Miracle-dz/UniFAR-FTUs huggingface dataset:
Novel Pt(II) Mono- and Biscarbene Complexes: Synthesis, Structural Characterization and Application in Hydrosilylation Catalysis

Reactions of imidazolium and benzimidazolium halides with PtBr2 and PtI2 in DMSO afford cis-Pt(II) heterocyclic carbene DMSO mixed ligand complexes 1−3 and biscarbene complexes 4−6. The reaction between 1,3-dibenzylbenzimidazolium bromide and PtBr2 in CH3CN gives no carbene complex but a benzimidazolium hexabromoplatinate(IV) salt 7. All the products have been fully characterized by NMR and ESI-MS spectroscopy as well as X-ray single-crystal diffraction study. Both intramolecular γ-hydride interactions with metal or its coordinated bromide and intermolecular H-bonding between heterocyclic proton with bromide are evident in some of these structures. These complexes are active in the hydrosilylation of terminal alkynes (phenylacetylene and trimethylsilylacetylene) with triethylsilane and bis(trimethylsiloxy)methylsilane. When phenylacetylene is used, the monocarbene complexes (1−3) show higher catalytic activity than chelating biscarbene analogues (5 and 6). Non-chelating biscarbene complex 4 gives a differ.
Charge exchange recombination spectroscopy as a plasma diagnostic tool

Intensity and line profile measurements of the spectra of light hydrogenic ion which are excited by charge exchange reactions with fast neutral atoms are being widely used as diagnostics for fusion plasma research. This technique, which is referred to as charge exchange recombination spectroscopy, allows measurements of the densities of fully stripped impurity ions and particle transport coefficients with only minor uncertainties arising from atomic processes. The excitation of long wavelength transitions in light ions such as He/sup +/, C/sup 5 +/, and O/sup 7 +/ allows relatively easy measurements of ion velocity distributions to determine ion temperatures and plasma rotation velocities. Among its advantages for such measurements are the facts that fiber optic coupling between a remote spectrometer and the immediate reactor environment is possible in many cases. The measurement is localized by the intersection region of a neutral beamline and viewing sightline, and intrinsic ions can be used so that injection of potentially perturbing impurities can be avoided. A particularly challenging application of this technique lies in the diagnosis of alpha particles expected to be produced in the present generation of Q approx. = 1 tokamak experiments.
International Journal of Food Engineering Equilibrium Moisture Content Models for Lafun

Insights into the relationship between the air relative humidity (water activity (aw)) and equilibrium moisture content of food materials is essential to maintain good keeping quality and optimize process operation. The adsorption isotherms for cassava flour (lafun) were investigated with the static gravimetric method. Concentrated acid (H2SO4) solutions were used to vary the micro-climate in the study and presented in an easy-to-use template-like format over the range of temperature (2740oC) and aw (0.10-0.80) usually experienced in the tropical environment. The experimental data were compared with five widely recommended models in the literature for food sorption isotherms (GAB, modified GAB, modified Oswin, modified Henderson & modified Chung-Pfost). The moisture sorption isotherms were sigmoidal in shape and were influenced by temperature. The modified Oswin model was found to be most adequate whilst the modified GAB appears not suitable to model the adsorption isotherms for lafun.
Lead-tellurium oxysalts from Otto Mountain near Baker, California: VI. Telluroperite, Pb3Te4+O4Cl2, the Te analog of perite and nadorite

