Miracle-dz/UniFAR-FTUs huggingface dataset:
Cooperative enhancement of two- and three-photon absorption in dendrimers and their underlying coherent domain structure

At present a special attention is concentrated on increasing of the efficiency of multi-photon absorption of organic systems because of new emerging applications based on this effect. In our experiments we use strong two-photon absorbing chromophore, 4,4’-bis(diphenylamino)stilbene (BDPAS), to design new dendrimer molecules, in such a way that the branching center allows for pi-electronic conjugation between branches. Here we present, for the first time, unambiguous spectroscopic evidence of strong cooperative enhancement of two-photon and three-photon absorption in a series of these dendritic macromolecules. Maximum two-photon cross section increases in proportion to N2, where N = 2, 4, 6 is the number of constituent identical chromophore units in the parent BDPAS and lowest, G-0 dendrimer generation. Almost the same scaling law is observed for three-photon absorption. For higher generations, G-1 and G-2, comprising N = 14 and 30 chromophores, respectively, the cooperativity in multiphoton response starts to saturate. We show that three-photon absorption provides important complementary information, which we use for evaluation of the size of domains where chromophores are coherently coupled.
Removal of Zinc(II) and Manganese(II) from Crude Phosphoric Media by Bis(2,4,4‐Trimethylpentyl) Phosphinic Acid (Cyanex‐272)

Purification of commercial phosphoric acid produced by the wet process from toxic heavy metals such as zinc and manganese is considered to be a very important environmental and economical process. The commercial bis(2,4,4‐trimethylpentyl)‐ phosphinic acid (Cyanex‐272) is proposed as an extractant for the efficient removal of Zn(II) and Mn(II) from crude phosphoric acid samples of concentrations of 25% and 45%. Various parameters affecting the extraction rate of Zn(II) and Mn(II) were investigated. The results were assessed to obtain the optimum conditions for the fast and efficient removal of both cations from crude phosphoric acid using Cyanex‐272 as an extractant in various diluents. The selectivity sequence of different diluents for Zn(II) and Mn(II) extraction were: kerosene > n‐hexane > cyclohexane > toluene > benzene > chloroform. The stripping of the investigated metal ions is efficiently performed with ammonium thiocyanate which has been selected as a suitable stripping agent.
Global or Local? A Choice for NIR Calibrations in Analyses of Forage Quality

This paper investigates the effect of spectral data pre-treatment by using scatter correction techniques, detrending and derivatives on the standard error of NIR predictive models. It is shown that no particular spectral pre-treatment or no single derivative works best for the three constituents (protein, cellulose, organic matter digestibility) of the three forage databases which we investigated (grass-hay, tropical forages, maize whole plants). The best analytical results are obtained with SNVD, MSC or WMSC treatments. The best results are obtained with a first or second derivative with a segment and a gap of five data points. Local Regression was investigated for the prediction of forage quality. The standard errors of prediction were compared with those obtained with the best global calibration. Trial and error is the only way to fix the number of samples in the subset and the number of terms to retain in the model. Compared to the results for the traditional universal calibration method, the gain in SEP for protein, cellulose and digestibility in grass-hay, tropical forages or maize ranges between 5 and 11%.
Kinetics of hydrogen reduction of nickel sulfide

The hydrogen reduction of powdered nickel sulfide (Ni3S2) at atmospheric pressure in the temperature range 475 to 630 °C has been experimentally investigated. The true intrinsic kinetics of this reaction were obtained, under conditions such that the topochemical shrinking core model in the chemical control regime could be applied. In the temperature range 475 to 530 °C, the rate constant could be expressed by the following equation: Above 530°C, whisker formation of nickel metal was observed. It was also shown that the thermal history of the powder had an important bearing on the results obtained − in general, preheating led to lower reduction rates. On a etudie experimentalement la reduction du sulfur de nickel (Ni3S2) en poudre par l'hydrogene, sous la pression atmospherique et a une echelle de temperature de 475 a 630°C. On a trouve la cinetique intrinseque veritable de la reaction en question et ce, dans des conditions qui permettaient l'application du modele a coeur de contraction topochimique dans le systeme de contrǒle chimique. Pour l'echelle de temperatures comprises entre 475 et 530°C, on a pu exprimer la constante du taux de reaction par l'equation suivante: Au-dessus de 530°C, on a observe la formation de “pleurage” (whiskers) de nickel metallique. On a aussi constate que les antecedents thermiques de la poudre avaient un effet important sur les resultats obtenus: en general, un chauffage prealable des taux de reaction moindres.
Effects of explicit phonics instruction on the decoding, spelling and comprehension skills of bilingual students making the transition to English reading

