Miracle-dz/UniFAR-FTUs huggingface dataset:
Rotational-Echo, Double-Resonance Nuclear Magnetic Resonance Spectroscopy

The conformation of ( 1-13C,'5N)acetyl-~-carnitine is studied by rotational-echo, double-resonance (REDOR) NMR experiments. The REDOR results show that acetyl-L-carnitine adopts an extended molecular conformation in the solid state for both crystalline and lyophilized samples. These findings are in contrast to various X-ray-determined structures of racemic acetylcarnitine showing folded conformations.
Deep trapping centers in crosslinked polyethylene investigated by molecular modeling and luminescence techniques

Space charge in crosslinked polyethylene (XLPE) has been detected under both ac and dc fields. Its role in electrical aging and breakdown is recognized, but not deeply understood. It is thought that identification of the trapping centers in this material would help improve the modeling of conduction and electrical aging as well as making possible the design of crosslinked materials with improved properties. We have developed theoretical and experimental approaches to this problem which emphasize the role of chemical traps acting as deep trapping centers. Molecular modeling is used to estimate the trap depth for negative and positive charge carriers associated with the main by-products of crosslinking reactions (using dicumyl peroxide as a crosslinking agent) since their aromatic structure makes them candidates for deep traps. Calculations on acetophenone, n-methyl styrene and cumyl alcohol show that they indeed can act as deep traps. Because such deep traps can act as recombination centers, their involvement in charge trapping can be checked in specially designed luminescence experiments. In our experiments, charges of both polarities are generated at the surface of the material under study by using a non-reactive cold plasma in helium. The analysis of the decay kinetics and emission spectrum of the subsequent luminescence allows us to define unambiguously the time range in which charge recombination is the dominant excitation process of the luminescence. The emission spectra obtained within this time range provide the optical fingerprint of chromophores acting as deep traps in the material. The low-density polyethylene (LDPE) doped with crosslinking byproducts and XLPE (film and cable peeling) have been investigated. Their role in charge trapping is apparent in the luminescence experiments and in space charge distribution analysis. In thermally treated XLPE, it is shown that other species strongly bonded to the polymer chain are also able to trap electrical charges.
Considerations in the Design of Materials for Solar‐Driven Fuel Production Using Metal‐Oxide Thermochemical Cycles

With demand for energy increasing worldwide and an ever‐stronger case building for anthropogenic climate change, the need for carbon‐neutral fuels is becoming an imperative. Extensive transportation infrastructure based on liquid hydrocarbon fuels motivates development of processes using solar energy to convert CO2 and H2O to fuel precursors such as synthesis gas. Here, perspectives concerning the use of solar‐driven thermochemical cycles using metal oxides to produce fuel precursors are given and, in particular, the important relationship between reactor design and material selection is discussed. Considering both a detailed thermodynamic analysis and factors such as reaction kinetics, volatility, and phase stability, an integrated analytical approach that facilitates material design is presented. These concepts are illustrated using three oxide materials currently receiving considerable attention: metal‐substituted ferrites, ceria, and doped cerias. Although none of these materials is “ideal,” the tradeoffs made in selecting any one of them are clearly indicated, providing a starting point for assessing the feasibility of alternative materials developed in the future.
Determination of Metal Dispersion of Pt/CeO2 Catalyst by CO-pulse Method

2･g −1 ) gave reasonable ratios of adsorbed CO to total Pt. However, the CO/Pt ratio exceeded unity on high surface area CeO2 support (66.7 m 2 ･g −1 ), suggesting adsorption of CO on the CeO2 surface. Reduction of the catalyst under milder conditions at 373 to 573 K for 15 min to 5 h gave constant CO/Pt ratio of 0.40 within a reasonable experimental error. The mean particle diameter estimated from this CO/Pt ratio on the assumption of spherical particles closely agreed with a volume-area mean diameter measured by TEM. It was concluded that the dispersion of Pt supported on CeO2 can be measured by lowering the reduction temperature to suppress the effect of the CeO2 support.
Study on Surface Tension for Non-polar and Associating Fluids Based on Density Functional Theory

