Sulfonated Beet Pulp as Solid Catalyst in One-Step Esterification of Industrial Palm Fatty Acid Distillate

In this research a new heterogeneous catalyst has been prepared for biodiesel production. The catalyst was prepared by sulfonating industrial sugar waste. Unlike homogeneous catalysts, which require further purification and separation from the biodiesel production reaction media, this inexpensive synthetic catalyst does not need to go through an additional separation process. This advantage consequently minimizes the total application costs. The catalyst was prepared by partially carbonizing sugar beet pulp at 400 °C. The carbonization product was then sulfonated with concentrated H₂SO₄ vapor in order to produce a solid catalyst. The prepared catalyst was used in the esterification reaction between palm fatty acid distillate (PFAD) and methanol. The effects of the temperature, methanol/PFAD ratio, reaction time and catalyst dosage on the efficiency of the production were individually investigated. The optimum biodiesel production occurred at 85 °C, a reaction time of 300 min, catalyst dosage of 3 g and methanol/PFAD ratio of 5:1 (mol/mol), lowering the acid value from 198 to 13.1 (mg KOH/g oil) or the equivalent, with a fatty acid methyl ester yield of around 92 %. The results suggest that the synthesized inexpensive catalyst is useful for biodiesel production from PFAD.     

The Influence of Electrophoretic Potential on Ni—Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Nano-Composite Coating

In this study, the effect of electrophoretic voltage changes on Ni—Al₂O₃ nano-composite coating via two step process electrophoretic, and electrochemically on 1100 Al substrate on morphology, corrosion and wear behaviour were studied. In the first step of deposition for determining the optimum amount of Teri Ethanol Amin activator in electrophoretic suspension Transmission Electron Microscopy (TEM) was used. The amount of alumina particles, Nickel ions in the coating and morphology were studied by Energy-dispersive X-ray spectroscopy (EDX) and Field-Emission Electron Microscopy (FESEM). Nanoparticles distribute more homogenous in deposit within using 40 V voltage. Corrosion behaviour of coating was investigated by polarization technique in 3.5 wt % NaCl which shows a decrease in corrosion current from 13.7 μA/cm² to 1.46 μA/cm² versus bare sample.     

Current technologies in the extraction,enrichment and analytical detection of tocopherols and tocotrienols: A review

During the past few years the scientific and medical community has been confronted with a continual interest in vitamin E with the interest prompted by new discoveries. Tocopherols and tocotrienols, commonly known as vitamin E, are extremely invaluable compounds and have various nutritional functionalities and benefits to human health. Great deals of research projects have been launched in order to develop effective methods for the extraction of vitamin E. By and large, three distinct extractive methods are usually employed: supercritical fluid extraction (SFE), molecular distillation, and adsorption methods. These methods are sensitive to different experimental conditions, such as pressure, temperature, and flow rate with noticeable effects on the efficiency of the extraction and enrichment of vitamin E. This review has covered the most commonly adapted extraction methods and has probed into the extraction yields under variable operational parameters.     

Synthesis and characterization of nanocrystalline zirconia powder by simple sol–gel method with glucose and fructose as organic additives

The present study has devised the sol–gel method using glucose and fructose as two organic additives so as to synthesize zirconia nanoparticles. The presence of these organic additives has produced some positive effect on the phase transition from tetragonal to monoclinic and played an important role in the morphology and crystallite size of the nanoparticles. Fourier transform infrared (FT-IR) spectra have shown Zr–O–Zr bond. Crystal phase and crystallite size have been determined by X-ray Diffraction (XRD) analysis. Besides, the morphology of the samples has been investigated by field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM). The optical properties of the samples have been analyzed using photoluminescence (PL) spectroscopy, too. All the analyses consistently have shown fairly uniform nanoparticles with small size, containing both tetragonal and monoclinic phases with crystallite size between 10 and 30 nm.     

