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Despite wide applications of noble metal-based catalysts in 5-hydroxymethylfurfural (HMF) oxidation, promoting the catalytic performance at low loading amounts still remains a significant challenge. Herein, a series of metal oxide modified MOx-Au/TiO2 (M = Fe, Co, Ni) catalysts with low Au loading amount of 0.5 wt% were synthesized. Addition of transition metal oxides promotes electron transfer and generation of the Auδ−–Ov–Ti3+ interface. A combination study reveals that the dual-active site (Auδ−-Ov-Ti3+) governs the catalytic performance of the rate-determining step, namely hydroxyl group oxidation. Auδ− site facilitates chemisorption and activation of O2 molecules. At the same time, Ov-Ti3+ site acts as the role of “killing two birds with one stone”: enhancing adsorption of both reactants, accelerating the activation and dissociation of H2O, and facilitating activation of the adsorbed O2. Besides, superoxide radicals instead of base is the active oxygen species during the rate-determining step. On this basis, a FDCA yield of 71.2% was achieved under base-free conditions, complying with the “green chemistry” principle. This work provides a new strategy for the transition metal oxides modification of Au-based catalysts, which would be constructive for the rational design of other heterogeneous catalysts.

The design of efficient and robust non-precious metal electrocatalysts towards oxygen evolution reaction (OER) is of great value for developing green energy technologies. The in-situ formed high-valence (oxy)hydroxides species during the reconstruction process of pre-catalysts are recognized as the real contributing sites for OER. However, pre-catalysts generally undergo a slow and inadequate self-reconstruction. Herein, we reported a PO43− optimized CoFe-based OER catalysts with amorphous structure, which enables a fast and deep reconstruction during the OER process. The amorphous structure induced by ligands PO43− is prone to evolution and further form active species for OER. The electron interaction between metal sites can be modulated by electron-rich PO43−, which promotes generation of high active CoOOH. Simultaneously, the etching of PO43− from the pre-catalysts during the catalytic process is in favor of accelerating the self-reconstruction. As a result, as-prepared pre-catalyst can generate high active CoOOH at a low potential of 1.4 V and achieve an in-depth reconstructed nanosheet structure with abundant OER active sites. Our work provides a promising design of pre-catalysts for realizing efficient catalysis of water oxidation.

When providing care, to protect a part of the human body against resins and plas ters for certain time, it is necessary to use a circular knitted band in cotton as a raw material. The generating of Cotton fiber fly throughout the knitting process is due to interactions of frictional surfaces with the hairiness of ring spun yarn. During the manufacture short fibers are formed in the machine device, this problem is more important with the use of cotton yarns. In this research paper, the short fibers formation on circular knitting machines from spun yarns such as cotton is investigated The knitting conditions consist of; yarn tension, yarn feeding speed and the angle contact of the yarn with guides and needles. The results obtained illustrate the effect of yarn tension on the short fibers deposit caused by the combination of yarn friction with the knitting elements.

Biodegradable polymer berbahan dasar pati merupakan alternatif polymer ramah lingkungan yang dikembangkan untuk mengatasi permasalahan yang ditimbulkan oleh bahan – bahan polymer sekali pakai berbahan dasar minyak bumi . Biodegradable polymer dengan bahan dasar pati memiliki kelemahan antara lain nilai water vapor permeability dan water absorption nya yang besar serta nilai kuat tarik nya yang kecil. Kajian literatur ini bertujuan untuk mengetahui pengaruh filler dan coating beeswax terhadap karakteristik biodegradable polymer berdasarkan penelitian yang sudah dilakukan. Berdasarkan jurnal yang didapat pengaplikasian coating beeswax dapat menurunkan nilai water absorption lebih baik dari biodegradable polymer tanpa coating . Penelitian dengan menggunakan filler tanpa coating beeswax menghasilkan nilai water absorption sebesar 15,77% dengan bahan baku pati singkong. Penelitian menggunakan coating beeswax menghasilkan nilai water absorption sebesar 0,8%. Penelitian dengan coating beeswax menghasilkan nilai water vapor permeability sebesar 4,4042 x 10 -9 g mm/s m 2 Pa. Pada pengujian kuat tarik dengan menggunakan filler tanpa coating beeswax menghasilkan nilai kuat tarik sebesar 20 MPa. Penelitian menggunakan coating beeswax menghasilkan nilai kuat tarik terbaik yaitu 14 MPa.

The loading strategy of cocatalysts affects its activity exerting and atom utilization. Here, a novel strategy for loading precious metal (Pt) cocatalysts by means of ultrathin N-doped carbon layer is reported. The strategy is based on a pyrolysis process of predesigned N-containing polymers and Pt complexes on hard-template surface, during which Pt can be reduced by carbon from pyrolysis at high temperatures. Finally, the hollow TiO2 composite with stable and dispersed Pt on its inner surface was prepared. It shows an ultrahigh photocatalytic H2 production activity as high as 25.7 mmol h−1 g−1 with methanol as sacrificial regent, and displays an apparent quantum yield as 13.2%. The improved photocatalytic activity and stability can be attributed to the highly dispersed and ultrafine Pt nanoparticles, enhanced interaction between Pt-species and carbon support, fast photo-excited electron transport from the high graphitization degree of NC layers, ample oxygen vacancies/defects, as well as the manipulated local charge distribution of Pt/NC-layer configuration. Additionally, the universality of the proposed strategy was demonstrated by replacing metal sources (such as, Ru and Pd). This work presented a promising strategy for the design and development of novel photocatalysts, which shows a broad application prospect.

Electrochemical CO2 reduction (CO2RR) over molecular catalysts is a paramount approach for CO2 conversion to CO. Herein, we report a novel phthalocyanine-derived catalyst synthesized by a two-step method with a much improved electroconductivity. Furthermore, the catalyst contains both Ni–N4 sites and highly dispersed metallic Ni nanoclusters, leading to an increased CO2RR currents by two folds. Isotope labelling study and in situ spectroscopic analysis demonstrate that the existence of metallic Ni nanoclusters is the key factor for the activity enhancement and can shift the CO2RR mechanism from being electron transfer (ET)-limited (forming ∗COO−) to concerted proton-electron transfer (CPET)-limited (forming CO).

