Electrically Insulative Performances of Ceramic and Clay Films Deposited via Supersonic Spraying

Lee, J. G.,Kim, D. Y.,Joshi, B. N.,Lee, J. H.,Lee, T. K.,Kim, J. s.,Yang, D. h.,Kim, W. Y.,Al-Deyab, S. S.,Yoon, S. S. Springer Science + Business Media 2016 Journal of thermal spray technology Vol.25 No.4

<P>Supersonic spray coating techniques were applied to deposit ceramic and clay particles as films for use in electrical insulation. TiO2 and Al2O3 ceramics were aerosol-deposited under vacuum while kaolinite, montmorillonite, and bentonite clays were deposited by cold spraying in open air. The electrical resistivity of Al2O3 and TiO2 were similar to 10(9) and similar to 10(8) Omega cm, respectively. The resistivity of kaolinite and montmorillonite were similar to 10(12) Omega cm. Bentonite showed the lowest electrical resistivity of similar to 10(9) Omega cm among the clays because of the high cation exchange capacity of the material. The film surface morphologies and mechanical properties in the form of hardness and scratchability were also investigated.</P>

Factor Structure, Validity and Reliability of The Teacher Satisfaction Scale (TSS) In Distance-Learning During Covid-19 Crisis: Invariance Across Some Teachers' Characteristics

Almaleki, Deyab A.,Bushnaq, Afrah A.,Altayyari, Basmah A.,Alshumrani, Amenah N.,Aloufi, Ebtesam H.,Alharshan, Najah A.,Almarwani, Ashwaq D.,Al-yami, Abeer A.,Alotaibi, Abeer A.,Alhazmi, Nada A.,Al-Boq International Journal of Computer ScienceNetwork S 2021 International journal of computer science and netw Vol.21 No.7

This study aimed to examine the Factor Structure of the teacher satisfaction scale (TSS) with distance education during the Covid-19 pandemic, as well as affirming the (Factorial Invariance) according to gender variable. It also aimed at identifying the degree of satisfaction according to some demographic variables of the sample. The study population consisted of all teachers in public education and faculty members in higher education in the Kingdom of Saudi Arabia. The (TSS) was applied to a random sample representing the study population consisting of (2399) respondents. The results of the study showed that the scale consists of five main factors, with a reliability value of (0.94). The scale also showed a high degree of construct validity through fit indices of the confirmatory factor analysis. The results have shown a gradual consistency of the measure's invariance that reaches the third level (Scalar-invariance) of the Measurement Invariance across the gender variable. The results also showed that the average response of the study sample on the scale reached (3.74) with a degree of satisfaction, as there are no statistically significant differences between the averages of the study sample responses with respect to the gender variable. While there were statistically significant differences in the averages with respect to the variable of the educational level in favor of the middle school and statistically significant differences in the averages attributed to the years of experience variable in favor of those whose experience is less than (5) years.

The Effectiveness of the Use of Distance-Evaluation Tools and Methods among Students with Learning-Difficulties from the Teachers' Point of View

Almaleki, Deyab A.,Khayat, Wejdan W.,Yally, Taghreed F.,Al-hajjaji, Aysha A. International Journal of Computer ScienceNetwork S 2021 International journal of computer science and netw Vol.21 No.5

This study aimed to identify the effectiveness of the use of distance-evaluation tools and methods among students with learning difficulties from the teachers' point of view, to achieve this goal. A scale was built, and the psychometric characteristics were validated. It consisted, in its final form, of 17 items distributed on four axes, in addition to three open questions. It was applied to a random sample of (149) teachers of students with learning difficulties in Makkah Region. The results showed that teachers' keenness to encourage students with learning difficulties, so that they would not feel frustrated with the distance learning process. It was also evident that teachers did not use achievement portfolios in the evaluation process. In connection with the appropriate evaluation methods, the majority indicated the use of work sheets and visual evaluation methods that rely on audio and visual skills, such as presenting videos, pictures, audio and games, and applying short objective tests. Among the proposals to improve evaluation methods and tools: Individual evaluation, attention to individual treatment, obligating personal attendance of students to school, splitting the required tasks, and not increasing the skills required to be mastered. As for the obstacles that teachers face: Lack of time, difficulty in communicating with students with distance learning difficulties and problems related to the Internet such as interruption, weakness, or lack of availability.

Impact on gene expression in response to silver-decorated titania nanomatrix using an in vitro satellite cell culture model

Amna, Touseef,Hassan, M. Shamshi,Al-Deyab, Salem S.,Khil, Myung-Seob,Hwang, Inho Springer-Verlag 2016 Polymer bulletin Vol.73 No.7

