Miracle-dz/UniFAR-FTUs huggingface dataset:
Characterisation of Soils by the near Infrared Technique

There are physical, physico-chemical and chemical parameters which can be used as a basis for the characterisations of soils. Some of these characterisation methods are slow, laborious and show very empiric character. Near infrared (NIR) reflectance spectroscopic methods were used for substitution of conventional soil analysis procedures. Seven different soil characteristics (humus, calcium carbonate, total nitrogen, dead water content, yarn test by Arany, mechanical composition, hygroscopic water content) were measured by NIR using Hungarian and ISO standards as reference methods. It was concluded that the humus content, which measures the total organic content of soil can be predicted from NIR spectra with good accuracy (SEP = 0.3%). There are two parameters (mechanical composition and hygroscopicity) which showed significant correlation with the changes in the status of water in soil and they were detectable with acceptable accuracy based on their NIR spectra. The other four parameters were not predictable either due to the lack of spectroscopic information or to the poor quality of reference methods. The developed method was very sensitive to the physical status of samples and an accurate standard sample preparation was needed. Spectral libraries were developed and validated for a quick and non-destructive qualification and selection of soil samples.
Internally Modified Halloysite Nanotubes as Inorganic Nanocontainers for a Flame Retardant

Inst itute for M cromanu actur ng, Lou sana Tech Un vers ty, Lou ana 71272, USA(Received October 28, 2012; CL-121098; E-mail: takahara@cstf.kyushu-u.ac.jp)We have selectively hydrophobized halloysite nanotubelumens for eﬃcient loading with a ﬂame retardant for controlledreleasing composite materials. The inner lumen of octadecyl-phosphonic-acid-modiﬁed halloysite was loaded with hydro-phobicbisphenol-A bis(diphenyl phosphate). This ﬂameretardant was released from the clay nanotubes in linear fashionover 60h demonstrating the system potential utility as eﬀectivenanocontainers for smart composite systems.There has been considerable interest in materials based onaluminum silicate nanotubes because of theirunique featuresand applications.
Flow injection analysis with amperometric detection for morpholine determination in corrosion inhibitors

In this study, an electrochemical method is proposed using flow injection analysis and amperometric detection with screen-printed carbon electrodes for morpholine determination to monitor the quality of morpholine-based commercial inhibitors and the residual concentration of inhibitors that control internal corrosion in oil industry pipelines. The amperometric method resulted in a strong linear correlation coefficient (r = 0.9941) with a linear response over a concentration range of 20-120 mg L-1, a limit of detection of 10 mg L-1 and a limit of quantification of 30 mg L-1. In addition, the method has been shown to be precise, linear and homoscedastic. The recovery for the amperometric method was 100 ± 6%, and the recovery for the real condensate sample was 99 ± 2%. Thus, the proposed method is promising for analysing morpholine-based commercial inhibitors in oil industry pipelines with simple and low-cost methodologies compared with ion chromatography techniques.
Model for the clustering of multiplets in ionomers

Le modele presente peut etre qualifie de «quasi cristallin»; les amas presentent un ordre, comme un petit cristal, dont l'organisation est affectee par la presence des chaines, les amas eux-memes sont ordonnes dans un hypercristal avec une grande maille
Aroma of minor tropical fruits

Publications on the volatile composition of some minor tropical fruits, i.e. acerola, cupuacu, soursop, bacuri, genipap, umbu-caja, araca-boi, camu-camu, umbu, murici and cashew apple, are reviewed. Differences observed in the volatile composition of a same fruit could be due to the methodology and[sol ]or to different cultivars or geographical regions. Bound volatiles can also be liberated during the extraction procedures under drastic conditions. Copyright © 2005 John Wiley & Sons. Ltd.
Dispersion Characteristics and Rheology of Organoclay Nanocomposites Based on a Segmented Main-Chain Liquid-Crystalline Polymer Having Pendent Pyridyl Group

