Miracle-dz/UniFAR-FTUs huggingface dataset:
Multilayer neutron monochromators

Thin-film multilayer monochromators have been fabricated and studied by neutron diffraction. Alternating thin films of two materials, such as Mn and Ge, constitute a one-dimensional crystal owing to the contrast in their scattering amplitude densities. The following are novel features of such a monochromator: (1) large and adjustable d spacing, (2) very high reflectivity, (3) adjustable bandwidth, Δλ/λ. Both kinematical and dynamical theories have been developed to give a proper understanding of the properties of a multilayer. Since a deviation from perfect periodicity can have a substantial effect on diffraction properties of a multilayer, a 'disorder factor' has been introduced in the dynamical theory. Finite resolution of the spectrometer has been taken into consideration when the experimental data are compared with the theoretical expressions. These multilayers can also be used as excellent polarizers and filters for neutrons.
Determination of Tetracyclines Residues in Egg, Milk, and Milk Powder by Online Coupling of A Precolumn Packed with Molecular Imprinted Hybrid Composite Materials to RP-HPLC-UV

A rapid, specific, and sensitive method was developed for determination of tetracyclines (TCs) in egg, milk, and milk powder samples by online molecularly imprinted solid-phase extraction (MISPE) coupled to a reversed-phase high-performance liquid chromatography (HPLC). A molecularly imprinted polymer hybrid composite material (MIP-HCM) was prepared using TC as the template, methacrylic acid as the functional monomer, tetraethoxysilane as inorganic precursor, and methacryloxypropyltrimethoxysilane as the coupling agent. A new technique of online solid-phase extraction (SPE) coupled with HPLC was established. The conditions of online SPE were optimized. Under the optimal conditions, three TCs residues in egg, milk, and milk powder were separated and detected by the proposed method with better clean-up and recoveries. The recoveries of TCs ranged from 85.3% to 98.3%. The limits of detection and quantitation of the proposed method were in the range of 0.76–1.13 µg/kg and 2.53–3.77 µg/kg, respectively. The MIP-HCM was first used as online SPE packing and the hyphenated technique is promising as a general strategy for direct determination of veterinary drug residues in milk and other biological samples.
Development of a General and Practical Iron Nitrate/TEMPO-Catalyzed Aerobic Oxidation of Alcohols to Aldehydes/Ketones: Catalysis with Table Salt

Oxidation of alcohols is a fundamental transformation related to our daily life. Traditional approaches with at least one stoichiometric amount of oxidants are expensive and cause serious environmental burdens. There are many reports on the aerobic oxidation of simple alcohols such as alkyl or phenyl carbinols and allylic alcohols, which used oxygen or air as the environmentally benign oxidant forming water as the only by-product. However, no such protocol has been reported for allenols and propargylic alcohols. Thus, it still highly desirable to develop efficient room temperature oxidations of alcohols with a wide scope including allenols and propargylic alcohols. In this paper, an efficient and clean aerobic oxidation of so far the widest spectrum of alcohols using 1 atm of oxygen or air, producing aldehydes/ketones at room temperature in fairly high isolated yields mostly within a couple of hours is described. It is interesting to observe that the reaction has been efficiently expedited by a catalytic amount of sodium chloride in easily recoverable 1,2-dichloroethane. A mechanism involving NO and NO 2 has been proposed based on the results of the control experiments and GC-MS studies of the in-situ formed gas phase of the reaction mixture.
Effects of donor unit and π‐bridge on photovoltaic properties of D–A copolymers based on benzo[1,2‐b:4,5‐c']‐dithiophene‐4,8‐dione acceptor unit

