Effectiveness of Educational Supervision in Sultanate of Oman as Perceived by Teachers

The study aimed at identifying the effectiveness of educational supervision in public schools in the Sultanate of Oman. To achieve the aim of the study, a questionnaire was designed. It consisted of 49 items distributed into five domains. The domains are: enhancement of instructional and learning processes; school's activities and media; implementation, assessment, and development of curriculum; assessment of instructional and learning process; and teachers’ professional development. The validity and reliability of the questionnaire were examined. The sample of the study consisted of 592 male and female teachers. The results showed that educational supervision in Oman had high effectiveness on enhancement of instructional and learning processes, school's activities and media, whereas, it had medium effectiveness on the other three domains. Based on the results, few recommendations have been suggested

Synthesis, optical spectroscopy, structural, and DFT studies on dimeric iodo-bridged Copper(I)complexes

Three new iodo-bridged copper(I)complexes of the type [CuI(PPh 3 )L] 2 , where L = Ar–≡–C 5 H 4 N, Ar = phenyl (C 1 ), biphenyl (C 2 )and flourenyl (C 3 )have been synthesized via coordination-driven self-assembly processes. Two of Cu(I)complexes, C 2 and C 3 , have been characterized by single-crystal X-ray diffraction studies. The complexes have two molecules of the P-donor ligand and two molecules of the N-donor ligand in trans configurations, supporting the central Cu 2 I 2 unit. Absorption properties of the complexes have been investigated. Extensive DFT calculation has been carried out to delineate the influence of aromatic spacers on the optical properties and the nature of excited states. The ease of synthesis of these Cu(I)dimers and the wide range of ethynylpyridine supporting ligands that can be incorporated highlights the potential for these materials to form polymers by linking through the ethylylpyridine ligands. </p

Breast cancer image classification using pattern-based Hyper Conceptual Sampling method

The increase in biomedical data has given rise to the need for developing data sampling techniques. With the emergence of big data and the rise of popularity of data science, sampling or reduction techniques have been assistive to significantly hasten the data analytics process. Intuitively, without sampling techniques, it would be difficult to efficiently extract useful patterns from a large dataset. However, by using sampling techniques, data analysis can effectively be performed on huge datasets, to produce a relatively small portion of data, which extracts the most representative objects from the original dataset. However, to reach effective conclusions and predictions, the samples should preserve the data behavior. In this paper, we propose a unique data sampling technique which exploits the notion of formal concept analysis. Machine learning experiments are performed on the resulting sample to evaluate quality, and the performance of our method is compared with another sampling technique proposed in the literature. The results demonstrate the effectiveness and competitiveness of the proposed approach in terms of sample size and quality, as determined by accuracy and the F1-measure. 2018This contribution was made possible by NPRP-07-794-1-145 grant from the Qatar National Research Fund (a member of Qatar foundation). The statements made herein are solely the responsibility of the authors.Scopu

Salts of Lanthanide(III) Hexafluoroacetylacetonates [Ln = Sm(III), Eu(III) and Tb(III)] with Dipyridylammonium Cations: Synthesis, Characterization, Photophysical Properties and OLED Fabrication