The dispersion characteristics and rheology of organoclay nanocomposites based on a thermotropic liquid-crystalline polymer (TLCP) having pendent functional group were investigated using X-ray diffraction (XRD), transmission electron microscopy (TEM), and oscillatory shear rheometry. For the study, a segmented main-chain TLCP having pendent pyridyl group (PyHQ12) was synthesized and, for comparison, another segmented main-chain TLCP having pendent phenylsulfonyl group (PSHQ12) was synthesized, both TLCPs having the identical chemical structure for the main-chain backbone. The differences in phase transition temperature and rheological behavior observed between PyHQ12 and PSHQ12 are explained in terms of the self-associating characteristics of the pendent pyridyl group in PyHQ12. PyHQ12 and PSHQ12 were used to prepare nanocomposites with two commercial organoclays: one (Cloisite 30B) was natural clay (montmorillonite) treated with a surfactant (MT2EtOH) having hydroxyl groups, and the other (Cloisite 20A).
Phosphorus partitioning between olivine and melt: An experimental study in the system Mg2SiO4-Ca2Al2Si2O9-NaAlSi3O8-Mg3(PO4)2

Abstract The partitioning of phosphorus between olivine and melt was measured by conducting partitioning experiments within the system Mg2SiO4-Ca2Al2Si2O9-NaAlSi3O8-Mg3(PO4)2, using olivines crystallized with cooling rates in the range 1 to 10 °C/h. Partition coefficients, DPol/melt, vary from 0.05 to 1.41 and are strongly influenced by melt composition, with high partition coefficients observed for more polymerized melts. Correlations between elemental abundances in the olivines demonstrate that phosphorus substitutes on a near one for one basis for Si, charge-balanced by Mg vacancies; no correlation between P and Al concentration in the olivine was observed. A complete understanding of the controls on DPol/melt is required to model quantitatively the zoning of P in olivine that has recently been shown to be a common feature of igneous olivine crystals. The strong melt compositional dependence observed in this study implies that both changing concentrations of P in the melt during fractionation, and changing values of DPol/melt can contribute to core-to-rim variations in P when the surface composition of a growing olivine crystal is in equilibrium with the melt. The common observation of zones in natural olivines where high P is correlated with high Al and Cr must be explained by processes other than equilibrium growth and, as suggested previously, such zones are probably related to solute trapping during episodes of rapid growth.
Amperometric determination of organophosphorus pesticide by silver electrode using an acetylcholinesterase inhibition method

An amperometric method for the detection of organophosphorus pesticide based on acetylcholinesterase inhibition is reported. A silver electrode is used and shows an inherent advantage in determination of pesticides, which can monitor the activity of the enzyme in real time by electrochemical oxidization of thiocholine at low potential. Cyclic voltammetry and amperometry were used to evaluate the performance of silver electrode for thiocholine detection. Spectrophotometry was conducted to optimize the parameters for the enzymatic reaction. Cyclic voltammetry shows the advantages of silver over others (platinum, glassy carbon and gold) electrodes, when detecting thiocholine at low potentials. The silver electrode could linearly respond to thiocholine in the range from 5.2 × 10−7 to 2.6 × 10−5 M at 0.08 V. The measurement displayed a detection limit of 6.2 ppb. The analytical feasibility was investigated further via determination of paraoxon in Chinese cabbages and Fuji apples, which shows recovery rates of 92.05% and 106.11%, respectively. The results indicate the capability of the proposed method for pesticides monitoring in real samples.
Simplified Onsager theory for isotropic-nematic phase equilibria of length polydisperse hard rods

