Erbium nano particles (NPs) doped tellurite glasses were prepared via melt-quenched technique and their chemical composition are as follows; {[(TeO 2 ) 0.70 (B 2 O 3 ) 0.30 ] 0.7 (ZnO) 0.3 } y (Er 2 O 3 NPs) 1−y , y = 0.005, 0.01, 0.02, 0.03, 0.04 and 0.05. The amorphous state of the glass system was revealed and the  structural parameters indicating the formation of non-bridging  oxygen was shown. The current work underlines the spectral parameters from Judd–Ofelt (JO) studies, and upconversion spectra. The existence of erbium NPs was found experimentally using transmission electron microscopy (TEM). The Judd–Ofelt analysis suggests that the radiative probability, A rad is strong at ² H 11?2 —> ? I 15?2 and a longer lifetime at ? I 11?2 —> ? I 15?2 . The Argon laser beam was used to determine the upconversion emission peaks. The upconversion radiation emission excited at 800 nm was found in the range 390 nm.  ..

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We report on the optical efficiency of samarium nanoparticles (NPs) doped tellurite glasses experimentally, for the first time to the best of our knowledge. A high optical efficiency of samarium NPs doped tellurite glasses stable against crystallization was fabricated via melt- quenched technique. In particular, this work underlines the enhancement of optical properties with increasing samarium NPs concentration and the change of polarizability of tellurite glass network with the presence of samarium NPs. Using X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) analysis and transmission electron spectra (TEM), the amorphous arrangement, structural assignments and particle size had been revealed. The optical performance of samarium NPs doped tellurite glass was characterized by EL X-02C high accuracy ellipsometer and UV-Vis spectrophotometer. Based on ellipsometer and UV-Vis spectrophotometer, the refractive index was found slightly increases meanwhile the optical band .....

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In this work, the novel direct synthesis method of dimethylacetamide-based graphene oxide (GO) was performed through electrochemical exfoliation assisted by commercially available single-tail sodium dodecyl sulphate (SDS) surfactant. Then, the synthesised GO (SDS–GO) was incorporated into polyvinylidene fluoride (PVDF) solution to produce a nanofiltration (NF) membrane through the phase immersion method. The addition of GO into the preparation of membrane solution alters the membrane morphology and improves the hydrophilicity. TiO2 was also used as an additive for the NF membrane fabrication to further increase the membrane hydrophilicity. The fabricated PVDF/SDS–GO/TiO2 and PVDF/SDS– GO NF membranes were compared with pure PVDF membrane. Then, the fabricated NF membranes were tested for methylene blue (MB) rejection with 10 ppm MB concentration. On the basis of the dead end cell measurement operated at the pressure of 2 bar, the PVDF/SDS–GO/TiO2 presents high MB rejection (92......

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The use of erbium ions, Er3+ to enhance the dielectric properties is investigated in tellurite glass system for the frst time, tothe best of our knowledge. A glass series of tellurite glass with chemical composition, {[(TeO2)70(B2O3)30]70(ZnO)30}100−y(Er2O3)y (y = 0, 0.005, 0.01, 0.02, 0.03, 0.04 and 0.05) was fabricated via melt-quenched technique. The X-ray difraction and Fourier transform infrared spectroscopy analysis proved the amorphous structure and the formation of nonbridging oxygen in the glass system. The Er3+ ions afect greatly to the dielectric constant, ε′ in which the dielectric constant, ε′ show high value at a lower frequency and higher temperature (above 110 °C). The reduction of dielectric constant, ε′ is found with the increment value of frequency, which corresponds to the formation of the hindrance efect on heavy dipoles caused by the mixed transition-ion efect. Meanwhile, the dielectric constant, ε′ is enhanced with the increase of temperature. The .....

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A system of erbium oxide nanoparticles doped rice-husk-silicate borotellurite glasses with compositional formula, {[(TeO2)0.7 (B2O3)0.3]0.8 (SiO2)0.2}1−y (Er2O3 NPs)y with y = 0.01, 0.02, 0.03, 0.04 and 0.05 was fabricated using the method of melt-quenching. Various characterizations and measurement techniques such as density and molar volume, X-ray diffraction, Fourier transform infrared, transmission electron microscopy and UV–Vis spectroscopy were carried out to study the structural, morphological and optical properties of the fabricated glasses. The density values for the glasses increased from 4.1900 to 4.6003 g cm−3 with the addition of 1% to 5% of Er2O3 NPs in the glass structure. The increase can be ascribed to increase in the overall molar weight of the glass caused by the higher molecular weight of erbium. The microstructural nature revealed in the glass morphological evidence of nanoparticle agglomerations in the glasses. From the UV–Vis spectra both direct and i.....