Abstract Telluroperite, Pb3Te4+O4Cl2, is a new tellurite from Otto Mountain near Baker, California. The new mineral occurs on fracture surfaces and in small vugs in brecciated quartz veins in direct association with acanthite, bromine-rich chlorargyrite, caledonite, cerussite, galena, goethite, and linarite. Various other secondary minerals occur in the veins, including six new tellurates, housleyite, markcooperite, paratimroseite, ottoite, thorneite, and timroseite. Telluroperite is orthorhombic, space group Bmmb, a = 5.5649(6), b = 5.5565(6), c = 12.4750(14) Å, V = 386.37(7) Å3, and Z = 2. The new mineral occurs as rounded square tablets and flakes up to 0.25 mm on edge and 0.02 mm thick. The form {001} is prominent and is probably bounded by {100}, {010}, and {110}. It is bluish-green and transparent, with a pale bluish-green streak and adamantine luster. The mineral is non-fluorescent. Mohs hardness is estimated to be between 2 and 3. The mineral is brittle, with a curved fracture and perfect {001} cleavage. The calculated density based on the empirical formula is 7.323 g/cm3. Telluroperite is biaxial (-), with very small 2V (~10°). The average index of refraction is 2.219 calculated by the Gladstone-Dale relationship. The optical orientation is X = c and the mineral exhibits moderate bluish-green pleochrosim; absorption: X < Y = Z. Electron microprobe analysis provided PbO 72.70, TeO2 19.26, Cl 9.44, O≡Cl -2.31, total 99.27 wt%. The empirical formula (based on O+Cl = 6) is Pb2.79Te4+1.03O3. 72Cl2.28. The six strongest powder X-ray diffraction lines are [dobs in Å (hkl) I]: 3.750 (111) 58, 2.857 (113) 100, 2.781 (020, 200) 43, 2.075 (024, 204) 31, 1.966 (220) 30, and 1.620 (117, 313, 133) 52. The crystal structure (R1 = 0.056) is based on the Sillén X1 structure-type and consists of a three-dimensional structural topology with lead-oxide halide polyhedra linked to tellurium/lead oxide groups. The mineral is named for the relationship to perite and the dominance of Te (with Pb) in the Bi site of perite.
A Small Molecule Non‐fullerene Electron Acceptor for Organic Solar Cells

Organic bulk heterojunction photovoltaic devices predominantly use the fullerene derivatives [C60]PCBM and [C70]PCBM as the electron accepting component. This report presents a new organic electron accepting small molecule 2‐[{7‐(9,9‐di‐n‐propyl‐9H‐fluoren‐2‐yl)benzo[c][1,2,5]thiadiazol‐4‐yl}methylene]malononitrile (K12) for organic solar cell applications. It can be processed by evaporation under vacuum or by solution processing to give amorphous thin films and can be annealed at a modest temperature to give films with much greater order and enhanced charge transport properties. The molecule can efficiently quench the photoluminescence of the donor polymer poly(3‐n‐hexylthiophene‐2,5‐diyl) (P3HT) and time resolved microwave conductivity measurements show that mobile charges are generated indicating that a truly charge separated state is formed. The power conversion efficiencies of the photovoltaic devices are found to depend strongly on the acceptor packing. Optimized K12:P3HT bulk heterojunction devices have efficiencies of 0.73±0.01% under AM1.5G simulated sunlight. The efficiencies of the devices are limited by the level of crystallinity and nanoscale morphology that was achievable in the blend with P3HT.
Switching phenomena in chromium-doped vanadium sesquioxide

(V1−xCrx)2O3 with x=0.012 exhibits both S- and Z-type switching characteristics in studies of current–voltage curves at temperatures 170–230 K. The effects are linked to electrothermal instabilities and to filamentary conduction. The samples are stable under voltage cycling in appropriate temperature ranges.
Changes of hen eggs and their components caused by non-thermal pasteurizing treatments II. Some non-microbiological effects of gamma irradiation or hydrostatic pressure processing on liquid egg white and egg yolk

Experiments were performed to study changes caused by irradiation or high hydrostatic pressure pasteurization of liquid egg white by differential scanning calorimetry, spectrofluorimetry, electronic nose measurements and NIR-spectrometry. The non-thermal pasteurization treatments were also assessed in relation to loss of carotenoid content, and lipid- and cholesterol oxidation of liquid egg yolk. Unlike radiation pasteurization, high pressure processing caused protein denaturation in egg white, which manifested in changes of its DSC-thermogram and intrinsic tryptophan fluorescence. Electronic nose testing showed changes of the head-space volatile composition of egg albumen, particularly as a function of radiation treatment. Both treatments caused changes in the NIR-spectrometric “fingerprint” of the liquid egg white. Various chemometric analyses of the results of the latter instrumental methods, particularly statistical techniques developed by the group of one of the co-authors of this article, demonstrat.
Electron microscopy analysis of decagonal quasicrystals in the Al–Cu–Co–Si system