Polydispersity is believed to have important effects on the formation of liquid crystal phases in suspensions of rodlike particles. To understand such effects, we analyze the phase behavior of thin hard rods with length polydispersity. Our treatment is based on a simplified Onsager theory, obtained by truncating the series expansion of the angular dependence of the excluded volume. We describe the model and give the full phase equilibrium equations; these are then solved numerically using the moment free energy method which reduces the problem from one with an infinite number of conserved densities to one with a finite number of effective densities that are moments of the full density distribution. The method yields exactly the onset of nematic ordering. Beyond this, results are approximate but we show that they can be made essentially arbitrarily precise by adding adaptively chosen extra moments, while still avoiding the numerical complications of a direct solution of the full phase equilibrium conditions. We investigate in detail the phase behavior of systems with three different length distributions: a (unimodal) Schulz distribution, a bidisperse distribution, and a bimodal mixture of two Schulz distributions which interpolates between these two cases. A three-phase isotropic-nematic-nematic coexistence region is shown to exist for the bimodal and bidisperse length distributions if the ratio of long and short rod lengths is sufficiently large, but not for the unimodal one. We systematically explore the topology of the phase diagram as a function of the width of the length distribution and of the rod length ratio in the bidisperse and bimodal cases.
The chemistry of antiwear films generated by the combination of ZDDP and MoDTC examined by X-ray absorption spectroscopy

In order to obtain a better understanding of the decomposition mechanisms of antiwear and antioxidant engine oil additives such as zinc dialkyldithiophosphate (ZDDP) and molybdenum dithiocarbamate (MoDTC), tribochemical and thermally deposited films were prepared from oil solutions containing varying concentrations of these two additives. The chemistry of these films was studied by using X-ray absorption (XANES) spectroscopy and X-ray photoelectron (XPS). The antiwear properties were examined on a Plint rubbing machine by measuring the amount of wear as a function of time and the concentrations of the additives. The XANES and XPS spectra indicate that the dominant species from MoDTC in the antiwear films resembles that of a MoS2-like film, and in the thermal films, the dominant species are those of a sulphate and MoO3. The spectra also indicate that the phosphorus from ZDDP forms polyphosphate chains of varying lengths. The combined use of organo-Mo compounds and Zn alkyl dithiophosphates showed a synergi.
Studies on Transport of Anionic Complex of Plutonium From Nitric Acid Medium across ALIQUAT 336/n-Paraffin Liquid Membrane

The present studies deal with the application of the supported liquid membrane (SLM) technique for the separation and purification of plutonium from other impurities in nitric acid medium using anion exchanger Aliquat 336 (a quaternary ammonium salt)/ n-paraffin as a carrier. The effects of feed acidity, stripping agent, and membrane pore size and membrane thickness on the transport behavior of anionic complex of plutonium have been studied in detail. An attempt has been made to establish the mechanism for plutonium transport and model the physicochemical transport of plutonium across SLM. Transport of anionic complex of plutonium increased with increase in carrier concentration upto 10% (w/v), while with further increase in carrier concentration, decrease in transport of plutonium was observed. The PTFE membrane with 0.45 µm pore size and 80 µm thickness was found to be most suitable for the transport of plutonium. The effect of membrane thickness indicates that the transport phenomenon is diffusion controlled. Transport behavior of plutonium, uranium, and other fission products from actual feed solution of ion exchange method obtained in PUREX process was also tested and the result clearly indicates that Aliquat 336 has high selectivity for plutonium and it can be used for the separation and purification of plutonium by the supported liquid membrane technique.
Effect of Domain Boundary on Carrier Transport of Calamitic Liquid Crystalline Photoconductive Materials

Abstract Smectic mesophases in the calamitic liquid crystalline materials such as 2-phenylnaphthalene derivatives exhibit fast ambipolar carrier transport, whose mobility is up to 10−2 cm2/Vs. For these mesophases, we have investigated the effect of defects in the bulk and at the domain boundary on these carrier transport by measuring transient photocurrents in thick cells up to 120 μm in thickness and in the cells of different domain sizes of 10–100s μm. It was found that non-dispersive carrier transports was observed for all the cells and the carrier transport was affected neither by cell thickness nor by domain sizes. Thus, it was concluded that there are few deep defects in the bulk and that the domain boundary is electrically inactive in these mesophases, demonstrating their high potential for practical application to large-area electronic devices.
Quantitative composition of cold-pressed orange oils

