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In this paper, the impact of small additions of indium (In), nickel (Ni), and Titanium dioxide nanoparticles (TiO2 NPs) in the microstructure and characterization of eutectic Sn–0.7 Cu (SC07)-based solder were investigated. The third element In, Ni, or TiO2 NPs were added in varying amounts 0.4 or 0.8 wt% to SC07 alloy by replacing an equal amount of Sn for each addition. Structural analysis of the investigated samples showed that the addition of Ni or In modified the eutectic composition, leading to the appearance of primary phases (Cu6Sn5) followed by the formation of intermetallic compounds (IMCs) (Cu, Ni)6Sn5 and Cu6(Sn, In)5. However, addition of TiO2 NPs did not lead to formation of any new IMCs but refine β-Sn dendrites grains with a decrease in the volume fraction of Cu6Sn5 IMC. The crystallite size, lattice strain, and dislocation density of the SC07 solder alloy were improved in terms of third addition. The results indicated that the smallest crystallite size for SC07–0.8In associated with largest lattice strain and highest dislocation density. Microhardness tests were performed for all samples at room temperature. The results illustrate the enhancement indentation creep resistance of SC07 reinforced solder, which inherently correlates to the microstructure refinement and the formation of intermetallic phases (Cu, Ni)6Sn5 and Cu6(Sn, In)5 with higher hardness values. The obtained stress exponent values are in the range 9.26–11.46 for all tested alloys which close to that creep mechanisms associated with dislocation movement such as dislocation creep are predominant. Thus, we conclude that the greatest value of stress exponent for SC07–0.8In (10.9–11.46) at different loads suggested to be more resistant to indentation creep which improves the mechanical strength compared to other solders. [ABSTRACT FROM AUTHOR]

This study introduces a new series of complexes and adducts, denoted by [M(2-PhOEtXant)2.nL], where M represents Mn(II), Fe(II), Co(II), or Ni(II), and the ligand (2-PhOEtXant) is 2-Phenoxyethylxanthate. Varying ligands, including pyridine, piperidine, quinoline, ethylenediamine, and (1,10)-phenanthroline, are explored based on the value of n. Comprehensive characterization, encompassing techniques like ¹H-NMR, 13C-NMR, FTIR, AA, CHN analysis, UV-visible spectroscopy, and magnetic property measurements, is employed. Results indicate an octahedral geometry for these complexes, as revealed by effective magnetic moment measurements and electronic spectra analysis. The compounds exhibit noteworthy antioxidant properties, demonstrated through the DPPH radical scavenging method, highlighting their potential as effective antioxidants. Moreover, the complexes display enhanced antibacterial activity against microbial strains compared to free ligands. This research not only delves into the coordination chemistry of these complexes but also underscores their diverse applications. Combining experimental methods with computational insights using Density Functional Theory (DFT) enhances the understanding of dithiolate transition metal complexes. The alignment of computational and experimental outcomes strengthens the reliability of the findings, laying a robust foundation for interdisciplinary exploration. The identified potential applications in optoelectronics, along with the notable antioxidant and antibacterial activities, position these complexes as promising contenders for advanced technologies and scientific applications. [ABSTRACT FROM AUTHOR]

The time-dependent electrophoresis of an infinitely cylindrical particle in an electrolyte solution, saturated in a charged porous medium after the sudden application of a transverse or tangential step electric field, is investigated semi-theoretically with an arbitrary double-layer thickness in an arbitrary direction relative to the cylinder. The time-dependent modified Brinkman equation with an electric force term, which governs the fluid flow field, is used to model the porous medium and is solved by using the Laplace transform technique. Explicit formulas, for the time-dependent electrophoretic velocity of the cylindrical particle in Laplace's transform domain, have been derived for both axially and transversely when the uniform electric fields are imposed. They can also be linearly superimposed for an arbitrarily oriented relative to the electric field. Semi-analytical results for the electrophoretic velocities are presented as functions of the dimensionless elapsed time, the ratio of the particle radius to the Debye length, the particle-to-medium density ratio, and the permeability parameter of the porous medium. The results demonstrate, in general, that the growth of the electrophoretic velocities with the time scale are more slower for high permeability, and the effect of the relaxation time for unsteady electrophoresis is found to be negligible, regardless of the thickness of the double layer, the relative mass density or the permeability of the medium. The normalized transient electrophoretic velocities exhibit a consistent upward trend as the ratio of the particle radius to the Debye screening length increases. Conversely, they display a consistent downward trend as the particle-to-fluid density ratio increases, while all other parameters remain constant. The effect of the relaxation time for the transient electrophoresis is much more important for a cylindrical particle than for a spherical particle due to its smaller specific surface area. [ABSTRACT FROM AUTHOR]

This work involved the synthesis of compositions of Ba0.95Ca0.05SnxTi1-xO3 (BCST) with varying amounts of Sn dopant (x = 0, 0.02, 0.04, 0.06, 0.08, and 0.1). A standard solid-state reaction approach was used to create all of the ceramic compounds. Each BCST composite's microstructure, sintering, morphology, density, optical, and electrical characteristics were carefully examined, and the dielectric performance was optimized. In comparison to the unmodified composite, introducing varied amounts of Sn material into the BCST compound changed the crystal lattice vibrations and functional group locations. This result indicates that there are some variations in unit cell size, revealing that Sn+4 ions diffused effectively inside the lattice structure to produce BSCT composites. Further, SEM micrographs indicated proportionate changes in the homogenous structure and irregular forms as Sn concentration increased, as well as some variation in average grain size. As a consequence, by adding 0.08 mol% of Sn dopant, the crystallite size and average grain size were adjusted to 45.69 nm and 0.66 µm, respectively. Meanwhile, the 0.08-Sn specimen displayed a dielectric constant (Ɛ) with an optimum value of 5557 and a relative decrease in the Curie-Weiss constant. These results are attributed to the existence of various concentrations of Sn ions at the Ti-site of the BCT, which resulted in a compositionally disordered state. This disordered condition is essential for the production of dielectric compounds. Therefore, it is evident that modifying the amount of Sn doping added significantly enhanced the dielectric characteristics of the BCST composites created in this work. However, excessive Sn doping reduces the dielectric properties due to a reduction in tetragonal phase and an increase of disorders and charge fluctuations. Highlights: Synthesis and characterization of Ba0.95Ca0.05SnxTi1-xO3 (BCST) compositions with varying amounts of Sn dopant. A standard solid-state reaction approach was used to create all of the ceramic compounds. The dielectric characteristics of the BCST proved to be highly dependent on the amount of Sn doping employed. [ABSTRACT FROM AUTHOR]