Abstract Large needle-shaped grains of a decagonal quasicrystal in the Al–Cu–Co–Si quaternary system were prepared by slow cooling from the melt. Scanning electron microscopy, X-ray diffraction and convergent-beam electron diffraction patterns confirmed that the needles have a decagonal quasicrystal structure. Thin slices normal to the tenfold directions were prepared for transmission electron microscopy. Diffuse streaks along symmetric directions around the fundamental spots and in between weaker diffraction spots as well as satellite spots were observed in the tenfold diffraction patterns. Bright-field and dark-field images showed discontinuous lines or striations lying perpendicular to the direction of diffuse streaking. Dark contrast at the point of discontinuity of the fringes are observed along a particular direction. High-resolution electron microscopy images also indicated features corresponding to the striation contrast. The striation contrast is shown to be associated with a phason disorder boundary in the partially ordered decagonal phase. Satellite spots are attributed as a characteristic feature of the partially ordered decagonal superlattice structure, which is an intermediate state between a fully disordered and fully ordered structure of the decagonal phase. The atomic rearrangement or phason displacements in certain symmetric directions (along the pentagrids or Ammann lines in the structure) give rise to the striation contrast observed in the images. The evolution of domains consisting of periodic and quasiperiodic parallel boundaries in localized regions can be interpreted as one of the signatures of an intermediate structural state prior to the formation of a fully ordered decagonal lattice.
SELECTIVE CHROMATOGRAPHIC METHODS FOR THE DETERMINATION OF ROSUVASTATIN CALCIUM IN THE PRESENCE OF ITS ACID DEGRADATION PRODUCTS

Two accurate and sensitive stability-indicating methods for the determination of rosuvastatin calcium in the presence of its acid degradation products are presented. The first method utilizes quantitative spectrodensitometric evaluation thin-layer chromatography (TLC) of rosuvastatin calcium in the presence of its acid degradation products, using ethyl acetate/methanol/ammonia (7:3:0.01, by volume) as a mobile phase. Chromatograms are scanned at 245 nm. This method analyzes rosuvastatin calcium in a concentration range of 0.6–3.4 µg/band with mean percentage recovery of 99.78 ± 1.42. The second method is a high-performance liquid chromatography (HPLC) method for the simultaneous determination of rosuvastatin calcium in the presence of its acid degradation products. The mobile phase consists of water/acetonitrile/methanol (40:40:20, by volume). The standard curve of rosuvastatin calcium shows a good linearity over a concentration range of 10–60 µg mL−1 with mean percentage recovery of 100.22 ± 0.86. These methods were successfully applied to the determination of rosuvastatin calcium in bulk powder, laboratory-prepared mixtures containing different percentages of the acid degradation products, and pharmaceutical dosage forms. The validity of results was assessed by applying standard addition technique. The results obtained were found to agree statistically with those obtained by a reported method, showing no significant difference with respect to accuracy and precision.
Perturbative treatment of triple excitations in coupled‐cluster calculations of nuclear magnetic shielding constants

A theory for the calculation of nuclear magnetic shielding constants at the coupled‐cluster singles and doubles level augmented by a perturbative correction for connected triple excitations (CCSD(T)) has been developed and implemented. The approach, which is based on the gauge‐including atomic orbital (GIAO) ansatz, is illustrated by several numerical examples. These include a comparison of CCSD(T) and other highly correlated methods with full configuration interaction for the BH molecule, and a systematic comparison with experiment for HF, H2O,NH3, CH4, N2, CO, HCN, and F2. The results demonstrate the importance of triple excitations in establishing quantitative accuracy. Finally, the ability of GIAO‐CCSD(T) to make accurate predictions for difficult cases is explored in calculations for formaldehyde (CH2O), diazomethane(CH2NN), and ozone (O3).
Effect of cultivation on physical and chemical properties of a Vertisol in middle Awash Valley, Ethiopia

Abstract An investigation was conducted to study physical and chemical change at two adjacent soil sites, one used for irrigated cotton since 1972 (cultivated) and the other for traditional grazing and browsing (uncultivated). The soil at each site, a clayey Vertisol was described and sampled for physical and chemical analyses. The result showed that the surface layer of the uncultivated soil was denser and more compact than that of the cultivated soil. Soil porosity and moisture build‐up were lower in the uncultivated than in the cultivated soil. Due to percolation of irrigation water and leaching of soluble salts, salinity, concentration of soluble cations, anions, and exchangeable cations were slightly higher at the lower soil depths in the cultivated than in the uncultivated soil. The exchangeable sodium percentage (ESP) also followed the same trend. Correlation coefficient between the values of electrical conductivity, soluble and exchangeable cations, sodium adsorption ratio (SAR), and ESP were more.
Correlation between X-ray chemical shift and partial charge in Tc(IV) complexes: Determination of Tc partial charge in TcnOy(4n-2y)+

