Miracle-dz/UniFAR-FTUs huggingface dataset:
Failure analysis of Cu(In,Ga)Se2 photovoltaic modules: degradation mechanism of Cu(In,Ga)Se2 solar cells under harsh environmental conditions

High‐temperature‐induced and humidity‐induced degradation behaviors were investigated through the failure analysis of encapsulated Cu(In,Ga)Se2 (CIGS) modules and non‐encapsulated CIGS cells. After being exposed to high temperature (85 °C) for 1000 h, the efficiency loss of CIGS modules and the resistivities of the aluminum‐doped zinc oxide (AZO) layer, CIGS layer, and Mo layer were slightly increased. After damp heat (DH) testing (85 °C/85% RH), the efficiency of some modules decreased significantly accompanied by discoloration, and in these areas, the resistivity of the AZO layers increased markedly. The causes of degradation of CIGS cells after high temperature and DH tests were suggested through X‐ray photoelectron spectroscopy analysis. The high‐temperature‐induced degradation behaviors were revealed to be increases in series resistance of the CIGS cells, due to the adsorption of oxygen on the AZO, CIGS, and Mo layers. The degradation behavior after DH (85 °C/85% RH) exposure was caused by the adsorption of oxygen, as well as the generation of Zn(OH)2 due to water molecules. In particular, the humidity‐induced degradation behavior in discolored CIGS modules was ascribed to the generation of Zn(OH)2 and carboxylic acids in the AZO layer, due to a chemical reaction between the AZO, ethylene‐vinyl acetate copolymer, and water. Copyright © 2014 John Wiley & Sons, Ltd.
Mathematical modeling of a galvanostatic soil electroremediation process

A mathematical model for galvanostatic soil electroremediation of cadmium-spiked kaolinite was built considering: chemical and electrical properties from both phases, assumption of local equilibrium conditions, electroneutrality from phase interactions, a dynamic surface charge, and surface adsorbed concentrations defined by Boltzmann's equation. Model prediction trends agree with the expected phenomena to occur during an electroremediation process, as far as they show: a right electroosmotic fluid velocity with a suction effect at the anode position, a pH drop at the cathode position, soluble cadmium transport from anode to cathode, as well as cadmium accumulation before reaching the cathode, and a drop in electric potential gradient. Also, model strength allows the prediction of chemical species transient concentration; and provides an insight on species distribution through the spatial domain, while electroremediation takes place. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Morphological Control of Tapered and Multi‐Junctioned Carbon Tubular Structures

The myriad structural manifestations and their material properties have made carbon nanostructures very interesting not only for potential applications but also for understanding carbon at the atomic scale. Several different nano-sized structures of carbon have been investigated intensely. A few of these include single and multi-walled nanotubes, [1] helical nanotubes, [2] cones, [3] horns, [4] conical crystals, [5,6] micro-trees, [7] and nanopipettes. [8] The synthesis methods for carbon tubes with larger inner diameters are of interest for applications in micro-/nano-fluidics. Libera and Gogotsi [9] reported hydrothermal synthesis of graphite tubes with higher inner diameters ranging from 70±1300 nm using nickel as a catalyst. They also found that the tubes encapsulated ªhydrothermal fluidº and process gases during the growth with a fraction of the tubes also containing inner obstructions reminiscent of bamboo styling due to nickel catalyst. Bando and co-workers [10,11] synthesized gallium-filled straight nanotubes using thermal evaporation of gallium oxide mixed with carbon. Similar results were obtained with thermal evaporation of gallium nitride powder in the presence of acetylene. [12] These gallium-filled straight carbon tubes have been projected as nano-thermometers. Here, we describe a method for synthesis of new types of morphologies for carbon tubular structures based on varying inner diameter. It is shown that these new morphologies ± tapered tubes, nozzles, funnels, Y-junctions and multi-junctioned tubular structures ± can be tuned a priori through gas phase chemistry. These morphologies exhibit thin walls (10±30 nm) and very larger internal diameters (up to 2.5 lm) suitable for micro-/nano-fluidic, drug delivery, and nanoelec-tronic applications. A mechanism governing the controlled growth of these new morphologies of carbon nanostructures is presented. Typically, the growth of multi-walled carbon nanotubes is accomplished using transition metal catalysts such as nickel and iron. [13] During growth, the catalyst particle size and the growth interface do not change, thus maintaining a constant tube diameter. Controlling the morphology of the carbon nanostructures is of interest. Merkulov et al., [14] used nickel catalyst and relative concentrations of C 2 H 2 /NH 3 to synthesize a ªcylinder-on-coneº morphology. Again, the internal diameter of the structure is constant and determined by the nickel catalyst size. On the other hand, we hypothesized that the gallium meniscus with carbon in the absence or presence of oxygen or nitrogen would be different, similar to that of the dependence of contact angle on temperature. This variation of gallium meniscus shape with the growing ªtubeº will allow …
Chemical characterization of submicron Aerosol particles in Santiago de Chile