A series of tetrakis lanthanide complexes with the general formula [Ln(hfaa) 4] -(DpaH) + [Ln = (Sm-1), (Eu-1) and (Tb-1)], hfaa = hexafluroacetylacetonate and Dpa −2,2′-dipyridylamine] has been synthesized by the reaction of LnCl 3, hfaa and Dpa in the presence of ammonia solution (25%). The complexes have been characterized by analytical and spectroscopic methods. The solution molecular structure of the complexes was elucidated by one- and two-dimensional NMR spectroscopy which shows that the DpaH + cation retains a close interaction with the lanthanide anion in solution. The crystal structure of Eu-1, determined by single crystal X-ray diffraction, confirms this intermolecular interaction in the solid-state through a N–H⋯O hydrogen bond of 2.187 Å. In the [Eu(hfaa) 4] - anion the EuO 8 coordination polyhedron has a distorted triangular dodecahedron geometry with approximate D 2d-symmetry around the metal centre. Photophysical, thermal, and electroluminescent properties of the complexes have been investigated. The Sm-1 and Eu-1 complexes displayed efficient typical red emission with a sizeable photoluminescence quantum yield (PLQY) while Tb-1 displayed near-white light emission. The complexes have been used as dopants to fabricate single- and double-emitting layer (EML) OLEDs through the thermal evaporation method. At the optimum doping concentration, double-EML Eu-1 based device displayed orange electroluminescence (EL) with a brightness (B) of 417 cd/m 2 and very low V turn-on = 3.4 V. Interestingly, the Sm-1 based single-EML device exhibited pure red emission with the Commission internationale de l'éclairage [(CIE) x,y = 0.613, 0.321], which is rare. The Sm-1 based device performance [B = 145 cd/m 2, current efficiency (η c) = 0.35 cd/A, power efficiency (η p) = 0.15 lm/W with an external quantum efficiency (EQE) = 0.3% and V turn-on = 7.1 V] surpassed that of the only reported Sm-based single red-OLED (R-OLED). </p

Single component white-OLEDs derived from tris(β-diketonato) europium(iii) complexes bearing the large bite angle N^N 2-(4-thiazolyl)benzimidazole ligand

Two new organo-europium complexes (OEuCs) [Eu(tfac)3(TB-Im)] (Eu1) [Eu(hfac)3(TB-Im)] (Eu2) incorporating fluorinated (hexafluoroacetylacetone; Hhfaa) or hemi-fluorinated (trifluoroacetylacetone; Htfac) β-diketones together with the large bite angle N^N ligand (2-(4-thiazolyl)benzimidazole; TB-Im) have been synthesized and characterized. The structure of the complexes has been established by single crystal X-ray diffraction (SC-XRD) analysis and shows that the coordination sphere is composed of a EuO6N2 core (octacoordinated). Continuous shape measures (CShMs) revealed that the geometry around Eu(III) is trigonal dodecahedral with approximate D2d-symmetry. Efficient red emission is observed for both the complexes in solution with a fairly large photoluminescence quantum yield (PLQY (QLEu) = 39.00–47.00%). Furthermore, by utilizing the experimental photoluminescence (PL) data and theoretical modelling employing density functional theory (DFT) in conjunction with LUMPAC, energy transfer (ET) and back energy transfer rates were calculated, and an ET mechanism for the sensitized PL is proposed and discussed in detail. Finally, the complexes were used as an emitting layer (EML) to fabricate 20 organic light emitting diodes (OLEDs) by varying the doping concentration. Interestingly, both the complex-based OLEDs at 4 wt% doping concentration display white electroluminescence (EL) with the brightness (B) = 100.5–364.1 cd m−2 at very low turn-on voltage (Vturn-on) = 3.9–4.6 V. The overall electroluminescence performance of Eu1 and Eu2 is higher than that of the reported europium based single component white-OLEDs

Dicopper(I) Complexes Incorporating Acetylide-functionalized Pyridinyl-based Ligands::Synthesis, Structural and Photovoltaic Studies