The research focuses on the synthesis and characterization of a novel xanthate ligand and their complexes with the formula [M(PhOEtXant)2], where M represents as Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II), and PhOEtXant stands for 2-Phenoxyethylxanthate. The antioxidant activities of these complexes will be evaluated by comparing them with standard natural antioxidants and ascorbic acid using the (DPPH) assay. The synthesized complexes were thoroughly characterized based on their physical properties using various spectral methods, like XRD, FTIR, NMR, AA, UV-Visible, magnetic properties, and conductivity measurements. The complexes are nonelectrolytes, according to molar conductance measurements. Infrared spectra revealed that the ligand acts as a neutral bidentate moiety in all the compounds. Electronic spectra and effective magnetic moments suggested that the compounds exhibit a tetrahedral shape, which is supported by the experimental data. For further insights into the geometry, bond length, bond angle, electronic characteristics, and thermodynamic factors of the synthesized compounds, a density functional theory (DFT) approach with the basis set GGA-PBE was employed for optimization. The antioxidant evaluation using the DPPH assay demonstrated that all the complexes displayed significant radical scavenging activity when compared to the standard ascorbic acid. Remarkably, the Cu, Zn, Ni, and Mn complexes showed superior radical scavenging activities compared to the other complexes and the standard ascorbic acid. Overall, this research highlights the promising potential of the synthesized complexes as effective antioxidants, showcasing their value for further exploration in various applications related to antioxidant research and potentially in therapeutic contexts. The comprehensive characterization using a range of spectroscopic and computational techniques provides valuable insights into their structure and properties, supporting their potential applications in diverse fields of chemistry. [ABSTRACT FROM AUTHOR]

Pathogenic bacteria causing diseases in broiler chicks are widely distributed. One hundred and fifty cases of broiler chick samples were obtained from 15 farms with complain of early mortalities. Out of them, 100 diseased and 50 freshly dead chicks aged 1 - 14 days were examined. Liver, heart blood, lung, yolk sac and thigh bones were collected. Bacteriological investigation in both diseased and freshly dead chicks revealed that the prevalence rate of E. coli was 70% with higher incidence in liver followed by yolk sac, S. aureus isolates represented as 18.5% mainly from thigh bone followed by liver, incidence of Pseudomonas aeruginosa was 20% mainly from yolk sac proceeded by liver, Klebsiella pneumonia incidences was 13.3% with high rate from liver. Prevalence of all previous isolated bacteria was higher in freshly dead than in diseased chicks. Serological identification of 68 isolates of E. coli (64.8%) were typed with 5 different serotypes as 15 (O119:H6), 8 (O1:H7), 10 (O146:H21), 20 (O78), 8 (O29) and 7 (O144) while 37 (35.2%) were untyped. E. coli antimicrobial resistance was performed with marked sensitivity reported with amoxicillin. PCR performed for detection of some virulence genes mainly eaeA and iss from E. coli isolates, and enterotoxin B (SEB) and enterotoxin D (SED) from S. aureus isolates with positivity 100% for each genes. This study indicated presence of some pathogenic bacteria in broiler chicks up to two weeks as E. coli, S. aureus, Pseudomonas aeruginosa and Klebsiella pneumoniae which cause diseases with a consequence of economic losses. [ABSTRACT FROM AUTHOR]

A CT scan of a pregnant patient is often a source of distress for the patient and staff. In addition, patients are usually worried about the risk of unfavorable effects on the fetus from radiation. Therefore, assessing radiation dose and related risks to the fetus and pregnant patient is an important aspect of radiation protection. The aim of this study is to estimate the fetal organ and effective dose during a chest CT protocol for a pregnant patient. For this purpose, we model the SOMATOM EMOTION 16 CT (Siemens Medical Solutions, Erlangen, Germany) and the pregnant patient using GATE code. The CT scanner is modelled based on the data provided by the supplier, operating at 80, 110 and 130 kV and 0.5–1.5 for the pitch, regarding the patient, she is modelled with a voxelized pregnant phantom (KATJA, 29 yr old) at the 24th week. Fetal effective doses are estimated to be 0.8, 1.7 and 2.4 mSv for 80, 110 and 130 kV, respectively. When the energy is decreased from 130 to 80 kV, the dose to the fetal organs in the heart and lenses is reduced by 64.3 and 64.6%. Moreover, the fetus organ dose is reduced by 21.5, 19.2, 30.0 and 17.6% for crane, eyes, heart and brain for a pitch ranging from 0.5 to 1.5. Since the cumulative dose to the fetus does not exceed 100 mGy, the doses to the fetus are considered acceptable. [ABSTRACT FROM AUTHOR]