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Kajian ini berbentuk analisis kandungan kualitatif bertujuan meneroka pandangan guru-guru mengenai masalahbuli dalam kalangan murid di sekolah. Respons bertulis daripada para peserta diperoleh melalui edaran set soalan berbentuk umum dan terbuka yang dihantar menggunakan mel elektronik. Penganalisisan data pula dibuat secara induktif untuk mengenal pasti kategori-kategori dan tema-tema yang terkandung dalam bahan kajian. Dapatan kajian menunjukkan bahawa terdapat sepuluh tema merangkumi definisi, lokasi, murid yang terlibat, punca, dan keseriusan masalah buli. Selain itu, didapati majoriti guru kurang jelas tentang definisi buli. Namun begitu, mereka beranggapan bahawa masalah buli dalam kalangan murid adalah serius dan perlu dibanteras dengan segera. Memandangkan dapatan hanya terhad kepada perbincangan tema dan kategori, maka dicadangkan agar kajian lanjutan, khususnya kajian berbentuk grounded theory dijalankan. Kajian sebegini membolehkan pengkaji meneroka pengalaman guru dengan le.....

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New glass samples with composition (1 – x)[(TeO2)70(B2O3)30] – x(Gd2O3) with x = 0.2, 0.4, 0.6, 0.8 and 1.0 in mol% have been synthesized by conventional melt-quenching techniques. X-ray diffraction (XRD) studies were performed in order to confirm the amorphous nature of the samples. The density of the samples has been found to vary with the Gd2O3 content, whereas an opposite trend has been observed in the molar volume. The analysis of Fourier Transform Infrared (FT-IR) spectroscopy of the samples showed that the glass network is mainly built of TeO3, TeO4, BO3 and BO4 units. The addition of Gd2O3 changed the refractive index, optical band gap and Urbach energy of the glass samples. The thermal properties of the studied glasses were investigated by measuring the thermal diffusivity of the samples by using photoflash method at room temperature..

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This research intended to investigate and assess the leadership practices amongst headmasters of C accredited primary schools in the region of Paser, Indonesia. The qualitative research approach was employed in the form of a case study research design. The respondent selection was carried out through the purposive sampling method resulting in the choosing of three primary school headmasters from the region of Paser, Indonesia. The instruments utilized for data collection purposes comprised of interview, observation and document analysis. Research result demonstrated that the three headmasters as school leaders practiced several of the traits proposed in the instructional leadership and leadership strategies theories. The elements that were observed practiced by the headmasters include planning and disseminating school goals, planning teaching management programmes, supervising and assessing teaching programmes, monitoring students’ progress, controlling study period, encouraging prof.....

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Kajian ini adalah bertujuan untuk menerangkan hubungan antara ciri-ciri kerja berpasukan dengan keberkesanan kerja berpasukan dalam kalangan guru-guru Tingkatan Enam Sekolah Menengah Kebangsaan di Negeri Pahang. Kajian ini adalah berbentuk kuantitatif melibatkan pengumpulan data yang dilakukan menggunakan soal selidik. Populasi kajian adalah seramai 677 orang. Sampel kajian melibatkan 250 orang guru Tingkatan Enam Sekolah Menengah Kebangsaan di Negeri Pahang. Statistik deskriptif digunakan bagi menjawab persoalan kajian manakala statistik inferensi iaitu analisis Korelasi Pearson untuk menguji hipotesis. Dapatan kajian menunjukkan daripada analisis Korelasi Pearson, bagi aspek dibawah tema proses, analisis menunjukkan aspek potensi, perkongsian beban tugas dan komunikasi/kerjasama di dalam pasukan kerja menunjukkan hubungan yang tinggi dengan keberkesanan pasukan kerja. Bagi aspek di bawah tema reka bentuk tugas, aspek pelbagai tugas dan penglibatan menunjukkan hubungan yang tinggi den.....

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Mobile Multihop Relay (MMR) network is an attractive and low-cost solution for expanding service coverage and enhancing throughput of the conventional single hop network. However, mobility of Mobile Station (MS) in MMR network might lead to performance degradation in terms of Quality of Service (QoS). Selecting an appropriate Relay Station (RS) that can support data transmission for high mobility MS to enhance QoS is one of the challenges in MMR network. The main goal of the work is to develop and enhance relay selection mechanisms that can assure continuous connectivity while ensuring QoS in MMR networkusing NCTUns simulation tools. The approach is to develop and enhance a relay selection for MS with continuous connectivity in non-transparent relay. In this approach, the standard network entry procedure is modified to allow continuous connectivity with reduced signaling messages whenever MS joins RS that is out of Multihop Relay Base Station (MRBS) coverage and the relay selection is .....

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