• 대한금속재료학회지
• /
• 제48권3호
• /
• pp.262-267
• /
• 2010

$LiNi_{1-x}Mg_xO_2$(x=0, 0.025, 0.05, 0.075, 0.1) samples were synthesized by the solid-state reaction method. The crystal structure was analyzed by X-ray powder diffraction and Rietveld refinement. $LiNi_{1-x}Mg_xO_2$samples give single phases of hexagonal layered structures with a space group of R-3m. The calculated cation-anion distances and angles from the Rietveld refinement were changed with Mg contents in $LiNi_{1-x}Mg_xO_2$. The thicknesses of $NiO_2$ slabs were increased and the distances between the $NiO_2$ slabs were decreased with the increase in Mg contents in the samples. The electrical conductivities of sintered $LiNi_{1-x}Mg_xO_2$ samples were around $10^{-2}$ S/cm at room temperature. The electrochemical performances of $LiNi_{1-x}Mg_xO_2$were evaluated by coin cell test. Compared to $LiNiO_2$, $LiNi_{0.95}Mg_{0.05}O_2$ exhibited improved high-rate capability and cyclability due to the well-ordered layered structure by doping of Mg ion.

• 한국재료학회지
• /
• 제12권5호
• /
• pp.369-374
• /
• 2002

To investigate the corrosion behavior of Zr-1.0Nb-xSn (x=1.0, 1.5, 2.0 and 2.5wt. %)alloy system, the corrosion tests of Zr-1.0Nb-xSn alloys were carried out in steam at $400^{\circ}C$ for 125 days and in 70ppm LiOH solution at $360^{\circ}C$ for 180 days. The matrix microstructures of the test specimens were analyzed using TEM and the oxide structures on the test specimens were analyzed using XRD. It was found from the analyses that the more Sn content the alloy had, the faster it was corroded and with the increase of Sn content in the alloy the fraction of $t-ZrO_2$ to $m-ZrO_2$ was decreased. It was also found that the alloys having more Sn showed more dislocation density than those having less.

• 대한수학회보
• /
• 제50권2호
• /
• pp.485-498
• /
• 2013

In this paper, the Schur convexity is generalized to Schur $f$-convexity, which contains the Schur geometrical convexity, harmonic convexity and so on. When $f$ : ${\mathbb{R}}_+{\rightarrow}{\mathbb{R}}$ is defined as $f(x)=(x^m-1)/m$ if $m{\neq}0$ and $f(x)$ = ln $x$ if $m=0$, the necessary and sufficient conditions for $f$-convexity (is called Schur $m$-power convexity) of Gini means are given, which generalize and unify certain known results.

• 근관절건강학회지
• /
• 제25권2호
• /
• pp.84-91
• /
• 2018

Purpose: The purpose of this study was to identify the types of violence experienced by small and medium sized hospital nurses. Methods: Data were collected from March 1 to 30, 2017, using self-report questionnaires. Responses from 87 nurses were analyzed using descriptive statistics, $x^2$ test, Fisher's exact test, t-test. Results: The majority of the respondents experienced violence from patients (60.2%), visitors (25.5%), doctors (12.2%), and other staffs (2.0%). Verbal violence (80.5%) and physical threats (74.7%) were more frequent than physical violence (25.3%). Violence occurred throughout the hospital. However, verbal violence ($x^2=20.85$, p=.005) and physical threat ($x^2=20.80$, p=.006) were statistically significant according to the department. Violence occurred most frequently in surgical ward, followed by artificial kidney room, emergency room, and outpatient department. Conclusion: Most nurses are exposed to frequent violence. These results suggest that hospital should improve the respective organizational cultures and develop promotional programs and administrative policies to prevent violence. Also, hospitals should develop of violence intervention policies and education programs and counseling programs for nurses.

• 대한안전경영과학회지
• /
• 제12권4호
• /
• pp.73-80
• /
• 2010

The purpose of this study was to investigate the actual conditions of radiation safety supervision in animal clinics using inspection standard of X-ray generator for diagnosis. The surveys for inspection standard system, equipment condition, and safety supervision were carried out in 18 animal clinics randomly. The inspection standard included reproducibility of dose exposure, kVp, mAs, collimator accuracy test, collimator luminance test, X-ray view box luminance test, grounding system equipment test and external leakage current test. The surveys of equipment condition and safety supervision used one-on-one interview with 5 points measurement. As a result, 44.44% of reproducibility of dose exposure was proper, 81.25% of kVp test was good, and 100% of mAs test was appropriate. Also, 66.66% of collimator accuracy test was proper, 61.11% of collimator luminance test was good, 53.13% of X-ray view box luminance test was suitable. In addition, only 5.55% of grounding system equipment and ground resistance was proper, 63.64% of external leakage current test was appropriate in grounding system equipment test. The 100mA electric capacity of X-ray generator for diagnosis was popular with 44.44%, and its 55.56% was purchased used equipment. Monthly average of less than 50 times (61.11%) was top frequency in use, and no animal clinic had a thermo-luminescence dosimeter(TLD). The 16 animal clinics with radiation safety zone and 2 without radiation safety zone were appeared.

