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This work examines the oil-binding behavior of cosmetic paraffin wax-mineral oil systems using powder X-ray diffraction (XRD), differential scanning calorimetry (DSC), and pulsed nuclear magnetic resonance (pNMR). Neat paraffin wax crystals and paraffin wax oleogels crystallized into the same polymorphic forms; however, the oleogels had a larger lamellar thickness and crystal domain size. This increase in lamellar size could indicate that the oil was structured in between individual wax crystalline lamellae (i.e., nanostructured oil). The amount of crystalline material determined by pNMR of wax oleogels increased with temperature below their melting point, because interlamellar nanostructured oil lost some mobility and displayed solid-like behavior. These results provide experimental evidence for the existence of nanostructured oil, in support of simulation studies in the literature, and shed light into the oil-binding mechanism of some materials. [ABSTRACT FROM AUTHOR]

Stable dispersions of paraffin wax droplets and their nano- and microspheres have broad applications. Despite intensive efforts, the production of uniform wax spheres remains a challenge. For their preparation, abundant surfactants and other additives are commonly used to stabilize the dispersions. These additives are hardly removable and entrain often adverse consequence in many applications, particularly in biological and medical applications, where microspheres with absolutely clean surface are preferred. We report here a novel process to prepare stable dispersion of wax droplets in a water-ethanol mixture with a narrow size distribution by simply shaking without any surfactants. The process is featured by using primary polymer particles (PPs) of poly(dodecene-trihydroxymethylpropane triacrylate) as a Pickering stabilizer. PPs were prepared by precipitation polymerization without any surfactant and stabilizer. By rapidly cooling the wax emulsion, solid wax spheres with good uniformity were obtained. Their size, between 50 and 480 μm, was easily adjustable by changing the shaking rate, number of PPs, and particularly the size of PPs. The morphology of the wax spheres was examined by SEM, which showed that they were covered by a layer of PPs. The formation mechanism of the microspheres was also discussed on the basis of the adsorption energy of PPs on wax spheres, estimated from the corresponding contact angle of the solvent toward the PPs and the wax. This paper presents a novel pathway for the preparation of wax microspheres with only polymer particles without the need for any other additives. [ABSTRACT FROM AUTHOR]

A novel palladium-catalyzed amination and nitration of ethyl vinyl ether for the construction of β-nitroamine derivatives under mild conditions has been developed. This transformation provides a new strategy for the installation of amino and nitro from aromatic amines and nitro-paraffin into alkenes. Morpholine resulted in the aza-Henry reaction, while DABCO led to the unexpected rearrangement. [ABSTRACT FROM AUTHOR]

An experimental study was performed to investigate the liquid granulation process on the rotary disks. Four groups of rotary disks were specially designed, and rosin/paraffin mixture was used as the working fluid. At first, the nondimensional transition equations between different breakup modes were obtained. Then, comparative analyses were performed to characterize the critical transition characteristics. Higher Q+ values for bulged-block disk from direct drop to ligament and ligament to fully ligament were observed, while the first appearance of the sheet mode nearly coincided for all types of disks. Finally the transition maps were proposed, and the effects of operational conditions and liquid properties on transition characteristics were analyzed. The transition maps showed that the broadest transition area from ligament to sheet mode was indentified in arc-edge disk, while the narrowest area appeared in bulged-block disk. Moreover, the transition between different modes was promoted by decreasing Q and ω or increasing μ. [ABSTRACT FROM AUTHOR]

This work proposes a new development in the use of melted paraffin wax as a new extractant in a procedure designed to aggregate the advantages of liquid phase extraction (extract homogeneity, fast, and efficient transfer, low cost and simplicity) to solid phase extraction. As proof of concept, copper(II) in aqueous samples was converted into a hydrophobic complex of copper(II) diethyldithiocarbamate and subsequently extracted into paraffin wax. Parameters which affect the complexation and extraction (pH, DDTC, and Triton X-100 concentration, vortex agitation time and complexation time) were optimized in a univariate way. The combination of the extraction proposed procedure with laser-induced breakdown spectroscopy allowed the precise copper determination (coefficient of variation = 3.1%, n = 10) and enhanced detectability because of the concentration factor of 18 times. A calibration curve was obtained with a linear range of 0.50-10.00 mg L-1 (R2 = 0.9990, n = 7), LOD = 0.12 mg L-1, and LOQ = 0.38 mg L-1 under optimized conditions. An extraction procedure efficiency of 94% was obtained. The accuracy of the method was confirmed through the analysis of a reference material of human blood serum, by the spike and recovery trials with seawater, tap water, mineral water, and alcoholic beverages and by comparing with those results obtained by graphite furnace atomic absorption spectrometry. [ABSTRACT FROM AUTHOR]

The catalyst is crucial in Fischer-Tropsch synthesis (FTS). The activity and selectivity of the FT products could be affected during deactivation. The variation of the formation rate and selectivity to the light olefin and paraffin products with time on stream (TOS) over a cobalt catalyst has been investigated using a fixed bed reactor. The catalyst deactivated during the experiments, with the CO conversion dropping from 46.1% at 110 h TOS to 12.8% at 1200 h TOS. The selectivity to olefins increased with a drop in the CO conversion, whereas the selectivity to paraffin did not change much. A comparison of the rates before, during, and after deactivation showed that the olefin formation rate was fairly constant, and in some cases even increased, while the paraffin formation rate dropped, indicating that the deactivation affects mainly the paraffin formation rate. The results imply that when designing or operating a cobalt-based FTS process, the formation rates of olefin and paraffin should be considered separately. [ABSTRACT FROM AUTHOR]

The predictions of the crystallization temperature and the amount of precipitates of paraffin waxes at high pressure conditions may be inaccurate using existing thermodynamic models. This is mainly due to the lack of experimental data on the molar volume of solid paraffins at high pressures. This inaccuracy is even more pronounced for mixtures of high asymmetry. The present work provides a new accurate modeling approach for solid-fluid equilibrium (SFE) at high pressure conditions, more specifically, for highly asymmetric systems. In contrast to the conventional methods for high pressure SFE modeling which define a Poynting molar volume correction term to calculate the paraffin solid phase nonideality at high pressures, the new method exploits the values of thermophysical properties of importance in SFE modeling (temperatures and enthalpies of fusion and solid-solid transition) evaluated at the high pressure condition using a new insight into the well-known Clausius-Clapeyron equation. These modified parameters are then used for evaluation of the fugacity in the solid phase at higher pressure using the fugacity of pure liquid at the same pressure and applying the well-established formulation of the Gibbs energy change during melting. Therefore, the devised approach does not require a Poynting correction term. The devised approach coupled with the well-tested UNIQUAC activity coefficient model is used to describe the nonideality of the solid phase. For the fluid phases, the fugacities are obtained with the SRK EoS with binary interaction parameters calculated with a group contribution scheme. The model is applied to highly asymmetric systems with SFE experimental data over a wide range of pressures. It is first used to predict crystallization temperature in binary systems at high pressures and then verified by applying it on multicomponent mixtures resembling intermediate oil and natural gas condensates. [ABSTRACT FROM AUTHOR]