The purpose of this study was to examine the effects of explicit phonics instruction, embedded in a balanced literacy approach, on the English reading abilities of bilingual students making the transition from Spanish to English literacy. Ten Hispanic bilingual second-grade students participated in this study, including four males and six females. Students were preand post-tested on measures of phonics, word reading accuracy and comprehension. Over the course of six weeks, students participated in a balanced literacy instructional program that included instruction in spelling, vocabulary, phonics and comprehension. These areas were then assessed on a weekly basis. The intervention resulted in students’ improved comprehension, spelling and vocabulary abilities; however, a clear need for additional systematic, explicit English phonics instruction was also apparent. EXPLICIT PHONICS INSTRUCTION FOR ELLS 4 Table of
An austempering study of ductile iron alloyed with copper

Austempered ductile iron (ADI) has proved to be an excellent material as it possesses attractive properties: high strength, ductility and toughness are combined with good wear resistance and machinability. These properties can be achieved upon adequate heat treatment which yields the optimum microstructure for a given chemical composition. In this paper the results of an investigation the austempering of ADI alloyed with 0.45 % Cu for a range of times and temperatures are reported. The microstructure and fracture mode developed throughout these treatments have been identified by means of light and scanning electron microscopy and X-ray diffraction analysis. It was shown that the strength, elongation and impact energy strongly depend on the amounts ofbainitic ferrite and retained austenite. Based on these results, and optimal processing window was established.
Kinetics and Isotherms for Aqueous Lead Adsorption by Natural Minerals

The low grade (<15% P2O5) carbonatic rock phosphate and hydroxy aluminosilicate based mineral (pyrophyllite) of Madhya Pradesh (India) were investigated as adsorbents for their possible application for the removal of aqueous lead under static system. The kinetics and effect of temperature on adsorption of lead ions on the above two natural minerals have been studied. The adsorption process follows first-order kinetics and the rate of adsorption and film transfer coefficients are observed to decrease with increase in initial concentration of lead ions in solutions. It has been found that these natural minerals are effective in removing 65−99% of lead ions from 5.0 to 500 mg/L lead solutions. The Langmuir adsorption isotherm was used to represent experimental data for carbonatic rock phosphate whereas the Freundlich adsorption isotherm was found suitable to represent data for pyrophyllite. The adsorption process is found to be endothermic in the case of pyrophyllite and exothermic in the case of carbonatic .
Measurement of vibrationally excited N2(v) in an atmospheric-pressure air pulsed corona discharge using coherent anti-Stokes Raman scattering

Vibrationally excited N2(v = 1, 2) in an atmospheric-pressure air pulsed corona discharge was measured using coherent anti-Stokes Raman scattering (CARS). In a dry air discharge, the vibrational temperature determined from the ratio N2(v = 2)/N2(v = 0), Tv2, was approximately 500 K higher than that determined from N2(v = 1)/N2(v = 0), Tv1, immediately after the discharge pulse. Both vibrational temperatures reached equilibrium within 100 μs after the discharge pulse by the vibration-to-vibration (V-V) process of N2-N2. The translational temperature was also measured using CARS. The rise in the translational temperature due to vibration-to-translation (V-T) energy transfer was not observed for a postdischarge time of 5 μs–1 ms in the dry-air discharge. However, when the air was humidified, a significant V-T energy transfer was observed. It was due to an extremely rapid V-T process of H2O-H2O following the V-V process of N2-H2O. Measurements showed that the humidification of the ambient air accelerated the .
Formation of nickel silicide and germanosilicide layers on Si(001), relaxed SiGe∕Si(001), and strained Si/relaxed SiGe∕Si(001) and effect of postthermal annealing

