Miracle-dz/UniFAR-FTUs huggingface dataset:
Hydrophobicity, hydrophilicity and two-phase flow in the gas diffusion layer of a polymer electrolyte fuel cell

Polymer electrolyte fuel cells (PEFCs) are versatile electrochemical devices that convert the chemical energy of a fuel, such as hydrogen, and an oxidant, such as air-derived oxygen, directly into electricity, both cleanly and efficiently. In spite of their promise as alternative energy sources, design issues remain when the cell operates at high current density: condensing water vapour at the reacting catalyst layer, on the cathode side of the cell, blocks the pores in the gas diffusion layer (GDL), which is detrimental to cell performance. Substantial experimental evidence indicates that using a hydrophobic, rather than hydrophilic, GDL on the cathode alleviates the problem. However, whilst existing theory confirms the advantages of using a hydrophobic GDL, it does not simultaneously confirm the disadvantage of using a hydrophilic GDL. This thesis uses a combination of asymptotic and numerical methods to investigate this apparent anomaly by considering an isothermal, steady state, generalized Darcy model for two-phase flow in a porous medium; mathematically, this leads to a free-boundary problem to determine the location of the interface between one-phase and two-phase flow. After extensive analysis, it is found that the model predicts significant differences between the flow regimes found in hydrophobic and hydrophilic GDLs. Furthermore, the model results show that hydrophobic GDLs are found to lead to higher current density, and hence better cell performance, than hydrophilic GDLs, as is the case in experiment. The importance of temperature differences across the GDL is also analysed by means of a non-isothermal model. It is found that temperature gradients in the GDL significantly affect the cathode overpotential and outlet temperature at which the onset of two-phase flow occurs; high enough overpotential can lead to the return of gas-phase only flow, which is not the case in the isothermal model.
Synthesis and magnetic properties of polymer nanocomposites with embedded iron nanoparticles

Magnetic nanoparticles embedded in polymer matrices have excellent potential for electromagnetic device applications like electromagnetic interference suppression. We have synthesized polymer nanocomposites of poly(methylmethacrylate) doped with varying concentrations of iron nanoparticles (∼20 nm in size). The iron nanoparticles were produced using a microwave plasma technique and have a natural oxide surface layer for passivation. These nanocomposites were processed using melt blending technique. The polymer processing conditions were optimized to achieve good uniform dispersion of the nanoparticles in the polymer matrix. The concentration and dispersion of nanoparticles were varied in a controlled way. Surface characterization with scanning electron microscopy indicates that, to a large extent, the iron nanoparticles are embedded in the bulk; the surface mainly showed features associated with the polymer surface. Static magnetic properties such as susceptibility and M–H loops were studied using a physi.
Improved preparations of ionic liquids using microwave irradiation

Controlled, multimode microwave irradiation has been employed in a generic solvent-free process to prepare a wide range of ionic liquids based on nitrogen-containing heterocycles. The developed method offers a flexible, small to large-scale approach to prepare ionic liquids, in either sealed or open vessels, in a faster and greener process than any previously described.
CHEMICAL AND SENSORY PROPERTIES OF VERJUICE, A TRADITIONAL TURKISH NON‐FERMENTED BEVERAGE FROM KABARCIK AND YEDIVEREN GRAPES

Verjuice is an unfermented green grape juice obtained by pressing green grapes. It has a unique flavor and sour taste. In the present study, parameters on the quality properties of verjuice made from Kabarcik and Yediveren grape varieties were studied; turbidity of fresh verjuice samples were 57.3 and 59.57 (625 nm %T), respectively. Phenolic matter contents ranged between 626.27 and 753.80 (mg/100 mL). In the samples treated with heat, clarified with gelatin and stored at 4C, the turbidity values were 81.20 and 93.10 (625 %T), and the total phenolic matter contents were 270.21 and 227.48 mg/100 mL in Kabarcik and Yediveren varieties, respectively. In addition, according to sensory evaluation, verjuice samples clarified with gelatin were preferred most by the panelists. PRACTICAL APPLICATIONS Verjuice is an unfermented green grape juice obtained by pressing unripe grapes with a unique flavor and sour taste. It is traditionally produced by pressing grapes and sieving the juice obtained through a nonmetal. It is preserved in bottles, adding olive oil to prevent contact with air, at cool condition. It is consumed locally, especially in the Mediterranean and southeastern regions of Turkey, to enhance the flavor of traditional meals, salads and appetizers, and as an ingredient in the production of various drinks, and several sausages such as mustard sausage. The natural verjuice that is neither clarified nor heated was more flavored, but it is turbid and has rather short shelf life. The present study revealed that clarification with gelatin followed by heat treatment of bottled verjuice at 85C for 15 min result in a favorable product with respect to quality properties during shelf life at ambient temperature.
Internal stresses in Cr, Mo, Ta, and Pt films deposited by sputtering from a planar magnetron source