On-tissue digestion matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) can be used to record spatially correlated molecular information from formalin-fixed, paraffin-embedded (FFPE) tissue sections. In this work, we present the in situ multimodal analysis of N-linked glycans and proteins from the same FFPE tissue section. The robustness and applicability of the method are demonstrated for several tumors, including epithelial and mesenchymal tumor types. Major analytical aspects, such as lateral diffusion of the analyte molecules and differences in measurement sensitivity due to the additional sample preparation methods, have been investigated for both N-glycans and proteolytic peptides. By combining the MSI approach with extract analysis, we were also able to assess which mass spectral peaks generated by MALDI-MSI could be assigned to unique N-glycan and peptide identities. [ABSTRACT FROM AUTHOR]

We developed a model of paraffin wax crystal coarsening that well describes our experimental results and allows the behavior of the paraffin films to be predicted on the basis of the extracted kinetic parameters. Wax crystalline films were evaporated on different substrates (silicon wafer, glass slide, thin layer of gold on silicon), thermally treated at different temperatures (25-60 °C), and investigated by powder X-ray diffraction, high-resolution scanning electron microscopy, and optical confocal imaging of the surfaces. A preferred (110) crystal orientation of all deposited wax films, independent of substrate type, was observed from the start and increased during heat treatment. The change in preferred orientation was accompanied by changes in crystal morphology and shape, resulting in surface nanoroughening. We modeled the process as the coarsening of oriented C36H74 crystal islands driven by the decrease in total surface energy. Coarsening kinetics was controlled by diffusion of single molecular chains along the substrate. Evolution of nanoroughness during annealing time was well described by a surface coarsening law, Hr ~ t1/4. Two additional factors influenced the evolution rate: strains accumulated in wax crystals during deposition, and the initial crystal shape diverged from the shape at equilibrium. Both factors lowered activation energy and effectively shortened coarsening time. [ABSTRACT FROM AUTHOR]

Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging is a rapidly evolving field in which mass spectrometry techniques are applied directly on tissues to characterize the spatial distribution of various molecules such as lipids, protein/peptides, and recently also N-glycans. Glycans are involved in many biological processes and several glycan changes have been associated with different kinds of cancer, making them an interesting target group to study. An important analytical challenge for the study of glycans by MALDI mass spectrometry is the labile character of sialic acid groups which are prone to in-source/postsource decay, thereby biasing the recorded glycan profile. We therefore developed a linkage-specific sialic add derivatization by dimethylamidation and subsequent amidation and transferred this onto formalin-fixed paraffin-embedded (FFPE) tissues for MALDI imaging of N-glycans. Our results show (i) the successful stabilization of sialic adds in a linkage spedfic manner, thereby not only increasing the detection range, but also adding biological meaning, (ii) that no noticeable lateral diffusion is induced during to sample preparation, (iii) the potential of mass spectrometry imaging to spatially characterize the N-glycan expression within heterogeneous tissues. [ABSTRACT FROM AUTHOR]

We report on HistoMosaic, a novel technique for genetic analysis of formalin-fixed, paraffin-embedded tissue slices. It combines microfluidic compartmentalization, in situ allele-specific PCR, and fluorescence microscopy. The experimental proof of principle was achieved by in situ detection of KRAS G12V mutation in colorectal cancer tissues and is presented herein. HistoMosaic offers the ability to detect mutations over the entire tissue slide simultaneously, rapidly, economically, and without selection bias, while coregistering the genetic information with the preserved morphological information. Thus, HistoMosaic has wide applicability in basic science as a tool to map genetic heterogeneity. It is also a platform to build companion diagnostics for targeted therapies in oncology, to help ensure that the right drug is given to the right patient, thereby saving healthcare resources and improving patient outcomes. [ABSTRACT FROM AUTHOR]

A multimodal mass spectrometry imaging (MSI) based approach was used to characterize the molecular content of crystal-like structures in a frozen and paraffin embedded piece of a formalin-fixed rabbit kidney. Matrix assisted laser desorption/ionization time-of-flight (MALDI-TOF) imaging and desorption electrospray ionization (DESI) mass spectrometry imaging were combined to analyze the frozen and paraffin embedded sample without further preparation steps to remove the paraffin. The investigated rabbit kidney was part of a study on a drug compound in development, in which severe renal toxicity was observed in dosed rabbits. Histological examination of the kidney showed tubular degeneration with precipitation of crystal-like structures in the cortex, which were assumed to cause the renal toxicity. The MS imaging approach was used to find out whether the crystal-like structures were composed of the drug compound, metabolites, or an endogenous compound as a reaction to the drug administration. The generated MALDI-MSI data were analyzed using principal component analysis. In combination with the MS/MS results, this way of data processing demonstrates that the crystal structures were mainly composed of metabolites and relatively little parent drug. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The analysis of crude oil and its fractions by applying ambient ionization techniques remains underexplored in mass spectrometry (MS). Direct analysis in real time (DART) in the positive-ion mode was coupled to a linear quadrupole ion trap Orbitrap mass spectrometer (LTQ Orbitrap) to analyze crude oil, paraffin samples, and porphyrin standard compounds. The ionization parameters of DART-MS were optimized for crude oil analysis. DART-MS rendered the optimum conditions of the operation using paper as the substrate, T = 400°C, helium as the carrier gas, and a sample concentration ≥6 mg mL. In the crude oils analysis, the DART(+)-Orbitrap mass spectra detected the typical N, NO, and O-containing compounds. In the paraffin samples, oxidized hydrocarbon species (O classes, where x = 1-4) with double-bond equivalent of 1-4 were detected, and their structures and connectivity were confirmed by collision-induced dissociation (CID) experiments. DART(+)-MS has identified the porphyrin standard compounds as [M + H] ions of m/ z 615.2502 and 680.1763, where M = CHN and CHNOV, respectively, based on the formula assignment and by phenyl losses observed on CID experiments. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Thermo-capillarymigration is a phenomenon in which surface thermalgradients drive a liquid to flow from warm to cold regions withoutexternal forces. It is important to prevent the migration of liquidlubricants on rubbing surfaces. In this paper, a pattern of microdimpleswas proposed to obstruct the liquid migration induced by an omnidirectionalthermal gradient. Microdimple patterns were fabricated on the surfacesof SUS316 stainless steel. Experiments were performed to investigatethe influence of microdimple patterns with different geometric parameterson the migration behavior of paraffin oil. In particular, this studyfocused on the interfacial flowing near the microdimples. The resultsdemonstrated that microdimples have a significant obstructive effecton migration, whereas dimples have a retaining effect, and the adjacentdimples have an interacting effect. [ABSTRACT FROM AUTHOR]

Modificationof the paraffin crystallization and flow ability ofwaxy crude oil is of vital importance during transportation and restartprocesses at low temperature. To investigate the influence of pendantsin comb-type copolymers on the cold flow ability of crude oil, maleicanhydride-α-octadecene copolymer and its derivatives with octadecyl(MAC), phenyl (AMAC), or naphthalene (NMAC) pendants were synthesized.These derivatives, when added to waxy crude oil, change the size andquantity of the paraffin crystals observed by polarizing light microscopy(PLM), improve the flow ability of waxy oils by reducing the viscosityand yield stress revealed by rheometer, and decrease the paraffincrystallization temperature and quantity of wax precipitation determinedby differential scanning calorimetry (DSC). AMAC had the greatesteffect followed by MAC and NMAC, respectively. It seems that smallaromatic pendants improve the flow ability of waxy oils by adsorbingon the surface of asphaltenes, while large aromatic pendants impairthe assembly of copolymers with asphaltenes by a higher steric hindrance. [ABSTRACT FROM AUTHOR]

