Miracle-dz/UniFAR-FTUs huggingface dataset:
Electrodialysis in an Integrated NF/ED Process for Water Recovery in the Leather Industry

Electrodialysis (ED) was assessed for integration in a nanofiltration NF/ED sequence for water reuse in the leather industry. Two ED feeds composed of different model solutions were used: Model Solution FED1, which is a surrogate of a nanofiltration permeate generated by the NF processing of a biologically treated leather effluent, and Model Solution FED2, which has the same salt concentration as FED1 but with an organic matter content that is approximately ten times higher. The electrodialysis experiments were carried out in a five-compartment bench cell using cationic and anionic membranes HDX 100 and HDX 200. The final product water, with a conductivity ranging from 3.28 to 3.67 mS cm−1, can be reused as process water for beamhouse operations. With respect to chloride and COD parameters, the ED product water meets the requirements of process water, even for dyeing operations. An alkaline membrane cleaning process for fouling removal was also tested for the membranes using Model Solution FED2. The cleaned membranes were evaluated in terms of visual aspect, polarization curves, TGA, and SEM/EDS analysis. The results obtained with the cleaned membranes were very similar to those obtained with the new ones in ED experiments with Model Solution FED2.
Influence of transverse rotating magnetic field on enhancement of solid dissolution process

The main objective of this work is to study the effect of transverse rotating magnetic field (TRMF) on the enhancement of solid dissolution process in the novel type reactor (TRMFR). The application of magnetically driven fluidization (MDF with homogeneous and heterogeneous systems) on mass transfer process is presented. A study of the effect of ferromagnetic particles content on solid–liquid mass transfer has been made. The experimental investigations are provided for the explanation of the influence on the dissolution process of a solid body to surrounding its dilute solution in a novel type reactor with the ferromagnetic particles suspended. The mass transfer coefficient is calculated from a kinetic equation and correlated in the relationship including standard and magnetic dimensionless numbers. The overall enhancements due to TRMF and MDF were compared. Unique correlating relations were obtained to generalize the experimental database. © 2009 American Institute of Chemical Engineers AIChE J, 2010
Auger recombination in silicon at low carrier densities

We have discovered a simple chemical preparation method for silicon which virtually eliminates surface recombination. This has enabled us to rapidly survey wafers from many different boules in order to identify those in which bulk (defect assisted) Shockley–Read–Hall recombination happens to be unusually low. Thus, having minimized the two major sources of electron‐hole recombination, we find that Auger recombination becomes dominant, even at carrier densities as low as 3×1015/cm3. The Auger coefficient we observe is significantly larger than the value extrapolated down from high density.
Effect of Absorbing Type Aerosols (Soot) and Vertical Distribution of Aerosols on Direct Aerosol Radiative Forcing; A Modeling Study

In the present study, our aim is to quantify the effect of absorbing type aerosols and vertical distribution of aerosols in aerosol radiative forcing estimations and also in understanding the vertical profile of heating rates. The radiative forcing values were calculated for an aerosol optical depth of 0.3 at 0.5 μm. The asumed single scattering albedo changes from 0.75 to 0.95 due to changing of absorbing type arosols and the asumed elevated aerosol contribution is ~ 60% to totla aerosol optical depth. We have observed large variation in atmospheric radiative forcing from +27.71 Wm to +41.15 Wm due to change in absorbing aerosols. Although there was less difference found in radiative forcing at the surafce and top of the atmosphere but significant difference found in atmospheric forcing due to variation of vertical distribution of aerosols for the averaged single scatterig albedo. These observed results are interpreted in the context of current understanding of aerosol radiative forcing.
Flotation Separation of SiC from Wastes in the Silicon Wafer Slicing Process

