Miracle-dz/UniFAR-FTUs huggingface dataset:
Propriétés optiques des couches minces de SNO2 et CuInS2 airless spray

Dans le present travail, nous avons analyse les caracteristiques optiques des couches minces de SnO2 et CuInS2 preparees par airless spray en vue de leur utilisation en tant que contact avant et absorbeur de la structure photovoltaique backwall CdS/CuInS2. Les donnees experimentales concernent la reflexion R et la transmission T dans les domaines du visible au proche infrarouge. L'interpretation de ces resultats a ete basee d'une part sur la methode d'analyse de R et T developpee par Tomlin et d'autre part sur la methode de resolution numerique d'equations non lineaires de Mueller. Nous avons ainsi obtenu les spectres de dispersion correspondants de n(A) et k(A). Dans le cas de la couche de SnO2, cette etude nous a permis de deduire la permittivite, la masse effective des electrons de conduction et l'energie de Fermi (e∞ = 3,74, m* = 0,34 m0 et EF = 0,64 eV). La loi de variation de e2(ω) en ω-4 obtenue dans la region ωτ >> 1, montre que les porteurs libres sont diffuses essentiellement par les impuretes ionisees. D'autre part, en considerant le materiau inhomogene CuInS2 contenant des inclusions d'air comme etant un milieu effectif, nous avons estime la densite de ces inclusions a environ 20 %. Enfin, cette etude a permis aussi d'evaluer les largeurs de bande interdite du SnO2 et CuInS2 qui sont respectivement de l'ordre de 3,9 eV et 1,4 eV.
Magnetotransport Properties across Verwey Transition in Fe3O4(111) Epitaxial Thin Films

We have studied the magnetoresistance (MR) of high-quality Fe3O4 thin films across the Verwey transition temperature (TV). Different from unsaturated MR observed in many other Fe3O4 films, MR of the present film at a high magnetic field is almost independent of the field, consistent with the fully saturated magnetization. The MR at low field strongly depends on temperature and orientation around TV: While out-of-plane MR sharply decreases from ∼+7 to ∼-5%, in-plane MR abruptly increases from ∼-6 to ∼+3% on cooling across TV.
Incorporation of C60 into poly(methyl methacrylate) and polystyrene by radical chain polymerization produces branched structures

Polymerizations of styrene and methyl methacrylate (MMA) containing 1 wt % C60 initiated by 5 or 10 mol of azobis(isobutyronitrile)/mol of C60 in 1,2-dichlorobenzene solution produce brown polymers in 53−97% yield with all of the C60 incorporated, linear polymer equivalent molecular weights of Pn = 19 000−31 000, and Pw/Pn < 2. There are short induction periods before polymerization begins. All of the C60 is incorporated into the polymer after low conversion of the monomer. Multidetector size exclusion chromatography analyses measured polymer mass by differential refractive index, Mw by two-angle laser light scattering, intrinsic viscosity by differential viscometry, and mass of only C60 derivatives by UV. Molar chromatograms show that all of the polymer at the high end of the molecular weight distributions contains C60, and there are sizeable amounts of a lower molecular weight linear polymer. The high molecular weight polystyrene contains as many as 10−100 C60 units, but the high molecular weight PMMA c.
Supporting Group Discussions with Recommendation Techniques

Group recommender systems (GRSs) have been developed to support group decision making processes with recommendations expected to satisfy a group of people, not just a single person. Most of the previous research has assumed that users’ preferences are stable and independent, and hence systems solely based on individual preferences, in one shot, can predict a group choice. Unfortunately, in practice, what users choose in a group does not fully match their personal taste as the iterative interaction between group members drives them to adapt their behavior and choices to the group setting. Thus, designing effective GRSs necessitates the dynamic support for the group discussion and the decision making process. In this thesis, we aim at leveraging interactive recommendation approaches to facilitate group members in discussing and settling on a final group choice. We particularly focus on: (i) the analysis of how people make decisions in groups, in order to build more useful GRSs; (ii) the development of a GRS that employs and integrates group recommendations into the discussion and decision making stage; (iii) an interactive group model that considers preference knowledge elicited before and during group interaction (i.e., respectively the long-term and session-based preferences); (iv) a generic simulation procedure that simulates social impacts on users’ behavior in order to explore the appropriate combination of longterm and session-based preferences in the alternative group scenarios; and finally (v) a novel group discussion simulation process that models agents’ conflict resolution styles in order to investigate their effect on the outcome of the decision making process supported by the GRS. We have shown in an exploratory user study that the usability score of our system is greater than a standard benchmark and the proposed group model is able to enhance the perceived recommendation quality. The results of various simulation experiments further prove the efficacy of the proposed model in capturing the changes of the users’ preferences, measured in terms of system ranking performance, and indicate that the optimal combination of long-term and the session-based preferences depends on the specific group scenario. Finally, the evidence of our conflict simulation analysis has shed light on how conflict resolution styles are interlinked with other group factors and how they can influence the group recommendation performance, measured by observing the average individual’s loss in utility for selecting the collective choice rather than the personal one, and the difference in utility obtained by the users with the highest and lowest utility in the group.
Novel high birefringent isothiocyanates based on quaterphenyl and phenylethynyltolane molecular cores

