• Title/Summary/Keyword: secondary hardness

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Affecting Factors of Nurses' Burnout in Secondary General Hospitals (2차 종합병원 간호사의 소진에 영향을 미치는 요인 - 심리.성격 특성과 업무특성중심으로-)

  • Park, Seung-Mi;Jang, In-Sun;Choi, Jeong-Sil
    • Journal of Korean Academy of Nursing Administration
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    • v.17 no.4
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    • pp.474-483
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    • 2011
  • Purpose: This study was conducted to identify factors affecting nurses' burnout in secondary general hospitals. Methods: Data were collected through structured questionnaires from 241 nurses working at the secondary general hospitals with below 400 beds in the P, C, and S city between April and May, 2009. Data analysis was done with independent t test, ANOVA, Pearson correlation coefficient, and multiple stepwise multiple regression with SPSS WIN v 17.0. Results: Burnout was significantly different according to religion, age, clinical experiences, and shift work. Burnout score of the subjects was 58/100. Burnout of the subjects were positively correlated with job stress and negatively correlated with hardness, self efficiency, self esteem, spiritual wellbeing, social support, and job satisfaction. The explained variances for burnout was 51.8% and factors affecting nurses' burnout in secondary general hospitals were job stress, hardness, self efficiency, job satisfaction and shift work. Conclusion: These results showed the significant factors fo nurses' burnout in secondary general hospitals. These findings can be utilized to development of strategies for reducing job stress and enhancing hardness, self efficiency and job satisfaction.

Effect of Sintering Temperature, Heat Treatment and Tempering on Hardness of SH737-2Cu-0.9C Sintered Samples

  • Anand, S.;Verma, N.;Upadhyaya, A.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.555-556
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    • 2006
  • The study examines hardness pattern of SH737-2Cu-.9C samples transient liquid phase sintered at different temperatures viz. $1120^{\circ}C$, $1180^{\circ}C$ and $1250^{\circ}C$, heat treated by various methods and then tempered at different temperatures. Sintered samples were characterized for density and densification parameter, and austenitized at $900^{\circ}C$, subsequently cooled by four different methods viz. annealing, normalizing, oil and brine quenching. Hardness pattern was found minimum for air cooled and maximum for brine quenched, and samples sintered at $1250^{\circ}C$ had relatively higher hardness. The O.Q and B.Q samples were then tempered at $200^{\circ}C$, $400^{\circ}C$, $600^{\circ}C$ and $700^{\circ}C$. Hardness pattern typically showed secondary hardness taking place, with maximum around $600^{\circ}C$.

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Friction and Wear Characteristics of Gray Cast Iron Surface Processed by Broaching Method (브로칭 가공된 회주철 소재 표면의 마찰 및 마모 특성)

  • Kwon, Mun-Seong;Kang, Kyeong-Hee;Kim, Dae-Eun
    • Tribology and Lubricants
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    • v.34 no.6
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    • pp.262-269
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    • 2018
  • In this work the friction and wear characteristics of the gray cast iron surface processed by broaching method, which is widely used in the machinery industry, were investigated. The broaching process is mainly used for mass production because it has high dimensional accuracy and processing speed, but the defects on surface can be easily generated. In order to improve the tribological characteristics, the approach was to reduce the roughness and hardness of the surface by adding a machining process to the broaching specimen. The secondary machining process using abrasive grains produces low roughness and hardness than broaching because it has high tool accuracy and removes the work hardened surface. The friction coefficient and the wear rate were assessed using a reciprocating-type tribotester to analyze the effects of surface finishing on the tribological properties. The friction tests were conducted under dry and lubricated conditions. The test results showed that the reduction of surface roughness and hardness through secondary machining process in lubricated condition improved the friction and wear characteristics. The reason why the same results did not appear in a dry condition was that wear occurred more rapidly than in lubricated condition. Thus, the positive effect of roughness and hardness of the surface obtained through the secondary machining process was not observed.

Influence of W Additions on the Corrosion Characteristics and Hardness of Super Duplex Stainless Steel (슈퍼 듀플렉스 내식강의 부식특성 및 경도에 미치는 텅스텐 첨가의 영향)

  • Yun-Gi Han;Jeong-Min Kim
    • Journal of the Korean Society for Heat Treatment
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    • v.36 no.5
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    • pp.261-269
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    • 2023
  • This study aims to investigate the effects of tungsten additions on the microstructure, corrosion characteristics, and hardness of super duplex stainless steel heat-treated at two different annealing temperatures. Under the annealing temperature of 1100℃, the microstructure of the stainless steels consisted mainly of ferrite, while under the annealing temperature of 1000℃, significant amounts of austenite and secondary phases were also observed. In terms of corrosion characteristics in 3.5 wt%NaCl solution, there was not a significant difference due to W addition at the 1100℃ conditions. However, at the 1000℃, a tendency of decreased corrosion resistance was observed with increasing the tungsten content. On the other hand, the micro-hardness of the stainless steel heat-treated 1000℃ showed an increasing trend with tungsten addition. This increase can be mainly attributed to the higher fraction of secondary phases, primarily sigma, known for their high hardness.