This work includes fabrication and electrical characterization of Metal/Interlayer/Semiconductor (MIS) structures with methyl violet organic film on p-InP wafer. Metal(Ag)/ Interlayer (methyl violet =MV)/Semiconductor(p-InP) MIS structure presents a rectifying contact behavior. The values of ideality factor (n) and barrier height (BH) for the Ag/MV/p-InP MIS diode by using the current-voltage (I-V) measurement have been extracted as 1.21 and 0.84 eV, respectively. It was seen that the BH value of 0.84 eV calculated for the Ag/MV/p-InP MIS structure was significantly higher than the value of 0.64 eV of Ag/p-InP control contact. This situation was ascribed to the fact that the MV organic interlayer increased the effective barrier height by influencing the space charge region of inorganic semiconductor. The values of diffusion potential and barrier height for the Ag/MV/p-InP MIS diode by using the capacitance-voltage (C-V) measurement have been extracted as 1.21 V and 0.84 eV, respectively. The interface-state density of the Ag/MV/p-InP structure was seen to change from 2.57×1013 eV-1cm-2 to 2.19×1012 eV-1cm-2.

Green rusts with brucite-like layers of hydroxide intercalated with anions constitute a family of diverse precursors for the synthesis of iron oxides via dehydration, but precise structural control of the resulting oxides with respect to the size and shape at the nanometer level remains challenging due to the easy oxidation of the ferrous species. Herein, we report a new synthetic strategy for the facile preparation of fibrous-like green rusts by using appropriate balancing anions (CO32− and SO42−) in ethylene glycol to regulate the morphology. Depending on the type of the intercalating anion, the green rusts were converted into hematite with fibrous- or plate-like shapes upon thermal activation. When evaluated in the reaction of NO reduction by CO, these iron oxides showed a prominent shape-dependent catalytic behavior. The fibrous-like Fe2O3 was much more catalytically active and structurally robust than the plate-like analogue. Combined spectroscopic and microscopic characterizations on the nanostructured iron oxides revealed that the superior performance of the fibrous-like Fe2O3 stemmed from a facile Fe2O3/Fe3O4 redox cycle and a higher density of active sites for NO activation.

Mg alloys are considered the most promising engineering materials because of their unique properties. However, the uncontrolled corrosion rate of these alloys limits their applications. Therefore, in this study, a micro-arc oxidation layer was used as a transition layer to “directly” grow a zinc-based metal-organic framework (MOF) composite coating on the surface of a Mg alloy (AZ91D). Herein, the two zeolitic imidazolate framework (ZIF-8) coatings with different morphologies were separately prepared by homologous metal oxide induction and a one-step in-situ growth method. The superhydrophobic composite coating showed strong hydrophobicity and self-cleaning properties, which could prevent the penetration of water and corrosive ions (Cl−) into the surface of AZ91D. Electrochemical tests demonstrated that the super-hydrophobic composite coatings greatly enhanced the corrosion resistance of AZ91D, and the corrosion current density decreased from 10−5 to 10−9 A/cm2. These results indicate that the ZIF-8 coatings are beneficial for improving the hydrophobicity and enhancing the corrosion resistance of Mg alloys. Therefore, MOF composite coatings provide a new strategy that can be used to prepare multifunctional anticorrosion coatings on metal substrates.

Converting CO2 to valuable materials is attractive in environmental protection and resource utilization. In this study, a vapor–liquid interface reaction system for mass production of high-quality graphene is reported. The graphene obtained has high crystallinity and few defects during the reaction of CO2 and Mg melt. The growth mechanism of graphene is demonstrated in vapor–liquid interface area by combining the CO2 bubbles as a soft template to guide growth with the confinement effect of dense MgO nanoparticles. The quality of the graphene is verified by epoxy composites with high electromagnetic shielding effectiveness. Additionally, the V–L reaction method ingeniously solves the dispersion of graphene in metal, providing a preparation strategy of Mg matrix composites with structure and function integration.

Translucent zirconias have been developed with better esthetics than high-strength zirconias by reducing opacity. However, studies on their translucency and strength are sparse.The purpose of this in vitro study was to compare the relationship between translucency and biaxial flexural strength of recently developed high-translucency zirconia, high-strength zirconia, and lithium disilicate ceramics.Disks (n=12) were fabricated for 5 ceramic materials: high-strength zirconia (BruxZir 16 shaded), translucent zirconia (BruxZir Anterior shaded, Katana UTML, Katana STML), and lithium disilicate (IPS e.max, Press HT, and LT). A standard tessellation language (STL) file was designed, and the specimen milled, finished, and glazed according to manufacturer's instructions for each material. The translucency parameter was calculated against black and white backgrounds and white and stump shade with ND4 background by using a spectrophotometer. Biaxial flexural strength was calculated by using the 3-ball test. The load was applied at a crosshead speed of 0.5 mm/min with a 49-N load cell until failure occurred. Translucency parameter and biaxial flexural strength data were analyzed with 1-way analysis of variance (ANOVA). A Tukey honest significant difference multiple comparison test was used to determine significant differences (α=.05).The IPS e.max HT was more translucent against both backgrounds (32.85 for black/white and 15.34 for white/stump), while BruxZir 16 was the least translucent (19.78 for B/W and 8.83 for W/S). All groups tested differed in translucency (P.001) except for BruxZir Anterior and Katana STML, which were not significantly different (P=.052). For biaxial flexural strength, BruxZir 16 had the highest strength (995.44 MPa) and e.max HT, the lowest (186.75 MPa). No significant differences were found between BruxZir anterior and Katana STML, Katana UTML and IPS e.max LT, or IPS e.max LT and IPS e.max HT (P.05). Translucency parameter values using both backgrounds were strongly correlated (r=0.99). However, biaxial flexural strength values were inversely related to translucency parameter values when using black/white and white/stump shade but with high correlation (r=-0.777 and -0.756 respectively).Lithium disilicate was the most translucent and yet the weakest material, whereas high-strength zirconia was the most opaque ceramic and the strongest. Katana UTML had the highest translucency but was weakest among translucent and high-strength zirconia materials. Overall, translucency was negatively correlated with biaxial flexural strength.

