Miracle-dz/UniFAR-FTUs huggingface dataset:
Uranyl ion‐sensitized polymerization of acrylamide and methacrylamide in aqueous solution

The kinetics of polymerization of the vinyl monomers, acrylamide and methacrylamide, photosensitized by uranyl ions in homogeneous aqueous acid medium was studied systematically. Monochromatic radiation of wavelengths 365, 405, and 436 mμ was used for irradiation. Uranyl perchlorate in aqueous perchloric acid (pH=0-2) was used as the sensitizer to ensure that only uncomplexed UO22+ ions existed in the solution. Polymerization was found to proceed without any induction period, the steady state being attained in about 10-20 min., and was followed by the measurement of the rate of monomer disappearance by bromine addition method. The chain lengths of the polymers were determined by viscometry. It was observed that there was no change in the initiator concentration, [UO22+], during polymerization. The dependence of the rate of polymerization on variables like light intensity, light absorption fraction by the active species, wavelength, monomer concentration, hydrogen ion concentration, temperature, nature of the acid used (HClO4 and H2SO4), viscosity of the medium etc., were studied. A kinetic reaction scheme is proposed and discussed in the light of the experimental results. Certain rate parameters were calculated. The mechanism of photosensitization by uranyl ions with specific reference to primary photochemical act, initiation of polymerization etc., are discussed.
Application of 7-endo, 8-endo and 9-endo radical cyclisations to the synthesis of conformationally constrained amino acids and comparison with the corresponding Heck reactions

Radical cyclisation of substrates 1a–c proceeds smoothly to give seven-, eight- and nine-membered rings 3a–c in 73, 71 and 52% yield respectively; comparison of these results with those obtained using the intramolecular Heck reactions suggests that the two cyclisation methods provide complementary approaches to medium-sized rings.
PEDOT:PSS Films with Greatly Enhanced Conductivity via Nitric Acid Treatment at Room Temperature and Their Application as Pt/TCO‐Free Counter Electrodes in Dye‐Sensitized Solar Cells

A room‐temperature HNO3 treatment method is developed that significantly enhances the conductivity of a poly(3,4‐ethylenedioxythiophene):poly(4‐styrenesulfonate) (PEDOT:PSS) film, which is one of the most promising transparent conducting materials. The PEDOT:PSS film treated with HNO3 exhibits a conductivity as high as 4100 S cm−1, which is the highest value among reported conductivities achieved by treatments at room temperature. The mechanism of this conductivity enhancement is elucidated by means of electrical, optical, structural, and compositional characterizations of the PEDOT:PSS films. The HNO3 treatment induces phase separation and crystallization in the (100) and (200) directions of PEDOT:PSS through selective removal of the PSS domains. This rearrangement significantly increases the conductivity through an enhancement of the inter‐chain interaction between the conducting polymers. Dye‐sensitized solar cells (DSSCs) that adopt these films as counter electrodes are developed as an example of practical applications. Using the HNO3‐treated PEDOT:PSS films, a power‐conversion efficiency of 8.59% is achieved for Pt/fluorine‐doped tin oxide (FTO)‐free DSSCs. This study demonstrates that a facile HNO3 treatment at room temperature is one of the most promising methods for obtaining highly conductive and transparent PEDOT:PSS films, and it facilitates the commercial use of PEDOT:PSS in next‐generation transparent electrodes.
Chemical Composition of Essential Oils from Perilla setoyensis, A New Species of Wild Perilla in Japan

Abstract The essential oil of Perilla setoyensis G. Honda, a newly discovered wild perilla in Japan, was examined by GC and GC/MS. The principal volatile constituent of the leaves was revealed to be a novel monoterpene, shisofuran, which was fully characterized by spectroscopic means. Nonetheless, shisofuran (18.3–196%) was labile and decomposed during steam distillation, leaving 1-octen-3-ol (16.2–21.8%) and β-caryophyllene (18.3–19.6%) as the major constituents of the oil.
Electrical Conductivity and Lattice Defects in Nanocrystalline Cerium Oxide Thin Films

