Miracle-dz/UniFAR-FTUs huggingface dataset:
X‐ray structure determination of new monomers to establish their polymerizability: Copolymerization of two tetrasubstituted electrophilic olefins with electron‐rich styrenes giving polymers with an average 1.25 functional groups per chain carbon atom

X-ray crystal structure determination for two tetrasubstituted electrophilic olefins, tetramethyl ethylenetetracarboxylate TMET and dimethyl dicyanofumarate DDCF, revealed two fundamentally different molecular structures. TMET is a nonplanar molecule that possesses two opposite ester groups planar and the others above and below the molecular plane. In contrast, DDCF is a molecule for which both ester groups lie in the plane of the double bond and nitrile groups. DDCF underwent thermal spontaneous copolymerization with electron-rich styrenes to give 1:1 alternating copolymers in moderate yields and molecular weights. These copolymers, which result from the first copolymerization of a tetrasubstituted olefin, possess an average functionality of 1.25 per chain carbon atom. Polymerization is made possible by low steric hindrance and the high delocalization in the propagating radical. The yields were limited by competing cycloaddition reaction. The corresponding diethyl ester also copolymerized, but not so well. Neither electrophilic olefin homopolymerized under . gamma. -irradiation. TMET did not copolymerize at all when treated under identical conditions.
Quantum-Confined Stark Effect due to Piezoelectric Fields in GaInN Strained Quantum Wells

We have studied the influence of piezoelectric fields on luminescence properties of GaInN strained quantum wells. Our calculation suggests that an electric field of 1.08 MV/cm is induced by the piezoelectric effect in strained Ga0.87In0. 13N grown on GaN. The photoluminescence peak energy of the Ga0.87In0. 13N strained quantum wells showed blue shift with increasing excitation intensity. Moreover, the well-width dependence of its luminescence peak energy was well explained when the piezoelectric fields were taken into account. These results clearly showed that the piezoelectric field induced the quantum-confined Stark effect.
Temporal, spatial, and resolution constraints for in situ sampling devices using diffusional equilibration : Dialysis and DET

The techniques of dialysis and diffusional equilibration in thin films (DET) are used to measure solute concentrations in sediment porewaters. Their performance was assessed using two-dimensional modeling with a view to establishing their limitations and providing guidelines for their application in the field and the subsequent interpretation of results. Three alternative types of supply to the samplers were considered: (i) where porewater solute concentrations are well buffered by desorption from or dissolution of the solid phase; (ii) where there is no resupply to the porewater apart from diffusion; (iii) where there is a partial resupply to the porewater from the sediment solid phase. Using typical sampler designs (DET gels 0.4 mm thick and peeper cells 6 mm deep), the times for 99% equilibration in the buffered case were calculated as 18 min and 36 h for DET and dialysis peepers, respectively. For the purely diffusive case, 99% equilibration times are 78 h (DET) and 1380 days (dialysis peepers). Experimentally observed equilibration times ( hours for DET, up to 2−3 weeks for peepers) lie between the modeled buffered and diffusive case values and are consistent with the modeled partial resupply from solid phase to porewater. The equilibration time is inversely proportional to the solute diffusion coefficient and increases with peeper cell depth or gel layer thickness. To ensure minimum equilibrium times in multiple depolyments, DET devices should be separated by >2 cm and peepers by >16 cm. Porewater concentration maxima and gradients are underestimated by both techniques, resulting in underestimations of vertical fluxes calculated from Fick's first law. DET performs better for a given width of a porewater maximum. As concentration maxima become wider, the fidelity of measured profiles is improved. The fidelity of peeper profiles is limited largely by the cell size and separation, and that of DET by slicing interval and gel/filter thickness. Peeper cell depth does not affect the measured peak concentrations, but increasing DET gel thickness underestimates measured peak concentrations. To minimize back-equilibration times for DET analysis, diffusional path lengths and eluent volumes should be as small as possible.
Wetting reaction versus solid state aging of eutectic SnPb on Cu