The use of environmentally friendly pesticides using palm oil derivatives as palm oil methyl ester (PME) carrier solvents has been reported. PME-based glyphosate isopropylamine nanoemulsion in the water against weeds has been the subject of numerous studies as well as palm oil methyl ester molluscicidal against golden apple snails. This study's major goal was to formulate palm oil in an appropriate formulation form and assess its insecticidal effectiveness against citrus mealybug, Planococcus citri. Palm oil was formulated as 34% oil in water emulsion (O/W) (mayonnaise). The new mayonnaise formulation successfully passed all physical and chemical testing requirements set out by pesticide organizations for (O/W) emulsions. Under laboratory conditions, it was biologically evaluated against nymphs and adults of the citrus mealybug, Planococcus citri, with serial concentrations. It had considerable insecticidal activity against all study stages, although the impact on nymphs was significantly greater than that on adults. This was evident from its LC50 values, which were 53.52 and 58.58 mg/ml for nymphs and adults, respectively. The citrus mealybug, Planococcus citri, in its adult, nymphs, and gravid stages, was tested using the new palm oil 34% mayonnaise formulation in the field. The highest mortality percentages were seen in the nymphs, followed by adults and then the gravid stage. After additional research, the newly developed palm oil formula might be employed to combat the citrus mealybug, Planococcus citri. [ABSTRACT FROM AUTHOR]

A semi-analytical study is presented for the thermophoretic migration of a spherical particle located at an arbitrary position in a porous medium inside a spherical cavity. A uniformly applied temperature gradient parallel to the line connecting the particle and cavity centers. The porous medium is modeled as a Brinkman fluid with a characteristic Darcy permeability K that can be obtained directly from the experimental data. The porous medium is assumed to be homogenous and isotropic, and the solid matrix is in thermal equilibrium with the fluid through the voids of the medium. The Knudsen number is supposed to be small so that the fluid flow through the porous medium can be described by a continuum model with a temperature jump, a thermal creep, a frictional slip, and thermal stress slip at the surface of the aerosol particle. The Reynolds number of the fluid is assumed to be small enough to justify the use of the Brinkman equation, which is always satisfied because the aerosol particle is so small. The Péclet number for heat transfer in thermophoresis is also assumed to be small. The dimensionless thermophoretic velocity and the mobility coefficients are tabulated and represented graphically for various values of the permeability parameter and relative thermal and surface properties of the particle and cavity. Results are in good agreement with the analytical solution of the particular case of a particle located at the center of the cavity. [ABSTRACT FROM AUTHOR]

Optimization and statistical methods are used to minimize the number of experiments required to complete a study, especially in corrosion testing. Here, a statistical Box–Behnken design (BBD) was implemented to investigate the effects of four independent variables (inhibitor concentration [I], immersion time t, temperature ϑ, and NaCl content [NaCl]) based on the variation of three levels (lower, middle, and upper) on the corrosion protection efficiency of the green inhibitor oleoylsarcosine for low-carbon steel type CR4 in salt water. The effects of the selected variables were optimized using the response surface methodology (RSM) supported by the Minitab17 program. Depending on the BBD analytical tools, the largest effects were found for ϑ, followed by [I]. The effect of interactions between these variables was in the following order: [I] and ϑ > t and ϑ > [I] and [NaCl]. The second-order model used here for optimization showed that the upper level (+1) with 75 mmol/L for [I], 30 min for t, and 0.2 mol/L [NaCl] provided an optimal protective effect for each of these factors, while the lower level (−1) was 25 °C for ϑ. The theoretical efficiency predicted by the RSM model was 99.4%, while the efficiency during the experimental test procedure with the best-evaluated variables was 97.2%. [ABSTRACT FROM AUTHOR]

Understanding the M23C6 carbides precipitation sequence aims to determine a correct heat treatment design in order to optimise the mechanical properties of the Fe-18Cr-8Ni steel. In this paper, the ageing influence at 800°C on the mechanical properties and microstructure of this steel has been studied. The aged material was examined with nanoindentation, macrohardness, scanning electron microscopy, light microscopy, and X-ray diffraction techniques. The hardness test results showed a continuous softening of the Fe-18Cr-8Ni steel when increasing the treatment time up to 6000 minutes. The nanoindentation tests revealed a decrease in the nanohardness of the austenite and M23C6 carbides as the ageing time increased. Before the ageing process, the solution treatment produced completely austenitic steel. After 30 and 60 minutes of ageing, the M23C6 carbides were located at the grain boundaries. The precipitation of the M23C6 carbides within the grains was observed from 300 to 6000 minutes of ageing. The coarsening of the M23C6 carbides occurred at high holding times. [ABSTRACT FROM AUTHOR]

To investigate the corrosion protection behavior of naturally derived cocoyl sarcosine in combination with N-b-hydroxyethyl oleyl imidazole for steel CR4 in 0.1 M NaCl, different evaluation systems (weight loss, electrochemical measurements, and spray corrosion tests) were used. Both compounds were tested in different concentrations (25–100 mmol/L) and with variable dip coating times (1–30 min), first individually and then in combination, to check any synergistic effects for surface protection. Both showed only an insignificant corrosion inhibiting effect with less than 50% efficiency at all concentrations and dip coating times if used alone. In contrast, compound combinations revealed an improved corrosion inhibition correlated with higher concentrations. Across all methods, the compound combination concentration of 100 mmol/L resulted in improved efficiency of up to 83% for gravimetric tests, up to 84% for the impedance measure and more than 91% for potentiodynamic polarization. Dip coating variations proved 10 min to be the best option for all compounds with a maximum efficiency of up to 86% for the compound combination. [ABSTRACT FROM AUTHOR]

The present research work aims to study the heat treatment effect on the structural and mechanical properties of the tool steel AISI D2. The steel has undergone a double treatment. First, the iron-based alloy was subjected to a normalizing, the explored temperatures are 975, 1025 and 1075°C for a holding time of 1 hour. Then, the steel is annealed at temperatures ranging from 250 to 650°C for 2 hours. The structural and mechanical properties of the tool steel AISI D2 was studied by several experimental methods: hardness measurement, optical microscopy, scanning electron microscopy and X-ray diffraction. After the heat treatments, the mechanical properties of the steel decreased compared to as-received state. According to the microscopic study, the softening is due to the precipitation of cementite present as spherical and isolated particles in a matrix of ferrite. [ABSTRACT FROM AUTHOR]

