Miracle-dz/UniFAR-FTUs huggingface dataset:
The Formation of Manganese and Cobalt Ferrites by the Air Oxidation of Aqueous Suspensions and Their Properties

Manganese and cobalt ferrites were prepared by the air oxidation of aqueous suspension of Fe(OH)2 and either Mn(OH)2 or Co(OH)2 at 50–80 °C. In alkaline suspensions, all the metal ions are transformed into spinel ferrites, MxFe3−xO4 (M=Mn or Co), by a suitable combination of the oxidation temperature and the concentration of the excess NaOH. Both manganese and cobalt ferrites consist of ferromagnetic particles (ferrite(A)) when x is smaller than 1.3, nonferromagnetic particles (ferrite(B)) when x is larger than 2, and mixtures of the two in the intervening range. The contents of Mn or Co, both in a solid solution of hydroxides, Mx⁄3Fe1−x⁄3(OH)2, and in ferrite, increase with the progress of the formation of the ferrite(A) caused by oxidation. The formation of the ferrite(B) begins when x in the solid solution reaches 2. Each particle in the ferrite(A) is less homogeneous in comparison with that in the ferrite prepared by a solid-state reaction, although with the same composition. The difference in the hom.
Combined free and forced convection flow past a vertial porous plate

Local similarity solutions of the forced and free convection flow past a semi-infinite vertical porous plate have been obtained numerically. Velocity and temperature profiles are shown for air (Pr = 0.72) and for different values of Gr (Gr > 0, cooling of the plate and Gr 0, suction, fw <0, injection). the effects of these parameters are discussed.
Application of High-Performance Liquid Chromatography to the Determination of Ascorbic Acid in Marine Plankton

Abstract Reversed-phase and anion-exchange high performance liquid chromatography, which offer a great potential for the measurement of vitamin C in plankton, were compared using different columns and reagents. A method using a polystyrene divinyl benzene column is described that has been utilized for rapid separation and quantification of L(+)-ascorbic acid in marine plankton.
Miniemulsion Polymerization with Arrested Ostwald Ripening Stabilized by Amphiphilic RAFT Copolymers

We describe a method and conditions for the preparation of monodisperse latex particle dispersions using low molecular-weight, amphiphilic styrene-b-acrylic acid macro-RAFT diblock copolymers as sole stabilizers. The macro-RAFT copolymers are soluble in styrene monomer droplets when the acrylic acid is in its neutral, protonated form, but adsorb irreversibly at the interface between the monomer droplets and the aqueous phase to form an insoluble monolayer when conditions favor deprotonation. Droplets thus stabilized exhibited no coarsening by Ostwald ripening over at least several days. Polymerization yielded a one-to-one correspondence between the size of the initial droplets and the resultant latex particles, consistent with ideal miniemulsion polymerization, when the least labile macro-RAFT stabilizer was used. GPC analysis of molecular weights showed that in all cases the polymerization remained under RAFT control. The approach described enables true miniemulsion polymerization to proceed in the absen.
THE DILATANCY CAUSED BY SHEARING MOTION

The disruption of molecular packing caused by shear motion in a fluid depends not only on the velocity gradient in the pertinent region but also on how fast the molecules in the given material respond to any change in this gradient. So the author has replaced this gradient with the dilatancy, introducing it into the formula for dE, where E is the specific internal energy. Then combining the known relationship between the rate at which the shearing can relax, the author has derived a relationship between the dilatancy and the corresponding steady state rate of shear. Measurements of the dilatancy in a fluid undergoing a known rate of shear can then yield a value for the relaxation time. A similar treatment of heat flow yields a relationship between the dilatancy and the corresponding steady-state temperature gradient.
A Microfluidic Approach for a Continuous Crystallization of Drug Carrier Nanoparticles