A series of donor-π-acceptor (D-π-A) conjugated copolymers (PBDT-AT, PDTS-AT, PBDT-TT, and PDTS-TT), based on benzo[1,2-b:4,5-c']dithiophene-4,8-dione (BDD) acceptor unit with benzodithiophene (BDT) or dithienosilole (DTS) as donor unit, alkylthiophene (AT) or thieno[3,2-b]thiophene (TT) as conjugated π-bridge, were designed and synthesized for application as donor materials in polymer solar cells (PSCs). Effects of the donor unit and π-bridge on the optical and electrochemical properties, hole mobilities, and photovoltaic performance of the D-π-A copolymers were investigated. PSCs with the polymers as donor and PC70BM as acceptor exhibit an initial power conversion efficiency (PCE) of 5.46% for PBDT-AT, 2.62% for PDTS-AT, 0.82% for PBDT-TT, and 2.38% for PDTS-TT. After methanol treatment, the PCE was increased up to 5.91%, 3.06%, 1.45%, and 2.45% for PBDT-AT, PDTS-AT, PBDT-TT, and PDTS-TT, respectively, with significantly increased FF. The effects of methanol treatment on the photovoltaic performance of the PSCs can be ascribed to the increased and balanced carrier transport and the formation of better nanoscaled interpenetrating network in the active layer. The results indicate that both donor unit and π-bridge are crucial in designing a D-π-A copolymer for high-performance photovoltaic materials. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1929–1940
Flexibility Analysis in Flowsheet Simulation of Solids Processes

This paper proposes a method for the flexibility analysis in flowsheet simulation of solid processes. It provides the evaluation of a process with varying independent variables in terms of acceptance regarding the process demands. The existence of control variables for the operation of the process is considered as well as processes without this potential. The result is a plain information about the capability of the process to handle varying independent influencing variables. The method gives an approximation of the largest inscribed block-shaped volume within the solution space, spanned by the vector of the independent variables. So that for each variable, a range is given for which an allowed operating point can be achieved. The method is applied to a soil-washing process as an important example in the field of solids processes.
Design of Catalytically Active Cylindrical and Macroporous Gold Microelectrodes

Porous gold structures with a well‐defined pore size and thickness are obtained through electrochemical deposition of gold in a colloidal crystal template synthesized by the Langmuir–Blodgett (LB) technique. Cylindrical gold wires were used as substrates for the LB deposition of successive monolayers of silica particles of various sizes, and the electrodeposition of gold through this inorganic template led to a homogeneous, porous metal structure. These materials were characterized through typical electrochemical experiments and showed high surface‐to‐volume ratios with promising features for their further use in miniaturized electrocatalytic devices.
Photovoltaic Behavior of Nanocrystalline SnS/TiO2

Nanocrystalline tin sulfide (SnS) was prepared by chemical bath deposition, and the photovoltaic behavior of SnS/TiO2 was studied. The X-ray diffraction pattern and transmission electron microscopy revealed an ∼6 nm SnS polycrystalline orthorhombic structure. The SnS film exhibited a band gap of 1.3 eV, and its absorption coefficient was more than 1 × 104 cm−1 in the visible light range. The electrical conductivity activation energy of the SnS film was 0.22 eV, determined when the sample was heated in the temperature range of 111−144 °C. Although the sample was insulating at room temperature, photovoltaic behavior was found in a SnS/TiO2 structure, with an open-circuit voltage (Voc) of 471 mV, a short-circuit current density (Jsc) of 0.3 mA/cm2, and the conversion efficiency (η) of 0.1% under 1 sun illumination. The properties of SnS and the reasons behind the photovoltaic phenomenon of SnS/TiO2 are discussed.
Effect of Transition Metal Complexes on Aryl—Aryl Coupling.

Aryl-aryl coupling is a crucial step in the synthesis of natural biaryls. Ullmann and Bielecki in 1901 discovered the formation of biaryls by the condensation of two molecules of aryl halides in the presence of finely divided copper• In order to avoid the onen very high temperatures required, a number of new methods have been introduced by Semmelhack. In these Ni, Rh and Pd complexes such as Ni(CODh and Ni(PPh3)4 d . h. I 23 use m stoc tometnc amounts rep ace copper · . Thus aryl halides could be coupled in high yields at temperatures as low as 45-50°C. Biaryls can also be prepared by coupling aryl Grignard reagents with aryl halides. The well established Nickel complex that can catalyze this coupling is the Tamao-Kumada catalyst NiCh(PR3h (R = alkyl or aryl)' . Apart from this, a wide range of other Nickel catalysts such as NiCh(dppe), [Ni(enh]Ch, Ni(acac)2 can be used 6 ' 7 .
Biodiesel synthesis from the esterification of free fatty acids and alcohol catalyzed by long-chain Brønsted acid ionic liquid

