Miracle-dz/UniFAR-FTUs huggingface dataset:
1,4‐Diaza‐bicyclo[2,2,2]octane as a Novel and Efficient Catalyst for the Synthesis of 3,4,6‐Trisubstituted 2‐Pyridone Derivatives

3,4,6-Trisubstituted 2-pyridone derivatives have been synthesized in good to excellent yields through a condensation reaction of various 1,3-diketones with amides in the presence of 1,4-Diaza-bicyclo[2,2,2]octane (DABCO) at reflux temperature.
A Monitoring Tape for Chlorine Gas with N, N-Diethyl-p-Phenylenediamine Sulfate

A porous cellulose tape impregnated with a processing solution that includes N, N-Diethyl-p-phenylenediamine (DPD) sulfate, glycerin and methanol was developed for the detection of chlorine gas in air. When the sample is passed through the tape, chlorine reacts with DPD to form a red stain. The intensity of the red stain is proportional to the concentration of chlorine at a constant sampling time and flow rate, and was recorded by measuring the intensity of reflected light (555 nm) . The detection limit was 0.03 ppm of chlorine with a sampling time of 60 s and a flow rate of 200 ml min-1. The sensitivity of the tape could be maintained for at least 1 month when stored in dark clean box.Reproducibility tests showed that the relative standard deviations of the response (n=10) was 2.5 % for 0.1ppm of chlorine gas. No interference was observed from ethanol (1 vol.%), acetone (1 vol.%), trichloroethylene (1 vol.%), carbon monoxide (100 ppm), hydrogen sulfide (30 ppm), sulfur dioxide (51 ppm) or ozone (2 ppm) . The relative intensities of nitrogen dioxide and fluorine gas were 25 and 13 % of that of chlorine, respectively.
The coupling between foam viscoelasticity and interfacial rheology

We study the impact of interfacial rheology on the linear viscoelastic relaxations of disordered 3D foams. Their complex shear modulus G* = G′ + iG′′ is measured as a function of frequency, bubble size, liquid viscosity and surface dilatational modulus. We show that for foams with very rigid interfaces the variations of G* with frequency f between 1 and 100 Hz deviate from the behavior previously predicted as a generic consequence of topological disorder and observed for foams with mobile or moderately rigid interfaces. Our experiments demonstrate that the relaxations slow down as the bubble size or the foaming liquid viscosity increases. We show under which conditions, depending on the interfacial rigidity, the loss factor G′′/G′ can be collapsed on master curves by applying a scale factor to the frequency. The dependence of this scale factor on the bubble size and viscosity constitutes a robust criterion helping to identify the dominant dissipation mechanism.
Structural and optical properties of self‐assembled InGaAs quantum dots

A one step method for the production of quantum dots is presented. The method exploits the mismatch strain of molecular beam epitaxy (MBE) deposited InGaAs on GaAs to induce a transition from the two‐dimensional growth mode to the three‐dimensional (Stranski–Krastanow) growth mode. The cluster size is limited to quantum dimensions by precisely controlling the amount of InGaAs that is deposited in order to cause the growth mode transition. Very narrow lateral size distributions with standard deviations of 14% on the dot area have been obtained. Smooth MBE growth of GaAs over these clusters produces a layer of quantum dots, whose high quality and uniformity has been observed with transmission electron microscopy, atomic force microscopy, and photoluminescence (PL). The quantum dot PL intensity is enhanced compared to a reference quantum well. Resonances in photoluminescence excitation (PLE) spectra suggest that the density of states in these dots has minima close to zero between the quantum states, as expec.
A Short Review of High-Temperature Wetting and Complexion Transitions with a Critical Assessment of Their Influence on Liquid Metal Embrittlement and Corrosion

The basic concepts and new developments in the general areas of grain boundary segregation (adsorption), wetting, and complexion (interfacial phase-like) transitions are briefly reviewed. Subsequently, recent studies in several relevant areas are discussed. At the atomic level, the formation of bilayers in Ni-Bi and Cu-Bi have been observed and found to be the root cause for liquid metal embrittlement (LME). At the microstructural level, the presence of minor impurities or co-alloying elements can significantly enhance the intergranular penetration and liquid metal corrosion (LMC). Furthermore, triple-grain-line wetting by a liquid metal can occur at high temperatures, which may significantly affect corrosion resistance (for LMC), as well as LME. Somewhat surprisingly, Bi vapors can penetrate along the triple-grain lines in S-doped Ni specimens to form open channels, which can be considered as an unusual case of triple-line wetting by a vapor phase. A coherent theme of this review and critical assessment .
Analysis of the hysteretic behavior of silicon nanowire transistors

