Miracle-dz/UniFAR-FTUs huggingface dataset:
Photocrosslinked poly(anhydrides) for spinal fusion: characterization and controlled release studies.

In the past decade, injectable biomaterials that are capable of in situ formation have garnered increased interest for use in restorative orthopedic procedures. In this study, the in vitro degradation of photocrosslinked polyanhydride matrices, derived from methacrylic anhydrides of 1,6-bis(p-carboxyphenoxy)hexane (MCPH) and sebacic acid (MSA) were evaluated over a six-week period under physiological conditions. These matrices were augmented with two additives – the reactive diluent polyethylene glycol diacrylate (PEGDA) and the buffering agent calcium carbonate (CaCO3). Disc shaped specimens were produced by crosslinking the components using both chemical and photoinitiators and exposure to visible light. The experimental variables studied included: MCPH:MSA ratio, PEGDA molecular weight and weight fraction, and incorporation of CaCO3. The effects of these variables on local pH, water uptake, mass loss, and mechanical properties were explored. Increasing the MCPH:MSA ratio decreased the mass loss and water uptake at predetermined endpoints, and decreased buffer acidity during degradation. Both PEGDA and CaCO3 were found to decrease acidity and to reduce water uptake during degradation. Incorporation of CaCO3 enabled maintenance of compressive modulus during degradation. These results demonstrate that incorporation of reactive diluents and nonreactive additives into networks of photocrosslinked anhydrides can improve system properties as a material for bone replacement.
Liquid−Liquid Phase Transition of Mixtures Comprising Squalene, Olive Oil, and Ethyl Lactate: Application to Recover Squalene from Oil Deodorizer Distillates

Experimental and modeling studies of the liquid−liquid equilibria at ambient pressure of three model systems—squalene + ethyl lactate, olive oil + ethyl lactate, and squalene + olive oil + ethyl lactate—were performed with the view to explore the potential application of an agrochemical solvent, namely, ethyl lactate, to recover squalene from pretreated olive oil deodorizer distillate. The favorable separation factors obtained reveal the strength and potential of ethyl lactate as a green solvent for the recovery of squalene from squalene + triglyceride mixtures.
High-pressure recrystallisation—a route to new polymorphs and solvates

The recrystallisation of organic compounds from solution under high-pressure conditions is shown to be a versatile method for the formation of new polymorphs and solvates. The technique is illustrated by the crystallisation of a new polymorph of phenanthrene from dichloromethane at a pressure of 0.7 GPa, and the crystallisation of a novel dihydrate of paracetamol from water at a pressure of 1.1 GPa. These phases have been characterised by single crystal X-ray diffraction. We also demonstrate that the technique can be used to prepare a polymorph that is metastable under ambient conditions. Thus the orthorhombic form of paracetamol was crystallised from ethanol at a pressure of 1.1 GPa.
The effect of a branched architecture on the antimicrobial activity of poly(sulfone amines) and poly(sulfone amine)/silver nanocomposites

The antimicrobial activity of a series of cationic poly(sulfone amines) (PSAs) with different branched architectures and their polymer/silver (PSA/Ag) nanocomposites was investigated. PSAs with different branched architectures were synthesized through the polycondensation–addition reaction of divinylsulfone and 1-(2-aminoethyl)piperazine in mixed solvents. The silver ions were complexed to PSAs and then reduced to form PSA/Ag nanocomposites. The size of the silver nanoparticles (AgNPs) decreased with an increasing polymeric branched architecture. Both PSAs and PSA/Ag nanocomposites exhibited antimicrobial activity. Interestingly, the influence of the branched architecture on the antimicrobial activity was quite different for PSAs and PSA/Ag nanocomposites. For PSAs, the antimicrobial activity decreased with the branched architecture due to the reduced zeta-potential and low toxicity of the branched polymers. Owing to the high specific surface of small AgNPs, PSA/Ag nanocomposites exhibited an enhanced antimicrobial activity with an increasing polymeric branched architecture. These results demonstrate that the branched architecture of PSAs has an obvious influence on the antimicrobial activity of PSAs and PSA/Ag nanocomposites.
Hydrogen Storage in Activated Carbons and Activated Carbon Fibers

