Instant Cyclohexene Epoxidation Over Ni-TUD-1 Under Ambient Conditions

Catalysis Letters - To avoid the aggregation problem and activity loss of nickel oxide (NiO) nanoparticles (NPs) in organic reactions, NiO NPs were incorporated into TUD-1 mesoporous material....     

Tribological behavior of composites fabricated by reactive SPS sintering in Ti-Si-C system

In this study, wear and friction behavior of two based-composites from the Ti-Si-C system, (40 wt% TiC; 28 wt% Ti₅Si₃; 17 wt% Ti₃SiC₂) and (18 wt% TiC; 26 wt% Ti₅Si₃; 41 wt% Ti₃SiC₂) reinforced by 15 wt% of large size SiC (100-150 µm) particles were investigated. The four-phase composites exhibited approximatively the same friction coefficient (µ ~ 0.9) under high loads (10 N and 7 N). The composite with high Ti₃SiC₂ showed higher wear rate values by one order of magnitude. However, under 1 N, the composite with high TiC content showed a higher running-in period and a lower steady state µ value (0.37 after 1000 m sliding distance). Scanning electron microscopy, Energy Dispersive X-Ray and Raman spectroscopy analysis of the worn surfaces of the two composites revealed that oxidation was the dominant wear mechanism. The oxidation process and the removal kinetics of the oxides during sliding controlled the tribological behavior of the composites. The influence of processing variables on microstructures development and wear mechanisms of the composites is discussed.     

Simulation of driver fatigue monitoring via blink rate detection,using 65 nm CMOS technology

This paper proposes a system to detect and measure blink rate to determine fatigue levels. The method involved analysing specific frames to determine that a blink occurred, and then monitoring the time between successive blinks. The program was simulated in python using a Raspberry Pi Zero and a standard USB camera. For the blink rate detection block, a gate level schematic was implemented in Cadence software using 65 nm CMOS technology. The design was based around an asynchronous 6-bit based edge counter which was designed using D-flip-flops. The simulation calculated the average blink rate and compared this to the most recent blink rate. The outcome would determine if an alarm signal should be sent to the alarm. The system consumed 130 μA from a 1.2 V power supply.     

Copy-move forgery detection of duplicated objects using accurate PCET moments and morphological operators

This paper presents a new method for copy-move forgery detection of duplicated objects. A bounding rectangle is drawn around the detected object to form a sub-image. Morphological operator is used to remove the unnecessary small objects. Highly accurate polar complex exponential transform moments are used as features for the detected objects. Euclidian distance and correlation coefficient between the feature vectors are calculated and used for searching the similar objects. A set of 20 forged images with duplicated objects is carefully selected from previously published works. Additional 80 non-forged images are edited by the authors and forged by duplicating different kinds of objects. Numerical simulation is performed where the results show that the proposed method successfully detect different kinds of duplicated objects. The proposed method is much faster than the previously existing methods. Also, it exhibits high robustness to various attacks such as additive white Gaussian noise, JPEG compression, rotation, and scaling.     

Synthesis of Novel Tetra(µ3-Methoxo) Bridged with [Cu(II)-O-Cd(II)] Double-Open-Cubane Cluster: XRD/HSA-Interactions,Spectral and Oxidizing Properties

A new double-open-cubane core Cd(II)-O-Cu(II) bimetallic ligand mixed cluster of type [Cl₂Cu₄Cd₂(NNO)₆(NN)₂(NO₃)₂].CH₃CN was made available in EtOH/CH₃CN solution. The 1-hydroxymethyl-3,5-dimethylpyrazole (NNOH) and 3,5-dimethylpyrazole (NNH) act as N,O-polydentate anion ligands in coordinating the Cu(II) and Cd(II) centers. The structure of the cluster in the solid state was proved by XRD study and confirmed in the liquid state by UV-vis analysis. The XRD result supported the construction of two octahedral and one square pyramid geometries types around the four Cu(II) centers and only octahedral geometry around Cd(II) two centers. Interestingly, NNOH ligand acts as a tetra-µ³-oxo and tri-µ²-oxo ligand; meanwhile, the N-N in NNH acts as classical bidentate anion/neutral ligands. The interactions in the lattice were detected experimentally by the XRD-packing result and computed via Hirschfeld surface analysis (HSA). The UV-vis., FT-IR and Energy Dispersive X-ray (EDX), supported the desired double-open cubane cluster composition. The oxidation potential of the desired cluster was evaluated using a 3,5-DTB-catechol 3,5-DTB-quinone as a catecholase model reaction.     