Extensive investigations of the internal stresses, electrical resistivities, optical reflectances, and microstructures of metal and semiconductor films sputtered from cylindrical‐post magnetron sources have established the existence of a universal transition phenomenon for these properties that depends sensitively upon the pressure of the sputtering gas and its mass relative to that of the target material. At low working pressures the sputtered films generally have compressive stresses and near bulk‐like values of their resistivity and optical reflectance. Little change is observed as the working pressure is raised, until a transition pressure is reached at which rapid changes in the deposited film properties begin to occur. The transition pressures for the various elements increase in a regular way with their atomic masses. A preliminary study by one of the authors also indicated that the values of the transition pressures were sensitive to the geometry of the sputtering source, being lower for sources o.
Stabilization and optical switching of liquid crystal blue phase doped with azobenzene-based bent-shaped hydrogen-bonded assemblies

We develop a new kind of bent-shaped hydrogen-bonded assemblies (H-bonded assemblies) to stabilize liquid crystal blue phases (LC-BPs) and optically switch the Bragg reflection band of BPs. Here the H-bonded assemblies are simply assembled with the proton acceptor containing azobenzene mesomorphic group and diacid proton donors. The BPs temperature ranges of the LC samples are significantly widened by H-bonded assembly dopants, and the widest BP temperature range is 16.7 °C. Moreover, the lower temperature of BPs is very close to room temperature. Additionally, a blue-shift of the Bragg reflection bands with the corresponding reflection color from green to blue is observed in the LC sample doped with H-bonded assemblies upon UV light irradiation. The related physics mechanisms for the stabilization and optical switching of BPs may be contributing to the bent-shaped molecular geometry of H-bonded assemblies and photoisomerization of azobenzene moiety in H-bonded assemblies, respectively. This work opens up a way to design self-organized molecules suitable for optically tuning BP display and other photonic devices.
Chemical Conditions Conducive to the Release of Mobile Colloids from Ultisol Profiles

The objective of this study was to determine how soil pH (4.3-6.9), low total electrolyte concentration (TEC, 0.4-2.8 mol{sub c} m{sup -3}) and low Na adsorption ratios (SAR, 0.3-1.8 [mol{sub c} m{sup -3}]{sup 0.5}) affected the concentration of mobile colloids released from 13.5-m{sup 3} reconstructed Ultisol profiles. Critical flocculation concentration (CFC, the minimum TEC to induce flocculation of a clay suspension) tests were conducted using the water-dispersible clay fraction of the Ap horizon of these profiles, which is the primary source for the mobile colloids. Surface soil pH, TEC, and SAR levels of the profiles that released high concentrations of colloids fell within the dispersion domain identified by the laboratory CFC tests. The effect of SAR on dispersion appears to be a continuum that approaches zero, and this effect is significantly (P = 0.01) dependent on TEC. This dispersible nature of these soils is in part attributed to their very low TEC, generally < 2 mol{sub c} m{sup -3}, which results from low concentrations of weatherable minerals. The TEC of 10 of the 13 profiles were < 2 mol{sub c} m{sup -3}, the CFC for SAR = 1 (mol{sub c} m{sup -3}){sup 0.5}, indicating that if the pH is notmore » limiting (pH greater than = 6.0), colloidal dispersion will occur. 24 refs.« less
Exploring the physicochemical basis of cheese texture, rheology and functionality, with emphasis on cation-casein interactions

Title Exploring the physicochemical basis of cheese texture, rheology and functionality, with emphasis on cation-casein interactions Author(s) Cooke, Darren Richard Publication date 2014 Original citation Cooke, D. R. 2014. Exploring the physicochemical basis of cheese texture, rheology and functionality, with emphasis on cation-casein interactions. PhD Thesis, University College Cork. Type of publication Doctoral thesis Rights © 2014, Darren R. Cooke. http://creativecommons.org/licenses/by-nc-nd/3.0/
Kinetic Entrapment of a Hidden Curcumin Cocrystal with Phloroglucinol

