Miracle-dz/UniFAR-FTUs huggingface dataset:
InGaP/GaAs/Ge triple‐junction solar cells with ZnO nanowires

ZnO nanowire (NW) grown on triple‐junction (TJ) solar cells via the hydrothermal growth method to enhance efficiency is investigated. In this paper, experimental results indicate that TJ solar cells with ZnO NW as an antireflection (AR) coating have the lowest reflectance in the short wavelength spectrum, as compared with those of bare TJ solar cells (without AR coating) and solar cells with SiNx and TiO2/Al2O3 AR coatings. ZnO NW has the lowest light reflection among all experimental samples, especially in the range of ultraviolet to green light (300–500 nm). It was found that ZnO NW could enhance the conversion efficiency by 6.92%, as compared with the conventional TJ solar cell. In contrast, SiNx and TiO2/Al2O3 AR coatings could only enhance the conversion efficiency by 3.72% and 6.46% increase, respectively. The encapsulated results also suggested that the cell with ZnO NW coating could provide the best solar cell performances. Furthermore, all samples are measured at tilt angles of 0°–90° and results show that the solar cells with ZnO NW have the highest efficiency at all tilt angles. Furthermore, a small NW diameter increases light absorption. Copyright © 2012 John Wiley & Sons, Ltd.
Changes in the Humic Acid–Metal Complexation Characteristics Depending on Humification Degree / Humīnskābju – Metālu Kompleksveidošanās Rakstura Izmaiņas Atkarībā No Humifikācijas Pakāpes

The aim of this study is to determine the Cu(II) complexing capacity and stability constants of Cu(II) complexes of humic acids isolated from two well-characterized raised bog peat profiles in respect to the basic properties and humification characteristics of the studied peats and their humic acids. The complex stability constants significantly change within the studied bog profiles and are well correlated with the age and decomposition degree of the peat layer from which the humic acids have been isolated. Among factors that influence this complexation process, molecular mass and ability to form micellar structures (supramolecules) of humic substances are of key importance. KOPSAVILKUMS Darbā pētītas humusvielas, kas izdalītas no diviem augstā tipa purvu kūdras profiliem, ņemot vērā pētāmo kūdru un izdalīto humusvielu īpašības un humifikācijas pamatiezīmes. Kompleksveidošanās konstantes būtiski mainās pētīto purvu profilu robežās, kā arī novērota šo konstanšu vērtību korelācija ar kūdras slāņa vecumu un sadalīšanās pakāpi. Kūdras sadalīšanās procesi ir būtisks faktors, kas ietekmē humusvielu kompleksveidošanās spējas. Neviena no apskatītajām humīnskābju pamatīpašībām, piemēram, karboksilgrupu koncentrācija, kopējais skābums atsevišķi nevar pilnībā izskaidrot HV kompleksveidošanās spējas.
GaN nanowires for piezoelectric generators

We demonstrate the high potential of GaN nanowires (NWs) to convert mechanical energy into electric energy. Using an atomic force microscope equipped with a Resiscope module, an average output voltage of –74 mV and a maximum of –443 mV ± 2% per NW were measured. This latter value is the highest reported so far for GaN NWs. By considering these output signals, we have estimated an average and a maximum power density generated by one layer of GaN NWs of the order of 5.9 mW/cm2 and 130 mW/cm2, respectively. These results offer promising prospects for the use of GaN NWs for high‐efficiency ultracompact piezogenerators. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Self-assembled poly(2-ethyl-2-oxazoline) fibers in aqueous solutions

Poly(2-ethyl-2-oxazoline) (PEOX) formed self-assembled fibers in aqueous solutions above the cloud point temperature (Tc) through a slow crystallization process. The fiber formation above Tc happened both in pure water and in the presence of salting-in (SCN−) and salting-out (CH3COO−) ions. The crystal structure and the melting temperature of the PEOX fibers were determined.
INTERNAL ENVIRONMENT OF SOLID ROCKET NOZZLES.

