 18 ions. Each of these Cd2+ ions coordinated to three framework oxygens, either at 2.159(15) or 2.147(14) a, respectively. Eighteen nitrogen molecules were adsorbed per unit cell and three per supercage.

Core-shell polymers of methyl methacrylate-styrene system were prepared by sequential emulsion polymerization in the presence of sodium dodecyl benzene sulfonate(SDBS) as an emulsifier using ammonium persulfate(APS) in an initiator and the characteristics of these core-shell polymers were evaluated. Core-shell composite latex has the both properties of core and shell components in a particle, whereas polymer blends or copolymers show a combined physical properties of two homopolymers. This unique behavior of core-shell composite latex can be used in various industrial fields. However, in preparation of core-shell composite latex, several unexpected matters are observed, for examples, particle coagulation, low degree of polymerization, and formation of new particles during shell polymerization. To solve this matters, we study the effects of surfactant concentrations, initiator concentrations, and reaction temperature on the core-shell structure of PMMA-PSt and PSt-PMMA. Particle size and particles distribution were measured by using particle size analyzer, and the morphology of the core-shell composite latex was observed by using transmission electron microscope. Glass temperature was also measured by using differential scanning calorimeter. To identify the core-shell structure, pH of the composite latex solutions was measured.

The structure of a carbon monoxide sorption complex of dehydrated fully Ca2+-exchanged zeolite X, |Ca46(CO)27|[Si100Al92O384]-FAU, has been determined in the cubic space group Fd 3 at 21℃ (a = 24.970(4) ) by single-crystal X-ray diffraction techniques. The crystal was prepared by ion exchange in a flowing stream of 0.05 M aqueous Ca(NO3)2 for three days, followed by dehydration at 400℃ and 2×10-6 Torr for two days, and exposure to 100 Torr of zeolitically dry carbon monoxide gas at 21℃. The structure was determined in this atmosphere and was refined, using the 356 reflections for which Fo 〉 4Σ(Fo), to the final error indices R1 = 0.059 and wR2 = 0.087. In this structure, Ca2+ ions occupy three crystallographic sites. Sixteen Ca2+ ions fill the octahedral site I at the centers of hexagonal prisms (Ca-O = 2.415(7) a). The remaining 30 Ca2+ ions are found at two nonequivalent sites II (in the supercages) with occupancies of 3 and 27 ions. Each of these Ca2+ ions coordinates to three framework oxygens, either at 2.276(10) or 2.298(8) a, respectively. Twenty-seven carbon monoxide molecules have been sorbed per unit cell, three per supercage. Each coordinates to one of the latter 16 site-II Ca2+ ions: C-Ca = 2.72(8) a. The imprecisely determined N-C bond length, 1.26(14) a, differs insignificantly from that in carbon monoxide(g), 1.13 a.

LPCVD(Low Pressure Chemical Vapor Deposition) System을 이용하여 여러가지 증착 변수에 따른 실리콘 박막의 표면형상에 대해 고찰하였다. 중착압력, 중착온도, 반응기체의 유속에 따라 증착층의 표면형상이 큰 변화를 나타냈으며, 증착압력과 반응기체의 유속이 증가할수록 유효면적이 최대가 되는 증착온도가 증가하였다. 이러한 실험결과는 안정한 핵의 생성률이 최대가 될때 유효표면적이 최대가 된다는 가정으로부터 유도된 식과 일치하는 결과를 나타냈다.

This work is to study the variations of adsorption characteristics of binary vapor according to packing system of double-layer bed by fixed bed experiment. Breakthrough curves of single and binary vapor composed of acetone and benzene on single-layer and double-layer adsorption bed composed of activated carbon (AC) and silica-aluminar (SA) were compared. Adsorptions of binary vapor on double-layer bed were influenced by the differences of surface area between adsorbents as well as the polarity difference between adsorbent and adsorbate. The roll-up phenomenon of acetone vapor was happened by replacement with competing adsorption between acetone vapor and benzene vapor on AC bed, but it was not happened on SA bed because acetone vapor and benzene vapor had less difference in affinity with SA bed. The breakthrough times of acetone vapor and benzene vapor on AC/SA double-layer bed were three times and 1.4 times larger respectively than on SA/AC double-layer bed, the differences of breakthrough times were relatively larger than the equilibrium adsorption capacities according to packing system of double-layer bed.

An experimental study on the preparation of monolithic porous polymers by environmentally friend process in supercritical carbon dioxide has been carried out. Polymerization mixture composed of a cross-linking monomer, initiator and functional co-polymer was charged in the reactor with sapphire window. After the system was purged with a flow of CO2 for 15 min, the reactor was pressurized with liquid CO2 up to 100 bars. The reactor was isolated from and placed back to the system via quick connector for shaking until the mixture had become fully homogeneous. The reactor was then heated and pressurized to the required reaction conditions and left overnight. After cooling and CO2 evacuation, the polymer was removed from the reactor as dry, white, continuous monoliths. The effect of experimental conditions on the physical properties of porous polymer was systematically examined, and it was found that monomer content had a major effect on the physical properties of the polymers.

For the purpose of development of a liquid membrane permeator which separates metal ions from aqueous solutions continuously and effectively, a continuous membrane permeator with the membrane solution trapped between extraction and stripping phases by two micro-porous hydrophilic films was manufactured. Experimental researches on the separation of zinc ion from aqueous solutions were performed in the liquid membrane permeator with 30 vol % D2EHPA solution in kerosine as liquid membrane. As results, the liquid membrane permeator separates zinc ion from aqueous solutions continuously and effectively in the wide range of operating conditions. A simple mass transfer rate model using equilibrium constant of the extraction reaction for the system used were proposed, and the model was compared with experimental results of separation of zinc ion in the permeator. And the effects of operating factors, such as space time, pH of extraction solution, extraction temperature, on the separation rate of zinc ion in the permeator were experimentally examined.

An experimental research was preformed for the development of an effective process for zinc oxide waste(zinc ash) reuse. Zinc was selectively leached from zinc ash by 30 vol.% D_2EHPA in kerosine solution, and the leaching velocity was quite fast. Zinc leached was stripped by sulfuric acid solutions, and the amount of zinc stripped was linearly increased with the amount of sulfuric acid used. Zinc oxide fine particles were obtained by dropwise adding of sodium hydroxide solution to the resultant aqueous zinc solution at 85℃.