Miracle-dz/UniFAR-FTUs huggingface dataset:
A Critical Evaluation of NOx Modeling in a Model Combustor

Reliable NOx modeling depends on the accurate prediction of both velocity and temperature fields. The velocity and temperature fields of a propane diffusion flame combustor, with interior and exterior conjugate heat transfers, were first numerically studied. The results from three combustion models, together with the re-normalization group (RNG) k-e turbulence model and the discrete ordinates radiation model are discussed, and compared with comprehensive experimental measurements. The flow patterns and the recirculation zone length in the combustion chamber are excellently predicted, and the mean axial velocities are in fairly good agreement with the experimental data for all three combustion models. The mean temperature profiles are fairly well captured by the probability density function (PDF) and eddy dissipation (EDS) combustion models. However, the EDS-finite-rate combustion model fails to provide an acceptable temperature field. Based on the acceptable velocity and temperature fields, a number of NO modeling approaches were evaluated in a post-processing mode. The partial-equilibrium approach of O and OH radical concentrations shows a significant effect on the thermal NO formation rate. In contrast, the prompt NO, the NO re-burn mechanism and the third reaction of the extended Zeldovich mechanism have negligible effects on the overall NO formation in the present study. This study indicates that the semi-empirical, post-processing NO model can provide valuable NO simulations as long as the velocity and temperature fields are adequately predicted.Copyright © 2004 by ASME
Speciated PM10 Emission Inventory for Delhi, India

Emission inventories can serve as a basis for air quality management programs. The focus has been mainly on building inventories for criteria pollutants including particulate matter (PM). Control efforts in developing countries are mostly limited to total suspended particles (TSP) and/or PM10. Since the adverse effects of PM10 depend on its chemical composition, it is important to control emissions of toxic species. The first step is to identify key pollution sources and estimate quantities of various chemical species in emissions. This paper presents a speciated PM10 emission inventory for Delhi, the capital and one of the most polluted cities in India. An established PM10 inventory for Delhi in conjunction with source profiles was used to estimate emissions of major PM10 components including organic and elemental carbon (OC and EC, respectively), sulphates (SO4 2– ), and nitrates (NO3 – ), as well as selected toxic trace metals (i.e., Pb, Ni, V, As, and Hg), some of which are subject to India’s National Ambient Air Quality Standards (NAAQS). For the base year of 2007, emission estimates for PM10 mass, OC, EC, SO4 2– , and NO3 –
Electrochemical properties and morphological evolution of pitaya-like Sb@C microspheres as high-performance anode for sodium ion batteries

Pitaya-like Sb@C microspheres are prepared successfully by facile aerosol spray drying synthesis. Structural and morphological characterizations reveal that the Sb@C microspheres have a uniform pitaya-like structure, with well crystallized Sb nanoparticles embedded homogeneously in the carbon matrix. The Sb@C microsphere electrodes exhibit high Na storage capacity of 655 mA h g−1 at C/15 with excellent cyclability (93% of capacity retention over 100 cycles), as well as remarkable rate capability. Also, the morphological evolution of the Sb@C microspheres is unravelled to account for its excellent electrochemical performance, caused by maintenance of the pitaya-like configuration during cycling. This structural stability guarantees tight contact of Sb with carbon buffer, as well as uniform distribution of Sb to balance the localized mechanical stress, ensuring excellent electrochemical performance. The structural design and synthetic method reported in this work may provide an effective way to stabilize electrochemical performance of Na-storable alloy materials and therefore provide a new prospect for creation of cycle-stable alloy anodes for high capacity Na-ion batteries.
Role of sulfate reduction and methane production by organic carbon degradation in eutrophic fjord sediments (Limfjorden, Denmark)

