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Sediments are utilized as a marker for events that endure long enough to manifest their environmental impacts and determine the contamination levels. The purpose of the present study was to highlight the current sediment quality of four Nile islands shores by utilizing a variety of physical, chemical, and biological aspects and indices. In addition, the status of benthic diatoms and macroinvertebrates, as well as their responses to sediment variables were investigated. The metals followed a decreasing concentration order: Al > Fe > Mn > Zn > Ni ≈ Cr > Cu > Co > Pb > Cd. The outcomes of metal pollution indices revealed some localized contaminated sites, by mostly Ni and Cd. In addition, a moderate toxic risk from metals was observed for El-Keratten shores, while the sediments of El-Warraq, El-Zamalek, and El-Manial islands shores were at low toxic risk. A total of 112 diatom species belonging to 24 genera were identified in the total sample set, where most of the diatoms encountered were cosmopolitan. Metals had a remarkable impact on the composition, distribution, and dominance of diatom assemblages, but had little effect on diatom diversity, while there was a noticeable effect of grain size on diatom distribution and diversity. Thirty-four species of benthic invertebrates were identified in the collected samples from the islands shores. The dominant taxa and groups of benthic invertebrates at different islands were affected by various sediment parameters, where the levels and types of such variables differed from one species to another. Graphical abstract

Deterioration or crack formation in concrete elements is a phenomenon that cannot be easily avoided, and it has a high cost of repair. A modern technology that needs wider study is the use of the bio-precipitation of calcium carbonate using bacteria to increase a structures’ capacity. The current research presents an analytical study on self-healing concrete beams using bacteria to enhance the beam’s capacity. A Finite Element Analysis on (ANSYS 15.0) was carried out to study the effect of the bacteria concentration (the weight of bacteria to cement weight 1%, 2%, and 3%), the type of bacteria (Bacillus subtilis, E. coli, and Pseudomonas sps.), and the loading (a one-point load, a two-point load, and a distributed load on four points) on concrete beams. Two beams were chosen from previous experimental research and simulated on the ANSYS before carrying out our parametric study to verify the validity of our simulation. Following this, our parametric study was carried out on eight beams; each beam was loaded gradually up to failure. The results show that the optimum type of bacteria was the Bacillus subtilis, and that the bacteria concentration of 3% for Bacillus subtilis can increase the beam’s capacity by 20.2%. Also, we found that distributing the load to four points led to the increase of the beam’s capacity by 74.5% more than the beam with a one-point load.

The alarming rise of multi-drug resistant (MDR) Pseudomonas aeruginosa has prompted the World Health Organization to consider it a serious threat to human health. Although phage (Phg), an effective...

Math anxiety (MA) describes feelings of tension, apprehension and fear that interfere with math performance. High MA (HMA) is correlated with negative consequences, including lower math grades, and ultimately an avoidance of quantitative careers. Given these adverse consequences, it is essential to explore effective intervention strategies to reduce MA. In the present functional magnetic resonance imaging (fMRI) study, we investigated the efficacy of cognitive reappraisal as a strategy to alleviate the effects of MA. Cognitive reappraisal, an emotion regulation strategy, has been shown to decrease negative affect and amygdala responsivity to stimuli that elicit negative emotion. We compared a reappraisal strategy to participants’ natural strategy for solving math problems and analogies. We found that HMA individuals showed an increase in accuracy and a decrease in negative affect during the reappraisal condition as compared to the control condition. During math reappraise trials, increased activity in a network of regions associated with arithmetic correlated with improved performance for HMA individuals. These results suggest that increased engagement of arithmetic regions underlies the performance increases we identify in HMA students when they use reappraisal to augment their math performance. Overall, cognitive reappraisal is a promising strategy for enhancing math performance and reducing anxiety in math anxious individuals.

