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Low grade heat still widely exists in energy-intensive industrial parks, although good energy integration has been accomplished for individual processes or plants. Low grade heat is notably large but difficult to utilize because of the limitation of heat transfer and the scarcity of low grade heat sinks. Large scale utilization of low grade heat is very challenging for energy-intensive industries or industrial parks. A large scale low grade heat recovery, refrigeration, and utilization network system is introduced in this study to improve energy performance for industrial parks. In order to model the large scale system, the system is decomposed into three levels: pipe networks, refrigeration stations and absorption chillers. A mixed integer nonlinear programming model is presented that considers mass and energy networks, pipes, refrigeration stations, absorption chillers, and economic performance. The mathematical model is applied to the optimization and economic analysis for the low grade heat utilization in a petrochemical industrial park in China. The model can be solved in available time using the global solver. The solution results demonstrate the good economic performance of the new low grade heat recovery, refrigeration, and utilization network system for the industrial park. [ABSTRACT FROM AUTHOR]

A combination of hard phase CoFe2O4 and soft phase MnFe2O4 as the bimagnetic nanocrystals in a core-shell architecture has been synthesized, and their magnetic properties have been systematically studied. Both HRTEM andi EDS results confirmed the formation of bimagnetic core-shell structured nanocrystals. On the basis of the systematic and comparative studies of the magnetic properties of a mechanical mixture of pure CoFe2O44 and MnFe2O4 nano- crystals, chemically mixed Co1-xMn-xFe nanocrystals, and bimagnetic core-shell CoFe2O4@MnFe2O4 and MnFe2O4@CoFe2O4 nanocrystals, the bimagnetic core-shell nanocrystals show very unique magnetic properties, such as the blocking temperature and coercivity. Our results show that the coercivity correlates with the volume fraction of the soft phase as the theoretical hard-soft phase model has suggested. Furthermore, switching the hard phase CoFe2O4 from the core to the shell shows great changes in the coercivity of the nanocrystals. The bimagnetic core- shell nanocrystals evidently demonstrate the rational design capability to separately control the blocking temperature and the coercivity in magnetic nanocrystals by varying the materials, their combination, and the volume ratio between the core and the shell and by switching hard or soft phase materials between the core and shell. Such controls via a bimagnetic core-shell architecture are highly desirable for magnetic nanocrystals in various applications. [ABSTRACT FROM AUTHOR]

By combining nonhydrolytic reaction with seed-mediated growth, high-quality and monodisperse spinel cobalt ferrite, CoFe2O4, nanocrystals can be synthesized with a highly controllable shape of nearly spherical or almost perfectly cubic. The shape of the nanocrystals can also be reversibly interchanged between spherical and cubic morphology through controlling nanocrystal growth rate. Furthermore, the magnetic studies show that the blocking temperature, saturation, and remanent magnetization of nanocrystals are solely determined by the size regardless the spherical or cubic shape. However, the shape of the nanocrystals is a dominating factor for the coercivity of nanocrystals due to the effect of surface anisotropy. Such magnetic nanocrystals with distinct shapes possess tremendous potentials in fundamental understanding of magnetism and in technological applications of magnetic nanocrystals for high-density information storage. [ABSTRACT FROM AUTHOR]

To understand the influence of surface interactions upon the magnetic properties of magnetic nanoparticles, the surface of manganese ferrite, MnFe[sub 2]O[sub 4], nanoparticles have been systematically modified with a series of para-substituted benzoic acid ligands (HOOC-C[sub 6]H[sub 4]-R; R = H, CH[sub 3], CI, NO[sub 2], OH) and substituted benzene ligands (Y-C[sub 6]H[sub 5], Y = COOH, SH, NH[sub 2], OH, SO[sub 3]H). The coercivity of magnetic nanoparticles decreases up to almost 50% upon the coordination of the ligands on the nanoparticle surface, whereas the saturation magnetization has increased. The percentage coemivity decrease of the modified nanoparticles with respect to the native nanoparticles strongly correlates with the crystal field splitting energy (CFSE) Δ evoked by the coordination ligands. The ligand inducing largest CFSE results in the strongest effect on the coercivity of magnetic nanoparticles. The change in magnetic properties of nanoparticles also correlates with the specific coordinating functional group bound onto the nanoparticle surface. The correlations suggest the decrease in spin-orbital couplings and surface anisotropy of magnetic nanoparticles due to the surface coordination. Such surface effects clearly show the dependence on the size of nanoparticles. [ABSTRACT FROM AUTHOR]