The results of the electrical conductivity and Raman scattering measurements of CeO2 thin films obtained by a polymeric precursor spin-coating technique are presented. The electrical conductivity has been studied as a function of temperature and oxygen activity and correlated with the grain size. When compared with microcrystalline samples, nanocrystalline materials show enhanced electronic conductivity. The transition from extrinsic to intrinsic type of conductivity has been observed as the grain size decreases to <100 nm, which appears to be related to a decrease in the enthalpy of oxygen vacancy formation in CeO2. Raman spectroscopy has been used to analyze the crystalline quality as a function of grain size. A direct comparison has been made between the defect concentration calculated from coherence length and nonstoichiometry determined from electrical measurements.
The properties, genesis and significance of a man-made iron pan podzol near Castletownbere, Ireland

Summary Beneath a layer of artificially deposited peat debris, an eluvial E horizon and thin iron pan (Bsm) has developed in the upper part of the Ap horizon of a brown podzolic soil (Haplorthod) near Castletownbere, Ireland. The thickness of the E horizon and the depth of the pan are directly related to the thickness of the layer of peat debris. The original soil (Haplorthod) was strongly podzolized with a significant accumulation of organic carbon, iron and aluminium in the spodic Bs. The iron pan of the upper sequum, on the other hand, is rich in iron. This iron pan seems to have developed as a result of reduction of iron in the E horizon, transport of divalent Fe2+ cations and precipitation in the Bsm as Fe2(OH)3, after the peat layer was deposited. We conclude that podzolization and iron pan development were fundamentally different processes. The study suggests a fundamental change in the iron pan-blanket peat development sequence previously postulated by palaeoenvironmentalists in Ireland.
Platelet-rich plasma in facial rejuvenation

Objective This study aimed at evaluating the effect of using a combination of platelet-rich plasma (PRP) and hyaluronic acid (HA) 3.5% using microneedling in facial skin rejuvenation and to estimate the visible skin improvement and patient satisfaction. Background PRP has attracted attention in the field of dermatology, specifically in the aesthetic field for skin rejuvenation. HA is involved in maintaining skin hydration. PRP along with HA offers a good combination for skin rejuvenation via microneedling for augmentation of collagen content, for increasing moisture, and for offering a rich source of growth factors. Materials and methods A total of 30 participants were enrolled in study and received facial treatments with PRP and HA through microneedling using dermapen every 2 weeks, and the results were evaluated through the assumed visual assessment scale. Results The results yielded statistically significant improvement concerning skin texture, dullness, acne, acne scars, wrinkles, wide pores, pallor, and firmness compared with baseline. Moreover, enrolled participants showed marked satisfaction with the results with minimal adverse effects. Conclusion PRP along with HA represents a potentially effective and safe material for skin rejuvenation through microneedling using dermapen.
Synthesis and Characterization of Mononuclear Amidogold(III) Complexes − Crystal Structure of [Au(N2C10H7(CMe2C6H4)‐6](NHC6H3Me2‐2,6)][PF6] − Oxidation of 4‐Methylaniline to Azotoluene

Mononuclear amidogold(III) complexes [Au(C,N,N)(NRR′)][PF 6 ] [C,N,N = N 2 C 10 H 7 (Cme 2 C 6 H 4 )-6, where N 2 C 10 H 8 = 2,2′-bipy; R = H, R′ = p -tolyl ( 5 ), o -xylyl ( 6 ), isobutyl ( 7 ), sec -butyl ( 8 ), R = R′ = Et ( 9 )], [Au(C,N)(AcO)(NHC 6 H 4 NO 2 -4)] ( 10 ) [C,N = NC 5 H 4 (CH 2 C 6 H 4 )-2, where NC 5 H 5 = py] and [Au(N,N)(NHC 6 H 4 NO 2 -4) 2 ][PF 6 ] ( 11 ) (N,N = 2,2′-bipy), have been synthesized in fairly good yields by reaction of the hydroxo, methoxo, or acetato complexes 1−4 {[Au(C,N,N)(OR)][PF 6 ] [R = H ( 1 ), Me ( 2 )], [Au(C,N)(AcO) 2 ] ( 3 ), [Au(N,N)(OH) 2 ][PF 6 ] ( 4 )} with amines. The structure of [Au(C,N,N)(NHC 6 H 3 Me 2 -2,6)][PF 6 ] ( 6 ) has been determined by X-ray diffraction. Reaction of the hydroxo complex 4 with NH 2 C 6 H 4 Me-4 gives metallic gold, the protonated ligand [N,NH][PF 6 ] and organic products, the main one being azotoluene.
Calculation of an OMIT map