We report the synthesis of new laterally alkyl substituted high birefringent quaterphenyl and phenylethynyltolane liquid crystals with isothiocyanate terminal group. The thermal and optical properties such as birefringence are measured and discussed based on their molecular structures. The compounds exhibit birefringence (Δn) in the range of 0.44–0.63, and are expected to be appropriate components of high birefringent nematic mixtures for various applications.
Thermal diffusion and the approach to the steady state in gases: II

The theory of the rate of approach to the steady state in themal diffusion is tested experimentally on the systems He-Ar, He-CO2, H2-CO2, and D2-CO2 over a temperature range of about -78°c to 325°c. The course of the diffusion has been followed by means of the radioactive tracers 37Ar and 14CO2. The theory appears to be verified, and the results are used to calculate ordinary diffusion coefficients, which are in reasonable accord with previous measurements by other techniques. The thermal diffusion factors, which are obtained from the same measurements, also appear to have reasonable accuracy. The experimental method therefore appears to have promise as a sensitive method for the determination of forces between unlike molecules.
Airborne measurements of trace gases using a Chemical Ionisation Mass Spectrometer (CIMS) onboard the FAAM BAe-146 research aircraft

A chemical ionisation mass spectrometer (CIMS) was developed and utilised for measurements onboard the Facility for Atmospheric Airborne Measurements (FAAM) BAe-146 aircraft. The I- ionisation scheme was implemented to detect nitric acid (HNO3), formic acid (HC(O)OH), hydrogen cyanide (HCN) and dinitrogen pentoxide (N2O5) simultaneously at a sampling frequency of 1 Hz. Sensitivities ranged from 35�6 ion counts pptv-1 s-1 for HC(O)OH to 4�0.9 ion counts pptv-1 s-1 for HCN and limits of detection from 37 ppt for HNO3 and 5 ppt for HCN. Trace gas concentrations of species such as HC(O)OH are currently under predicted in global models. In order to understand their role in controlling air quality, it is crucial that their production pathways and abundance are accurately measured and constrained. To date, airborne measurements of these trace gases have been difficult as a result of instrumental limitations on an aircraft such as limit of detection and sampling frequency. The first UK airborne measurements of HC(O)OH and HNO3 confirmed that HC(O)OH is under predicted by up to a factor of 2 in a trajectory model that implements the full Master Chemical Mechanism (MCM) and Common Representative Intermediate Scheme (CRI). The inclusion of a primary vehicle source enabled the model to reproduce the concentrations observed; verifying that direct sources are under represented. Secondary formation of HC(O)OH was observed through its correlation with HNO3 and ozone (O3), indicating a strong photochemical production source. Hydroxyl (OH) concentrations were estimated for the first time in a flight around the UK using the HC(O)OH and HNO3 measurements. A biomass burning (BB) plume identification technique is applied to data obtained from Canadian biomass fires using HCN as a marker. A 6 sigma above background approach to defining a plume resulted in a higher R2 correlating value for the normalised excess mixing ratio (NEMR) to carbon monoxide (CO) when compared to current methods in the literature. The NEMR obtained from this work; 3.76�0.02 pptv ppbv-1, lies within the range found in the literature. This NEMR is then used to calculate a global emission total for HCN of 0.92 Tg (N) yr-1 when incorporated into the global tropospheric model STOCHEM CRI. The first direct N2O5 airborne measurements on an aircraft at night are compared to indirect measurements taken by a broadband cavity enhancement absorption spectrometer. An average R2 correlation coefficient of 0.87 observed over 8 flights for 1 Hz measurements indicates the selectiveness of the I- ionisation scheme to detect N2O5 directly, without nitrate (NO3) interference.
Reaction Rates in Ionic Solutions

