• Journal of the Korea Organic Resources Recycling Association
• /
• v.27 no.1
• /
• pp.5-14
• /
• 2019

The objective of this study was investigated the effect of organic fertilizer(OF) application on the grain yield, protein content, and soil chemical properties in rice cultivation to evaluate the replacement ratio of OF based on basal fertilization of inorganic(nitrogen) fertilizer, In case of soil 1 with optimum range of organic matter for rice growth, the grain yield of rice in 70% and 100% treatments of OF were higher than the other treatments. In soil 2 with higher than the optimum range of soil organic matter, the grain yield of rice of NPK, 30%, 70%, 100%, and 300% treatments of OF showed no significant difference. When the protein criteria of rice quality was below 7%, the treatment of 30%, 70%, and 100% using OF in soil 1 were satisfied with protein criteria of rice. In case of soil 1, ammonium nitrogen content, electrical conductivity, and the organic matter in 30%, 70%, 100%, 300% treatments of OF showed similar tendency to NPK treatment. These results suggested that the substitution ratio of OF 70~100% could be appropriate to increase the yield and commercial quality for rice.

• Journal of Powder Materials
• /
• v.15 no.3
• /
• pp.182-187
• /
• 2008

Carbon was known to be one of effective additives which can improve the flux pinning of $MgB_2$ at high magnetic fields. In this study, glycerin $(C_3H_8O_3)$ was selected as a chemical carbon source for the improvement of critical current density of $MgB_2$. In order to replace some of boron atoms by carbon atoms, the boron powder was heat-treated with liquid glycerin. The glycerin-treated boron powder was mixed with an appropriate amount of magnesium powder to $MgB_2$ composition and the powder pallets were heat treated at $650^{\circ}C\;and\;900^{\circ}C$ for 30 min in a flowing argon gas. It was found that the superconducting transition temperature $(T_c)$ of $Mg(B_{1-x}C_x)_2$ prepared using glycerin-treated boron powder was 36.6 K, which is slightly smaller than $T_c$(37.1 K) of undoped $MgB_2$. The critical current density $(J_c)$ of $Mg(B_{1-x}C_x)_2$ was higher than that of undoped $MgB_2$ and the $T_c$ improvement effect was more remarkable at higher magnetic fields. The $T_c$, decrease and $J_c$ increase associated with the glycerin treatment for boron powder was explained in terms of the carbon substitution to boron site.

• Applied Chemistry for Engineering
• /
• v.20 no.6
• /
• pp.603-611
• /
• 2009

Thermotropic liquid crystalline behavior of a homologous series of penta-O-4-{4'-(cyanophenylazo)phenoxy}alkyl-D-glucopyranoses(CAGETn, n = 2~10, the number of methylene units in the spacer) has been investigated. The CAGETn with n of 2 and 7 exhibited enantiotropic nematic phases whereas other derivatives showed monotropic nematic phases. This is the first report of glucose derivatives that form thermotropic nematic phases. The isotropic-nematic transition temperatures ($T_{iNS}$) of CAGETns and their entropy variation at $T_{iN}$ showed the odd-even effect as a function of n. This behavior was rationalized in terms of the change in the average shape of the side chains as the parity of the spacer is varied. This rationalization also accounts for the observed variation of nematic-crystalline phase transition temperatures ($T_{NkS}$) and associoated entropy change at $T_{Nk}$. The entropy change at $T_{iN}$ or $T_{Nk}$ reaches a mininum at n = 3, before it increases again for n = 4. This may be attributed to the difference in the arrangement of the side groups. The mesophase properties of CAGETns were entirely different from those reported for partially or fully alkylated glucopyranoses. This result suggests that the degree of substitution and chemical structure of the substituents play an important role in the formation of the mesophase structures in the liquid crystals.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.12
• /
• pp.3588-3592
• /
• 2010