Provides information on an study of the magnetic properties of spinel nanoparticles determining the crystal chemistry issues such as cation distribution and oxidation states. Methodology used to conduct the study; Results of the study; Discussion on the results.

Examines the sorption and desorption of three quaternary amines on clays using a titration procedure. Two types of reactions; Presence of clay solutions; Percentage of sorbed quaternary amine cations; Effect of prolonged equilibrium time; Use as effective sorbents.

Discusses the atom transfer radical polymerization (ATRP) synthesis and magnetic characterization of polystyrene core/shell nanoparticles. Applications of methods to coat a polymer shell; Advantages of the ATRP technique over other polymerization methods; Thermal polymerization of styrene.

A heterogeneous reaction mechanismbased on elementary reactionsteps is proposed for the prediction of pyrolytic carbon depositionin chemical vapor infiltration, involving 72 surface species and 277surface elementary reactions. A “prototype” gas-phasereaction is chosen to match with the corresponding surface reaction,and correction methods for kinetic data are also proposed for threekinds of surface reactions (i.e., surface/gas reactions, unimolecularsurface reactions, surface/surface reactions) in the present work.Simulation results of deposition kinetics and gas-phase compositionsof propane pyrolysis are validated by previously published experimentalresults of Marquaire’s group, with a surface to volume ratiofrom 5 to 175 cm–1and temperature from 1173 to1323 K. The reaction pathways of the heterogeneous surface reactionsand homogeneous gas-phase reactions are studied on the basis of thereaction flow rate analysis. An acceptable agreement indicates thatthe present heterogeneous reaction mechanism is reasonable, and acetylene,ethylene, and benzene are recognized as the main precursors of thepyrolytic carbon deposition at the present processing conditions. [ABSTRACT FROM AUTHOR]

In order to expand our understanding of a potential zinc-basedbattery electrolyte, we have characterized the physical and transportproperties of the ionic liquid (IL) 1-butyl-1-methylpyrrolidiniumdicyanamide ([C4mpyr][dca]) containing various levels ofboth Zn2+and H2O. Detailed measurements ofdensity, viscosity, conductivity, and individual anion and cationdiffusion coefficients using pulsed-field-gradient (PFG) NMR combinedwith NMR chemical shifts and spin–lattice relaxation (T1) NMR experiments provide insights into themotion and chemical environment of all molecular species. We findthat the various techniques for probing ion transport and dynamicsform a coherent picture as a function of electrolyte composition.Zn2+addition causes a moderate reduction in the self-diffusionof the IL anion and cation, whereas the addition of H2Oincreases ion mobility by increasing the liquid’s overall fluidity.Temperature-dependent 13C T1experiments of the dca carbon analyzed using Bloembergen–Purcell–Poundfits show monotonic slowing of anion dynamics with Zn2+addition, suggesting increased Zn2+/dca–association. T1experiments show minimalchange in the spin–lattice relaxation of cation or anion uponH2O addition, suggesting that H2O is playingno significant role in Zn2+speciation. Finally, we employa novel electrophoretic NMR technique to directly determine the electrophoreticmobility of the C4mpyr cation, which we discuss in thecontext of impedance-based conductivity measurements. [ABSTRACT FROM AUTHOR]