High time resolution chemical characterization of submicron particles was carried out in the South American city of Santiago de Chile using the Aerosol Chemical Speciation Monitor (ACSM). The instrumentation operated for 100 days from August 17 th to November 23 rd 2011 in an urban station located inside the University of Santiago de Chile (USACH) campus. In addition, a semi-continuous OC/EC analyzer was also run in parallel with the ACSM for some of this time. Meteorological conditions varied along the studied period due to the transition from winter to spring time. Atmospheric temperature inversions were responsible for hourly average sub-micron particulate matter levels of up to 80 μg/m 3 , especially during the night time. The average submicron particle mass concentration (± standard deviation) for the whole period was 29.8 ± 25 μg/m 3 . Aerosol particles were composed mainly of organics 59%, followed by nitrate, ammonium, sulfate, black carbon and chloride with contributions of 14, 12, 8, 3 and 3%, respectively. Using positive matrix factorization, the organic fraction was divided into four distinct types of organic aerosol representing fresh automobile exhaust, biomass burning, and two oxygenated organic aerosol factors with different oxidation states. The transition from winter to spring was clearly seen in the composition of OA. The emissions from primary sources, such as vehicle and biomass burning, decreased in the period leading to spring, whereas the amount of oxygenated organic aerosol increased over the same time. This study shows that high time resolution measurements of aerosol chemical composition can lead to better characterizations of the evolution and sources of pollutants in an urban atmosphere.
A Novel Modified Starch/Carboxymethyl Cellulose/Montmorillonite Bionanocomposite Film: Structural and Physical Properties

Abstract A novel glycerol-plasticized and citric acid (CA)-modified starch/carboxymethyl cellulose (CMC)/montmorillonite (MMT) bionanocomposite films were prepared from corn starch by casting, to study the effect of the 10% CA, 10% CMC and four different loadings of MMT on the properties of starch films. Atomic force microscopy surface analysis showed that starch/CMC/MMT films had the highest roughness. X-ray diffraction test showed that the clay nanolayers formed an intercalated structure in the bionanocomposites. However, completely exfoliated structure formed only in the pure starch/MMT nanocomposites (without CA and CMC). CA, CMC and MMT improved mechanical properties of starch films. MMT had the greatest effect on the mechanical properties. The MMT addition at content of 7% caused to increase in ultimate tensile strength by more than threefold in comparison to modified starch/CMC films. The water vapor permeability (WVP) decreased significantly (p < 0.05) by the addition of CA and CMC. When the MMT content of the starch films reached to 7%, the WVP decreased about 75% in comparison to the neat starch film. However, the hydrophilic character of bionanocomposites increased as the increasing of MMT content.
Oxygen scavengers and sensitizers for reduced oxygen inhibition in radical photopolymerization

Oxygen inhibition in the free-radical photopolymerization of (meth)acrylates is one of the most challenging problems in thin film application. Apart from the utilization of an inert gas atmosphere, additives reducing oxygen inhibition due to production of new propagating centers are used. In the present study, a more straightforward approach to reduce oxygen inhibition by photosensitized generation of singlet oxygen and subsequent scavenging of these species by selective singlet oxygen trappers was investigated. The potential of 1,2-dions conventionally used as type-II photoinitiators for visible light polymerization to function as singlet oxygen generators was verified in sensitized steady state photooxidation experiments in solution. A set of furan and anthracene derivatives were tested as oxygen scavengers and their corresponding relative reaction rates were determined. The ability of these sensitizer/scavenger systems to reduce oxygen inhibition in practical applications was studied in photo-DSC-experiments. In thin film polymerization (investigated by ATR-FTIR), the formation of insufficiently cured surfaces could be prevented by the usage of singlet oxygen trappers. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6916–6927, 2008
Time-Lapse Thiol-Acrylate Polymerization Using a pH Clock Reaction