AA2124 reinforced with graphene (G), silicon carbide nanoparticles (SiCnp), and graphene-coated SiCnp (GCSiCnp) were fabricated and characterized. GCSiCnp reinforcement was fabricated by ball milling, followed by mixing and milling the reinforcements with AA2124 powders. Consolidation was achieved by cold compaction and hot extrusion (HE). The powders’ morphology and structural evolution were characterized with XRD and SEM. Microhardness and tensile properties were also characterized. Increasing the fillers’ content beyond 5 wt pct deteriorated the composites’ mechanical properties due to the agglomeration of the fillers. Adding 5 wt pct GCSiCnp increased the hardness, specific strength, and modulus of the composite and decreased ductility. Furthermore, 5 wt pct SiCnp induced severe lattice strain by intra-granular dispersion strengthening. The GCSiCnp filler strengthened the Al-matrix via the strong interfacial bonding of the intercalated inter-granular lamination of the hybrid particles within the Al-matrix and the intra-granular dispersion strengthening associated with the individual SiCnp. Adding 5 wt pct G lowered the HE composite’s density and hardness significantly, while the sliding of G-intercalated layers coating the Al-grains facilitated plastic flow along the extrusion direction and enhanced the strength and ductility of the composite compared to that containing 5 wt pct GCSiCnp.

Novel non-sulfonylureas derivatives bearing an acetamide linker between a spirohydantoin scaffold and a phenyl ring were prepared and their hypoglycemic activity was estimated in vivo . Their abilities to discriminate in vitro between aldehyde reductase (ALR1) and aldose reductase (ALR2) were determined. The molecular docking and the in silico prediction studies were performed to rationalize the obtained biological results and to predict the physicochemical properties and drug-likeness scores of the new compounds. N -(2,4-Dichlorophenyl)-2-(2′,4′-dioxospiro[fluorene-9,5′-imidazolidine]-3′-yl)acetamide ( 3e ) displayed an 84% reduction in blood glucose level superior to that of repaglinide 66% and showed an IC 50 value of 0.37 μM against ALR2 that is superior to that of sorbinil 3.14 µM. Compound ( 3e ) was selective 96 fold towards ALR2 which is closely related to serious diabetic complications. Based on the identification of this hit candidate, a new generation of safe and effective antidiabetic agents could be designed.

The Nile River is the soul of Egypt, providing more than 95% of its freshwater demand. However, it receives different pollutants discharged into the water body along its stretch from Aswan (downstream of the High Dam) to Cairo, which is approximately 950 km. Alternatively, sediments play an important role in the dynamics of the entire aquatic environment and act as a sink or a source of pollution in the overlying water under various conditions. This study assessed sediment quality and its heavy metal levels. Several indices and human health risks were determined to assess the potential ecological risk of the Nile River sediment. On the basis of the index results, Cd registered the highest pollution ranking, whereas Fe, Mn, Zn, Cu, and Ni had the lowest effect. In another context, southern sites represented the lowest ecological risk relative to the central and northern sectors. The results of the noncarcinogenic hazard indices, hazard quotient, and hazard index in addition to the lifetime cancer risk were below the acceptable international limits, confirming that there are no adverse effects on the exposed population due to the Nile sediment.

Recently, several severe plastic deformation (SPD) techniques have been developed with the aim of incorporating grain refinement and strengthening metal forming technology into the industry without dimensional changes. Multi-channel spiral twist extrusion (MCSTE) was innovated and patented in an attempt to provide an effective, cost-saving SPD process that would attract the industrial uptake of the renowned twist extrusion (TE) method. The MCSTE process is based on the use of customized stacked disks that host non-circular cross-sectioned billets extruded through a die with a twist angle (β). Hence, an empirical study was conducted on AA1100 to investigate the influence of 4 successive MCSTE passes on the mechanical behavior and microstructural evolution of the extrudates compared to the as-received (AR) condition. Electron backscatter diffraction (EBSD) was employed for mapping the structural evolution, misorientation angles and the texture developed as a function of the processing passes. Additionally, hardness and tensile properties were evaluated and correlated with the EBSD findings. EBSD analysis revealed the formation of almost equiaxed grains after 1 pass, which were evolved into elongated grains aligned at approximately 45° relative to the extrusion direction after 2-passes. Moreover, MCSTE processing 1-pass produced a structure with 64% and 36% HAGB and LAGB, respectively, while 2-passes via MCSTE increased HAGBs to 80%. Processing 4-passes increased the amount of recovery depicted by the percentage of LABs within the grains, which was associated with a noticeable increase in the fraction of fine grains