The toxicity of benzothiazole derivatives obtained from 2-cyanomethyl benzothiazole against cotton leafworm Spodoptera littoralis 2nd and 4th instar larvae has been documented. The main objective of this research was to formulate two previously reported chromen derivatives and test their biological activity against cotton leafworm S. littoralis 2nd and 4th instar larvae under laboratory conditions. According to the standard method, two chromen derivatives with two distinct substituents (salicylaldehyde and 2-hydroxy-1-naphthaldehyde) were synthesized. Their physical and chemical properties were evaluated, and both were formulated as 10 and 9.5 percent dustable powder formulations. Both formulae were then evaluated in the laboratory on cotton leafworm S. littoralis 2nd and 4th instar larvae for mortality and developmental effect percentage. Formulation (F2) was more efficient than formulation (F3) in both cases and for both stages. Furthermore, when comparing the developmental effects on the 2nd and 4th instar larvae, the 4th instar larvae demonstrated marked tolerance. Both stages were unable to complete their life cycle. Histopathological analysis of samples from the affected stages was performed to assess the mode of action of these formulations on 4th instar larvae at their LC50 values. Experimental data showed that Formulation (F3) resulted in epidermal cells separated from the cuticular layer, necrosis, ruptured columnar cells with pyknotic nuclei, disrupted basement membrane, and weak epicuticle necrosis and separation. In comparison, formulation (F2) revealed a midgut with vacuoles, damaged columnar, muscle cell necrosis, and a ruined peritrophic matrix. Thus, the cotton leafworm S. littoralis could be combated with the newly prepared formulations (F2) and (F3). [ABSTRACT FROM AUTHOR]

The feasibility of using nano-cryptomelane for elimination of cobalt and cesium metal ions from their single and binary solutions was studied. In this respect, the material was prepared and characterized to confirm its chemical composition and structure. Results illustrate that the synthesized nano-cryptomelane has a tunnel structure with particle size ranged between 4 and 6 nm. The material feasibility was detected by conducting a series of batch experiments for determination of the kinetic and equilibrium performance of the removal process. All characteristic Raman bands for Mn–O lattice vibrations within the (2 × 2) tunnel structure of MnO6 octahedral are observed which confirm formation of nano-cryptomelane. The specific surface area (SSA) for nano-cryptomelane was calculated and equal to 299.03 m2/g while the surface fractal information (Ds) was2.53. The process sensitivity to changes of H+ concentration is attributed to changes in structural elements-species distribution at the solid/aqueous interface. The pH optimum value was desired at pH 5 for exchange of Cs+ and/or Co2+ with K+ ions. The equilibrium studies show that Langmuir isotherm model was more fitted to the experimental data than that of Freundlich model. [ABSTRACT FROM AUTHOR]

Clove oil is reported to have a great range of biological activities against many species of pests; termites, cockroaches, aphids, weevils and moths, and many different usages such as perfume and food flavoring agent. This study aimed to determine the acaricidal activity of clove oil emulsifiable concentrate new formulation against two-spotted spider mites Tetranychus urticae. Clove oil was formulated as 10 % emulsifiable concentrate (EC). The new formula passed successfully all physical and chemical tests reported for emulsifiable concentrates. It was then tested biologically on the individuals of two-spotted spider mite T. urticae Koch (Acari: Tetranychidae) on two host plants beans and squash under laboratory conditions. In both cases, there were a direct relationship between the increase in the concentration of the formulation and the percentage of inhibition on the individuals of the two-spotted spider mite, after 72 hours of treatment, at concentrations of 20, 40, and 80 mg/ml the new formulation showed 10.30, 44.8, and 75 percent inhibition, respectively in case of beans, while squash at the same concentrations and for the same period of treatment showed 33.3, 40.7, and 51.9 percent inhibition, but the effect in case of beans was greater than that in case of squash as its EC50 value was lower than that in case of squash. In the case of the former, it was 39.81 mg/ml, whereas in the case of the latter, it was 79.43 mg/ml. Therefore, the new clove oil formulation can be used to combat the two-spotted spider mite. [ABSTRACT FROM AUTHOR]

In this study, the objective was to give more data related to the use of GATE (Geant4-based Application for Tomographic Emission) and Al2O3:C Optically Stimulated Luminescence (OSL) nanodots, as two alternative methods to estimate entrance surface dose (ESD) in mammography. First, ESD values were simulated with GATE and compared with values measured with Al2O3:C OSL nanodots and Solid State kV/dose Multisensor AGMS-M+ (Radcal,USA), using a standard breast phantom MTM100 (CIRS, USA). On the other hand, GATE simulations were also performed with PMMA slabs of different thicknesses (10 to 90 mm) and then compared with experimental values using AGMS-M+ detector. Results pointed to a maximum difference of 17%, between X-ray spectra simulated with GATE and those calculated with the IPEM report number 78 software, for this reason, the air kerma factor was calculated with GATE and IPEM and compared to the one measured by the AGMS-M+ detector. The ESD results indicate that GATE and Al2O3:C OSL nanodots values were compatible within 4% with those obtained with AGMS-M+. This work gives more data according to the use of GATE and Al2O3:C OSL nanodots to determine the ESD. Indeed, in the literature, there are few studies related to the use of GATE code and Al2O3:C OSL nanodots in mammography systems. [ABSTRACT FROM AUTHOR]

2,3,7,8,12,13,17,18-Octaethyl-21H,23H-porphine (OEP) was successfully radiolabeled with technetium-99m by direct technique using two different reducing agents: stannous chloride and sodium borohydride. High radiochemical yield (97%) and in vitro stability for up to 8 h were obtained using sodium borohydride. Paper chromatography (PC), paper electrophoresis, and high-performance liquid chromatography (HPLC) were used to evaluate the radiochemical yield and identify the purity of the final product. Biodistribution studies of the 99mTc-OEP complex (prepared using sodium borohydride) in tumor-bearing mice showed high target/nontarget (T, right thigh/NT, left thigh) ratio of 4.40 ± 0.12 at 60 min post injection, suggesting that this complex can be used as a solid tumor imaging agent. [ABSTRACT FROM AUTHOR]

