• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.10 no.6
• /
• pp.666-673
• /
• 1998

Solubilities (LiBr+$CaC1_2$) in water were measured at temperatures form 267.51 to 306.17K for $CaC1_2$ (LiBr+$CaC1_2$)=0.24 by mole. Experimental data were correlated with polynomial equations. Average absolute deviations between the measured and calculated values were 0.31% at concentration smaller than 60wt% and 0.41% at concentration larger than 60wt%, respectively. Vapor pressures were measured at temperatures from 296.75 to 436.75K and concentrations from 40 to 70wt%. Vapor pressure data were fitted to a Antoine-type equation and average absolute deviation was 2.98%. The P-T-X chart and H-T-X chart of $H_2O$/(LiBr+$CaC1_2$) system were constructed by using the correlation equations of solubility, vaper pressure, and heat capacity. The P-T-X chart indicates that $H_2O$/(LiBr+$CaC1_2$) system has potential as a possible working fluid for air-cooled absorption chillers.

• Applied Chemistry for Engineering
• /
• v.9 no.4
• /
• pp.561-564
• /
• 1998

The radial distribution functions of a linear spheroidal type gas molecule $C_2H_4$ were calculated by using the Stockmayer molecular molel, which assumed the $C_2H_4$ molecule as simple quadrupolar molecule. To examine the validity of the calculated radial distribution of $C_2H_4$ gas, the density dependent pressures of $C_2H_4$ gas at several temperatures were calculated and compared with literarily known experimental pressure data of $C_2H_4$ gas. The temperatures examined was 50, 100 and $150^{\circ}C$ and the densities were up to $0.02/{\AA}^3$ (maximum pressure = 1500 atm). The radial distribution function expression used was derived by Yoon, Hacura, and Baglin (YHB) with Baker and Henderson's perturbation theory. The calculated results by a computer showed that the $C_2H_4$ pressures calculated agreed well with the experimental values within ${\pm}5%$ of error range. This indicated that the YHB radial distribution function expression is good enough to obtain various physical quantities sensitive to density such as pressure with resonable accuracy.

• Journal of Sericultural and Entomological Science
• /
• v.17 no.2
• /
• pp.161-170
• /
• 1975

This study is to investigate the content of crude protein intruded in the sericin of cocoon shell and pupa by treatment of buffer solution (pH 1 to pH 13) 20 ml per 1 gram for 30 and 60 minutes at 30$^{\circ}C$, 60$^{\circ}C$ and 100${\pm}$2$^{\circ}C$, respectively. The results obtained are summarized as follows. 1. The quantity of total crude protein obtained from cocoon shell and pupa by treatment during 30 minutes at 30$^{\circ}C$ was dissolved as the largest quantity of 11.874 mg/g at pH 1 and l5.93mg/g at pH 13, but dissolved the smallest quantity 1.75g/g at pH 5 as known. and tile quantity of crude protein treated for 60 minutes is 13.437mg/g at pH 1 and 22.50mg/g at pH 13. Also, the smallest quantity is 2. 813mg/g at pH 5 as known. 2. By the treatment during 30 minutes at 60$^{\circ}C$, the dissolved largest quantity was 13.12mg/g at pH 1 and 21.875 mg/g at pH 13, but the smallest quantity is 2.375mg/g at pH 5 as known After treatment for 60 minutes at 60$^{\circ}C$, the dissolved largest quantity was 17.500 mg/g at pH 1 and 31.56mg/g at pH 13, bu the smallest quantity is 3.849 mg/g at pH 5. 3. The dissolved crude protein from the cocoon shell and pupa by treatment for 30 minutes at 100${\pm}$2$^{\circ}C$ was the largest quantity of 147.000mg/g at pH 1 and 398. 125mg/g at pH 13, but the smallest quantity is 75.00mg/g at pH 5 as known. After treatment for 60 minutes at 100${\pm}$2$^{\circ}C$, the largest quantity was 253.76 mg/g at pH 1 and 460.625mg/g at pH 13, but the smallest quantity is 139.375mg/g at pH 5 as known. 4. The dissolved crude protein from the cocoon shell and pupa was not different in quantity by treatment at 30$^{\circ}C$ or 60$^{\circ}C$. But dissolved crude protein was large quantity from cocoon shell more than pupa, as known. 5. The treatment of cocoon shell and pupa during 60 minutes at 100${\pm}$20$^{\circ}C$ was increased to the dissolved largest quantity of crude protein of 19.20％ at pH 1 and 22. 18％ at pH 13 from the cocoon shell and 6. 12％ at pH, an d 23.87％ at pH 13 from the pupa. But dissolved crude protein was increased to the larger quantity from pupa more than cocoon shell.