Novel derivatives of spiroimidazolidinedione were synthesized and evaluated as hypoglycemic agents through binding to sulfonylurea receptor 1 (SUR1) in pancreatic beta-cells. Their selectivity index was calculated against both aldehyde reductase (ALR1) and aldose reductase (ALR2). Aldehyde reductase is a key enzyme in the polyol pathway that is involved in the etiology of the secondary diabetic complications. All structures were confirmed by microanalysis and by IR, 1H NMR, 13C NMR and EI-MS spectroscopy. The investigated compounds were subjected to molecular docking and an in silico prediction study to determine their free energy of binding (ΔG) values and predict their physicochemical properties and drug-likeness scores. Compound 1′-(5-chlorothiophene-2-ylsulfonyl)spiro[cyclohexane-1,5′-imidazolidine]-2′,4′-dione showed IC50 0.47 µM and 79% reduction in blood glucose level with a selectivity index 127 for ALR2.

Multi-channel Spiral Twist Extrusion (MCSTE) is introduced as a novel severe plastic deformation (SPD) technique for producing superior mechanical properties associated with ultrafine grained structure in bulk metals and alloys. The MCSTE design is based on inserting a uniform square cross-sectioned billet within stacked disks that guarantee shear strain accumulation. In an attempt to validate the technique and evaluate its plastic deformation characteristics, a series of experiments were conducted. The influence of the number of MCSTE passes on the mechanical properties and microstructural evolution of AA1100 alloy were investigated. Four passes of MCSTE, at a relatively low twisting angle of 30 deg, resulted in increasing the strength and hardness coupled with retention of ductility. Metallographic observations indicated a significant grain size reduction of 72 pct after 4 passes of MCSTE compared with the as-received (AR) condition. Moreover, the structural uniformity increased with the number of passes, which was reflected in the hardness distribution from the peripheries to the center of the extrudates. The current study showed that the MCSTE technique could be an effective, adaptable SPD die design with a promising potential for industrial applications compared to its counterparts.

This paper presents a recursive digital low-dropout (RLDO) regulator that improves response time, quiescent power, and load regulation dynamic range over prior digital LDO designs by 1–2 orders of magnitude. The proposed RLDO enables a practical digital replacement to analog LDOs by using an SAR-like binary search algorithm in a coarse loop and a sub-LSB pulse width modulation duty control scheme in a fine loop. A proportional-derivative compensation scheme is employed to ensure stable operation independent of load current, the size of the output decoupling capacitor, and clock frequency. Implemented in 0.0023 mm2 in 65 nm CMOS, the 7-bit RLDO achieves, at a 0.5-V input, a response time of 15.1 ns with a figure of merit of 199.4 ps, along with stable operation across a 20 000 $\times $ dynamic load range.

Background: liver transplantation surgically replaces a failing or diseased liver with one that is normal and healthy. At this time, transplantation is the only cure for liver insufficiency or liver failure because no device or machine reliably performs all of the functions of the liver. Aim of the Work: this study aimed to highlight risk factors of the venous thromboembolism in donors of living donor liver transplant and its management. Patients and Methods: this study included 40 patients who underwent hepatectomy for living donor liver transplant. All patients were evaluated extensively, including history and physical examination and specialty consultations when indicated. All patients did haematological studies to detect the risk factors of thromboembolic disease. Results: in patients with manifestations of venous thromboembolism 2 donors have single risk factor for venous thromboembolism and 4 donors have double risk factors. Conclusion: presence of multiple risk factors for venous thromboembolism led to increase in its incidence, so during preoperative assessment of the donors, if they have multiple risk factors for thrombosis some precautions should be taken to avoid venous thrombosis. Recommendations: preoperative precautions include heamatological consultations for the donors and prophylaxis dose of anticoagulant. Intra operative precautions included pneumatic calf pressure, elastic stocking. Finally postoperative precautions should be continued , these donors should take therapeutic doses of anticoagulants and follow up by lower limb venous duplex.

