Miracle-dz/UniFAR-FTUs huggingface dataset:
Synthesis and properties of photochromic cholesteric liquid crystalline polysiloxane containing chiral mesogens and azobenzene photochromic groups

A series of novel thermotropic side-chain liquid crystalline polymers(P 0 -P 12 ) were synthesized by grafting copolymerization of mesogenic monomer cholesteryl undecylenate (M1) and photochromic monomer 4-allyoxy-4'-nitroazobenzene (M2) on polymethylhydrosiloxane. The chemical structures of polymers were characterized by infrared (IR) and ultraviolet (UV) spectroscopy. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to measure the thermal properties of those polymers, and the mesogenic properties were characterized by polarized optical micrograph, DSC, wide-angle X-ray diffraction and small-angle X-ray scattering. The glass transition temperatures (T g s) of the polymers increased from P 0 to P 4 and decreased from P 5 to P 12 . The clearing point temperatures (T i s) of the polymers P 1 -P 12 were lower than that of P o , but increased from P 1 to P 4 and decreased from P 5 to P 12 . They showed thermotropic liquid crystalline properties in a broad mesogenic region at temperatures >100°C. The polymers P 0 -P 8 exhibited a cholesteric mesophase with oily streaks and lined texture, and polymers P 9 -P 12 showed a chiral smectic mesogenic phase with a layered texture. All of the polymers were thermally stable to 320°C. The UV-induced trans-cis photoisomerization was investigated for the azo monomer and polymers P 8 and P 12 . The solution of the azo monomer and liquid crystalline polymers P 8 and P 12 can undergo photoisomerization, and the environments of the azo group were responsible for the aforementioned photochemical process.
Polynuclear Metal Complexes Obtained from the Task-Specific Ionic Liquid Betainium Bistriflimide

The task-specific ionic liquid betainium bis(trifluoromethylsulfonyl)imide, [Hbet][Tf2N], was used to dissolve metal oxides and hydroxides. The crystal structures of the resulting metal betaine bistriflimide complexes exhibit a rich structural variety. A trimeric structure was found for the cobalt(II) compound, [Co3(bet)8(Hbet)2(H2O)2][Tf2N]9[Hbet], a tetrameric structure for the manganese(II) and zinc(II) compound, [Mn4(bet)10(H2O)4][Tf2N]8 and [Zn4(bet)10(H2O)2][Tf2N]8, respectively, a pentameric structure for the nickel(II) compound, [Ni5(bet)12(H2O)6][Tf2N]10, an oxo-hydroxo-cluster formation for the lead(II) compound, [(Pb4O)Pb(OH)(bet)8(Tf2N)3][Tf2N]4·MeOH, and a polymeric structure for the silver(I) compound, [Ag2(bet)2(Tf2N)Ag2(bet)2][Tf2N]3. The zwitterionic nature of the betaine ligand and the weakly coordinating ability of the bis(trifluoromethylsulfonyl)imide [Tf2N]− anion facilitates the incorporation of metal ions into oligonuclear and polynuclear metal complexes.
DNA: a novel, green, natural flame retardant and suppressant for cotton

For the first time, deoxyribonucleic acid (DNA) from herring sperm has been employed as a novel flame retardant system for enhancing the thermal stability and flame retardant properties of cotton fabrics. Indeed, DNA could be considered an intrinsically intumescent flame retardant as it contains the three main components that are usually present in an intumescent formulation, namely: the phosphate groups, able to produce phosphoric acid, the deoxyribose units acting as a carbon source and blowing agents (upon heating a (poly)saccharide dehydrates forming char and releasing water) and the nitrogen-containing bases (guanine, adenine, thymine, and cytosine) that may release ammonia. The flammability tests in horizontal configuration have clearly shown that after two applications of a methane flame for 3 s, the DNA-treated cotton fabrics do not burn at all. Furthermore, when exposed to an irradiative heat flux of 35 kW m−2, no ignition has been observed. Finally, an LOI value of 28% has been achieved for the treated fabrics as opposed to 18% of the untreated fabric.
Liquid Structure and Dynamics of Aqueous Isopropanol over γ-Alumina