We e present a combined experimental and theoretical analysis of the transport properties of silicon nanowire (NW) transistors. The NWs are grown by catalytic chemical vapour deposition and are later deposited on pre-patterned oxidized silicon substrates that provide the device source and drain electrodes. A back gate configuration is used for our study. Through a controlled nickel diffusion, parts of the nominally undoped NWs are turned into nickel silicide NWs. thus providing a direct metallic nanolead to the semiconducting wire. The transistors obtained with NWs of 10-30 nm diameters display p-type behaviour, current densities up to 0.8 MA/cm2 and on/off current ratios of up to 107. The subthreshold characteristics show a strong hysteresis. The simulation based on a drift-diffusion approach indicates that traps at the interface between the NWs and SiO2 are responsible for such behaviour. (8 References).
Tunable Optical and Structural Properties of MgxZn1-xO Films Prepared by in-situ Atomic Layer Doping Technique

Magnesium zinc oxide (MgxZn1−xO) thin films with tunable optical and structural properties have been prepared by in-situ atomic layer doping technique. The linear dependence of the Mg content on the Mg atomic layer doping percentage indicates this in-situ atomic layer doping is a precisely controlled technique for the Mg incorporation into ZnO. X-ray characterization reveals that solubility limit of MgO in the MgxZn1−xO films is approximately x = 0.1. Photoluminescence (PL) measurement shows the nearband-edge emission of MgxZn1−xO films shifts from 378 nm to 346 nm with an increase of the Mg content. The temperature dependent PL spectroscopy shows that the activation energy of thermal quenching process increases from 17 meV in pure ZnO to 48 meV in Mg0.1Zn0. 9O films, indicating that thermal quenching is suppressed by the Mg incorporation. The optically-pumped stimulated emission at λ ∼ 356 nm was observed from the Mg0.1Zn0. 9O film, manifesting the high optical quality of the MgxZn1−xO films grown by the in-situ atomic layer doping technique.
Effect of Processing on Nutrients and Anti-nutrients of Castor Oil Bean (Ricinus communis) Seeds and By-products

2 Abstract: Studies were conducted on the proximate, mineral and anti-nutrients composition of raw and processed castor oil seeds and by-product. Processing methods adopted include fermentation, dry and moist heat (toasting and boiling) treatments respectively. The results revealed that, the processing methods have tremendous effect on the chemical and anti-nutrient components of the seed and by product . Nevertheless, the traditional methods of processing employed eventually reduced the concentration of anti- nutrients and encouraged its utilization in animal nutrition generally.
Implicit solvent models for protein-ligand binding: Insights based on explicit solvent simulations

Solvent effects play a crucial role in mediating the interactions between proteins and their ligands. Implicit solvent models offer some advantages for modeling these interactions but they have not been parametrized on such complex problems, and therefore it is not clear how reliable they are. We have studied the binding of an octapeptide ligand to the murine MHC class I protein using both explicit solvent and implicit solvent models. The solvation free energy calculations are more than 103 faster using the Surface Generalized Born implicit solvent model as compared to FEP simulations with explicit solvent. For some of the electrostatic calculations needed to estimate the binding free energy, there is near quantitative agreement between the explicit and implicit solvent model results; overall the qualitative trends in the binding predicted by the explicit solvent FEP simulations are reproduced by the implicit solvent model. With an appropriate choice of reference system based on the binding of the dischar.
Catalytic Deoxygenation of Carbohydrate Renewable Resources