A fully integrated CMOS power amplifier (PA) that efficiently generates high-voltage RF waveforms directly from a 4.8-V supply using only low-voltage thin-oxide transistors is introduced. High-voltage operation is achieved via implicit ~100% efficient dc–dc conversion enabled by stacking and flying individual class-D PA cells in a House-of-Cards (HoC) topology. By dynamically reconfiguring digitally controlled HoC slices to support different voltage conversion ratios and capacitively coupling their outputs, a Doherty-like high-efficiency backoff profile is achieved without using any magnetic impedance inverter. A test chip, implemented in 65-nm low-power CMOS, operates directly from 4.8 V using only 1.2-V transistors, and attains above 40% battery-to-RF efficiency at both 23-dBm peak power and at 6-dB backoff at 720 MHz. When applying a 10-MHz 16-quadrature amplitude modulation signal, the PA achieves an error vector magnitude of 3.6%-rms without using any predistortion techniques with an average output power and power-added efficiency of 15.7 dBm and 26.5%.

In the current research, the mechanical and tribological behavior, and structural evolution of AA2124-3 and 5-wt.% graphene (G) composites prepared by a combination of ball milling and hot extrusion were investigated. Properties such as macro and micro-hardness, nanohardness, tensile and lattice strain were characterized. Wear rates, coefficient of friction (COF) as well as nanoscratch testing were used to investigate the self-lubricating tribological behavior. X-ray diffraction, optical and scanning electron microscopy were employed. Hardness of the AA2124-G composite increased by 133 and 102%, the wear rates decreased by 34 and 25%, and the COF decreased by 25 and 9%, for the 3 and 5 wt.% G composites, respectively compared to the plain alloy extrudates. The AA2124-3 wt.% G composite displayed the least scratch depth and width and highest nanohardness. The uniform distribution of the 3-wt.% G-particles within the Al-matrices formed uniform G-tribofilm, which enhanced the tribological behavior of the composite.

This paper presents a new power conversion method that can achieve both high efficiency and high power density by obviating the need for an area-consuming flying capacitor and replacing it with a flying digital load. The proposed flying-domain (FD) power conversion concept enables higher conversion efficiency than a conventional switched-capacitor converter by reducing charge-sharing and bottom-plate parasitic losses, while also enabling higher power density by eliminating the area occupied by the flying passive itself. This paper presents state-space analysis that shows that the proposed FD concept is well posed and reaches a valid steady state, while also presenting experimental results of several FD converters implemented in 180 nm SOI. With no flying passives, the fabricated FD converter achieves a peak efficiency of 99.2%, delivers up to 11.8 W/mm2 (2.3 W/mm2 with decoupling) at 91.7% efficiency, and can directly power a cofabricated Cortex M0 processor that communicates via flying I/O level shifters.

Ti6Al4V lattice structures were fabricated using selective laser melting with a wide range of processing parameters, namely laser power and scan speed, in order to study their effect on strut diameter and internal porosity morphology. Hence, identifying the optimum processing condition. Scanning electron microscopy (SEM) and optical microscopy (OM) were used to investigate the influence of these parameters on the strut size and internal porosity within the struts. The results show that at low laser power conditions the strut size decreased with increasing the scan speed. At intermediate laser power (200 W) the strut size decreased until it reached 2400 mm/s, beyond which no pattern was observed. Fluctuations in strut size values were found at different scan speeds using high laser power (250 W, 300 W). The micrographs of the sectioned lattice structures showed various morphologies of the internal porosity, from which a process map was developed to pinpoint the various types of defects at the different processing conditions. Five zones were formed which are: gas porosity, keyholing, irregular defects, balling, and lack of fusion defects. SLM processing condition of 100 W–1600 mm/s was selected to be the best condition from the studied samples for producing the lattice structure with strut size closest to the design and with minimum internal porosity. Mechanical and microstructural analysis were performed for this condition.

