• Title/Summary/Keyword: AIN sample

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AIN Microstructure Evalution through Hg-porosimetry (수은침투법을 이용한 AIN 미세구조연구)

  • Lee, Hae-Weon;Yoon, Bok-Gyu;Hong, Kug-Sun
    • Analytical Science and Technology
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    • v.5 no.2
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    • pp.217-222
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    • 1992
  • An attempt was made to analyze green microstructure of AIN samples prepared by slip casting and dry pressing through Hg-porosimetry. Slip cast samples with narrow pore size distribation and high packing density showed higher sinterability and homogeneous distribution of second phase(s). Hg-porosimetry is and effective way to determine pore structure if "ink bottle" phenomenon does not occur. A comparison study with porosity measurement by quantitative microscopy showed that the effectiveness of Hg-porosimetry measurement could be extended to higher sintered density as long as pores remained open.

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Testing of EBELC classes of life distributions based on TTT-transform

  • Abu-Youssef, S.E.;Mohie El-Din, M.M.;Hassan, M.Kh.
    • International Journal of Reliability and Applications
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    • v.13 no.1
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    • pp.49-56
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    • 2012
  • Using total time on test transform (TTT), a new approach is taken for testing exponentiality versus the unknown age, exponential better than equilibrium life in convex ordering (EBELC). Selected critical values are tabulated for sample size n =2(2)50 and powers of the test are estimated for some commonly used distributions in reliability. Finally real example is presented to illustrate the theoretical results.

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Type of tooth movement during en masse retraction of the maxillary anterior teeth using labial versus lingual biocreative therapy in adults: A randomized clinical trial

  • Sadek, Mais M.;Sabet, Noha E.;Hassan, Islam T.
    • The korean journal of orthodontics
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    • v.49 no.6
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    • pp.381-392
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    • 2019
  • Objective: The objective of this two-arm parallel trial was to compare the type of tooth movement during en masse retraction of the maxillary anterior teeth using labial versus lingual biocreative therapy. Methods: Twenty-eight subjects were randomized in a 1 : 1 ratio to either the labial or lingual group. En masse anterior retraction was performed using labial biocreative therapy in group A and lingual biocreative therapy in group B. Cone beam computed tomography scans were taken before and after retraction and the primary outcome was the type of tooth movement during anterior retraction. Data were analyzed using paired t-tests for comparisons within each group and independent-sample t-test for comparison of the mean treatment changes between the two groups. Results: Significant differences were found between the two groups in relation to the type of tooth movement (labiolingual inclination of the central incisor; mean difference, $5.85{\pm}1.85^{\circ}$). The canine showed significant distal tipping in the lingual group (mean difference, $6.98{\pm}1.25^{\circ}$). The canine was significantly more intruded in the lingual group (mean difference, $1.67{\pm}0.49mm$). Good anchorage control and significant soft tissue changes occurred in both groups. No serious adverse effects were detected. Conclusions: With a 10-mm retraction hook, the labial biocreative technique with the reverse curve overlay provided anterior retraction with good torque control, while in the lingual group, anterior retraction occurred with controlled tipping movement with significant distal tipping and intrusion of the canine (trial registration: The trial was registered at ClinicalTrials.gov [NCT03239275]).

Nitrogenation of Coal Ash in the Presence of Carbon and Product Distributions of AlN, SiC and Si₃N₄ (석탄회의 탄소가 첨가된 질화반응과 AlN, SiC 그리고 Si₃N₄의 생성분포)

  • 양현수;홍원표;노재성;서동수;손응권
    • Journal of the Korean Ceramic Society
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    • v.27 no.8
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    • pp.956-956
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    • 1990
  • A nitrogenation of coal ash in the presence of carbon was carried out to examine the effects of reaction temperature, reaction time and carbon composition on the formation of AlN, SiC and Si3N4. Decreasing the particle size increased the formation of AlN and its maximum composition in the product was obtaiend under 1450∼1500℃, 2 hours of reaction time and about 30% of carbon addition(on the basis of sample weight). Compositions of SiC and Si3N4 were distributed to the opposite so that SiC showed a higher composition compared with Si3N4 at a lower temperature, a shorter reaction time and a greater carbon addition.