Theinterfacial tension (IFT) of a crude oil/CO2systemis recognized as the main property affecting the efficiency of CO2flooding during an enhanced oil recovery (EOR) process. Theaddition of a paraffin group hydrocarbon to asphaltenic crude oilsas an asphaltene precipitant component is aimed to mimic the asphalteneprecipitation process during crude oil production and transportation.Asphaltene precipitation would critically affect the interfacial behaviorof crude oil/CO2systems. In the first part of this study,the equilibrium densities of oil samples which contain n-heptane at different ratios were measured over varying pressuresat 323 K. Then, the equilibrium IFT between CO2and thecrude oil samples was measured using the axisymmetric drop shape analysis(ADSA) technique. This investigation was followed by measuring theminimum miscibility pressure (MMP) of the oil/CO2systemsusing the vanishing interfacial tension (VIT) technique. The resultsshowed that the density of oil sample increases linearly with pressure.Moreover at a constant pressure and temperature, the density was linearlydecreased with n-heptane content of the crude oilsample. Linear correlations between density, n-heptanecontent, and pressure at the temperature of 323 K for each oil samplewere also noticed. The results of IFT tests indicated that asphalteniccrude oil samples have two slope IFT-pressure behavior. It was foundthat for oil samples with high asphaltene content (9 wt %), the higherthe n-heptane content of the oil sample is, the loweris the pressure of the IFT’s slope change, while for low asphaltenicoil sample (0.56 wt %) an increase of n-heptane haslittle effect on the point of the slope change of the IFT. Consequently,it was found that asphaltenes increase the rate and magnitude of thelight component extraction in oil/CO2systems. The experimentalresults showed that the MMP of the oil samples decreased linearlywith the n-heptane content of the oil sample. Thelinear relation between the MMP and n-heptane contentrevealed the crucial role of the paraffinic group as the controllingmiscibility component of the crude oils. [ABSTRACT FROM AUTHOR]

A facile method that allows for Ni(cod)2 to be used on the benchtop is reported. The procedure involves the preparation of paraffin-Ni(cod)2 capsules, which are stable to air and moisture. It is demonstrated that these readily available capsules can be used to promote a range of Ni(cod)2-catalyzed transformations. These studies are expected to promote the further use of Ni(cod)2 in organic synthesis. [ABSTRACT FROM AUTHOR]

Themicrofibrous entrapped Pt/SAB catalyst (MFEC) was preparedby wet lay-up papermaking with a sintering process. The MFEC withCu-fibers and Ni-fibers has excellent heat transfer properties compareto traditional catalysts via thermal measurements. Thereof, CuMF-Pt/SABcatalyst has lower catalytic properties due to the fact that Cu contaminatesthe catalyst during the sintering process. Although NiMF-Pt/SAB catalysthas good catalytic property, it also has higher selectivity of liquidproducts and lower selectivity of gas products due to the fact thatMFEC can avoid temperature runaways during the hydrocracking reactions.The simulating results confirmed that MFEC has good heat transferand avoid temperature runaways. The pressure drop of MFEC is alsolower than conventional catalyst. Therefore, the Ni MFEC structuresare taken as a suitable catalyst structure to enhance the heat transferfor the exothermic hydrocracking reaction, especially for mild temperaturesin the reaction. [ABSTRACT FROM AUTHOR]

In vertebrates, sialic acids occur at the terminal end of glycans mediating numerous biological processes like cell differentiation or tumor metastasis. Consequently, the cellular sialylation status under healthy and pathological conditions is of high interest. Existing analytical strategies to determine sialylation patterns are mostly applied to tissue samples consisting of a mixture of different cell types. Alterations in the sialylation status in a distinct area of tissues or in a specific cell population may, therefore, be easily overlooked. Likewise, estimated variations in sialylation in tissue homogenates might be simply the result of a changed cell composition. To overcome these limitations, we employed laser microdissection to isolate defined cell types or functional subunits and cell populations of paraffin embedded specimens which represent the most abundant supply of human tissue associated with clinical records. For qualitative and quantitative estimation of the sialylation status, sialic acids were released, fluorescently labeled, and analyzed by an online high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) system. As a proof of principle, this strategy was successfully applied to characterize the sialylation of the apical region of epididymal epithelial cells. Furthermore, it was possible to detect an impaired sialylation during kidney maturation in a transgenic mouse model, which was restricted to glomeruli, whereas no differences in sialylation were observed when whole kidney homogenates were used. Thus, starting from paraffin embedded tissue samples, the outlined approach offers a sensitive method to detect and quantify sialic acids on defined cell populations, which may be useful to explore novel sialic acid dependent roles during physiological and pathological processes. [ABSTRACT FROM AUTHOR]

Oleicacid (OA) was hydrodeoxygenated in this study using zeolite-supportedfluoropalladium oxalate (FPdOx/Zeol) catalyst. The FPdOx/Zeol wasprepared via a pH controlled simple dissolution method and characterizedwith thermal gravimetric analysis, energy dispersive X-ray, X-rayfluorescence, X-ray diffraction (XRD), Fourier transform infraredspectroscopy (FTIR), Raman spectroscopy, and Brunauer–Emmett–Tellertechniques. The results showed that the deposited Pd particle washighly dispersed on the zeolite (Zeol) because of the presence ofoxalate ligands and proper calcination. This observation was corroboratedby the transformation of the Zeol support from crystalline into amorphousin FPdOx/Zeol as seen in the XRD and scanning electron microscopyresults. The best experimental condition for the hydrodeoxygenation(HDO) of 3.5 g of OA was 370 °C, 20 mg of FPdOx/Zeol, and 100mL/min of reducing gas (5% H2/N2) flow rate.The FTIR spectra of the evolved products at these conditions showedthat the HDO of OA proceeded via the formation of stearic acid asintermediate product. A mixture of highly purified paraffinic fuel(iso-octadecane, ∼18%, and n-ocatadecane,∼69%) was obtained after 44 min of HDO. The production of iso-octadecanewhich is an excellent fuel additive because of its antifreezing qualitywas due to the presence of fluoride ion in the FPdOx/Zeol. The FPdOx/Zeoldemonstrated excellent qualities, and the results are promising towardfurther research and industrialization. [ABSTRACT FROM AUTHOR]

Inthis study, interfacial tension measurement (IFT) is utilizedto assess the impact of temperature, pressure, and paraffin type ona nitrogen injection process as an efficient enhanced oil recoverymethod. The pure and equilibrium densities of oil in contact withnitrogen are examined to find IFT behavior and gas solubility in oil.The minimum miscible pressure (MMP) of different systems has beenmeasured using the vanishing interfacial tension technique. The experimentalresults show that IFT decreases linearly with pressure, with two differentslopes. The results indicate that IFT values decrease linearly withtemperature at different pressure conditions. The obtained IFT valuesfor (hexadecane + N2) and (diesel fuel + N2)systems are close to each other. The variation in IFT of nitrogen–paraffinsystems by pressure shows a similar slope to that of the N2and oil mixture (diesel fuel) system. The MMP of different systemswas observed to decrease with increasing temperature. The resultsof this work show that nitrogen injection would be an effective enhancedoil recovery process in high-pressure and high-temperature oil reservoirs. [ABSTRACT FROM AUTHOR]