Recent advancements in integrated radio design have enabled many new applications ranging from wearable health-care or fitness monitors to Internet of Things devices, structural integrity monitors, and beyond. In many of these applications, device size and battery life are of critical importance. Since radios often consume a significant portion of the power budget in small sensing nodes [1], reducing radio power consumption is an effective way to decrease battery size or increase battery life. Reducing radio power consumption can be challenging as there are important tradeoffs between power consumption and performance metrics such as radiated output power, linearity, sensitivity, channelization capabilities, and interference sensitivity. Low-power radio designs often sacrifice one or more of these metrics in the pursuit of low overall power consumption.

Sediment samples have been collected from Lake Nasser during drought and flooding periods to study the effect of flood season on bottom sediment distribution and mode of transportation. Ten sectors with three sites in each sector were chosen from upstream of Aswan High Dam to Adindan. The study showed that Lake Nasser sediments are heterogeneous and are mainly silty clay and clayey silt. Eastern and western sides of the lake include more sand. Depth controlled distribution of grain size (deeper is finer). Sands increase with the starting of the flood season. During drought periods suspension was the most predominant mode of transportation; i.e. sediments transported by a medium of considerable density. During flooding period siltation and suspension were most predominant modes of transportation; i.e. environment with a high energy, various overlapping processes, and variety of depositional environments. C–M diagram indicates that sediments during drought periods behaved as pelagic suspension in which sediments settled from a suspension in stagnant water, rolling; overbank facies suspension and uniform suspension were of less importance. During the flooding period there was no clear trend for studied sediments of pelagic suspension; rolling, graded suspension, overbank facies suspension, suspension, and uniform suspension were widely distributed.

Introduction The concern on the effect of pupillary dilatation on visual field parameters in patients with glaucoma comes from the fact that patients usually seek field examination after their pupils have been dilated for fundus examination. Aim To investigate the influence of pupillary dilatation on visual field testing in patients with glaucoma, by using automated static perimetry. Patients and methods A prospective comparative noninterventional clinical study was conducted on 20 eyes (11 patients) with open-angle glaucoma. Two consecutive visual field examinations were performed on each eye of all participants. The first was done on the undilated normal pupil size, whereas the second was done after dilating the pupil to 6–8 mm. Results After pupillary dilatation, fixation losses were significantly higher. There was no significant difference in false-negative or false-positive results. There was improvement in the mean deviation with no statistical significance. Pattern standard deviation showed also improvement, which was statistically significant. Discussion and conclusion It was found that pupillary dilatation caused variability and difference in the visual field parameters, which emphasizes the importance of consistent pupillary size in performing the serial automated visual field tests, especially in patients with glaucoma to allow standardized judgment on the patient’s progression.

A first investigation into the production of amorphous and nanostructured Ti-based alloys with nominal compositions Ti 41.5 Zr 41.5 Ni 17 , Ti 61 Zr 22 Ni 17 , Ti 41.5 V 41.5 Ni 17 and Ti 61 V 22 Ni 17 by mechanical alloying (MA) technique is presented. This technique was adopted to produce alloys' powders with high fresh surface area that were active for hydrogen storage. Hydrogen absorption characteristics and structure changes in the alloys after hydrogenation were investigated. Gas phase hydrogenation of the Ti–Zr–Ni alloys, at 573 K and an initial hydrogen pressure of 2 MPa, exhibited good hydriding properties and started at a maximal rate without induction period with a hydrogenation capacity up to 1.2 wt%. However, hydriding of Ti–V–Ni alloys at the same conditions exhibited slower rates. The Ti 61 V 22 Ni 17 composition showed high hydrogen absorption capacity of 1.8 wt% and exceeded 4 wt% at 345 K. In addition, the Ti–V–Ni alloys showed structure stability after hydrogenation and retained the amorphous structure.