The reaction kinetics of eutectic SnPb solder on Cu were studied and compared in the liquid state at 200 to 240 °C and in the solid state aged at 125–170 °C. The ternary phase diagrams of SnPbCu, the morphology of intermetallic compound (IMC), and the kinetics of growth of the intermetallics were used in the comparison. The temperature difference between these two reactions is only 30 °C, but the kinetics of reaction, as well as the morphology of IMC formation, are very different. The kinetics in the wetting reaction is four orders of magnitude faster than that in solid state aging. The Cu6Sn5 intermetallic morphology in solid state aging is a layer type, but it has a scallop-type morphology in the wetting reaction. The morphology strongly affects the kinetics. While the kinetic difference can be attributed to the difference in atomic diffusivity between the liquid state and the solid state, it is the morphology that determines the kinetic path in these reactions. We conclude that a fast rate of reaction,.
Photooxidation of polystyrene: irradiation at 254 and 365 nm

Studies have been made of the near surface photooxidation of atactic polystyrene films prepared in the absence of air. The samples were photooxidized on exposure to air at two frequencies, 254 and 365 nm, using a calibrated mercury irradiation source with filters. Most studies were made at 40/sup 0/C and as a function of irradiation time with the reactions characterized by changes in molecular weight and composition. The former was evaluated by gel permeation chromatography and the latter by transmission Fourier transform infrared ir spectroscopy and by multiple-internal-reflectance ir spectra using different angles and different crystals to evaluate compositions as a function of film depth. Species identified in photooxidation include the generation of hydroperoxides and the appearance of carbonyl bands with the latter identified by the spectral shift associated with the exposure of the photooxidized polystyrene surface to ammonia. These results suggest that principal products of near-surface oxidation of polystyrene are carboxylic acids. 6 figures, 1 table.
Duplicate analysis in geochemical practice. Part I. Theoretical approach and estimation of analytical reproducibility

Duplicate analytical results can be used to give rapid and realistic estimates of precision in analytical systems. In particular the effects of varying concentration of analyte on the variance of the measurement can be taken into account. When only small numbers of duplicate observations are available, the precision can be rapidly tested against an empirical standard level by use of a special control chart. Some common data-recording practices, however, can lead to erroneous estimates of detection limit, irrespective of the estimation procedure employed.
Effectiveness of stone bunds in controlling soil erosion on cropland in the Tigray Highlands, northern Ethiopia

Abstract Use of stone bunds to enhance soil and water conservation was first introduced to Tigray, northern Ethiopia in 1981. This study was designed to examine the factors that control the effectiveness of bunds installed on cropland. Qualitative and quantitative assessments of soil loss and sediment accumulation were conducted on 202 plots at 12 representative sites in Dogu'a Tembien district. Mean annual soil loss from the foot of the bunds due to tillage erosion was estimated at 39kgm−1yr−1 or 20tha−1yr−1, a rate which decreased with increasing age of bund. The assessed mean annual soil loss rate by sheet and rill erosion in the absence of stone bunds is 57tha−1yr−1. The mean measured annual rate of sediment accumulation behind the stone bunds is 119kgm−1yr−1/sp or 59tha−1yr−1. The measurements show that the introduction of stone bunds to the region has led to a 68% reduction in annual soil loss due to water erosion. This reduction is due to the accumulation of sediment behind the stone bunds, which occurs faster in the early years after construction and decreases as the depression behind the bunds becomes filled with sediment. New stone bunds are particularly effective in trapping sediment in transport, but regular maintenance and increase in height of the bunds is necessary to maintain their effectiveness. The average USLE P factor for stone bunds in the study area is estimated to be 0.32.
Treatment of intershell correlation effects in ab initio calculations by use of core polarization potentials. Method and application to alkali and alkaline earth atoms

In the present approach the high reliability of ab initio techniques is combined with the easily amenable phenomenological core polarization concept for an efficient treatment of intershell correlation effects in all‐electron SCF and valence CI calculations. By use of only a single adjustable atomic parameter, which is related to the radius of the core and determines the cutoff at short range, our effective core polarization potential (CPP) accounts quantitatively for dynamical intershell correlation as well as exclusion effects on the correlation energy of the core. The applications refer to alkali and alkaline earth atoms (Li to K and Be to Ca) and a detailed analysis is performed for core polarization effects on ionization energies, electron affinities, oscillator strengths, polarizabilities, van der Waals coefficients, the valence electron density, and spin densities. Very accurate results are obtained for well‐known energetic properties and spin densities at the nucleus. With respect to the other app.
High‐pressure Raman study of dense methane: CH4 and CD4