A space-group-general computer program to compute an OMIT map using fast Fourier transforms is presented. In this procedure an asymmetric unit of the unit cell is divided into several boxes. For each box a set of phases is calculated by the inverse Fourier transforms of the existing electron density distribution which has been modified so that the electron density values in and around that box is a constant. An OMIT map is then calculated for each box by the Fourier transforms of the observed amplitudes with these phases. The computer program may be used to reduce bias in electron density maps during model building and refinement of macromolecules. The procedure was used to detect error in the atomic model of a derivative of ribonuclease (personal communication by J. Nachman, National Cancer Institute, Frederick, Maryland, USA).
The Effects of UV Irradiation and Incubation Time on in vitro Phenolic Compound Production in 'Karaerik' Grape Cultivar

In this study, the effect of Ultraviolet (UV) irradiation on induction of individual and total phenolics production on callus cultures of ‘Karaerik’ grape cultivar was investigated. Callus tissues were obtained from the leaves of the cuttings grown in in vitro plants. As a culture medium, Gamborg B-5 was utilized with 0.1 mg L-1 NAA (Naphthaleneacetic acid) and 0.2 mg L-1 Kin (Kinetin). Callus tissues were sub-cultured twice with 21 days intervals. After the second subculture, 12-day-old callus tissues were exposed to 254 nm UV-C light at 10 cm distance from the source for 10 and 15 min by opening covers of the petri dishes in sterile cabin. After the treatment, callus tissues were incubated under dark conditions. Phenolic compounds were measured at 24th, 48th and 72nd hours. Individual phenolic compounds were analyzed by HPLC (High Pressure Liquid Chromatography) and total phenolic compounds were measured by spectrophotometer. As a result of the study, it was found that UV irradiation was effective for induction the production of phenolic compounds in the callus tissues of ‘Karaerik’ grape cultivar and this effect was closely related to the application time. Research Article Article History Received : 04.04. 2020 Accepted : 04.06. 2020
A novel physical model for partial discharge in narrow channels

In order to reveal the mechanism of partial discharge (PD) in electrical trees, an artificial single channel is studied as model for tree channels. In a long-narrow channel, the behaviour of PD is similar to that in an actual tree. When the length of the channel is decreased, the /spl phi/-q-n pattern of PD in the channel changes from wing to turtle or rabbit like, and the range of light emission in the channel increases when the applied voltage is increased. Considering the influence of a PD on the total field distribution and thus on a later PD, a physical model is put forward to describe the PD behaviour. It is assumed that PD is induced by the high field at the needle tip, then propagates along the channel, and stops propagating when the field in the channel becomes lower than a critical value due to field divergence. Mathematical analysis on an ideal needle-plane electrode system clearly explains the physical meaning of the model. And the computer simulation by using the superposition method agrees with the experimental results very well. This model is also valid to describe the behaviour of PD in electrical trees.
Investment Activity in Russia’s Regions

Any economic system, no matter what its internal configuration is or what kind of external impact it is exposed to, needs investment for rational development. The volume and structure of investment, as well as the efficiency of the way it is used, may influence the development of both the country as a whole and its specific regions in particular. The management of economic systems will not be thoroughgoing without the management of investment. Economic reproduction is characterized based on the rate of investment activity. Some discouraging figures posted in this context in the Russian Federation (RF), namely 8.4%, which is the share of organizations engaged in technological, organizational, and marketing innovation (Rosstat, 2017), are a clear testimony to the topicalness of the issue in question. This paper presents an assessment of investment activity in Russia, as well as across its regions. The authors have developed a methodology for forecasting the investment-based development of regions based on the calculation of the share of investment in the gross regional product (GRP) and the use of an integral indicator which factors in the effect of various factors on investment activity in a region. A separate stage in these assessments is the calculation of an integral coefficient which reflects the impact of factors impeding investment activity. The study’s primary purpose is to assess investment activity in Russia’s regions and forecast the share of investment in the GRP of the RF constituent entities based on a multi-factor model.
Pre-proof Why trials lose participants : a multi-trial investigation of participants ’ perspectives using the theoretical domains framework