シリコン単結晶からのシリコンウエハーのスライシング工程では，SiC粒子をラッピングオイルに混合した潤滑油を用いてワイヤソーによってシリコンが切断されている．シリコン単結晶をスライシングした後，SiCと削られたSiの混合物を含む研削廃液が発生する．SiCおよびSiの粒子径は，それぞれ約10 µmおよび約1 µmであり，これらの重量比は9 : 1程度である．研削廃液中の粒子は，油をフィルタープレスで除去した後に焼成処理すると，SiCとSiO2を含む混合物になる．廃棄物の減容化や環境上の観点から，有価物であるSiCをSiO2から分離・再生することが望ましい．上述の目的に対しては，浮選法が適用できる．陽イオン性界面活性剤であるドデシルトリメチルアンモニウムクロライドおよびトリメチルオクチルアンモニウムクロライドを界面活性剤として用いた．SiCおよびSiO2粒子上への界面活性剤の吸着量が測定された．ドデシルトリメチルアンモニウムクロライド存在下でpH，ガス流速，浮選時間を変化させて，SiCとSiO2の浮選挙動を調べた．あわせて，粗選工程，精選工程および清掃選工程を含む一連の浮選プロセスを適用してSiCの純度と収率について検討を行った．一連の浮選プロセスで得られるSiCの純度および収率は，それぞれ99. 7%および96. 7%であった．
Design of disk molecular pumps for hybrid molecular pumps

In recent years, the various types of hybrid molecular pumps combining a molecular drag pump (MDP) with a turbomolecular pump (TMP) have been developed in order to raise their pumping throughput and operating pressure. Some of them have been put on the market. In this article the pumping performances of the disk MDP, whose pumping channels are cut on a rotating disk, were calculated using a new model based on the Monte Carlo method. The relationship between the pump performance to the structural parameters was studied. The above pumping performance is also compared with that of the pumps having channels on stationary disks. When a pump is constructed in a series of two stages, the pumping speed and the compression ratio of the present pump for nitrogen gas increases by 35% and 64%, respectively, as compared with the previous type. It is believed that the pump having channels on the rotating disk has both kinds of pumping actions. Hence, it possesses the advantages of both MDP and TMP.
Desempenho da modelagem cinemática do escoamento superficial para chuvas intermitentes em solos com cobertura morta

Mulching is an important management practice for overland flow control. Antecedent soil moisture conditions, rainfall patterns, and soil cover play an important role in the detachment and transport of soil particles and runoff generation. This study aimed to investigate the performance of kinetic wave model in simulating overland flow from multiple step intermittent rainfall events, considering distinct mulch densities. Laboratory experiments were conducted using a soil flume and rainfall simulator adopting three soil cover scenarios: i) Bare soil; ii) Low mulch cover density of 2 t ha-1; and iii) High mulch cover density of 4 t ha-1. The laboratory experiments clearly show that mulch strongly affects surface runoff. Intermittency and characteristics of sequential rainfall events also influenced such process. The kinematic wave model predicted efficiently surface runoff, presenting Nash-Sutcliffe coefficients higher than 0,75 and determination coefficients higher than 0,90, for all cover conditions, when initial soil moisture was high.
Methanol to Olefin over Ca-Modified HZSM-5 Zeolites

A series of HZSM-5 zeolites modified with various Ca loadings were prepared by an incipient impregnation technique and characterized by Fourier transform infrared spectra of adsorbed pyridine and temperature-programmed desorption of NH3 and CO2. Methanol to olefin (MTO) over Ca-modified HZSM-5 zeolites was performed in a flow-type fixed bed reactor. The results indicated that Ca modification increased both the catalytic stability and the light olefin selectivity. However, an excess Ca loading resulted in an inferior catalytic performance. Hence, there was an optimal Ca loading for a specific HZSM-5, and the thus prepared Ca/HZSM-5 had little free Bronsted acid sites and presented the best catalytic performance of MTO. A possible mechanism for MTO involving acid−base centers on Ca-modified HZSM-5 zeolites has been suggested on the basis of the results obtained.
Origin of Enhanced Reducibility/Oxygen Storage Capacity of Ce1-xTixO2 Compared to CeO2 or TiO2

We determine chemical origins of increase in the reducibility of CeO2 upon Ti substitution using a combination of experiments and first-principles density functional theory calculations. Ce1-xTixO2 (x = 0.0−0.4) prepared by a single step solution combustion method crystallizes in a cubic fluorite structure, confirmed by Rietveld profile analysis. Ce1-xTixO2 can be reduced by hydrogen to a larger extent compared to CeO2 or TiO2. Temperature programmed reduction of CeO2, TiO2, Ce0.75Ti0. 25O2 and Ce0.6Ti0.4O2 up to 700 °C in H2 gave CeO1.96, TiO1.92, Ce0.75Ti0. 25O1.81, and Ce0.6Ti0.4O1.73, respectively. An extended X-ray absorption fine structure (EXAFS) study of mixed oxides at the Ti K-egde showed that the local coordination of Ti is 4:4, with Ti−O distances of 1.9 and 2.5 A, respectively, which are also confirmed by our first-principles calculations. Bond valence analysis of the microscopic structure and energetics determined from first principles is used to evaluate the strength of binding of different o.
Comparative Study of Impinging Jet Array Heat Transfer on a Flat Plate Cooled by Superheated Steam and Air