A method for the prediction of surface tension of non-polar and associating fluids has been developed based on the density functional theory (DFT). The WCA perturbation theory and the SAFT are used to establish the equation of state (EOS). The adjustable parameters are correlated by simultaneously fitting the saturated vapor pressure and the liquid density data with the EOS. The local density approximation (LDA) is applied to the reference term and the mean field approximation (MFA) is used for perturbation term. The density profile is obtained by minimizing the grand potential functional. The surface thickness is calculated by “10%-to-90%-width” method. By use of the regressed parameters in EOS and the obtained density profile, the surface tensions for 13 non-polar fluids and 10 associating fluids are predicted satisfactorily.
The Function of Bandrowski' Base in Hair Dyeing

Synopsis--Proposals for the structure of Bandrowski's Base (BB) are reviewed, and it is concluded that the structure originally proposed by Green is the correct one. The role of BB in dyeing of human hair was studied by examining hair dyed with p-phenylenediamine and hydrogen peroxide. Solvent extraction of dyed hair or decomposition by dilute alkali yielded mixtures which contained little or no BB when they were examined by thin-layer chromatography. Based on these experiments, it is concluded that BB is not the main colorant of hair dyed with p-phenylenediamine.
On Mixture Nonlinear Time-Series Modelling and Forecasting for Arch Effects

In the class of Nonlinear time-series models, Gaussian mixture transition dis tribution (GMTD) and Mixture autoregressive (MAR) models may be em ployed to describe those data sets that depict sudden bursts, outliers and flat stretches at irregular time-epochs. In order to capture volatility explicitly, recently a new family, viz. M AR-Autoregressive conditional heteroscedastic (MAR-ARCH) has been introduced in the literature. In this paper, these three families are studied by considering weekly wholesale onion price data during April, 1998 to March, 2002. Presence of ARCH in detrended and de seasonalised series is tested by Naive-Lagrange multiplier (Naive-LM) test. Estimation of parameters is done using Expectation-Maximization (EM) al gorithm and best model from each family is selected on basis of Bayesian information criterion (BIC). The salient feature of work done is that, for selected models, formulae for carrying out out-of-sample forecasting up to three-steps ahead have been obtained theoretically, perhaps for the first time, by recursive use of conditional expectation and conditional variance. In respect of out-of-sample data, results derived enable us to compute best predictor, prediction error variance, and predictive density. It is concluded that a two-component MAR-ARCH provides best description of the data for modelling as well as forecasting purposes.
pH-Controlled multiple-drug delivery by a novel antibacterial nanocomposite for combination therapy

Nanoparticle-based combination therapies have shown several unique features that are untenable in traditional chemotherapy. The present attempt intends to prepare a novel smart multifunctional drug delivery system based on cationic silica based polymer–clay nanocomposites for combination cancer therapy. The intercalation of silica based copolymers into montmorillonite (MMT) was achieved through an ion exchange process. The structure of the resulting nanocomposites was characterized by means of XRD, FT-IR, TG-DTA and SEM. This nanocomposite was used for multiple drug delivery of two anticancer drugs doxorubicin (DOX) and methotrexate (MTX) and an antibacterial agent ciprofloxacin (CIP). The in vitro antimicrobial activity of nanocomposites and CIP loaded nanocomposites was tested in growth inhibition of Escherichia coli and Pseudomonas aeruginosa bacteria by the MIC method. Furthermore, the potential antitumoral activity of this combined therapy system was evaluated against T47D cell lines by MTT assay and qRT-PCR. XRD results proved successful interaction of MMT with the cationic silica based copolymer. The nanocomposites showed an encapsulation efficiency of about 95% for the mentioned drugs. The cumulative in vitro release of the DOX/MTX/CIP-loaded nanocomposites revealed that the individual drug can undergo controlled release with the ability to distinguish between tumor tissues. Cell viability tests additionally confirmed that the dual-administration of DOX with MTX had a higher cytotoxicity to the mentioned cells in comparison with free dual drug forms. The in vitro antimicrobial results revealed good antimicrobial activities of both the blank nanocomposite and CIP loaded nanocomposite. Therefore, the dual anticancer drug-loaded antibacterial smart nanocomposite has the potential to be used for combination cancer therapy.
FUNCTIONALITY COMPARISON BETWEEN NATURAL AND SYNTHETIC POLYMERS IN DEVELOPMENT AND IN-VITRO CHARACTERIZATION OF GASTRO RETENTIVE FLOATING DRUG DELIVERY SYSTEM OF ATORVASTATIN CALCIUM

