Miracle-dz/UniFAR-FTUs huggingface dataset:
Size effects in the excited electronic states of small colloidal CdS crystallites

This paper reports experimental studies of the development of bulk optical properties as a function of crystallite size for the inorganic direct gap semiconductor CdS. Small crystallites are synthesized via colloidal chemical techniques, and their optical properties are studied in situ at extreme dilution. The crystallites are characterized via high resolution transmission electron microscopy. Direct images show (111) lattice planes, and establish the crystallite structures as close to those of excised fragments of bulk CdS (zinc‐blende cubic). Large crystallites (> 100 A average diameter) show an optical absorption, in colloidal solution, close to that of bulk crystalline material. However, small crystallites of 30 A average diameter show a large blue shift (∼0.8 eV) in absorption edge (effective band gap), and an intensification of edge absorption relative to absorption at higher energy regions. These observations can be understood as quantum size effects resulting from confinement of an electron and ho.
Influence of transverse magnetic field on expansion and spectral emission of laser produced plasma

The expansion of a copper laser produced plasma across a 320 mT magnetic field was investigated using time- and space-resolved optical emission spectroscopy. Time-of-flight Langmuir probe ion measurements were used to characterize the plume expansion in the absence of the magnetic field. The spectroscopy measurements reveal that the magnetic field gives rise to substantial confinement of the plasma emission. The field also leads to significant enhancement of the intensity of some of the neutral and ion emission lines.
A Novel Glass Membrane for Low Temperature H2/O2 Fuel Cell Electrolytes

A novel structure for an H2/O2 fuel cell with a proton conducting glass electrolyte and a Pt/C catalyst was developed. The performance of the fuel cell, which was impregnated with a glass electrolyte and a gaseous hydrogen–oxygen feed at low temperature in a humidified atmosphere was significantly improved by introducing membrane electrode assemblies (MEAs) consisting of heteropolyacids (HPAs) (phosphotungstic acid, PWA and phosphomolybdic acid, PMA) doped with a P2O5‐SiO2 glass electrolyte. The HPAs containing porous glass electrolytes show promise for applications in low temperature H2/O2 fuel cells. The electrochemical behaviour of these materials was studied by measuring the current–voltage profile from polarisation curves. A maximum power density of ≈ 35 mW cm–2 was obtained at 30 °C and 30% RH (relative humidity) using a PMA/PWA‐P2O5‐SiO2 glass electrolyte membrane. The impedance measurements displaying the total cell ohmic resistance for 12 h at 0.5 V were evaluated at 30 °C. The resistance value was 3.5 Ω for an operating time of 12 h. This MEA showed the best and the most stable performance for use in an H2/O2 fuel cell.
Carbon doping of self-organized TiO2 nanotube layers by thermal acetylene treatment

Self-organized layers of TiO2 nanotubes were formed by electrochemical anodization of Ti in a HF/Na2HPO4 electrolyte. The tubes were treated at 500 °C under a mixed flux of N2 and acetylene (C2H2). The samples were characterized using SEM, XRD and photoelectrochemical measurements. The results show that the acetylene treated tube layers exhibit a significant photoresponse over the whole range of visible light up to the near-IR region (1.5 eV). This carbon doping treatment at comparable mild conditions does not lead to any structural damage to the morphology of the nanotubes.
Experimental investigations of polymer gel dosimeters

Polymer gel materials continue to show promise as 3D dose verification tools in radiotherapy, particularly given the ever-increasing complexity of modern radiation therapy treatment techniques. To date different polymer gel formulations have been explored as potential 3D dosimeters, each with different characteristics. Although the fundamental processes (e.g. polymerization) occurring in many of these dosimeters share common principles, experimental and environmental factors (e.g. gel irradiation temperature) can differentially affect the different polymer gel dosimeters. This dependence can further be amplified or suppressed depending on the imaging modality used to extract the dose information from the polymer gel. This paper reviews the experimental investigations of the fundamental processes occurring in irradiated polymer gel dosimeters, including monomer consumption, polymerization, gelation, and gel ageing. The experimental and environmental factors which affect these processes during, and post, gel irradiation are also discussed. Finally, since the body of literature pertaining to basic investigations in polymer gel dosimetry is ever expanding, some effort is made to catalogue both published experimental work as well as unexplored research areas in the field.
Synthesis and characterization of strongly fluorescent europium-doped calcium sulfide nanoparticles