The liquid structures of thin films of aqueous solutions of 0, 7, 19, 50, and 100 mol % isopropanol above O/Al-terminated γ-alumina ⟨001⟩ surfaces have been investigated by means of classical molecular dynamics simulations. The structuring effect of the oxide on the liquid mixtures is strong and heavily dependent on the local structure of the oxide. Two distinct regions are found on the oxide surface characterized by the degree of coordination of Al atoms. Above octahedral Al atoms, water and isopropanol molecules adsorb via the oxygen atoms to maximize the electrostatic interaction, whereas above tetrahedral Al sites the solvent molecules adsorb via hydrogen atoms with the oxygen atoms away from the surface. More mobility is found in the second layer compared with the first; however, its structure is still influenced significantly by the orientation of molecules in the first adsorbed layer. Qualitatively, the displacement of water from the surface by the adsorption of isopropanol occurs with 2.6 water mo.
Structural and Electrical Characterization of ZnO Films Grown by Spray Pyrolysis and Their Application in Thin‐Film Transistors

The role of the substrate temperature on the structural, optical, and electronic properties of ZnO thin films deposited by spray pyrolysis using a zinc acetate precursor solution is reported. Analysis of the precursor compound using thermogravimentry and differential scanning calorimetry indicates complete decomposition of the precursor at around 350 °C. Film characterization using Fourier Transform Infrared Spectroscopy (FTIR), photoluminescence spectroscopy (PL), and ultraviolet–visible (UV–Vis) optical transmission spectroscopy suggests the onset of ZnO growth at temperatures as low as 100 °C as well as the transformation to a polycrystalline phase at deposition temperatures >200 °C. Atomic force microscopy (AFM) and X‐ray diffraction (XRD) reveal that as‐deposited films exhibit low surface roughness (rms ≈ 2.9 nm at 500 °C) and a crystal size that is monotonously increasing from 8 to 32 nm for deposition temperatures in the range of 200–500 °C. The latter appears to have a direct impact on the field‐effect electron mobility, which is found to increase with increasing ZnO crystal size. The maximum mobility and current on/off ratio is obtained from thin‐film transistors fabricated using ZnO films deposited at >400 °C yielding values on the order of 25 cm2 V−1s−1 and 106, respectively.
A DFT study on direct benzene hydroxylation catalyzed by framework Fe and Al sites in zeolites

Three-coordinated framework Fe sites in zeolites were theoretically demonstrated to show Lewis acidity and superior catalytic activity for the titled reaction compared with extra-framework Fe sites that were generally considered as the active species, while the corresponding Al sites are not reactive. This catalytic distinctness is ascribed to their divergent α-oxygen structures.
Spectroscopic study of non-covalent complex formation between different porphyrin analogues and quantum dots with lipid-based coating

In this work, we present a steady-state spectroscopic study on the formation of a non-covalent complex between commercially available CdSe / ZnS quantum dots (QD) and differ ent porphyrin-type anionic photosensitizers. The QD surface was coated with lipid-based molecules containing terminal carboxyl groups. Porphyrins with an amphiphilic structure, such as chlorin e 6 , carboxyphenyl and sulphonatophenyl porphyrins with one polar group, were found to form a stable complex with QD with the ability of energy transfer from QD to bound porphyrin molecules. The efficiency of energy transfer from QD to amphiphilic porphyrins was 11–14%. Upon binding to QD, a slightly more efficient energy transfer and well expressed spectral changes were observed for carboxyl- (Ce6, TC1PP) than for sulphonate-porphyrins (TS1PP). In the presence of QD, no significant spectral changes and only a negligible energy transfer (1–2%) were obtained for porphyrins with four polar groups. Based on our findings, we suggest that the formation of a QD-porphyrin complex occurs due to the hydrophobic interaction between the non-polar moiety of amphiphilic porphyrins and the hydrophobic part of the lipid-based QD coating.
Conformational effect of symmetrical squaraine dyes on the performance of dye-sensitized solar cells