Previousstudies on gas/vapor separations using polymeric membrane contactorshave always been accompanied with a membrane stability issue: eithera wetting phenomenon or a membrane degradation concern because ofextensive contact with the solvent. To possibly overcome these conventionalchallenges and provide extended stability, the use of a ceramic hollowfiber membrane contactor is proposed in this study where propylene/propaneseparation using silver nitrate as a carrier was investigated fora continuous period of 6 months. Alumina hollow fibers with asymmetricstructures consisting of a spongelike outer layer and a fingerlikeinner layer were successfully fabricated, modified, characterized,and finally examined for propylene/propane separation. The modificationstep using silane solutions was critical in improving the membranehydrophobicity to ensure that no wetting occurred during contact withthe solvent. Initial studies on the separation performance confirmedthat the membrane module was able to operate in a nonwetting mode,where the observed overall mass-transfer coefficient was the highest.Moreover, the ceramic membrane module proved to be stable throughoutcontinuous experiments up to a period of 2 months, where no declinein the performance was observed. However, beyond this investigationperiod, deposition of silver on the membrane surface started to appearsignificantly where the membrane’s appearance becomes dark.This silver deposition seemed to diminish the membrane’s hydrophobicityas it continued to accumulate on the membrane surface, where a slightdecline in the separation performance was finally observed by theend of the 6-month period. By exposing the advantages of ceramic membranesover their polymeric counterparts, a novel regeneration method wasdemonstrated where the membrane module undergoes treatment with strongnitric acid to remove silver deposits, followed by remodificationof the membranes with silane solutions to restore its hydrophobicity.The performance of the membrane modules was regained completely afterregeneration. Thus, this technology can be performed for an extendedperiod without the need to replace the membranes whenever a drop inthe performance is observed due to deformation of the membranes, anissue commonly found with polymeric materials. [ABSTRACT FROM AUTHOR]

Crudeoil reservoirs have different temperatures, compositions, and pressures,therefore oil recovery performance by CO2injection variesfrom one case to another. Furthermore, it is predicted that lowerinterfacial tension between injected CO2and reservoirfluid results in more oil recovery. In this study, we investigatethe effect of temperature on the equilibrium interfacial tension betweenCO2and three different oil fluids at different pressures.Also minimum miscible pressure (MMP) is measured by the vanishinginterfacial tension (VIT) technique to determine the temperature effecton the CO2miscible gas injection. The results on differentpure and mixtures of hydrocarbon fluids show that for pressures upto 5.2 MPa, the higher the temperature was, the lower was the interfacialtension (IFT) measured. However, for the cases with pressure higherthan 5.2 MPa, as the temperature was increased, the IFT increasedtoo. In addition the VIT technique is used to measure the MMP of CO2and pure paraffin; the heavier paraffin was, the higher wasthe MMP noticed. Also, we have learned that paraffin groups have animportant effect on multicomponent interfacial tension behavior. [ABSTRACT FROM AUTHOR]

Organicaerosols have severe effects on human health and climate change. Inthis study, a pilot-scale ceramic filter was used to remove the organicaerosols from furnace flue gas produced from industrial processes.The performance of ceramic filter and long-term stability of ceramicmaterial were investigated. It showed that gas permeation flux fluctuatedat a high level, which was the result of the surface filtration andspecial self-regeneration of the vertical ceramic filter. Removal efficiencies ofTSP, PM10, and PM 2.5 aerosols were higher than 98.5%, and the rejectionmechanisms were concluded as sieving, surface adhesion, and pore channelcapture. Chemical characteristics of aerosol were analyzed based onFTIR spectra. Main organic compounds in the collected aerosols wereparaffin binder, carboxylic acids, and esters. Carboxylic acids andesters were the products of the chemical reactions of paraffin andoxygen at high temperatures. After a long-term operation, ceramicmembranes exhibited low flexural strength loss and slight variationin pore size distribution and the microstructure remained unchanged.Therefore, porous alumina membranes have potential for applicationsin the of removal organic aerosol emissions from industrial processesbefore reaching the atmosphere. [ABSTRACT FROM AUTHOR]

The use of synthetic oils, fats, and fatliquors in theleatherindustry has become popular due to their superiority in terms of highemulsifying power when compared to natural oil based fatliquor. Comparedto natural oil based fatliquor, the quantity required is lesser andthe leather is not unduly loaded with fats and oils to achieve specificsoftness. Generally, synthetic fatliquors are prepared from paraffinsand are made emulsifiable by sulphochlorination to produce chlorinatedparaffin sulphonates. Due to the inherent nature of synthetic fatliquorand its low BOD5/COD ratio of 0.077, it is adsorbed overthe microbes and reduces the efficiency of the aerobic treatment unitin the treatment plants. Hence the aim of the present study was toevaluate the environment friendliness of synthetic fatliquors containingchlorinated paraffin sulphonates, by undertaking aerobic biodegradationstudies at the same operating conditions maintained in the tanneryeffluent treatment plants, viz., f/m ratio of 0.15 and hydraulic retentiontime (HRT) of one day. Considering the nature of the compounds presentin the synthetic fatliquors, the biodegradability of the fatliquorwas sought to be improved by adopting advanced oxidation processes(AOPs) like UV/H2O2and Fenton’s reagentas pretreatment. AOP pretreatment of UV/H2O2and Fenton’s reagent improves the BOD5/COD ratioof synthetic fatliquor from 0.077 to 0.3 and 0.37 and the biodegradableorganics are effectively degraded in the aerobic reactor. UV/H2O2pretreated synthetic fatliquor produced biochemicaloxygen demand (BOD5) and chemical oxygen demand (COD) of45 and 330 mg/L in the aerobic reactor and Fenton’s reagentpretreated fatliquor produced BOD5and COD of 28 and 240mg/L in the aerobic treated effluent. It was evident from FT-IR analysisthat the chlorinated paraffin sulfonates are degraded efficientlyin the batch reactor after AOP pretreatment and short chain chlorinatedcompounds and carboxylic acids presence are observed in the operatingconditions maintained in the batch aerobic reactors. [ABSTRACT FROM AUTHOR]

Oil-in-water nanoemulsions were produced in the systemwater/Span 80–Tween 80/paraffin oil via the phase inversioncomposition (PIC) method at elevated temperature. With the increaseof preparation temperature from 20 to 70 °C, we found that theemulsion droplet diameter decreases from 10.3 μm to 51 nm, provingthe formation of nanoemulsions. The viscosity of nanoemulsions clearlyincreases with droplet volume fraction, φ, but the droplet sizechanges less. Significantly, at φ ≤ 0.5, the size distributionof nanoemulsions can be kept unchangeable more than 5 months. Theseresults proved that the highly viscous paraffin oil can hardly bedispersed by the PIC method at 25 °C, but the increase in preparationtemperature makes it possible for producing monodisperse nanoemulsions.Once the nanoemulsion is produced, the stability against Ostwald ripeningis outstanding due to the extremely low solubility of the paraffinoil in the continuous phase. The highly stable nanoemulsions are ofgreat importance in practical applications. [ABSTRACT FROM AUTHOR]