Hydrogen storage has been studied in a large variety of activated carbons and activated carbon fibers and a wide range of pressures (up to 70 MPa). The experimental technique used has good reliability, and the experiments performed have a small error and high reproducibility. This seems to be essential to get trustworthy conclusions. In these samples, we have not found large amounts of hydrogen adsorbed. In any case, an activated carbon derived through a simple preparation method provides hydrogen storage values at 10 MPa close to 1 wt % (i.e., a value close to the target from an application point of view). The experimental results have been compared with theoretical work found in the literature, and an important agreement can be observed. From this study, we conclude that the optimum pore size for hydrogen storage is that which can hold two layers of adsorbed hydrogen. This work also considers practical aspects related to hydrogen storage in activated carbons and activated carbon fibers.
Change in the Dehydration and Crystallization Processes of V2O5 Xerogel due to Mechanical Pretreatment

Abstract Dehydration and crystallization processes of vanadium pentoxide xerogels, V2O5 · 1.6H2O, with and without preliminary mechanical pretreatment, were examined by thermal and structural analyses. During the final step of dehydration of as-prepared xerogel, crystallization into orthorhombic V2O5 took place slowly but in one step, with a certain period of coexistence of the starting layer structure. The mechanically pretreated xerogel, in contrast, crystallized itself in two steps with a separated nucleation and growth, and allowed a smaller period of coexistence with the layer structure. These phenomena are associated with the disproportionation of the bonding state of interfoliar H2O.
Synthesis of N,N-phthaloyl-L-valine and N,N-phthaloyl-L-isoleucine with N-(ethoxycarbonyl)phthalimide

The synthesis of N,N-phthaloyl-L-valine and N,N-phthaloyl-L-isoleucine with N-(ethoxycarbonyl)phthalimide, using a modification of the method of Nefkens, Tesser and Nivard, is described. When aqueous solutions of the sodium salts of the amino acids are stirred at room temperature with a 10% excess of N-(ethoxycarbonyl)phthalimide, dissolved in ethyl acetate, the main products formed are N-[N-(ethoxycarbonyl)phthalamoyl]-L-valine or N-[N-(ethoxycarbonyl)phthalamoyl]-L-isoleucine. The presence of these intermediates confirms the reaction mechanism proposed by Nefkens et al. Refluxing these compounds in toluene gives good yields of optically pure phthaloyl-L-valine and phthaloyl-L-isoleucine. From the synthesis of phthaloylvaline, N-(ethoxycarbonyl)phthalamic acid and minor amounts of phthalic acid, valine and the phthalamic acid derivative from phthaloylvaline were identified as by-products.
Effect of electron donors on 1,3‐butadiene polymerization by a Ziegler–Natta catalyst based on neodymium

High-cis polybutadiene produced by catalyst systems based on a rare earth is an elastomer used to produce green tires. This type of tire presents lower rolling resistance, which allows higher fuel economy, and thus fewer chemical compounds are discharged into the atmosphere. In this work, the influence of electron donors [tetrahydrofuran (THF) and tetramethylethylenediamine (TMEDA)] present in the polymerization solvent on the microstructure and molecular weight characteristics of the polybutadiene produced by neodymium catalysts was studied. The catalyst synthesis was carried out in glass bottles for 1 h at a temperature between 5 and 10°C. The catalyst components were diisobutylaluminum hydride, neodymium versatate, and tert-butyl chloride. The polymerization reaction was carried out for 2 h. The reaction temperature was kept at 70± 3°C. The addition of TMEDA or THF above a determined concentration reduced the catalytic activity, molecular weight, and concentration of cis-1,4 units (<96%), whereas the polydispersity increased. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2539–2543, 2005
Influence of land use (savanna, pasture, Eucalyptus plantations) on soil carbon and nitrogen stocks in Brazil

In Brazil, most Eucalyptus stands have been planted on Cerrado (shrubby savanna) or on Cerrado converted into pasture. Case studies are needed to assess the effect of such land use changes on soil fertility and C sequestration. In this study, the influence of Cerrado land development (pasture and Eucalyptus plantations) on soil organic carbon (SOC) and nitrogen (SON) stocks were quantified in southern Brazil. Two contrasted silvicultural practices were also compared: 60 years of short‐rotation silviculture (EUCSR) versus 60 years of continuous growth (EUCHF). C and N soil concentrations and bulk densities were measured and modelled for each vegetation type, and SOC and SON stocks were calculated down to a depth of 1 m by a continuous function.
Epoxidation of olefins with molecular oxygen as the oxidant using gold catalysts supported on polyoxometalates

