Eu³⁺ doped lutetium molybdenum oxides: Synthesis, optical properties, thermal behavior, and LED packaging

Cao, Chunyan,Xie, Along,Zhou, Tianliang,Zhong, Haichang,Lu, Xiangjun,Xie, An,Noh, Hyeon Mi,Jeong, Jung Hyun Elsevier 2020 Journal of luminescence Vol.217 No.-

<P><B>Abstract</B></P> <P>Some lutetium molybdenum oxides were synthesized through a solid-state reaction method. By adjusting the molar ratios of raw materials of Lu<SUB>2</SUB>O<SUB>3</SUB> (Eu<SUB>2</SUB>O<SUB>3</SUB>) to MoO<SUB>3</SUB>, Eu<SUP>3+</SUP> doped lutetium molybdenum oxides Lu<SUB>2</SUB>MoO<SUB>6</SUB>, Lu<SUB>2</SUB>Mo<SUB>2</SUB>O<SUB>9</SUB>, Lu<SUB>2</SUB>(MoO<SUB>4</SUB>)<SUB>3</SUB>, and Lu<SUB>6</SUB>MoO<SUB>12</SUB> were obtained. The materials were characterized by X-ray diffraction (XRD) patterns, scanning electron microscope (SEM) images, energy-dispersive spectra (EDS), diffuse reflection (DR) spectra, photoluminescence (PL) excitation and emission spectra, luminescence decay curves, and temperature dependent integrated emission spectra. Enhanced excitation and emission spectra were recorded at high temperatures. Possible energy transfer processes were proposed to explain the excitation and emission spectra. By combining some phosphors with near ultraviolet (NUV) chips, the obtained light emitting diodes (LEDs) gave red light under forward bias current. The results suggest that the obtained Eu<SUP>3+</SUP> doped lutetium molybdenum oxides have potential applications in phosphor converted based NUV LEDs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Eu<SUP>3+</SUP> doped Lu<SUB>2</SUB>MoO<SUB>6</SUB>, Lu<SUB>2</SUB>Mo<SUB>2</SUB>O<SUB>9</SUB>, Lu<SUB>2</SUB>(MoO<SUB>4</SUB>)<SUB>3</SUB>, and Lu<SUB>6</SUB>MoO<SUB>12</SUB> were obtained. </LI> <LI> The materials present different structures, morphologies, optical properties, and luminescece decay behaviors. </LI> <LI> Eu<SUP>3+</SUP> concentration dependent optical properties in Lu<SUB>2</SUB>MoO<SUB>6</SUB> were researched. </LI> <LI> Enhanced excitation and emission spectra were recorded under high temperatures in some materials. </LI> <LI> Red LEDs were obtained by packaging phosphors to NUV LED chips. </LI> </UL> </P>

The Observation of Children`s Holding Position to Redesign Elementary School Chair for Easy Carrying and Moving

( Lu`lu` Purwaningrum ),( Satoshi Muraki ) 한국감성과학회 2014 춘계학술대회 Vol.2014 No.-

Objectives. Carrying and moving chairs enable and improve learning activities at school, which leads to better quality of education. At elementary schools in Indonesia and other developing countries, only one size of chair has been used for all ages and grades, therefore, making it heavy for younger children. The objective of the present study was to observe the motion of carrying and moving an elementary school chair by children. Methods. A total of 41 children consisting of 16 Indonesian and 25 Japanese children (17 boys and 24 girls) aged 6, 7, 8 and 9 participated in this study. We used three elementary school chairs (1 Indonesian and 2 Japanese chairs). The participants carried and moved the chairs 3 m with an ordinary speed, and were allowed to hold any part of the chair that was convenient for them. We recorded their motion when carrying and moving the chair. Results. The chair was carried at the side or in front of the child`s body, and the chair being in a lateral position is the most popular method of carrying and moving (75%).

The observation of children`s holding position to redesign elementary school chair for easy carrying and moving

Lu’lu’ Purwaningrum,Satoshi Muraki 대한인간공학회 2014 대한인간공학회 학술대회논문집 Vol.2014 No.5

Objectives. Carrying and moving chairs enable and improve learning activities at school, which leads to better quality of education. At elementary schools in Indonesia and other developing countries, only one size of chair has been used for all ages and grades, therefore, making it heavy for younger children. The objective of the present study was to observe the motion of carrying and moving an elementary school chair by children. Methods. A total of 41 children consisting of 16 Indonesian and 25 Japanese children (17 boys and 24 girls) aged 6, 7, 8 and 9 participated in this study. We used three elementary school chairs (1 Indonesian and 2 Japanese chairs). The participants carried and moved the chairs 3 m with an ordinary speed, and were allowed to hold any part of the chair that was convenient for them. We recorded their motion when carrying and moving the chair. Results. The chair was carried at the side or in front of the child’s body, and the chair being in a lateral position is the most popular method of carrying and moving (75%). In all methods, participants showed a preference in using two particular chair parts to hold the chair. Conclusions. Careful consideration is needed on the design of elementary school chairs from the perspective of the main methods and holding pattern for carrying and moving them, especially heavy chairs that are used in elementary schools in Indonesia.