The anaerobic mineralization of buried organic matter through sulfate reduction and methanogenesis was studied in 2‐m‐long piston cores of organic‐rich, silty‐clay sediment from two sites in Limfjorden, Denmark. An extended sulfate‐methane transition (SMT) zone was found at 1–1.5‐m sediment depth, accompanied by peaks in sulfide (4–6 mmol L−1) and high dissolved inorganic carbon (30–50 mmol L−1). Pore‐water acetate concentrations were 2‐10 µmol L‐1. 14C‐acetate was oxidized to 14CO2 in the sulfate zone and reduced to 14CH4 at and below the SMT. CO2 reduction was the predominant pathway of methanogenesis below the sulfate zone. Sulfate reduction rates (SRRs) determined by 35S tracer experiments decreased with depth throughout the sulfate zone from > 100 nmol cm−3 d−1 near the sediment surface to < 1 nmol cm−3 d−1 at depth. The depth trend of rates was equally well described by a power law function and a reactive continuum model. Only a small percentage of the total 35S‐SRR was due to anaerobic oxidation of methane. In contrast, diffusion‐reaction modeling of pore‐water sulfate indicated that sulfate reduction was insignificant throughout the sulfate zone and that most of the activity occurred at the SMT. A comparison of the burial flux of organic carbon below the sulfate zone and the returning flux of methane indicated that the diffusion modeling of pore‐water sulfate strongly underestimated in situ SRRs, whereas the 35S data may have overestimated the rates at depth. Modeled and measured SRR could be reconciled provided that bioirrigation reached to at least 20–40‐cm sediment depth, which appears realistic given the predominant burrowing polychaete fauna.
Physiochemical Properties of Hydroxy Mixed Ether HMEn Surfactants and their Interaction with Sodium Dodecyl Sulfate SDS

Abstract This paper is focused on the phase behavior, interaction with anionic surfactant sodium dodecyl sulfate SDS, adsorption and wetting investigations of new hydroxy mixed ether nonionic surfactants HMEn. The phase diagrams of (0.1–100) %wt of HMEn (n-value is the ethoxylation number EO) at the temperature range 20–100°C have shown that the increasing of n-value raises the cloud boundary toward higher temperature. Remarkable result was obtained from the interaction between SDS and HMEB, at which the mixed system exhibits a unique homogeneity and a liquid crystal phase formation. Macroscopically, the liquid crystal region was found when the SDS concentration range between 8 and 24 mM mixed with 10% wt HMEB. The interaction between HMEn and mica was also investigated using atomic force microscopy AFM and a pronounced adsorption of HMEn on mica was observed. Moreover, contact angle results reveal that glass substrate shows strong wettability of HMEn surfactant solutions compared with polyethylene PE and polymethylmethaacrylate PMMA substrates. This wettability however also decreases with EO number.
Physical mechanisms of negative-bias temperature instability

We report first-principles calculations that elucidate the mechanisms that underlie key features of negative-bias temperature instability (NBTI). We show that the depassivation of Si–H bonds by protons released in the Si substrate is consistent with the observed increase in interface-trap density. The calculated activation energy of 0.36eV is in excellent agreement with observations for long stress times. Adequate amounts of hydrogen, needed to initiate depassivation, are likely to exist in the substrate, trapped in complexes with dopants. The role of holes in the H release mechanism is identified. Finally, we explain how the above mechanisms can account for various experimental NBTI observations.
An XPS study of indium through the melting point

An XPS study has been carried out on indium in both the solid and liquid states. Very small binding energy shifts (0.2 eV) have been detected for the core peaks and Auger transitions. The plasmon energy associated with the 3d3/2 peak has been carefully measured and a shift found to a lower energy in the liquid state. These results agree with the view that the solid state local order is retained in the liquid state.
THREE-DIMENSIONAL NUMERICAL SIMULATION FOR UNDERSTANDING THE FRINGE-FIELD EFFECT ON THE DYNAMIC BEHAVIOR OF LIQUID CRYSTAL

A three-dimensional numerical study for understanding the fringe-field effect on the dynamic behavior of liquid crystal is presented. Our three-dimensional numerical simulator (TechWiz LCD) is based on the FEM (finite element method) formulation of Ericksen-Leslie equation, flow equation, and Laplace equation. Since our FEM solver has a fully unstructured mesh generator, it is possible to investigate the dynamic performance of any mode of LC cell with an arbitrarily shaped electrode structure including a chevron-type LC cell. In this paper, we report our preliminary result on the simulation of the dynamic behavior of the fringe-filed switching (FFS) mode LC cell that is designed for the fast response and wide viewing angle. The simulated dynamic response of the director distribution for the FFS-mode LC cell is also compared with experimental observations. The simulation reveals that most of the directors over the LC cell experience horizontal rotations despite the existence of both the vertical and the horizontal electric fields in the LC cell.
SIMULATION OF AN OPERATIONAL AMINE BASED CO2 REMOVAL PLANT AS AN EXAMPLE OF CO2 CAPTURE AT COAL-FIRED POWER PLANTS

