The use of beta-carotene as environmentally safe inhibitor for Cu-Al-Ni alloyscorrosion in sulfide polluted chloride solutions

The stability of Cu-Al-Ni alloys used in the manufacture of NaCl in Egypt was investigated in sulfide polluted chloride solutions. Three different alloys, namely, Cu-10Al-5Ni, Cu-10Al-10Ni and Cu-10Al-45Niwereinvestigatedinchloride containingsulfide-ions using different electrochemical techniques including polarization and electrochemical impedance spectroscopy. The presence of sulfide ions in the chloride solution accelerates thecorrosion of Cu-Al-Ni alloys,whereas the increase of the nickel content in the alloy improves its corrosion resistance.?-carotene as eco-friendly corrosion inhibitor was used to protect the Cu-10Al-Ni alloys from corrosion in presence of sulfide ions. The corrosion inhibition efficiency reached >95% at 50 ppm of ?-carotene. The alloy surface was investigated by the scanning electron microscope and the surface constituents were analyzed by EDAX. Keywords: Corrosion; chloride, Cu-Ni alloys; EIS; sulfide pollution

Constructing an Instrument for Measuring the Selective Visual Attention of Basic-Stage Students in Gaza and Verifying its Psychometric Characteristics

The research aims at constructing an instrument for measuring the selective visual attention of basic education students in Gaza, and verifying its validity and reliability. The research sample consisted of 200   grade ten students in Khan Younis (for the academic year, 2018 -2019). The evidence of constructive validity and the factorial validity of the instrument were  investigated. Results of the predictive factorial analysis showed that the three tasks of the instrument  covered a single  potential factor  namely selective visual attention. All slides of the selective visual attention tasks have achieved statistically significant correlations with the overall scores of the instrument.  The content of the slides was also validated in relation to the instrument. The instrument reliability was also checked with the alpha coefficient for the final form of the instrument as a whole (0,962), and the split–half  reliability coefficients ranged from (0.770 – 0.907). The final form of the instrument  showed three major functions

Film forming gel for treatment of oral mucositis: In vitro studies

Oral mucositis is one of the main complications of non-surgical cancer treatments. The present work focuses on the treatment or reduction of oral mucositis by using combined mechanism by formation of physical barrier by forming a film to cover the oral ulcer and use of therapeutic agents, such as diclofenac sodium and ofloxacin separately or in combination. The selected polymers for film forming gel formulations are Hydroxypropylcellulose (HPC), hydroxypropyl methylcellulose (HPMC), sodium carboxymethylcellulose (Na CMC) and carbopol 940 (CP). The residence time in simulated buccal saliva was between 5.5 to 6 hours for all formulations. The in-vitro release data of the investigated drugs from the prepared formulations followed zero-order and diffusion mechanism. The permeability studies data revealed that diclofenac sodium showed higher permeability from Na CMC/CP (2:0.3%) than from HPMC 4%, while in case of ofloxacin higher permeability was shown from Na CMC/CP (2:0.3%) than from HPMC/HPC (2:3%). The permeation parameters for diclofenac sodium and ofloxacin in their combination do not depend on either viscosity or pH, they depend on the type of polymers used.Keywords: Mucositis; Film-forming gel; Rheology; In vitro studies

Impact Factors on Subcontractor's Cash Flow Management

Objective: This study aims to define how to maintain and protect the subcontractor firms' cash flow from economic fluctuation through legally sustainable solutions. Methods/Analysis: We conducted a case study in the Eastern Delta Region of Egypt. A questionnaire containing a list of 22 impact factors on subcontractors' cash flow was distributed across multiple subcontractor firms with an 82% response rate. It was designed to explore the factors causing cash flow instability and analyze them using SPSS statistics. Findings: The study finds that inflation, late payments, non-compensation for late payments, poor subcontractor cash flow management, subcontractor firms' inclination to avoid disputes, material price fluctuation, and non-compensation terms, as well as suppliers rejection of payment delays, are the most critical factors of subcontractor cash flow problems. Novelty/Improvement:The study suggests adding three sub-articles to Article 57 in "Tender Law" as legally sustainable solutions to protect and maintain the firm's growth rate from inflation, late payment, and the inclination to avoid disputes. Also, the study recommends that the owner ensure that cash is available before procuring the general contractors, as stated in Egyptian Law 182 of 2018. This study will contribute to establishing a sustainable win-win relationship between subcontractors and general contractors. Doi: 10.28991/CEJ-SP2023-09-08 Full Text: PD