Nanometer-sized europium-doped calcium sulfide (CaS–Eu) particles were synthesized for the first time for potential use in bioassays, in particular, in biochip-based analysis. The CaS–Eu nanoparticles were prepared through a wet chemical process in ethanol. The average diameter of the nanoparticles was about 15 nm. They were characterized by UV–Vis spectrometry, scanning electron microscopy, X-ray diffraction, fluorescence spectroscopy and X-ray sequential fluorescence spectroscopy. Both electron paramagnetic resonance measurement and an extensive washing experiment revealed that the dopant atoms were internal ions dispersed throughout the whole CaS–Eu nanoparticles. Factors affecting the fluorescent properties of the nanoparticles were examined. It was found that the emission wavelength of the CaS–Eu nanoparticles could be altered by partial replacement of calcium with other alkaline earth metals such as magnesium, strontium and barium, and this makes the nanoparticles ideal for use as biochips where a multicolor-based bioassay is common.
Size-controlled synthesis of silver nanoparticles using Zizyphus mauritiana fruit extract

We demonstrated size-controlled synthesis of silver nanoparticles (AgNPs) using Zizyphus mauritiana fruit extract from an aqueous solution of silver nitrate. The size distribution of the resulting AgNPs were found to be dependent on the con- centration of fruit extract and reaction time, at the same concentration of silver nitrate. The AgNPs were characterised by UV-Visible spectroscopy (UV-Vis), particle size analysis (DLS), atomic force microscopy (AFM), transmission electron microscopy (TEM) and X- ray diffraction (XRD). The sizes of the AgNPs were found to decrease with the increase of concen- tration of fruit extract from 300 nm to 70 nm. The increase in reaction time from 5 min to 20 min significantly decreases the size of the AgNPs from 350 nm to 100 nm.
Controlling the oxygen species density distributions in the flowing afterglow of O2/Ar–O2 surface-wave microwave discharges

The evolution of species densities along a reactor radially positioned on an O2 surface-wave microwave discharge is investigated by means of modelling with the aim to define the density tuning possibilities. The validity of the models is shown by the comparison of the calculated and measured axial distribution of O-atoms. The calculations revealed that due to the perpendicular injection of the plasma into the reactor, the gas temperature is close to the room temperature in most of it, except for a 5 cm region around the inlet. It is shown that the pressure drop along the discharge tube, which results in the change of pressure in the discharge region with the gas flow rate, induces the variation of the relative density of active species entering the reactor, where the pressure is kept constant. The surface recombination probability of atoms varies along the afterglow tube due to the surface temperature gradient, as well as due to the conditioning of the surface resulting from the continuous operation of the system. The system is shown to be very practical in applications where surfaces/porous materials are to be treated homogeneously by pumping active species through them, since by tuning the gas flow rate equidensity surfaces can be obtained in the case of the two most abundant species, the O-atoms and O2(a) molecules. In the case of O-atoms the densities obtained at the two pressures investigated, i.e. 100 and 50 Pa, are very similar, as well as their evolution along the reactor, while the density of O2(a) molecules decreases considerably with pressure.
Adherent-invasive Escherichia coli Biofilm Formation Assays

[Abstract] Patients with Crohn’s disease are abnormally colonized by adherent-invasive Escherichia coli (AIEC) bacteria (Chassaing and Darfeuille-Michaud, 2011). These bacteria are able to adhere to and invade intestinal epithelial cells (IEC), to replicate within macrophages, and were recently described to be able to form biofilms (Martinez-Medina et al., 2009; Chassaing and Darfeuille-Michaud, 2013). The reference strain of adherent-invasive E. coli is the strain LF82, associated with ileal Crohn’s disease (Darfeuille-Michaud et al., 1998). This protocol described basic steps of a biofilm formation assay on I) non-cell-treated polystyrene microtiter plates and on II) paraformaldehyde-fixed I-407 IEC monolayers.
Unusual tuning of mechanical properties of thermoplastic elastomers using supramolecular fillers