A long-chain Bronsted acid ionic liquid (IL), 3-(N,N-dimethyldodecylammonium)propanesulfonic acid p-toluenesulfonate ([DDPA][Tos]), was prepared and characterized by FT-IR, 1H NMR, 13C NMR, UV/vis and TGA. The H0 (Hammett function) value of the IL was also determined. The IL as catalyst was applied to the catalytic synthesis of biodiesel from free fatty acids (FFAs). The influencing factors, such as the type and amount of catalyst, reaction time, molar ratio of fatty acid to methanol and reaction temperature, were investigated. The results indicated that the long-chain Bronsted acid IL showed high catalytic activity and fair reusability. Esterification was accomplished under the following optimized conditions: molar ratio of alcohols to FFA at 1.5 : 1, mole fraction of ionic liquid at 10%, 60 °C, and 3 h. The products could be separated from the catalyst system by liquid–liquid biphase separation at room temperature with good yields of 92.5% to 96.5%. The catalyst could be reused nine times after the removal of water and alcohol. Therefore, the long-chain Bronsted acid IL has good potential for the synthesis of biodiesel from low-cost feedstocks such as waste oil and woody plant oils.
CHARACTERIZATION OF PROTON CONDUCTING PVDF-HFP/PEMA BLEND BASED SOLID ELECTROLYTES

Proton conducting poly(vinylidene fluoride-cohexafluoropropylene)/polyethyl methacrylate (PVDF-HFP/PEMA) blend based electrolytes with different compositions of NH4CF3SO3 salt have been prepared and characterized. XRD and SEM studies show that the addition of NH4CF3SO3 helps to generate more amorphous region in the semicystalline PVDFHFP/PEMA system. The conductivity of the blend based electrolyte system increases with increasing content of NH4CF3SO3. The system containing 40 wt % of salt exhibits the highest room temperature conductivity of 6.90 × 10-4 S cm-1. The temperature dependence of ionic conductivity of the system follows an Arrhenius behavior. The frequency dependence of conductivity of the system obeys the universal power law, σ(ω) Aω∝n. The pre-exponent, n is found to decrease with increasing temperature suggesting that the Correlated Barrier Hopping model can be used to explain the conduction mechanism in the system. http://journal.masshp. net/wpcontent/uploads/Journal/2009/Jilid%201/Siti%20Rudhziah%2073-80.pdf
In situ spectroscopic ellipsometry as a versatile tool for studying atomic layer deposition

In this paper recent work on the application of in situ spectroscopic ellipsometry (SE) during thin film synthesis by atomic layer deposition (ALD) is reviewed. In particular, the versatility of this all-optical diagnostic is demonstrated by results obtained on Al2O3, HfO2, Er2O3, TiO2, Ta2O5, TiN and TaNx films with thicknesses ranging from 0.1 to 100 nm. By acquiring SE data in between the ALD cycles and by analysing the film thickness and the energy dispersion of the optical constants of the films, the layer-by-layer growth and material properties of the films can be studied in detail. The growth rate per cycle and the ALD saturation curves can be determined directly by monitoring the film thickness as a function of the number of cycles, while also the nucleation behaviour of the films on various substrates and submonolayer surface changes during the ALD half-cycles can be probed. The energy dispersion relation provides information on the optical properties, the crystalline phase and the material composition of the films. For metallic films, electrical properties can be calculated from the Drude absorption yielding insight into the electrical resistivity and electron scattering effects in ultrathin films.
A Monte Carlo study of water at an uncharged clay surface

Monte Carlo simulations have been used to study water confined between uncharged clay sheets. Low-energy sites for water at a talc surface were identified. The water molecules adsorbed onto these sites, which lie above the clay's hydroxyl group, are able to form strong hydrogen bonds with waters in the next hydration layer and so perturb the structure of this layer. No restructuring of the hydrogen bond network was apparent beyond this second layer.
A facile one-step way to anchor noble metal (Au, Ag, Pd) nanoparticles on a reduced graphene oxide mat with catalytic activity for selective reduction of nitroaromatic compounds