One early-season, two midseason, and four lateseason cold-pressed orange oils were analyzed quantitatively by gas chromatography (glc) on a nonpolar column where glc response factors and percent nonvolatile material were determined to afford weight percent for each of the 17 main oil components. Lateand midseason oils were similar in composition by this analysis, although lateseason oil is considered a better flavoring ingredien t for orange products. The early oil had smaller quantities of linalool and of some aldehydes than the others, A synthetic mixture of 15 components prepared for response factor determinations had a citrus-like aroma, but it was not like that of coldpressed orange oil. The octanal to decanal ratio (measured on a polar column) and the citral to saturated aldehyde ratio in orange oil were comparable to earlier reported results.
Carrier energy relaxation by means of Auger processes in InAs/GaAs self-assembled quantum dots

Carrier relaxation processes are investigated in self-assembled InAs/GaAs quantum dots using time-resolved photoluminescence spectroscopy. The quantum-dot photoluminescence rise time has been measured as functions of carrier excitation density and excitation wavelengths. The measured relaxation time is about 32 ps at low excitation density and decreases by 1 over the excitation density from about 3 W/cm2, under nonresonant laser excitation. The threshold of this density-dependent regime occurs at a slightly higher density as the excitation wavelength increases and it disappears when the photon pumping energy is below the wetting layer barrier energy. These results clearly establish the regime where Auger processes become the dominant carrier relaxation mechanism in these self-assembled quantum dots.
STUDI KOMPETENSI KEMAMPUAN MENULIS DI KALANGAN MAHASISWA

This research aimed to know the student’s skill in writing scientific-papers, by reviewing to some aspects (1) the ability in developing scientific-papers content, (2) the ability in organizing the scientific-papers, (3) the ability in using scientific-papers terms and vocabularies, (4) The ability in using scientific languages in scientific-papers and (5) the ability to apply an orthography and writing techniques in scientific-papers. This research used descriptive methods. The result of this research showed that (1) the student’s scientific-papers writing abilities reviewed from how they develop scientific papers content was considered sufficient. (2) The student’s scientific-papers writing abilities reviewed through how they organize scientific-paper was sufficient. (3) The student’s scientific-papers writing abilities reviewed through their ability in using scientific-papers terms and vocabularies was sufficient. (4) The student’s scientific-papers writing abilities review through the aspect of using scientific languages was sufficient. (5) The student’s scientific-papers writing abilities review through apply an orthography and writing techniques scientific-papers was also sufficient.
Morphology control of bimetallic nanostructures for electrochemical catalysts

Abstract Bimetallic nanostructures with well-defined shapes have shown distinct and advantageous catalytic properties compared to their monometallic counterparts. The use of bimetallic electrocatalysts may improve activity and durability, in addition to the possibility of reducing the loading of precious metals. A variety of bimetallic nanocrystals with different shapes has been reported in recent years. Their activities toward electrochemical catalytic reactions such as oxygen reduction and alcohol oxidations have been intensively studied. In this review, we discuss some latest developments in the morphology-controlled synthesis of Pt- and Pd-based bimetallic nanocrystals with shapes such as nanodendrites, polyhedra, porous hollow structures, and core shells, as well as their applications as electrochemical catalysts.
Synthesis of Biodiesel via Acid Catalysis

Biodiesel is synthesized via the transesterification of lipid feedstocks with low molecular weight alcohols. Currently, alkaline bases are used to catalyze the reaction. These catalysts require anhydrous conditions and feedstocks with low levels of free fatty acids (FFAs). Inexpensive feedstocks containing high levels of FFAs cannot be directly used with the base catalysts currently employed. Strong liquid acid catalysts are less sensitive to FFAs and can simultaneously conduct esterification and transesterification. However, they are slower and necessitate higher reaction temperatures. Nonetheless, acid-catalyzed processes could produce biodiesel from low-cost feedstocks, lowering production costs. Better yet, if solid acid catalysts could replace liquid acids, the corrosion and environmental problems associated with them could be avoided and product purification protocols reduced, significantly simplifying biodiesel production and reducing cost. This article reviews some of the research related to biodi.
MHD Flow Control and Power Generation in Low-Temperature Supersonic Flows