Our dynamic mechanical measurements in the glass–rubbertransition zone of polyisobutylene (PIB), expressed in terms of therelaxation spectrum H(τ) and loss tangent (tanδ), have found an additional shoulder. Following the interpretationof previous works, the shoulder is attributed to the sub-Rouse modes,which account for motions intermediate in length scale to the Rouseand local segmental modes. The fact that the sub-Rouse modes are wellresolved in PIB and not in other amorphous polymers was traced toits weak intermolecular coupling, which ultimately originates fromthe compact and symmetrical structure of its repeat unit. We testthis interpretation further by studying the change on adding liquidparaffin (LP) to PIB, which should disrupt the effective chain packingof undiluted PIB. We found on adding LP to PIB that the softeningdispersion becomes narrower, and eventually the disappearance of theshoulder. The effect is due to the mobility of entropic Rouse modesenhanced significantly more than that of the sub-Rouse modes and theenthalpic local segmental motion on increasing the weight fractionof LP. Thus, the Rouse modes get closer to the sub-Rouse modes andlocal segmental motion. Incorporation of LP does not reduce much theintermolecular coupling, as evidenced by the small change of glasstransition temperature. On the other hand, the disruption of the effectivechain packing of PIB by adding LP endows higher mobility to the Rousemodes with longer motional units, while it has little effect on thelocal segmental relaxation and the sub-Rouse modes. Consequently,there is the narrowing of the softening dispersion and eventuallythe disappearance of the shoulder in H(τ) andtan δ. The result supports the compact and symmetric chemicalstructure of the repeat unit of PIB, and the efficient chain packingis the root cause that engenders the broad softening dispersion, andthe observation of the sub-Rouse modes in H(τ)and tan δ. Positron annihilation lifetime spectra are presentedto show the average size and concentration of the free-volume holesincrease with incorporation of LP and the disruption of the effectivechain packing of PIB. [ABSTRACT FROM AUTHOR]

The use of asphalt emulsions for road fabrication is rapidly gaining in importance mainly due to energy savings, less environmental impact, and better properties of the final product. However, the formulation of these emulsions still requires a better understanding, particularly concerning their breaking phenomena. When a cationic model emulsion is contacted with a solid having a negative-charged surface, physicochemical driving forces result in the emulsion destabilization. As a consequence, a viscosity reduction of the remaining emulsion is observed, as well as the emulsion breakup through a heteroflocculation mechanism provided the solid surface is large enough. Emulsion systems at equilibrium, containing cetylpyridinium chloride (CPC), paraffin oil, and Fontainebleau's sandstone powder and having different droplet sizes, are studied. The results show that the dispersed oil fraction decreases after each addition of sandstone aliquots, and this depends on the concentration of CPC in the continuous phase of the emulsion. As the droplet size and distribution remain constant during the process, it is assumed that the emulsion heteroflocculation is the result of direct oil droplets adhesion on the sand surface, followed by their coalescence around the sand particles. [ABSTRACT FROM AUTHOR]

The unprecedented interdigitated and layered structuresof 1,1′,3,3′-tetra(2-methyl-2-nonyl)ferrocene(DEC) and the oxoanion ferrocenium salts DEC㓭–, DEC੓–, and DEC䗣–were determinedby single-crystal X-ray diffraction. The four structures are similarexcept that the three DEC놩 have layers of XOn–oxoanions stuffed betweenthe layers of interdigitated ferrocenium ions. The perpendicular distancesbetween layers of Fe atoms are 8.530, 9.108, 9.009, and 9.158 Åfor DEC, DEC㓭–, DEC੓–, and DEC䗣–, respectively. The structures also containlayers of rigorously coplanar Fe and X atoms that are tilted 65.4,75.9, 61.9, and 61.1° from the aforementioned layers of Fe atomsfor DEC, DEC㓭–, DEC੓–, and DEC䗣–, respectively. The local environmentsof the XOn–oxoanionsconsist of networks of C–H···O hydrogen bonds,and the structures exhibit channels through which these anions coulddiffuse. Facile diffusion of these anions in thin films of DEC峩–, with structuresthat appear to resemble the crystal structures, has been demonstrated. [ABSTRACT FROM AUTHOR]

This paper reports for the first time the electrogenerated chemiluminescence (ECL) behavior of graphite-like carbon nitride (g-C3N4) with K2S2O8 as the coreactant. The possible ECL reaction mechanisms are proposed. The spectral features of the ECL emission and photoluminescence (PL) of g-C3N4 are compared, and their resemblance demonstrates that the excited states of g-C3N4 from both ECL and photoexcitation are the same. The effects of K2S108 concentration, pH, g-C3N4 carbon powder ratio, and scan rate on the ECL intensity have been studied in detail. Furthermore, it is observed that the ECL intensity is efficiently quenched by trace amounts of Cu2+ g-C3N4 is thus employed to fabricate an ECL sensor which shows high selectivity to Cu2+ determination. The limit of detection is determined as 0.9 nM. It is anticipated that g-C3N4 could be a new class of promising material for fabricating ECL sensors. [ABSTRACT FROM AUTHOR]

The effects of salt on emulsions containing sorbitanoleate (Span80) and Laponite particles were investigated. Surprisingly, a noveldouble phase inversion was induced by simply changing the salt concentration.At fixed concentration of Laponite particles in the aqueous phaseand surfactant in paraffin oil, emulsions are oil in water (o/w) whenthe concentration of NaCl is lower than 5 mM. Emulsions of water inoil (w/o) are obtained when the NaCl concentration is between 5 and20 mM. Then the emulsions invert to o/w when the salt concentrationis higher than 50 mM. In this process, different emulsifiers dominatethe composition of the interfacial layer, and the emulsion type iscorrespondingly controlled. When the salt concentration is low inthe aqueous dispersion of Laponite, the particles are discrete andcan move to the interface freely. Therefore, the emulsions are stabilizedby particles and surfactant, and the type is o/w as particles arein domination. At intermediate salt concentrations, the aqueous dispersionsof Laponite are gel-like, the viscosity is high, and the transitionof the particles from the aqueous phase to the interface is inhibited.The emulsions are stabilized mainly by lipophilic surfactant, andw/o emulsions are obtained. For high salt concentration, flocculationoccurs and the viscosity of the dispersion is reduced; thus, the adsorptionof particles is promoted and the type of emulsions inverts to o/w.Laser-induced fluorescent confocal micrographs and cryo transmissionelectron microscopy clearly confirm the adsorption of Laponite particleson the surface of o/w emulsion droplets, whereas the accumulationof particles at the w/o emulsion droplet surfaces was not observed.This mechanism is also supported by the results of rheology and interfacialtension measurements. [ABSTRACT FROM AUTHOR]