A time-lapse polymerization exhibits a programable timebetween the mixing of the reagents and the onset of poly-merization. In fact, a free-radical polymerization systemcontaining an inhibitor can be thought of this way. Anotherapproach was invented by Norling that consisted of aperoxide or persulfate initiating system using iron or copperwith a special chelating agent and an organic reducingagent.
Polymer Brushes that Resist Adsorption of Model Proteins: Design Parameters

The adsorption of model proteins onto brush-coated surfaces can occur via two modes. Primary adsorption at the surface, where short range attraction is dominant, is important for small proteins and may be repressed by increasing the grafting density. Secondary adsorption, due to van der Waals attraction, occurs at the outer edge of the brush. Large rodlike proteins are likely to adsorb in this fashion. This mode may be repressed by increasing the brush thickness. The thermodynamics and kinetics of adsorption of model proteins are considered within a simple analytical theory distinguishing between the different adsorption mechanisms of small and big proteins.
Die Acidität der Sulfane und die Zusammensetzung wässeriger Polysulfidlösungen

The pure salts Na2S2, K2S2, K2S3, Na2S4, K2S4 and K2S5 have been prepared. Titration curves of these polysulfides in aqueous solution have been obtained with a special streaming apparatus, with which the mixing of the polysulfide solution with HCl and the pH determination of the fresh mixture is accomplished within 10−2 seconds. This time is too short for decomposition of the protonated polysulfide anions into sulfur and monosulfide or H2S respectively to occur. With K2S5 the buffer regions S52− ⇄ HS5− ⇄ H2S5 were obtained readily, furnishing the pK's of H2S5. The solutions of the lower polysulfides, however, do not contain simply the anions present in the lattice of the solid salt. As soon as the solid salts are dissolved disproportionation reactions take place giving rise to mixtures. From the protonation curves of these mixtures—taken with the streaming device mentioned—their composition can be deduced, and it was found that all solutions contain the ions OH−, SH−, S42− and S52−. The ions S22− and S32− were never detected. The equilibrium between mono-, tetra- and pentasulfide has been elucidated and the pK's of H2S4 have been obtained. The results have been checked with photometric measurements on the polysulfide solutions.
Experimental study on copper cathode erosion rate and rotational velocity of magnetically driven arcs in a well-type cathode non-transferred plasma torch operating in air

The cathode erosion rate, arc root velocity and output power of a well-type cathode (WTC), non-transferred plasma torch operating in air are studied experimentally in this paper. An external solenoid to generate a magnetically driven arc and a circular swirler to produce a vortex flow structure are equipped in the studied torch system, which is designed to reduce the erosion rate at the cathode. A least square technique is applied to correlate the system parameters, i.e. current, axial magnetic field and mass flow rate, with the cathode erosion rate, arc root velocity and system power output. In the studied WTC torch system, the cathode erosion has a major thermal erosion component and a minor component due to the ion-bombardment effect. The cathode erosion increases with the increase of current due to the enhancement in both Joule heating and ion bombardment. The axial magnetic field can significantly reduce the cathode erosion by reducing the thermal loading of cathode materials at the arc root and improving the heat transfer to gas near the cathode. But, the rise in the mass flow rate leads to the deterioration of erosion, since the ion-bombardment effect prevails over the convective cooling at the cathode. The most dominant system parameter to influence the arc root velocity is the axial magnetic field, which is mainly contributed to the magnetic force driving the arc. The growth in current has a negative impact on increasing the arc root velocity, because the friction force acting at the spot due to a severe molten condition becomes the dominant component counteracting the magnetic force. The mass flow rate also suppresses the arc root velocity, as a result of which the arc root moves in the direction against that of the swirled working gas. All system parameters such as current, magnetic field and gas flow rate increase with the increase in the torch output power. The experimental evidences suggest that the axial magnetic field is the most important parameter to operate the straight-polarity WTC plasma torch at high output power with a limited cathode erosion rate. This emphasizes the importance of an external magnetic field on a WTC torch system for reducing the erosion at the cathode.
SEPARATION OF THREE TRITERPENE ACIDS IN LEAVES OF DIOSPYROS KAKI BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY USING HYDROXYPROPYL-β-CYCLODEXTRIN AS MOBILE PHASE MODIFIER