In modern gas turbine, using superheated steam to cool the vane and the liner of combustion chamber is a promising alternative to traditional compressor air. Infrared camera was applied to measure the spatial distribution of the impingement heat transfer coefficient on a flat plate cooled by superheated steam and air in this paper. The experimental study revealed the distribution of local heat transfer coefficients over a flat plate cooled by steam and air in an array of 3×5 impinging jets module. Results showed that the impingement cooling heat transfer is enhanced by the increase of mass flow rate, and the superheated steam cooling could improve area averaged heat transfer performance 35.3∼83.0% more than air cooling in the same mass flow rate conditions in the experiment. The influence of the jet-to-plate spacing ratio (Zn/d) and the jet-to-jet spacing ratio (Yn/d) on heat transfer were also investigated. It was concluded that the heat transfer is enhanced with the increase of Yn/d or the decrease of Zn/d based on the same area. Furthermore, three-dimensional and steady state computations had been carried out for experimental operating conditions. The Numerical results and experimental data have good agreements with each other for both the area averaged Nu and the local Nu, so results of the numerical model are expecting reliable. Results based Numerical models showed detailed characteristics of the distribution of the velocity and turbulence level, which revealed underlying mechanisms of pressure loss and flow structure for steam cooing and air cooling respectively. © 2014 ASME
Thermal and spectral stability of fluorescent copolymers containing tetraphenylthiophene-quinoline unit

Fluorescent alternative copolymers containing tetraphenylthiophene-quinoline (TP-Qu) moiety were synthesized from Friedlander reaction between o-aminoketone and acetyl groups. With the wholly aromatic-quinoline chain structure, the alternative donor–acceptor copolymers of PTPQu and PTPTPQu are rigid materials with high glass transitions (Tg = 245 and 295 °C, respectively) and with high thermal stability (with ≤2% weight loss at 500 °C). The multiple phenyl pendant rings inherited PTPQu and PTPTPQu copolymers with good solubility in common organic solvents, which facilitate the easy fabrications of light-emitting diode (LED) devices. CV study resulted in the reversible Eox/onset values of 0.78 and 0.75 V for the PTPQu and PTPTPQu copolymers, respectively. With high quantum yields (ϕFs, = 0.59 for PTPQu and 0.74 for PTPTPQu) in the film states, the two copolymers and their devices exhibit stable photoluminescence (PL) and electroluminescence (EL) spectra, respectively, on change of annealing temperatures to at least higher than 250 °C. After annealing at 250 °C (or 300 °C), no change was observed in the respective PL and EL spectra of PTPQu (or PTPTPQu) copolymers. The results indicate that alternative copolymers containing donor–acceptor TP-Qu unit are promising candidates for LEDs with high efficiency and spectral stability. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
CHARGE-TRANSPORT POLYMERS FOR LIGHT-EMITTING-DIODES

Electron transport polymers containing aromatic oxadiazole side chain chromophores have been designed and synthesized. They have been found useful for improving the quantum efficiency, lowering the turn-on -voltage, and enabling the use of the more stable aluminum cathode in the fabrication of polymer LEDs. As the oxadiazole units are chemically bound to the polymer chain, rather than being simply dispersed in a polymer matrix, the materials are expected to exhibit long-term morphological stability. The synthesis and several different applications are presented.
Sub- and supersonic COILs driven by a jet-type singlet oxygen generator

The experimental results of study of sub- and supersonic chemical oxygen-iodine lasers (COIL) based on the jet type singlet oxygen generator are presented. The progress in the high pressure jet type singlet oxygen generators allowed to develop the compact highly efficient COIL. The different types of the mixing schemes were tested in supersonic COIL based on the high pressure jet singlet oxygen generator. The preliminary cooling of the active medium by mixing of oxygen with the cold buffer nitrogen gas results in high efficiency operation of the small scale COIL with subsonic and supersonic gas flow in the laser cavity. In COIL with the fast axial gas flow the chemical efficiency more than 20% was achieved.
Chromium Ion Pair Interactions in the Paramagnetic Resonance Spectrum of Ruby