Nearly all reported approaches for synthesis of high quality CdSe nanocrystals (NCs) involved two steps of preparation of Cd or Se stock solution in advance and then mixing the two reactants via hot-injection in high temperature. In this manuscript, Gram-scale CdSe multipod NCs were facilely synthesized in a noninjection route with the use of CdO and Se powder directly as reactants in paraffin reaction medium containing small amount of oleic acid and trioctylphosphine. The influence of various experimental variables, including reaction temperature, nature and amount of surfactants, Cd-to-Se ratio, and the nature of reactants, on the morphology of the obtained CdSe NCs have been systematically investigated. After deposition of ZnS shell around the CdSe multipod NCs, the PL QY of the obtained CdSe/ZnS can be up to 85%. The reported noninjection preparation approach can satisfy the requirement of industrial production bearing the advantage of low-cost, reproducible, and scalable. Furthermore, this facile noninjection strategy provides a versatile route to large-scale preparation of other semiconductor NCs with multipod or other morphologies. [ABSTRACT FROM AUTHOR]

Tri-n-butyl phosphate (TBP) in diluent is generally used as a solvent for the extraction of fissile materials in the reprocessing of spent fuels by the PUREX process. The mutual solubility of TBP and water leads to the transfer of some finite amount of TBP into the aqueous phase. The distribution study of TBP between normal paraffin hydrocarbon (NPH) and nitric acid has been studied. Equilibrium curves have been generated for TBP in different concentrations of nitric acid and NPH. The distribution coefficient (Kd) is also calculated by measuring the concentration of associated TBP in the aqueous and organic phase. The effect of an inert diluent on the solubility of TBP in nitric acid is also studied. It has been found that the distribution coefficient value varies with the concentration of TBP, nitric acid, and NPH. Nitric acid partitioning between TBP and water has also been studied. The concentration of nitric acid in both phases was determined by the titration method. It has also been proven that the concentration of nitric acid varies during this equilibrium study due to 1:1 complex formation with TBP by hydrogen bonding. The equilibrium study of this TBP-NPH-nitric acid system will aid in finding out the amount of TBP in different concentrations of nitric acid in the presence of a diluent. This study will be useful in nuclear waste management generated by spent fuels of reprocessing origin. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate whether paraSogue ratio tests (PRT) using real-time PCR can accurately determine the DNA copy number (CN) using formalin fixed paraffin embedded (FFPE) tissue. Histopathol-ogy diagnostic archives are an enormous resource of FFPE tissue, but extracted DNA is of poor quality and may be unsuitable for CN assessment, thus representing a missed opportunity for studies of genetic association and somatic change in cancer in large cohorts of easily accessible samples. Assays with paralogues on chromosomes 18 and 20 (18∣20 PRT) and chromosomes 13 and X (13∣X PRT) were tested using archived FFPE pathology samples with known CN, including tonsil, placentae, and FFPE melanoma cell lines. The assay proved accurate over the dynamic range from 1:1 to 1:3 and gave precise results when repeated four times over several weeks. The precision of the assay was marginally reduced once the CT value for 10 ng of FFPE DNA increased above 30 cycles, reflecting importance of DNA quality. The assays distinguished changes in CN ratio with high sensitivity and specificity. The 13∣X PRT could detect cells with distinct genotypes microdissected from within the same FFPE sample. Therefore, PRTs are suitable for analyzing CN in FFPE tissues. [ABSTRACT FROM AUTHOR]

An evaluation using paraffin oil based, Acheson 38 carbon paste electrodes modified with α-hydroxyisobutyric acid (HIBA) to preconcentrate f-elements cathodically is described. The modified paste was made by directly mixing solid HIBA into the carbon paste. A chemically reversible cyclic voltammogram for HIBA was observed on this modified carbon paste, which was found to be a non-Nerstian, single electron transfer process. Lanthanides (less promethium) were found to accumulate onto the electrode surface during a 30 electrodeposition step at -0.4 V vs Ag/AgCl from 0.1 M LiCl. The elements were then stripped off into a 2% HNO3 solution by an oxidative step at +0.8 V vs Ag/AgCl; quantitative removal from the electrode was confirmed by ICPMS. Ultratrace solutions with initial concentrations down to 5 parts per quadrillion (ppq) were preconcentrated in 5 min above our instrumental limit of detection (LOD) of around 1 ppt for lanthanides. [ABSTRACT FROM AUTHOR]

To understand the flow improvement of waxy oils by comb-type polymer additives, the crystallization of long-chain n-paraffins from solutions of decane was studied by X-ray diffraction. The effects of poly(ethylene-butene) (PEB) and poly(maleic anhydride amide-co-α-olefin) (MAC) polymers on the crystallization of C28, C32, and C36 n-paraffins and their mixtures were studied. In the absence of the polymer additives, paraffin platelet crystals give well-resolved low-angle spectra. PEB and MAC reduce the low-angle scattering from the layered structure, which is expected since the polymers cocrystallize with the paraffin and the noncrystallizable portion of the chain provides a steric barrier against platelet stacking. This is consistent with observations by optical microscopy and differential scanning calorimetry and can account for the significant reduction of yield stresses of model waxy oils upon addition of these polymers. The assembly of PEB and MAC with paraffins during crystallization results in improved flow of waxy oils on cooling. X-ray diffraction also reveals that the cooling rate has significant impact on the crystal structure of long-chain n-paraffins. [ABSTRACT FROM AUTHOR]

Microencapsulation of PRS paraffin wax was carried out by means of suspension-like homopolymerization of methyl methacrylate (MMA) and by the copolymerization of this monomer with methyl acrylate (MA) and methacrylic acid (MAA). The influence of the type of monomers and their proportion as shell materials, the mass ratio of polyvinylpyrrolidone to monomers (PVP/monomers), and the mass ratio of PRS paraffin wax to monomers (PRS/monomers) on the properties of phase change material (PCM) microcapsules has been studied. The analytical techniques used for the characterization of the particles were differential scanning calorimetry (DSC) and modulated DSC, dynamic light scattering, environmental scanning electron microscopy (ESEM) and gel permeation chromatography (GPC). The chemical property differences between the encapsulating “shell” material, acrylic polymer in this case, compared to the “core” material (PRS paraffin wax), such as polarity and interfacial tensions, largely determine the thermodynamically favored morphology of the microcapsules. While the equilibrium morphology was a core/shell structure, kinetic factors relating to the competition between the fast acrylic polymerization rate and the diffusion limited rate of phase separation were found to constrain the ability of the system to approach that equilibrium structure. For both homopolymerization of methyl methacrylate (PMMA) and copolymerizations of methyl methacrylate with methyl acrylate (P(MMA-co-MA)), “pomegranate” microspheres were observed with a thin acrylic shell surrounding an inner composite structure constituted by a paraffin matrix with a dense assortment of PMMA spherical domains. Ter-polymerizations incorporating methacrylic acid (P(MMA-co-MA-co-MAA) had a remarkable effect on the morphology and average particle size, resulting again in “pomegranate” microparticles but where the internal PMMA spheroids were more densely populated closer to the outer portion of the capsule; approaching a core/shell structure. As the amount of polyvinylpyrrolidone stabilizer in the aqueous medium was increased and the PRS/monomers proportion was decreased, the mean particle size of the microcapsules decreased. However, higher PVP/monomer and PRS/monomer ratios led to less efficient encapsulation of the PRS paraffin wax. Near perfect encapsulation efficiency was obtained for two pairings of these ratios via P(MMA-co-MA-co-MAA) polymerization, but only up to an equal mass ratio of PRS to acrylic polymer. [ABSTRACT FROM AUTHOR]