Supramolecular fillers were incorporated in a poly(-caprolactone)-based polyurea in a modular approach via a "perfect-fit" principle. DSC and AFM studies both support the same model in which the bis- (ureido)butylene-based filler molecules are incorporated into the bis(ureido)butylene hard segment domains of the polymer via bifurcated hydrogen-bonding interactions up to 23 mol % () 7.3 wt %) of incorporated filler. Polymer hard segment and filler form a single phase, and the soft phase remains unaffected. This resulted in stiffer materials (23 mol % of incorporated filler more than doubled the Young's modulus) without a decrease in tensile strength or elongation at break. When more than 23 mol % of filler was added to the polyurea, separate filler crystallites were observed in both AFM and DSC. A drop in Young's modulus was now observed, followed by an increase upon adding even more filler. In this second regime, a decrease in tensile strength and elongation at break was observed, revealing similar behavior to reinforcing thermoplastic elastomers with the more common micrometer-sized reinforcement fillers.
Controllable gas-liquid phase flow patterns and monodisperse microbubbles in a microfluidic T-junction device

This letter describes the gas-liquid phase flow patterns and the mechanism of generation of monodisperse microbubbles in a T-junction microfluidic device using the crossflowing shear-rupturing technique. The bubble size is ranged from 100 to 500μm. The air phase states as isolate air slugs, “pearl necklaces,” periodic isolate bubbles, zig-zag bubble patterns, and multiple-bubble layer can be observed in the wider measured channel. The bubble size relates with the continuous phase flow velocity and viscosity as Vb∝1∕(μcuc), while being almost independent of surface tension γ and air phase flow rate Qg, for the conditions used in this work. The bubble formation mechanism by using the crossflowing shear-rupturing technique is different from the hydrodynamic flow focusing and both geometry-dominated breakup techniques. Our system provides independent control of both the size and volume fraction of dispersed bubbles.
NMR Investigations of Clostridium pasteurianum Rubredoxin. Origin of Hyperfine 1H, 2H, 13C, and 15N NMR Chemical Shifts in Iron−Sulfur Proteins As Determined by Comparison of Experimental Data with Hybrid Density Functional Calculations†

High-level, all-electron, density functional calculations on a 104-atom model (B3LYP/6-311G** level) have been used, in conjunction with high-resolution X-ray structural data, to predict the remarkable paramagnetic contact shifts recently measured for 1H, 2H, 13C, and 15N nuclei in Clostridium pasteurianum rubredoxin. Three published X-ray structures for the Fe(III) rubredoxin from C. pasteurianum were employed to construct a 104-atom model for the iron center that included all atoms shown to have strong electronic interactions with the Fe. Each of these models served as a starting point for quantum mechanical calculations at level B3LYP/6-311G**, which, in turn, yielded calculated values for Fermi contact spin densities. The results indicate that the experimental hyperfine shifts are dominated by Fermi contact interactions: calculated Fermi contact spin densities were found to correlate linearly with isotropic hyperfine 1H, 2H, 13C, and 15N NMR chemical shifts determined for Fe(III) rubredoxin. At the c.
PHASE TRANSITIONS OF POLY(VINYLIDENE FLUORIDE) UNDER ELECTRIC FIELDS

ABSTRACT The electric poling behavior of poly(vinylidene fluoride) (PVDF) films was investigated by Fourier transition infrared spectrum (FT-IR), ferroelectric and piezoelectric effect test in this paper. PVDF undergoes a structural evolution under electric fields over a wide range of electric fields from 0 to 180 MV/m. The phase transitions were characterized as α phase to β phase via middle δ phase with increase of poled electric field intensity. According to ferroelectric hysteresis performance of PVDF films, it could be found that the trend of piezoelectric coefficient d33 which increased with poled electric field intensity was coincident with Boltzmann distributing function. And the results indicated that the range of the poled electric field intensity which brought the maximal remnant polarization was 100–125 MV/m, the maximal piezoelectric coefficient d33 for β phase of PVDF films was achieved 28 pC/N.
SORPTION OF CADMIUM FROM AQUEOUS SOLUTIONS BY CHEMICALLY PRE -TREATED CHITIN