Solid lipid nanoparticles (SLN) as a new generation of drug carrier systems for pharmaceutical applications are currently under intensive investigation. They can be prepared by melt-homogenization of a matrix lipid in surfactant-containing aqueous media. In the corresponding production sequence, the crystallization of the resulting lipid droplets to solid nanoparticles is a crucial step for reproducible product properties. Hitherto, melt crystallization in these dispersions is usually performed in a batchwise process under poorly defined cooling conditions, without much regard to the well-known aspects of heat transfer, homogeneity in the product mixture, and precise process control. In addition, these setups often only allow the application of low cooling rates. The use of high, well-defined cooling rates would, however, offer very interesting new possibilities for the manufacturing of such drug carrier systems. Due to their small volumes and superior heat and mass transfer performance, microfluidic devices ensure a precise setting and control of the optimum process conditions. In this study, a microfluidic process for the continuous melt crystallization of SLN suspensions is established, allowing for high and well-defined cooling rates. For various cooling rates, the crystallized SLN were analyzed by differential scanning calorimetry, X-ray diffraction, laser diffraction, and photon correlation spectroscopy. The samples were also analyzed after well-defined storage times in order to investigate the stability of the suspensions.
Proton Transfer in the Adenine-Thymine Base Pair

The transition state for the double proton transfer in the Watson-Crick type of adenine-thymine (AT) base pair was located by using the ab initio HF MINI-1 full gradient optimization technique. Allowing the geometry to relax in the calculation of the double proton transfer and interaction energies results in a substantial lowering of the energetic difference between AT and its imino-enol tautomer, A * T * . An energy barrier of 9.7 kcal/mol was calculated for the lowest energy reaction path from the canonical AT structure to the rare tautomeric A * T * structure, whereasa barrier of only 0.2 kcal/mol occurred for the reverse reaction
Adsorption of arsenic in aqueous solution by RH-Fe-MCM-41

RH-Fe-MCM-41 adsorption efficiency and capacity were examined with arsenic in lower concentrations in aqueous solution under varying pH values. The adsorption of arsenite (As3 + ) and arsenate (As5 + ) by RH-Fe-MCM-41 at the molar ratio of Si/Fe 10 gave removal efficiencies of 47% and 99% for As3 + and As5 + , respectively, in the 100–1,000 μg l−1 concentration range. For the adsorption test of arsenic the best conditions were found to be an equilibrium time of 12 h at pH 7 for As3 + and 2 h at pH 4 for As5 + . The adsorption capacity by the Langmuir constants ( Q m) for As3 + and As5 + were 416.67 μg g−1 and 277.78 μg g−1, respectively, while the Freundlich constants ( K F) were 0.583 μg g−1 for As3 + and 112.87 μg g−1 for As5 + . The fit for As5 + was good with both the Langmuir and Freundlich isotherms by considering the R 2 values, which were quite similar (0.916 and 0.912); As3 + fit well only with the Langmuir isotherm. The impregnation of iron (Fe3 + ) into the RH-Fe-MCM-41 structure increases the adsorption capacity of As3 + and As5 + both by oxidizing As3 + to As5 + and by co-precipitation with As5 + .
The growth and development of the major pelvic ganglion of the female rat in normal and disease conditions

The development of the pelvic ganglion was studied in female rats from birth to 90 days (adult) by electron microscopy, by morphometry on plastic sections and by histochemistry on whole-mount preparations. The pelvic ganglion of the adult female Sprague-Dawley rat had a volume (measured by the Cavalieri method) of 210 million μm3 and contained a total of 8185 ± 2147 neurons (counted by full reconstruction of three ganglia), which ranged in size from 1100-24500 μm3 (average 4942). In the newborn, the pelvic ganglion had similar topographical relations with surrounding organs as in the adult, was immersed in loose connective tissue rather than possessing a proper capsule, and had a volume about one quarter that in the adult. The ganglion was made of neurons, non-neuronal cells and blood vessels but it contained notably less collagen and fewer nerve bundles than in the adult; in contrast, SIF cells were abundant. Neuronal sizes ranged from 350 to 2250 m3 with an average of 596. The number of neurons was not evaluated at the developmental stages, but other studies have shown that in the female rat neurons are markedly more numerous in the newborn than in the adult. Intermediate stages in ganglion volume and neuronal size growth were found at 3, 7, 14, and 30 days. The neurons at birth were similar to those of the adult in shape; however, they lacked a glial sheath and had extensive membrane to membrane contacts with each other and with SIF cells. Only few Schwann cells were present and many nerve bundles were devoid of them. The intracellular organelles observed at birth were the same as those in the adult, but some, notably microtubules, were less abundant. Both axo-dendritic and axo-somatic synapses were observed from the time of birth. The growth of the pelvic ganglion was also investigated in experimental conditions of polyuria. For this, Brattleboro rats, with congenital diabetes insipidus, and their control parent strain Long-Evans, were used. In the adult Brattleboro rat there was hypertrophy of pelvic ganglion neurons and of urinary bladder: bladder weight was increased 4 fold and bladder capacity 3 fold. The muscle coat was increased in extent but not in thickness over the controls, and the muscle cells much enlarged in size. Brattleboro rats studied at 14 days of age were already displaying significant enlargement of bladder and pelvic ganglion over age matched controls.
Hydrogen isotopic substitution of solid methylamine through atomic surface reactions at low temperatures: A potential contribution to the D/H ratio of methylamine in molecular clouds