Preventive Effects of Intracisternal Alphatochopherol on Cerebral Vasospasm in Experimental Subarachnoid Hamorrhage

SerdarKemalo?lu,Umit?zkan,FahriYilmaz,ErdemAK,HamitAcemo?lu,G?n?l?lmez,Ramazan?ım?ek,AbdurrahmanBakir 연세대학교의과대학 2003 Yonsei medical journal Vol.44 No.6

Effects of α-Si₃N₄ seeds and sintering additives on properties of porous silicon nitride ceramics fabricated by carbothermal reduction

Yuan Lu,Ji-Qiang Gao,Jian-feng Yang 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.6

In this paper, porous Si3N4 ceramics were fabricated by carbothermal reduction between silicon dioxide and carbon [1]. The influences of α-Si3N4 seeds and sintering additives on the microstructure and mechanical properties of porous Si3N4 ceremics were investigated. XRD analysis proved the complete formation of a single-phase β-Si3N4. SEM analysis showed that the resultant porous Si3N4 ceramics had a fine microstructure and a uniform pore structure. The sintered sample with Lu2O3 as sintering additive showed finer, higher aspect ratio β-Si3N4 grains. The addition of Eu2O3 accelerated the densification of porous Si3N4 ceramics, decreased the porosity and increased the flexural strength. The addition of α-Si3N4 seeds accelerated the formation of the α-Si3N4 phase at a low temperature and the α-β phase transformation process at a high temperature. With an increase in the α-Si3N4 seeds content, the porosity decreased, and the flexural strength increased accordingly. In this paper, porous Si3N4 ceramics were fabricated by carbothermal reduction between silicon dioxide and carbon [1]. The influences of α-Si3N4 seeds and sintering additives on the microstructure and mechanical properties of porous Si3N4 ceremics were investigated. XRD analysis proved the complete formation of a single-phase β-Si3N4. SEM analysis showed that the resultant porous Si3N4 ceramics had a fine microstructure and a uniform pore structure. The sintered sample with Lu2O3 as sintering additive showed finer, higher aspect ratio β-Si3N4 grains. The addition of Eu2O3 accelerated the densification of porous Si3N4 ceramics, decreased the porosity and increased the flexural strength. The addition of α-Si3N4 seeds accelerated the formation of the α-Si3N4 phase at a low temperature and the α-β phase transformation process at a high temperature. With an increase in the α-Si3N4 seeds content, the porosity decreased, and the flexural strength increased accordingly.

The Influence of Cigarette Smoke on the Epithelium of the Vestibule: an Electron Microscopic Study

Mukaddes E?refo?lu,Erol Selimo?lu,Muammer E?refo?lu,?zgen Vuraler 연세대학교의과대학 2003 Yonsei medical journal Vol.44 No.4

It is known that cigarette smoke induces cytological alterations on the respiratory and olfactory mucosa of the nasal cavity. We evaluated whether cigarette smoking had adverse effects on the epithelium of the vestibule, in the absence of any published ultrasutructural studies. We evaluated ten patients suffering from septum deviation, eight of whom were long-term smokers. While each layer of the epithelium obtained from the non-smokers consisted of a homogeneous cell population, each from the long-term smokers consisted of a heterogeneous cell population. The most prominent changes occurred in the shape and size of the cells and nuclei, the number and length of the cytoplasmic projections, the number and distribution pattern of the desmosomes, and the width of the intercellular spaces. We concluded that cigarette smoke produces hyperplastic and dysplastic changes, important factors related with cancer development, on the epithelium of the vestibule.

Prestressed concrete beams under torsion-extension of the VATM and evaluation of constitutive relationships

Luís F.A. Bernardo,Jorge M.A. Andrade 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.61 No.5

A computing procedure is presented to predict the ultimate behavior of prestressed beams under torsion. This computing procedure is based on an extension of the Variable Angle Truss-Model (VATM) to cover both longitudinal and transversal prestressed beams. Several constitutive relationships are tested to model the behavior of the concrete in compression in the struts and the behavior of the reinforcement in tension (both ordinary and prestress). The theoretical predictions of the maximum torque and corresponding twist are compared with some results from reported tests and with the predictions obtained from some codes of practice. One of the tested combinations of the relationships for the materials was found to give simultaneously the best predictions for the resistance torque and the corresponding twist of prestressed beams under torsion. When compared with the predictions from some codes of practice, the theoretical model which incorporates the referred combination of the relationships provides best values for the torsional strength and leads to more optimized designs.

Pseudocholangiocarcinoma Sign: Management of Portal Cavernoma Biliopathy with Fully-Covered Self-Expandable Metal Stent

Luís C Lourenço,David V Horta,Catarina G Rodrigues,Jorge Canena,Jorge Reis 대한소화기내시경학회 2017 Clinical Endoscopy Vol.50 No.3

Brief report

An Overview on Cardamonin

Luís Moreira Gonçalves,Inês Maria Valente,José António Rodrigues 한국식품영양과학회 2014 Journal of medicinal food Vol.17 No.6

Cardamonin, as shown by the increasing number of publications, has received growing attention from the scientific community due to the expectations toward its benefits to human health. In this study, research on cardamonin is reviewed, including its natural sources, health promoting aspects, and analytical methods for its determination. Therefore, this article hopes to aid current and future researchers on the search for reliable answers concerning cardamonin’s value in medicine.

Litigation in Vietnamese Criminal Procedure and the Judicial Reform

Lu’o’ng Thi My Quỳnh 전남대학교 법학연구소 2014 법학논총 Vol.34 No.1

Vietnam is actively implementing judicial reform strategy to 2020. To fit the generaltrend of the world integration, including orientation to complement the legal system,one of the priorities of judicial reform in Vietnam is: “Improving the quality of theprosecutors at trial, guaranteeing democratic litigation with lawyer, defense counsel andpeople involving in the proceedings…. The judgment of the Court must be basedprimarily on the results of litigation at the trial…”. By pointing out and analyzingspecific rules of Vietnam Criminal Procedure law, the author made comments andreviews on the role of litigation in Vietnam criminal proceedings in the context ofimplementing the judicial reform strategy.