• 한국세라믹학회지
• /
• 제34권8호
• /
• pp.908-913
• /
• 1997

Multilayer NbCxC1-x/Y2O3/Ti were sputter-coated on the alumina substrate, starting with a 0.7 ㎛ thick NbCxC1-x layer grown on substrate, followed by 0.7 ㎛ thick Y2O3 layer and 1 ㎛ thick Ti layer. To find out the optimum conditions for thickness uniformity and adhesion, sputtering works have been done with the variation of sputtering power and Ar pressure. After vacuum annealing at 950℃ and 1000℃, the thermal stability of the NbCxC1-x/Y2O3/Ti coated alumina substrates has been investigated by peel off test. The coating scheme didn't cause any debonded layer after an annealing at 950℃ for 3hrs. However, it was peeled off after annealing at 1000℃ for 3hr. It was found that the thermal stability of Al2O3/NbCxC1-x/Y2O3/Ti coating scheme changed with the NbCxC1-x composition.

• 지역사회간호학회지
• /
• 제15권4호
• /
• pp.655-665
• /
• 2004

Purpose: This study was aimed to investigate the physical and psychological health status of the homeless in shelters, and to suggest the basic data for caring them. Method: Study subjects were 153 homeless people who were registered in the shelters of Dong-gu, Busan, between September 1st, 2003 and March 15th, 2004. Data on their physical health status were collected by measuring weight and height (BMI), taking X-rays (tuberculosis), testing blood (syphilis, glucose, HBsAb and HBsAb). Psychological health status was measured with Rosenberg's self-esteem scale and Beck's depression scale. Data were analyzed with descriptive statistics, $x^2-test$, t-test or F-test using SPSS (Win10.0), at 0=0.05, two tailed test. Results: Mean age was 42.8 years old, high school graduated was 43.8%, and 60.8% didn't have medical benefits. Singles were 47.7%, 34.7% had bad family relationships and 39.2% hoped to live with family, 96.1% had a normal in chest X-ray test, and 96.1% had negative syphilis test 92.2% were negative for hepatitis antigen, 51.0% were antibody, 25.5% had hypertension, and 60.8% had a normal BMI test, and 84.3% had a normal blood sugar test. 39.2% were severely depressed, and 75.8% had a normal self-esteem level. Conclusion: Physical health status of the homeless was relatively good. However, depression levels were high and self-esteem was low. Therefore, it is necessary to take an action to improve the psychological health status for the homeless.

• 한국응급구조학회지
• /
• 제3권1호
• /
• pp.20-32
• /
• 1999

The purpose of this retrospective research of 603 patients who were transferred to the emergency medical center of university hospital from 1 Jan, 1998 to 31 Jan, 1998 was making of basic data for emergency medical transfer system improvement countermeasure and the point at issue of overlapping reexamination ststus of patients transfered to emergency medical center of university hospital from 1,2 level hospital. The data analysis was done by SPSS, t-test, ANOVA, Pearson correlation. The results were as follows: 1. Male to female ratio was 1.7:1 and peak age group was patients over forties and under nine years of age(70.5%) 2. Traumatic patients were 17.8%, motor vehicle accident patients were 16.7% and Non-traumatic patients were 65.3%. Transferring hospital was divided into 2groups: primary hospital, secondary hospital. The majority was secondary hospital(73.3%). The result of symptom severity classification of patients transferred to 3rd emergency medical center was urgent patients 32.5%, emergency patients 33.58%, non-emergency patients 34.0% 3. Most highest score items amoung overlapping reexamination of patients transfered to emergency medical center of university hospital from 1,2 level hospital were CBC test, simple X-ray (0.93점), CBC test(0.97점), urin test(0.88점), chemistry test(0.94점), simple X-ray(0.98점), CT(0.42점), EKG(0.89점) amoung overlapping reexamination of motor vehicle accident patients were more higher reexamination score than traumatic patients and non-traumatic patients 4. CBC test(P<0.001), urin test(P<0.001), chemistry test(P<0.001), simple X-ray(P<0.001), CT(P<0.01), EKG(P<0.001) amoung overlapping reexamination of patients in 2 level hospital were more higher reexamination score than 1 level hospital patients 5. About symptom severity classification of patients transferred to 3rd emergency medical center, CBC test(P<0.001), urin test(P<0.001), chemistry test(P<0.001), simple X-ray(P<0.01), CT(P<0.001), EKG(P<0.001) amoung overlapping reexamination items in urgent patients were more higher reexamination score than other patients 6. Influencing variation for overlapping reexamination in hospital was CBC test(P<0.001), CT (P<0.001), MRI (P<0.05).

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 2001년도 추계학술발표회요약집
• /
• pp.249.1-249
• /
• 2001

• Journal of Animal Science and Technology
• /
• 제58권2호
• /
• pp.5.1-5.9
• /
• 2016

Background: The milk yield can be affected by the frequency of milking per day, in dairy cows. Previous studies have shown that the milk yield is increased by 6.25 % per lactation when the milking frequency is increased from 2 to 3 times per day while the somatic cell count is decreased. To investigate the effect of milking frequency (3X vs. 4X) on milk yield and it's genetic parameters in the first and second lactations of the Iranian Holstein dairy cows, a total of 142,604 test day (TD) records of milk yield were measured on 20,762 cows. Results: Heritability estimates of milk yield were 0.25 and 0.19 for 3X milking frequency and 0.34 and 0.26 for 4X milking frequency throughout the first and second lactations, respectively. Repeatability estimates of milk yield were 0.70 and 0.71 for 3X milking frequency and 0.76 and 0.77 for 4X milking frequency, respectively. In comparison with 3X milking frequency, the milk yield of the first and second lactations was increased by 11.6 and 12.2 %, respectively when 4X was used (p < 0.01). Conclusions: Results of this research demonstrated that increasing milking frequency led to an increase in heritability and repeatability of milk yield. The current investigation provided clear evidences for the benefits of using 4X milking frequency instead of 3X in Iranian Holstein dairy cows.