Among many understudy CO2 capture technologies, amine scrubbing is the most promising near term strategy. In this article, Kent/Eisenberg, Lee/ Mather and Electrolyte Non Random Two Liquid model (E-NRTL) models were utilized to simulate an operational unit based on monoethanolamine (MEA) as solvent and 18 % molar CO2 feed gas. Simulated results are compared to plant data. Important parameters like temperature and pH are traced at absorption and stripping towers and other process equipments. Secondly use of MEA, DGA, MDEA, DEA and DIPA and their mixtures for CO2 Scrubbing were simulated. Our study shows that diglycolamine (DGA) and DGA/MEA mixtures can outperform MEA in energy consumption, tower diameter and circulation rate for flue gases containing high CO2 content. The results of our study can help lowering both capital and operational expenses of CO2 capture.
The effect of humidity on probe-sample interactions in near-field scanning optical microscopy

The shear force damping between a tapered near-field probe and a well-cleaned glass sample depends on the humidity. A slow decay region, up to few hundred A, appeared in the onset of the damping curves as the humidity increased. This humidity-dependent interaction force is of viscous type and ∼0.1 nN. The frictional coefficient increases faster than the estimation from Newton’s law of viscosity as the probe and sample distance decreases. This is attributed to the enhancement of viscosity in thin water layer.
Hydrogen storage on graphene using Benkeser reaction

Recently, graphene has received great attention as potential hydrogen storage media. Here, we report a new route to store/chemisorb high content of hydrogen on graphene by employing Benkeser reaction. Graphene nanosheets are produced via a soft chemistry synthetic route involving oxidation of graphite using Improved method, ultrasonic exfoliation, and chemical reduction by using hydrazine with overnight heat treatment. Graphene is hydrogenated by using lithium in ethylenediamine under Benkeser reaction at atmospheric pressure and 30 °C. Benkeser reaction overcomes the liquid ammonia handling and produced multiple layer of graphene attached to the hydrogen atoms. High‐resolution transmission electron microscopy and selected area electron diffraction analysis confirm the ordered graphite crystal structure of graphene and reveal the rough, corrugated hydrogenated graphene layers attached by hydrogen atoms. Fourier transformation infrared spectroscopy analysis confirms that hydrogen adsorption occurs at all the ortho, meta, and para positions of aromatic graphene. The degree of hydrogenation of graphene estimated by thermogravimetric analysis reveals 14.67% (weight %) hydrogen storage, which is considerably higher than the earlier reported values of percentage storage achieved using various physisorption and chemisorption techniques. Copyright © 2014 John Wiley & Sons, Ltd.
Bis(phosphinimino)methanides as Ligands in Divalent Samarium Chemistry: Synthesis, Structures and Catalysis

The reaction of K{CH(PPh2NSiMe3)2} with samarium diiodide in a 1:1 molar ratio in thf affords the corresponding divalent samarium complex [{(Me3SiNPPh2)2CH}Sm(μ-I)(thf)]2 (1), whereas treatment of K{CH(PPh2NSiMe3)2} with samarium diiodide in a 2:1 molar ratio in thf gives the homoleptic complex [{(Me3SiNPPh2)2CH}2Sm] (2). When 1 is treated with KNPh2 in toluene in a 2:1 molar ratio the mixed dimeric compound [({(Me3SiNPPh2)CH}2Sm)2(μ-I)(μ-NPh2)] (3) is obtained. The single-crystal X-ray structures of all these complexes have been determined. [{(Me3SiNPPh2)2CH}Sm(μ-I)(thf)]2 has also been successfully used as a catalyst for the polymerization of ϵ-caprolactone. Good activities and molecular masses are observed with this catalyst. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Characterization of Polycyclic Aromatic Hydrocarbons (PAHs) Present in Smoked Fish from Ghana