Fabrication and processing of 99.7% purity aluminum powder reinforced with 0, 5, 10% volume fractions NiAl intermetallic metal matrix composites were conducted. The mechanically alloyed nanostructured NiAl was mixed by both regular and high energy ball milling techniques. Powders of NiAl employed for reinforcement were milled for 18 and 31 h, and therefore denoted as NiAl18 and NiAl31, respectively. The mixed powders were consolidated via a combination of cold pressing followed by hot extrusion at 480 °C for 1 h at a reduction ratio 4:1. Hardness, tensile properties, and fracture behavior of the extruded composite powders were evaluated. Structural evolution of the milled composite powders was investigated before and after extrusion using optical microscopy, field emission scanning, and transmission electron microscopy. In addition, particle type identification was carried out via energy dispersive x-ray analysis. Introducing NiAl31 (0.8 µm) enhanced the mechanical properties of the composites compared to NiAl18 (1.0 µm). Moreover, powders milling enhanced the tensile properties post hot extrusion compared to the mixed conditions due to the enhanced reinforcement distribution and bonding with the Al matrices. Hot extruded milled composite powders of Al reinforced with 10% NiAl31 produced nanostructured high-angle grain boundary structure

Background Rice (Oryza sativa L.) is one of the leading food crops of the world, the staple food of over half the world's population. The bran, which is an important byproduct obtained during rice milling, constitutes about 1/10 of the weight of the rice grain. Rice bran is the outer brown layer including the rice germ that is removed during the milling process of brown grain. This milling byproduct is reported to be high in natural vitamins and minerals, particularly vitamin E. Objectives The present study was conducted to determine the chemical composition of bran and bran oil of 13 different rice varieties commonly produced in Egypt, to study the utilization of rice bran in bread production, and to assess the quality and acceptance of the rice bran edible oil produced. Methods Rice bran was produced from 13 Egyptian varieties of recently harvested rice as well as from paddy rice stored for 1 year. The extracted bran was immediately stabilized then subjected to chemical analysis (such as moisture content, protein, fat, carbohydrates, fiber, and ash) as well as trace and heavy metals determination (P, K, Na, Ca, Fe, Zn, Cu, and Mg). Bread was produced by adding Giza172 rice bran at three different concentrations to wheat flour then subjected to chemical analysis, caloric content, and organoleptic examination. Bran oil was extracted from the different varieties of rice bran (recently harvested and stored) then subjected to chemical and organoleptic examinations as well as vitamin E and oryzanol determination. Results The percentage of rice bran of newly harvested Egyptian rice was 11.68% and was 10.97% in stored rice. The analysis showed mean values of 5.91 and 5.53% for moisture, 14.60 and 14.40% for crude protein, 14.83 and 15.20% for fat, 44.77 and 45.40% for carbohydrates, 6.55 and 7.06% for crude fiber, and 8.87 and 8.50% for ash for newly harvested and stored rice bran, respectively. Bread containing 15% rice bran showed the highest score percentages for organoleptic quality compared with the control (100% wheat flour). Rice bran oil showed higher scores of taste, smell, appearance, and texture than corn oil and sunflower oil. Conclusion Rice bran contains high nutritional components as well as phytochemicals such as vitamin E (i.e. tocopherols and tocotrienols) and the γ-oryzanol fraction that have positive effects on human health. Storage of paddy rice before milling resulted in significant effect on all studied rice bran characters and rice bran oil characters under the present investigation except crude protein and carbohydrates characters. Recommendations Substitution of wheat flour with rice bran by 15% in bread production to fortify the bread with vitamin E and to reduce the amount of imported flour is recommended.