Delonix regia pods have been used to produce high-efficiency and low-cost activated carbons using different activation methods. The ability of these prepared sorbents to remove cations [137Cs, 85Sr, La(III), Eu(III), Co(II), U(VI)] and anions [75Se, Cr(VI), Mo(VI)] was evaluated in mono-component systems and the sorbents number 11, 13, 25, and 35 showed high removal efficiency. These sorbents also show the high ability to remove organic pollutants such as methylene blue and phenol. This study highlighted the extensive applicability of these low-cost sorbents in the sequestration of anionic and cationic radionuclides from real radioactive wastewaters and different environmental samples. [ABSTRACT FROM AUTHOR]

This work relates to the study and characterization of the CTDI (Computed Tomography Dose Index) for the 16 slices CT scanner. The CTDI has been simulated with the Monte Carlo code GATE for PMMA (polymethylmethacrylate) digital phantoms of various diameters (1–50 cm) at various kVp (80, 110, 130) and mAs (100, 200, 300, 400 mAs) levels. After using a High-Performance Computing (HPC) station, a good agreement was observed (less than 1.18% for head phantom and 1.85% for body phantom for all applied voltages) between simulations and experimental measurements with standard PMMA phantoms. Results of simulations demonstrated the following. Firstly, GATE is an adapted tool to estimate CTDI values and can be used to optimize CT parameters in clinical applications. Secondly, Monte Carlo simulation may be able to estimate the absorbed dose when the CTDI method has limitations (use of homogeneous standards cylindrical phantom, the dose measurement in air not in tissue). [ABSTRACT FROM AUTHOR]

Pathogen-based factors associated with tuberculosis (TB) in eastern Sudan are not well defined. We investigated genetic diversity, drug resistance, and possible transmission clusters of Mycobacterium tuberculosis complex (MTBC) strains by using a genomic epidemiology approach. We collected 383 sputum specimens at 3 hospitals in 2014 and 2016 from patients with symptoms suggestive of TB; of these, 171 grew MTBC strains. Whole-genome sequencing could be performed on 166 MTBC strains; phylogenetic classification revealed that most (73.4%; n = 122) belonged to lineage 3 (L3). Genome-based cluster analysis showed that 76 strains (45.9%) were grouped into 29 molecular clusters, comprising 2-8 strains/patients. Of the strains investigated, 9.0% (15/166) were multidrug resistant (MDR); 10 MDR MTBC strains were linked to 1 large MDR transmission network. Our findings indicate that L3 strains are the main causative agent of TB in eastern Sudan; MDR TB is caused mainly by transmission of MDR L3 strains. [ABSTRACT FROM AUTHOR]

Gum acacia/polyacrylamide (GA/PAAm) hydrogel was prepared using gamma radiation. The effect of preparation conditions such as radiation dose, copolymer composition, and initial feed concentration were investigated. The hydrogel of equal copolymer ratio was chosen for trapped SiO2 nanoparticles to prepare (GA/PAAm/SiO2) nanocomposite. In situ preparation of the magnetic nanocomposite and the magnetization was measured. Characterization of the prepared hydrogel and the nanocomposites was performed using (FT-IR), (FESEM), (HRTEM), (XRD), and (EDX). The elastic modulus and the hardness are sequence in order of; GA/PAAm/SiO2- MNC > GA/PAAm/SiO2> GA/PAAm. [ABSTRACT FROM AUTHOR]

The temperature influence on the structural and mechanical properties of AISI 420 stainless steel is studied. The iron-based alloy underwent normalizing at three temperatures 975, 1025, and 1075°C for 1 h, followed by annealing at temperatures ranging from 250 to 650°C for 2 h. At both treatment stages, steel is air-cooled. The material was examined with nanoindentation, macrohardness, scanning electron microscopy, light microscopy, and X-ray diffraction. For each normalizing temperature, the two stages of the mechanical behavior were observed. At the first stage, in which macrohardness and nanohardness decrease slightly over temperature range of 250–450°C, and the second one is characterized by a significant loss of these mechanical properties corresponding to 550 and 650°C temperatures. At the microstructural level, softening of AISI 420 steel occurs due to dissociation of large cementite into smaller spheroids. [ABSTRACT FROM AUTHOR]

Potential natural and environment-friendly substances are often used as substitutes for inhibitors to protect steel against corrosion in a sustainable way. Here, three biodegradable N-acyl sarcosine derivatives are evaluated for corrosion protection by polarisation, weight loss, electrochemical impedance, optical and scanning electron microscopy (SEM) spectroscopy including energy dispersive spectroscopy (EDS) to find the best possible application interval of concentration and dip-coating time. The substances present vary in their carbon chain length on the sarcosine-amino acid and are tested in 0.1 M NaCl as protective barrier for low-carbon steel CR4. Corrosion protection improved with increasing sarcosine concentration in the dip-coating stock solutions (25, 50, 75, and 100 mmol/L). Best efficiencies were found in polarisation for the highest studied concentrations of Oleoylsarcosine (O) with 97% followed by Myristoylsarcosine (M) with 82%. The lowest overall performance showed the shorter Lauroylsarcosine (L) with 51%. The best immersion time for dip-coating on CR4 for present compounds turned out to be 10 min. Surface analysis results with SEM and EDS revealed a significant higher C content caused by increased film-forming adsorption of sarcosines on the metal surface. [ABSTRACT FROM AUTHOR]