This study compared the formation of nickel silicide or germanosilicide layers on various SiGe based heterostructures as well as the effects of the different annealing schemes (one-step versus two-step annealing) on the morphological, structural, and electrical properties. Uniform nickel silicide or germanosilicide layers were first formed by rapid thermal annealing of various heterostructures. The two-step annealing process of the samples first at 400°C (TA1) and subsequently at between 600 and 800°C (TA2) led to an increase in the sheet resistance, which was attributed to the formation of a high-resistivity NiSi2 phase, the agglomeration of the silicide or germanosilicide layers, and the formation of an amorphous interlayer between the silicide or germanosilicide layers. The lower sheet resistance of the silicide or germanosilicide layers formed on the relaxed-Si1−xGex (x=0.15)∕Si(001) substrates by two-step annealing compared with that of the samples formed on the strained Si/relaxed SiGe∕Si(001) and S.
A Study on the Action of Ozone on Multiwall Carbon Nanotubes

Abstract The functionalization of the surface of multiwall nanotubes (MWNTs) is the first step for the synthesis of more complex supramolecular structures and for their application by attaching molecules, macromolecules and biologically active molecules. Here we show in detail a couple of methods for introducing oxygenated surface groups on MWNTs by room temperature ozonization. The reaction kinetics between MWNTs and O3 has been studied in static conditions inside an IR gas cell. The pseudofirst order rate constant has been determined and compared with those of other carbon materials. MWNTs appear as the most reactive carbon materials with ozone, producing CO2 and even CO in certain special conditions when treated with a stream of ozonized oxygen. The ozonization reaction is strongly exothermic and conforms to the Elovich equation, an equation normally employed for the gas‐solid oxidation kinetics and the chemisorption of gases over solid surfaces. The ozonized MWNTs have been characterized qualitatively by FT‐IR spectroscopy and different types of ketonic groups have been detected although the most common has been found the carboxyl moiety. The quantitative analysis of ozonized MWNTs has been made by thermogravimetric analysis under N2 flow.
EXCHANGEABLE BASES OF MATURE, WELL‐DRAINED SOILS IN RELATION TO RAINFALL IN EAST AFRICA

Summary At low levels of annual rainfall, leaching of bases with falling percentage saturation follows a simple physical pattern, but as rainfall rises above a level sufficient for reasonable plant growth, intrusion of the biological factor leads to a recirculation of bases and even to an accumulation in the solum with the result that percentage saturation rises once more to an optimum at about 46 in. rainfall and falls away with further increase in rainfall. These changes in percentage saturation are independent of the base-exchange capacity of the parent material, and the total exchangeable bases in a soil are determined by the base-exchange capacity of the parent material and the rainfall regime to which it has been subjected.
Effects of Salting and Drying on Shark (Carcharhinus sorrah) Meat Quality Characteristics

The effect of drying method and pretreatment with salt on the properties of shark meat was investigated. Water loss during the salting step was faster with dry salting than with brine salting; however, both methods led to the same final water content at the end of the drying process. Moisture desorption isotherms showed that addition of salt prior to sun or air drying resulted in lower equilibrium moisture contents at the same water activity levels. Salting and method of drying had significant effects on the microbial load. Osmo-air-dried samples showed better microbial quality than samples treated by other methods. Molds grew on all samples after two months of storage at room temperature. Color and rehydration ratio were affected by the drying method. Higher dehydration ratios were obtained with air drying.
Examining Aggressiveness Levels of High School Students Whose Parents Have Different Attitudes in Terms of Various Variables