Smoluchowski's method of evaluating the fundamental f requency factor for the rate of a reaction like the coagulation of colloid suspension by employing a purely diffusional treatment is extended to include the electrostatic effects arising from the presence of net charges. The introduction of the concept of a diffuse ionic cloud and the potential calculated therefrom leads to the following results: (a) The wellestablished /3ronsted-Debye pr imary salt effect formula is derived. (b) The so-called "solvent" term of the Christiansen-Scatchard equation arising from the self potential of the ions is also derived but appears as the linear approximation of an exponential expression. The conspicuous absence of quantum theory in evaluating the absolute rate of a kinetic reaction merits attention. V. K. LaM. The customary way followed in order to answer the question how reaction rates are influenced by electric charges which may be carried by the reacting particles is that proposed by G. Scatchard a following a derivation of the Bronsted~-Bjerrum 3 activitv relationship given by J. A. Christiansen. 4 On the other hand, the method followed by Smoluchowski 5 for the calculation of the rate of coagulation of colloid suspensions (within the range of rapid coagulation) can certainly be considered as a calculation of reaction rates in a special case. The fundamental question answered by Smoluchowski's treatment is: How many times per second will one of a number, n, of particles per cc. suspended in a liquid be hit by one of the others as a result of their Brownian motion? Smoluchowski obtains the desired number of collisions v per sec. by stating that it can be calculated by solving a diffusion problem in which particles are supposed to diffuse steadily into a hole surrounding the particle in question. At the boundary of this hole the concentration is supposed to be kept 0 and at large dis* Manuscr ip t received July 20, I942. t Professor of Physical Chemistry, Cornell Univers i ty , I thaca, N . Y . a G. Scatchard, J . Am. Chem. Soc. $2, 52 (1930) ; Chem. Rev. 10, 229 (1931). 2 j . N. Bronsted, Z. physik. Chem. 102, 109 (1922); 115, 337 (1925). s N. Bje r rum, Z. physik. Chem. 108, 82 (1924). 4 j . A. Chris t iansen, Z. physik. Chem. 113, 35 (1924). 5 Smoluchowski, Physik. Z. 17, 557, 585 (1916); Z. physik. Chem. 92, I29 (1917).
Peróxido de Hidrogênio: Importância e Determinação

A brief discussion about the hydrogen peroxide importance and its determination is presented. It was emphasized some consideration of the H2O2 as reagent (separated or combined), uses and methods of analysis (techniques, detection limits, linear response intervals, sensor specifications). Moreover, it was presented several applications, such as in environmental, pharmaceutical, medicine and food samples.
An approach to the flame retardancy of EVA copolymer by plasma grafting of acrylic monomers

An attempt has been made in this study to render polymers flame-retardant by a grafting method induced by plasma. Based on ethylene-vinyl acetate (EVA) copolymer with different vinyl acetate contents (%), it was found that the grafting yield was influenced by the plasma treatment conditions and the grafting reaction conditions when EVA copolymer was grafted with acrylic monomers. The flame retardance of the grafted sample was characterized. It was found that the time to ignition of the grafted sample was extended. The limiting oxygen index and char residue were increased. This indicates that the side-group of -COO-Na+ in the grafted layer not only can be charred in the thermal degradation stage, but also can promote charring of the substrate polymer.
Rheological and microstructural transitions in colloidal crystals

The flow of suspensions of 229-nm, charge-stabilized, polystyrene latex particles is directly linked with suspension microstructure. Transitions from long-range orientational order at rest to a steady-state, polycrystalline phase are associated with exceeding the dynamic yield stress. Application of stresses larger than a critical value nucleates a sliding layer microstructure which is accompanied by a discontinuous drop in suspension viscosity. Over a range of shear rates, polycrystalline and sliding layer microstructures coexist. At elevated shear rates, stresses and microstructures fluctuate in time. Shear thickening accompanies the complete loss of long-range orientational order. The transitions in rheology and microstructure are reversible except at very high shear rates where shear thickening accompanies irreversible flocculation. 48 refs., 20 figs., 1 tab.
Kinetics of Boron Sorption and Desorption in Boron Thermal Regeneration System