The quasi steady axisymmetrical flow of an incompressible viscous fluid past an assemblage of porous sphere situated at an arbitrary position within a virtual spherical cell along the line connecting their centers is analyzed using a combined analytical-numerical technique. At the fluid-porous interface, the stress jump boundary condition for the tangential stresses along with continuity of normal stress and velocity components are employed. The Brinkman model governs the flow inside the porous particle and the flow in the fictitious envelope medium is governed by Stokes equations. A general solution is constructed from the superposition of the fundamental solutions in the two spherical coordinate systems based on both the porous particle and virtual spherical cell. Boundary conditions on the particle's surface and the fictitious spherical envelope for four known cell models are satisfied by a collocation method for truncated series. Numerical solutions for the drag force exerted on the porous sphere in the presence of the cell are obtained for various cases of the effective distance between the center of the porous particle and the fictitious envelope, the volume ratio of the porous particle over the surrounding sphere, the viscosity ratio, the stress jump coefficient, and a coefficient that is proportional to the permeability. Streamlines in and around porous sphere are presented for the unit cell models at different values of relevant physical parameters. In the limits of the motions of the porous particle in the concentric position with the cell surface and near the cell surface with a small curvature, the numerical values of the normalized drag force are in good agreement with the available values in the literature. [ABSTRACT FROM AUTHOR]

An experiment was designed to study the effect of different heat combating practices during acute heat stress on productive and physiological performances of Cobb500 chicks. Total of 540 one-day old of Cobb500 chicks was randomly divided into six equal groups with three replicates (30 birds in each). The first group was subjected to neutral temperature (NT), the second group was under chronic heat stress as a control (CHS), the third group was exposed to early heat acclimation (EHA), the fourth group was exposed to feed restriction (FR), the fifth group was supplemented with 1 g vitamin C/Kg diet (Vit.C), and the six group was treated with a combination of the last three treatments (EFC). It was observed that, CHS group recorded the highest value in respiratory, mortality rate, serum liver enzymes activities (ALT and AST), serum glucose concentrations and the lowest body weight, feed intake, feed conversion ratio, serum concentrations of triiodothyronine (T3) and thyroxine (T4) hormones, serum immunoglobulin concentration, serum lipid profile levels, livability among groups, while, exposed chicks to different heat combating practices: NT, EFC, Vit.C, FR and EHA, respectively, decreased significantly chicks mortality, serum corticosterone concentration hormone and improved the livability percentages, body weight, feed intake, feed conversion ratio, serum immunoglobulin concentrations and had better results for serum ALT and AST activities. Furthermore, EFC and NT groups recorded the highest significant EPEI values (18.38 and 17.48) respectively, and serum concentrations of triiodothyronine (T3) and thyroxine (T4) hormones compared to the other groups. It can be concluded that EFC treatment showed the best practical method compared to the other groups to enhance the production performance and immunity status followed by T5, T4 and T3. Therefore, these methods can be applied in broilers farms to increase the economic return [ABSTRACT FROM AUTHOR]

Graphene (GR) sheets were successfully prepared via solvent interface trapping. Characterization of GR was performed using Raman spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), high-resolution transmission electron microscopy (HRTEM), and UV-Vis spectrometer. GR was trapped in gum acacia (GA) and polyacrylamide (PAAm) to form GA/PAAm/GR nanocomposite using gamma irradiation technique. In situ preparation of the magnetic nanocomposite and the magnetization was measured. Characterization the prepared nanocomposites was done using (FT-IR), (FESEM), (HRTEM), (XRD), (TGA). It can be obtained that a high swelling percent was observed for all systems that increased with time until reached the steady state after 5 h and the maximum was at pH 10. The swelling percent were ordered in sequence of GA/PAAm-magnetic > GA/PAAm/GR-magnetic > GA/PAAm > GA/PAAm/GR. The thermal stability of the magnetic nanocomposite was higher than non-magnetic one. The mechanical properties were determined using nanoindentation. The elastic modulus and the hardness of GA/PAAm matrix increased by adding GR and GR-magnetic in the nanocomposites. [ABSTRACT FROM AUTHOR]

This study shows the effects of heat treatment on the manganese steel which microstructure consists essentially of 18.447% of manganese, 0.745% of chromium, and 1.169% of carbon. The techniques used are: X-ray diffraction, optical microscope, scanning electron microscope.After heat treatment at 600 °C and 1050 °C for 30 minutes, metallurgical analysis will connect the microstructural changes occurring during the temperature maintenance to the mechanical behavior of the material. The characterization of the microstructures and the surface morphology of the alloy before and after the heat treatment determine that this treatment process favors the dispersion of carbides in the austenitic matrix and the appearance of precipitates which causes structural hardening. [ABSTRACT FROM AUTHOR]

Silicon carbide was mixed with alumina and kaolin to obtain porous alumino-silicate bonded SiC ceramics. Starch was added as sacrificial template. The mixtures were processed by hand-pressing and extrusion method. The effect of firing temperature (1450 ∘C) and the addition of starch on the composition and characteristics of fired specimens were studied. The changes in phase composition and microstructure of fired SiC specimens were followed through x-ray diffraction analysis and scanning electron microscopy, respectively. The sintering parameters and thermal oxidation in air of such specimens were determined. The results indicated that silicon carbide is oxidized during firing into silica which reacted with silica-alumina mixture forming alumino-silicate bonding. Meanwhile, starch burnt out leaving pores inside the specimens. Porous SiC specimens of 1.72 to 1.79 g.cm−2 bulk density, 40 to 45% open porosity and 250 to 350 N.cm−2 compressive strength could be obtained by using a mixture of 80 mass% SiC and 20 mass% alumina and kaolin as starting materials. The properties of porous SiC specimens depend on the type and amount of used starch. The extrusion method is favorable for preparing porous SiC articles of homogeneous microstructure and good properties. [ABSTRACT FROM AUTHOR]

Ageing of supersaturated solid solution in Pb - 3.2% Cd - 0.08% Sr alloy is studied at 20 and 80°C by measuring hardness, and light and scanning electron microscopy. Structural changes are established corresponding to stages of ageing and supersaturation. [ABSTRACT FROM AUTHOR]

