Miracle-dz/UniFAR-FTUs huggingface dataset:
Electrostatic Mechanism of Nucleation and Growth of Metal Whiskers

abstract Metal whiskers can grow across leads of electric equipment causing short circuits, arcing, and raising significant reliability issues. The nature of metal whiskers remains a mystery after several decades of research. Here, their existence is attributed to the energy gain due to electrostatic polarization of metal filaments in the electric field induced by a metal surface. The field is induced by surface imperfections: contaminations, oxide states, grain boundaries, etc. This theory provides closed form expressions and quantitative estimates for the whisker nucleation and growth rates, explains whisker by V. G. Karpov DepArTMenT OF pHYSiCS AnD ASTrOnOMY, univerSiTY OF TOleDO Electrostatic Mechanism of Nucleation and Growth of Metal Whiskers
Evaluation of pumpkin-rowanberry marmalade quality after different drying times

Historically, marmalades may have originated as an early effort to preserve fruit for consumption in the off-season. Marmalades are basically products with fruit puree and sugar–acid–pectin gel. The aim of the current research was to determine the chemical and physical properties and to investigate the degree of acceptance of pumpkin – rowanberry marmalade. The experiments were carried out at the Faculty of Food Technology of the Latvia University of Agriculture. The marmalade was made from Cucurbita maxima pumpkin and sweet rowanberry Sorbus aucuparia cultivar ‘Nevezhinskaya’ pur e es. D ifferent drying times in oven at a temperature of 50 ± 2 °C were examined and compared with marmalade drying in air ambiance at room temperature. The moisture, total carotene, ascorbic acid content, hardness, colour, and the degree of acceptance of marmalade samples were determined as quality evaluation. The results of the research have shown a large variability in the physical and chemical parameters among the marmalades after different drying times. The moisture content of marmalade samples decreased by 9.1 to 33.5 %, and hardness increased from 1.85 to 9.54 N. According to sensory evaluation, consumers liked pumpkin–rowanberry marmalade samples after drying in the air ambiance at room temperature. DOI: http://dx.doi. org/10.5755/j01.ct. 62.4. 3412
Dielectric Dispersion in Materials Having a Distribution of Relaxation Times

On the basis of considerable experimental evidence, a particular form for the dielectric loss factor, e″, is assumed to hold for many materials exhibiting a distribution of relaxation times. The dielectric constant, e′, corresponding to the assumed form of e″ is then computed by means of the Kronig‐Kramers relations and tabulated as a function of log frequency and of the distribution function half‐width parameter, α. Using these results, experimental e′ and e″ curves can be easily tested for mutual consistency and can be fitted individually. In conclusion, a brief discussion of other methods of dealing with the many‐relaxation‐time dispersion problem is given.
Segmented polyurethane elastomers derived from aliphatic polycarbonate and poly(ester‐carbonate) soft segments for biomedical applications

A series of biomedical polyurethane elastomers (PURs) based on poly(ester-carbonate)s (PECs) and polycarbonates (PCs) were synthesized and spectrally characterized fully. PEC or PC diols were synthesized by the ring-opening polymerization of e-caprolactone, trimethylene carbonate, and neopentyl carbonate catalyzed by lipase from Candida antarctica. PURs were prepared by free-metal method from PEC or PC diols and 4,4′-methylenebis(phenyl isocyanate), with 1,4-butanediol as a chain extender. The physical and mechanical properties as well as hydrolytic stability of the obtained PURs were determined. The toxicity of the received polymers was evaluated using bacterial luminescence test and two protozoans assays. The presented preliminary studies suggest that PEC or PC diols prepared in this way might be applied for the synthesis of biomedical PURs with improved hydrolytic stability. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Inhibition of solution crystal growth of ritonavir by cellulose polymers – factors influencing polymer effectiveness

Inhibition of crystallization, either nucleation or crystal growth, from supersaturated solutions used to enhance the delivery of poorly water soluble drugs is an important area of study. The use of polymers as crystallization inhibitors may significantly impact the extent and duration of supersaturation and thus bioavailability. In this study, we investigate the principal factors influencing crystal growth inhibition of ritonavir by cellulose adipate polymers. Bulk crystal growth rates of ritonavir in the presence and absence of pre-dissolved polymer were estimated from seeded-desupersaturation experiments under different conditions of pH and supersaturation. It was found that the effectiveness of the cellulose adipate polymers decreased at low pH due to the pH-dependent ionization ratio of the adipate carboxyl group of these cellulose esters, which may influence the conformation and extent of coverage. The Kubota-Mullin model was used to predict the magnitude of growth inhibition. Above a critical supersaturation, the Kubota-Mullin model was quantitatively inaccurate, due to a change in growth mechanism from layer-face growth to fast continuous growth. The polymers were less effective at inhibiting crystal growth at the high supersaturation generated by the amorphous solid due to a fast continuous growth mechanism at high supersaturations.
Intensity-referenced and temperature-independent pressure sensing based on strain-chirped fiber Bragg grating