Comparative study of biological characteristics of mesenchymal stem cells isolated from mouse bone marrow and peripheral blood

Mesenchymal stromal cells (MSCs) possess self‑renewal and multilineage differentiation potential, indicating their prospects as cellular therapeutic agents for regenerative medicine. Although adult bone marrow (BM) is the major source of these cells for clinical use, harvesting requires invasive procedures. Therefore, alternative sources, such as peripheral blood (PB), are needed. The objective of the current study was to compare PB‑MSCs and BM‑MSCs with regard to their biological characteristics. PB‑MSCs and BM‑MSCs were isolated from 4‑week‑old BALB/c white mice by density gradient centrifugation and cultured in DMEM + 10% fetal bovine serum until passage four. Morphological features, proliferation, cell surface marker expression and trilineage differentiation potential were assessed for both PB‑MSCs and BM‑MSCs. No significant differences in morphological features were observed. BM‑MSCs had a higher proliferative capability than PB‑MSCs as measured by XTT assays. Both PB‑MSCs and BM‑MSCs had broadly similar cell surface marker expression, but PB‑MSCs had positive expression of cluster of differentiation (CD)146 and CD140b. Both PB‑MSCs and BM‑MSCs were capable of trilineage differentiation. Although BM‑MSCs had a greater capacity for osteogenic and chondrogenic differentiation than PB‑MSCs, PB‑MSCs had a better capability for adipogenic differentiation than BM‑MSCs. In conclusion, PB‑MSCs and BM‑MSCs have very similar biological characteristics. Thus, PB is a promising source for easily obtaining MSCs in mice

Ultrastructural and Molecular Changes in the Developing Small Intestine of the Toad Bufo regularis

The ontogenetic development of the small intestine of the toad Bufo regularis was investigated using twofold approaches, namely, ultrastructural and molecular. The former has been done using transmission electron microscope and utilizing the developmental stages 42, 50, 55, 60, 63, and 66. The most prominent ultrastructural changes were recorded at stage 60 and were more evident at stage 63. These included the appearance of apoptotic bodies/nuclei within the larval epithelium, the presence of macrophages, swollen mitochondria, distorted rough endoplasmic reticulum, chromatin condensation, and irregular nuclear envelop, and the presence of large vacuoles and lysosomes. The molecular investigation involved examining DNA content and fragmentation. The results showed that the DNA content decreased significantly during the metamorphic stages 60 and 63 compared with both larval (50 and 55) and postmetamorphic (66) stages. The metamorphic stages (60 and 63) displayed extensive DNA laddering compared with stages 50, 55, and 66. The percentage of DNA damage was 0.00%, 12.91%, 57.26%, 45.48%, and 4.43% for the developmental stages 50, 55, 60, 63, and 66, respectively. In conclusion, the recorded remodeling of the small intestine represents a model for clarifying the mechanism whereby cell death and proliferation are controlled

Stability of Some Copper Ternary Alloys in Chloride Solutions Polluted by Sulfide Ions