Community Economic Evaluation and Sample Distribution of a State Park: The Case of the Belum Royal State Park, Malaysia

  • AWANG MARIKAN, Dayang Affizzah;RAMBELI, Norimah;AZMAN, Nur Ain;RAMDAN, Mohamad Rohieszan
    • Journal of Distribution Science
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    • v.20 no.10
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    • pp.19-29
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    • 2022
  • Purpose: This study was conducted to gauge the economic evaluation and sample distribution of conserving the Belum Royal State Park (BRSP) in Perak, Malaysia and to identify factors influencing its use by the community. This study aims to examine community perception on the conservation of the Belum Royal State Park (BRSP) and maximum community's willingness to pay for park entry permits fees. Research design, data and methodology: A questionnaire survey was conducted involving a total of 280 respondents. The study adopted the Dichotomous Choice Contingent Valuation Approach (DC-CVM) and the Logistic Model, to estimate the maximum community's willingness to pay for park entry permits fees. Results: The results established that the factors of respondent's occupation, income, ecotourism influence on the BRSP and maximum entry price, significantly influenced visitors' decision on community's willingness to pay. The average community's willingness to pay was RM9.68 per person. Conclusions: In conclusion, surveillance and patrols in protected areas should be expanded. The extra expense for ensuring safety can be offset through income from ecotourism that should also benefit the local community on economic evaluation and equal distribution on the BRSP.

The Properties of GaN Grown by BVPE Method on the Si(111) Substrate with Pre-deposited Al Layer (Al 박막이 증착 된 Si(111) 기판 위에 HVPE 방법으로 성장한 GaN의 특성)

  • Shin Dae Hyun;Baek Shin Young;Lee Chang Min;Yi Sam Nyung;Kang Nam Lyong;Park Seoung Hwan
    • Journal of the Korean Vacuum Society
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    • v.14 no.4
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    • pp.201-206
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    • 2005
  • In this work, we tried to improve the fabrication process in HVPE (Hydride Vapor Phase Epitaxy) system by using Si(111) substrate with pre-deposited Al layer. PL measurements was done for samples with and without pre-deposited Al on Si and it was also examined the dependence of the optical characteristic properties on AlN buffer thickness for GaN/AIN/Al/Si. A sample with thin Al nucleation layer on Si substrate reveals a better optical property than the other. And it suggests that the thickness for AlN buffer layer with thin Al nucleation layer on Si(111) substrate is most proper about $260{\AA}$ to grow GaN in HVPE system. The surface morphology of GaN clearly shows the hexagonal crystallization. The XRD pattern showed strong peak at GaN{0001} direction.

Distinct properties of tungsten austenitic stainless alloy as a potential nuclear engineering material

  • Salama, E.;Eissa, M.M.;Tageldin, A.S.
    • Nuclear Engineering and Technology
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    • v.51 no.3
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    • pp.784-791
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    • 2019
  • In the present study, a series of tungsten austenitic stainless steel alloys have been developed by interchanging the molybdenum in standard SS316 by tungsten. This was done to minimize the long-life residual activation occurred in molybdenum and nickel after decommissioning of the power plant. The microstructure and mechanical properties of the prepared alloys are determined. For the sake of increasing multifunction property of such series of tungsten-based austenitic stainless steel alloys, gamma shielding properties were studied experimentally by means of NaI(Tl) detector and theoretically calculated by using the XCOM program. Moreover, fast neutrons macroscopic removal cross-section been calculated. The obtained combined mechanical, structural and shielding properties indicated that the modified austenitic stainless steel sample containing 1.79% tungsten and 0.64% molybdenum has preferable properties among all other investigated samples in comparison with the standard SS316. These properties nominate this new composition in several nuclear application domains such as, nuclear shielding domain.