The paramagnetic resonance spectrum of Cr3+ pairs in ruby which interact via exchange and dipolar forces have been studied at 15.74 kMc in the temperature range 1.2° to 700°K. Theoretical analysis predicts and experiments confirm that relatively distant neighbors with negligible exchange coupling give rise to resonance lines which cluster around isolated Cr3+ ion lines. Spin pairs coupled through exchange forces large as compared to the Zeeman or crystalline field energies give rise to lines that cluster around magnetic field values different from those for isolated Cr3+ lines. Exact calculations on an IBM 704 computer are used to assign lines in a given cluster to various neighbor pairs. This assignment together with the temperature dependence of the line intensities are used to determine the exchange forces. For nearest neighbors the exchange constant is 390±50 cm−1 while the 3rd through 11th neighbor shells have exchange interactions of order 1 cm−1. Spin-lattice relaxation is discussed for pairs coupl.
Modeling the Onset of Asphaltene Flocculation at High Pressure by an Association Model

Abstract A new thermodynamic model was developed to calculate the onset of flocculation in crude oil systems similarly to the liquid-liquid equilibrium of polymer solutions. The key concept of the model is that asphaltene self-association leads to a polydisperse system of associates characterized by a size distribution function. Using continuous thermodynamics the mass action law is applied to the association equilibrium and an analytical expression for the size distribution function is derived. In contrast to polymer thermodynamics this distribution function depends on temperature, pressure, and concentration. For modeling the high pressure equilibrium the Sako-Wu-Prausnitz equation of state is applied. The model was tested on existing flocculation data for three systems of the type methane + i-octane + maltene + asphaltene with crude oils of different asphaltene contents. The amount of precipitant necessary to provoke flocculation was calculated in good agreement with the experimental data for all three systems up to a pressure of 15 MPa.
The synthesis of indazoles via 2,3‐dihydroindazoles

The preparation and oxidation of 2,3-dihydroindazoles to 1H, 2H or 3H-indazoles is described. A method for the synthesis of indazole 2-oxides has been found. Oxidation of 2-acetyl-2,3-dihydro-3,3-disubstituted indazoles 5a and 5c gave quinoid compounds 20a, 20b, 24a and 24b, which could be isomerized to 3H-indazoles upon removal of the acetyl group. A quinoid compound 21 was also obtained on treatment of 5a with tetracyanoethylene.
A general relation between the nucleation work and the size of the nucleus in multicomponent nucleation

We prove a general theorem that relates the variation of the work of formation of the critical nucleus with chemical potential and the size and composition of the critical nucleus. Applications are made to multicomponent nucleation and to both isothermal and nonisothermal phase transformations. We show that the excess number of molecules and the excess entropy of the critical nucleus are thus accessible to experimental determination with the help of data for the dependence of the nucleation rate on supersaturation. The results derived do not rely on classical nucleation approximations and thus apply down to the smallest nuclei of a few molecules only.
Freeze-Dried Preparations of Ketoprofen and Heptakis- (2, 6-O-Dimethyl) -β-Cyclodextrin

AbstractThe purpose of this study was to examine the inclusion formation in freeze-dried preparations of ketoprofen and heptakis-(2,6–0-dimethyl)-β-cyclodextrin. The products obtained were amorphous mixtures of the two components. X-ray diffractography, differential scanning calorimetry, 13C-CPMAS-NMR spectroscopy and thermofractography did not give any proof of an inclusion of ketoprofen in the cyclodextrin cavity.
Diagnostics of SiOx-Containing Layers Deposited on Powder Particles by Dielectric Barrier Discharge

We report on the analysis of the composition and internal structure of SiO x layers deposited on powder particles by using HMDSO as monomer, different oxygen admixtures in argon, and a dielectric barrier surface discharge under atmospheric pressure. Composition and structure of the deposited layers with special regard to silicon, carbon, and hydrocarbon bonding were studied by FTIR and XPS measurements and compared with previous investigations from the literature. For correlation of the layer composition and the plasma gas phase we used mass spectrometric analysis of the exhaust gas. The stoichiometric ratios of the deposited layers are remarkably influenced by the Ar/O 2 ratio and the discharge conditions.
Modelling of Hydrocarbon Solubility in Isomeric Ionic Liquids Using Mathematical Regressions