A facile, one-step clean strategy has been utilized for anchoring noble metal (Au, Ag, Pd) nanoparticles onto the flat surface of two-dimensional (2D) graphene oxide (GO) nanosheets. Without using any additional reductants, surfactants or protecting ligands, the deposition of metallic noble metal (Au, Ag, Pd) nanoparticles on the partially reduced graphene oxide (PRGO) mat has been realized by a simple redox reaction between the noble metal precursors and GO in an aqueous solution. The main size distributions of the Au, Ag and Pd particles are centered on 1–20 nm, 3–10 nm and 0.5–3 nm, respectively. The as-obtained Au, Ag and Pd–PRGO nanocomposites display superb catalytic activities for the selective reduction of nitroaromatic compounds into the corresponding amino compounds under ambient conditions. The rates of reduction follow the sequence, Pd–PRGO > Ag–PRGO > Au–PRGO, suggesting that the smallest noble metal particles size affords the highest catalytic activity. In addition, considering that the Au, Ag and Pd–PRGO nanocomposites still hold the abundant functional groups of the original GO, these noble metal–PRGO composites maintain the excellent hydrophilic nature of GO, which provides a flexible platform for the further fabrication of PRGO–metal-based multicomponent functional materials by a wet-chemistry approach.
Determination of 11 Ginsenosides in Black Ginseng Developed from Panax ginseng by High Performance Liquid Chromatography

A high performance liquid chromatography (HPLC) method has been developed for determination of 11 ginsenosides in black ginseng (BG, white ginseng that is subjected to 9 cycles of 95℃ for 3 hr). After eluted by gradient elution of water-acetonitrile without buffer in 70 min, 11 ginsenosides in BG were identified. The proposed method provided good linearity (R²＞0.9995), accuracy (92.2-106.6%), and intra- and interday precision (RSD＜2.6%). In addition, ginsenosides compositions in white, red, and black ginsengs were investigated using this method, respectively. Interestingly, in BG, the content of ginsenoside Rg3 which does not existed in white ginseng was 7.51 ㎎/g, approximately 20 times than that in red ginseng.
Speciation of non-covalent nickel species in plant tissue extracts by electrospray Q-TOFMS/MS after their isolation by 2D size exclusion-hydrophilic interaction LC (SEC-HILIC) monitored by ICP-MS

An original approach based on successive size-exclusion and hydrophilic interaction HPLC (HILIC) was developed to purify traces of Ni species from a plant aqueous extract. The degree of purity achieved was for the first time sufficient for the identification, in a natural sample, of a number of non-covalent metal complexes by electrospray Q-TOFMS/MS. Nickel complexes with malate, citrate, histidine, EDTA and nicotianamine (NA) were identified in the roots, xylem, shoots and their protoplasts of a metal hyperaccumulator plant Thlaspi caerulescens. The quantitative recovery of the most stable of these complexes (with EDTA and NA) allowed their quantitative determination by SEC-ICP-MS.
NUTRIENT UPTAKE, PHYSIOLOGICAL RESPONSES, AND YIELD ATTRIBUTES OF WHEAT (TRITICUM AESTIVUM L.) EXPOSED TO EARLY AND LATE DROUGHT STRESS

The response of different wheat cultivars to drought imposed after three and six weeks of seedling emergence was evaluated in the wire house. The seeds of recommended local wheat cultivars were sown in plastic pots. The drought stress decreased the water relation, nutrient uptake and grain yield of all the wheat cultivars. The early drought stress significantly reduced the nitrogen (N) uptake by 38% while late drought stress decreased nitrogen uptake by 46%. The phosphorus (P) and potassium (K) uptake were decreased by 49% and 37% under early drought stress, respectively while their uptake was decreased by 51% each under late drought stress. Grain yield was reduced by 24% under early drought stress while it was reduced by 60% under late drought stress. Water deficit at early growth stages reduced grain weight by 10% while it was reduced by 35% under water deficit at later stages of growth.
Role of magnetic Fe3O4 graphene oxide in chemiluminescent aptasensors capable of sensing tumor markers in human serum