Second-order rate constants ($k_N$) have been measured spectrophotometrically for nucleophilic substitution reactions of 2-pyridyl X-substituted benzoates 8a-e with a series of alicyclic secondary amines in $H_2O$ at $25.0{\pm}0.1^{\circ}C$. The $k_N$ values for the reactions of 8a-e are slightly smaller than the corresponding reactions of 4-nitrophenyl X-substituted benzoates 1a-e (e.g., $kN^{1a-e}/k_N^{8a-e}$ = 1.1 ~ 3.1), although 2-pyridinolate in 8a-e is ca. 4.5 $pK_a$ units more basic than 4-nitrophenolate in 1a-e. The Br$\o$nsted-type plot for the aminolysis of 8c (X = H) is linear with $\beta_{nuc}$ = 0.77 and $R^2$ = 0.991 (Figure 1), which is typical for reactions reported previously to proceed through a stepwise mechanism with breakdown of a zwitterionic tetrahedral intermediate $T^{\pm}$ being the rate-determining step (RDS), e.g., aminolysis of 4-nitrophenyl benzoate 1c. The Hammett plot for the reactions of 8a-e with piperidine consists of two intersecting straight lines (Figure 2), i.e., $\rho$ = 1.71 for substrates possessing an electron-donating group (EDG) while $\rho$ = 0.86 for those bearing an electron-withdrawing group (EWG). Traditionally, such a nonlinear Hammett plot has been interpreted as a change in RDS upon changing substituent X in the benzoyl moiety. However, it has been proposed that the nonlinear Hammett is not due to a change in RDS since the corresponding Yukawa-Tsuno plot exhibits excellent linear correlation with $\rho$ = 0.85 and r = 0.62 ($R^2$ = 0.995, Figure 3). Stabilization of substrates 8a-e in the ground state has been concluded to be responsible for the nonlinear Hammett plot.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.12
• /
• pp.3795-3799
• /
• 2013

The second-order rate constants ($k_N$) have been measured spectrophotometrically for nucleophilic substitution reactions of Y-substituted-phenyl 2-methylbenzoates (6a-e) with a series of cyclic secondary amines in MeCN at $25.0{\pm}0.1^{\circ}C$. Comparison of the $k_N$ values for the reactions of 4-nitrophenyl 2-methylbenzoate (6d) with those reported previously for the corresponding reactions of 4-nitrophenyl 2-methoxybenzoate (5) reveals that 6d is significantly less reactive than 5, indicating that modification of 2-MeO in the benzoyl moiety of 5 by 2-Me (i.e., $5{\rightarrow}6d$) causes a significant decrease in reactivity. This supports our previous report that aminolysis of 5 proceeds through a six-membered cyclic intermediate, which is highly stabilized through intramolecular H-bonding interactions. The Br${\o}$nsted-type plot for the reactions of 6d with a series of cyclic secondary amines is linear with ${\beta}_{nuc}=0.71$, which appears to be a lower limit of ${\beta}_{nuc}$ for a stepwise mechanism with breakdown of an intermediate ($T^{\pm}$) being rate-determining step (RDS). The Br${\o}$nsted-type plot for the reactions of 6a-e with piperidine is curved, i.e., the slope of Br${\o}$nsted-type plot (${\beta}_{lg}$) decreases from -1.05 to -0.41 as the leaving-group basicity decreases. The nonlinear Br${\o}$nsted-type plot has been taken as evidence for a stepwise mechanism with a change in RDS (e.g., from the $k_2$ step to the $k_1$ process as the leaving-group basicity decreases). Dissection of $k_N$ into the microscopic rate constants associated with the reactions of 6a-e with piperidine (e.g., $k_1$ and $k_2/k_{-1}$ ratio) also supports the proposed mechanism.

• Asia pacific journal of information systems
• /
• v.20 no.3
• /
• pp.191-204
• /
• 2010

Recently, the CO2 emission and energy consumption have become critical global issues to decide the future of nations. Especially, the spread of IT products and the increased use of internet and web applications result in the energy consumption and CO2 emission of IT industry though information technologies drive global economic growth. EU, the United States, Japan and other developed countries are using IT related environmental regulations such as WEEE(Waste Electrical and Electronic Equipment), RoHS(Restriction of the use of Certain Hazardous Substance), REACH(Registration, Evaluation, Authorization and Restriction of CHemicals) and EuP(Energy using Product), and have established systematic green business/IT strategies to enhance the competitiveness of IT industry. For example, the Japan government proposed the "Green IT initiative" for being compatible with economic growth and environmental protection. Not only energy saving technologies but energy saving systems have been developed for accomplishing sustainable development. Korea's CO2 emission and energy consumption continuously have grown at comparatively high rates. They are related to its industrial structure depending on high energy-consuming industries such as iron and steel Industry, automotive industry, shipbuilding industry, semiconductor industry, and so on. In particular, export proportion of IT manufacturing is quite high in Korea. For example, the global market share of the semiconductor such as DRAM was about 80% in 2008. Accordingly, Korea needs to establish a systematic strategy to respond to the global environmental regulations and to maintain competitiveness in the IT industry. However, green competitiveness of Korea ranked 11th among 15 major countries and R&D budget for green technology is not large enough to develop energy-saving technologies for infrastructure and value chain of low-carbon society though that grows at high rates. Moreover, there are no concrete action plans in Korea. This research aims to deduce the priorities of the Korean green business/IT strategies to use multi attribute weighted average method. We selected a panel of 19 experts who work at the green business related firms such as HP, IBM, Fujitsu and so on, and selected six assessment indices such as the urgency of the technology development, the technology gap between Korea and the developed countries, the effect of import substitution, the spillover effect of technology, the market growth, and the export potential of the package or stand-alone products by existing literature review. We submitted questionnaires at approximately weekly intervals to them for priorities of the green business/IT strategies. The strategies broadly classify as follows. The first strategy which consists of the green business/IT policy and standardization, process and performance management and IT industry and legislative alignment relates to government's role in the green economy. The second strategy relates to IT to support environment sustainability such as the travel and ways of working management, printer output and recycling, intelligent building, printer rationalization and collaboration and connectivity. The last strategy relates to green IT systems, services and usage such as the data center consolidation and energy management, hardware recycle decommission, server and storage virtualization, device power management, and service supplier management. All the questionnaires were assessed via a five-point Likert scale ranging from "very little" to "very large." Our findings show that the IT to support environment sustainability is prior to the other strategies. In detail, the green business /IT policy and standardization is the most important in the government's role. The strategies of intelligent building and the travel and ways of working management are prior to the others for supporting environment sustainability. Finally, the strategies for the data center consolidation and energy management and server and storage virtualization have the huge influence for green IT systems, services and usage This research results the following implications. The amount of energy consumption and CO2 emissions of IT equipment including electrical business equipment will need to be clearly indicated in order to manage the effect of green business/IT strategy. And it is necessary to develop tools that measure the performance of green business/IT by each step. Additionally, intelligent building could grow up in energy-saving, growth of low carbon and related industries together. It is necessary to expand the affect of virtualization though adjusting and controlling the relationship between the management teams.