In this study we compared the effect of three different concentrations of MoO3 on the corrosion of sodium phosphate glass containing lead and aluminum oxides to develop its durability. The corrosion was studied in deionized water and acidic solution of 0.1 N HCl. The dissolution mechanism is interpreted depending on the glass weight loss versus time and change in the glass surface. MoO3 had a stabilizing effect on the glass, causing a decrease in the glass dissolution rate. Acidic medium was found to strongly enhance the glass dissolution. The pH decrease in water with increase in acidic solution gives evidence of the release of some phosphorous ions to form phosphoric acid. The consequent enhancement of the glass durability was influenced by the presence of MoO3 and showed a remarkable advance by doping with 3 wt% of MoO3. FT-infrared absorption spectra of the studied glasses show IR vibrational bands due to phosphate groups mainly of the metaphosphate and pyrophosphate units together with the sharing and interference of IR vibrations due to Pb-O bonds. Gamma irradiation produces a minor effect on the IR spectra, and enhances the base glass durability at the beginning of the corrosion process, which can be related to the shielding behavior of the high lead glass. However, glass containing 3% MoO3 has the best durability and is the least affected by irradiation. The glass durability corresponding to its structure is verified by IR spectroscopy. [ABSTRACT FROM AUTHOR]

Background. In Sudan, tuberculosis diagnosis largely relies on clinical symptoms and smear microscopy as in many other low- and middle-income countries. The aim of this study was to investigate the positive predictive value of a positive sputum smear in patients investigated for pulmonary tuberculosis in Eastern Sudan. Methods. Two sputum samples from patients presenting with symptoms suggestive of tuberculosis were investigated using direct Ziehl-Neelsen (ZN) staining and light microscopy between June to October 2014 and January to July 2016. If one of the samples was smear positive, both samples were pooled, stored at −20°C, and sent to the National Reference Laboratory (NRL), Germany. Following decontamination, samples underwent repeat microscopy and culture. Culture negative/contaminated samples were investigated using polymerase chain reaction (PCR). Results. A total of 383 samples were investigated. Repeat microscopy categorized 123 (32.1%) as negative, among which 31 were culture positive. This increased to 80 when PCR and culture results were considered together. A total of 196 samples were culture positive, of which 171 (87.3%), 14 (7.1%), and 11 (5.6%) were M. tuberculosis, M. intracellulare, and mixed species. Overall, 15.6% (57/365) of the samples had no evidence of M. tuberculosis, resulting in a positive predictive value of 84.4%. Conclusions. There was a discordance between the results of smear microscopy performed at local laboratories in the Sudan and at the NRL, Germany; besides, a considerable number of samples had no evidence of M. tuberculosis. Improved quality control for smear microscopy and more specific diagnostics are crucial to avoid possible overtreatment. [ABSTRACT FROM AUTHOR]

Three selected borosilicate glasses of commercial applications were prepared and studied for their corrosion behavior by the accepted grain test method towards acidic and alkaline solutions and distilled water before and after gamma irradiation. The work was supplemented by investigating the FT infrared absorption spectra of the glasses after immersion through the KBr disc technique. The same IR measurements have been repeated after gamma irradiation. Experimental weight loss data reveal limited changes which vary with the type of leaching solution and its strength. Alkali hydroxide solutions cause more weight loss than acidic solutions due to their reactions with all glass constituents including silicate and borate species beside modifier ions while distilled water and acidic solutions react or attack the modifier ions through ion exchange corrosion behavior. FTIR spectral results show characteristic vibrational peaks due to combined silicate and borate groups which reveal an interconnected compact network structure within the mid region of wavenumber range 800-1400 cm−1. This is due to the presence of four structural building units consisting mainly of SiO4 beside BO3, BO4 and AlO4 groups. The vibrational spectra slightly change with the immersion media because of the strong and compact network structure usually identified in borosilicate glasses. The commercial glass of the Schott type is the most durable studied glass because of high silica content (75%) together with combined 10% B2O3 and 5% Al2O3. Gamma irradiation results indicate minor changes in the weight loss data due to the compact network structure of the three commercial borosilicate glasses studied. [ABSTRACT FROM AUTHOR]

Symbolic regression is commonly performed using evolutionary algorithms like genetic programming (GP). The goal of this research work is to construct symbolic models from examples where a new symbolic regression approach based on artificial neural networks is proposed. This approach is composed of a long-term artificial neural network memory (LTANN-MEM), a working memory (WM) in addition to a proposed neural symbolization algorithm (NSA) which uses LTANN-MEM and WM for synthesizing symbolic models equivalent to learning examples. The proposed LTANN-MEM is composed of two separate multilayer perceptron (MLP) feed-forward neural networks as well as the working memory which is composed of a single MLP. The core idea of the proposed approach is based on memorizing the learning experience of individual perceptrons in long-term memory (LTM), so they become available to be reused in generating and developing hypotheses about the learning examples. Although this idea is generic and could be used for the purpose of symbolization in general, it is applied here in symbolic regression for Boolean domain only. The obtained results show the ability of the proposed approach to search the solutions space using learning experience stored previously in LTM to guide the search process. A comparison is done with GP and found that the proposed NSA algorithm outperforms GP in its performance when increasing the number of inputs and outputs in the same problem by comparing the number of emerged candidate solutions in both approaches. [ABSTRACT FROM AUTHOR]

In order to master and improve the quality and properties of the final products, the major industrial challenge lies in the possibility of controlling the morphology, size of microstructures that reside within the molded pieces, as well as their defects; this is the fundamental reason according to which we are more and more interested in mastering the growth and germination of such alloys, as well as the developing structures, at the time of solidification process. On the one hand, the whole work focuses upon the modeling of the homogenization effect according to the three parameters: time, temperature and composition, and seeing each one influence upon the silicon concentration according to the distance between the surface and the core of the ingot, on the other hand, the purpose of this work is to model the influence of silicon addition upon the cooling process and various mechanical properties of aluminum. Usually, the microstructure and mechanical behavior of such alloys as Al-Si are directly influenced by some parameters such as composition, cooling velocity and homogenization process. [ABSTRACT FROM AUTHOR]