Linear Regression and Radial Basis Network models were explored for the prediction of heptane and toluene solubility in eleven ionic liquids at 313.15 K. The ILs were grouped in three groups of isomers. The models fitting performance was analyzed calculating statistical parameters (correlation coefficient and mean prediction error). For every model tested, the mean prediction error values in all three systems studied is less than 9.26 and 0.8% for linear regression and radial basis network models, respectively.
Investigation of the Suction Side Boundary Layer Development on Low Pressure Turbine Airfoils With and Without Separation Using a Preston Probe

Characterizing the transition process of airfoils can be very challenging and requires often extensive measurement methods. Frequently at low Reynolds numbers the suction side separation often occurs close to the trailing edge so that asserting reattachment of the flow to form a closed separation bubble from the profile pressure distributions becomes uncertain. In the current work the suction side transition process is investigated more precisely with a convenient method to determine the dynamic pressure close to the suction surface using a Preston probe (flattened Pitot tube). Therefore four low pressure turbine airfoils, which show different characteristics of the transition process in the static pressure distribution have been investigated at the High-Speed Cascade Wind Tunnel at the Universitat der Bundeswehr Munchen at constant Mach number and under a wide range of Reynolds numbers (40 000 to 400 000). It is shown that this method is appropriate to determine transition start and end as well as the separation and reattachment point of a separated flow as long as the probe height is small enough compared to the boundary layer thickness. The measurement results are compared to profile pressure distributions and hot-wire boundary layer profiles. Also the influence of periodic unsteady inflow conditions on the dynamic pressure near the wall is revealed in the time average. Limitations due to the probe geometry are discussed and a method to estimate the influence of the probe geometry on the measured dynamic pressure coefficient is suggested.Copyright © 2014 by ASME
Treatment of Methanogenic Landfill Leachate to Remove Ammonia Using a Rotating Biological Contactor (RBC) and a Sequencing Batch Reactor (SBR)

The authors investigated the use of a pilot scale rotating biological contactor (RBC) and a pilot scale sequencing batch reactor (SBR) to nitrify landfill leachate with a mean ammonia nitrogen concentration of 202 mg L−1 and mean BOD5 concentration of 50 mg L−1. The research was conducted under field conditions over a 14 month period. The research showed that, for this type of leachate, the RBC ammonia removal was superior to the SBR ammonia removal. The result appeared to be due to the low solids generation potential of this type of leachate, and the impacts of low temperature on the SBR system. Mixed liquor solids concentration appeared to be the critical factor in determining SBR ammonia removal. Full ammonia removal was achieved at RBC loading rates up to 4.5 g m−2 day−1, a hydraulic retention time of 0.3 days and a temperature of 18 °C. Full ammonia removal was achieved in the SBR unit at ammonia loading rates up to 400 g m−3 day−1 (0.6 g g MLSS−1 day−1), a hydraulic retention time of 0.7 days, and 2.
Magnetic Resonance Studies of Fluidization Regimes

Measurements of the voidage and velocity distributions in a gas-fluidized bed operating in the bubbling, turbulent, and core-annular fluidization regimes were acquired using magnetic resonance imaging (MR). The bed studied was contained in a column 50 mm in diameter and was fluidized with air. The particles were silica-alumina catalyst support loaded with water doped with gadolinium (diameter 63 μm, density of the water loaded particles 1530 kg m -3 ). Both time-averaged and ultrafast measurements are presented and provide the first noninvasive measurements of the velocities of particles and local voidage in a fluidized bed in each of the flow regimes. Measurements of the pressure fluctuations were also recorded as a function of the superficial velocity of the fluidizing gas to compare with the MR measurements. Ultrafast measurements of the voidage were used to examine the void structures present in the different flow regimes and to provide a means of studying the dynamics. A novel MR technique was used to measure the velocities of the particles in a diametral region of 15 mm x 15 mm square cross-section through the center of the bed every 7.7 ms. These measurements confirmed that the highest particle velocities in the bubbling fluidization regime occurred in the wakes of bubbles. The distribution of particle velocities in a bubbling bed is highly skewed; however, it approaches a Gaussian distribution and appears to scale with the superficial gas velocity in the turbulent fluidization regime. Finally, a simple model to infer the slip velocity in core-annular fluidization indicates that the particles in the center of the column group together in clusters with a diameter of between 4 and 8 particles.