Heteroaryl incorporated acetylide-functionalized pyridinyl ligands (<b>L1–L6</b>) with the general formula Py-CC-Ar (Py = pyridine and Ar = <i>thiophene-2-yl</i>, 2,2′<i>-bithiophene]-5-yl</i>, 2,2′<i>:5</i>′,2″<i>-terthiophene]-5-yl</i>, <i>thieno­[2,3-<i>b</i>]­thiophen-2-yl</i>, <i>quinoline-5-yl</i>, <i>benzo­[c]­[1,2,5]­thiadiazole-5-yl</i>) have been synthesized by Pd(0)/Cu­(I)-catalyzed cross-coupling reaction of 4-ethynylpyridine and the respective heteroaryl halide. Ligands <b>L1–L6</b> were isolated in respectable yields and characterized by microanalysis, IR spectroscopy, ¹H NMR spectroscopy, and ESI-MS mass spectrometry. A series of dinuclear Cu­(I) complexes <b>1</b>–<b>10</b> have been synthesized by reacting <b>L1–L6</b> with CuI and triphenylphosphine (PPh₃) (<b>R1</b>) or with an anchored phosphine derivative, 4-(diphenylphosphino) benzoic acid (<b>R2</b>)/2-(diphenylphosphino)­benzenesulfonic acid (<b>R3</b>), in a stoichiometric ratio. The complexes are soluble in common organic solvents and have been characterized by analytical, spectroscopic, and computational methods. Single-crystal X-ray structure analysis confirmed rhomboid dimeric structures for complexes <b>1</b>, <b>2</b>, <b>4</b>, and <b>5</b>, and a polymeric structure for <b>6</b>. Complexes <b>1</b>–<b>6</b> showed oxidation potential responses close to 0.9 V vs Fc^0/+, which were chemically irreversible and are likely to be associated with multiple steps and core oxidation. Preliminary photovoltaic (PV) results of these new materials indicated moderate power conversion efficiency (PCE) in the range of 0.15–1.56% in dye-sensitized solar cells (DSSCs). The highest PCE was achieved with complex <b>10</b> bearing the sulfonic acid anchoring functionality

Dioxygen Binding by Cobalt(II) Complexes of 8,8'-bis(aminomethyl)-2,2'-biquinoline

A new series of Co(II) complexes of the type CoLX2 , where Lis a tetra-dentate ligand 8,8'-bis(aminomethyl)-2,2'-biquinoline  and X= SCN–, BF4–, I– or NO3– ,  have been synthesized and characterized. The complexes have magnetic moments in the range typical of a low-spin d7 Co(II) center. The interaction of these Co(II) complexes with dioxygen was studied by E.S.R. spectroscopy. A dicobalt(III) peroxo-bridged complex was formed in DMF solution, associated with the formation of an E.S.R.-silent solution compatible with the formation of low-spin d6 Co(III) species. Similar behavior was also observed for the interaction of these Co(II) complexes with dioxygen in the presence of ancillary ligands such as pyridine and 2-methylimidazole. The dioxygen complexes proved successful as oxygen carrier oxidation catalysts for tripehnylphosphine and 2,6-bis(t-butyl)phenol

Effectiveness of Educational Supervision in Sultanate of Oman as Perceived by Teachers

The study aimed at identifying the effectiveness of educational supervision in public schools in the Sultanate of Oman. To achieve the aim of the study, a questionnaire was designed. It consisted of 49 items distributed into five domains. The domains are: enhancement of instructional and learning processes; school's activities and media; implementation, assessment, and development of curriculum; assessment of instructional and learning process; and teachers’ professional development. The validity and reliability of the questionnaire were examined. The sample of the study consisted of 592 male and female teachers. The results showed that educational supervision in Oman had high effectiveness on enhancement of instructional and learning processes, school's activities and media, whereas, it had medium effectiveness on the other three domains. Based on the results, few recommendations have been suggested.

Synthesis, optical spectroscopy, structural, and DFT studies on dimeric iodo-bridged Copper(I)complexes

Three new iodo-bridged copper(I)complexes of the type [CuI(PPh 3 )L] 2 , where L = Ar–≡–C 5 H 4 N, Ar = phenyl (C 1 ), biphenyl (C 2 )and flourenyl (C 3 )have been synthesized via coordination-driven self-assembly processes. Two of Cu(I)complexes, C 2 and C 3 , have been characterized by single-crystal X-ray diffraction studies. The complexes have two molecules of the P-donor ligand and two molecules of the N-donor ligand in trans configurations, supporting the central Cu 2 I 2 unit. Absorption properties of the complexes have been investigated. Extensive DFT calculation has been carried out to delineate the influence of aromatic spacers on the optical properties and the nature of excited states. The ease of synthesis of these Cu(I)dimers and the wide range of ethynylpyridine supporting ligands that can be incorporated highlights the potential for these materials to form polymers by linking through the ethylylpyridine ligands. </p