Abstract : A study was conducted of solid propellant rocket motor nozzle environment to implement nozzle design methods. Cold flow studies with models plus hot firing tests for particle impingement and particle cloud radiation are to be used to characterize heat flux rates throughout the nozzle. This report describes the hardware buildup and schedule of heat flux tests on a molybdenum nozzle with hydrogen, oxygen, water, and varying amounts of alumina. Cold flow technique development has shown interesting particle impingement effects as a function of modeling system design and nozzle shape. The implied full scale particle impingement rates are listed for the first two cases studied. A complete report is given on a program studying radiation of a hydrogen-oxygen-alumina plume from a one-inch diameter throatless engine. High emissivity values are indicated for all but the smallest engines. (Author)
Surface-Initiated Polymerizations in Aqueous Media: Effect of Initiator Density

We report the first systematic study of initiator density on surface-initiated polymerizations. We used mixed monolayers comprising of undecanethiol and ω-mercaptoundecyl bromoisobutyrate (1) to initiate the controlled radical polymerization of methyl methacrylate (MMA) and glycidyl methacrylate (GMA) from gold. We found that SAMs composed of 10% and 50% of initiator 1 grow PMMA brushes to approximately 1/10 and 1/2 the thickness of polymer brushes grafted from SAMs comprising 100% 1. We did not find a clear maximum initiator density, beyond which no further increase in polymer brush thickness is observed. We show that the initiator density at the start of the polymerization determines the ultimate “footprint” and hence density of polymer molecules in polymer brushes.
Detection and Identification of Oestrogen‐Active Substances in Plastic Food Packaging Migrates

Migrates from plastic food packaging were tested for oestrogen activity by yeast oestrogen screen and subsequently analysed by gas chromatography—mass spectrometry and high‐performance liquid chromatography—mass spectrometry to identify oestrogen‐active chemicals. Plastic samples were migrated according to EC 10/2011 with worst case scenarios being used. Food simulants consisted of either 10–95% ethanol or ultrapure water. Migrates were concentrated afterwards by solid phase extraction. Food contact material tested included polyethylene terephthalate, polypropylene, polyethylene, polystyrene and composite films. Oestrogenic activity ranging from 0.7 to 59 ng/l 17ß‐estradiol equivalents was detected in seven out of 42 samples tested. The highest activity was found in a composite film sample. All 11 polyethylene terephthalate samples tested negative for oestrogen activity. A number of chemicals with known or supposed oestrogen activity were identified in migrates of oestrogen‐active samples. These include butylated hydroxytoluene, 1,3‐diphenylpropane, 1,2‐diphenylcyclobutane and dibutyl phthalate. Copyright © 2013 John Wiley & Sons, Ltd.
Biodegradable copolyester/starch blends - preparation, mechanical properties, wettability, biodegradation course

A set of blends of an aromatic-aliphatic copolyester containing 35 mol. % of aromatic ester units and plasticized wheat starch has been prepared. The copolyester used in this process was synthesized by polycondensation of the product of solvolysis of polyethyleneterephthalate (PET) from disposed beverage bottles by an aqueous solution of lactic acid. The blends copolyester/starch were characterized by their tensile strength and wetting behavior. Biodegradability of the blends was tested by using of mixed culture of microorganisms of digested sludge from wastewater treatment plant under anaerobic thermophilic conditions (55 °C).
VARIATIONS OF FLAVOR SUBSTANCES IN DISTILLATION PROCESS OF CHINESE LUZHOU-FLAVOR LIQUOR