The objective of this study was to quantify transport of Eu colloids in the vadose zone at the semiarid Hanford site. Eu-hydroxy-carbonate colloids, Eu(OH)(CO3), were applied to the surface of field lysimeters, and migration of the colloids through the sediments was monitored using wick samplers. The lysimeters were exposed to natural precipitation (145-231 mm/year) or artificial irrigation (124-348 mm/year). Wick outflow was analyzed for Eu concentrations, supplemented by electron microscopy and energy-dispersive X-ray analysis. Small amounts of Eu colloids (<1%) were detected in the deepest wick sampler (2.14 m depth) 2.5 months after application and cumulative precipitation of only 20 mm. We observed rapid transport of Eu colloids under both natural precipitation and artificial irrigation; that is, the leading edge of the Eu colloids moved at a velocity of 3 cm/day within the first 2 months after application. Episodic infiltration (e.g., Chinook snowmelt events) caused peaks of Eu in the wick outflow. While a fraction of Eu moved consistent with long-term recharge estimates at the site, the main mass of Eu remained in the top 30 cm of the sediments. This study illustrates that, under field conditions, near-surface colloid mobilization and transport occurred in Hanford sediments. [ABSTRACT FROM AUTHOR]

High methane dissolution capacity in a liquid is important for methane storage and transformation. In this work, methane solubility in different ionic liquids (ILs) was studied and was found associated with IL's structural and physical properties. In imidazolium-based ILs, ILs containing C-F and long alkyl chain showed high methane solubility mainly due to lower surface tension and molar density. Reducing the surface tension of solvent by adding 0.16 mol of trimethyl-1-propanaminium iodide (FC-134) with respect to [Bmim][NTf2] increased methane solubility by 39.3%. In situ high-pressure attenuated total reflection Fourier transform infrared spectroscopic results indicated a reversible process of methane dissolution in the ILs. The antisymmetric C-H stretching band of dissolved methane in ILs showed highly prominent rotational-vibrational bands with high intensity and narrow half-peak width compared to gaseous methane. Induced interaction between methane and IL resulted in increased dipole variation strength and reduced methane molecular symmetry. The constant antisymmetric C-H stretching peak at 3016.85 cm-1 revealed an unconstrained methane rotation in the stable physical and chemical environment of IL. Methane insertion into the IL's intranetwork space needs activation energy to overcome the interaction of cation-anion network. Kinetic analysis of methane in [Bmim][NTf2] and [Bmim][HSO4] at different temperatures indicated that methane dissolution in these two ILs was a reversible first-order and very weak endothermic process and that methane dissolution required high activation energy in ILs with stronger cation-anion interaction. [ABSTRACT FROM AUTHOR]

We present measurements as part of the Southern Oxidant and Aerosol Study (SOAS) during which atmospheric aerosol particles were comprehensively characterized. We present results utilizing a Filter Inlet for Gases and AEROsol coupled to a chemical ionization mass spectrometer (CIMS). We focus on the volatility and composition of isoprene derived organic aerosol tracers and of the bulk organic aerosol. By utilizing the online volatility and molecular composition information provided by the FIGAERO--CIMS, we show that the vast majority of commonly reported molecular tracers of isoprene epoxydiol (IEPOX) derived secondary organic aerosol (SOA) is derived from thermal decomposition of accretion products or other low volatility organics having effective saturation vapor concentrations <10-3 pg m-3. In addition, while accounting for up to 30% of total submicrometer organic aerosol mass, the IEPOX-derived SOA has a higher volatility than the remaining bulk. That IEPOX-SOA, and more generally bulk organic aerosol in the Southeastern U.S. is comprised of effectively nonvolatile material has important implications for modeling SOA derived from isoprene, and for mechanistic interpretations of molecular tracer measurements. Our results show that partitioning theory performs well for 2-methyltetrols, once accretion product decomposition is taken into account. No significant partitioning delays due to aerosol phase or viscosity are observed, and no partitioning to particle-phase water or other unexplained mechanisms are needed to explain our results. [ABSTRACT FROM AUTHOR]