High-pressure Raman spectra of liquid and solid CH4 and CD4 were measured up to 18 and 13 GPa, respectively, at 300 K in a gasketed diamond-anvil cell. On the basis of visual observations under the polarizing microscope and changes in the Raman spectra, it was confirmed that there are only two solid phases (I and VII) for CH4 and CD4 at 300 K up to 18 GPa; no solid-solid phase transition was found around 12 GPa, in contrast to earlier claims. In phase VII, some molecules are orientationally ordered, whereas others are orientationally disordered, just like the low-temperature solid phases II, III, IV and V.
USE OF PETIOLAR SAP NITRATE FOR ASSESSING NITROGEN STATUS OF IRRIGATED BRUSSELS SPROUT CROPS

ABSTRACT Four field experiments were carried out during 1992/93 (sites 1 and 2) and 1993/94 (sites 3 and 4) to assess the effects of nitrogen (N), at rates up to 600 kg N ha−1 on sap nitrate concentrations in petioles of the youngest fully expanded leaves (P-YFEL) of Brussels sprouts (Brassica oleracea L. var. gemmifera). The experiments were located in commercial plantings in the Mount Lofty Ranges of South Australia. Plant samples were collected at 2–4 week intervals from 4 to 28 weeks after the plants were transplanted. Temporal variation and the effect on sap nitrate concentration of sampling leaves next in age to the index leaf (YFEL−1 to YFEL+2), were also studied. Nitrate concentrations in the sap of P-YFEL showed poor sensitivity to variations in side-dressed N fertilizer and the magnitude of the changes varied between sites and sampling time. For example, at 12 weeks after transplanting, sap nitrate concentrations varied by less than 2,000 mg L−1 over the range of N applied. Nitrate concentrations in petioles also varied with the age of the leaf sampled. Nitrate concentrations in petioles sampled at 4, 6, 8, and 10 weeks after transplanting increased with leaf age. Linear and quadratic models were used to study the relationships between sap nitrate concentration in P-YFEL sampled during the period 4 to 24 weeks after transplanting and yield response to applied N. Significant relationships were only found at site 2, 8 weeks after transplanting, R2=0.98; site 3 at 18 weeks, R2=0.87 and site 4 at 8 and 10 weeks, R2=0.93 and 0.87, respectively. Based on lack of sensitivity (as indicated by the narrow range in petiolar sap nitrate concentrations in response to variations in N supply), temporal variation (changes in petiolar sap nitrate concentrations during the season) and the lack of consistent relationships between sap nitrate concentrations and yield response, we concluded that sap nitrate concentration is not a useful indicator of plant N status and yield response of Brussels sprouts.
Effect of variable carbonate concentration on the solidus of mantle peridotite

Abstract To explore the effect of variable CO2 concentrations on the solidus of natural carbonated peridotite, we determined near-solidus phase relations of three different nominally anhydrous, carbonated lherzolite bulk compositions at 6.6 GPa. Starting mixes (PERC, PERC2, and PERC3) were prepared by adding variable proportions of a carbonate mixture that has the same Ca:Mg:Fe:Na:K ratio as the base silicate peridotite [MixKLB-1: Mg no. = 89.7; Ca no. = molar Ca/(Ca + Mg + Fe*) = 0.05]. For all three bulk compositions, the subsolidus assemblage includes olivine, orthopyroxene, clinopyroxene, garnet, and magnesite solid solutions. Above the solidus, crystalline carbonate disappears and quenched Fe, Na-bearing dolomitic carbonatite melts were observed. For PERC3 (1.0 wt% bulk CO2; Na2O/CO2 weight ratio = 0.30), the observed solidus is between 1190 and 1220 °C; for PERC (2.5 wt% bulk CO2; Na2O/CO2 = 0.12), it is between 1250 and 1275 °C; and for PERC2 (5.0 wt% bulk CO2; Na2O/CO2 = 0.06), it is between 1300 and 1330 °C. At 6.6 GPa, experimental solidi of natural magnesite peridotites are 100.200 °C lower than the CMAS-CO2 solidus, chiefly owing to the fluxing effect of alkalis, and solidus temperatures increase with increasing bulk CO2 (i.e., decreasing bulk Na2O/CO2), owing to dilution of Na2O in near-solidus melt. The effects of Mg no. and Ca no. on carbonated peridotite solidi appear to be less significant than that of Na2O/CO2. Trends of decreasing solidus temperature with increasing Na2O/CO2 and with decreasing CO2 indicate that natural mantle peridotite with ~100.1000 ppm bulk CO2 will have solidus temperatures ~20° to ~100° lower than that determined experimentally. The solidus of peridotite drops discontinuously by ~600 °C (at 6.6 GPa) at the CO2 bulk concentration (~5 ppm) at which carbonate is stabilized, but then varies little with increasing bulk CO2. This result contrasts with the effect of H2O, which lowers the solidus continuously with increasing concentration.
Well-defined poly(N-isopropylacrylamide) with a bifunctional end-group: synthesis, characterization, and thermoresponsive properties