The study was conducted to determine the levels of Polycyclic Aromatic Hydrocarbons (PAH) in smoked Scomba japonicus sampled from some Ghanaian markets. By way of preparation, smoked fish comes into contact with smoke or extremely high temperature which are potential sources of PAH generation. Levels of 20 individual PAHs including acenaphthene, acenaphtyelene, anthanthrene, anthracene, benz(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(e)pyrene, benzo(ghi)perylene, benzo(j)fluoranthene, benzo(k)fluoranthene, chrysene, cyclopenta(cd)pyrene, dibenzo(ah)anthracene, fluoranthene, fluorene, indeno(1, 2, 3-cd)pyrene, naphthalene, phenanthrene and pyrene were determined in 34 smoked fish samples using gas chromatographic techniques with flame ionization detector. Benzo(a)pyrene, which is one of the very few PAHs for which a legal limit exists in different types of food matrices inaddition to other high molecular weight PAHs suspected to be carcinogens, were detected in most samples.
A new method for the generation of α‐nitrosoolefins from ketooximes and its application to the synthesis of 5,6‐dihydro‐4H‐1,2‐oxazine derivatives

Reaction of ketooximes containing α-methylene group with chloramine-T followed by treatment with tri-ethylamine leads to the formation of α-nitrosoolefins via α-nitrosochloride, which can react in situ intermol-ecularly with olefinic compounds to produce 5,6-dihydro-4H-1,2-oxazine derivatives in good yield.
Optical properties of metal nanoparticle coated silica spheres: a simple effective medium approach

The preparation of gold particle coated silica microspheres is described and the optical absorption spectra for various surface coverages of gold particles are presented. Onion-shell particles with the structure silica-gold-silica are also described. An effective medium model is used to quantify the surface plasmon shifts observed in such particles, which predicts the shifts in surface plasmon band for both solvent refractive index and surface coverage. The resultant microspheres exhibit absorption spectra resembling those of the isolated nanocrystals. However they possess extinction cross-sections orders of magnitude higher than the nanocrystals and can be centrifuged and redispersed more easily than the parent nanocrystals. The same effect can be obtained by coating silica spheres with gold nanorods, so that the plasmon absorption band can be tuned through the visible and NIR wavelength range. It is proposed that such micron-sized “nanoparticles” provide a practical means to amplify the unique optical properties of nanocrystals and make them more amenable to colloid processing.
BIODEGRADABLE HYPERBRANCHED POLYESTER: A NEW BUILDING BLOCK IN THE CONSTRUCTION OF MULTIFUNCTIONAL NANOPARTICLES AND NANOCOMPOSITES FOR TARGETED CANCER THERAPY AND IMAGING

Materials. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), 1,1'-Carbonyldiimidazole (CDI), N-hydroxysuccinimide (NHS), AZT (azidothymidine) and other chemicals were purchased from Sigma-Aldrich and used without further purification. Near Infra Red dyes (DiI - D282, DiD - D7757, and DiR - D12731) and 4', 6-diamidino-2- phenylindole (DAPI - D1306) were purchased from Invitrogen. The folate- receptor-overexpressing human lung carcinoma cell line A549 (CCL-185) and cardiomyocytes (H9c2) were obtained from ATCC. Instrumentation. Infrared spectra were recorded on a PerkinElmer Spectrum 100 FT-IR spectrometer. UV/Vis spectra were recorded using CARY 300 Bio UV/Vis spectrophotometer. Confocal images were taken on a Zeiss Axioskop 2 mot plus confocal microscope. Flow Cytometry experiments were performed using a BD FACS Calibur multipurpose flow cytometer system from BD Biosciences. MTT study has been done using the BIO-TEK Synergy HT multi-detection microplate reader. IVIS experiments were done on an IVIS 50 imaging system from Xenogen imaging technologies. Synthesis of 2-(4-hydroxy butyl)-malonic acid (4): 2-(4-acetoxy- butyl)-malonic acid diethyl ester (5.0 g, 18.25 mmol) was taken in a 100 mL round bottom flask containing methanol (50 mL) and stirred at room temperature for 2 min. To this we added NaOH (2.1 g, 54.74 mmol) in water (7 mL) and stirred at 90 o C for 8 h. The reaction mixture was brought to room temperature and acidified (pH 2-3) with the drop-wise addition of dilute hydrochloric acid at room temperature with constant stirring. To the concentrated reaction mixture chloroform (50 mL) was added and Argon gas was bubbled through the solution at 60 o C to remove excess HCl. The mixture was filtered and the filtrate was concentrated. This was then purified by column chromatography using 35% ethyl acetate in petroleum ether as eluent. Yield: 2.31 g (72%).
WATER QUALITY EVALUATION OF SMALL SCALE DESALINATION PLANTS IN THE GAZA STRIP, PALESTINE