Bu arastirmada, ana-baba tutumlari farkli lise ogrencilerinin cinsiyet, yas, okul turu, anne-babanin ogrenim durumu ve ailenin gelir duzey degiskenler ine gore saldirganlik duzeyleri incelenmistir. Arastirmanin orneklem in i 1996-199 7 : egitim-ogretim yilinda Ankara ’nin Yenim ah aile: ilcesinde bulunan yedi fark! i lisede okuyan 465 ogrenci olusturmustur: ogrencilere iliskin: veriler arastirmaci tarafindan :gelistirilen Saldirganlik Olcegi, Kisisel Bilgi Formu ve Bilal (1984) tarafindan gel istir it en Ana-Baba Tutum Olcegi ile elde \ edilmistir. Verilerin cozumlenmesinde Iki Yonlu Varyans Analizi ve Scheffe testi kullanilmistir. Sonuc olarak, ana-baba tutumu ile cinsiyet, yas, okul turu, anne-babanin Ogrenim durumu ve ailenin gelir duzeyi degiskenlerinin v saldirganlik:: duzeyine: ortak : etkileri anlamli bulunmazken; cinsiyet ve okul turu degiskenlerinin saldirganlik duzeyine temel etkileri anlamli bulunmustur. Elde edilen bulgular literatur isiginda tartisilmis ve bazi onerilerde bulunulmustur.
Mo/Al/Mo/Au Ohmic contact scheme for AlxGa1-xN/GaN high electron mobility transistors annealed at 500 °C

Low-resistance Ohmic contacts on Al0.3Ga0. 7N∕GaN high electron mobility transistors (HEMTs) were formed with a Mo∕Al∕Mo∕Au metallization scheme which was annealed at a relatively low temperature of 500 °C. A contact resistance of 0.11±0. 05Ωmm and a specific contact resistivity of 2.63×10−7Ωcm2 were achieved. This represents the best low-temperature-annealed Ohmic contacts on GaN-based HEMTs achieved to date.
Thermal conductivity reduction in oxygen-deficient strontium titanates

We report significant thermal conductivity reduction in oxygen-deficient lanthanum-doped strontium titanate (Sr1−xLaxTiO3−δ) films as compared to unreduced strontium titanates. Our experimental results suggest that the oxygen vacancies could have played an important role in the reduction. This could be due to the nature of randomly distributed and clustered vacancies, which would be very effective to scatter phonons. Our results could provide a pathway for tailoring the thermal conductivity of complex oxides, which is very beneficial to various applications including thermoelectrics
An Isotachophoretic Model of Counteracting Chromatographic Electrophoresis (CACE)

Abstract Counteracting chromatographic electrophoresis (CACE) is a new electrophoretic technique for preparative separation of charged macromolecules, particularly proteins. CACE combines gel chromatography of a protein sample in a packed bed of gel beads having a gradient of exclusion limit, simultaneously with electrophoresis in an electric field tending to move the protein upstream. The target protein's convective movement opposes its electrophoretic movement, focusing the protein into an accumulation zone where its net velocity is zero. A mathematical model of concentrations and electrical fields in CACE was derived from an analogy to isotachophoresis. Accumulation-zone concentrations, electrical field, and pH were calculated from the bulk flow and electrophoretic fluxes of the target protein and buffer constituents, along with expressions for charge conservation and electroneutrality. The model predicts conditions for formation of protein accumulation zones given column operating parameters and mobil.
Spectroscopy and photokinetics of chromium (III) in glass

The optical absorption, emission, emission lifetime, and absolute quantum efficiency have been measured for chromium (III) in a wide variety of oxide and fluoride glasses. In all cases, the room temperature emission is dominated by inhomogeneously broadened 4T2 fluorescence, and the relaxation of this level is shown to be primarily nonradiative. Multiphonon emission to lattice modes, concentration quenching, and quenching by hydroxyl moieties is shown not to be of significance in this relaxation at low doping levels. Instead, it is proposed that the radiationless process involves primarily local modes associated with the CrX6 cluster and is sensitive to site symmetry.
Studies on the extraction of uranium by N-octanoyl-N-phenylhydroxamic acid

Summary N-octanoyl-N-phenylhydroxamic acid (OHA) has been prepared by partial reduction of nitrobenzene with Zn dust/NH4Cl, followed by acylation with n-octanoyl chloride. Structure of OHA was confirmed by 1H NMR, IR spectra and CHNS microanalysis. The extraction of uranium by OHA has been studied as a function of pH, temperature and concentration of OHA. The extraction of uranium was found to increase with increase in pH. Uranium forms a 1:2 complex with OHA. IR Spectra & NMR Spectra of the uranium-OHA complex and slope analysis obtained from extraction studies indicated that the extraction of uranium was due to the formation of a chelate. The enthalpy change accompanied by the extraction of uranium by OHA has been obtained by temperature variation method. The extraction process was found to be endothermic at pH 2 and exothermic at pH 6.
Factors which affect retention of Salmonella by chicken muscle fascia