Chitin was chemically pre-treated in order to improve its sorption performance to metallic ions in wastewater. The pre-treated chitin was evaluated as sorbent material for cadmium ions in aqueous solutions by using equilibrium isotherms and kinetics of adsorption. Except the pre-treatment I, the sorption rates of cadmium are higher on the pre-treated chitin than of the untreated ones. The maximum cadmium uptake of pretreated chitin was quantitatively evaluated using sorption isotherms. Langmuir model gave a good fit to the experimental equilibrium data. Before the pre-treatment, chitin exhibited relatively low sorption to cadmium ions. The pre-treated chitin showed an increased sorption, due to the partial transformation of amide to amine groups. The maximum sorption capacities of cadmium on the pretreated chitin were 20.68 mg/g and 16.27 mg/g at pH 8 (pretreatments III and II respectively), 18.39 mg/g with NaOH 0.1M, which were higher than that of the untreated chitin 14.21 mg/g.
Flowing versus Static Conditions for Measuring Multiple Exciton Generation in PbSe Quantum Dots

Recent reports question the validity of pulsed fs-laser experiments for measuring the photon-to-exciton quantum yields (QYs) that result from multiple exciton generation (MEG). The repetitive nature of these experiments opens up an alternative relaxation pathway that may produce artificially high results. We present transient-absorption (TA) data for 4.6 and 6.6 nm diameter PbSe quantum dots (QDs) at a variety of pump photon energies. The data are collected under laminar flow conditions with volumetric flow rates ranging from 0 to 150 mL/min (resulting in Reynolds numbers up to 460). The results are modeled with a spatially resolved population balance of generation, recombination, convective replacement, and accumulation of long-lived excited QDs. By comparing the simulations and experiments, the steady-state population of the long-lived QD-excited states and their kinetics are determined for different experimental conditions. We also improve upon reported photon-to-exciton QYs for PbSe QDs. We find diffe.
Growth and Heavy-Metal Uptake by Lettuce Grown in Soils Applied with Sewage Sludge Compost

A pot experiment was conducted to investigate the effect of sewage sludge compost (SSC) alone and applied with chemical fertilizer on growth and heavy-metal accumulations in lettuce grown on two soils, a Xanthi-Udic Ferralosol and a Typic Purpli-Udic Cambosol. The treatments included control; nitrogen–phosphorus–potassium (NPK) fertilizer; sewage sludge compost applied at the rates of 27.54 (SSC), 82.62 (3SSC), 165.24 (6SSC) t hm–2; and coapplication treatment (1/2 SSC + 1/2 NPK), where the N, P, and K inputs from NPK fertilizer, SSC, and coapplication treatments were normalized to the local recommend rates. The SSC application increased the biomass; copper, zinc, and lead contents in lettuce; and soil total and diethylenetriaminepentaacetic acid (DTPA)–extractable metals. However, SSC alone at the recommended rate caused less plant biomass than NPK fertilizer alone. Coapplication treatment obtained greater or similar biomass to NPK fertilizer alone and did not increase heavy-metal accumulation in soils and plants. The results demonstrated that SSC should be applied to soils with chemical fertilizers.
Vibrational analysis of boldine hydrochloride using QM/MM approach

A complete vibrational analysis was performed on the molecular structure of boldine hydrochloride using QM/MM method. The equilibrium geometry, harmonic vibrational frequencies and infrared intensities were calculated by QM/MM method with B3LYP/6-31G(d) and universal force field (UFF) combination using ONIOM code. We found the geometry obtained by the QM/MM method to be very accurate, and we can use this rapid method in place of time consuming ab initio methods for large molecules. A detailed interpretation of the infrared spectra of boldine hydrochloride is reported. The scaled theoretical wave numbers are in perfect agreement with the experimental values. The FT-IR spectra of boldine hydrochloride in the region 4000-500 cm(-1) were recorded in CsI (solid phase) and in chloroform with concentration 5 and 10 mg/ml.
Physicochemical Study of the Cotton Cellulose— Dimethylolpropyleneurea Reaction1

Physical and chemical properties of cotton print cloth treated with 0.55 M solutions of 1,3-bis(hydroxymethyl)-2(1H)-tetrahydropyrimidinone (dimethylolpropyleneurea or DMPU) in the presence of 0.03 and 0.1 M inorganic salt catalysts have been determined. The kinetics of the reaction in the presence of 0.03 M catalysts have been investigated. Specific reaction-rate constants at 45, 55, and 65°C in the presence of ZnCl2, Zn(NO 3)2, MgCl2, and Mg(NO3)2 have been calculated by following the changes in nitrogen and formaldehyde contents. Changes in crease recovery properties of finished fabrics with changes in nitrogen and formaldehyde contents were also followed. Enthalpies, entropies, and free energies of activation at 45°C for the reaction have been calculated. Specific reaction-rate constants and activation parameters were compared with those values reported previously for the reactions of cotton with derivatives of ethyleneurea. Infrared spectral data of fabrics finished with DMPU were analyzed.
Egypt's cultural heritage in conflict situations: examination of past and present impact