Ionic liquids have been widely studied as effective reaction media for the conversion of glucose or cellulose to 5-hydroxymethhylfurfural (5-HMF). However, the recovery of 5-HMF from ionic liquids, typically carried out by extraction, has been encountered with very low extraction efficiency, which limited the reusability of the solvents. Through this work, based on the model biphasic system that consists of 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) as the ionic liquid phase and methyl isobutyl ketone (MIBK) as the extractant phase, the dominant force that suppresses the extraction efficiency of 5-HMF was identified as being the strong hydrogen bonding between 5-HMF and [BMIM]Cl. Solvent mediation with functional promoters have been established as a new strategy to shift this force, resulting in improved extraction efficiency of 5-HMF from the ionic liquid. For example, with ethanol as a promoter, the distribution coefficient of 5-HMF was about 10 times higher than that without a promoter. [ABSTRACT FROM AUTHOR]

We report on the magnetotransportproperties of chemical vapordeposition grown films of interconnected Bi2Te3nanoplates. Similar to many other topological insulator (TI) materials,these granular Bi2Te3films exhibit a linearmagnetoresistance (LMR) effect which has received much recent attention.Studying samples with different degree of granularity, we find a universalcorrelation between the magnitude of the LMR and the average mobility(⟨μ⟩) of the films over nearly 2 orders of magnitudechange of ⟨μ⟩. The granularity controlled LMReffect here is attributed to the mobility fluctuation induced classicalLMR according to the Parish–Littlewood theory. These findingshave implications to both the fundamental understanding and magnetoresistivedevice applications of TI and small bandgap semiconductor materials. [ABSTRACT FROM AUTHOR]

EfficientCO2capture by chemical absorption is currentlygaining interests for the control greenhouse gas emissions. In thiswork, a nonaqueous process was developed to regenerate CO2below 373 K by removing methanol first after the hybrid solventof monoethanolamine (MEA) and methanol had absorbed CO2. A model was accordingly developed to analyze the performance ofthe desorption process. Experiments were performed to determine themissing reaction kinetics of nonaqueous solvent regeneration of CO2to help develop the model. The predicted gas concentration,axial velocity, energy consumption, and desorption efficiency agreedwell with the stripper experimental data. A parametric analysis wasconducted to investigate the effects of temperature, pressure, leansolvent loading, gas/liquid ratio, packing, and internals on the energyconsumption and desorption efficiency. All analyses were performedunder three defined desorption conditions: N2, methanolvapor, and steam as purge gases. Major energy savings were clearlyidentified because of feasible desorption temperatures below 373 Kunder nonaqueous desorption conditions. N2purge gas desorptionconditions offered the minimum energy consumption of 2.28 GJ/t, being24% below the typical value of 3.0 GJ/t. Additionally, it was foundthat the nonaqueous environment improved the desorption efficiencyby 10% compared to that obtained by typical aqueous solution regeneration. [ABSTRACT FROM AUTHOR]

Weperformed molecular dynamics (MD) simulations on multiaminesolutions of CO2capture to optimize the conventional aminesolvents (MEA, MDEA, DEA, AMP, and TEA). A synergy molecular dynamicsmodel (SMD) was developed for the CO2and amine solutions,in which the molecular synergy number (MSN) was introduced to quantifyinteractions between diffusion and molecule motion. The SMD modelinvolved with the force field was validated with experimental datafrom CO2, amine, and water systems. The best synergy forthe MDEA-DEA-TEA system was achieved at the ratio of 3:1:1, with aminimum MSN being 3.89. The overall synergy in ternary amine systemswas found to be better than that in quaternary and quintuple aminesystems. Several optimized multiamine solution systems were identified.The MDEA-DEA-TEA solution could simultaneously provide better diffusivityand less drag force with mass transfer coefficient being 33.33 % higherthan that of AMP. The MEA-MDEA-DEA-TEA solution could improve CO2transport by increasing 18 % of diffusivity when varyingthe ratio from 1:1:1:1 to 2:1:1:1. All of the results above provideda benchmark to optimize the amine mixing solution design for CO2capture. [ABSTRACT FROM AUTHOR]