The Gaza Strip is a highly populated, small area in which the groundwater is the main water source. During the last few decades, groundwater quality has deteriorated to a limit that the municipal tap water became brackish and unsuitable for human consumption in most parts of the Strip. To overcome this serious situation, the reverse osmosis (RO) technology is used to replace the tap water or to improve its quality. Several private Palestinian water investing companies established a small-scale reverse osmosis (RO) desalination plants to cover the shortage of good quality of drinking water in the whole Gaza Strip. The purpose of this paper is to investigate the chemical and bacteriological water qualities of different small scale of (RO) desalination companies in the Gaza Strip. The results of the chemical and bacteriological parameters were compared with the World Health Organization (WHO) standards. It was concluded that all chemical analyses of RO produced water are within the allowable WHO limits. Bact.
Preparation and properties of covalently cross-linked sulfonated poly(sulfide sulfone)/polybenzimidazole blend membranes for fuel cell applications

To improve the radical oxidative stability, a series of covalently cross-linked blend membranes have been prepared from a sulfonated poly(sulfide sulfone) with 80% degree of sulfonation (SPSSF80) and a polybenzimidazole with pendant amino groups (H2N-PBI) using glycidyloxypropyltrimethoxysilane (KH-560) and bisphenol A diglycidyl ether (BADGE) as cross-linkers. The resulting cross-linked membranes show increased tensile strength but slightly decreased elongation at break compared with the plain SPSSF80. The radical oxidative stability of the blend membranes is significantly improved due to the synergic action of the covalent cross-linking and the presence of the PBI component. For example, the cross-linked membrane with the composition of SPSSF80/H2N-PBI/KH-560 = 7/1/3 started to break into pieces after being soaked in Fenton’s reagent for 98 min, which is about 4 times longer than that (20 min) of the plain SPSSF50 (degree of sulfonation = 50%). The covalent cross-linking is also essential to suppress membrane swelling and to enhance membrane water stability. The KH-560-cross-linked blend membranes tend to show higher proton conductivities at low relative humidities than the BADGE-cross-linked one due to the hydrophilic silica network in the former. At fully hydrated state, the cross-linked membranes generally show high proton conductivities comparable with that of Nafion112®.
In situ measurement of growth kinetics of {100} KDP crystal faces in the presence of polyphosphate impurities

The face growth rate and critical supersaturation of {100} face were in situ measured using the laser‐polarization‐interference technique in the presence of potassium pyrophosphate, trimetric sodium phosphate and sodium hexametaphosphate impurities. The polyphosphate impurities inhibit the growth rate of prismatic faces. The face growth rate as a function of supersaturation at different impurity concentrations, as well as critical supersaturation as a function of impurity concentrations, was found in good agreement with a two‐dimensional nucleation model in the pure system and Kubota and Mullin's model in the presence of impurities. The average distance L between active sites available for impurity adsorption as well as the edge free energy was calculated. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Diffusion Coefficient of Germanium in Silicon

The germanium diffusion coefficients in Si and SiO2 are investigated by the use of secondary ion mass spectrometry (SIMS). The diffusion profiles are discussed in detail to obtain precise diffusion coefficients. The germanium diffusion coefficients in Si and SiO2 are measured as D = 7.55 × 103 exp (−5.08 eV/kT) cm2/s and D ≈ 8.9 × 10−3 exp (−3.9 eV/kT) cm2/s, respectively. Not only the activation energy but also the germanium diffusion coefficient in Si are very close to those of the Si self-diffusion.
Seedless, Surfactantless, High-Yield Synthesis of Branched Gold Nanocrystals in HEPES Buffer Solution

In this work, three-dimensional branched gold nanocrystals were produced at high yield by reacting an aqueous solution of chloroauric acid with a Good's buffer, HEPES, at room temperature. This particular method of preparation was scalable to gram-quantity. The branched nanocrystals containing one to eight tips were stable at room temperature and could be stored as a powder after freeze-drying. They were, however, unstable at higher temperatures and transformed into spherical particles upon boiling. The formation of the branched gold nanocrystals was kinetically controlled, as shown by the dependence of shapes on temperature and precursor salt concentration. The growth of branched gold nanocrystals in the HEPES buffer was monitored by microscopic and spectroscopic techniques, allowing the detection of several key intermediates in the growth process. Piperazine in HEPES molecule was identified as the principal moiety responsible for forming highly branched Au nanocrystals in the HEPES buffer.