In recent decades, the remarkable cultural heritage of Egypt has been threatened by loss or damage due to many conflict situations. These have led to looting, smuggling, vandalism, encroachment, illegal activities, and many more threats which put the fate of Egypt’s heritage in jeopardy of disappearance and demolition. The loss of Egyptian heritage is not only a loss of history, but of cultural identity, memory and existence. These types of threats are by no means a recent phenomenon, but have been going on for centuries. This paper presents a research into the history of Egyptian heritage in times of conflict especially in the 19th and 20th centuries. Furthermore, it also examines the severe crisis that endangered Egyptian heritage in the 21st century, notably the aftermath of the 2011 Revolution and the subsequent, widespread pillaging of archeological sites and museums. These recent conflicts highlighted concerns about the future of Egyptian antiquities and their protection, and raised serious concerns about how to protect Egyptian patrimony and preserve the collective cultural memory of Egypt. A comprehensive, comparative analysis of Egyptian and international legislation pertraining to cultural heritage protection has been conducted in order to examine its efficiency in protecting Egypt’s cultural heritage.
Square Arrays of Vertical Cylinders of PS-b-PMMA on Chemically Nanopatterned Surfaces

Cylinder-forming polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) thin films were directed to assemble on chemically nanopatterned surfaces consisting of a square array of spots with varying diameters of lattice spacing and spot size. In all cases the patterned spots were preferentially wet by the PMMA block in a continuum of surface wet by the PS block. On this chemical pattern, cylindrical domains oriented perpendicular to the surfaces formed a square array of vertical cylinders, instead of a hexagonal array typically formed in the bulk morphology of cylinder-forming block copolymers. When the lattice spacing of chemical spot patterns was incommensurate with the natural dimension of diblock copolymer in a square array, surface reconstruction led to the formation of microdomain structures that do not appear naturally in the bulk state, such as a loop structure of PMMA cylinders connecting two neighboring PMMA cylindrical sections, and semicylinder domains located at the center of the square unit c.
Resolution of discrete and continuous molecular size distributions by means of diffusion-ordered 2D NMR spectroscopy

Diffusion-ordered 2D NMR (DOSY) experiments have been developed for the analysis of mixtures. These experiments yield conventional chemical shift spectra in one dimension and spectra of diffusion coefficients (or approximate molecular radii) in the other. At the heart of this method are the analysis and display of data obtained with pulsed field gradient (PFG) NMR techniques. At each point on the chemical shift axis, a set of intensities is obtained as a function of K 2 (K=γgδ, whore γ is the magnetogyric ratio and g and δ are the gradient pulse amplitude and duration, respectively)
Qualitative analysis of mango cv. Langra influenced by various postharvest treatments

To evaluate the influence of various postharvest treatments on the chemical characteristics of mango cv. Langra, the present laboratory investigation was carried during 2016-17. Disease and bruises free, fresh fruits of uniform size, shape and colour were harvested at physiological mature stage and were given various postharvest treatment of sodium hypochlorite (NaOCl: 100, 150, 200ppm), 6-benzyladenine (BA: 50, 100, 150ppm) and hot water (52 to 55o C) for 5, 10 and 15 minutes. The fruits were subjected to air dried and kept in 5 ply corrugated boxes (5% ventilation) with newspaper lining and stored in ambient conditions. The fruits were evaluated after 3, 6, 9 and 12 days of storage. Total soluble solids (TSS) and sugars content of the fruits increased steadily up to 9 days and thereafter declined gradually whereas, sugar acid ratio (SAR) increased linearly during storage. Titratable acidity and ascorbic acid content gradually decreased linearly whereas, beta carotene content of fruits increased linearly during storage. Fruits treated with BA @ 100ppm and HWT for 5 minutes significantly maintained higher TSS, sugars and antioxidants content of the fruits and remained acceptable up to 12 days under ambient storage conditions.