Results of fourteen two-span continuous deep beams those made from ordinary reinforced concrete (ORC) as a reference and rubberized reinforced concrete (RRC) are presented and discussed in this research. The main parameters are the rubber ratios as a replacement with coarse and fine aggregate and shear span/depth ratio (a/h) is 1.33 and 1.66. Chip and crumb rubbers were used to replace coarse and fine aggregate respectively in four different amounts by volume (5%, 10%, 15%, and 20%). The proposed mix shows an ability to replace 20% of the aggregate (coarse or fine), and the production is still structural concrete. All beams design to fail in shear. The main crack is formatted between the intermediate support and the applied load diagonally. In spite of the inclusion of waste tire rubber in concrete has specific apparent degradations, the potential benefit seems to overlook the adverse effects and also provides the primary significant value of resolution for rubber waste problems. The results show that 20% volumetric substitution of natural coarse or fine aggregates with tier rubber reduced the ultimate load of continuous deep beams by 32.06% and 32.65% but significantly increases the ultimate deflection by 83.07% and 106.28% respectively. The ductility of rubberized continuous deep beams increases up to 36.95% when the replacement ratio of crumb rubber is 20%.

This paper assesses the possibility of utilisation of clay–waste tyre rubber mixes as construction materials for geotechnical structures. Rubber granulates (Rg) and rubber fibres (Rf) were blended with 2.5, 5, 7.5 and 10% clay content. The various combinations of clay–rubber granulates (CRg) and clay–rubber fibres (CRf) were subjected to the sequence of compaction, strength, consolidation and swelling pressure tests. A linear decrementing trend of compaction parameters was observed with an increase in Rg and Rf contents. An insignificant rise in unconfined compressive strength (UCS) and splitting tensile strength (STS) of clay was observed with the addition of Rg and Rf up to 5 and 2.5%, respectively. Higher inclusions had reduced the UCS and STS of clay. However, a continual increase in failure strain was observed with an increase in Rg and Rf contents. The compression index of CRg and CRf mixtures was found to increase with the increase of Rg and Rf contents. A continuous decrease in the soaked California bearing ratio and swelling pressure (σs) of CRg and CRf mixtures was observed with the increase in Rg and Rf contents. In view of code requirements, the pre-requisite treatment of CRg and CRf mixtures should be carried out before field applications.

RE-containing magnesium alloys were prepared via molten-salt-mediated magnesiothermic reduction by using RE2O3 (RE=Y, Nd and Gd) and Mg metal as raw materials. The thermomechanical analysis of the magnesiothermic reduction reactions in molten salt was investigated. Then the molten-salt-mediated magnesiothermic reduction process was studied from three different perspectives. After that, the RE-containing magnesium alloy was characterized by using chemical analysis, XRD analysis and SEM analysis. The magnesiothermic reduction was a liquid-liquid reaction with relatively weak driving force. During the melting process and the magnesiothermic reduction process, magnesium metal and the obtained alloy went up and down as a whole in molten salt, which improved the process safety without introducing chloride inclusions. Meanwhile, the hydrolysis of the RECl3-containing molten salt occurred at elevated temperature, which severely impeded the magnesiothermic reduction process. After the magnesiothermic reduction at 750 °C for 2.0 h, the content of RE and the common impurity elements in the obtained RE-containing alloy met the both requirements of the commercial WE43A and WE43B.

PURPOSE To evaluate the effect of cavity tapering on the marginal and internal adaptation of endocrowns fabricated from two different ceramic materials. MATERIALS AND METHODS Two mandibular molar model teeth were prepared with two different cavity tapers (5 and 10 degrees). Forty endocrowns in four groups (n = 10 each) were milled using lithium disilicate and zirconiareinforced lithium silicate ceramics for each cavity taper. The marginal and internal adaptation were measured with a stereomicroscope (×30) at 18 different points. The data were statistically analyzed using independent t test (P < .05). RESULTS A statistically significant difference was shown among the tested groups at 10 degrees of taper (P < .001). At 5 degrees of taper, the difference was insignificant. The greatest internal gap was observed on the pulpal floor in all tested groups. CONCLUSION All materials had clinically acceptable internal and marginal gaps; however, lithium disilicate ceramic had significantly better adaptation at 10 degrees of taper.

In this study, CO₂ conversion to acetate and CH₄ was achieved in a flow-through laboratory-scale microbial electrosynthesis (MES) cell composed of a 3D conductive polylactic acid (cPLA) lattice cathode with electrodeposited metal electrocatalyst coatings. The MES cell with a bare cPLA cathode showed the poorest performance with the lowest H₂ and CH₄ production rates and low Coulombic efficiency. This was ascribed to a poor electrocatalytic activity of cPLA towards H₂ production and high electrode resistivity. When the cPLA electrode was modified with metal coatings, the CH₄, acetate and H₂ production rate increased significantly, with the following trend: cPLA < Ni < NiFe < NiFeMn. The better performance of the metal-coated cPLA in terms of CH₄ production was attributed to the lower electrical resistance, enhanced H₂ production and enhanced electron transfer between the cathode and the biofilm. At the cell potential of 2.8 V, the best-performing NiFeMn cPLA cathode showed stable production of CH₄ (50 ± 6 mL d⁻¹), acetate (185 ± 27 mg d⁻¹), and H₂ (545 ± 175 mL d⁻¹) at close to 100% Coulombic efficiency.

This highlight is the second installment of a series of highlights on nonprecious-metal-catalyzed reactions of interest to the pharmaceutical industry. Selected transformations from March to June 2...

Cold metal transfer arc additive manufacturing technique was used to produce 5356 aluminum alloy by adding refining agents to solve the problems of coarse grains and poor performance. Metallic powd...

The objective of this study was to evaluate the bond behaviour of concrete-filled steel tubes (CFSTs) where waste chipped rubber, sourced from scrap tyres, partially replaces natural coarse aggregate. A series of push-out tests on 112 circular and square CFST specimens were investigated with the main parameters considered in the tests being: (a) cross-sectional type (circular and square); (b) cross-sectional dimensions; (c) concrete type (normal and rubberised concretes); (d) replacement ratio of recycled chipped rubber; and (e) concrete age (28–365 days). Four rubber chip replacement ratios (0, 10, 20 and 30%) by volume of coarse aggregate were used. The experimental results indicated that cross-sectional type and dimensions have a high impact on the interfacial bond strength. The bond strength in larger circular tubes was about 60% more than the bond strength in smaller circular tubes, and about 127% and 42% more than the bond strength in large and small square tubes, respectively. It was also found that CFSTs incorporating chipped rubber shared a generally similar interface bond behaviour between the concrete core and steel tubes with conventional CFSTs. Moreover, the bond strength decreased remarkably with the increase of concrete age.