Synthesis and characterization of superfine pure tetragonal nanocrystalline sulfated zirconia powder by a non-alkoxide sol–gel route

Nanocrystalline sulfated zirconia powder was prepared by a non-alkoxide sol–gel route using acidic condition (pH 1–2). The samples had superfine crystallites and pure tetragonal phase at 700 °C. Zr(acac)₄ was used as zirconium precursor due to a better retention of sulfate species and H₂SO₄ 0.5 M was used as sulfating agent. Fourier transform infrared (FT-IR) spectra have shown Zr–O–Zr and sulfate bonds. Crystal phase and crystallite size have been determined by X-ray Diffraction (XRD) analysis. Besides, the morphology of the samples has been investigated by field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM). The optical properties of the samples have been analyzed using photoluminescence (PL) spectroscopy, too. All the analyses consistently have shown fairly uniform nanoparticles (calcined at 600 and 700 °C) with very small size and pure tetragonal phase with crystallite size between 5 and 10 nm.     

Immobilization of glucose oxidase on 3D graphene thin film: Novel glucose bioanalytical sensing platform

Electrochemical biosensors are responsible for quantification of analytes for medical diagnostics applications. They are considered as a promising means to investigate the content of a biological sample owing to the direct exchange of a biological process to an electronic output signal. Novel characteristics of nanocarbon materials attracted much attention for fabrication of numerous electrochemical biosensors with developed analytical capacities. This paper aims to provide perceptions of 3D graphene-based electrochemical biosensors and to demonstrate its application in glucose detection. The developed glucose biosensing platform exhibits excellent catalytic activity towards glucose detection over a wide linear range of up to 6 mM with sensitivity of 1.63 μA mM^?1 cm^?2 and the stability of electrode is around 76.9% after one month. The facile and easy electrochemical approach used for the preparation of 3DG–GOD modified GCE may open up new horizons in the production of cost-effective biosensors.     

DiBa: a data-driven Bayesian algorithm for sleep spindle detection

Although the spontaneous brain rhythms of sleep have commanded much recent interest, their detection and analysis remains suboptimal. In this paper, we develop a data-driven Bayesian algorithm for sleep spindle detection on the electroencephalography (EEG). The algorithm exploits the Karhunen-Loève transform and Bayesian hypothesis testing to produce the instantaneous probability of a spindle's presence with maximal resolution. In addition to possessing flexibility, transparency, and scalability, this algorithm could perform at levels superior to standard methods for EEG event detection.     

Learning Physically Based Humanoid Climbing Movements

We propose a novel learning‐based solution for motion planning of physically‐based humanoid climbing that allows for fast and robust planning of complex climbing strategies and movements, including extreme movements such as jumping. Similar to recent previous work, we combine a high‐level graph‐based path planner with low‐level sampling‐based optimization of climbing moves. We contribute through showing that neural network models of move success probability, effortfulness, and control policy can make both the high‐level and low‐level components more efficient and robust. The models can be trained through random simulation practice without any data. The models also eliminate the need for laboriously hand‐tuned heuristics for graph search. As a result, we are able to efficiently synthesize climbing sequences involving dynamic leaps and one‐hand swings, i.e. there are no limits to the movement complexity or the number of limbs allowed to move simultaneously. Our supplemental video also provides some comparisons between our AI climber and a real human climber.     

Comparative electrochemical study of self-assembled monolayers of 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, and 2-mercaptobenzimidazole formed on polycrystalline gold electrode

Comparative electrochemical behavior of self-assembled monolayers (SAMs) of three heteroaromatic thiols, 2-mercaptobenzoxazole (MBO), 2-mercaptobenzothiazole (MBT), and 2-mercaptobenzimidazole (MBI) are investigated by means of cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The electrochemical characteristics of the electrode/solution interface are considerably and differently affected by thiols constructing the SAMs. The consumed charges for reductive desorption of SAMs, which is criterion for the amount of chemically adsorbed thiol, are significantly different for these three SAMs, specially for MBT, implying that SAM of MBT is formed through both sulfur atoms; the thiol sulfur and skeleton sulfur of the thiazole ring. Desorption potentials of the SAMs have shown the following order for strength of gold-sulfur bond: MBT > MBO > MBI. Activity of the three SAMs as pH-sensitive interfaces was also investigated and their surface-pK_a values derived from the EIS measurements showed this order for acidic strength of SAMs: MBO > MBT > MBI. This is the same order expected due to the difference in electronegativity of the O, S, and N heteroatoms, and confirms that the most electron-rich ring imidazole is attached to the benzene ring of MBI. A comparison of the interfacial charge transfer resistance variation as a function of gold immersion time in thiols solution reveals that kinetics of Au-MBT assembly is different from those of two others and confirms formation of Au-MBT SAM via both sulfur atoms of MBT.