In this study, well-defined poly(N-isopropylacrylamide) (PNIPAM) with a bisalkyne end-group was synthesized by reversible addition-fragmentation chain transfer polymerization using 2-(2-(ethylthiocarbonothioylthio)-2-methylpropanoyl-oxy)ethyl 3,5-bis(prop-2-ynyloxy) benzoate (EMEB) as the chain transfer agent. The molecular weight and polydispersity index of polymer was determined by gel permeation chromatography (GPC). The linear increase in molecular weight with conversion, unimodal, and almost symmetrical peak in GPC trace together with low polydispersity indicated the controlled polymerization process of NIPAM mediated by EMEB. Subsequently, the Cu(I)-catalyzed [3 + 2] Huisgen cycloaddition between the end-group of polymer and azide derivatives was carried out to produce PNIPAM, in which the bisfunctional end-group was modified with phenyl, octyl, amido, and hydroxyl groups. After completing the click reaction, the structure of the polymer was characterized carefully by Fourier transform infrared spectroscopy (FTIR), 1H NMR, and Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS), indicating the complete consumption of alkyne end-groups. In addition, almost no change in molecular weight as well as the polydispersity was observed by comparison with the GPC traces of polymers before and after click reaction. The cloud point temperatures (T cps) of the resulting PNIPAM derivatives in aqueous solution were investigated in detail by dynamic light scattering. The results showed that the values of T cp were ranged from 22 to 38 °C, which depended largely on end-groups as well as the polymer molecular weights.
CORE PERSPECTIVES OF PERFORMANCE MEASUREMENT IN NPOS: IN SEARCH OF ACCOUNTABILITY AND LEGITIMACY

Purpose: The Main Purpose of this research is to set the scene for Non-Profit Organizations’ performance by synthesizing the vast array of literature on performance measurement frameworks to examine what constitutes performance measurement, and why it is a fundemental issue for the NPO sector. The research also analyses the main issues of performance measurement in NPOs. Methodology: This research takes the form of a literature review. The author draws on extensive research on measuring the performance in NPOs from a diverse range of disciplines to explore definitions, challenges and solutions with performance measurement in NPOs. Value: The categorizations of approaches to measure the performance in NPOs should guide researchers and practitioners. Findings: Non-Profit Organizations need new indicators to assess their economic, social and financial performance, in order to increase the accounting disclosure for social and economic value added resulting from its activities.
Reversible Migration of Lithium in Montmorillonites

The migration of lithium cations into the lattice of dioctahedral clays upon heating, considered up to now as irreversible, has been investigated. The samples examination are two lithium-saturated montmorillonites, selected with different charge-deficit distributions between the tetrahedral and octahedral sheets, to obtain direct information on the structural changes occurring in both layers. Reexpansion of these samples previously collapsed at 300[degree]C has been attained, for the first time, under high vapor water pressures. A structural characterization of the smectities under the different treatments has been monitored by means of X-ray diffraction, XRD, Fourier transform infrared spectroscopy, FTIR, and [sup 29]Si, [sup 27]Al, and [sup 7]Li magic angle spinning nuclear magnetic resonance, MAS-NMR. The effect that Li[sup +] ions exert on the quadrupolar coupling constant of tetrahedral Al ions has been shown. Direct experimental evidence on the location of lithium ions in the hexagonal holes of the collapsed structure is provided. Additionally, generation of protons during the rehydration process is concluded. 35 refs., 7 figs.
Herpesvirus Involvement in Lymphoma/Leukaemia and Related Disease