Cellulose, hemicellulose, and lignin, the components of wood, are quantitatively the most important renewable feedstocks for the upcoming biobased chemical industry. In contrast to the fossil raw materials, these renewables are more or less highly oxidized. Therefore, it is clear that for bulk chemicals that are presently produced petrochemically, alternatives need to be developed that are based on these renewable raw materials. Methods are needed to remove selectively the oxygen atoms of the renewable chemicals such as glucose and lignin, to obtain molecules with less or finally without oxygen. Several strategies are being considered. The first one is to use biomass for the production of biooil by pyrolysis. The biooil together with coke can be converted to synthesis gas (CO + H2), which can in turn be used to synthesize the necessary molecules starting with Fischer–Tropsch synthesis. Importantly, this approach uses the complete carbon and hydrogen content of the biomass. Alternatively, biooil can be converted to base chemicals (ethene, propene, butene, butadiene, benzene, toluene, ethylbenzene, and xylene) by using an integrated catalytic approach that combines hydroprocessing with zeolite catalysis, using essentially the carbohydrate content of biomass. In contrast, when renewables are used as feedstock for organic syntheses, nature’s synthetic input should be used as far as possible to obtain, from the natural pool of abundant carbon compounds in one or only very few chemical reaction steps, those complex molecules which we need. Thus, for example, adipic acid and e-caprolactam are important C6-bulk chemicals. Presently, it is a great challenge to produce them from abundant glucose, the linear C6-chain provided by nature. Only the four hydroxyl groups at C-2 to C-5 should be substituted by hydrogen, whereas C-1 and C-6 should be oxidized to carboxyl to obtain adipic acid. The same applies to the synthesis of ecaprolactam with the exemption of C-6. Here, the hydroxyl group has to be substituted by an amino group. That would be most advantageous compared to the established production based on benzene/cyclohexane. (Scheme 1) With respect to carbohydrates, three main strategies are currently under investigation: 1) the acid-catalyzed dehydration to give furfural from pentoses and hydroxymethylfurfural from hexoses. 2) hydrogenolysis reactions to give sugar alcohols, most importantly sorbitol from glucose, and under C,C-bond scission smaller polyols and finally hydrocarbons, and 3) the deoxydehydration (DODH) reaction, which removes two adjacent hydroxyl groups from vicinal diols to afford alkenes (Scheme 2). The latter reaction type is highlighted here. During the last few years DODH using highvalent oxorhenium complex catalysts have been developed for the deoxygenation of diols and polyols, and most importantly of sugars.
Transmission block interminal nervetwigs: asingle fibre electromyographic

SUMMARY Single fibre electromyography hasbeenperformed inpatients withpartial nerve lesions, amyotrophic lateral sclerosis, progressive spinal muscle atrophy, muscular dystrophy, and distal hereditary myopathy. Therecorded action potentials were often more complex thaninthe normal muscle duetoincreased fibre density inthemotorunitandtheindividual spike components showeda large jitter andoccasional blockings. Sometimes twoor more spikes ina complex disappeared andreappeared simultaneously upon successive discharges. Thisphenomenon, called 'paired blocking', hasbeenfurther investigated. Thejitter oftheblocking potentials inrelation to therestofthecomplex was large, up to500ttsec. Thedegree ofblocking increased withincreasing innervation frequency until iteventually proceeded tototal blockduring continuous activity. Sometimes aslight effect on blocking was seenafter edrophonium. Thistypeofblock isprobably localized intheterminal nervetwigs, perhaps innewlyformedsprouts. Thephenomenon ofneurogenic blocking may contribute tothefatigue clinically experienced indifferent denervation-reinnervation cases.
ANTIOXIDANT POTENTIAL OF METHANOLIC EXTRACT OF MONSTERA ADANSONII

Antioxidants prevent oxidative damage caused by free radical and can be used in cardiovascular and anti-inflammatory diseases. The presence of natural antioxidant in plants is well known. The present study was undertaken to find the antioxidant value of the plant Monstera adansonii . The amount of total phenols, flavonoids, tannins and radical scavenging activity was studied. The analysis carried out was, DPPH free radical scavenging activity, Ferric reducing antioxidant power assay, Superoxide anion scavenging activity and Nitric oxide scavenging activity. Plant extracts were prepared by maceration method using methanol. Results show that Monstera adansonii had highest yield of methanolic extract (3.84%), total phenolic content (10.34mg/g) and antioxidant activity (89.84%) using DPPH method. Increasing the concentration of the extracts resulted in increased ferric reducing antioxidant power for the methanolic extract tested. The plants, Monstera adansonii, may be potent source of natural antioxidants.
Performance and emission characteristics of CI engine, fuelled with diesel and oxygenated fuel blends.