The chemical shift of the X-ray absorption K-edge of Tc(IV) complexes determined by X-ray Absorption Spectroscopy (XAS) measurement was studied. A correlation between edge position (ΔE) and partial charge on Tc atoms (δTc) was determined. This correlation was used to determinate δTc in TcnOy(4n-2y)+. Furthermore, a theoretical relation between δTc and the charge of TcnOy(4n-2y)+, was also established and the overall charge of this complex was estimated.
Light induced molecular release from vesicles based on amphiphilic linear-dendritic block copolymers

We report on the synthesis and characterization of new amphiphilic linear-dendritic block copolymers (LDBCs) as well as their self-assembly in water to form polymeric vesicles. We have also investigated the encapsulation of both hydrophilic and hydrophobic fluorescent probes by these stimuli-responsive polymeric vesicles and the use of light as an external stimulus to trigger the release of the probes. The LDBCs are composed of a 2000 g mol−1 poly(ethylene glycol) (PEG) linear segment linked to a fourth generation 2,2-di(hydroxymethyl)propionic acid (bis-MPA) based dendron with 4-isobutyloxyazobenzene units at the periphery. By tuning the chemical structure of the azobenzene moieties, a specific LDBC has been identified that forms stable vesicles in water as it is clearly revealed by TEM and Cryo-TEM images. Encapsulation of both hydrophobic and hydrophilic molecules by these vesicular self-assemblies has been investigated by fluorescence analysis as well as the release of the loaded probes triggered by low intensity UV illumination, which is related to trans-to-cis isomerisation of the azobenzene moieties. Thus, the potential of these photo-responsive vesicles as light-responsive nanocarriers is demonstrated.
The apparent activation energy and relaxation volume from the point of view of Adam–Gibbs theory

The temperature and pressure dependence of the glass-transition process is discussed on the basis of the molecular Adam–Gibbs equation for the relaxation time. An equation for measuring the temperature and pressure dependence of the Adam–Gibbs size of the cooperative rearranging region is suggested. The apparent activation energy and the apparent relaxation volume by this equation are presented as the product of the activation energy and the activation volume per basic molecular kinetic unit respectively with the size of the cooperative unit to the second power. In this way, for the first time, an equation for measuring the activation volume of a basic molecular kinetic unit involved in the cooperative molecular dynamics is obtained. The isobaric and the isothermal activation volume of a basic molecular species (BMS) measured by this equation correlate with the molar volume of the liquid. From the experimental results it follows that the size of the cooperatively rearranging region at isothermal conditions increases with pressure until at the glass-transition pressures it reaches an apparent limit. On the basis of the activation volume measured per BMS, a method for evaluating their volume in liquids and their number in molecules or in repeated units in polymers is suggested. By this method, for the first time, from a relaxation experiment, the basic kinetic units in several molecular glass-forming liquids are found to be close to the fragments of the monomer segments or molecules known in thermodynamics as Wunderlich's beads.
Burner Development and Operability Issues Associated with Steady Flowing Syngas Fired Combustors