Retention of Salmonella lyphimurium and Salmonella Singapore by chicken muscle fascia after immersion in bacterial suspensions was directly dependent on the concentration of bacteria in suspension. However, more bacteria were retained by tissue immersed in suspensions for 30 min compared with tissue immersed only transiently (ca 15 s) and no significant difference in retention of either test strain used was noted for suspensions prepared in distilled water or physiological saline. Differences in numbers of bacteria retained were correlated with water induced changes in tissue microtopography. By comparison, addition of sodium or magnesium ions (present as chlorides) in concentrations greater than 0.2mol. l‐1, caused significant reductions in retention. Furthermore, optimal retention of both strains occurred at a pH of ca 7. Cells of the test strains used did not attach to collagen fibres associated with fascia when suspension media other than distilled water were used. Treatment of tissue with cetyl pyridi.
Caracterização etnopedológica de Planossolos utilizados em cerâmica artesanal no Agreste Paraibano

Classic ethnoscientific techniques were adapted to describe and analyze the knowledge of peasant potters about soils they use for making pottery in a rural village in the Agreste region, State of Paraiba, northeastern Brazil. Five soil profiles from pits where local people obtain pottery clay were formally described by researchers (etic approach) and by peasant artisans (emic approach). Samples collected during both the emic and etic approaches were used for the morphological and analytical soil characterization. The peasant potters were able to distinguish, identify, and name soil materials arranged in layers along the soil profiles, somehow comparable to the arrangement of the pedogenetic horizons. Vision, touch and taste are used by local potters to evaluate the quality of pottery clay. Among the soil profiles described near clay pits, four were classified as Haplic Solonetz, and one as Eutric Planosol, according to the FAO/UNESCO legend. Ethnopedological studies in different social and pedological environments could contribute to the advancement of soil science and are an opportunity for an improvement in the understanding and appreciation of soil knowledge and management by peasant potters.
Synthesis of Reaction Mechanisms Consisting of Reversible and Irreversible Steps. 1. A Synthesis Approach in the Context of Simple Examples

The analysis of pseudo-steady states of a chemical system can be aided by the identification of mechanisms responsible for overall reactions, from a known set of elementary steps that involve overall reactants and products as well as reaction intermediates. In the context of examples of catalytic synthesis of ammonia and methanol, an alternative approach for the construction of mechanims from steps is presented. The approach is based on successive processing and elimination of reaction intermediates which should not appear in the net stoichiometry of the overall reactions accomplished
Seismic Response of Multistory Buildings with Double Telescoping Self-Centering Energy-Dissipative Brace (DT-SCED)

Telescopic Self-Centering braces are one of the very successful examples of Self-Centering braces which perform well in seismic loading. In this study, a new example of Telescopic Self-Centering brace is introduced, which has superior features over other telescopic braces. These include: high axial load capacity, use of shorter cables in brace construction, simplicity of construction, use of separate cables for compressive and traction modes, less fatigue in cyclic loads and, allowing for more dynamic loading cycles. In this paper, a sample was designed with an axial force capacity of 300kN. Modeling of behavior (DT-SCED) was accurately expressed using numerical relationships. nonlinear incremental stiffness analysis method was also used to calculate the hysteresis brace behavior. The cyclic load test was applied to this brace and the result showed complete Self-Centering behavior. Then, a sample building with the double telescoping Self-Centering Energy-Dissipative Brace (DT-SCED) was subjected Single direction pushover analyses and the results are compared with the sample buildings with the Self-Centering Energy-Dissipative Bracing (SCED) and the Telescoping Self-Centering Energy-Dissipative Bracing (T-SCED). The results of the analysis and comparing with other samples confirm the seismic superiority of performance of the DT-SCED brace over other samples.