We experimentally studied hydrogen (H)–deuterium (D) substitution reactions of solid methylamine (CH3NH2) under astrophysically relevant conditions. We also calculated the potential energy surface for the H–D substitution reactions of methylamine isotopologues using quantum chemical methods. Despite the relatively large energy barrier of more than 18 kJ mol−1, CH3NH2 reacted with D atoms to yield deuterated methylamines at 10 K, suggesting that the H–D substitution reaction proceeds through quantum tunneling. Deuterated methylamines reacted with H atoms as well. On the basis of present results, we propose that methylamine has potential for D enrichment through atomic surface reactions on interstellar grains at very low temperatures in molecular clouds. D enrichment would occur in particular in the methyl group of methylamine.
Protein and Nanoparticle Characterisation Using Light Scattering Techniques

The technique of dynamic light scattering is well suited to the measurement of the size of colloidal dispersions. Traditionally, measurements of large particle sizes or particles that are highly scattering would require high dilution of the sample in order to avoid multiple scattering effects. Conversely, measurement of very small and/or poorly scattering particles or samples that are very dilute are difficult unless high‐powered lasers are used. These problems have been addressed in a light scattering instrument incorporating novel non‐invasive backscatter optics (NIBS). This novel optic arrangement maximises the detection of scattered light while maintaining signal quality. In addition to the increased size and concentration range for DLS applications, the increased sensitivity obtained from this optical arrangement also allows for the determination of absolute molecular weight using static light scattering measurements. Accurate molecular weight measurements can be achieved at a single scattering angle for molecules that do not show any angular dependence in their scattering intensity. This paper describes the advantages of using backscatter optics and illustrates the capabilities of the technology by reporting results of measurements from various applications.
Comment on the accuracy of absolute electron-impact ionization cross sections for molecules

Electron impact ionization of molecules has been studied extensively in many laboratories and it is perhaps surprising therefore that uncertainty in the values of many cross sections has persisted. In an effort to rectify this situation absolute partial and total electron-impact ionization cross sections have been measured in this laboratory for a range of molecular targets, including H2, N2, O2, CO, NO, CO2, CH4, and SF6. These total cross sections for these molecules are compared here to those measured by Rapp and Englander-Golden, which have long been widely adopted as the de facto standard. The excellent agreement observed between these two independent data sets would seem to warrant a high level of confidence in them, and in the corresponding partial cross sections determined in this laboratory.
Update on the WFC3/UVIS Stability and Contamination Monitor

The photometric throughput of WFC3 is measured periodically throughout the year to evaluate its stability as a function of time and wavelength, as well as to check for the presence of possible contaminants in the UVIS channel. These monitoring data consist of observations of the white dwarf spectrophotometric standard GRW+70d5824, taken in a subset of key lters covering 200-600 nm, with F606W and F814W acting as controls on the red end. Here we analyze the observations from 2009 to mid-2014. No contamination eects have been detected, though small photometric drifts are evident: a slight increase in throughput in the UV lters ( 0.1%/year) and slight decreases in throughput in red and visible lters ( 0.2%/year and 0.4%/year, respectively).
N-Methylamino acids in peptide synthesis. V. The synthesis of N-tert-butyloxycarbonyl, N-methylamino acids by N-methylation