Boron is used in the primary coolant of pressurized water reactors in nuclear power generation for shim control. If boron concentration is decreased, fewer neutrons are adsorbed and more fission occurs. When boron concentration increases, less fission occurs. The boron concentration can be controlled by the use of ion-exchange resins operating in the Boron Thermal Regeneration System (BTRS). A better understanding of BTRS kinetics can enhance its potential use for chemical shim control. The concentration and temperature effects on boron sorption and desorption with Amberlite IRN-78LC resins are investigated both experimentally and theoretically for BTRS operating conditions from 0.1–0.2 mol/dm3 boron and 10–60°C. A model, based on a postulated boron-sorption mechanism, assuming linear driving force through the film with fast, reversible, local reaction equilibrium, is presented. Comparison with experimental data validates that the model predictions are reasonable. The results are also applicable to other boron ion-exchange systems, such as initial breakthrough predictions from water polishers used in manufacturing microchips.
A Study of The Moisture-Uptake Kinetics of a Hygroscopic Pharmaceutical Powder

AbstractThe moisture-uptake kinetics of a hygroscopic powder, sodium heparin contained in a cylindrical container, was determined using a novel moisture-uptake measuring device under a constant convective air flow. The amount of moisture uptake increased with the increase in the relative humidity of the air. The effect of powder-bed height on the total amount of moisture uptake was found to be significant only at the highest relative humidity (75%) evaluated in this study. However, the percent of weight increase of the powder as a result of moisture uptake decreases as the height of the powder bed increases. The results of this study are explained by the dynamic nature of the moisture-uptake process associated with the instrument.
Characterization of Wastewater for Modelling of Activated Sludge Processes

The fractionation of organic matter in the various parts which are used for mathematical modelling is discussed. The fractions include inert soluble, readily biodegradable, rapidly hydrolysable, slowly hydrolysable, biomass and inert suspended material. Methods for measuring are also discussed. Fractionation of biomass in wastewater and in activated sludge is difficult at present, as methods are only partly developed. Nitrogen fractions in wastewater are mainly inorganic. The organic nitrogen fractions are coupled to the organic COD fractions. The fractions of COD, biomass and nitrogen found in a specific wastewater seem to be constant even when concentrations vary. Wastewater input to sewers and the sewer transport system significantly influences the raw wastewater composition at treatment plants.
Properties of gas source molecular beam epitaxy grown wavelength extended InGaAs photodetector structures on a linear graded InAlAs buffer

The properties of gas source molecular beam epitaxy grown wavelength extended (2.4 µm) InGaAs photodetector structures on a linear graded InAlAs buffer with different grading rates have been investigated by means of XRD and PL techniques in conjunction with optical and atomic force microscopy. Results show that full relaxation and favorable optical characteristics of the active layers only occur for the wafers with a mismatch grading rate of about 1.2% µm−1 or lower, whereas moderate morphology and structural quality could be achieved for a mismatch grading rate up to 2.4% µm−1. A thin GSMBE grown linear graded InAlAs buffer layer of 1.4 µm is sufficient to relax the strain of an InGaAs layer with 1.7% mismatch to the InP substrate and reach a good quality of the wafer. The relaxation mechanisms of the buffer at different grading rates were also discussed.
Ferromagnetism in Pd-rich palladium-iron alloys

Abstract Ferromagnetism has hen detected in disordered solid solution alloys of Fe in Pd at compositions down to 1.25 atomic % of iron. Data are presented on magnetic moments and on Curie points. It is shown that part of the observed magnetic moment must be associated with the Pd atoms, and cannot be completely localized on iron atoms.
The role of oxygen in camphorquinone‐initiated photopolymerization