Article history Gastroretentive floating tablets of atorvastatin calcium were formulated by using synthetic and natural polymers like HPMC and guar gum, Xanthan gum, karaya gum, aleovera powder respectively in order to enhance the bioavailability (14%) of atorvastatin calcium a drug used in the treatment of dyslipidemia and for the prevention of cardiovascular diseases. Floating tablets were prepared by employing potassium bicarbonate as a gas generating agent, and Polyvinylpyrrolidone K-30 as binder and excipients like Micro crystalline cellulose, dibasic calcium phosphate, magnesium stearate and talc. Tablets were prepared by direct compression method and the prepared tablets were evaluated for pre-compression characteristics and post- compression characteristics like weight variation, hardness, thickness, friability, swelling index, floating lag time, floating duration and in-vitro dissolution studies. FTIR studies for the drug and polymers shows that they are compatible. The precompression parameters indicate good flow properties for the powder. The tablets formulated with synthetic polymers remained buoyant for more than 6hrs and those with natural polymer remained for more than 8hrs in the release media. The optimized formulation F6 remains floating for more than 12 hrs and shows a sustained release of drug and percentage of drug release after 12 hrs was found to be 95.92%. The drug release mechanism for the optimized formula is by Higuchi's model (R 2 = 0.9987). DSC studies have shown that drug is stable in the formulation. It is concluded that the natural polymers are more effective than the synthetic polymers in the development of gastroretentive dosage forms and thus enhances the solubility and bioavailability of the drug.
Strengthening Adult Career Pathways in Minnesota: A Professional Development Cohort for Managers.

Establishing adult career pathways is challenging, complex work. In Minnesota, a new professional development initiative provides ABE managers with a facilitated, supported, yearlong cohort as they work to create or strengthen a career pathway program in collaboration with WIOA partners in their localities. In this article, the rationale, design, and outcomes of this professional development activity are outlined. Key features include an experiential learning approach, a mix of face-to-face and online interaction and presentation, peer partners, coaching calls, goal-setting, and local action steps.
Synthesis and Characterization of Conjugated Mono- and Dithiol Oligomers and Characterization of Their Self-Assembled Monolayers

The characterization of self-assembled monolayer molecular arrays, which serve as active layers in electronic devices, is an important step toward understanding molecular-scale electronics. To correlate the properties of self-assembled monolayers with their molecular structures, a series of π-conjugated mono- and dithiols and aromatic dithiols with an oxygen or sulfur atom between two aromatic units have been designed and synthesized. Their optical properties were determined by UV−vis spectroscopy. Their self-assembled monolayer films on gold surfaces were characterized by cyclic voltammetry, grazing incidence Fourier transform infrared spectroscopy (GI-FTIR), and contact angle and ellipsometry measurements. Increasing the chain length from two to four phenyl rings showed a more than linear increase of the intensity of the aromatic CC ring stretch modes in GI-FTIR, indicating that the longer p-phenylene system is oriented toward the surface normal. Similar to oligophenylenes, when the number of repeat uni.
Assembly of Glucose Oxidase and Different Polyelectrolytes by Means of Electrostatic Layer‐by‐Layer Adsorption on Thiolated Gold Surface

A rational strategy for the construction of a bioelectrocatalytic architecture by means of alternate electrostatic adsorption is described. Multilayer films containing glucose oxidase (GOx) and different polyelectrolytes were assembled onto a thiolated-gold surface and the resulting bioelectrode was used for glucose biosensing. The supramolecular multistructure was prepared by assembling polyethylenimine and Nafion (as anti-interference barrier), followed by the adsorption of polyethylenimine and DNA (as stabilizing film) and finally by the alternate deposition of polyethylenimine and glucose oxidase (as a biocatalytic layer). The influence of the deposition time and concentration of polyelectrolytes, organization and number of layers on the sensitivity and selectivity of the bioelectrode is discussed. The resulting enzymatic biorecognition layer exhibits very good analytical performance with a fast, sensitive (3.3±0.1)×104 nA M−1 and highly selective (0% interference for 6.0 mg % uric acid and 2.0×10−4 M ascorbic acid) response to glucose, demonstrating that the alternate electrostatic adsorption of conveniently selected polyelectrolytes allow a large improvement in the selectivity and sensitivity of a biosensor.
Viscoelastic behaviors and molecular motions of highly syndiotactic poly(vinyl alcohol) fibers