The existence of a cocrystal between curcumin (CUR) and phloroglucinol (PHL) was suspected but could not be demonstrated in a recent systematic effort to synthesize novel curcumin cocrystals. We hypothesize that the elusive CUR–PHL cocrystal is a kinetically stable form that can be prepared by trapping it using a fast solvent removal crystallization process. The polarity of crystallization solvent and relative solubility of cocrystal formers in the solvent appear to be critical parameters governing the phase purity of the resulting cocrystal. Organic solvents of higher polarity and in which the cocrystal formers exhibited congruent solubility tended to afford a purer cocrystal phase. Essentially phase-pure CUR–PHL cocrystals were successfully obtained from acetone, and their 1:1 stoichiometry was confirmed by differential scanning calorimetry and solid state nuclear magnetic resonance spectroscopy. Compared with the individual component phases, the cocrystal displayed reduced hygroscopicity and improved t.
Encapsulation of vegetable oils by miniemulsion polymerization: mathematical modeling

Miniemulsion polymerization reactions of MMA were conducted with encapsulation of vegetable oils, using different types (linseed and andiroba oil) and amounts of oils. It was observed a decrease in the reaction rate that was proportional to the number of double bonds present in the oil. Polymers with lower molecular weights were obtained when oils with higher number of double bonds were used. A mathematical model was developed to represent the kinetics of these reactions, including all the other kinetic mechanisms associated to free radical miniemulsion polymerization. The model was able to predict the variation in the polymerization reaction rate depending on the type and amount of the vegetable oil.
City Research Online

This paper is a response to the call for models of organization design as a science revealing the inner composition of organization and specifying the laws to be respected when crafting it. It maintains that the needed science is a chemistry of organization, addressing the combination of ‘organizational elements’ playing a role analogous to that of chemical elements in composing a variety of substances. Drawing both on classic organization design theory and on configurational and complementarity-based approaches, the paper specifies a set of basic organizational elements and a set of combinatory laws regulating their effective combinations. Testable propositions are derived on the necessary and sufficient conditions that the composition of organizations should respect for achieving high levels of efficiency and innovation. These propositions are tested empirically on a sample of firms, using an innovative application of Boolean algebra.
Outcome Analysis of Cisplatin-5 Flurouracil and Weekly 5-Flurouracil in Advanced Gastric Cancer.

Background: Advanced gastric cancer patients has poor survival rate of < 20% at 5 years. We intended to evaluate the outcomes of Cisplatin and 5-Flurouracil combination chemotherapy or 5 FU alone in this setting. Objectives: In this study we analyzed the outcomes such as response rate, progression free survival (PFS) at 6 months, and toxicity profiles of 3 weekly Cisplatin and 5-Flurouracil (PF) regimen and Weekly 5-Flurouracil (5-FU) therapy in advanced gastric cancer. Subjects and Methods: The outcomes of the chemotherapeutic regimens such as intravenous infusion of Cisplatin 75mg/m2 in divided doses and 5-Flurouracil 750mg/m2 for consecutive 3 days every 21 days (Group A) and intravenous infusion of 5-Flurouracil 500mg flat dose every week for 16 weeks (Group B) in stage III/IV gastric cancer were analyzed. Baseline parameters were obtained. Results: Twenty patients for both PF and weekly 5-FU regimens were recruited. The Overall response rate of Group A and B regimen was 40% and 20% respectively. PFS at the end 6 months was 60% and 35% respectively. Median time to progression was 5 months in group A and 3.6 months in group B. Hematological toxicity and Non hematological toxicity rates were in the acceptable range in Group A. Conclusion: Three weekly Cisplatin and 5-Flurouracil could be a good regimen when the performance status of the patient is good. Weekly 5-Flurouracil gives good quality of life and this regimen can be considered when the patient is not eligible for Cisplatin and 5-Flurouracil regimen in advanced gastric cancers.
DFT Calculations for Cu-, Ag-, and Au-Containing Molecules