The preparation of enantiomerically pure N-tert-butyloxycarbonyl,N-methylamino acids by N-methylation of the parent amino acid derivatives using sodium hydride and methyl iodide in tetrahydrofuran at room temperature is described for neutral amino acids including O-benzyl-protected threonine and tyrosine. Methylation of the O-benzylserine derivative under these conditions gives the N-methyldehydroalanine derivative. The β-elimination is completely suppressed, giving the corresponding N-methylserine derivative when the reaction is carried out at 5 °C. Other related data on N-methylation and N-methylamino acid derivatives are presented.
SYNTHESIS OF MIXED OLIGOMERIC HETEROARYLENES CONTAINING FURAN, THIOPHENE, AND SELENOPHENE RINGS; THEIR UV SPECTRA AND OXIDATION POTENTIALS

Abstract Mixed oligomeric five-membered heteroarylenes 3a-f and 4a-e have been prepared by cross-coupling reaction of the Grignard reagents 2 derived of the appropriately substituted thiophenes 1 with either the 2-bromoheteroarylenes or the 2,5-dibromoheteroarylenes derived of furan, thiophene, and/or selenophene respectively. The UV spectra and oxidation potential of compounds 3a-f and 4a-e are discussed on the basis of co-planarity.
CH3NH3Cl-Assisted One-Step Solution Growth of CH3NH3PbI3: Structure, Charge-Carrier Dynamics, and Photovoltaic Properties of Perovskite Solar Cells

We demonstrate a novel one-step solution approach to prepare perovskite CH3NH3PbI3 films by adding CH3NH3Cl (or MACl) to the standard CH3NH3PbI3 precursor (equimolar mixture of CH3NH3I and PbI2) solution. The use of MACl strongly affects the crystallization process of forming pure CH3NH3PbI3, leading not only to enhanced absorption of CH3NH3PbI3 but also to significantly improved coverage of CH3NH3PbI3 on a planar substrate. Compared to the standard one-step solution approach for CH3NH3PbI3, using MACl improves the performance of CH3NH3PbI3 solar cells from about 2% to 12% for the planar cell structure and from about 8% to 10% for the mesostructured device architecture. Although we find no significant effect of using MACl on charge transport and recombination in mesostructured perovskite cells, the recombination resistance for planar cells increases by 1–2 orders of magnitude by using MACl. These results suggest that this new one-step solution approach is promising for controlling CH3NH3PbI3 growth to ach.
Salt effects on the phase transition of ionic gels

An ionized acrylamide gel is found to undergo a discrete phase transition in equilibrium volume upon varying the salt concentration in the solution. The salt concentration required for the transition depends strongly on the valency of the positive salt ion added to the solution. In certain cases the concentration at the transition is many thousand times larger for monovalent ions than for divalent ions. A simple theoretical consideration of the osmotic pressure of the ions can explain the phenomenon.
Structural dipoles at interfaces between polar II-VI semiconductors CdS and CdTe and non-polar layered transition metal dichalcogenide semiconductors MoTe2 and WSe2

The electronic structure of heterojunctions between II-VI semiconductors (CdS, CdTe) and layered transition metal dichalcogenide semiconductors (MoTe2, WSe2) were investigated by soft x-ray photoelectron spectroscopy. The interfaces were formed sequentially by molecular beam epitaxy (MBE) of the II-VI semiconductors on van der Waals (0001)-surfaces of layered compound single crystals. The II-VI semiconductors grow with their polar hexagonal axis ([111] for CdTe, [0001] for CdS) parallel to the non-polar substrate [0001]-axis, without evidence for lattice distortions as prooved by TEM and LEED. Band offsets were determined from soft x-ray photoelectron spectra. Large substrate independent interface dipoles of 1.2 eV for CdS and 0.8 eV for CdTe were determined. The deviation of experimental band offsets from the electron affinity rule prediction is described by a simple model which takes the polarity of the grown interfaces into account.
Evaluation of Phytochemical, Pharmacognostical and Antibacterial Activity of Garcinia Gummicutta Leaves