Service Quality Dimensions of E-retailing of Islamic Banks and Its Impact on Customer Satisfaction: An Empirical Investigation of Kingdom of Saudi Arabia

  • TABASH, Mosab I.;ALBUGAMI, Moteb A.;SALIM, Mairaj;AKHTAR, Asif
    • The Journal of Asian Finance, Economics and Business
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    • v.6 no.3
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    • pp.225-234
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    • 2019
  • The study aims to explore key dimensions of service quality of E-Retailing of Islamic banks in the Kingdom of Saudi Arabia. The convenience sample size consists of 373 respondents who regularly use online Islamic banking facilities in Saudi Arabia was used. For measuring the consumers' perspective, a four-factor E-SERVQUAL scale; namely efficiency, system availability, fulfillment, and privacy was used. Exploratory Factor Analysis and Confirmatory Factor Analysis are used to test the model fitness. Structural equation modelling is utilized to determine the impact of E-service quality dimensions on customers' satisfaction. The results of the study reveal that 1) reliability as a dimension of E-retailing of Islamic banks made a significant impact on customers' overall satisfaction; 2) there is a positive significant relationship between responsiveness and customers' overall satisfaction. One unit increased in responsive leads to 0.763 unit increases in the overall satisfaction of the customer; and 3) ease of use is the most important dimensions of service quality of E-retailing of Islamic banks. One unit increases in Security/ Privacy leads to 0.473 unit increases in overall satisfaction. There is a positive impact of good E-service on customers' satisfaction, but it does not override unsatisfactory performance in other areas.

Synthesis and Quality of Cr-doped AIN Thin Films Grown by RF Sputtering

  • Quang, Pham Hong;Hung, Tran Quang;Dai, Ngo Xuan;Thanh, Tran Hoai;Kim, Cheol-Gi
    • Journal of Magnetics
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    • v.12 no.4
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    • pp.149-151
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    • 2007
  • The AlCrN films were grown by RF reactive sputtering method under the selected conditions. The Cr concentration was varied by the number of Cr pieces placed on the Al target. The sample quality has been studied by XRD, Auger spectroscopy, optical absorption and electrical resistant measurements. The XRD and Auger results show that the samples consist of a major phase with the $Al_{1-x}Cr_xN$ formula, which has a hexagonal structure, and a few percents at. of oxygen, which may form $Al_2O_3$. There exist the Cr clusters in the samples with high concentration of Cr. The optical absorption measurement provides the information about the band gap that relates strongly to the quality of samples. The quality of samples is also clearly reflected in electrical measurement, i.e., the temperature dependence of resistance exhibits a semiconductor characteristic only for the samples that have no Cr cluster. In these cases, the values of ionization energies $E_a$ can be derived from R(T) plots by using the function R(T) = Ro exp $(E_a/k_BT)$.

The Relationship Between Despotic Leadership and Employee Outcomes: An Empirical Study from Pakistan

  • KHAN, Hafiz Ghufran Ali;AHMED, Irshad;Ul AIN, Qurat;MUMTAZ, Roohi;IKRAM, Memoona
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.6
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    • pp.331-341
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    • 2022
  • Through emotional exhaustion, this study empirically tests followers' behavioral responses to autocratic leaders. The current research focuses on effects caused by despotic leadership on followers' emotional exhaustion, which leads to employee outcomes such as interpersonal deviances and indirect aggression. The association between despotic leadership and results (employee interpersonal deviance and indirect violence) is investigated in this study. In this study, emotional exhaustion is used as a mediator. Furthermore, negative affectivity is used as a moderator between despotic leadership and emotional exhaustion. A time-lagged framework is employed with a sample of 255 respondents. Age, qualification, marital status, gender, grade, type of organization, department, and job experience are among the eight demographical questions in this study. After evaluating the data for normality, correlation analysis was performed, followed by moderation and mediation analysis. The current study explores the link between despotic leadership and emotional exhaustion among followers, arguing that a despotic leader will leave followers exhausted at work. Emotional exhaustion was also linked to interpersonal deviances, such as indirect aggression, in a significant and positive way. Employee outcomes, such as interpersonal deviances and indirect aggressiveness through emotional exhaustion, will be influenced by a despotic leader, according to the findings.