Deriving bulk materials with ultra-high mechanical strength from nanometer-sized single metalic crystals depends on the consolidation procedure. We present an accurate molecular dynamics study to quantify microstructure responses to consolidation. Aluminum single crystals with an average size up to 10.7 nm were hydrostatically compressed at temperatures up to 900 K and pressures up to 5 GPa. The consolidated material developed an average grain size that grew exponentially with the consolidation temperature, with a growth rate dependent on the starting average grain size and the consolidation pressure. The evolution of the microstructure was accompanied by a significant reduction in the concentration of defects. The ratio of vacancies to dislocation cores decreased with the average grain size and then increased after reaching a critical average grain size. The deformation mechanisms of poly-crystalline metals can be better understood in the light of the current findings.

One of the most important casting defects in Al alloys is thought to be the double-oxide film defect (bifilm) which has been reported to have a deleterious effect on the reproducibility of the mechanical properties of Al castings. Previous research has suggested that the atmosphere inside such bifilms could be consumed by reaction with the surrounding melt, which might decrease the size of the defects and reduce their harmful effect on mechanical properties. In order to follow the change in the composition of the interior atmosphere of a bifilm, analog air bubbles were held inside Al alloy melts, for varying lengths of time, and subjected to stirring, followed by solidification. The bubble contents were then analyzed using a mass spectrometer to determine the changes in their compositions with time. The results suggested that initially oxygen and then nitrogen inside the bubble were consumed, and hydrogen dissolved in the melt diffused into the bubble. The consumption rates of O and N as well as the rate of H diffusion were dependent upon the type of oxide, which was dependent on the alloy composition. The reaction rates were the fastest with MgO (in an Al-5Mg alloy), slower with alumina (in commercial-purity Al alloy), and the slowest with MgAl2O4 spinel (in an Al-7Si-0.3Mg alloy). It was estimated that the times required for typical bifilm defects in the different alloys to lose their entire oxygen and nitrogen contents were about 345 seconds (~6 minutes), in the case of Al-5Mg; 538 seconds (~9 minutes), in the case of a commercial purity alloy; and 1509 seconds (~25 minutes), in the case of the Al-7Si-0.3Mg alloy (2L99) due to the different oxides that the different alloys would be expected to form.

Many Nanoparticles (NPs) were reported to significantly enhance the production of biogas from the anaerobic digestion of organic wastes. Herein, two types of NPs (Ni-Ferrite and Ni-Co-Ferrite) were synthesized using the co-precipitation method and characterized using X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HRTEM) with energy dispersive X-ray spectroscopy (EDS) techniques. Three different concentrations (20, 70 and 130 mg/l) of each type were added to separate biogas reactors to study their effect on the biogas production compared to blank reactor. A pressure-based biogas reactor was designed and manufactured specifically to test the effect of the NPs on the anaerobic digestion process. The pressure of the daily produced biogas was monitored using a pressure transducer and the volume of the biogas was calculated at standard conditions of pressure (1.013 bar) and temperature (15 °C). The results showed an increase in the biogas production of 6.6%, 5.9% and 32.9% upon the use of Ni-Co-Ferrite NPS at concentrations of 20, 70, and 130 mg/l compared to blank reactor, respectively. In addition, the Ni-Ferrite NPs achieved biogas enhancements of 30.8%, 28.5%, and 17.9% at concentrations of 20, 70 and 130 mg/l, respectively.

Clear understanding of the superior mechanical strength of nanometer-sized metal single crystals is required to derive advanced mechanical components retaining such superiority. Although high quality studies have been reported on nano-crystalline metals, the superiority of small single crystals has neither been fundamentally explained nor quantified to this date. Here we present a molecular dynamics study of aluminum single crystals in the size range from 4.1 nm to 40.5 nm. We show that the ultimate mechanical strength deteriorates exponentially as the single crystal size increases. The small crystals superiority is explained by their ability to continuously form vacancies and to recover them.