Summary Evaluation of the leaves of Garcinia gummicutta (Guttiferae) has been carried out the present study. This study was analysis of macroscopically characters, microchemical tests, behavior on the powder, treatment with different chemical reagents, physical constant values, fluorescence analysis and preliminary phytochemical investigation. The conclusion of the present reports on the alkaloid, terpenoid, steroid, oil, catachin and phenol were found to be leaves extract of G. gummicutta leaves and its on the active compounds may be acted as antibacterial activity.
Photoswitchable Antigen−Antibody Interactions Studied by Impedance Spectroscopy

A thiolated dinitrospiropyran (1a) is assembled as a monolayer onto a Au electrode. The monolayer exhibits reversible photoisomerizable properties, and irradiation of the 1a monolayer state, 360 nm 495 nm, regenerates the 1a monolayer electrode. The 1a monolayer interface acts as antigen for the dinitrophenyl antibody, DNP-Ab, while the 1b state lacks an affinity for DNP-Ab. This stimulates the association of the antibody to the 1a monolayer interface, while photoisomerization of the monolayer to the 1b state allows one to wash off DNP-Ab and regenerate the 1a monolayer assembly by a secondary illumination process. The photoisomerization of the monolayer interface and the binding or dissociation of DNP-Ab to and from the photoisomerizable monolayer are studied by impedance spectroscopy, in the presence or absence of a solubilized redox probe. The derived equivalent circuits ena.
Soot Activation Energy for a Xylene-Fueled CVD Reactor

The past attempts of Arrhenius plots of carbon nanotube (CNT) yield (or CNT length) to obtain the overall activation energy for CNT formation under changing reaction temperature conditions have created substantial errors. Here we propose an inverse method to accurately account for the effect of temperature on gas-phase reactions and species composition. The overall activation energy of soot formation for a xylene-based CVD reactor was calculated and successfully compared with the measured gas-phase concentration data. Our proposed inverse method is expected to help improve the performance of CVD reactors and optimize its design.
Longitudinal electron diffusion coefficients in gases: Noble gases

Values of the ratio of the longitudinal diffusion coefficient to mobility DL/μ for electrons in He, Ar, Kr, and Xe are derived from current waveforms obtained during earlier measurements of electron mobility. The electric field to gas density ratios E/N cover the wide range of 10−3 to 20 Td, thereby bridging previous experiments at low E/N to recent experiments at high E/N. Here 1 Td=1×10−21 V m2. The corresponding DL/μ values range from 0.0066 eV for thermal electrons at 77 K to 10 eV. In addition to the well‐known peak in DL/μ for Ar at E/N between 0.01 and 0.1 Td caused by the Ramsauer minimum in the momentum transfer cross section, we find previously unreported low‐energy peaks in DL/μ vs E/N in Kr and Xe and previously unreported pronounced leveling‐off in DL/μ at E/N≳8 Td in Ar, Kr, and Xe. Calculations of transport coefficients using numerical solutions of the Boltzmann equation and cross section sets in the literature give good agreement with experiment from E/N producing thermal electrons up to a.
Theory of the Phase Transition between Helix and Random Coil in Polypeptide Chains

The transition between the helical and randomly coiled forms of a polypeptide chain is discussed by reference to a simple model that allows bonding only between each group and the third preceding. Two principal parameters are introduced, a statistical parameter that is essentially an equilibrium constant for the bonding of segments to a portion of the chain that is already in helical form, and a special correction factor for the initiation of a helix. A third parameter which specifies the minimum number of segments in a random section between two helical portions has only a minor effect on the results. The partition function for this model is handled in two alternative ways, either as a summation suitable for short chains, or in terms of the eigenvalues and eigenvectors of a characteristic matrix; the latter is more suitable for long chains. A transition from the random to the helical form is encountered as either the bonding parameter or the chain length is increased. The critical value of the bonding pa.