Retrofitting a crown to an existing removable partial denture (RPD) is a complex process and requires additional clinical and laboratory procedures. Various methods have been described for retrofitting a new tooth-supported crown. However, if an abutment tooth has to be extracted, descriptions of techniques for restoring a new edentulous site with an implant-supported crown retrofitted to an existing RPD are lacking. Therefore, this technical report describes a straightforward approach to fabricating an implant-supported surveyed crown fitted to an existing RPD by using an acrylic resin template.

Biodegradable magnesium (Mg) and its alloy show huge potential as temporary bone substitute due to the favorable biocompatibility and mechanical compatibility. However, one issue deserves attention is the too fast degradation. In this work, mesoporous bioglass (MBG) with high pore volume (0.59 cc/g) and huge specific surface area (110.78 m2/g) was synthesized using improved sol-gel method, and introduced into Mg-based composite via laser additive manufacturing. Immersion tests showed that the incorporated MBG served as powerful adsorption sites, which promoted the in-situ deposition of apatite by successively adsorbing Ca2+ and HPO42−. Such dense apatite film acted as an efficient protection layer and enhanced the corrosion resistance of Mg matrix, which was proved by the electrochemical impedance spectroscopy measurements. Thereby, Mg based composite showed a significantly decreased degradation rate of 0.31 mm/year. Furthermore, MBG also improved the mechanical properties as well as cell behavior. This work highlighted the advantages of MBG in the fabrication of Mg-based implant with enhanced overall performance for orthopedic application.

The recent discoveries of many metal superhydrides provide a new route to room-temperature superconductors. However, their stability and structure trends and the large chemical driving force needed to dissociate H2 molecules and form H covalent network cannot be explained by direct metal-hydrogen bonds and volume effect. Here, we demonstrate that the understanding of superhydrides formation needs a perspective beyond traditional chemical bond theory. Using high-throughput calculations, we show that, after removing H atoms, the remaining metal lattices exhibit large electron localization at the interstitial regions, which matches excellently to the H lattice like a template. Furthermore, H lattices consist of 3D aromatic building units that are greatly stabilized by chemical templates of metals close to s-d border. The chemical template theory can naturally explain the stability and structure trends of superhydrides and help to predict new materials such as two-metal superhydrides.

The disposal of metal plating sludge (PS) to landfills is an increasingly common practice in developed and developing countries. This paper presents a novel PS stabilisation technique using fly ash (FA)-based geopolymers as a waste management option. Strength and microstructural evaluations were carried out on PS-FA geopolymers at various values of factors, including liquid alkaline activator (L = sodium silicate (Na2SiO3)/sodium hydroxide (NaOH) ratio), L/FA ratios, FA/PS ratios and curing time. Increasing the amount of PS in PS-FA geopolymers reduced the total porosity, subsequently resulting in higher unconfined compressive strength (UCS) values. The main geopolymerisation product of the FA-based geopolymer was sodium aluminosilicate hydrate (N-A-S-H) gel. Since PS had a high calcium content, it would react with the high amount of silica and alumina present in FA to generate calcium aluminosilicate hydrate (C-A-S-H) gel in PS-FA geopolymers. This C-A-S-H gel coexisted with the N-A-S-H gel from FA-based geopolymers and hence significantly accelerated UCS development of PS-FA geopolymers over time. The UCS values of PS-FA geopolymers were found to meet the US Environmental Protection Agency requirement for disposal to landfills. The outcomes from this research can be translated into a regulatory framework for managing PS and diverting this industrial waste from landfills.

A mesoporous UiO-66-NH2 aerogel is prepared via a straightforward sol-gel method without using any binders or mechanical pressures, in which the amine groups are directly introduced into the matrix by using 2-aminoterephthalic acid. The novel UiO-66-NH2 aerogel also exhibits high specific surface area and mesopore-dominated structure, implying its highly potential use in CO2 adsorption. For ulteriorly investigating the effect of amine loading on the CO2 adsorption ability, a series of UiO-66-NH2 aerogel with different amino content is fabricated by changing the ligand/metal molar ratio. When the molar ratio is 1.45, the CO2 adsorption capacity reaches the optimum value of 2.13 mmol·g–1 at 25 °C and 0.1 MPa, which is 12.2% higher than that of pure UiO-66 aerogel. Additionally, UiO-66-NH2-1.45 aerogel also has noticeable CO2 selectivity against N2 and CH4 as well as good regeneration stability. Such results imply that it has good application prospect in the field of CO2 adsorption, and also contains the potential to be applied in catalysis, separation and other fields.

This paper describes a statistical and mathematical approach to optimize the mechanical properties of a wood plastic composite with Polyethylene Terephthalate (PET) as polymeric matrix. Wood plastic composite are materials that consist of a primary continuous polymer phase, where a secondary filler dispersed phase is embedded, the filler generally is wood fibers or sawdust. The slack variable approach in mixture experiments, consist in selecting a component of the mixture as slack variable, to subsequently design and analyze the experiment in terms of the remaining components. With the experimental design information three slack variable model were fit. Using response surface graphs, we show how different compositions modify the mechanical properties of wood plastic composite. Besides, by the desirability function, the optimal formulation of the compound that simultaneously maximizing the mechanical properties of wood plastic composite, was obtained. Finally, the components proportions that provides the best tensile, flexural and compression strength are presented.

Waste management has become a new challenge for the construction industries since rapid urbanization is taking place worldwide. Ceramic waste is one such material which is being originated from construction sites and industries, imposing a significant risk to the environment due to its non-biodegradable nature. With the goal of waste utilization, this study aims to predict the compressive and splitting tensile strength of concrete made with waste Coarse Ceramic aggregate (CCA) and Nylon Fiber (NF) by using two distinct machine learning algorithms, namely, Support Vector Machine (SVM) and Gradient Boosting Machine (GBM). A comprehensive data set for testing and training the models containing 162 records of compressive and splitting tensile strength test results were considered from nine mix proportions. For training the dataset, parameters like cement content, sand content, stone content, ceramic content, nylon fiber content, curing duration, and concrete strength were taken as input variables. The predicted strengths obtained from the SVM and GBM based models are found to be in close agreement with the experimental results. In terms of coefficient of determination (R2), GBM showed significantly better result for both compressive strength (e.g., SVM Overall R2 = 0.879 & GBM Overall R2 = 0.981) and tensile strength (e.g., SVM Overall R2 = 0.706 & GBM Overall R2 = 0.923) prediction. Furthermore, based on the statistical accuracy measures like the mean absolute error (MAE), mean square error (MSE), root mean square error (RMSE), it has been observed that GBM has yielded much better performance compared to SVM in predicting the mechanical strength of concrete.