We report a highly efficient green process for the epoxidation of various olefins using polyoxometalate-supported gold nanoparticles as catalysts and using oxygen as the terminal oxidant. The nanoparticles were prepared through thermal reduction of Au(III) and were characterised by TEM and XPS. The elemental composition of the catalyst was also determined using ICP. The results show that higher calcination temperatures give a higher degree of reduction, but also result in some sintering of the particles. The catalytic epoxidation reaction may be carried out with or without a solvent and with air or molecular oxygen as the stoichiometric oxidant and using t-butyl hydroperoxide as an initiator. The method shows consistently high conversions and >90% selectivity to epoxide formation for norbornene and cyclooctene oxidation. The catalysts show little deactivation with time and are easily recovered by filtration and can be reused with little or no loss in activity and selectivity.
Photoinduced liquid crystal blue phase by bent-shaped cis isomer of the azobenzene doped in chiral nematic liquid crystal

A photoresponsive azobenzene molecule DCAZO2 with two cholesteryl groups linked to both sides of the azobenzene group is doped in a mixture of nematic liquid crystal E7 and chiral dopant S811 (61.9 wt% E7, 36.1 wt% S811 and 2.0 wt% DCAZO2). Cooled from isotropic phase to 33.0°C, chiral nematic liquid crystal (N*LC) was formed in the sample and then the temperature was kept unchanged at 33.0°C. UV light irradiation induces the trans–cis photoisomerisation and thus an obvious phase transition. When the azobenzene groups isomerise to a cis-saturated state, the UV light was turned off and the white light was turned on at the same time. The bent-shaped cis isomer then turns back to the planar trans isomer gradually. A blue–green platelet texture representing cubic blue phase (BP) was observed and the size of the platelets was increased along with the cis–trans isomerisation. UV–vis absorption spectra indicate that the photoinduced BP exists when the isomerisation degree is between 79% and 18%, and further cis–trans isomerisation change BP back into N*LC. The large geometric structure of the cholesteryl groups and the large bent angle θ of the cis isomer are supposed to be responsible for the interesting result.
Modeling charge transport in conjugated polymers

Previously, we presented a model for ion transport in conjugated polymers during electrochemical reduction. In this paper, we will present a more advanced model that includes hole transport, which was neglected in the first-cut model. This addition takes into account the interactions between holes and cations during transport. The result is that the front between oxidized and reduced material now propagates with constant velocity, instead of slowing down over time. Also, an electrolyte layer has been added to the model, and as a result the ion concentration behind the phase front is more accurately predicted.
Syntheses of Two Dopo-Based Reactive Additives as Flame Retardants and Co-Curing Agents for Epoxy Resins

GRAPHICAL ABSTRACT Abstract Two novel phosphorus-nitrogen-containing flame retardants, 1,1′,2,2′-tetra-hydroxyl-4′′, 4′′′-biphenylene-bis[amino-((10′′′′-O-10′′′′-H-9′′′′-oxa-10′′′′λ5-phosphaphenanthrene-10′′′′-yl))-methyl]}-bisphenol (3) and 1,1′,2,2′-tetra-hydroxyl-{4′′,4′′′-phenylene-bis[amino-((10′′′′- O-10′′′′- H-9′′′′- oxa-10′′′′λ5-phosphaphenanthrene-10′′′′-yl))-methyl]}-bis-phenol (4) were synthesized by two steps: 1,1′,2,2′-tetra-hydroxyl-{4′′,4′′′- bi-phenylene-bis[amino-methyl]}-bis-phenol, imine (1), was synthesized through condensation reaction between 3,4-dihydroxybenzaldehyde and 4,4′-diaminobiphenyl; and, 1,1′,2,2′-tetra-hydroxyl-{4′′,4′′′- phenylene-bis[amino-methyl]}-bis-phenol, imine (2) was synthesized by the reaction of 3,4-dihydroxybenzaldehyde and 1,4-phenylenediamine; then, addition reactions between 9,10-dihydro-9-oxa-10- phosphaphenanthrene-10-oxide and the two imines, the (3) and (4) were obtained, respectively. (1)–(4) were characterized by FTIR, NMR, and MS. (3) and (4) reacted with epoxy resins as co-curing agents with 4,4′-diaminodiphenylmethane. Compared with control samples, (3) or (4) co-cured epoxy thermosets with phosphorus content of 1.0 wt% possessed good flame retardant properties with LOI value reaching more than 36.0, higher char yields. The glass translation temperature (Tg) of thermosets containing (3) or (4) were characterized with suitable changes by DSC test.
Application of Methods for the Detoxification and Neutralization of Formalin in Fish Hatchery Effluents