CuH, CuO, CuS, Cu2, CuCl2 - , CuCH3, CuC2H2 ,C u 2(HCO2)4(H2O)2, and Cu6H6(PH3)6 and the silver and gold diatomics AgH, AgO, AgS, Ag2, AgCu, AuH, AuO, AuS, Au2, AuCu, and AuAg. The DFT methods used were SVWN, BLYP, and BPW91, together with the DFT hybrids B3LYP and B3PW91. The calculations were carried out with the basis sets LANL2MB, LANL2DZ, 3-21G, and 6-311G (when available). The properties calculated were the molecular geometry, vibrational frequencies, and dissociation energies. It was found that all the DFT-based methods, particularly when allied with the LANL2DZ basis set, produced results which are significantly closer to experimental values than those of the traditional Moller -Plesset (MP2) electron correlation method and which are also applicable to considerably larger molecules. Over the whole test set of molecules, the RMS errors of the four “BX” methods, in conjunction with LANL2DZ, were typically 3-4% for geometries, 6-8% for frequencies, and 10-16% for dissociation energies, with BPW91 and the popular B3LYP at the lower and upper ends of these ranges, respectively, and with the errors being overestimates and underestimates, respectively. The corresponding values for SVWN and MP2 were 2% and 6%, 12% and 12%, and 33% and 42%, with these errors typically being ( and +, + and -, and + and -, with + and - representing overestimates and underestimates, respectively. While the best bond lengths are produced by SVWN (a local spin density approximation), which is not uncommmon, this advantage over the gradient corrected (BX) methods is only slight, and the latter are markedly superior for frequencies and especially dissociation energies. Not supported by the present results are the notions that (all) pure DFT methods underestimate metal-ligand bond lengths and overestimate bond strengths and that hybrid methods are superior (and neither that DFT methods are overcorrelated). Testing on a subset of molecules with BPW91/ LANL2DZ revealed no benefit in supplementing this basis set by the addition of diffuse functions, nor of the counterpoise correction. There appear to be specific incompatibilities with some method/basis set combinations, and even the continuing availability of 3-21G for these metals is questionable. Because of its accuracy and reliability, the combination BPW91/LANL2DZ is recommended for these noble-metal systems (and to extensions such as the cluster-model approach to adsorption of a molecule on a metal surface).
Formation of Di‐isobutene, main by‐product of methyl tertiary butyl ethyl ether synthesis catalyzed by ion exchange resin

An experimental set-up is presented for the measurement of steady-state reaction rates in the liquid phase methyl tertiary butyl ether (MTBE) synthesis from isobutene and methanol using ion exchange resin as catalyst. This apparatus was used for a separate investigation of the main side reaction, i.e., the formation of isobutene dimers (DIB), in the temperature range between 60 and 90°C. The reaction catalyzed by Amberlyst 15 (A15) showed no steady-state behaviour, but the catalytic activity declined at a rate dependent on the reaction conditions. Time constants for activity loss were determined in the range from 3.5 to 30 h. The deactivated A15 catalyst could be regenerated through MTBE synthesis experiment. Deactivation is assumed to be caused by blocking of the microparticle gel phase by higher isobutene oligomers. The DIB formation, using 1-butene as solvent, was of 2nd order with respect to isobutene and showed an apparent activation energy of about 40 kJ/mol.
Afforestation effects on soil carbon stocks of low productivity grassland in New Zealand

Soil carbon stock change between two major land uses in New Zealand was measured by sampling paired plots across the boundaries of low productivity grassland and forest planted pre‐1990. The national soil carbon monitoring system uses low productivity grassland as a benchmark to evaluate soil carbon stock change for other land uses. The goal was to validate earlier estimates of the effect of pre‐1990 afforestation and to reduce their level of uncertainty. We selected a set of sites to represent the national stocks of forests planted pre‐1990. Previous studies derived estimates of the land‐use effect on soil carbon for afforestation ranging from +1.6 to −8.5 t/ha to 30 cm depth. For all estimates, the 95% confidence interval spanned zero. Our study used nine of the previous paired‐plot sites and sampled and analysed 21 new sites. The land‐use effect of change from grassland to forest planted pre‐1990 was estimated at −17.4 t/ha. The 95% confidence interval ranged from −10.1 to −24.6 t/ha and did not include zero change. The result supported the soil carbon monitoring system assumption that forests planted pre‐1990 have significantly lower soil carbon stocks than the low‐productivity‐grassland standard. Evidence of stock change occurred in depth increments to 0.2 m but with no significant change for the 0.2–0.3 m increment. This suggests that the sampling depth of 0.3 m was adequate for the estimation of soil carbon stock change.
The Role of Attractive and Repulsive Forces in the Formation of Tactoids, Thixotropic Gels, Protein Crystals and Coacervates