Spinel ferrite magnetic nanoparticles,MnFe2O4, NiFe2O4, andCoFe2O4, were synthesized and used as gas-phaseadsorbents for the removalof cyanogen chloride from dry air. Fixed-bed adsorption breakthroughexperiments show adsorption wave behavior at the leading edge of thebreakthrough curve that is not typical of physically adsorbed species.Fourier transform infrared spectroscopy (FTIR) results indicate thatCK is reacting with the spinel ferrite surface and forming a carbamatespecies. The reaction is shown to be a function of the hydroxyl groupsand adsorbed water on the surface of the particles as well as themetallic composition of the particles. The surface reaction decreasesthe remnant and saturation magnetism of the MnFe2O4and CoFe2O4particles by approximately25%. [ABSTRACT FROM AUTHOR]

Two novel coordination polymers with formulas CoL1·3H2O [1, L1=3,3′-((1,7-dioxa-4,10-diazacyclododecane-4,10-diyl)bis(methylene)dibenzenecarboxylate] and Co2L2(H2O)2·2(H2O) [2, L2= 5,5′-((1,7-dioxa-4,10-diazacyclododecane-4,10-diyl)bis(methylene))diisophthalate] were synthesized, where one Co(II) ion coordinatesthe crown-4 moiety of the ligand. Compound 1crystallizesin the space group C2 as an infinite two-dimensionalchiral layered coordination network with a tetragonal 44sqlnet topology. The structural unit consists of thecoordinated Co(II) ion and the deprotonated ligand. The Co(II) ionis 6-coordinate with two nitrogen atoms and two oxygen atoms of thecrown 1,7-diaza-12-crown-4, and two carboxylate oxygen atoms fromneighboring ligands, and exhibits a highly distorted octahedral geometry.Compound 2crystallizes in the monoclinic space group P21/nas a triply interpenetrating3D network with the uncommon sqc528/dmd system, the firstcoordination polymer with a 3-fold interpenetrating dmd topology.It exhibits two distinct Co(II) ions. One is in the center of thecrown-4 along with two cis-coordinated water moleculesin a highly distorted octahedral geometry; the other is 4-coordinatewith tetrahedral geometry and a node in the framework. Weak antiferromagneticinteractions exist between the cobalt centers in both compounds. [ABSTRACT FROM AUTHOR]

Magnetic cobalt spinel ferrite nanoparticles coated with biocompatible polygalacturonic acid were functionalized with ligands specific for targeting expressed EphA2 receptors on ovarian cancer cells. By using such magnetic nanoparticle-peptide conjugates, targeting and extraction of malignant cells were achieved with a magnetic field. Targeting ovarian cancer cells with receptor specific peptide-modified magnetic nanoparticles resulted in cell capture from a flow stream in vitro and from the peritoneal cavity of mice in vivo. Successful removal of metastatic cancer cells from the abdominal cavity and circulation using magnetic nanoparticle conjugates indicate the feasibility of a dialysis-like treatment and may improve long- term survival rates of ovarian cancer patients. This approach can be applied for fighting other cancers, such as leukemia, once the receptors on malignant cells are identified and the efficacy of targeting ligands is established. [ABSTRACT FROM AUTHOR]

In this paper, we have demonstrated that P-type dehydrated nanotube titanic acid (DNTA) can significantly enhance hole injection and transport in holes-only transport devices. In the low field region, the dominant conduction mechanism is injection limited. This gradually transitions to space charge limited current via trapped charge limited current with increasing applied voltages. Through fabricated and characterized organic light-emitting diodes (OLEDs) and by using a DNTA−poly(vinylcarbazole) (PVK) nanocomposite as the hole transport layer, we found that the performance of these devices was greatly improved with a higher luminance, an enhanced efficiency, and a lower turn-on voltage. [ABSTRACT FROM AUTHOR]

Examines the chromatographic separation and characterization of hydrolyzed chromium III species. Use of capillary electrophoresis in isolating the oligomers and chromium species; Complexity of chemical behavior; Measurement of proton acidities.