The mechanical properties of two commercial epoxides have been investigated in both unfilled and filled with varying the weight fraction of Nano Aluminum powder and Nano Aluminum with Nano Titanium powder. The values of Young’s modulus, modulus of rigidity, yield stress, tensile strength, flexural strength have been studied at room temperature to identify the specific influence of Aluminum powder (the particle size for Aluminum powder is less than or equal to 50 nm (d ≤ 50). The weight fraction has different values (equals to 10%, 20% and 30%), and Nano Aluminum with Nano Titanium powder for Aluminum powder, the particle size (d) is less than or equal to 50 nm (d ≤ 50). The weight fraction has different values (equals to 10%, 20% and 30%). Also for Titanium powder, the particle size is less than or equal to 50 nm (d ≤ 50), and the weight fraction is 1% for each different weight fractions of Aluminum powder to epoxy resin. The experimental results obtained from laboratory have been analyzed in order to achieve the best result. It is concluded that Young’s modulus and modulus of rigidity increase when the weight fraction for Nano Aluminum powder and Nano Aluminum with Nano Titanium powder increase.

Anatomic-contour zirconia prostheses are usually cemented with resin cement. However, information regarding the effects of the zirconia shade and thicknesses on the translucency of the prosthesis, the intensity of the transmitted light beneath the prosthesis, and the subsequent degree of conversion in the resin cement is sparse.The purpose of this in vitro study was to investigate the translucency parameter in 3 anatomic-contour zirconia specimens of 2 shades at 5 different thicknesses and to investigate the transmitted light intensity and degree of conversion of the resin cement beneath the ceramic specimens by using a traditional zirconia and a lithium disilicate glass ceramic as controls.Ceramic specimens from 1 anatomic-contour zirconia in a generic shade (CAP FZ) and 2 anatomic-contour zirconias in A2 shade (Zirlux and Luxisse) were used. Lithium disilicate in HT A2 shade (IPS e.max CAD) and traditional zirconia in a generic shade (CAP QZ) were used as controls. A total of 125 ceramic specimens (n=25) were fabricated to a final specimen dimension of 12×12 mm and in thicknesses of 1.0, 1.25, 1.5, 1.75, and 2.0 mm according to the manufacturers' recommendations. The CIELab color space for all specimens placed against a white and black ground was measured with a spectrophotometer (CM-2600D), and the translucency parameters were calculated for the materials at various thicknesses. A light-polymerizing unit (DEMI LED) was used to polymerize the resin cement (Variolink II) placed beneath the ceramic specimens. Transmitted light intensity from the polymerization unit beneath the ceramic specimens was measured by using a spectrophotometer (MARC Resin Calibrator), and the transmittance of each specimen was calculated. The coefficient of absorption of each material was calculated from the regression analysis between the natural log of transmittance and specimen thickness. The degree of conversion of resin cement was measured by using a Fourier transformation infrared (FTIR) spectrophotometer. The results were analyzed by using 2-way ANOVA (α=.05). The relationship between the transmittance and the translucency parameter was evaluated by plotting the transmittance against the translucency parameter value of each specimen.The translucency parameter decreased with increasing thickness in all 5 material groups. All anatomic-contour zirconia had lower translucency parameters than e-max CAD (P.001). The same results were found for the intensity of the transmitted light (P.001). Both A2 shade anatomic-contour zirconia (Zirlux and Luxisse) showed significantly lower light transmittance than a generic shade anatomic-contour zirconia (CAP FZ) (P.001). The coefficients of absorption were found to range from 0.63 to 1.72 mmThe translucency parameter and the transmitted light intensity of ceramic material were influenced by the type of ceramic and the shade and thickness of the ceramic. The combined effects of layer thickness and the intensity of the transmitted light in the A2 shade anatomic-contour zirconia (Zirlux and Luxisse) resulted in a lower degree of conversion in resin cement than in a generic shade anatomic-contour zirconia (CAP FZ) at layer thicknesses of 1.75 and 2 mm.

A typical conversion process of a complete-arch immediate loading protocol entails preparing holes in a complete denture for connection to interim copings, which reduces the strength of the prosthesis. The excellent mechanical properties of milled polymethyl methacrylate (PMMA) disks may provide interim prostheses with improved strength.The purpose of this in vitro study was to measure the flexural strength and failure load of simulated acrylic resin immediate implant-supported interim prostheses fabricated by conventional processing and computer-aided manufacturing.A master patient model was created with an acrylic resin base and 2 BioHorizons Internal 4.5-mm-diameter implants placed with a 21.5-mm span and multiunit abutments (MUA) tightened to place. Two groups with different prosthodontic designs were used: one represented the standard fixed prosthesis with support at each end (noncantilever, NC), and the other group represented the cantilever portion of the prosthesis (cantilever, C). Two connection designs of prosthesis blocks to MUA abutments were evaluated: one with typical holes in the prosthesis for capturing interim copings and one with a low-profile coping. For the heat-processed PMMA groups (HP/NC and HP/C), wax patterns were milled, and heat-polymerized denture base PMMA prostheses were processed. The milled PMMA groups (M/NC and M/C) were milled from a tooth-shaded PMMA disk for the prosthesis blocks. The milled low-profile groups (Mlp/NC and Mlp/C) had identical dimensions except that connection to the low-profile coping was designed with a cement space and a narrow diameter screw access hole and was milled from a PMMA disk. The failure load (N) of the cantilever prostheses was recorded, and for NC groups, the 3-point flexural strength formula (MPa) was calculated. The Weibull modulus, characteristic strength, and summary statistics were computed, and the groups were statistically analyzed with ANOVA and the post hoc Tukey test (α=.05).The mean flexural strengths (MPa) were HP/NC=91.35 ±18.92; M/NC=143.94 ±36.79; Mlp/NC=117.06 ±13.86. Significant differences were found among groups (P.001). Mean failure loads (N) and Weibull modulus (WM) of cantilever prosthesis strengths were for HP/C=512.66, WM=5.597; M/C=695.06, WM=4.875; Mlp/C=254.97, WM=1.797 (P.001).Implant fixed interim structures milled from high-density PMMA blanks had a 35% higher flexural strength for both the standard prostheses and the cantilever prostheses than heat-processed denture base PMMA. The low-profile coping design was stronger than the heat-processed material, and the failure point was relocated from the lateral walls to the cervical margin area.