The verified Darcy-Brinkman model and boundary perturbation method are used to study the Brinkman flow in a tube with a bumpy surface, assuming the amplitude of the bumps is small compared to the mean tube radius. This study is important to understand the abnormal flow conditions caused by the boundary irregularities in diseased vessels. The mean rate flow is found, up to second-order correction, as a function of circumferential and longitudinal wave numbers and the permeability parameter of the porous medium. Numerical results displaying the velocity components and bumpiness functions are obtained for various values of the physical parameters of the problem. The results are tabulated and represented graphically for various physical parameters. It is found that, for every permeability parameter and for given bump area, there exists a circumferential wave number, for which the flow resistance is minimized. The limiting cases of Stokes and Darcy's flows of the bumpiness function are discussed and compared with the available results in the literature. [ABSTRACT FROM AUTHOR]

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This study is aimed at investigating the drying kinetic of Myrtus communis L. leaves by fluidisation at controlled temperatures and air speeds and fitting it to eight mathematical models existing in the literature. Five experiences were carried out for three airflows (Va=1, 0.8 and 0.3 m/s) and three temperatures (40, 50, 60 °C). Fitting of experimental drying curves to the models pointed out that « Modified Henderson and Pabis» model is the most suitable for describing the drying kinetic of this product. [ABSTRACT FROM AUTHOR]

Extraction of Pd(II) from nitric acid solution with CYANEX 471X in chloroform was carried out using liquid–liquid extraction and emulsion liquid membrane (ELM) techniques. Extraction equilibrium was postulated using the slope analysis method. KSCN solution efficiently stripped Pd(II). In the ELM investigations, the effects of the different parameters affecting the membrane stability were studied. The prepared membrane was found to be selective for Pd(II) extraction in the presence of some interfering ions and its permeation reached 98%. The kinetics of Pd(II) permeation through the prepared membrane indicated that the rate of permeation depends on the carrier, Pd(II), and nitric acid concentration. [ABSTRACT FROM AUTHOR]

This paper presents a boundary perturbation method of the Brinkman-extended Darcy model to investigate the flow in corrugated microannuli cylindrical tubes with slip surfaces. The stationary random model is used to mimic the surface roughness of the cylindrical walls. The tube is filled with a porous medium. We shall consider the two cases where corrugations are either perpendicular or parallel to the flow, and particular attention is given to the effect of the phase shift. The effects of the corrugations on the flow rate and pressure gradient are investigated as functions of wavelength, the permeability of the medium, the radius ratio and the slip parameter. Particular surface roughnesses are examined as special cases of stationary random surface. It is found that the effect of the partial slip is significant on the corrugation functions. The limiting cases of Stokes and Darcy's flows and no-slip case are discussed. [ABSTRACT FROM AUTHOR]

Hastelloy C2000 is a superalloy used in the chemical processing, pollution control and waste treatment industries. This alloy contains a nominal amount of 52-60% of Ni, 15-31% of Cr, 9-16% of Mo, and small additions of other elements such as iron, copper, tungsten, etc. Its matrix is austenitic and its structure is face-centered cubic. The objective of our work is to study the structure of the Hastelloy C2000 and this by a heat treatment at four temperatures: 700 °C, 800 °C, 900 °C and 1000 °C with a prolonged maintenance at each temperature during three hours. The monitoring of the structure is performed by using the X-ray diffraction (XRD). The X-ray diffraction spectra obtained after the heat treatments, show the presence of peaks of the precipitates and the peaks of the austenite phase. For the crystallographic parameters of the mesh before and after the four heats treatments, we remark an increase of the parameter a and the volume of the mesh as a function of treatment temperature. [ABSTRACT FROM AUTHOR]

This work is aimed at investigating the microstructure and mechanical properties of as-cast Al-Cd alloys system were prepared by casting technique. The Al-Cd binary aluminium alloy was analyzed by employing Rockwell hardness HRF, metallograph, XRD, SEM and EDS methods. Evolution of hardness confirmed that the studied alloys are age-hardenable alloys. The as-cast Al-2%Cd alloy is the one who present the mechanical properties (48,75HRF) improved compared to other studied alloy. The results of XRD and optical microscope revealed the presence of the one main phase a-Al of a crystalline structure CFC and there is no new phase formed. [ABSTRACT FROM AUTHOR]

Hastelloy C2000 is a nickel-base superalloy. With the addition of copper to nickel-chromium-molybdenum system, it is resistant to a wide range of corrosive chemicals as well as the combination of molybdenum and copper creates an excellent corrosion resistance to reducing media, while the high content of the chrome provides a good oxidation resistance. Its structure is face-centered cubic. The value of our work is to study the stability of the Hastelloy C2000 on its microstructure and mechanical properties and this by a heat treatment at four temperatures: 700→, 800→, 900→ and 1000→ with a prolonged maintenance at each temperature for three hours. The monitoring of these two aspects is performed using the following experimentals techniques: optical microscopy and hardness measurement. After heat treatment, the pictures obtained by optical microscopy revealed the presence of different morphologies of carbides, joints and inside the grains, also we remark the appearance of the discontinuous transformations and the coalescence phenomenon of grain to form a larger area of precipitation. For hardness in the over-aging, it attains a final value of 47 for the four samples treated at 700→, 800→, 900→ and 1000→. [ABSTRACT FROM AUTHOR]

Nowadays, the issue of scheduling multi-core real-time systems has become the focus of such research in industrial, biomedical, military, and other fields. As a consequence, a new semi-partitioning algorithm that uses a static Rate-Monotonic criterion to schedule real-time tasks on multi-core platforms is proposed. The improvement in the performance of real-time systems is achieved by exploitingthe fact that the utilization boundary of a task set increases to fully utilize the processors if the periods of tasks have harmonic nature among each other. Experimental results on randomly generated datasets and real-world datasets show that the proposed algorithm inevitably outperforms other competitive algorithms. [ABSTRACT FROM AUTHOR]