• Journal of Korean Society of Forest Science
• /
• v.88 no.1
• /
• pp.117-123
• /
• 1999

Consumer surplus is to be a value concerning a time horizon. Especially it is very important how long time horizon would be chosen in contingent market. This study aimed to provide causes of difference recreation benefits through discount rate in many aspects. The data were collected by personal interviews with visitors in Songnisan National Park. The respondents answered yes or no, dichotomous choice, on recreation benefits according to a chosen time horizon, one year or five years. The probit model was used in the analysis. In order to avoid the truncation bias of upper bound, the median was chosen as the recreation benefits of visitor. As the result, the value was evaluated to be 16,569 Won for one year and 27,111 Won for five years. The discount rate is estimated 153% annually to coincide different recreation benefits. The reasons of the high discount rate were to be interpreted as following five types : (1)uncertainty of future consumption (2)increasing of probability of the substitution owing to increasing of time horizon (3)recognization of different time horizons (4) effect by the price ratio of goods and utility function (5) overestimation of the recreation benefits owing to a basic premium of payment vehicle.

• Korean Journal of Mineralogy and Petrology
• /
• v.36 no.4
• /
• pp.355-363
• /
• 2023

In this study, we explore the nature of clumped isotopes of H₂O molecule using quantum chemical calculations. Particularly, we estimated the relative clumping strength between diverse isotopologues, consisting of oxygen (¹⁶O, ¹⁷O, and ¹⁸O) and hydrogen (hydrogen, deuterium, and tritium) isotopes and quantify the effect of temperature on the extent of isotope clumping. The optimized equilibrium bond lengths and the bond angles of the molecules are 0.9631-0.9633 Å and 104.59-104.62°, respectively, and show a negligible variation among the isotopologues. The calculated frequencies of the modes of H₂O molecules decrease as isotope mass number increases, and show a more prominent change with varying hydrogen isotopes over those with oxygen isotopes. The equilibrium constants of isotope substitution reactions involving these isotopologues reveal a greater effect of hydrogen mass number than oxygen mass number. The calculated equilibrium constants of clumping reaction for four heavy isotopologues showed a strong correlation; particularly, the relative clumping strength of three isotopologues was 1.86 times (HT¹⁸O), 1.16 times (HT¹⁷O), and 0.703 times (HD¹⁷O) relative to HD¹⁸O, respectively. The relative clumping strength decreases with increasing temperature, and therefore, has potential for a novel paleo-temperature proxy. The current calculation results highlight the first theoretical study to establish the nature of clumped isotope fractions in H₂O including ¹⁷O and tritium. The current results help to account for diverse geochemical processes in earth's surface environments. Future efforts include the calculations of isotope fractionations among various phases of H₂O isotopologues with a full consideration of the effect of anharmonicity in molecular vibration.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.29 no.1
• /
• pp.37-42
• /
• 2009