The viscoelastic behavior and molecular motion of highly syndiotactic poly(vinyl alcohol) (S-PVA) fibers with a dyad syndiotacticity (r) of 69% were studied by dynamic mechanical thermal analysis and wide-angle X-ray diffraction and compared with those of atactic poly(vinyl alcohol) (A-PVA) fibers with r = 54%. The βc dispersion, based on the molecular motion of the chain molecules in the crystalline regions, was observed for A-PVA around 120–140 °C, and the only primary (αc) dispersion was observed for S-PVA around 180 °C. The thermal expansion coefficients for the a and c axes of the A-PVA crystal changed discontinuously around 120 °C, which corresponded to the βc dispersion. For S-PVA, the coefficient for the (002) plane changed discontinuously around 100 °C, similarly to A-PVA, but that for the (100) plane remained unchanged between 20 and 220 °C. These results showed that the intermolecular hydrogen bonding of S-PVA was stronger in the direction of the a axis than in the other directions, suppressing the βc dispersion. The storage modulus and thermal expansion coefficient of the (020) plane (molecular axis) of S-PVA decreased markedly around 180 °C, and this indicated that the αc dispersion was due to the torsional motion of the molecular chains in the crystalline regions. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 800–808, 2004
Formation of Myofibrillar Fragments and Reversible Contraction of Sarcomeres in Chicken Pectoral Muscle

SUMMARY— As morphological changes occurred in the pectoral muscles of chicken carcasses during 48 hr storage at 5°C, two notable phenomena were observed: (1) fragmentation of myofibrils and (2) reversible or irreversible contraction of sarcomeres. When blendorized, myofibrils tend to break into small fragments composed of 1-4 sarcomeres with time post-mortem. It was also found that besides an irreversible post-mortem contraction of sarcomeres generally accepted, a reversible contraction can take place under particular conditions.
Characterization of Ge1-xTex chalcogenide thin films deposited by MOCVD for phase change memory applications

The Ge 1-x Te x chalcogenide thin films for phase change memory applications were prepared on TiAIN (30 nm)/ SiO 2 (100 nm)/Si substrates by metallorganic chemical vapor deposition (MOCVD) using Ge(allyl)4(Ge(C3H5)4), Sb(iPr) 3 (Sb(C 3 H 7 ) 3 ), and Te(tBu) 2 (Te(C 4 H 9 ) 2 ) precursors. The Ge 1-x Te x films were grown by the tellurium deposition at 230-250°C on Ge films deposited on a TiAIN electrode in the presence of Sb at 370°C. The Ge 1-x Te x film growth by the tellurium deposition on Ge films depends on both the tellurium deposition temperature and the deposition time. The Ge and Te in the films deposited on a confined structure of 500 nm in diameter and 200 nm in depth shows a homogeneous distribution, and their distribution was consistent with the films deposited on a planar structure.
Direct comparison of the rheology of model hard and soft particle glasses

The effects of particle softness and the role of the outer shell mechanics on the linear viscoelasticity and yielding behaviour of colloidal glasses are critically assessed using three different model colloidal particles: (i) sterically stabilized PMMA particles with model hard sphere interactions, (ii) core–shell microgels with a deformable PNIPAM outer shell and (iii) ultra-soft star-like micelles with inter-penetrable multi-arms. The volume fraction dependence of the elastic modulus and the yield stress reflects the softness of the effective inter-particle potential. The yield strain exhibits distinct non-monotonic volume fraction dependence for hard spheres below close packing whereas for both soft particles it increases above close packing due to particle softness. Stress overshoots in start-up shear show a common increase with shear rate in all systems. However, the stress overshoots are significantly stronger in star-like micelles due to transient arm entanglements. In relation with that similar stress peaks are detected within the period of the large amplitude oscillatory shear only in star-like micelles. Finally, we discuss the scaling exponents for the G′ and G′′ decrease at large oscillatory strain amplitudes and their relation with steady shear stress.
Nano sized copper particles by electrolytic synthesis and characterizations