In the current research, mechanical alloying (MA) was employed to synthesize nanostructured Al-5.7wt.%Ni eutectic alloy through the variation of the milling parameters. Three-dimensional parametric phase diagrams were constructed for the alloy start and complete formation times over a range of ball-to-powder ratio (BPR), rotational speeds (RPM) and milling time (MT). Total energies of 224 kJkg− 1 and 1068 kJkg− 1 were necessary to trigger and complete the Al-5.7wt.%Ni eutectic alloy formation, respectively. X-ray diffraction (XRD) was employed to determine the eutectic alloy powders formation progress as a function of MT and for the investigation of the internal structural evolution in terms of crystallite sizes and lattice strain induced by milling. Prolonged milling up to 40 h of MT resulted in changes in the powder morphology and produced nanocrystalline (NC) alloy powders about 20 nm in average crystallite size. Isothermal heating (ITH) of the milled loose powders at 500 °C for 60 min using differential scanning calorimetry (DSC) was employed for the evaluation of the thermal stability produced NC structure. Alloys milled up to the alloy complete formation time at intermediate milling energies of 300 RPM and 15:1 BPR displayed relatively higher structural stability against grain growth compared to the powders milled at higher milling energies. Prolonged MT strongly influenced the morphology of the eutectic structure, which had a negative impact on the structural stability against growth during heating for both the as milled powders and the hot compact discs.

The damage mechanisms associated with the deformation and failure of high-strength Al 2139-T8 were investigated by optical and scanning electron microscopy at strain rates ranging from the quasi-static, 10^(−3) s^(−1), to the high strain rate, at approximately 2350 s^(−1). Deformation was more uniform at the lowest strain rate of 10^(−3) s^(−1), where nanocracking nucleated at coarse inclusions and clustered dispersed particles. Deformation was more localized as the strain-rate increased, with microvoid nucleation, resulting from particle-matrix interfacial decohesion and particle cracking, observed at higher strain rates. Dispersed particles and coarse inclusions were observed on the fracture surfaces of the deformed samples subjected to high rates of strain. Coarse inclusions were associated with inclusion cracking and shear deformation. The dispersed particles were associated with dimpled rupture, and the orientation of the particles determined the amount of plasticity prior to failure of the alloy.

The Nile Delta aquifer in Egypt is among the largest groundwater reservoirs in the world. This paper presents main sources causing Fe and Mn pollution to nonconventional drainage and groundwater resources and an applied method to reduce both elements to be safe. The main environmental problems were analyzed to suggest an optimum solution to be implemented in Delta District, Egypt. Raw water samples were collected and analyzed from Gharbia Governorate's study area as it represents most Delta governorates. One of the main problems related to water in Delta is the reddish colour caused by the presence of ferrous and manganese. Iron and manganese concentrations in most samples exceeded World Health Organization and Egyptian Standard for safe water limits. Iron ranges between 0.1 & 1.33, while manganese shows 0.5 & 1.45 (mg/l) in the raw water, respectively. A (GIS) model was developed to access geostatistical analyst and mapping the probability that Fe and Mn concentration exceeds a critical threshold. Results show that the main polluting sources are from chemicals and fertilizers used in fruits farms as well from petrochemical and industrial activities. Treatment process is suggested with percentage removal of Fe & Mn exceeded 92% and 96% with residual concentrations less than 0.1 and 0.05 (mg/l), respectively. These values fulfil the Egyptian guidelines for safe water requirements.

Double-oxide films (bifilms) have been held responsible for the variability in mechanical properties of aluminum castings. It has been suggested that the air entrapped inside a bifilm can react with the surrounding melt, leading to its consumption, which might improve the mechanical properties of the castings. In this work the effect of holding the melt before solidification on the distribution of mechanical properties, and by implication on entrained double oxide films, was investigated for several different aluminum alloys. The Weibull moduli of plate castings were determined under tensile conditions, and their fracture surfaces were examined for evidence of oxide films. The results suggested the occurrence of two competing mechanisms during the holding treatment: (1) the consumption of air inside the bifilms by reaction with the surrounding molten metal that may lead to improvements in mechanical properties and (2) the accompanying diffusion of hydrogen into the bifilms, which would be expected to have a deleterious effect on properties.

Nano-crystalline W-1%Y(2)O(3) (wt.%) powder was produced by a modified solution chemical reaction of ammonium paratungstate (APT) and yttrium nitrate. The precursor powder was found to consist of p ...