150 research outputs found
The interagency relationship between the personnel department and the organization & management unit in the Arab Republic of Egypt
The development of the personal department in the Arab of Egypt is slow
Effective Learning Outcomes Assessment: The Case of the MIS Department at the UoS
Accrediting organizations now mandate the development of learning outcomes (LO) and the methods to assess those learning outcomes for national and international institutions of higher learning. Because of this, academic institutions pay greater attention to the development and assessment of these LO. There are two types of learning outcomes: course outcomes and program outcomes. This paper presents an empirical study that examines both kinds of LO in a case study of one course (title: Database Fundamental and Applications, number: 0303331) within the Management Information System (MIS) department at the University of Sharjah (UoS), United Arab Emirates and presents the following with regard to this case study: 1) the development process of the LO for this specific course; 2) the data collection process, and 3) the data collected related to the assessment instruments for both the course and program LO (course learning instructions, course exams, course projects, students’ records, students’ grades, course reports, course evaluation, instructor evaluation, exit surveys, employer surveys, and job placement indicators); 4) the methods of assessment of the LO based on the analysis of the collected data using a variety of analysis technique and tools; and 5) the usage of the analysis results in successive semesters in order to improve the MIS courses and program. The findings of this empirical study suggest several areas for improvement. One improvement is the addition of more practice-based learning components. Additionally, the study shows that the enhancement of the course material, the improvement of teaching strategies, and the usage of technology and its infusion into the learning process are areas that can improve LO. Overall, the method of LO development and assessment described in this empirical examination has shown a positive effect on the courses and program in the MIS department, and it is believed that the results can be generalized for use by others in developing and assessing LO in other learning institutions
Gated Ensemble of Spatio-temporal Mixture of Experts for Multi-task Learning in Ride-hailing System
Designing spatio-temporal forecasting models separately in a task-wise and
city-wise manner poses a burden for the expanding transportation network
companies. Therefore, a multi-task learning architecture is proposed in this
study by developing gated ensemble of spatio-temporal mixture of experts
network (GESME-Net) with convolutional recurrent neural network (CRNN),
convolutional neural network (CNN), and recurrent neural network (RNN) for
simultaneously forecasting spatio-temporal tasks in a city as well as across
different cities. Furthermore, a task adaptation layer is integrated with the
architecture for learning joint representation in multi-task learning and
revealing the contribution of the input features utilized in prediction. The
proposed architecture is tested with data from Didi Chuxing for: (i)
simultaneously forecasting demand and supply-demand gap in Beijing, and (ii)
simultaneously forecasting demand across Chengdu and Xian. In both scenarios,
models from our proposed architecture outperformed the single-task and
multi-task deep learning benchmarks and ensemble-based machine learning
algorithms.Comment: arXiv admin note: text overlap with arXiv:2012.0886
Unconventional hydrogen bonding to organic ions in the gas phase: Stepwise association of hydrogen cyanide with the pyridine and pyrimidine radical cations and protonated pyridine
Equilibrium thermochemical measurements using the ion mobility drift cell technique have been utilized to investigate the binding energies and entropy changes for the stepwise association of HCN molecules with the pyridine and pyrimidine radical cations forming the C5H5N+· (HCN)nand C4H4N2 +· (HCN)n clusters, respectively, with n = 1–4. For comparison, the binding of 1–4 HCN molecules to the protonated pyridine C5H5NH+(HCN)n has also been investigated. The binding energies of HCN to the pyridine and pyrimidine radical cations are nearly equal (11.4 and 12.0 kcal/mol, respectively) but weaker than the HCN binding to the protonated pyridine (14.0 kcal/mol). The pyridine and pyrimidine radical cations form unconventional carbon-based ionic hydrogen bonds with HCN (CHδ+⋯NCH). Protonated pyridine forms a stronger ionichydrogen bond with HCN (NH+⋯NCH) which can be extended to a linear chain with the clustering of additional HCN molecules (NH+⋯NCH··NCH⋯NCH) leading to a rapid decrease in the bond strength as the length of the chain increases. The lowest energy structures of the pyridine and pyrimidine radical cation clusters containing 3-4 HCN molecules show a strong tendency for the internal solvation of the radical cation by the HCN molecules where bifurcatedstructures involving multiple hydrogen bonding sites with the ring hydrogen atoms are formed. The unconventional H-bonds (CHδ+⋯NCH) formed between the pyridine or the pyrimidine radical cations and HCN molecules (11–12 kcal/mol) are stronger than the similar (CHδ+⋯NCH)bonds formed between the benzene radical cation and HCN molecules (9 kcal/mol) indicating that the CHδ+ centers in the pyridine and pyrimidine radical cations have more effective charges than in the benzene radical cation