Human herpesvirus-6 (HHV-6) was first isolated from the peripheral blood of six individuals with lymphoproliferative or immunosuppressive disorders. Further studies identified HHV-6 DNA sequences in tumour biopsy samples from persons with lymphoma. Thus, initial findings suggested a link between HHV-6 and lymphoproliferative disease. This study was designed to examine further the association of HHV-6 with lymphomas and leukaemias by seroepidemiological investigations. Higher antibody titres to HHV-6 were identified in acute myeloid leukaemia, low-grade non-Hodgkin's lymphoma, and Hodgkin's disease (HD). Epidemiological evidence has lead to the proposition that HD, particularly in young adults, may have a viral aetiology and Epstein-Barr virus (EBV) has consistently been associated with this malignancy. Further analysis of both HHV-6 and EBV serology was carried out and the results suggested that the associations of both viruses with HD were relatively independent of each other. Thus, HD may be the result of an abnormal response to virus infection including EBV and HHV-6. To date there is little molecular evidence linking HHV-6 to HD, although recent studies have clearly demonstrated the presence of EBV within the tumour cells of the disease. In 1990, a human herpesvirus, distinct from those previously recognised, was isolated and named human herpesvirus-7 (HHV-7). The seroepidemiology of this virus in children and adults is presented in this dissertation. Infection with HHV-7 is widespread and infection occurs usually early in life. A likely vehicle for transmission is saliva. Herpesviruses have not only been associated with malignancy, but also chronic disease such as autoimmune conditions. EBV involvement has been proposed in the autoimmune disease, Sjogren's syndrome (SS). More recently HHV-6 has been linked to this condition. Viruses present within the epithelium of the salivary gland may play a role in the inflammation of such glands which is characteristically found in SS. This project studied possible viral involvement in SS by utilising the in vitro tissue culture of epithelial cells derived from salivary gland biopsies. The model proved useful as a means to study cytokine- mediated mechanisms of autoimmunity in particular the role of interferon-? and in the identification of putative retroviral antigens in salivary tissue.
Thermogravimetric Analysis of Biomass Pyrolysis under Different Atmospheres

Thermogravimetric analysis (TGA) was employed to study the effects of two different atmospheres (nitrogen and mixed biomass gasification gas) on the pyrolysis of rice husk, corn stalk and pine wood. Kinetic parameters were calculated based on the experiment data. The results indicated that TG and DTG curves moved to higher temperature range and the characteristic temperatures ascended as the increasing of the heating rate. Moreover, the three biomass materials exhibited similar pyrolysis behaviors under the two different atmospheres, but the activation energy values of the pyrolysis under mixed biomass gasification gas were higher than those under nitrogen.
Comparative Study of Organophilic Clays to be Used in the Gas & Petrol Industry

Brasgel clay and Gray clay has been been subjected to modification through ion-exchange reaction by quaternary ammonium (cetyltrimethyl ammonium bromide, CTAB). The samples were studied by X-Ray Diffraction, Infrared Spectroscopy, Scanning Electron Microscopy (SEM) and the Foster’s Swelling test. The results indicated that the quaternary ammonium salts were intercalated between the layers of clay. The basal spacing of unmodified Brasgel clay, determined by XRD, was 1.329 nm and after modification it increased up to 2.101 nm. By analyzing the results obtained in this study, particularly those provided by infrared spectroscopy, it was concluded that the treated, organophilic sample (modified with CTAB) comprised CH2 and CH3 groups in its structure, which provides evidence of the efficiency of the organophilization process. Foster´s swelling was carried out with and without agitation in gasoline, diesel, toluene and lubricating oil. The results indicated the samples was organophilic materials, with improved efficiency of Brasgel clay in gasoline and diesel and when compared to Gray clay in the test of capacity for adsorption and Foster´s swelling, the results were similar to kerosene and lubricating oil.