This article describes an integrated approach to tracking the end point of a time-based assay that is conducted on an analytical device made out of paper. The liming mechanism is built directly into a paper-based analytical device and does not require starting, stopping, reset buttons, batteries, or maintenance; the timer simply starts once the sample is added to the device. These "fluidic timers" are composed of paraffin wax and a signaling feature (e.g., a dye). The timing function is made possible by the specific lime required for a liquid sample to wick through predefined regions in the device. This time period can be anywhere between 1 mm and 2 h and is controlled by the quantity of wax present in the timer. Because both the fluidic timers and paper-based assays depend on the wicking rate of the sample, the fluidic timers automatically calibrate themselves (relative to the assay) to account for differences in wicking rates that are caused by variations in humidity. Fluidic timers are 97% accurate (with respect to the time required for the assay) and provide slightly better accuracy than an external timer when used to track an assay that measured the level of glucose in a sample. [ABSTRACT FROM AUTHOR]

In this paper we present a simple and rapid method of modifying poly(dimethylsiloxane) (PDMS) surfaces with paraffin wax. PDMS that contains a layer of paraffin wax at its surface resists the absorption of hydrophobic molecules; we used fluorescence microscopy to confirm that paraffin-modified PDMS resists the absorption of rhodamine B. Furthermore, we demonstrated that microfluidic devices made from PDMS that contains a surface layer of paraffin wax prevent efficiently the transport of gas molecules through the bulk and into microchannels. We characterized the surface of PDMS that contains paraffin wax using the water contact angle, optical transmission, and X-ray photoelectron spectroscopy. We show that PDMS that contains paraffin wax can be substituted for native PDMS; specifically, we fabricated peristaltic valves in PDMS that contains paraffin wax, and the valves showed no degradation in performance after multiple open/close cycles. Finally, we show how to use PDMS that has been treated with paraffin wax as a mold for the fabrication of PDMS replicas; this approach avoids silanization of PDMS, which is a time-consuming step in soft lithography. The wax-modified PDMS channels also show performance superiro to that of bare PDMS in micellar electrokinetic chromatography for quantitative analysis. [ABSTRACT FROM AUTHOR]

The influences of metal (iron, magnesium, aluminum, and zinc) on thermal properties for paraffin/intumescent flame retardants (IFR) as a phase change material were studied in this paper. Thermogravimetric analysis (TGA), thermogravimetric analysis−Fourier transform infrared spectrometry (TGA-FTIR), microscale combustion calorimetry (MCC), cone calorimetry (CONE), and differential scanning calorimetry (DSC) were used to characterize the thermal properties of the sample. The results revealed that metal could affect the thermal degradation and increase the char yield for a paraffin/IFR system. The volatilized products for the combustible gases were decreased, and carbon dioxide was increased for paraffin/IFR with metal compared to that without metal. Also, the flame retardant efficiency of IFR in paraffin could be improved by adding metal. However, the changes of the thermal properties for the metal−PCM were not in accord with increasing metal in the paraffin/IFR system. Also, the flame retardant mechanism for paraffin/IFR with metal was proposed. [ABSTRACT FROM AUTHOR]

This article describes an exceedingly simple and low-cost method for metering the capillary-driven flow rate of fluids within three-dimensional (3D) microfluidic, paper-based analytical devices (μPADs). Initial prototypes of 3D μPADs control the spatial distribution of fluids within a device, but they provide little control over how quickly (or slowly) fluids move within the device. The methods described in this article provide control over when and how quickly a fluid is distributed into detection zones. These methods are inexpensive (the metering regions are composed of paraffin wax), the devices are easy to fabricate, and they are capable of controlling the flow of fluids to detection zones with precise time delays (e.g., ±6% of the total wicking time). We anticipate that this type of precise control over fluid distribution rates will be useful particularly for point-of-care assays that require multiple steps (where each step requires that the reagents interact for a defined period of time) or for simultaneously displaying the results of multiple different assays on a single device. [ABSTRACT FROM AUTHOR]

The ion exchange of octosilicate with a series of quaternary organoammonium ions was examined. The ion exchange proceeds almost quantitatively to replace the interlayer sodium ions. When n-alkyltrimethylammonium ions were exchanged with sodium ions, the basal spacings increased with the alkyl chain length, showing the formation of paraffin type surfactant aggregates in the interlayer space. When the organic cations with complex molecular geometry (dimethyldioctadecylammonium, N-(α-trimethylammonioacetyl)-didodecyl-l-glutamate, and O,O′,O′′-tridodecanoyl-N-(ω-trimethyl ammoniodecanoyl)-tris(hydroxymethyl)aminomethane) were used, the basal spacings changed as a function of the molecular weight of the intercalated guest species. It is speculated that the molecular geometries of the intercalated species are flexible to form densely packed nanostructures in the interlayer space. [ABSTRACT FROM AUTHOR]

Hydrogenation of oxidized wax to produce an oxidized wax enriched in sec-alcohols was investigated experimentally. Hydrogenation over copper chromite catalysts resulted in an alcohol yield of 50−55% at 180−190 °C, 10 MPa of hydrogen pressure, and liquid hourly space velocity of 0.4 h−1. Hydrogenation at temperatures above 200 °C resulted in significant overhydrogenation of the oxidized wax to paraffins. Copper chromite catalysts were also found to be active for the esterification of carboxylic acids with alcohols. The combination of copper chromite with Ru/C increased carboxylic acid conversion, but did not improve the overall alcohol yield. The results from the experimental work were employed in conjunction with previous studies to propose a process for the production of olefins from paraffins by autoxidation, selective hydrogenation, and alcohol dehydration. All of these processing steps can be performed at <300 °C. [ABSTRACT FROM AUTHOR]

Most adsorbent materials used for olefin/paraffin separation show preferential adsorption of the olefin. Recently, the material aluminum methylphosphonate polymorph alpha (AlMePO-α) was found to be able to selectively adsorb the paraffin instead of the olefin, from an ethyl chloride/vinyl chloride mixture (Herdes, C.; Valente, A.; Lin, Z.; Rocha, J.; Coutinho, J. A. P.; Medina, F.; Vega, L. F. Langmuir2007, 23, 7299). However, several questions remain still open regarding the reasons for this selective paraffin adsorption, as well as the suitability of AlMePO-α as adsorbent for other olefin/paraffin separations. In this work, the adsorption of ethane/ethylene mixtures by AlMePO-α is investigated using grand canonical Monte Carlo simulations in order to determine the effect of molecular interactions, size, and shape on the selective adsorption. For this purpose three different force fields have been used for the fluids, investigating the effect of the molecular details of the fluid on the adsorption behavior. All three force fields gave the same qualitative behavior. It was found that AlMePO-α is also able to selectively adsorb the paraffin from ethane/ethylene mixtures. Moreover, ethane molecules arrange exactly in the same way in the adsorbent material as ethyl chloride, with the methyl groups directed toward each other, although ethane has much smaller dynamic diameter compared to ethyl chloride. Therefore, a key factor determining the selectivity is found to be the molecular interaction between the methyl group of AlMePO-α and the methyl group of the paraffin. [ABSTRACT FROM AUTHOR]