This work reports a simple, novel, cost effective and eco-friendly electrolytic synthesis of copper nanoparticles using copper sulphate as metal precursor. The synthesis rate is much faster than other methods and this approach is suitable for large scale production. They are characterized by X-ray diffraction (XRD); scanning electron microscope and Fourier transform-infra red (FT-IR) techniques to analyze size, morphology and functional groups. XRD studies reveal a high degree of crystallinity and monophasic nature of copper nanoparticles. Their particle size is found to be 24 nm and specific surface area (SSA) is 28 m 2 /g. SSA analysis of copper nanoparticles reports that increasing their SSA improves their antibacterial actions. Microbiology essay finds that copper nanoparticles are effective against Escherichia coli and Bacillus megaterium bacteria. SSA of bacteria analysis reveals that it plays a major role while on reactions with antimicrobial agents.
The effect of a thermo-responsive polypeptide-based copolymer on the mineralization of calcium carbonate

CaCO3 crystallization behavior was studied in the presence of a thermo-responsive polypeptide copolymer, poly(N-isopropyl acrylamide)-b-poly(L-glutamic acid) (PNIPAM-b-PLGA). At lower temperatures, the copolymer dissolved well and the unimers mediated the formation of rosette-like calcite crystals through a mesoscale assembly process. At higher temperatures, the copolymer self-assembled into micelles with PNIPAM as the core and PLGA as the shell. The micelles mediated the formation of coral-like aragonite fiber clusters at a high micelle concentration, while fewer aragonite fibers were generated at a low concentration and vaterite crystals were obtained instead of aragonite. The time-resolved experiment revealed that the aragonite fibers were formed through a solution–precursor–solid (SPS) process via a transient polymer-induced liquid-precursor (PILP) phase. The new findings through the experiments can enrich our existing knowledge of biomimetic mineralization and provide useful information for designing functional materials.
Reflection distributions of textured monocrystalline silicon: implications for silicon solar cells

A common misconception is that alkaline textured silicon solar cell surfaces are characterised by features that are pyramidal and bounded by {111} planes. In preference to the typical approach of observing scanning electron microscope images, we analyse reflection distributions from various pyramidal textures and find that {111} faceted pyramids are a poor approximation to the features on such surfaces. We conclude that features are hillocks, with an octagonal base. Furthermore, the characteristic base angle of the texture depends on the etchant and is closer to 50–52° than the commonly accepted value of 54.74°. Analyses of antireflection, light trapping, photogeneration and surface recombination properties of textured surfaces should take this feature morphology into account. The base angle has a strong influence on the hemispherical reflectance of the textured surface, with higher angles resulting in reduced reflectance. The influence of this reflection enhancement upon device performance is smallest when an optimised antireflection coating is applied; compared with an array of {111} faceted pyramids, a hillock morphology with 50° base angle results in a 0.2% reduction in photogenerated current in a typical cell. Additionally, as base angle is reduced, an encapsulant of increasingly higher refractive index is required to drive internal reflection at the air–glass interface of light initially reflected from the cell surface. The development of texturing processes resulting in higher base angles is encouraged. Copyright © 2012 John Wiley & Sons, Ltd.
Anion-exchange membranes in electrochemical energy systems

This article provides an up-to-date perspective on the use of anion-exchange membranes in fuel cells, electrolysers, redox flow batteries, reverse electrodialysis cells, and bioelectrochemical systems (e.g. microbial fuel cells). The aim is to highlight key concepts, misconceptions, the current state-of-the-art, technological and scientific limitations, and the future challenges (research priorities) related to the use of anion-exchange membranes in these energy technologies. All the references that the authors deemed relevant, and were available on the web by the manuscript submission date (30th April 2014), are included.