In the recent studies additive manufacturing technology prove their importance in every field because of its accessibility increases as the earlier patents expired which gives an opportunity to the manufacturers to develop different types of 3D printing devices as per need. There are different types of material available in the market and for every type of material we need an additive manufacturing method to print these materials layer by layer on top of each other by using 3D CAD models (Mazzanti et al., 2019). In this paper we discusses wide range of materials in details with respective 3D printing techniques. Further materials which are most commonly used such as polymers, metals and alloys, composites, concrete, ceramics to the materials which are under development stages such as biomaterials, food printing materials, smart materials, glass, resin and wood are discussed in detail with their respective 3D printing methods. The scope of 3D printing in the suggested areas are concluded.

In the Internet of Things (IoT) the physical objects network is described as “things” linked to sensors, software and other technologies to connect and share information through the Internet with other devices and systems. The floods lead to large losses of life and property in several countries. However, the absence of sufficient technology results in further death and property losses as a result of flooding in developed countries. This is because of a lack of flood alert systems. The objective of this paper is to monitor the flood situation and provide a text message warning in the event of a threat. The main aim of this paper is to detect rising river water levels at a safe distance away from the railways and to allow the respective authorities to take appropriate measures by means of SMS. A sensor is a system that senses and reacts to certain physical data. The 8051 microcontrollers were produced by Intel in 1981. The microcontroller is 8-bit. It has 40 DIP pins, 4 kb of ROM stores and 128 bytes of RAM and two timers and 16 bits. It is equipped with 2 timers. There are four parallel 8-bit ports that are programmable and adjustable as necessary. The hardware device that uses GSM mobile technology for the provision of an information link with a remote network is a GSM modem or a GSM module. A float switch is a level sensor type, a fluid control system that is used inside a tank. A condenser is a tool that stores electrical energy in an electric field. It's a passive electronic feature with two terminals. A LED is a semiconductor light source that transmits light through the flowing current. Liquid Crystal Display stands for LCD. It is a thin, flat display device used in a variety of electronics. A digital electronic level shifter is a system used in the transformation of signs from one logic or voltage domain to another, also known as logic level shifter or voltage level Translation. A diode is an electronic component with a two-terminal that mainly conducts current in one direction, with low resistance and high resistance in one direction. The aim of this paper is to detect early Flood and give early warnings to Needy people.

Nowadays, environmental sustainability is the responsible of engineering community for which the usage of waste or recycling is essential towards ecological sustainability, for which green materials are considered widely in all sectors. Because of the significance of characteristic filler supported composites in the advancement of lightweight materials, this research exploration centers around utilizing biodegradable garbage such as used tea dust powder reduces the impact of environmental pollution. In this study, effect of organic residue, tea dust is effectively recycled/utilized for fabricating polymer composite to find its suitability in engineering applications. Epoxy polymer is considered as matrix material and different volume fractions of used tea dust powders (10, 20, 30, 40, 50, and 60 vol%) are used as reinforcement. Hand-layup approach is adopted for fabricating the polymer composite and the samples are tested for their mechanical properties viz., impact, flexural and tensile strength. Based on the mechanical strength the best combination is found to be 40% vol. in epoxy matrix; higher addition than 40% reduces the strength due to lower bonding between the powders and matrix.

In this technical world, the properties and internal structure of materials renders a vital part in building up of the components for various specific purposes and improvise their efficiencies in a better way. The combination of copper with other metals is always an interesting one. In this, brass of grade BS90 is an alloy of zinc added with copper and it is lustrous in nature. The amount of zinc that is mixed with copper can be varied to develop different categories of brass with different melting temperatures that develops distinct electrical and mechanical potency. In the process of better understanding of the powder metallurgy technique and analyzing and improvising the properties of brass, this research is carried out. Primarily, this process is carried out based on the powder metallurgy technique. The prime intention of this investigation is to develop and process the specimens under predetermined conditions of powder metallurgy and then their mechanical hardness and the microstructure are to be characterized. The secondary objective is to analyze these characteristic values and compare them relatively to the specified conditions.

The transparent relaxor ferroelectric ceramics of the system lanthanum modified lead magnesium niobate (PLMN-13PT) have been investigated for a variety of electro-optic, properties; good electro-optic switching times and modest half-wave voltages. In this work, the dependence of microstructural, structural, dielectrical, optical, and electro-optical properties in function of Rare Earth (RE = Tm3+, Nd3+, Yb3+, Er3+ and Ho3+) has been reported. PLMN-13PT:RE with excellent properties were obtained, highlighting the electrical, optical, and electrooptical properties, suitable for the fabrication of multifunctional devices. The most prominent or important feature is the largest quadratic Electro-optic coefficient achieved ((9.37 ± 0.39) × 10−16 m2/V2) corresponding to PLMN-13PT:Ho transparent ceramics. This result in addition to the electrical and photoluminescence properties becomes a promising alternative to building multifunctional devices.

The goal of this experiment is to investigate the effect of laser engraving parameters on Al 6063 aluminum alloy specimens using a fiber laser engraving equipment. The experimental design makes use of Taguchi's L16 orthogonal array. Surface roughness and engraving depth are the responses which are to be optimum for machining process parameters such as fill spacing, power, frequency, and scan speed. Using regression analysis, the mathematical models for individual responses were created. Grey relational analysis coupled with the Taguchi technique has been presented for simultaneous response optimization. The optimal setting parameters for multiple performance characteristics is fill spacing at level-3, power at level-4, frequency at level-2 and scan speed at level-4 i.e., FS3-P4-F2-SS4. To determine the significance of the models, the Analysis of Variance (ANOVA) approach is used. Finally, in the confirmation test, it is observed that the grey relational grade is improved from the initial process parameter combination.