An improved high-performance liquid chromatography method for the separation and determination of rotungenic acid and two isomeric triterpene acids (oleanolic acid and ursolic acid) was developed. Results proved that these triterpene acids can be separated with high resolution by adding hydroxypropyl-β-cyclodextrin (HP-β-CD) into the mobile phase; the resolution of the triterpene acids increased and their retention time in the column decreased with HP-β-CD concentrations increasing due to the formation of inclusion complexes between triterpene acids and HP-β-CD. The formation of 1:1 inclusion complexes was assumed and apparent formation constants of triterpene acids with HP-β-CD were determined experimentally at 20°C and 35°C. At last, the method was used to determine rotungenic acid, oleanolic acid, and ursolic acid in the leaves of Diospyros kaki and proved to be sensitive, rapid, accurate, and suitable.
Synthesis of reduced graphene oxide by an ionothermal method and electrochemical performance

An easy ionothermal method is proposed to deoxygenate graphene oxide (GO) for preparation of graphene by using a choline chloride (ChCl)/urea mixture-based ionic liquid. In the synthesis process, the urea portion in the ionic liquid breaks up to release NH3 at around 100 °C. This reacts with the oxygen functional groups of the GO sheets, leading to the formation of graphene. The ionothermal method is an environmentally-friendly and attractive strategy for reducing GO because both ChCl and urea are naturally biocompatible compounds. X-Ray photoelectron spectroscopy indicates that nitrogen atoms can be doped into the graphene skeleton accompanied by the reduction of GO. As an electrode for an electrochemical double layer capacitor in aqueous KOH, the ionothermally reduced GO exhibits a gravimetric capacitance of 155 F g−1 at a current density of 0.2 A g−1 and good cycling performance, which is comparable to the hydrazine reduced GO. We expect that the ionothermal method will have implications for the use of ionic liquids in the large-scale synthesis of graphene-based materials.
The Crystal Structure of Lepidocrocite

The unit of structure, space group symmetry and detailed atomic arrangement of lepidocrocite are determined from x‐ray data, and the existence and location of hydrogen bonds in the structure are established from considerations of interatomic distances. The orthorhombic lattice is end centered on (100), and has the axes a0 = 3.87A, b0 12.51A, and c0 = 3.06A. The space group is Vh17—Amam. The parameters are determined as uFe = —0.332, uO = +0.282, and uOH = +0.075. The structure is described as consisting of iron‐centered oxygen octahedra joined by the sharing of edges into two‐dimensionally infinite layers, with the successive layers held together by hydrogen bonds. The relationship between the diaspore‐goethite structure and the bohmite‐lepidocrocite structure is discussed from the standpoint of the coordination theory, and found to depend on two alternative ways of satisfying the electrostatic valence rule.
CFD Simulation of Liquid Film Flow on Inclined Plates

A two-phase flow CFD model using the volume of fluid (VOF) method is presented for predicting the hydrodynamics of falling film flow on inclined plates, corresponding to the surface texture of structured packing. Using the proposed CFD model the influence of the solid surface microstructure, liquid properties and gas flow rate on the flow behavior was investigated. From the simulated results it was shown that under the condition of no gas flow the liquid flow patterns are dependent on the microstructure of the plates, and proper microstructuring of the solid surface will improve the formation of a continuous liquid film. It was also found that liquid properties, especially surface tension, play an important role in determining the thin-film pattern. However, there are very different liquid film patterns under the action of gas flow. Thinner liquid films break easily, but thicker liquid films can remain continuous even at higher gas flow rates, which demonstrates that all factors affecting the liquid film thickness will affect the liquid film patterns under conditions of counter-current two-phase flow.
Zeolite-like Metal−Organic Framework Based on a Flexible 2-(1H-benzimidazol-2-ylthio)acetic Ligand: Synthesis, Structures, and Properties