Abstract Sodium sulfite, Neutralex, hydrogen peroxide, and hydrogen peroxide with a ferric iron catalyst were studied for potential application in reducing formalin in effluents from aquaculture facilities. The neutralization capacity of each method was examined at formalin concentrations that are typically found in effluents from fish hatcheries that utilize formalin to control ectoparasite infestations on fish. The toxicities of the products were also evaluated. A 75% reduction in formalin concentration was observed within the first 10 min after the addition of sodium sulfite at a 3:1 (sodium sulfite : formalin) mass treatment ratio. The addition of Neutralex to test solutions at a 6:1 (Neutralex : formalin) mass treatment ratio reduced the formalin concentration by approximately 90% of initial values within 10 min and completely eliminated formalin within 20 min. Degradation of formalin was not successful under the test conditions using hydrogen peroxide alone or in combination with a ferric iron catal.
The Role of Biomass in Greenhouse Gas Mitigation

Abstract Biomass can play a dual role in greenhouse gas mitigation related to the objectives of the UNFCCC, i.e., as an energy source to substitute for fossil fuels and as a carbon store. However, compared to the maintenance and enhancement of carbon sinks and reservoirs, it appears that the use of biomass has so far received less attention as a means of mitigating climate change. Modern biomass options offer significant, cost-effective and perpetual opportunities toward meeting emission reduction targets while providing additional ancillary benefits. Moreover, via the sustainable use of the accumulated carbon, biomass has the potential for resolving some of the critical issues surrounding long-term maintenance of biotic carbon stocks. In the case of Turkey, energy consumption and environmental pollution are increasing rapidly due to its economic growth. As for the energy consumption, in parallel to the demand for heat and electricity, greenhouse gas emissions (GHGs) from energy use increase accordingly. In this regard, biomass and other renewables are becoming an attractive solution to the GHG mitigation for Turkey and other countries throughout the world. Finally, wood products can act as substitutes for more energy-intensive products, can constitute carbon sinks, and can be used as biofuels at the end of their lifetime.
Effects of hydrogen plasma treatment on the structural and electrical properties of sputter-deposited SnO2 thin films

In this paper, we report the effects of hydrogen plasma treatment on the structural and electrical properties of SnO2 thin films prepared by the sputtering method. Whereas the hydrogen plasma treatment led to etching of SnO2 films and subsequent degradation of crystalline quality and optical transmittance, the plasma-treated films exhibited an improvement in the electrical conductivity. Hall measurements indicated an increase in the carrier concentration of SnO2 films which, following x-ray diffraction and secondary ion mass spectrometry measurements, was attributed to the generation of oxygen vacancies rather than the incorporation of hydrogen shallow donors in undoped SnO2 films.
Theoretical studies of the spin-Hamiltonian parameters and defect structure for the tetragonal Gd3+ center in cubic c-RbZnF3 crystal

A diagonalization (of the energy matrix for which the Hamiltonian contains the free ion, crystal-field interaction and Zeeman interaction terms) method was applied to calculate the spin-Hamiltonian parameters (g factors, g // and , and five zero-field splittings, ) for the tetragonal Gd3+ center in cubic c-RbZnF3 perovskite. The calculated results are in reasonable agreement with experimental values. From the calculation, the defect model that the tetragonal Gd3+ center is attributed to Gd3+ occupying the 12-fold coordinated Rb+ site associated with a nearest Rb+ vacancy, VRb, along C 4 axis owing to charge compensation is confirmed and the defect structural data of this Gd3+ impurity center in c-RbZnF3 are acquired. The results are discussed.
High Temperature Oxidation Studies Of Binary And Ternary Iron Based Alloys At 700°C