The electrochemical performance of three copper alloys was investigated in simulated marine solution polluted by sulfide ions. Polarization techniques and electrochemical impedance spectroscopy, EIS, were used. Surface examination and morphological studies were employed. The results showed that the Cu-10Ni-10Zn alloy is more stable than the other two alloys. The alloy surface was covered by a barrier layer protecting it from corrosion. The thickness and resistance of the barrier layer formed on the Cu-10Ni-10Zn alloy increases with the increase of the immersion time. The mechanism of the corrosion process and the barrier film formation was discussed.  A comparison was made between the electrochemical stability of the three alloys in sulfide polluted chloride solution. The incorporation of Ni in the Cu2O barrier film leads to its stabilization and the stability is enhanced by the presence of Zn. The results leads to the recommendation of the Cu-10Ni-10Zn alloy for applications in sulfide polluted marine environments. Keywords:  Copper alloys, EIS, Polarization, SEM, Passive Films

Optimization of Reduction Process of Egyptian Ilmenitevia Metallothermic reactions

It is important to develop technologies for the production of master alloys for industrial applications. Detailed research on reduction of titanium from Egyptian ilmenite by an aluminothermic process in a graphite Crucible was charged by the mixture of ilmenite, flux, aluminum was investigated. This paper study the effect of aluminum feed (10%- 35%), flux material (type, and amount), and temperature preheat from 50 oC to 400 oC and time of preheating from 0.5 hr. to 3 hrs.  Then, the metallic samples formed by the reduction were analyzed using X-ray diffraction, scanning electron microscopy. The mixed fluxes were strongly and successfully reduced ilmenite to a high-purity master alloy with small amounts of detected impurities. Key words: Aluminothermic, Egyptian ilmenite, flux, ferrotitanium, master alloy DOI: 10.7176/CMR/11-7-04 Publication date:September 30th 2019

Quadcopter Aggressive Maneuvers along Singular Configurations: An Energy-Quaternion Based Approach

Automatic aggressive maneuvers with quadcopters are regarded as a highly challenging control problem. The aim is to tackle the singularities that exist in a vertical looping maneuver. Modeling singularities are resolved by writing the equations-of-motion of the quadcopter in quaternion form. Physical singularities due to underactuation are resolved by using an energy-based control. Energy-based control is utilized to overcome the uncontrollability of the quadcopter at physical singular configurations, for instance, when commanding the quadcopter to gain altitude while pitched at 90∘. Three looping strategies (circular, clothoidal, and newly developed constant thrust) are implemented on a nonlinear model of the quadcopter. The three looping strategies are discussed along with their advantages and limitations

Biological and molecular characterization of fEg-Eco19, a lytic bacteriophage active against an antibiotic-resistant clinical Escherichia coli isolate

Characterization of bacteriophages facilitates better understanding of their biology, host specificity, genomic diversity, and adaptation to their bacterial hosts. This, in turn, is important for the exploitation of phages for therapeutic purposes, as the use of uncharacterized phages may lead to treatment failure. The present study describes the isolation and characterization of a bacteriophage effective against the important clinical pathogen Escherichia coli, which shows increasing accumulation of antibiotic resistance. Phage fEg-Eco19, which is specific for a clinical E. coli strain, was isolated from an Egyptian sewage sample. Phage fEg-Eco19 formed clear, sharp-edged, round plaques. Electron microscopy showed that the isolated phage is tailed and therefore belongs to the order Caudovirales, and morphologically, it resembles siphoviruses. The diameter of the icosahedral head of fEg-Eco19 is 68 +/- 2 nm, and the non-contractile tail length and diameter are 118 +/- 0.2 and 13 +/- 0.6 nm, respectively. The host range of the phage was found to be narrow, as it infected only two out of 137 clinical E. coli strains tested. The phage genome is 45,805 bp in length with a GC content of 50.3% and contains 76 predicted genes. Comparison of predicted and experimental restriction digestion patterns allowed rough mapping of the physical ends of the phage genome, which was confirmed using the PhageTerm tool. Annotation of the predicted genes revealed gene products belonging to several functional groups, including regulatory proteins, DNA packaging and phage structural proteins, host lysis proteins, and proteins involved in DNA/RNA metabolism and replication.Peer reviewe