Pyran-Squaraine as Photosensitizers for Dye-Sensitized Solar Cells: DFT/TDDFT Study of the Electronic Structures and Absorption Properties
In an effort to provide, assess, and evaluate a theoretical approach which enables designing efficient donor-acceptor dye systems, the electronic structure and optical properties of pyran-squaraine as donor-acceptor dyes used in dye-sensitized solar cells were investigated. Ground state properties have been computed at the B3LYP/6-31+G** level of theory. The long-range corrected density functionals CAM-B3LYP, PBEPBE, PBE1PBE (PBE0), and TPSSH with 6-311++G** were employed to examine absorption properties of the studied dyes. In an extensive comparison between experimental results and ab initio benchmark calculations, the TPSSH functional with 6-311++G** basis set was found to be the most appropriate in describing the electronic properties for the studied pyran and squaraine dyes. Natural transition orbitals (NTO), frontier molecular orbitals (FMO), LUMO, HOMO, and energy gaps, of these dyes, have been analyzed to show their effect on the process of electron injection and dye regeneration. Interaction between HOMO and LUMO of pyran and squaraine dyes was investigated to understand the recombination process and charge-transfer process involving these dyes. Additionally, we performed natural bond orbital (NBO) analysis to investigate the role of charge delocalization and hyperconjugative interactions in the stability of the molecule
Hydration of the pyrimidine radical cation and stepwise solvation of protonated pyrimidine with water, methanol, and acetonitrile
Equilibrium thermochemical measurements using an ion mobility drift cell technique have been utilized to investigate the binding energies and entropy changes associated with the stepwise hydration of the biologically significant ions pyrimidine radical cation and protonated pyrimidine. The binding energy of the hydrated pyrimidine radical cation is weaker than that of the proton-bound dimer pyrimidineH+(H2O) consistent with the formation of a weak carbon-based CHδ+··OH2 hydrogen bond (11.9 kcal/mol) and a stronger NH+··OH2 hydrogen bond (15.6 kcal/mol), respectively. Other proton-bound dimers such as pyrimidineH+(CH3OH) and pyrimidineH+(CH3CN) exhibit higher binding energies (18.2 kcal/mol and 22.8 kcal/mol, respectively) due to the higher proton affinities and dipole moments of acetonitrile and methanol as compared towater. The measured collisional cross sections of the proton-bound dimers provide experimental-based support for the DFT calculated structures at the M06-2x/6-311++G (d,p) level. The calculations show that the hydrated pyrimidine radical cation clusters form internally solvated structures in which the water molecules are bonded to the C4N2H4 •+ ion by weak CHδ+··OH2 hydrogen bonds. The hydrated protonated pyrimidine clusters form externally solvatedstructures where the water molecules are bonded to each other and the ion is external to thewater cluster. Dissociative proton transfer reactions C4N2H4 •+(H2O)n−1 + H2O → C4N2H3 • + (H2O)nH+ and C4N2H5 +(H2O)n−1 + H2O → C4N2H4 + (H2O)nH+ are observed for n ≥ 4 where the reactions become thermoneutral or exothermic. The absence of the dissociative proton transfer reaction within the C4N2H5 +(CH3CN)n clusters results from the inability of acetonitrile molecules to form extended hydrogen bonding structures such as those formed by water and methanol due to the presence of the methyl groups which block the extension of hydrogen bonding networks
Protease activity of some mesophilic streptomycetes isolated from Egyptian habitats
Different streptomycetes (317 isolates) were obtained from several
sources and areas in Egypt and were screened for proteolytic activity.
Thirty nine of them produced proteases and were subjected to
identification. Streptomyces anulatus formed the most abundant portion
of the isolates. This species deserves special attention because it is
a good candidate for biotechnological applications
TAXONOMICAL STUDIES ON CERTAIN STREPTOMYCETES EXHIBITING ANTIMICROBIAL ACTIVITY ISOLATED FROM EGYPTIAN SOILS
The easy access and appropriate use of antimicrobials led to selection
and spread of resistant microorganisms strains. It is imperative to
search and screen for new and more effective antimicrobials from
microorganisms found in the environment. The objective of this work is
to isolate streptomycetes from soil of Kalubiya Governorate in order to
screen them for antimicrobial activity against reference Gram-positive,
Gram-negative bacteria as well as unicellular and filamentous fungi. A
total of 500 strains of streptomycetes were isolated. Sixty strains (12
%) showed antimicrobial activity. The morphological, cultural,
physiological and biochemical characters were studied for
identification of the isolates at species level. The obtain-ed results
revealed that the dominant group was Streptomyces lydicus
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