ABSTRACT To investigate the variations of flavor substances in distillation process of Chinese Luzhou-flavor liquor, systematic experiments were carried out in an industrial-scale experimental distiller. Distillate samples were collected continuously throughout the whole distillation process and analyzed by gas chromatography and sensory evaluation. The results show that the compositions and variations of flavor substances mainly depend on their physical and chemical properties. The flavor substances with low boiling point, such as ethanol, acetaldehyde, ethyl format and ethyl acetate, are vaporized quickly and therefore have high contents in the distillate obtained in the early stage of distillation. The flavor substances with high boiling points enter into distillate mainly by extraction and, hence, their variations depend on the dissolving properties. The alcohol-soluble substances, such as ethyl hexanoate, ethyl butanoic and so on, are distilled out mainly in the early stage of distillation, and their extraction rates decrease as the distillation process proceeds, while the water-soluble substances, such as organic acids, ethyl lactate and so on, are mainly present in the latter-stage distillate and the extraction rates increase as the process proceeds. Variations of methanol and furfural were found irregular and the reasons for this irregularity were analyzed. Sensory quality of distillate declines as the distillation process proceeds. PRACTICAL APPLICATIONS Chinese liquor has been a traditional art continuing for thousands of years, but the distillation operation almost holds its way of ancient time and few studies about it have been conducted, so that the understanding of distillation process is largely limited to intuition. Variations of flavor substances during distillation process will certainly contribute to the understanding of distillation mechanism and the optimization of distillation operation. The remarkable differences of distillate qualities found in different distillation stages provide an experimental base for collecting liquors with different distillate qualities. The findings that the high quality distillate is produced in early distillation stage indicate the necessity to overcome the vapor-overflow phenomenon, which occurs usually in the early stage of distillation and causes a lot of loss of high quality liquor. Theoretically, this work will provide the experimental base and testifying data for the modeling of multicomponents mass transfer in liquor distillation process through a packed bed.
Zur Abhängigkeit der Oberflächenspannung von der Bildungs‐ und Alterungsgeschwindigkeit der Oberfläche

Die dynamische Oberflächenspannung von destilliertem Wasser wurde nach der Methode der Flüssigkeitsglocken bestimmt. Die gefundene Abhängigkeit der Oberflächenspannung von der Bogenlänge der Meridiankurve kann aus dem Ordnungszustand der Oberflächenbereiche der stationär abfließenden Wasserhaut erklärt und durch einen quantitativen Ansatz für die Oberflächenenergie befriedigend wiedergegeben werden. Die Relaxationszeit des Alterungsvorganges der Oberfläche (Abklingen der dynamischen Oberflächenspannung auf den statischen Gleichgewichtswert) wird in der Größenordnung von 10−3 sec gefunden.
Thermal modeling of an on‐board nickel‐metal hydride pack in a power‐split hybrid configuration using a cell‐based resistance–capacitance, electro‐thermal model

Presented study discusses the development of a finite differencing (FD) thermal model for a power‐split hybrid configuration employing a nickel‐metal hydride battery pack. A resistance–capacitance electro‐thermal model is used to couple the experimental boundary conditions (current, voltage, state of charge, and temperature) with the modeled battery resistance to capture its electro‐chemical behavior and the cell exothermic reactions. Battery current, voltage, and temperature (discrete and full field) for a vehicle with a power‐split hybrid configuration were collected under different standard (Federal Highway Driving Schedule and Federal Urban Dynamometer Driving Schedule (FUDS)) and artificially generated driving cycles. This manuscript analyzes the battery current and voltage in relation to vehicle speed and shows how the proposed FD model predicts the spatial and temporal temperature profiles of the power train in good agreement with the vehicle data as reported by the on‐board diagnostics module. Copyright © 2011 John Wiley & Sons, Ltd.
Knowledge Mining in Supervised and Unsupervised Assessment Data of Students’ Performance

There are several statistical tools being used for students’ performance analysis for information extraction and knowledge discovery. This paper presents data mining approach applied to discover students’ performance patterns in supervised and unsupervised assessment instruments of a course in an engineering degree program. The interesting patterns emerging from this analysis promise to offer some helpful and constructive suggestions to educational administrators and decision makers in the sector of higher education for the improvement and revision of assessment methodologies, restructuring the curriculum, and trimming down the mismatch between the two modes of assessments.
The improvement of InAs/GaAs quantum dot properties capped by Graphene

InAs self-assembled quantum dots (QDs) were grown by molecular beam epitaxy on (001) GaAs substrate. Uncapped and capped QDs with GaAs and graphene layers were studied using atomic force microscopy and Raman spectroscopy. Graphene multi-layer was grown by chemical vapor deposition and transferred on InAs/GaAs QDs. It is well known that the presence of a cap layer modifies the size, shape, and density of the QDs. According to the atomic force microscopy study, in contrast to the GaAs capped sample, which induce a dramatic decrease of the density and height of dots, graphene cap layer sample presents a slight influence on the surface morphology and the density of the islands compared with the uncapped one. The difference shown in the Raman spectra of the samples is due to change of strain and alloy disorder effects on the QDs. Residuals strain and the relaxation coefficients have been investigated. All results confirm the best crystalline quality of the graphene cap layer dots sample relative to the GaAs capped one. So graphene can be used to replace GaAs in capping InAs/GaAs dots. To our knowledge, such study has not been carried out until now. Copyright © 2013 John Wiley & Sons, Ltd.
Silicon nanowires – a versatile technology platform