Light metals such as aluminum alloys which are being broadly used in automobile sideways, aerospace production as well as segments in military. A light-weight metals prominent for energy consume reduction, efficiency of gasoline and oil increment and superior security to environment. The main utilization of aluminum matrix alloy components have been manufactured by the appropriate behaviors of high tensile strength, hardness, decent machinability, great cast-ability and excessive resistance of corrosion. In the present investigation dealing with casting and heat treatment processes of aluminum alloys 6063 by two different methods such as Sand casting and Die casting. The characterization of AA6063 are analyzed with help of destructive and non-destructive techniques. Finally the results indicates that die casted material gives better results when it is heat treated than the sand casted material.

This research aims to examine HAMC’s tribology’s performance-[Hybrid Aluminium metal matrix composites] reinforced with Silicon carbide, Nickel & Graphite at different temperature conditions for thermal applications. This is highly significant for applications with high-temperature. The HAMCs were developed by stir casting method by reinforcing particles like SiC (5% & 10%) and Ni.-Gr. (2% fixed) into LM26 aluminium alloy. The wear rate and friction coefficient of the material is analyzed through pin-on-disc apparatus. The parameter impact on applied load, wt%, sliding distance, and the temperature is analyzed using an L9 orthogonal array. COF and wear loss of the proposed HAMC is determined using the ANOVA method. The Tribological property of HAMC is mainly influenced by applied load and temperature. The varying hybrid % controls the COF and wear loss. The SEM analysis is used to assist the performance of the worn surface.

Through quantitative statistics and morphological characterization of ceramic fragments for ceramic composite bulletproof insert plates (CCBIPs), distribution characteristics of ceramic fragments within a specific size range were analyzed for different Armor Piercing Incendiary (API) and shot times. To quantitatively evaluate the effect of energy absorption for ceramic plates, a model of energy absorption during penetration for CCBIPs was established based on statistics of the size distribution of ceramic fragments (SDCF). Variation in the SDCF and its influence on energy absorption for CCBIPs were investigated. The results indicate that the distribution feature of ceramic fragments in the range of 0.25–2.25 mm is Gaussian distribution. Compared with Type 56 of API (56-API), ceramic fragments formed by 53-API with higher kinetic energy possess more quantity and more concentrated distribution, whose average equivalence size decreases by 6.5%, corresponding to increasing by 83.9% of estimated energy absorption. Besides, the ability of CCBIPs to resist the third shot is significantly weakened, whose estimated energy absorption decreases by 58.8% compared with the first shot. More concentrated distribution and fewer fragments are formed after the third shot, the average equivalence size of ceramic fragments increases by 6.9%, which may attribute to the micro-cracks induced by the previous two shots.

The article studies Automatic Oil Spraying Machine design and manufacture for baking device. In a current baking process, the workers manually spray the oil onto the trays. The spraying cycle increases the cost of man power in small scale industries. An automated oil spraying system is designed to solve these issues, where they can automatically spray the oil on the baking tray easily and effectively. The main components of this device are the mechanical and electrical components. The mechanical portion consists of conveyor belt, roller, bearing, gear, nozzle and tank, and mechanical structure. The electrical components include the IR sensor module, the dc motor, the dc pump, Arduino, and the source of the batteries. The key advantages of this approach are high precision oil spraying; improve efficiency, cost reduction and manpower. This model system's gross weight contains 15 kg (roughly). The efficiency of this device is checked for product production under different working conditions to track the performance of the work and the time durations.

The expansive soil has serious impact due to its unstable volumetric behaviour when it undergoes seasonal variations. In order to utilise the problematic expansive soil for any kind of work it needs to alter the behaviour of soil by stabilisation using addition of admixtures. From the economical point of view using industrial waste materials is the cost-effective technique. In this work the selection of industrial waste materials which comes from tile manufacturing such as Tile Waste Powder (TWP) and Foundry Sand (FS) outcome of metal casting industries as an admixture. The Tiles Waste Powder has the nature to improve the compaction behaviour of expansive soil because of its high lime content and Foundry sand are used to develop the strength behaviour of problematic soil due to the presence rich silica content. In this paper, untreated soil got treated using the different proportions such as 5,10, 15,20 and 25% of Tile waste powder and their corresponding the compaction and strength characteristics of the soil sample were determined under different curing periods. Also the tests have been conducted for optimum percentage of tile waste mixed along with varying percentage of Foundry Sand (4, 6, 8, 10 and 12%) in soil sample. The results was obtained from the standard proctor test, UCC and CBR test and it further analysis shows that the increasing the proportion of TWP rises the peak strength of the treated soil up to 20% for the maximum 28 days curing. Also, from the result analysis for the combination of FS and TWP by optimum percentage of Tiles Waste Powder (20%) with 12% of Foundry sand shows the increment in the strength characteristics of soil. The TWP and Foundry Sand can be effectively used in stabilization works in order to utilise the waste by effective minimization of disposal problems.

This paper deals about the optimization and modelling of Wire cut Electric Discharge Machining factors such as pulse OFF-Time (Toff), gap voltage (Vg) and pulse ON-Time (Ton) during machining nano- silicon carbide (nSiC) and nano-zirconium oxide/zirconia (nZrO2) reinforced in Al6061 aluminium alloy matrix. Nanomaterial is synthesis in the planetary high energy ball milling and the hybrid aluminium metal matrix composite (HAMMC) was fabricated by using the stir casting technique. For performing machinability studies on the cast composite. To design the experiments, Response Surface Methodology (RSM) based central composite design (CCD) with face-centred approach is implemented. To optimize input conditions, kerf width and surface roughness were analysed. To determine the suitability of the developed model, Analysis of Variance (ANOVA) is applied and to model the process factors regression analysis is carried out. It is observed from the results that, kerf width decreases when Toff increases and increases with increase in Ton and Vg. A decreasing trend of surface roughness is observed with increasing trend of Vg and surface roughness increase with increase in Ton increases.

Due to demands of high strength and light-weight materials such as Al 6063 aluminum alloy in industrial and aerospace application, it is necessary to choose machining operations by which the materials should be less affected. The present work shows how effectively the responses (HAZ, MRR and circularity) of fiber laser engraving (which is a non-traditional machining operation) varied with the input process parameters (power, scan speed, frequency and fill spacing). On the basis of Taguchi’s L16 orthogonal matrix and S/N ratio analysis, the optimum input parameter combinations were found out for each response individually. Finally, the improvement S/N ratio for closeness coefficient index (CCi) of the above responses was determined to be 3.83 dB by using TOPSIS.