Please cite this article as: Rumana Newlands , Eilidh Duncan , Justin Presseau , Shaun Treweek , Louisa Lawrie , Peter Bower , Jim Elliott , Jill Francis , Graeme MacLennan , Margaret Ogden , Mary Wells , Miles D. Witham , Bridget Young , Katie Gillies , Why trials lose participants: a multitrial investigation of participants’ perspectives using the theoretical domains framework, Journal of Clinical Epidemiology (2021), doi: https://doi.org/10.1016/j.jclinepi. 2021.03. 007
The ETCH Mechanism for Al2O3 in Fluorine and Chlorine Based RF Dry Etch Plasmas

The etch behaviour of Al2O3 was studied in Ar, CHF3/Ar, CF4/O2 and Cl2 low pressure RIE plasmas.The influence of dc self-bias voltage, wafer temperature, gas flow and pressure on the Al2O3 etch behaviour was investigated.This was compared with the etch behaviour of SiO2, Mo, Au and Si under the same conditions.It was found that even though aluminum does not form volatile fluorides addition of CHF3 to an Ar plasma resulted in a ninefold increase in the A12O3 etch rate.This compares to a fivefold increase in the SiO2 etch rate and a 20% decrease in Au etch rate. An A12O3 etch mechanism for fluorine based plasmas is proposed, comprising of the formation of AlFx and its subsequent removal under influence of high energy ion bombardment.The latter appears to be the rate limiting step.
Simple Ways to Characterize Non-isothermal Crystallization of Homogeneous Poly(ethylene-1-co-octene) Copolymer

Abstract Non-isothermal crystallization of homogeneous poly(ethylene-co-1-octene) copolymers with different octene contents was studied using power-compensating differential scanning calorimetry as functions of cooling rate and comonomer content. With increasing cooling rate, the crystallization temperature decreases for all polymers. A single crystallization peak was observed for polyethylene, while multiple crystallization peaks were observed for copolymers. The non-isothermal crystallization rate of these copolymers was estimated by continuous cooling transformation (CCT) curves, crystallization rate coefficient (CRC), and crystallization rate parameter (CRP). With increasing comonomer content, the CRC value decreases and CCT curves shift to longer time under the same degree of supercooling, indicating the crystallization rate decreases. However, the CRP value can't successfully estimate the crystallization rate of these copolymers.
Effect of Different Chemical Modification Systems on Thermal and Electrical Conductivity of Functionalized Multiwall Carbon Nanotube/Epoxy Nanocomposites

The use of polymeric materials in some applications is inhibited due to their low thermal conductivity. In this study epoxy nanocomposites of three differently modified carbon nanotubes were prepared and their thermal, electrical and mechanical properties were investigated. Acidic oxidation, amine grafting and Friedel-Crafts reactions were employed to prepare modified carbon nanotubes. It was found that nanocomposites obtained by Friedel-Crafts acylation reaction have superior thermal and electrical conductivity. Therefore, the addition of a very low amount of benzene tricarboxylic acid (BTC) nanotubes can result in a considerable improvement in the thermal and electrical conductivity of the resulting nanocomposite.
Oxygen Vacancy Ordering and the Conductivity Maximum in Y2O3-Doped CeO2

The defect structure and ionic diffusion processes within the anion-deficient, fluorite structured system Ce1–xYxO2–x/2 have been investigated at high temperatures (873 K–1073 K) as a function of dopant concentration, x, using a combination of neutron diffraction studies, impedance spectroscopy measurements, and molecular dynamics (MD) simulations using interionic potentials developed from ab initio calculations. Particular attention is paid to the short-range ion–ion correlations, with no strong evidence that the anion vacancies prefer, at high temperature, to reside in the vicinity of either cationic species. However, the vacancy–vacancy interactions play a more important role, with preferential ordering of vacancy pairs along the ⟨111⟩ directions, driven by their strong repulsion at closer distances, becoming dominant at high values of x. This effect explains the presence of a maximum in the ionic conductivity in the intermediate temperature range as a function of increasing x. The wider implications o.
Soil Acidification from Long‐Term Use of Anhydrous Ammonia and Urea