A symmetrical squaraine dye altered to possess dicyanovinylene functionality on a carbonyl group of the cyclobutene core (SQM1a) was synthesized to elucidate the effects of the conformationally locked-in cis-like form ensured by the steric repulsion of dicyanovinylenes on the performance of dye-sensitized solar cells (DSSCs) through a comparison with an unsymmetrical analogue bearing one carboxy group (SQM1b) and a standard squaraine dye (MSQ). The FT-IR spectrum of the TiO2 thin film immersed in the dye solution suggested that the linkages between the dye and TiO2 were formed by both carboxy groups symmetrically incorporated on the π-conjugation of dyes. The symmetrical and conformationally locked structure of SQM1a brought about a decrease in the non-radiative decay rate, which may have been induced by suppression of the possible photoisomerization of squaraines. In accordance with the finding of non-radiative decay, a DSSC fabricated with SQM1a exhibited a significantly enhanced short-circuit current density, which revealed an efficient electron injection derived from the double-anchored and conformationally locked structure of SQM1a. Consequently, the performance of DSSCs fabricated with SQM1a was higher than the performance of those fabricated with SQM1b and MSQ. This indicates that substantial advantages can be derived by restricting the conformation of symmetrical squaraine dyes.
Critical impact of mask electromagnetic effects on optical proximity corrections performance for 45nm and beyond

Numerous studies have addressed the challenges ahead in optical lithography due to electromagnetic effects in photomasks (so-called emf effects), which arise from the complex interaction of the illumination with mask topography whose size now approaches the wavelength. As design critical dimensions shrink, the electromagnetic response of the reticle becomes a complicated function of the incident polarization with serious impact to printed critical dimension (CD) on the wafer. A number of modeling techniques are available to approximately account for emf in the process models employed during optical proximity correction calculations, with small to moderate runtime penalty. Among them are simple mask CD bias, the boundary layer [J. T. Azpiroz et al., Proc. SPIE 5040, 1611 (2003)], the domain decomposition method [K. Adam and A. Neureuther, Proc. SPIE 4562, 1051 (2001)], and techniques based on the geometrical theory of diffraction [G. K. Chua et al., Proc. SPIE 5377, 1267 (2004); A. Khoh et al., J. Opt. Soc.
ESTIMATION OF LIMITING EQUIVALENT CONDUCTIVITY AND IONIC RADIUS OF TETRABORATE ANION FROM CONDUCTIVITY MEASUREMENTS OF CONCENTRATED TETRABORATE SOLUTIONS

The conductivities of aqueous solutions of sodium sulphate and sodium tetraborate at different concentrations were measured. Using a novel method, these data were used to determine the limiting equivalent ionic conductivity and ionic radius of tetraborate ion. It was found that the limiting equivalent ionic conductivity of tetraborate ion is 34.58 ohm−1 cm2 and the ionic radius of tetraborate is 3.507±0.076 Å.
Biosorption of lead from aqueous solution by biologically activated date pedicels: batch and column study

Abstract Biosorption of lead by biologically activated date pedicels using a batch system and a continuous up-flow fixed bed column was studied. Batch experiments were conducted to determine the biosorption capacity, equilibrium time and optimal pH. The maximum biosorption capacity of lead was 11.56 mg g−1 at an optimal pH of 5.2. The Langmuir and Freundlich models were used to explain the equilibrium data. The Langmuir model showed a better fit of data with a correlation coefficient of 0.999. The kinetics of biosorption followed pseudo-second-order model. For continuous biosorption experiments, breakthrough curves were analyzed at different flow rates and porosities of the pedicels’ bed. Breakthrough time, time of saturation, fractional capacity and the optimal area of operation were determined. We concluded that biosorption is favored for its lower rate and porosity.
Group-contribution viscosity predictions of liquid mixtures using UNIFAC-VLE parameters

A group-contribution model for both viscosity and activity coefficients prediction for liquid mixtures is proposed. A group-contribution viscosity equation and a group-contribution activity coefficient equation are obtained from the model and expressed by the same group parameters. The group interaction parameters can be determined from viscosity data, activity coefficient data, or both. The group-contribution activity coefficient equation is exactly that of UNIFAC, and for group interaction parameters we use directly the already available UNIFAC-VLE parameters (i.e., interaction parameters are determined from experimental vapor-liquid equilibrium (VLE) data). The viscosity predictions for liquid mixtures can thus be carried out without any viscosity information of liquid mixtures. The viscosity prediction results have been compared with experimental data, and the average deviation between these is generally within 5%
Networked Gold‐Nanoparticle Coatings on Polyethylene: Charge Transport and Strain Sensitivity