The formation of tactoids from thixotropic sols, of Schiller layers from iron‐oxide sols, the separation of tobacco virus solutions and bentonite sols into two liquid layers and the crystallization of proteins are regarded as examples of unipolar coacervation (micelles having like charges) which must involve attractive forces.Kallmann, Willstatter, Freundlich, De Boer, Hamaker, Houwink and others have assumed that the attraction is due to van der Waals forces. They have also analyzed the stability of colloid systems by diagrams giving the potential energy as a function of the distance between micelles. It is now shown that the Coulomb attraction between the micelles and the oppositely charged ions in the solution gives an excess of attractive force which must be balanced by the dispersive action of thermal agitation and another repulsive force. Thus there is no need to assume long range van der Waals forces. The past use of energy diagrams is criticized because it has ignored the effect of the thermal agi.
Chiral (η6-p-Cymene)ruthenium(II) Complexes Containing Monodentate Acylthiourea Ligands for Efficient Asymmetric Transfer Hydrogenation of Ketones

The new chiral ligands (R)-/(S)-N-((1-phenylethyl)carbamothioyl)benzamide (L1/L2), (R)-/(S)-N-((1-phenylethyl)carbamothioyl)thiophene-2-carboxamide (L3/L4), and (R)-/(S)-N-((1-phenylethyl)carbamothioyl)furan-2-carboxamide (L5/L6) were synthesized, characterized, and used to prepare novel chiral Ru(II) complexes. The chiral Ru(II) complexes 1–6 were obtained from reactions between the chiral ligands L1–L6 and [RuCl2(p-cymene)2]2. The complexes were characterized by analytical and spectroscopic (NMR, FT-IR, electronic) techniques. The solid-state structures of the ligands L1 and L3 and complexes 1, 4, and 6 were determined by single-crystal X-ray diffraction methods. In all of the complexes, the ligand is bound to the Ru(II) center only via the sulfur donor atom. This monodentate coordination of the acylthiourea ligands was observed for the first time with ruthenium. The Ru(II) complexes 1–6 all act as efficient catalysts for the asymmetric transfer hydrogenation of aromatic ketones in the presence of 2-pro.
Neue Wärmeleitfähigkeitsmessungen an organischen Flüssigkeiten

Zur endgultigen Klarung der grosen Widerspruche zwischen den Mesergebnissen verschiedener Autoren fur die Warmeleitfahigkeit organischer Flussigkeiten wurden neue Absolutmessungen mit einer Kugelapparatur durchgefuhrt, die innerhalb der Mesgenauigkeit von etwa 1% zu einer Bestatigung der vom Verfasser fruher mit anderen Apparaturen gefundenen Werte fuhrten. Neue Messungen zwischen −80 und +80 °C fur eine grosere Anzahl von Flussigkeiten ermoglichen, zusammen mit zuverlassigen Literaturwerten, im Sinne des Theorems der ubereinstimmenden Zustande eine ubersichtliche Darstellung der Abhangigkeit der Warmeleitfahigkeit nicht assoziierter Flussigkeiten von der reduzierten Temperatur.
Feasibility of palm‐biodiesel fuel for a direct internal reforming solid oxide fuel cell

The feasibility of a direct internal reforming (DIR) solid oxide fuel cell (SOFC) running on wet palm‐biodiesel fuel (BDF) was demonstrated. Simultaneous production of H2‐rich syngas and electricity from BDF could be achieved. A power density of 0.32 W cm−2 was obtained at 0.4 A cm−2 and 800 °C under steam to carbon ratio of 3.5. Subsequent durability testing revealed that a DIR‐SOFC running on wet palm‐BDF exhibited a stable voltage of around 0.8 V at 0.2 A cm−2 for more than 1 month with a degradation rate of approximately 15 % / 1000 h. The main cause of the degradation was an increase in the ohmic resistance. Copyright © 2012 John Wiley & Sons, Ltd.