Using π–π stacking interaction between magnetic Fe3O4 graphene oxide nanoparticles and impurities (e.g., biomolecules, free prostate specific antigen (PSA) aptamer-conjugated TEX615 that does not bind with PSA) in human serum, a rapid aptasensor with 1,1′-oxalyldiimidazole chemiluminescence (ODI-CL) detection was developed for the quantification of PSA, a tumor marker. The complexes, PSA bound with PSA aptamer-conjugated TEX615, were formed in human serum while the mixture (1 : 1 volume ratio) of PSA in 25% human serum diluted in Tris–HCl buffer (pH 7.5) and PSA aptamer-conjugated TEX615 in Tris–HCl buffer was incubated for 30 minutes. After the incubation, the impurities capable of reducing the efficiency of the aptasensor were removed using magnetic Fe3O4 graphene oxide nanoparticles. With the addition of ODI CL reagents (e.g., ODI, H2O2), finally, PSA in each sample was quantified within 1 second. The sensitivity of the aptasensor with good accuracy, precision, and recovery was as good as those of enzyme immunoassays with absorbance and chemiluminescence detections operated using time-consuming procedures such as multiple-time incubation and washing and expensive and intractable antibodies.
Mineral Content and Root Respiration of In Vitro Grown Kiwifruit Plantlets Treated with Two Humic Fractions

ABSTRACT In vitro grown kiwifruit (Actinidia deliciosa, Liang and Ferguson) plantlets were treated with two humic fractions distinguished by two different relative molecular mass and characterized through their elemental composition and 13Carbon (C) nuclear magnetic resonance. The effects exerted on plant growth, root morphology, and nutrition were evidenced by means of leaves and roots mineral content, root respiration, and nitrate reductase activity. The two humic substances differentially influenced the studied parameters. The lower molecular fraction humic substance, endowed with a higher content of phenolic and carboxylic groups, caused an enhanced content of micro- and macro-elements, together with a higher root respiration at lower concentrations (0.5–1 mg C L− 1). The high molecular fraction humic substance, needed higher concentrations (> 5 mg C L− 1) in order to achieve similar effects. This fraction also caused major changes on root morphology. The ability to improve micronutrient assimilation, in particular iron, confirmed the agronomic importance of humic substances on soil fertility.
Copper and Nickel Recovery from Electroplating Sludge by the Process of Acid-leaching and Electro-depositing

In this work, we developed a method which combined the processes of acid-leaching, ammonium jarosite precipitating and electro-depositing to recover copper and nickel from electroplating sludge. Residual sludge from an electroplating plant located in Qingdao was used for acid-leaching, and more than 95% of copper, nickel, zinc, chromium and iron were extracted from the sludge. After acid-leaching, the extracted solution was put into an electrolytic cell for copper recovery by electro-depositing process, and about 95% of copper was recovered under the optimized operation parameters such as cell voltage, pH and electrode material. After copper recovery, the extracted solution was treated with ammonium jarosite precipitating process. About 99% of chromium and iron could be deposited as chromium ferrite in this process. Finally, the left solution was treated with electro-depositing process again for nickel recovery, and about 57% of nickel could be recovered in this process under the condition of pH 5.5 and voltage 5.5V.
Process–quality optimization of the vacuum freeze-drying of apple slices by the response surface method

Summary Working pressure (P) and heating plate temperature (T) were considered to be the most important factors affecting the kinetics of the freeze-drying operation for apple slices as well as the criteria of final product quality (appearance/shape, colour, texture, rehydration ratio). Freeze-drying experiments involving a thick layer of slices under different processing conditions were designed according to a central composite rotatable system with two factors (P, T). Results were analysed by response surface methodology (RSM). By superimposing all quality criteria contour plots, the optimum levels of processing conditions yielding the best quality freeze-dried apple slices were determined to be an operating pressure of 50 Pa, and a heating plate temperature of 55 °C. For a product loading of 17 kg m−2, the freeze-drying time ranged from 48 to 50 h. The experimental values of the freeze-drying time, appearance and colour of freeze-dried apple slices obtained with these optimal conditions were very similar to those predicted by the corresponding second order polynomial model. The rehydration ratio of freeze-dried apples was about 0.55 g g−1 of water removed and the texture loss of rehydrated apples was estimated to be more than 85%.
An Annotated Bibliography of Recent Elasticity and Flexibility Estimates for Meat and Livestock

Supply and demand models are an important part of economic theory and these models underlie much of the applied work done by economists. To answer questions about the effects of specific shocks to a sector, economists need estimates of the relevant supply and demand elasticities. To support the applied analysis of the Animal Products Branch, this bibliography of recent empirical estimates of U.S. demand and supply elasticities for livestock, meat, and poultry was compiled. Each reference is followed by a brief discussion of the techniques and data used and (usually) tables showing the estimated elasticities.