The high temperature oxidation of iron-based alloys is a crucial factor in limiting the lifetime of core components operating under extreme thermal conditions. To understand their oxidation mechanisms on a fundamental level, kinetic studies of oxidation were performed within this study. For this, a newly developed high temperature corrosion test (HT-CT) was utilised to oxidise different materials at temperatures up to 700°C. Several binary and ternary iron-based alloys were selected for investigating the influence of alloying elements: Fe-Cr, Fe-Ni, Fe-Al, Fe-Cr-Ni. Fundamental investigations of the scale formation including detailed scanning electron microscopic surface and cross sectional analyses were performed on the specimens. The chemical compositions of the formed scales were revealed by using X-ray diffraction analyses. Regression analysis with regard to the oxidational time constant and the square law of oxidation was performed. Statistical evaluations were performed to quantitatively evaluate the different influences on the oxidation behaviour of iron based alloys. The focus of this study is the disclosure of different oxidation mechanisms on the tested model alloys. The influence of individual alloying elements and their interdependence on the oxidation behaviour is presented. The results indicate a high relevance of the alloying elements in iron based alloys on the oxidational stability and can be ranked as Ni << Cr < Al. This ranking can be justified according to diffusion coefficients and the standard formation enthalpy of the oxides and their influence on the formation of oxide layers, which can be statistically compared to the oxidational stability of different model alloys presented within this study.
Conséquences des traitements technologiques sur la qualité de la viande

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Conséquences des traitements technologiques sur la qualité de la viande A. Ouali
Phase separation and crystallization of La2O3 doped ZnO- B2O3-SiO2 glass

In order to investigate the effect of the La2O3 on the phase separation and crystallization of ZnO-B2O3-SiO2 glass, after occur of the phase separation and crystallization of glasses by heat treatment, the microstructure morphology and distribution of elements in the different sample areas were characterized by the scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS); the non-isothermal crystallization kinetics of the glass samples was studied by using a differential scanning calorimeter (DSC) and the precipitated crystals of crystallized glass were determined by the X-ray diffraction (XRD). The results suggest that the phase separation and crystallization of 60ZnO-30B2O3-10SiO2 glass are occurred at glass surface, and the incorporation of small amount (< 4 mol%) of La2O3 significantly inhibits the glass phase separation and consequently improves the thermal stability of glass. Doping of La2O3 accelerates the glass crystallization at the elevate temperature (660°C), making the depth of crystal layer thicker and diffraction intensity in XRD patterns stronger. However, due to the precipitation of several crystals occur simultaneously when La2O3 doping amount is 4mol%, crystallization of the 60ZnO-30B2O3-10SiO2 glass is obviously depressed, the crystallization activation energy Ec and the relative crystallinity Xc of the glass reaches the maximum and the minimum values respectively. Although transition from one-dimensional growth of crystals to twodimensional growth of crystals results from La2O3 addition, the one-dimensional growth of crystals remains dominant in crystallization process. This work can provide some useful information for preparing glass ceramics with nanocrystals precipitated in the glass surface.
Binding of pyrene to aquatic and commercial humic substances: The role of molecular weight and aromaticity

The binding of pyrene to a number of humic substances isolated from various aquatic sources and a commercial humic acid was measured using the solubility enhancement method. The humic materials used in this study were characterized by various spectroscopic and liquid chroma tography methods. A strong correlation was observed between the pyrene binding coefficient, Kdoc, and the molecular weights, molar absorptivities at 280 nm, and aromaticity of the aquatic humic substances. Binding of pyrene to the commercial humic acid, however, was significantly stronger and did not obey the relationships observed between Kdoc and the chemical properties of the aquatic humic substrates. These results suggest that the molecular weight and the aromatic content of the humic substrates exert influences on the binding of nonpolar and planar aromatic molecules and that the physicochemical properties of both humic materials and organic solutes are important in controlling the speciation of nonpolar organic contaminants in na.