A zeolite-like metal−organic framework (ZMOF) has been successfully constructed by using a flexible ligand, 2-(1H-benzimidazol-2-ylthio)acetic acid (H2L). Under different conditions, four new compounds, [Zn2(HL)4]·(DMF)2·(H2O)2 (1), [Zn2(HL)4]n (2), [Cu(HL)2]n (3), and [Co(L)]n (4), have been synthesized and characterized with this ligand. Complex 1 exhibits a binuclear macrocyclic structure, while 2 is a two-dimensional (2D) (4,4) amphiphilic layer further forming a 3D network via van der Waals interactions between the hydrophobic sides and C−H···O interactions between hydrophilic sides. In 3, the 2D (4,4) layers are linked by C−H···C interaction to form a three-dimensional framework, and complex 4 shows a zeolite sodalite (SOD) topology, which represents the first ZMOF from flexible ligands. The fluorescent emissions of 1 and 2, and the magnetic properties of 4 have also been studied.
Temperature dependency of granule characteristics and kinetic behavior in UASB reactors

When an inhibitory substrate, phenol, was treated under mesophilic conditions (25, 30, 35, and 40 °C), the upflow anaerobic sludge bed (UASB) reactors at 30 °C resulted in the greatest amount of biomass and the largest granule size, while the UASB reactors at 25 °C resulted in the smallest granule size and the greatest amount of wash-out of sludge. The granule size tended to be negatively correlated with the amount of wash-out of sludge. With an increase in temperature, the kinetic constant k for anaerobic phenol degradation increased and the half saturation constant (Ks) decreased. The mass fraction of methanogens (f) increased with increasing operational temperature in the UASB reactors and the activation energy (Ea) for acetate methanogenesis was larger than that for phenol acidogenesis in the batch reactors, indicating that the operational temperature imposes a more influential effect on methanogens than on acidogens. From the results of the activity of acidogens and methanogens (expressed in specific COD utilization rate), the rate-limiting step is phenol acidogenesis. Copyright © 2004 Society of Chemical Industry
Preparation and Slow-Release Properties of Clay-Based Phosphatic Fertilizers

With potassium dihydrogen phosphate acting as raw material, using grinding and adsorption methods to prepare diffrent kinds of clay-based phosphatic fertilizers. And later, using sodium alginate to coat the fertilizers. Choosing soil leaching method to evaluate their slow-release properties. The results indicate that carrier properties have great influences on slow-release properties, the effect of different carriers are as follows: bentonite > kaolin> common earth. The coordinated role of bentonite and hydrotalcite to the slow-release properties is better than the single role of bentonite. The coating of sodium alginate can improve the slow-release properties of clay-based fertilizers.
Lessons From Cyclosporine A: Structural Determinants of Conformation-Switching and Passive Membrane Penetration

The structural complexity of ‘beyond-rule-of-5’ compounds, such as peptide macrocycles, may facilitate access to additional biological target space beyond the enzymatic active site. Naturally occurring cyclic peptides, in particular, exhibit a wide variety of unusual and potent biological activities. Cyclosporine A (CsA), the canonical ‘rule-breaking’ molecule, is heavily N-methylated, and it is widely held that this contributes to its unexpectedly high oral bioavailability. This has been a major motivator of the use of N-methylation to enhance the ability of cyclic peptides to cross lipid bilayers. The evidentiary basis of this, stems largely from structural studies which predict that all the backbone amide bonds of CsA that are not engaged in transannular hydrogen bonds in the suspected ‘cell-permeable conformation,’ are otherwise N-methylated. However, to our knowledge, no direct, systematic analysis of the effect of N-methylation on cell permeability and target engagement of CsA has been reported. In order to gain a deeper understanding of this structurally-significant molecule, we
NTChem: A high‐performance software package for quantum molecular simulation

In this Software News, the authors introduce NTChem, a new comprehensive software package developed in Japan, for ab initio quantum chemistry calculations. It includes various high-performance computational methods and functions for quantum molecular simulations. Furthermore, it is designed for high-performance calculations on a computer with numerous compute nodes. Therefore, it makes optimum use of the K computer's processing power. This Software News specifically examines the parallel performance of NTChem on the K computer. © 2014 Wiley Periodicals, Inc.