This article addresses the impact of syngas fuel composition on combustor blowout, flashback, dynamic stability, and autoignition in premixed, steady flowing combustion systems. These are critical issues to be considered and balanced against emissions considerations in the development and operation of premixed combustors. Starting with blowout, the percentage of hydrogen in the fuel is suggested to be the most significant fuel parameter, which is more fundamentally related to the hydrogen flame's resistance to stretch induced extinction. Turning to flashback next, it is shown that multiple flashback mechanisms are present in swirling flows, and the key thermophysical properties of a syngas mixture that influence its flashback proclivity depend upon which flashback mechanism is considered. Flashback due to turbulent flame propagation in the core flow and the interaction of heat release with pulsations are less critical, whereas flame propagation in boundary layers and flashback due to the interaction of the heat release with vortex breakdown dynamics are most significant. Then, combustion instability is considered. The key flame parameter impacting the conditions under which instabilities occur is the spatial distribution of the flame. As such, fuel composition influences dynamics through impacts upon flame speed and the flame stabilization point. Furthermore, certain syngas fuel compositions are not more inherently stable than others – rather, each mixture has particular islands in the parameter space of, e.g., velocity and fuel/air ratio, at which instabilities occur. Changes in fuel composition move these islands around but do not necessarily eliminate or introduce instabilities. Relative to autoignition, measurements indicate that the ignition delay time exceeds typical premixer residence times, though by a substantially less margin than suggested by the calculations. Recent experiment work suggest that current detailed kinetic mechanisms developed for hydrogen/carbon monoxide ignition overestimate the ignition delay time, indicating the need for additional kinetic work in the low temperature, high pressure regime.
Growth and biomass partitioning in zinc‐toxic bush beans

Abstract Bush bean plants (Phaseolus vulgaris L.) were grown during the exponential growth phase in nutrient solution containing 2, 6.6, 9.6 or 13.5 μM Zn. At six different harvest intervals samples were taken for dry weight and Zn content determinations. The primary growth data were fitted to exponential curves, from which the relative growth rates (RGR) and the net assimilation rates (NAR) were derived. With the RGR data the biomass partitioning coefficients of the different organs were calculated. Zinc toxicity generally decreased both the NAR and the growth of all organs, and increased their Zn contents. The relative root expansion rates (RER) and the relative root dry weight growth rates were the most affected parameters, while the leaf expansion rates and the stem dry weight growth rates were hardly affected. The biomass partitioning coefficients indicate that after long‐term exposure to toxic Zn levels the root growth is more affected than the photosynthetate production. This leads to a relative in.
Removal of Wood Components During Chlorite Delignification of Black Spruce

The pattern of component removal has been studied for black spruce during delignification by acidified sodium chlorite at 70 °C. Special emphasis was placed on the determination of the acid soluble portion of lignin remaining in the sample.It was found that the chlorite procedure is selective in removing lignin only during the first 60% of delignification. At later stages of delignification some glucomannan is dissolved. A so-called holocellulose of 70% yield is thus composed of about 40% cellulose, 13% glucomannan and galactan, 12% xylan and other carbohydrates, and 5% lignin (all based on the original wood).
Concentrations of 60 elements in the soil solution as related to the soil acidity

Little is known about solubility and soil solution concentrations of most elements occurring in the solid phase of soils. This study reports changes in solution concentrations of 60 mineral elements following CaCO3 addition to a moderately acid semi‐natural soil, and possible mechanisms accounting for the differing solubility patterns as related to soil acidity are discussed. Soil solutions were obtained by high‐speed centrifuging and ultrafiltration (0.2 μm) of samples at 60% water‐holding capacity of the A horizon of a Cambisol developed from a shale–gneiss moraine and supplied with CaCO3 at 20 rates to yield a soil solution pH range of 5.2–7.8. Concentrations of elements were determined in the solutions by ICP‐AES or (for most elements) ICP‐MS. Several distinct patterns of soil solution concentrations as a function of soil solution pH were demonstrated. Positively related to pH and CaCO3 supply were soil solution concentrations of As, Br, Mo, S, Sb, Se, U, and W, and to a lesser degree, Co, Cr, Hg, Mg, and Sr. Inversely related to pH were concentrations of Al, B, Ba, Bi, Cs, Ce, Eu, Ga, Ge, Fe, Li, K, Rb, Na, Th, and Ti; less distinctly inversely rated were Dy, Er, Gd, Hf, La, Lu, Mn, Nd, Pr, Sm, Sc, Si, Tl, Tm, and Yb. ‘U‐shaped’ relationships to pH were demonstrated for the concentrations of Ag, Cd, Nb, Ni, P, V, and Zr. There were no or irregular relations between pH and concentrations of Be, Cu, Ho, Pb, Ta, and Tb. Differences between elements in their soil solution concentrations as related to total (HNO3‐digestible) concentrations and the solubility of organic C were also treated. Increasing the pH of a soil by adding CaCO3 changes the solubility of most mineral elements substantially, the several distinct patterns observed being governed by, for example, ionic properties and charge, affinity for organic compounds, and pH‐dependent formation and solubility of complexes.