The paper presents results of cold MHD flow deceleration and MHD power generation experiments using repetitively pulsed, short pulse duration, high voltage discharge to produce ionization in M=3 nitrogen and air flows. MHD effect on the flow is detected from the flow static pressure measurements. Retarding Lorentz force applied to the flow produces a static pressure increase of up to 17-20%, while accelerating force of the same magnitude results in static pressure increase of up to 5-7%. No discharge polarity effect on the static pressure was detected in the absence of the magnetic field. The fraction of the discharge input power going into Joule heat in nitrogen and dry air, inferred from the present experiments, is low, α=0.1, primarily because energy remains frozen in the vibrational energy mode of nitrogen. Comparison of the experimental results with the modeling calculations shows that the retarding Lorentz force increases the static pressure rise produced by Joule heating of the flow, while the accelerating Lorentz force reduces the pressure rise. This result provides first direct evidence of cold supersonic flow deceleration by Lorentz force. The experiments have also shown that at the present conditions, electric current in the MHD power generation regime is very low, of the order of 1 mA. This is entirely due to the bottleneck effect of the non-self-sustained discharge cathode layer, at the conditions when the MHD open voltage is significantly lower than the cathode voltage fall. Adding an easily ionizable species to the flow (C9H15N at 0.1% level) did not result in the flow conductivity increase, both because of seed condensation in the cold supersonic flow and a low seed fraction. Kinetic modeling calculations of the pulser-sustainer MHD discharge demonstrate that (i) low open voltages reduce MHD currents by more than two orders of magnitude, and (ii) this effect cannot be circumvented by seeding the flow at feasible levels or by using electrodes with high secondary emission coefficient. Based on the results of the present experiments and modeling calculations, the only feasible approach to extracting MHD power at low flow temperatures is to increase the MHD open voltage to the value comparable with the discharge cathode voltage fall.
Study of the thermal degradation of poly(N‐vinyl‐2‐pyrrolidone) by thermogravimetry–FTIR

The thermal degradation of poly(N-vinyl-2-pyrrolidone) (PVP) was studied by dynamic thermogravimetric analysis (TGA) in the range 200–600°C under nitrogen and oxygen atmospheres at various heating rates. The apparent activation energy of the degradative process was determined by the application of kinetic treatments, giving an average value of 242 kj/mol in N2, whereas in the presence of oxygen, two trends may be considered: At relatively low temperatures (200–400°C) and degrees of conversion, α, lower than 0.5, we obtained an average value of 199 kj/mol, whereas in the temperature interval 400–600°C with degrees of conversion higher than 0.5, the value of Ea was 306 kj/mol. Isothermal experiments carried out in N2 in the interval 350–400°C gave an average value of Ea = 231 kj/mol, in good agreement with that obtained from dynamic treatments. The FTIR spectra of the volatile compounds evolved in degradation experiments carried out in N2 as well as in the presence of oxygen suggest that PVP is thermally degraded, predominantly, by the release of the pyrrolidone side group and the subsequent decomposition of polyenic sequences. © 1993 John Wiley & Sons, Inc.
Synthesis and characterization of the biodegradable copolymers from succinic acid and adipic acid with 1,4-butanediol

Biodegradable homopolyesters such as poly(butylene succinate) (PBSU) and poly(butylene adipate) (PBAD) and copolyesters such as poly(butylene succinate-co-butylene adipate) (PBSA) were synthesized, respectively, from succinic acid (SA) and adipic acid (AA) with 1,4-butanediol through a two-step process of esterification and deglycolization. The polyester compositions and physical properties of both homopolyesters and copolyesters were investigated by 1H– and 13C–NMR, DSC, GPC, WAXD, and optical polarizing microscopy. The melting point (Tm) of these copolyesters decreased gradually as the contents of butylene adipate increased and the glass-transition temperature (Tg) of these copolyesters decreased linearly as the contents of the adipoyl unit increased. PBSA copolyesters showed two types of XRD patterns of PBSU and PBAD homopolyesters. Furthermore, the biodegradation and hydrolytic degradation of the high molecular weight PBSU homopolyester, PBAD homopolyester, and PBSA copolyesters were investigated in the composting soil and NH4Cl aqueous solutions at a pH level of 10.6. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2808–2826, 2001