Microcapsules with a high amount of PRS paraffin wax encapsulated and narrow size distribution were prepared by a Shirasu porous glass (SPG) emulsification technique and a subsequent suspensionlike polymerization process. An experimental design approach, based on a central composite design, was used to determine quantitatively the effect of RepSol-YPF Paraffin (PRS) paraffin wax/styrene mass ratio (PRS/St), percentage of polyvinylpyrrolidone/styrene mass ratio (% PVP/St), and water/styrene mass ratio (H2O/St) on the phase change material (PCM) microcapsules properties. The % PVP/St mass ratio was the most important parameter affecting the particle size distribution. The thermal energy storage of microcapsules increases with the PRS/St mass ratio used. The following synthesis conditions, mass ratios PRS/St of 1.02, % PVP/St of 9.43, and H2O/St of 8.23, allowed the the proper main particle size in number (4.80 μm) for fabrics applications containing the maximum phase change material encapsulated with a latent heat of 102.42 J/g to be achieved. [ABSTRACT FROM AUTHOR]

HYSYS-based process simulation was accomplished for a recently reported 1-butene + isobutane alkylation concept that employs SiO2-supported Nafion catalyst in dense CO2media to obtain stable C8alkylates production (solid acid/CO2process). Semiquantitative economic and environmental impact assessments were conducted for this novel process design along with comparative assessments for a conventional sulfuric acid catalyzed alkylation process (at equivalent production capacities). The simulations are commercial scale and are based on available data and reasonable process assumptions. The total capital investment of the solid acid/CO2process is approximately 20−30% higher than that of the sulfuric acid process. Sensitivity analysis shows that, if the olefin space velocity can be increased by a factor of 4 from the base-case value while maintaining the same C8alkylate productivity, the total capital investments along with the utility and chemical costs would be nearly the same for both processes. The environmental impact assessment shows that the conventional sulfuric acid process has a 3.9 times higher adverse environmental impact potential than the solid acid/CO2process. For the sulfuric acid process, the major contributors to the environmental impact are acid rain (66%) and inhalation toxicity (32%). The main pollution comes from the SO2emissions during sulfuric acid regeneration (53%) and acid leakage in the alkylation unit (10%). For the solid acid/CO2process, the major contributors to the environmental impact are inhalation toxicity (83%), global warming (10%), and acid rain (6%). For the solid acid/CO2process, the main pollution sources are fugitive emissions. This evaluation illustrates the advantages and shortcomings of the novel process and provides rational research guidance. For example, the analyses established performance targets, such as catalyst activity and operating pressure, for the solid acid/CO2process to be commercially viable. [ABSTRACT FROM AUTHOR]

This study aims to develop IR imaging of tumor tissues for generating an automated IR-based histology. Formalin-fixed paraffin-embedded xenografts of human colon carcinomas were analyzed. Chemometric and statistical multivariate treatments of spectral data permitted to probe the intrinsic chemical composition of tissues, directly from paraffinized sections without previous dewaxing. Reconstructed color-coded spectral images revealed a marked tumor heterogeneity. We identified three spectral clusters associated to tumoral tissues, whereas HE staining revealed only a single structure. Nine other clusters were assigned to either necrotic or host tissues. This spectral histology proved to be consistent over multiple passages of the same xenografted tumor confirming that intratumoral heterogeneity was maintained over time. In addition, developing an innovative image analysis, based on the quantification of neighboring pixels, permitted the identification of two main sequences of spectral clusters related to the tissue spatial organization. Molecular attribution of the spectral differences between the tumor clusters revealed differences of transcriptional activity within these tumor tissue subtypes. In conclusion, IR spectral imaging proves to be highly effective both for reproducible tissue subtype recognition and for tumor heterogeneity characterization. This may represent an attractive tool for routine high throughput diagnostic challenges, independent from visual morphology. [ABSTRACT FROM AUTHOR]

The paper reports on obtaining highly dispersed chromium(III) silicates and chromium(III) oxides from postchromating waste by reduction of Cr(VI) to Cr(III) with hydrazine as a reducing agent Chromium(III) salt solution and sodium silicate or hydroxide solutions have been used to precipitate green pigments (silicates and oxides). The effect of the precipitation parameters on the quality of green pigments obtained has been studied, and the optimum parameters ensuring getting the product of well-developed surface area and possibly lowest diameter of primary particles have been established. The precipitated silicates and oxides have been subjected to physicochemical analysis to determine bulk density; capacities to absorb water, dibutyl phthalate, and paraffin oil; particles size; particle size distribution; and surface morphology of chromium pigment surfaces. The adsorptive properties of the oxide and silicate pigments have also been examined. The XRD analysis documented that the chromium(III) silicate pigments obtained are amorphous. In addition, the pigments have been subjected to a colorimetric appraisal using the CIE L*a*b* color space system. The high-quality green pigments obtained have shown high dispersion, small tendency to agglomerate formation, and repeatable green hue. The parameters of the products are promising for their future technological use. [ABSTRACT FROM AUTHOR]

In an attempt to develop a high-throughput culture process, bacterial cells were encapsulated in uniform-sized agarose microcapsules prepared by membrane emulsification method. A mixture of diluted bacterial cell suspensions and agarose aqueous solution (40 °C) was used as the water phase, and a mixture of liquid paraffin and petroleum ether that contained hexaglycerin penta ester (PO-500) was used as the oil phase. The water phase permeated through uniform membrane pores into the oil phase under the pressure of nitrogen gas to form a uniform water/oil (W/O) emulsion; the emulsion then was cooled to form uniformly sized gel capsules. The size of microcapsules can be controlled by membranes with different pore sizes, because the mean diameters of the capsules were proportional to the mean pore diameters of the membranes. These microcapsules, which contained bacterial cells, were transferred into a column vessel and were incubated for 14 days to form microcolonies within the microcapsules. The cultured microcapsules were analyzed by flow cytometry, and the microbial colonized capsules were separated from free-living cells and empty capsules, based on the distinctive light-scattering signature of the microcapsules. The result showed that membrane emulsification preserved the viability of cells and this method was effective to create niches for various bacterial cells growing in high-throughput cultivation vessels. [ABSTRACT FROM AUTHOR]

To study the formation of air pollutants and soot precursors (e.g., acetylene, 1,3-butadiene, benzene, and higher aromatics) from aliphatic and aromatic fractions of gasoline fuels, the Utah Surrogate Mechanisms is extended to include submechanisms of gasoline surrogate compounds using a set of mechanism generation techniques. The mechanism yields very good predictions of species concentrations in premixed flames of n-heptane, isooctane, benzene, cyclohexane, olefins, oxygenates, and gasoline using a 23-component surrogate formulation. The 1,3-butadiene emission comes mainly from minor fuel fractions of olefins and cyclohexane. The benzene formation potential of gasoline components shows the following trends as functions of (i) chemical class: n-paraffins < isoparaffins < olefins < naphthalenes < alkylbenzenes < cycloparaffins < toluene; (ii) carbon number: n-butane < n-pentane < n-hexane; and (iii) branching: n-hexane < isohexane < 2,2,4-trimethylpentane <2,2,3,3-tetramethylbutane. In contrast, fuel structure is not the main factor in determining acetylene formation. Therefore, matching the benzene formation potential of the surrogate fuel to that produced by the real fuel should have priority when selecting candidate surrogate components for combustion simulations. [ABSTRACT FROM AUTHOR]