• Asian-Australasian Journal of Animal Sciences
• /
• v.27 no.11
• /
• pp.1615-1622
• /
• 2014

An accurate assessment of moisture content in feed ingredients is important because moisture influences the nutritional evaluation of feedstuffs. The objective of this study was to evaluate various methods for moisture content determination. In Exp. 1, the weight loss on drying (LOD) of corn, soybean meal (SBM), distillers dried grains with solubles (DDGS), whey permeate, whey powder, spray-dried porcine plasma (SDPP), fish meal, and a mixed diet of these 7 ingredients were measured by oven drying at $135^{\circ}C$ for 2 h. Additionally, the samples were dried at $105^{\circ}C$ for 3, 6, 9, 12, or 15 h. The LOD contents of the DDGS, whey permeate, and whey powder measured by drying at $135^{\circ}C$ for 2 h were greater than the values measured by drying at $105^{\circ}C$ for 3 h (p<0.05). All samples except SDPP (p = 0.70) dried at $105^{\circ}C$ for 6, 9, 12, or 15 h caused more LOD compared with the samples dried for at $105^{\circ}C$ for 3 h (p<0.05). The LOD contents of the individual ingredients were additive when dried at $105^{\circ}C$ regardless of drying time. In Exp. 2, moisture contents of corn, SBM, wheat, whey permeate, whey powder, lactose, and 2 sources of DDGS (DDGS1 and DDGS2) were measured by the Karl Fischer method, oven drying at $135^{\circ}C$ for 2 h, and oven drying at $125^{\circ}C$, $115^{\circ}C$, $105^{\circ}C$, or $95^{\circ}C$ for increasing drying time from 1 to 24 h. Drying samples at $135^{\circ}C$ for 2 h resulted in higher moisture content in whey permeate (7.5% vs 3.0%), whey powder (7.7% vs 3.8%), DDGS1 (11.4% vs 7.5%), and DDGS2 (13.1% vs 8.8%) compared with the Karl Fischer method (p<0.05). Whey permeate and whey powder were considerably darkened as the drying time increased. In conclusion, drying samples at $135^{\circ}C$ for 2 h is not appropriate for determining the moisture content in whey permeate, whey powder, or DDGS as well as the mixed diet containing these ingredients. The oven-drying method at $105^{\circ}C$ for 5 to 6 h appears to be appropriate for whey permeate and whey powder, and at $105^{\circ}C$ for 2 to 3 h for DDGS.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.33 no.6
• /
• pp.559-564
• /
• 2000