<P>Herein we report the synthesis of novel silver-ornamented titanium dioxide crossbreed nanofibers via electrospinning with improved cellular response for possible muscle tissue engineering applications. Titanium isopropoxide and silver nitrate served as precursors to get high aspect ratio silver-decorated titania nanofibers. For a model application in muscle tissue engineering, muscle satellite cells of local Korean Hanwoo were cultured on synthesized hybrid nanofibers. The standard microarray technique has been employed to screen the potential effects of synthesized nanofibers on genome after the culture of cells on hybrid nanofibers. EDX, EPMA, FT-IR, XRD and TEM analysis confirmed purity, distribution, interaction and crystalline nature of this material while the diameter of these nanofibers estimated from FE-SEM and TEM were between 200 and 300 nm. Cell counting with Kit-8 assay at regular time intervals and phase contrast microscopy data revealed that satellite cells proliferated well on nanofibers and cellular attachments were visible by SEM. Microarray analyses of gene expression response indicated clear changes in gene expression in a range of proliferation and apoptosis. Our results open-up new ways to develop and analyze gene expression biomarkers for satellite cell proliferation and finally muscle tissue engineering.</P>

Monodispersed 3D MnWO4-TiO2 composite nanoflowers photocatalysts for environmental remediation

M. Shamshi Hassan,Touseef Amna,Salem S. Al-Deyab,김현철,길명섭 한국물리학회 2015 Current Applied Physics Vol.15 No.6

Pollutants from textile industries into water-bodies have caused huge environmental hazards. The semiconductor mediated photocatalytic purification of polluted water is a promising environmental remediation technology. In the present study MnWO4-TiO2 composite nanoflowers endowed with efficient photocatalytic activity have been successfully synthesized by facile hydrothermal approach. XRD, SEM, TEM, EDX spectroscopy and UV-DRS were used to characterize the as-synthesized samples. The average size of composite nanoflower is ~2 μmwhile the nanorods constructing the nanoflowers had the average diameters of 90 nm. The photocatalytic activity of the MnWO4-TiO2 nanoflowers for the degradation of methyl orange (MO) in visible light was much higher than of pristine TiO2 nanorods and MnWO4 nanoflowers respectively. The superior photocatalytic activity could be attributed to the formation of a MnWO4-TiO2 heterojunction in the MnWO4-TiO2 nanoflowers.

Influence of Capsaicin on Inflammatory Cytokines Induced by Lipopolysaccharide in Myoblast Cells Under <i>In vitro</i> Environment

Shang, Ke,Amna, Touseef,Amina, Musarat,Al-Musayeib, Nawal M.,Al-Deyab, Salem S.,Hwang, Inho Medknow PublicationsMedia Pvt Ltd 2017 Pharmacognosy magazine Vol.13 No.49

<P><B>Background:</B></P><P>ellular damage initiated by reactive oxygen species (ROS) is the main cause of numerous severe diseases and therefore for this reason, the natural antioxidants have note worthy significance in human health. Capsaicin possesses noteworthy analgesic and anti-inflammatory properties. It also possesses healing effects for treatment of arthritis, diabetic neuropathy, gastric lesions, and cardiac excitability that is why it is incorporated in creams and gels.</P><P><B>Objective:</B></P><P>The present study was carried out to estimate the <I>in vitro</I> antioxidant and ROS scavenging activities of capsaicin against muscle precursor cells. Till date, no investigation has been carried out to study the effect of capsaicin on myoblasts.</P><P><B>Materials and methods:</B></P><P>Herein, the cytotoxicity was induced by endotoxin lipopolysaccharide (LPS) to analyze the effect of capsaicin on LPS induced inflammation and apoptosis on muscle cells. To find out the toxicity of endotoxin, myoblasts were exposed to different concentrations of LPS, viability and morphology was checkedby the means of CCK-8 test and microscopy, respectively. Apoptotic cell death was examined by fluorescence staining. Additionally, LPS-induced apoptosis was determined by mRNAexpression of calpain, caspase-3 and tumor necrosisfactor alpha (TNF-α), and were quantified by qRT-PCR.</P><P><B>Results:</B></P><P>The outcome of the presentstudy demonstrated that LPS stimulation generatestoxicity in dose-dependent manner. Pre-treatmentof myoblasts with capsaicin can considerably alleviate LPS-induced inflammation.</P><P><B>Conclusion:</B></P><P>In conclusion, this study indicates that dietetic supplementation of capsicum may help to alleviate/reduce the inflammatory effects and is therefore potent source of natural antioxidant agent which can be utilized to control muscle related diseases, such as myotube atrophy.</P><P><B>SUMMARY</B></P><P><P>In the present study cytotoxicity was induced by LPS to analyze the effect of capsaicin on LPS induced inflammation and apoptosis on muscle cells.</P><P>The results of this investigation demonstrated that LPS stimulation generates toxicity in dose dependent manner. Pre-treatment of myoblasts with capsaicin can considerably reduce LPS induced inflammation.</P><P>It has been concluded on the basis of results that the dietetic supplementation of capsicum may help to minimize inflammatory effects and are potent sources of natural antioxidants which can be utilized to control muscle related diseases such as atrophy.</P></P> >[FIG OMISSION]</BR><P><B>Abbreviation used:</B> AMP: Adenosine monophosphate, AO/EB: Acridine orange / Ethidium bromide, ATL: T-cell leukemi, CAP: Capsaicin, CCK-8: Cell counting Kit-8, CLSM: Laser Scanning Microscopy, DCF-DA: 2’, 7’-dichlorofluorescein diacetate, DMEM: Dulbecco’s modified Eagle’s medium, DPPH: α, α-diphenyl-β-picrylhydrazyl, FBS: Fetal bovine serum, KA: Kainic acid, LPS: Lipopolysaccharide, MDA: Malondialdehyde, NF-κB: Nuclear factor kgene binding, PBS: Phosphate buffer saline, pNA: p-nitroanilide, RNW: RNase free water, ROS: Reactive oxygen species, TNF-α: Tumor necrosis factor alpha, TRPV1: Transient receptor potential vanilloid 1</P>