The Effect of Current and Preheat Temperature on Structure and Hardness of Stellite 12 Alloy Overlayer by PTA Process (PTA법에 의한 스텔라이트 12 합금 육성층의 조직과 경도에 미치는 전류와 예열온도의 영향)

  • Jung, B.H.;Kim, M.G.;Kim, G.D.;Kim, M.Y.;Lee, S.Y.
    • Journal of the Korean Society for Heat Treatment
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    • v.13 no.4
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    • pp.246-252
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    • 2000
  • Stellite 12 alloy-powder was overlaid on 410 stainless steel valve seat using plasma transferred arc(PTA) process. Variation of characteristic of microstructure and hardness of deposit with current(90~150 A) and preheat temperature(R.T.~$400^{\circ}C$) was investigated. Important conclusion obtained are as follows; All welding conditions used produced a sound deposit layer with no defect in single pass welding. The maximum deposit had 4.0~4.8 mm in thickness and its bead width was increased with increase of current and preheat temperature. The deposit showed hypoeutectic microstruture, which was consisting of primary cobalt dendrite and networked $M_7C_3$ type eutectic carbides. The amount of eutectic carbides was decreased and its dendritic secondary arm spacing was increased with increase of current. Hardness of the deposit was decreased with increase of current. Preheat temperature up to $400^{\circ}C$, however, showed little influence on the hardness and microstructure. The hardness was also influenced by diluted Fe content near the interface in addition to microstructure and dendritic secondary arm spacing. Hot hardness at $500^{\circ}C$ showed higher than 300 HV.

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Effects of Two-Step Aging Treatment on the Mechanical Properties of 6061 Al Alloy (A 6061 합금의 기계적 특성에 미치는 2단시효의 영향)

  • Lee, Bo-Bae;Im, Hang-Joon;Jeong, Geol-Chae.
    • Journal of the Korean Society for Heat Treatment
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    • v.32 no.2
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    • pp.57-60
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    • 2019
  • The impact of two-step treatment on the mechanical properties of the 6061 Al alloy was investigated by testing the hardness and electrical conductance values. After two-step aging treatment, the hardness and electrical conductivity of the alloy was increased, and if the first aging treatment temperature was lower than the secondary aging treatment temperature, both the hardness and the electrical conductivity were not increased. The higher the temperature of the first aging treatment, the higher the hardness. The temperature of the first aging treatment is $175^{\circ}C$, $150^{\circ}C$, $120^{\circ}C$, and the second is $175^{\circ}C$ and $120^{\circ}C$.

The Effect of Ausforming Process on Mechanical Properties of Ultrahigh Strength Secondary Hardening Martensitic Steels (극초고강도 이차경화형 마르텐사이트강의 기계적성질에 미치는 오스포밍 공정의 영향)

  • Kim, S.B.;Won, Y.J.;Song, Y.B.;Cho, K.S.
    • Journal of the Korean Society for Heat Treatment
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    • v.34 no.4
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    • pp.179-184
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    • 2021
  • Two types of secondary hardening martensitic steels, 10Co-14Ni and 6Co-5Ni, were produced by vacuum induction melting to investigate the effect of ausforming process on mechanical properties. According to the results of present study, the alloy samples ausformed at low temperature indicated a rather low hardness level in overall aging time despite the refinement of martensite lath width. As the result can closely be related with the presence of primary carbides precipitated within the initial austenite matrix, we confirmed that, in ultrahigh strength secondary hardening martensitic alloy steels, the ausforming process can rather limit the degree of secondary hardening during the subsequent aging treatment.

The softening behavior of Mg-Li-Al(-Zr) alloys (Mg-Li-Al(-Zr) 합금의 연화현상)

  • Kim, Y.W.;Kwang, Y.H.;Lim, Y.J.;Kim, D.H.;Hong, C.P.
    • Journal of the Korean Society for Heat Treatment
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    • v.11 no.1
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    • pp.10-16
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    • 1998
  • The softening behavior of squeeze cast Mg-Li-Al and Mg-Li-Al-Zr alloys have been investigated. The highest hardness values of Mg-Li-Al and Mg-Li-Al-Zr alloys were obtained after solution treatment at $400^{\circ}C$ for 1 hour. The hardness value, however, decreased as the aging temperature and time increased. Microstructural and calorometric analyses showed that quenched-microstructure changed from primary (${\alpha}$ and ${\beta}$)+secondary ${\alpha}$ to primary(${\alpha}$ and ${\beta}$)+secondary ${\alpha}+{\theta}$ after aging. The softening during aging was due to the coarsening of ${\theta}$ precipitates.

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Analysis for the secondary gamma-ray emission for glasses irradiated with various doses of fast neutron: Case study borate and silicate glasses

  • O.L. Tashlykov;V. Yu. Litovchenko;N.M. Aristov;K.A. Mahmoud
    • Nuclear Engineering and Technology
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    • v.55 no.7
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    • pp.2366-2372
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    • 2023
  • Are borate and silicate glasses suitable for working as shieling materials against fast neutrons? To correctly answer the above question, some silicate, and borate-based glasses were fabricated and irradiated with various doses of fast neutrons varied between 1.73 and 12.10 MGy. The color and hardness of the fabricated glasses were affected by the fast neutron fluence where the transparent glasses turned colored as well as the hardness of the fabricated glasses was decreased. The gamma-ray spectrometric analysis shows a high activity concentration produced in the barium borate glasses due to the formation of radioisotopes Ba-131 and Ba-133 reaches to 5.92E+05 Bq and 4.25E+03 Bq, respectively for sample Cd-5 Batch 3. Additionally, the gamma-ray spectrometric analysis for the sodium silicate glasses shows low activity concentrations emitted from isotopes formed due to the activation of Y2O3-associated impurities. These activities are low compared to that emitted by barium borate-based glasses.