Vegetable oils are a potential alternative towards partial or total substitution of diesel fuels. In this study, we used ethanol as the solvent, and a bio fuel enhancer as additive to explore the possible use of higher percentages of biodiesel in an unmodified diesel engine. Biodiesel was produced from cashew nut shell liquid (CNSL) by pyrolysis process. A mixture containing 80% (by volume) of Number 2 diesel fuel and 20% (by volume) of biodiesel is called here as B20. The effect of 10% ethanol, (by volume) blended with B20 was studied in a single cylinder, four strokes direct injection diesel engine after adding a bio fuel enhancer as additive. The impact of test fuels on engine torque, power, brake specific fuel consumption, brake thermal efficiency, and exhaust gas temperature were investigated by the performance tests. The influence of blends on CO, CO2, HC, NO and smoke opacity were measured by emission tests. The experimental results showed that when a fuel mixture containing 10% ethanol, B20 and a bio fuel enhancer as additive was used, the exhaust emissions were fairly reduced; especially the NO is reduced remarkably by 30% when compared to using B20 alone. Smoke opacity was reduced by 20% when compared to using diesel alone.
Liquid crystal phase diagram of the Gay-Berne fluid

In this paper we report computer simulation results for bulk Gay-Berne fluids with anisotropy parameters κ = 3 and κ′ = 5. Using molecular dynamics simulations in the NVT ensemble, we identify isotropic fluid, nematic and smectic B phases. We observe that the nematic phase is only stable for reduced temperatures T* > 0·80. At lower temperatures, the isotropic phase directly evolves to the smectic B phase via a first order transition. We also give evidence of a weakly first order transition which involves a tilt of the molecular orientations with respect to the smectic planes. The effect of the attractive anisotropic forces in stabilizing the orientationally ordered phases is also studied by performing simulations for a WCA-type Gay-Berne fluid. When combined with previous studies of the vapour-liquid transition by Gibbs ensemble Monte Carlo simulations, and of the isotropic-nematic transition by thermodynamic integration, the results presented here provide quite a complete picture of the phase diagram for.
Infrared spectra of the complexes of malaoxon with some anhydrous metal chlorides

Treatment of malaoxon with the anhydrous chlorides of zinc (II), manganese (II) copper (II) and iron (III) in carbon tetrachloride below 10° yielded solid compounds corresponding to a (1:1) composition. The infrared spectra of these compounds show coordination through the P = O bond.
Experimental study of bimolecular reaction kinetics in porous media.

The representation of multispecies chemical transformations into models for porous media flow and transport is investigated. Since the rate of transformation is dependent on the actual concentrations of the reactants inside the pore-spaces (rather than the averaged concentration that is amenable to a porous continuum model) such models may show a lesser or greater rate of transformation than is actually occurring, depending on the pore-scale correlation of the reactant concentrations. To examine this experimentally, a bimolecular reaction (A + B → Product) in a saturated porous media flow in a column was studied using a spectrophotometer. The second-order rate constant of the reaction was independently determined in well-mixed batch tests. In the reactive transport experiments, the porous medium column was initially saturated with one reactant, the other reactant was injected at one longitudinal end of the column, and the effluent concentrations were measured. It is documented that a reactive transport mo.
Micro-assembly planning with van der Waals force

Investigates a new aspect of fine motion planning for the micro-domain. As parts approach 1-10 /spl mu/m or less in outside dimensions, interactive forces such as van der Waals and electrostatic forces become major factors that greatly change the assembly sequence and path plans. It has been experimentally shown (Miyazaki and Sato, 1996, and Koyano and Sato, 1996) that assembly plans in the micro-domain are not reversible, motions required to pick up a part are not the reverse of motions required to release a part. The paper develops the mathematics required to determine the goal regions for pick up, holding, and release of a micro-sphere being handled by a rectangular tool.
Preparation of Carbon Nanotubes/Neutral Red Composite Film Modified Electrode and Its Catalysis on Rutin