The activity of camphorquinone (CQ) in the photoinitiation of polymerization at various conditions (in the presence or absence of atmospheric oxygen or a coinitiator) has been studied by UV spectroscopy and differential scanning calorimetry. In the latter case the polymerization kinetics of six multifunctional (meth)acrylates of various structures was followed under isothermal conditions. In the absence of a coinitiator the rate of polymerization was found to depend on the chemical structure of the monomer and its ability to donate hydrogen to exited CQ. For most of the monomers the polymerization rate in air exceeds markedly the polymerization rate in nitrogen, which is in contrast to the situation observed for the polymerization in the presence of a coinitiator (aromatic amine). The increase in the polymerization rate in the presence of atmospheric oxygen is discussed in terms of additional formation of initiating species due to *CQ-assisted decomposition of some oxidation products arising from monomer, polymer or CQ during irradiation.
Stereoselective Polymerization of Styrene with Cationic Scandium Precursors Bearing Quinolyl Aniline Ligands

The novel N-R-quinolinyl-8-amino ligands HL1−5 (R = 2,6-Me2C6H3 (HL1), 2,4,6-Me3C6H2 (HL2), 2,6-Et2C6H3 (HL3), 2,6-iPr2C6H3 (HL4), C6H5 (HL5)) reacted with Sc(CH2SiMe3)3(THF)2 to afford the well-defined complexes (L1−5)Sc(CH2SiMe3)2(THF) (1−5), which were fully characterized by NMR spectral and X-ray diffraction analyses. Complexes 1−3 combined with organoborates to establish binary systems that exhibited high activity for the polymerization of styrene, while 4 was less active and 5 was almost inert. The cationic complex [L1Sc(CH2SiMe3)(DME)2][B(C6F5)4] (6) was successfully isolated by treatment of 1 with [PhMe2NH][B(C6F5)4], and represents probably the structural model of the initiation active species. Remarkably, upon addition of aluminum trialkyls to the binary systems, distinguished improvement in catalytic performances was achieved, among which the ternary system 1/5AliBu3/[Ph3C][B(C6F5)4] displayed the highest activity (1.56 × 106 g mol−1 h−1) and syndioselectivity (r = 0.94) via a chain-end control.
Evaluation of water transport in PEMFC gas diffusion layers using image analysis

Kate Gleason College of Engineering Rochester Institute of Technology Degree: Doctor of Philosophy Program: Microsystems Engineering Name of Candidate: Michael Mario Daino Title: Evaluation of Water Transport in PEMFC Gas Diffusion Layers Using Image Analysis Liquid water transport through the gas diffusion layer (GDL) of a proton exchange membrane fuel cell (PEMFC) was investigated through three interrelated studies utilizing the tools of image processing. First, a new framework and model for the digital generation and characterization of the microstructure of GDL materials with localized binder and polytetrafluoroethylene (PTFE) distributions were developed using 3D morphological imaging processing. The new generation technique closely mimics manufacturing processes and produces realistic 3D phase-differentiated digital microstructures in a costand time-effective manner. The generated distributions of hydrophobic (PTFE) and hydrophilic (carbon) regions representative of commercial GDL materials provides water transport modeling efforts with more accurate geometries to improve PEMFC water management. Second, through-plane transport in an operating PEMFC was investigated by developing and testing a transparent (visible and infrared) fuel cell. Visible observations and subsequent video processing revealed condensation of microdroplets on the GDL and implied the existence of condensation within the GDL. Temperature gradients across the cathode GDL under realistic operating conditions were obtained in a noninvasive manner using infrared imaging and subsequent image analysis. Recommendations for improving accuracy of PEMFC temperature measurements using infrared imaging were made. The final contribution of this work was the measurement and analysis of water breakthrough dynamics across GDL materials with and without microporous layers (MPLs). Dynamic breakthrough events, or recurrent breakthroughs, were observed for all GDL material investigated indicating the breakdown and re-build of water paths through the GDL caused by an intermittent water drainage process from the GDL surface. GDL materials without an MPL exhibited a dynamic breakthrough location phenomenon and significantly elevated water saturations. The results suggest that the MPL not only limits the number of water entries into the GDL substrate but also stabilizes the water paths. These dynamic breakthrough events were explained in terms a Haines jump transport mechanism. The main contributions of this work are: (1) Development of a new digital GDL microstructure generation algorithm, (2) Evaluation of infrared temperature measurements in the through-plane direction of a PEMFC, and (3) Identification of a new water transport mechanism in GDL materials. Abstract Approval: Committee ChairApproval: Committee Chair