Silicon nanowires offer unique properties like inherent small diameters, quasi-one-dimensional current transport and the flexibility to combine materials that cannot be combined in bulk or thin film structures. Based on these properties electron devices, sensors as well as solar cells and lithium batteries can be envisioned that significantly outperform their thin film or bulk counterparts. The possibility to form silicon nanowires in a top-down process using bulk silicon or silicon-on-insulator substrates, gives this technology the potential for a seamless integration into integrated electronic systems. This Review gives an overview of important device applications of silicon nanowires. Starting with nanowire fabrication, the different device concepts will be introduced and their most important features are reported.
Effects of rainfall intensity and antecedent moisture on the steady-state infiltration rate in a semi-arid region

The infiltration and runoff responses of degraded and non-degraded semi-arid land surfaces were investigated by rainfall simulation in the Lowveld of Swaziland. The hydrological response of the soil was controlled by changes in the properties of the soil surface, the nature of which was dependent upon rainfall intensity and antecedent moisture, as well as upon soil type and condition. Rather than there being one final steady-state infiltration rate for a given soil type and condition (i.e. a constant of soil response), the final rates achieved were variable for each soil type and condition, and depended upon rainfall intensity and antecedent moisture. The implications of this for soil use and management in terms of infiltration measurement and runoff assessment are considered.
Mycotoxins in indoor environments. Determination using mass spectrometry.

Dampness in indoor environments may cause various health problems. The specific causative agent(s) are unknown but may originate from degradation processes in damp materials, microbial growth, or a combination of these phenomena. The health impact of dampness in buildings is a politically, legally, and economically important question. Scientists at the U.S. EPA and Lawrence Berkeley National Laboratory have estimated that the symptoms of 4.6 of the total of 21.8 million asthmatics in the USA are caused by indoor dampness and mold to an annual cost of 3.5 billion dollars. Mycotoxins are secondary metabolites produced by molds which may be e. g. cytotoxic (e. g. macrocyclic trichothecenes produced by Stachybotrys chartarum), genotoxic (e. g. sterigmatocystin and aflatoxins produced mainly by Aspergillus spp. including A. versicolor and A. flavus), or immunosuppressive and neurotoxic (e. g. gliotoxin produced by Penicillium spp. and Aspergillus spp. e. g. A. fumigatus). Airborne mycotoxins have been demonstrated in water-damaged buildings using both ELISA and mass spectrometry. However, whether mycotoxins at the concentrations found in mold-damaged environments represent a health risk upon inhalation is not known. The mechanisms for mycotoxin uptake, metabolism, and interaction e. g. with other fungal constituents such as proteins and (1→3)-β-D-glucan (a fungal cell membrane constituent) are poorly understood. In this project analytical methods for the detection and determination of selected mycotoxins using GC-MS and HPLC-MS were developed. The methods were applied to 167 mold-contaminated building material samples, of which 67 % were mycotoxin positive. Thus, many molds not only posess the genetic capacity to produce mycotoxins but do it regularly in water damaged indoor environments. In addition, we demonstrated mycotoxins in dust settled in the breathing zone in indoor environments where severe mold-contamination was identified on building materials. We thereby confirm that mycotoxins on such materials can become airborne and thus inhalable. This project is an example of fruitful national and international inter-disciplinary collaboration between the building industry, companies specialized in remediation measures, and universities. (Less)
VIDEO SELF-MODELING AS EVIDENCE-BASED INTERVENTION

Video self-modeling (VSM) is an evidence-based intervention that has been shown to be effective in addressing a variety of skills in individuals with Autism Spectrum Disorder (ASD). This article reviews the empirical evidence supporting the use of video self-modeling among a wide range of skills and abilities. Future research and suggestions are
Diarylated Ethanones from Mo(CO)6-Mediated and Microwave-Assisted Palladium-Catalysed Carbonylative Negishi Cross-Couplings