We studied to find out the effect of water temperature on the egg development of pearl oyster, Pincata fucata martensii and Pacific oyster, Crassostrea gigas. The optimum water temperatures for egg development were $20{\~}25^{\circ}C$ in P. fucata martensii and $15{\~}25^{\circ}C$ in C. gigas. The required time from fertilization to D-shaped lana was $41.7\;hours\;at\;20^{\circ}C$ and 27.5 hours at $25^{\circ}C$ in P. fucata martensii, and 35.3 hours at $15^{\circ}C$, 26.3 hours at $20^{\circ}C$ and 17.6 hours at$ 25^{\circ}C$ in C. gigas, respectively. The relationships between the water temperature ($WT:^{\circ}C$) and the required time (h: hour) from fertilization to each developmental stage were given as follows; P. fucata martensii Up to 8-cell $$1/h=0.0463WT-0.6945 (r^2=0.9702)$$ Up to morula $$1/h=0.0196WT-0.2184 (r^2=0.8118)$$ Up to trochophore $$1/h=0.0076WT-0.0802 (r^2=0.8756)$$ Up to D-shaped larva $$1/h=0.0031WT-0.0380 (r^2=0.9075)$$ C. gigas Up to 8-cell $$1/h=0.0210WT-0.1123 (r^2=0.9862)$$ Up to morula $$1/h=0.0143WT-0.1077 (r^2=0.9833)$$ Up to trochophore $$1/h=0.0052WT-0.0218 (r^2=0.9857)$$ Up to D-shaped lawn $$1/h=0.0029WT-0.0170 (r^2=0.9689)$$ Biological minimum temperature for egg development of P. fucata martensii and C. gigas was calculated as $$12.3^{\circ}C and 5.7{\circ}C$$, respectively.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.322.1-322.1
• /
• 2014

Many research groups have studied tandem or multi-junction cells to overcome this low efficiency and degradation. In multi-junction cells, band-gap engineering of each absorb layer is needed to absorb the light at various wavelengths efficiently. Various absorption layers can be formed using multi-junctions, such as hydrogenated amorphous silicon carbide (a-SiC:H), amorphous silicon germanium (a-SiGe:H) and microcrystalline silicon (${\mu}c$-Si:H), etc. Among them, ${\mu}c$-Si:H is the bottom absorber material because it has a low band-gap and does not exhibit light-induced degradation like amorphous silicon. Nevertheless, ${\mu}c$-Si:H requires a much thicker material (>2 mm) to absorb sufficient light due to its smaller light absorption coefficient, highlighting the need for a high growth rate for productivity. ${\mu}c$-SiGe:H has a much higher absorption coefficient than ${\mu}c$-Si:H at the low energy wavelength, meaning that the thickness of the absorption layer can be decreased to less than half that of ${\mu}c$-Si:H. ${\mu}c$-SiGe:H films were prepared using 40 MHz very high frequency PECVD method at 1 Torr. SiH4 and GeH4 were used as a reactive gas and H2 was used as a dilution gas. In this study, the ${\mu}c$-SiGe:H layer for triple solar cells applications was performed to optimize the film properties.

• Analytical Science and Technology
• /
• v.20 no.4
• /
• pp.355-360
• /
• 2007

The title complex, $(C_3H_{12}N_2)[\{Cd(H_2O)(C_6H_5O_7)\}_2]{\cdot}6H_2O$, I, has been prepared and its structure characterized by FT-IR, EDS, elemental analysis, ICP-AES, and X-ray single crystallography. It is triclinic system, $P{\bar{1}}$ space group with a = 10.236(2), b = 11.318(2), c = $13.198(2){\AA}$, ${\alpha}=77.95(1)^{\circ}$, ${\beta}=68.10(1)^{\circ}$, ${\gamma}=78.12(1)^{\circ}$, V = $1373.5(3){\AA}^3$, Z = 2. Complex I has constituted by protonated 1,3-diaminopropane cations, citrate coordinated cadmium(II) anions, and free water molecules. The central cadmium atoms have a capped trigonal prism geometry by seven coordination with six oxygen atoms of three different citrate ligands and one water molecule. Citrate ligands are bridged to three different cadmium atoms. Each cadmium atom is linked by carboxylate and hydroxyl groups of citrate ligand to construct an one-dimensional ladder-type assembly structure. The polymeric crystal structure is stabilized by three-dimensional networks of the intermolecular O-H${\cdots}$O and N-H${\cdots}$O hydrogen-bonding interaction.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.2
• /
• pp.445-448
• /
• 2009