Acidity generated by N fertilizers depends on factors such as the composition of the fertilizer, climatic and soil conditions, and the crops grown. Our objective was to quantify the acidifying effects of urea and anhydrous NH 3 when used as fertilizers for cereal production in Saskatchewan, Canada. The fertilizers were injected annually (at 10-cm depth) into a medium-textured, moderately acid (pH 5.5) Typic Haploboroll, at rates of 0, 45, 90, and 180 kg N ha -1 for 9 yr. Soil acidity increased as N application rate increased, with anhydrous NH 3 causing greater acidification than urea. Although pH values as low as 4.3 were recorded in soil treated with anhydrous NH 3 , KCl-exchangeable acidity remained low. The major effect of acidification was a depletion of exchangeable Ca and Mg. The solubility of Mn (but not Al) increased substantially as pH decreased, with solution concentrations of almost 30 mg Mn L -1 being recorded 6 d after injection of NH 3 . Acidity generated by anhydrous NH 3 compared well with values predicted assuming that all of the applied NH 3 was oxidized to NO - 3 (with the production of 1 mol H + mol -1 of N) and that these protons were partly neutralized by OH - released when NO - 3 was taken up and assimilated by plants. Acidification due to export of bases in grain was insignificant because wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) remove only a slight excess of cations over anions. Urea failed to realize its full acidification potential because of an apparent loss of urea-N from the soil by NH 3 volatilization.
Allosteric Coextraction of Sodium and Metal Ions with Calix[4]Arene Derivatives 3. Effect of Propyl Groups on Size-Discrimination for the Second Coextracted Ion

A calix[4]arene derivative containing two propyl groups and two acetic acids at each distal position has been synthesized and investigated for alkali metal extraction in individual and competitive systems. In an individual system, lithium ion simultaneously loads on a single molecule of the extraction reagent up to 200%, while sodium and potassium ions load up to 150% and 100%, respectively. In a competitive system, sodium as the first ion and lithium as the second among three ions each load up to 100%. The peak shift of the extraction reagent by using 1H-NMR spectroscopy was investigated to elucidate the extraction mechanism of alkali metals in individual and competitive systems. The complex structures and extraction reactions for three ions are proposed from the results obtained. Size discrimination is observed not only for extraction of the first ion, but also the second ion as facilitated by an allosteric effect. Coordinatively-inert propyl groups provide a narrow coordination space for the discrimination of the second coextracted ion.
Fill factor analysis of solar cells' current–voltage curves

After completion of the solar cell manufacturing process the current–density versus voltage curves (J(U) curves) are measured to determine the solar cell's efficiency and the mechanisms limiting the efficiency. An accurate and robust analysis of the measured curves is essential. In this work it is shown that fitting the two‐diode model is inappropriate to quantify recombination in the space charge region and ohmic losses due to series resistance. Three fill factors, namely the fill factor of the illuminated J(U) curve, the pseudo fill factor of the sunsVoc curve and the ideal fill factor of the single diode model, are the base of a quick loss analysis that is evaluated in the present paper. It is shown that for an accurate analysis the distributed character of the series resistance and the network character of the solar cell cannot be neglected. An advanced current–voltage curve analysis including fill factors and fit is presented. Copyright © 2010 John Wiley & Sons, Ltd.
Chemical Properties of 2‐Bromodecanoic Acid

Abstract Some chemical equilibrium constants for 2‐bromodecanoic acid were investigated. The dimerization constant of 2‐bromodecanoic acid, k2 =278 M−1, in tert‐butylbenzene was first derived from IR spectroscopy measurements. Secondly, the distribution coefficient, k d =799, was found by combining the value of k2 with distribution data obtained from solvent extraction experiments evaluated with the aid of neutron activation analysis. Finally the dissociation constant, k a =3.18 *10−3 M, was estimated from two‐phase titrations. A theoretical calculation was made based on the obtained constants and this calculation was validated by a second solvent extraction experiment that gave a good correspondence between calculated and experimental values.
Building Life Skills and Interest in STEM Through Rural 4-H Robotics Camps

Many rural communities are looking for inexpensive and innovative ways to engage youth in science, technology, engineering, and mathematics (STEM). University Extension 4-H programs offer a unique platform to increase rural youth exposure to STEM and build important life skills. This study employed a mixed-methods approach to examine ways in which 47 youth in five rural robotics day camps grew in targeted 4-H life skills and enthusiasm for science. Campers perceived growth in their decision making and ability to use limited resources during these short day camps. Furthermore, participant observations and responses to open-ended prompts in their “science notebooks” provided insight as to potential mechanisms for this growth and behavioral patterns that enhanced the camper experience. We argue that increasing STEM knowledge and skills alone is not sufficient and that future STEM-focused programs should also target life skills such as decision making, teamwork, and communication.