Two protocols for palladium-catalysed carbonylative Negishi cross-couplings were developed for aryl iodides and aryl bromides. The two main breakthroughs were that molybdenum hexacarbonyl [Mo(CO)(6)] could be used as a solid in situ source of CO, and that controlled microwave irraditaion could be used for heating. Consequently, the reactions were safe (in contrast to when CO gas was used) and fast (in comparison to when conventional heating was used). The carbonylative cross-coupling reactions were carried out using commercially available benzylzinc bromide in closed vials (90-120 degrees C for 0.5-1 h) to give a set of diarylated ethanones, a common pharmacophore found in several pharmaceuticals, in moderate to high isolated yields (47-84%). The mild three-component carbonylation protocol presented here is operationally simple, safe, and rapid, and the formation of the carbonylative Negishi cross-coupling product is favoured over the product of Negishi cross-coupling.
Highly electrically conductive indium–tin–oxide thin films epitaxially grown on yttria-stabilized zirconia (100) by pulsed-laser deposition

Highly electrically conductive indium–tin–oxide thin films were epitaxially grown on an extremely flat (100) surface of yttria-stabilized zirconia single-crystal substrates at a substrate temperature of 600 °C by a pulsed-laser deposition technique. A resistivity down to 7.7×10−5 Ω cm was reproducibly obtained, maintaining optical transmission exceeding 85% at wavelengths from 340 to 780 nm. The carrier densities of the films were enhanced up to 1.9×1021 cm−3, while the Hall mobility showed a slight, almost linear, decrease from 55 to 40 cm2 V−1 s−1 with increasing SnO2 concentration. The low resistivity is most likely the result of the good crystal quality of the films.
Twinning and pseudosymmetry under high pressure

Abstract We review the available information on crystal twinning at high pressures and analyze the effect of hydrostatic pressure on the pseudosymmetry of selected compounds. Twinning by merohedry, type I and II, as well as pseuomerohedral twinning at high pressures has been described. For twinning by merohedry type I (inversion twinning) a reliable characterization of the twin domains and volume fractions is difficult and largely depends on the experimental conditions, i.e. the number of measured Friedel pairs and the chosen wavelength. For twinning by merohedry, type II, and for twinning by pseuodmerohedry twin volume fractions could be reliably determined for several cases. In none of these a significant influence of hydrostatic pressure on the volume fractions of the individuals was observed. Pressure-induced twinning has been observed for compounds which undergo first-order phase transitions. The twinning operation in the described cases is related to the loss of rotational symmetry elements of the higher symmetrical polymorph although the high and low pressure phases are not in group-subgroup relationship. The analysis of pseudosymmetry of several compounds as a function of pressure suggests that this parameter can be used to predict the (in)stability of compounds. In particular, a decrease in pseudosymmetry seems to be strongly correlated with the occurrence of first-order phase transitions in which the crystal breaks or amorphizes. The effect of hydrostatic and chemical pressure on the pseudosymmetry of the crystal structures can lead to different or even opposite trends, suggesting that the increase or decrease of pseudosymmetry cannot be understood as a pure volume effect.
Normal Accidents: A Statistical Interpretation

Perrow (1984) introduced the concept of "normal accidents" arising from his sociological study of hazardous incidents in supposedly high-integrity systems. Normal accidents turn out to have a natural interpretation within the statistical theory of process capability. Such faults within systems are often overlooked because of their very complexity. Conventional design-analysis methods offer only limited protection This paper uses ideas from the Shewhart-Deming theory of process management to propose statistical tools that can safeguard complex systems against normal accidents.
Production of 2-hydroxyacetylfuran from lignocellulosics treated with ionic liquid–water mixtures

Japanese cedar (Cryptomeria japonica) was treated with 12 ionic liquid (IL)–water mixtures at 120 °C for 1 h. Production of 5-hydroxymethylfurfural, furfural and 2-hydroxyacetylfuran (2-HAF) was observed by HPLC and GC-MS. This is the first report to identify 2-HAF from lignocellulosics using ILs. The optimal IL–water mixture was found to be a 90% pyridinium chloride and 10% water w/w solution, although any IL–water mixture that contained pyridinium or imidazolium salts produced all three compounds in varying yields.