Neutral red was directly electropolymerized onto the carbon nanotubes modified electrode. A polymerized neutral red/carbon nanotubes composite film was characterized by scanning electron micrograph (SEM) and cyclic voltammetry (CV). Well-defined voltammetric responses are observed for [Fe(CN)6]4−/3− on the composite film modified glassy carbon electrode. And it's found that this modified electrode has good catalysis on the redox of rutin. Differential pulse voltammetry method was used to determinate the concentration of rutin and obtain a linear equation between the current and concentration in a certain range. The modified electrode is satisfied with us for its good sensibility and stability.
Surfactants and Bacterial Bioremediation of Polycyclic Aromatic Hydrocarbon Contaminated Soil—Unlocking the Targets

The activities of man produce significant levels of toxic polycyclic aromatic hydrocarbon compounds (PAHs), which have been identified as excellent candidates for biodegradative removal from contaminated sites. PAHs strongly sorb to soil particles and can also partition into a nonaqueous phase, often limiting bioavailability. In this context, synthetic surfactants and biosurfactants will be discussed as a means to mobilize and solubilize PAHs, potentially increasing bioavailability and subsequent microbial degradation. The fundamentals of bioremediation will be discussed as an important tool that can be used to reduce, remove, or attenuate pollutants at PAH-contaminated sites.
Nanoparticles in a Liquid: New State of Liquid?

Nanoparticles in a Liquid: New State of Liquid? Atoms at a solid surface have different co-ordination numbers, bond lengths, and bond angles, with manifest differences in chemical and physical properties of surface atoms relative to their counterparts in the bulk material. In materials where the fraction of atoms at or near the surface is relatively small (e.g. most bulk materials) the effects of surface atoms on macroscopic phenomena are often negligible. This is not true when materials are in the form of nanoparticles, where their highly subdivided state leads to a very high fraction of the total atoms residing at or near a surface. For nanoparticles, the differences between the bulk and surface properties of constituent atoms can often dominate the overall properties of the material. These effects manifest themselves as an increase in vapor pressure, a decrease in melting point, and/or an increase in surface tension/ surface energy when compared to their macroscopic counterparts. Nanoparticles also experience significant changes in optical and electronic properties due to quantum size effects and energetic effects initiated by the increasing contribution of the particle surface to the energy of particles.
Confocal scanning light microscopy with high aperture immersion lenses

The imaging characteristics of a confocal scanning light microscope (CSLM) with high aperture, immersion type, lenses (N.A. = 1·3) are investigated. In the confocal arrangement the images of the illumination and detector pinholes are made to coincide in a common point, through which the object is scanned mechanically. Results show that for point objects the theoretically expected improved response by a factor of 1·4 in comparison with standard microscopy can indeed be realized. Low side lobe intensity and absence of glare permits the imaging at high resolution of weak details close to strong features. A further improvement by a factor of 1·25 in point resolution in CSLM is found after apodization with an annular aperture. Due to the scanning approach all possibilities of electronic image processing become available in light microscopy.
Growth pattern and bonding of copper clusters

Density functional theory calculations of copper cluster Cun with n = 2-10 are analyzed with respect to their molecular orbitals. It is shown that shell type orbitals of s, p ,a ndd character govern the electronic structure growth and have an influence on the geometric structure. They appear as highest occupied molecular orbital, lowest unoccupied molecular orbital, or as orbitals energetically close to these. Their occurrence can explain the magic numbers of shell models. The bonding in such structures can be explained by an analysis of the critical points of the molecular electrostatic potential. Six types of critical points are observed and related to bonds, rings, cages, lone pairs, and their connections. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem 90: 594-602, 2002
Dynamic nuclear polarization: Yesterday, today, and tomorrow

A review is given of the history and basic principles of dynamic nuclear polarization (DNP) in condensed matter, starting from the Overhauser pioneering work and up to the modern applications in chemistry and medicine. Different physical mechanisms of DNP, such as the Overhauser effect, solid effect, electron-nuclear cross relaxation, and thermal mixing are considered. Further prospects of the DNP techniques for future are discussed.
Recent advances in electrochemical glucose biosensors: a review

Glucose detection is of great significance in biomedical applications. Principles, methods and recent developments in electrochemical glucose sensors are reviewed here. Special attention is given to the discussion on some problems and bottlenecks in areas of nonenzymatic and enzymatic (glucose oxidase-based) amperometric glucose sensing.