This experiment was conducted to investigate the effect of cattle manure application on macro contents change in pasture. The treatment consisted of T1: 100% chemical fertilizer (CF 100%), T2: 50% CF+50% cattle manure (CM), T3: 25% CF+75% CM, T4: 100% CM 100%, T5: 100% CM(1st year (yr.) +100% CF (2nd yr.)+100% CM (3rd yr.), T6: 100% CM (1st yr.)+100% CF (2nd yr.)+100% CF (3rd yr.). The highest substitution effect of chemical fertilizer with cattle manure indicated by the highest yield of 11,169 kg/ha was obtained from the application of 100% CM (1 yr.) + 100% CF (2 yr.). The forage yield of plots applied with 100% CM (1 yr.) + 100% CF(2 yr.) was only 4% more than the yield of plots applied with 100% CM. It was only 3% less than the yield of plots applied with 100% CF. In this study, cattle manure application recorded slightly lower forage dry matter (DM) yield than 100% CF application but they were statistically comparable on the third year of production. The all treatments have narrow range of P, K, Ca, Mg and Na contents $0.25{\sim}0.32%,\;3.08{\sim}3.71%,\;0.42{\sim}0.55%,\;0.21{\sim}0.38%$ and $0.08{\sim}0.15%$.

• Journal of Korean Academy of Nursing
• /
• v.21 no.2
• /
• pp.129-149
• /
• 1991

Circadian rhythm is entrained in the 24-hour time interval by periodic factors in the environment, known as zeitgeber. But most rotating work schedules are outside the range of the entrainment of the pacemaker timing the human circadian sleep - wake cycle. It has been postulated that physiological and emotional disturbances occur in most human functions when the circadian rhythm is disturbed. So application of circadian principles to the design of shift schedules can aid in maintaining the temporal integrity of the circadian system and thereby minimize for the shift worker any detrimental consequences of circadian disruption. This study was a quasi-experimental study to test the effect of shift intervals for the clinical nurse on the circadian rhythm. Twenty nurses newly employed in general units of two hospitals were selected as an experimental group and twelve college nursing students as a control group. Both groups were selected according to an established criteria using a purposive sampling technique. Ten subjects were assigned to a weekly shift group and another ten to a biweekly shift group engaged in a semi -continuous shift schedule(sunday off) with a backward direction, that is, morning -evening - night shift. The control group worked a morning shift for 42 days. Oral temperature rhythm, waking tim, sleep - wake cycle, fatigue, and mental performance were measured during the experimental period. The data collection period was from April 30, 1990 to June 10, 1990. MANOVA, paired t-test, ANOVA, and Student Newman Keuls method were used for statistical analysis. The results are summarized as follows. 1. Phase delay in the acrophase of temperature rhythm was shown according to the backward rotating shift. A complete adaptation to work on the night shift was achieved between the sixth and ninth day of the night shift. 2. There was no difference in either waking time or sleep- wake cycle according to the duration of the working day for every shift group. Significant difference was found in the waking time and the sleep -wake cycle for subjects on the morning, evening, and night shift in both of the shift groups(weekly shift group : λ＝0.121, p＜0.01, λ＝0.112, p＜0.01, biweekly shift group : λ＝0.116, p＜0.01, λ＝0.084, p＜0.01). 3. There was no difference in fatigue between the first working day and the last working day for the control group and for the biweekly shift group. In the weekly shift group, physical fatigue was significantly different for the first day and the sixth day of the night shift(t＝-2.28, p＜0.05). Physical fatigue and total fatigue on the first day of the night shift showed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝5.79, p＜0.01, F＝4.56, p＜0.05). There was a significant difference between the shift groups and the control group(p＜0.05), Physical fatigue, neurosensory fatigue and total fatigue on the last day of the night shift showed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝12.65, p＜0.01, F＝7.77, p＜0.01, F＝9.68, p＜0.01). There was a significant difference between the shift groups and the control group(p＜0.05). 4. No difference in mental performance was seen between the first day and the last day of work in each case. An arithmatic test on the first day of the night shift revealed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝3.79, p＜0.05). There was a significant difference between the shift groups and the control group(p＜0.05) . The digital symbol substitution test and the arithmetic test on the last day of the night shift showed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝3.68, p＜0.05, F＝5.55, p＜0.01), and both showed a significant difference between the shift groups and the control group(p＜0.05). Accordingly, this study showed that during night duty, the waking time, sleep- wake cycle, and fatigue increased and mental performance decreased compared with morning and evening duty. It was also found that the weekly shift group had a higher fatigue score on the sixth day of night duty as compared to the -first day, but the waking time, sleep- wake cycle, and mental performance revealed no difference for the duration of the night duty or between shift groups, and complete adaptation of temperature rhythm was achieved between the sixth and ninth day of night duty. It is possible to conclude from these results that for intermediate circadian type in a healthy young woman, a biweekly shift system is more compatible with the circadian timing system than weekly shift system.