Nanoparticles has become a major part of scientific interest one of the most recent research and applications are done with TiO2 nanoparticles due to its wide range of application in treatment of water, health sector, energy sector and also for the treatment of environment pollutants such as dyes and also in cosmetics the key features of TiO2 nanoparticles involves high surface area that can be utilized for catalytic reactions low toxicity, chemical and physical stability, cost effectiveness and etc. one of its key feature is that is can also be prepared in a green method by using plant extracts acting as stabilizers. It is found in three phases namely Anatase, Rutile and brookite each with is unique applications according to its properties, the application of TiO2 is mainly based upon the modification of the electron-hole pair recombination and the modification in its wide band gap via using the concept of quantum confinement, the absorption range of pure TiO2 nanoparticles is the ultraviolet region is photo catalytically of very less use, the absorption region of TiO2 be prioritized to visible part of the radiation by means of doping metals, non-metals, and semiconductors with narrow band gap which gives composites of TiO2 this can help in the preparation of photocatalyst for the generation of hydroxyl and superoxide radicals which are strong oxidizing, these radical can also be utilized in the treatment purpose of cancer. TiO2 nanoparticles can be prepared by various methodssuch as hydrothermal, sol–gel etc depending upon their application. Also has various shapes like Quantum dots, nanotubes and etc. Classification can also be done on the basis of their photocatalytic products.

Explosive cladding is known for its ability to join a wide variety of metals that other welding methods cannot do. In this present work, the weldability of aluminium alloy and mild steel plates and their bonding strength through an explosive cladding process investigation is performed. Experiments are conducted in the open air using Gelatin (SG-90) variety explosive having a detonation velocity of 3400 m/sec. Experimental trials for single replications were adopted. Ram tensile test has been carried out to determine the bonding strength. The effects of angle of inclination, loading ratio and stand-off distance on the weld strength were analyzed. The possibility of obtaining a sound weld depends on the limiting conditions of the above parameters. The microstructure of the explosive clad joints is studied for varying process parameters which shows a wavy profile that produces higher strength. The strength of the weld in both tensile and shear strength obtained is good and is within the acceptable range. An increase in strength of welded joints is obtained for higher parameter range.

Agricultural and industrial wastes are produced in huge amount throughout the worldwide. In Sultanate Oman and other regions, these wastes are generally not exploited to be re-used or recycled. Waste materials have become of interest due to the beneficial use of the residual biomass left behind. These wastes tend to have harmful impacts on the environment because they might contain strong fibers that decompose at slow rate under normal environmental conditions. Agricultural waste materials contain cellulose which can be extracted to be used in many important processes including the production of bio-plastic and the production of food. The project conducted to isolate and characterize cellulose from waste residuals. Cellulose has been isolated from waste residuals via alkali pretreatment using NaOH followed by bleaching process, while cellulose was produced via acid hydrolysis method using sulfuric acid (H2SO4). The cellulose produced was characterized with Fourier Transform Inferred Spectroscopy (FTIR) in which it is found the main dominant functional groups are O–H and C–H, Scanning Electron Microscope (SEM) which showed a smooth surface morphology which indicates the removal of wax, lignin & hemicellulose and Energy-dispersive X-ray Spectroscopy (EDX) showed that the cellulose approximately contains of 64.5 wt% of C, 30 wt% of O, 1% S and 1.7% Na.

The study is aimed to utilize the silica fume coated plastic waste in the concrete in place of uncoated plastic waste. The main aim of the study is to evaluate the effect on fresh and mechanical properties of concrete after coating the plastic waste with mineral admixture i.e silica fume. The study of utilization of different kinds of plastics forms in concrete has been carried out earlier as well. The major concern is the bonding between concrete mix and the plastic by which the strength could not be attained as desired as per the grade. The present investigation is an endeavor to enhance the bonding characteristics of waste PET fibers with concrete mix by coating them with mineral admixture such as silica fumes by utilizing epoxy resins as an adhesive. The examination was done by utilizing waste PET fibers in aspect ratio AR 25 (50 mm נ2 mm), AR 50 (100 mm נ2 mm) and AR 75(150 mm/2 mm) and consolidate them as bond weight in separate interims of 3%, 6%, 9% and 12%. The modern and mechanical qualities of concrete mix investigated with incorporation of silica fume coated waste PET fibers and ordinary waste PET fibers were contemplated.

The aim of this study is to provide a review on silanized composite performance when exposed in a complex wet aqueous environment and the role of titanium coupling agent as a more stable and reinforcement material in the construction of dental composites. Silanes are considered as the most dominant materials used for surface modification of the filler added to the polymer material in dental applications. Due to the presence of silica in the silane structure, so, the silane coupling agent were considered to be more effective in modifying materials which are consisting of silica because of the similarity in their ordered structure. Silanes are relatively characterized by dehydration inside the oral aqueous environment. On the other hand, titanate coupling agents are effective in serving at a wet environment, because its ability to react with the positive proton available on the surface of the filler (H+). TCAs are superior in performance in comparison to silane by creating a strong internal bonding between the filler and polymer matrix, and having a significant effect on the dispersion and resolving of particles agglomeration and good hydrolytic stability inside the mouth. This paper presents a comparative study between the effects of silane coupling agents against the TCAs performance in oral environment.

Nanoindentation derived mechanical properties and strain rate sensitivity assessment of a set of stir cast metallic reinforced Aluminium-based composites, with an antecedence of anomalous stress oscillations and strain rate insensitivity during hot compression, was investigated in this study. For the evaluation, Al6063 based composites reinforced with 6 wt% CuZnAl, steel, nickel, and SiC particles were subjected to nanoindentation, and their strain rate sensitivity was assessed using strain rate jump test. The results show that the AMCs reinforced with the metallic particles, presented better mechanical properties than those reinforced with SiC. The CuZnAl reinforced AMC had the best hardness (1.25 ± 0.25 GPa) and elastic modulus (∼83GPa), which is opined to be on account of thermoelastic contributions to the basic strengthening mechanisms. The large scatter observed in the mechanical response of the AMCs is largely due to the inhomogeneous particle distribution. The higher indentation resistance with an increase in strain rate, coupled with the absence of displacement bursts, indicated that the composites largely exhibit positive strain rate sensitivity.