Amination of biochar surface from watermelon peel for toxic chromium removal enhancement

Watermelon peel residues were used to produce a new biochar by dehydration method. The new biochar has undergone two methods of chemical modification and the effect of this chemical modification on its ability to adsorb Cr(VI) ions from aqueous solution has been investigated. Three biochars, Melon-B, Melon-BO-NH_2 and Melon-BO-TETA, were made from watermelon peel via dehydration with 50% sulfuric acid to give Melon-B followed by oxidation with ozone and amination using ammonium hydroxide to give Melon-BO-NH_2 or Triethylenetetramine(TETA) to give Melon-BO-TETA. The prepared biochars were characterized by BET, BJH,SEM, FT-IR, TGA, DSC and EDAX analyses. The highest removal percentage of Cr(VI) ions was 69% for Melon-B,98% for Melon-BO-NH_2 and 99% for Melon-BO-TETA biochars of 100 mg·L~(-1) Cr(VI) ions initial concentration and 1.0 g·L~(-1) adsorbents dose. The unmodified biochar(Melon-B) and modified biochars(Melon-BO-NH_2 and Melon-BO-TETA) had maximum adsorption capacities(Qm) of 72.46, 123.46, and 333.33 mg·g~(-1), respectively.The amination of biochar reduced the pore size of modified biochar, whereas the surface area was enhanced.The obtained data of isotherm models were tested using different error function equations. The Freundlich,Tempkin and Langmuir isotherm models were best fitted to the experimental data of Melon-B, Melon-BO-NH_2 and Melon-BO-TETA, respectively. The adsorption rate was primarily controlled by pseudo-second–order rate model. Conclusively, the functional groups interactions are important for adsorption mechanisms and expected to control the adsorption process. The adsorption for the Melon-B, Melon-BO-NH_2 and Melon-BO-TETA could be explained for acid–base interaction and hydrogen bonding interaction.     

Numerical modeling assessment of mechanical effect in bovine leather drying process

Leather manufacturing involves a crucial energy-intensive drying stage in the finishing process to remove its residual moisture and generates important heat gradients. The numerical model presented in this study has been developed to describe the drying process of porous medium: bovine leather that undergoes deformation due to shrinkage. The mathematical formulation of fundamental heat, mass and momentum transfers’ phenomena during drying summarizes a two-dimensional model considering elastic behavior of bovine leather. The evolution of moisture content, temperature, and mechanical stresses during drying was discussed. The model was validated with experimental results. Numerical simulations show good agreement with experimental results. The study shows that the elastic model keeps the stress sign at the final stage of drying. The deformations induce tensional stresses near the surface equilibrated by compressive stresses within the product. They reached their maximum for normal stresses equal to 5.97 and 3.52?MPa at around 2145 and 868?s, respectively, for normal stresses along x and y directions and then decrease.     

Low temperature ionothermal synthesis of TiO2 nanomaterials for efficient photocatalytic H2 production,dye degradation and photoluminescence studies

The photocatalytic hydrogen generation is a novel, eco-friendly and favourable method for production of green and clean energy using light energy. In this direction, we report low-temperature ionothermal method for the preparation of TiO₂ nanoparticles (NPs) using methoxy ethyl methyl imidazolium tris (pentafluoroethyl) trifluoro phosphate (MOEMINtf₂) as an ionic liquid (IL) at 120°C for 1 day. The synthesized nanomaterials were examined using different spectrochemical methods like UV-DRS, XRD, FT-IR, TEM, BET and TGA-DTA techniques. The mixed phase TiO₂ is obtained with 81.7% of anatase and 18.3% of rutile phase by the XRD studies, and average crystallite size is found to be ∼7 nm. The stretching of Ti-O bond (∼555 cm⁻¹) and few other bands related to ionic liquid were confirmed by FTIR spectrum. The band gap energy was observed to be ∼3.38 eV by UV-DRS analysis. TEM images reveal spherical shape with an average particles size of about 10 nm. Photocatalytic H₂ generation was carried out using TiO₂ NPs and observed the generation of 553 μmol h⁻¹ g⁻¹ via water splitting reaction. Furthermore, the prepared TiO₂ NPs employed for the photocatalytic degradation of methylene blue dye (84.54%), and photoluminescence studies confirms the obtained material can be used in optoelectronic applications with green emission.     

Just-in-time learning for the prediction of oil sands ore characteristics using GPS data in mining applications

For the mining based oilsands industry, it is desirable to determine the quality of the ore delivered to the extraction processes in real-time to make optimal operational decisions such as optimal ore blending to achieve maximal bitumen recovery. Currently, the industry determines the real-time ore characteristics for any given shovel Global Positioning System (GPS) location by first determining the shovel elevation from the topological mine map and then using the determined geological coordinates in the 3D geological block model. It should be noted that the block model is built based on the widely spaced core hole samples, and it is updated only on a yearly basis due to high cost of narrower core hole sampling. Thus, the block model predictions are often inaccurate in between the core hole spacing. On the other hand, mining operations data are available that contain accurate ore characteristics information in the already mined area. Therefore, in this work, we present a just-in-time based data-driven modelling strategy that utilizes the recently available mining operations data to obtain reliable ore characteristics given the GPS data. The prediction capability of ore characteristics using the proposed modelling strategy is validated at core hole locations. Further, the prediction of ore characteristics at non-core hole points demonstrate promising results.