This study examined the effect of the uptake of one and two electrons on the atomic structure of three isomers of $C_{20}$ clusters, namely the ring, bowl (corannulene like), and cage (the smallest fullerene). Geometry optimizations were performed using the hybrid density functional (B3LYP) methods for neutral, singly and doubly charged $C_{20},\;{C_{20}}^-,and\;{C_{20}}^{2-}$. These results show that the symmetry of the lowest energies for ring and bowl isomers were not changed, whereas the increasing order of energy for the cage (the smallest fullerene) isomers was changed from $D_{2h}\;<\;C_{2h}\;{\leq}\;C_2\;of\;C_{20}\;through\;Ci\;<\;C_{2h}\;<\;C_2\;<\;D_{2h}\;of\;{C_{20}}^-\;to\;Ci\;<\;C_2\;<\;D_{2h}\;<\;C_{2h}\;of\;{C_{20}}^{2-}$. The reduced symmetry isomers of the cage have comparative energy and the ground state symmetry of the neutral and single and double charged $C_{20}$ decreased with increasing number of electrons taken up in the point of energetics. Interestingly, the difference in energy between the ground state and the next higher energy state of ${C_{20}}^{2-}$ was 3.5kcal/mol, which is the largest energy gap of the neutral, single anion and double anion of the cage isomers examined.

• Bulletin of the Korean Chemical Society
• /
• v.14 no.1
• /
• pp.101-107
• /
• 1993

Ab initio calculations are carried out at the 6-311G$^{**}$ level for the $C_{2v}$ interactions of Be and Li atoms with acetylene molecule. The main contribution to the deep minima on the $^3B_2\;BeC_2H_2\;and\;^2B_2 LiC_2H_2$ potential energy curves is the b_2\;(2p(3b_2)-l{\pi}_g^*(4b_2))$ interaction, the $a_1\;(2s(6a_1)-I{\pi}_u(5a_1))$ interaction playing a relatively minor role. The exo deflection of the C-H bonds is basically favored, as in the $b_2$ interaction, due to steric crowding between the metal and H atoms, but the strong in-phase orbital interaction, or mixing, of the $a_1$ symmetry hydrogen orbital with the $5a'_1,\;6a'_1,\;and\;7a'_1$ orbitals can cause a small endo deflection in the repulsive complexes. The Be complex is more stable than the Li complex due to the double occupancy of the 2s orbital in Be. The stability and structure of the $MC_2H_2$ complexes are in general determined by the occupancy of the singly occupied frontier orbitals.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.3
• /
• pp.894-898
• /
• 2011

The first example of lead compound from $Pb(NO_3)_2$ and $H_3L$ N-heterocyclic ligand $(H_3L\;=\;(HO_2C)_2(C_3N_2)(C_3H_7)CH_2(C_6H_4)(C_6H_3)CO_2H)$, $[Pb_4(L')_4]{\cdot}5H_2O$ 1 (L' = OOC$(C_3H_7)(C_3N_2)CH_2(C_6H_4)(C_6H_3)COO)$, has been obtained under hydrothermal condition by decarboxylation, and characterized by elemental analysis, IR, TGDTA, and single-crystal X-ray diffraction. Compound 1 possesses a rare two-dimensional upper-lower offset terrace-like layer structure. In 1, crystallographic distinct Pb(II) ion adopts five-coordination geometry, and two lattice water molecules occupy the voids between 2-D layers. Results of solid state fluorescence measurement indicate that the emission band 458 nm may be assigned to $\pi^*-n$ and $\pi^*-\pi$ electronic transitions within the aromatic systems of the ligand L', however, the emission bands centred at 555 nm, 600 nm and 719 nm may be derived from phosphorescent emission ($\lambda_{excitation}$ = 390 nm).