Networked films, comprising gold nanoparticles (ca. 4 nm core diameter) and 1,9‐nonanedithiol, are deposited onto oxidized low‐density polyethylene (LDPE) substrates via layer‐by‐layer self‐assembly. Scanning electron microscopy and transmission electron microscopy images reveal a compact coating with a granular, nanoscale morphology. Conductance measurements at variable temperature are consistent with an Arrhenius‐type activation of charge transport (activation energy: 52 meV). The excellent mechanical robustness of the coatings allows for studying their potential application as strain gauges. Expanding the films by up to 3% is accompanied by a reversible and approximately linear increase in resistance of up to approximately 50% (gauge factor ca. 17). Analyzing the results with an activated tunneling model suggests that the average increase in interparticle distances is significantly smaller than the geometric expansion at the substrate surface.
Optimization of CdS buffer layer for high‐performance Cu2ZnSnSe4 solar cells and the effects of light soaking: elimination of crossover and red kink

A spike‐like conduction band alignment of kesterite absorbers with a CdS buffer layer is one of the key factors for high‐performance solar cells using this buffer/absorber heterojunction combination. However, it can also be the origin of fill factor and current‐reducing distortions in current–voltage curves, such as light/dark curve crossover, or an s‐like curve shape for long wavelength monochromatic illumination (red kink) if light‐dependent defect states are present in the buffer layer. In this work, we show that by changing the cadmium precursor source from sulfate to nitrate salts for the chemical bath deposited cadmium sulfide for Cu2ZnSnSnSe4/CdS heterojunction solar cells red kink can be eliminated, and crossover greatly improved (and eliminated entirely after light soaking). These improvements lead to a decrease in series resistance and an increase in fill factor and increase power conversion efficiency from 7.0% to 8.2%. We attribute this improvement to a reduction of deep level acceptor‐like traps states inside the CdS layer, which are responsible for an increase of the conduction band spike up to a current blocking value for the sulfate precursor case. Furthermore, the effects of light soaking will be discussed. Copyright © 2015 John Wiley & Sons, Ltd.
Impact of solvent mixture on iron nanoparticles generated by laser ablation

The present work reveals the structural and magnetic properties of iron oxide (FexOy) nanoparticles (NPs) prepared by femtosecond laser ablation. The FexOy-NPs were produced in solutions consisting of different ratios of water and acetone. Laser ablation in water yields agglomerates and that in acetone yields chain structures whereas that in water/acetone show a mixture of both. We observe significant fabrication dependent properties such as different crystallinities and magnetic behaviors. The structural characterization shows a change from iron (Fe) to a FexOy state of the NPs which depends on the solution composition. Furthermore, transmission electron microscopy measurements exhibit a broad particle size distribution in all samples but with significant differences in the mean sizes. Using magnetic measurements we show that nanoparticles fabricated in pure acetone have lower coercive fields which come along with a smaller mean particle size and therefore increasing superparamagnetic behavior.
Two Pressure Regulated Operons Common in the "Barophiles Branch"

DNA regions corresponding to portions of two different pressure-regulated operons previously identified in two deepsea barophilic bacteria were separately PCR amplified from a variety of deep-sea microorganisms and sequenced. With the two sets of primers employed, amplification was particularly successful from the more barophilic bacteria examined. 16S rRNA sequence analysis revealed that these bacteria are all phylogenetically related and belong in a sub-branch of the genus Shewanella containing only the deep-sea Shewanella barophilic bacteria, which we define as the "Shewanella barophiles branch" containing at least two different species. Our results suggest that the DNA sequences of the pressure-regulated operons can be considered as marker sequences to identify the Shewanella barophilic strains.
Aquatic biodegradation behavior of pentachlorophenol assessed through a battery of shake flask die‐away tests