Cobalt/copper-decorated carbon nanofibers as novel non-precious electrocatalyst for methanol electrooxidation

Barakat, Nasser A M,El-Newehy, Mohamed,Al-Deyab, Salem S,Kim, Hak Yong Springer 2014 NANOSCALE RESEARCH LETTERS Vol.9 No.1

<P>In this study, Co/Cu-decorated carbon nanofibers are introduced as novel electrocatalyst for methanol oxidation. The introduced nanofibers have been prepared based on graphitization of poly(vinyl alcohol) which has high carbon content compared to many polymer precursors for carbon nanofiber synthesis. Typically, calcination in argon atmosphere of electrospun nanofibers composed of cobalt acetate tetrahydrate, copper acetate monohydrate, and poly(vinyl alcohol) leads to form carbon nanofibers decorated by CoCu nanoparticles. The graphitization of the poly(vinyl alcohol) has been enhanced due to presence of cobalt which acts as effective catalyst. The physicochemical characterization affirmed that the metallic nanoparticles are sheathed by thin crystalline graphite layer. Investigation of the electrocatalytic activity of the introduced nanofibers toward methanol oxidation indicates good performance, as the corresponding onset potential was small compared to many reported materials; 310 mV (vs. Ag/AgCl electrode) and a current density of 12 mA/cm<SUP>2</SUP> was obtained. Moreover, due to the graphite shield, good stability was observed. Overall, the introduced study opens new avenue for cheap and stable transition metals-based nanostructures as non-precious catalysts for fuel cell applications.</P>

Electrochemical synthesis of a novel poly(2,5-dimethoxy aniline) nanorod for ultrasensitive glucose biosensor application

D. Ragupathy,이수출,Salem S Al-Deyab,A. Rajendren 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.3

We report for the first time a rapid electrochemical synthesis of one-dimensional poly(2,5-dimethoxyaniline) nanorods (PDMA-NR) in the presence of surfactant. FE-SEM and TEM imagesconfirm the PDMA-NR formation and the average diameter of single rod sizes in the range of ~200–300 nm. An enzymatic glucose biosensor was fabricated through immobilizing glucose oxidase (GOx)into PDMA-NR matrix. The amperometric current response of PDMA-NR/GOx to glucose is linear in theconcentration range between 1 and 10 mM with a detection limit of 0.5 mM (S/N = 3). The PDMA-NR/GOxelectrode possesses high sensitivity (5.03 mA/mM), selectivity, stability, and reproducibility towardglucose.

Preparation of nylon-6/chitosan composites by nanospider technology and their use as candidate for antibacterial agents

Mohamed Hassan El-Newehy,Salem Slayyem Al-Deyab,Rajkumar Nirmala,Ahmed Abdel-Megeed,Hak Yong Kim 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.2

Electrospun nylon-6/chitosan (nylon-6/Ch) nanofibers were prepared by nanospider technology. Quaternary ammonium salts as antibacterial agent were immobilized onto electrospun nylon-6/Ch nanofibers via surface modification by soaking the mat in aqueous solution of glycidyltrimethylammonium chloride (GTMAC) at room temperature overnight to give nylon-6/N-[(2-hydroxy-3-trimethylammonium)propyl] chitosan chloride (nylon-6/HTCC). The morphological,structural and thermal properties of the nylon-6/ch nanofibers were studied by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Fourier transform-infrared (FT-IR) spectroscopy, and thermogravimetric analysis (TGA). Biological screening has demonstrated the antibacterial activity of the electrospun nanofibers against Gram negative bacteria, Escherichia coli 35218, and Pseudomonas aeruginosa and Gram positive bacteria,Staphylococcus aureus 24213 among the tested microbes. Thus, the study ascertains the value of the use of electrospun nanofibers, which could be of considerable interest to the development of new antibacterial materials for biomedical applications.

One-step synthesis of electrically conductive polyaniline nanostructures by oxidative polymerization method

Dhanusuraman Ragupathy,Palanisamy Gomathi,이수출,Salem S. Al-Deyab,이상학,김한도 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.4

A simple, rapid and efficient route to prepare polyaniline nanostructures (PANI-NS) by ‘‘one-step chemical oxidative polymerization’’ method is described. This method possesses advantages in terms of good yield, short reaction time, neat conditions and cost-effectiveness. The morphology of the PANI-NS was investigated by field-emission scanning electron microscopy (FE-SEM). The average diameter of single PANI-NS was calculated to be 376 nm. Results from UV–visible spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and cyclic voltammetry (CV) reveals the existence of PANI units present in the polymeric nanostructures. Also, electrical conducting property of the PANI-NS was analyzed using four-probe measurement method.