The aerobic aquatic biodegradability of pentachlorophenol (PCP) was studied in standard Organization for Economic Cooperation and Development/International Organization for Standardization shake flask screening tests for ready biodegradability and in more environmentally realistic surface water die‐away tests with low chemical concentrations. Screening tests were conducted with either activated sludge or supernatant from settled activated sludge. Concentrations of activated sludge were 30 and 0.3 mg suspended solids per liter. Sludges were either freshly collected or initially preexposed to PCP. With supernatant, only low inoculum levels were used (0.5 ml/L). Some surface water tests were carried out with sediment amendment. Added chemical concentrations ranged from 1 to 74,000 μg/L. At nontoxic concentrations, PCP was rapidly biodegradable after an adaptation period of about 10 to 20 d. At concentrations below about 10 μg/L, degradation rates decreased, and the shape of the degradation curves indicated a shift from growth‐linked degradation to non‐growth‐linked degradation. Addition of sediment to surface water reduced the acclimation periods but did not influence the subsequent degradation rate. Preexposure of activated sludge to PCP drastically eliminated the acclimation period and increased the tolerance of the sludge to PCP toxicity. With PCP used as a model compound, the results show that a battery of simple shake flask tests is suitable for provision of a detailed characterization of the biodegradability chemical compounds.
Can Drying Be an Alternative Tissue Preservation Method in Cancer Research Biobanking?

The currently available methods for conservation of biobank material are mainly based on formalin fixation or the use of different freezing techniques. For molecular biological analysis, it is common to use quick freezing and low-temperature storage of the tissue materiel. This is a very energy-intensive and expensive method that requires advanced infrastructure, including monitoring and control procedures. The purpose of this work has been to study drying as an alternative process to cryogenic storage of undried biobank material, especially for use in cancer research groups. Fast freezing has been shown to be suitable to preserve the integrity of RNAs, while traditional formalin fixation preserves proteins and thus morphology in a good way. Various fresh-harvested murine tissues, such as lung, heart, skeletal muscle, liver, and kidney, were quickly frozen in liquid nitrogen and then subsequently dried at +5°C and −10°C, respectively, in a heat pump dryer. After drying, the RNA integrity was measured. The dried material was then stored for five months at +4°C and −20°C in commercial refrigerators, with subsequent measurement of RNA integrity. Dried materials were also evaluated with light microscopy and by electron microscopy with respect to tissue and cell structure. The same pattern was found for all five murine tissues. We conclude that drying at temperatures below 0°C is most careful to preserve the RNA integrity, with approximately the same RIN score of dried and non-dried samples for all five tissues. What characterized the general pattern of stored samples is that drying leads to a preservation of RNA integrity. Moreover, architecture in tissue resembled normal sections prepared from fresh tissue. In some places in the rim of the tissue sample, the lung tissue revealed alveolar-like morphology. In the electron microscope, few organelles other than the nuclei could be identified. Drying of biological material is a promising and cost-effective method for biobanks that store tissue, compared to cryogenic storage of undried material. Degradation of RNA, measured by the RIN number, is a critical factor in storing biobank tissue. In low-temperature dried material, the RIN factor is at the same level as storage of undried material at cryogenic temperatures, which is the common way of storing biobank material today. In this study, a heat pump dryer was used successfully to establish drying temperatures below and above the freezing point of the material. Further work has to be done in order to study different drying methods, drying conditions, and drying costs.
Graphene-wrapped WO3 nanoparticles with improved performances in electrical conductivity and gas sensing properties

WO3/graphene (GN) nanocomposites have been successfully synthesized using a facile three-step synthesis. First, an SrWO4/graphene oxide (GO) precursor was synthesized by homogeneous precipitation; second, the SrWO4/GO precursor was transformed into WO3/GO hybrids by acidification; and third, the WO3/GO hybrids were reduced to WO3/GNvia UV-assisted photoreduction in water instead of general alcoholic solvent at room temperature. The resulting WO3 nanoparticles anchored on graphene sheets as spacers to keep the neighboring sheets separated are approximately quadrangular with a side length of 50–200 nm. Compared with WO3/GO hybrids, WO3/GN nanocomposites show an enhanced electrical conductivity, which results in an improved gas sensing towards alcohol. This work provides a new insight into the fabrication of tungstate–graphene composites and facilitates their application in future.
Electron channeling patterns in the scanning electron microscope

This article provides a comprehensive review of the theory, practice, and application of electron channeling patterns in the scanning electron microscope. An atlas of indexed channeling maps for the bcc, fcc, diamond cubic, and hcp systems is included with a bibliography of 240 references containing all known published work on electron channeling for crystallographic studies in the SEM.