Temperature-insensitive pressure measurement using a single fiber Bragg grating (FBG) based on reflection spectrum bandwidth modulation and optical power detection is proposed. A specially designed double-hole cantilever beam (DHCB) is used to provide pressure induced axial strain gradient along the sensing FBG and further modulate the reflection bandwidth of the grating. The bandwidth modulation immunes to spatially uniform temperature effect and the pressure can be unambiguous determined by reflected optical power measurement, avoiding the complex wavelength interrogation system. The thermal fluctuate of the system is less than 1.2 % F.S. for temperature range from -10°C to 80 °C without any temperature compensation.
EFFECTS OF UNDER CNT METALLIZATION LAYERS ON CARBON NANOTUBES GROWTH

Carbon nanotubes (CNTs) were grown on a Ni catalyst layer with four different types of under-CNT-metallization layers, namely SiO2, Al, Cu and Cr, using hot filament chemical vapor deposition (HFCVD). The morphology and microstructure of the CNT films were analyzed by scanning electron microscopy (SEM) and Raman spectrometer. It was found that the level of interaction between the Ni catalyst layer and under-CNT-metallization layer has significant effects on carbon nanotubes growing characteristics. It was observed that carbon nanotubes grown on SiO2 under-CNT-metallization layer recorded the highest density and smallest diameter. When Cu or Cr under-CNT-metallization layers were employed, high density and larger diameter nanotubes were obtained. No carbon nanotubes were found on samples with Al under-CNT-metallization layer under similar growth conditions. These findings add significant reference values for selection under CNT metallization layers suitable for carbon nanotube interconnect applications.
Rates of Ionic Reactions in Aqueous Solutions

The effect of the addition of ``inert'' salts on ionic reaction rates is discussed. For reactions between ions of the same charge sign, the effect is caused almost exclusively by the concentration and character of salt ions of charge sign opposite to that of the reactants. The rate is not dependent upon the ionic strength of the solutions. In reactions between ions of opposite charge sign, both salt ions may affect the rate, but the effect of one type may be dominant. The effects are quantitatively interpretable in terms of an ion association constant and specific rate constants for the associated and non‐associated reactants. The further introduction of activity coefficients is not necessary. The reactions upon which the Livingston Diagram is based have been explored from this viewpoint and found to be in quantitative accord.
Oxide melt solution calorimetry of Fe2+-bearing oxides and application to the magnetite–maghemite (Fe3O4–Fe8/3O4) system

Abstract A consistent methodology for obtaining the enthalpy of formation of Fe2+-containing binary and multicomponent oxides using high-temperature oxide melt solution calorimetry has been developed. The enthalpies of wüstite (FeO) and magnetite (Fe3O4) oxidation to hematite (Fe2O3) were measured using oxidative drop solution calorimetry in which the final product is dissolved ferric oxide. Two methods were applied: drop solution calorimetry at 1073 K in lead borate solvent and at 973 K in sodium molybdate, each under both oxygen flowing over and bubbling through the solvent, giving consistent results in agreement with literature values. The enthalpies of formation of all three iron oxides from the elements were obtained using a thermodynamic cycle involving the directly measured oxidative dissolution enthalpy of iron metal in sodium molybdate at 973 K and gave excellent consistency with literature data. The methodology was then applied to the magnetite-maghemite system. The enthalpy of mixing of the Fe3O4-Fe8/3O4 spinel solid solution is exothermic and, represented by a subregular (Margules) formalism, ΔHmix = x(1 - x)[-63.36 ± 8.60(1 - x) + 17.65 ± 6.40x] kJ/mol, where x is the mole fraction of magnetite. The entropies of mixing of the solid solution were calculated for different assumptions about the distribution of cations, charges, and vacancies in these defect spinels. The different models lead to only small differences in the entropy of mixing. Calculated free energies of mixing show no evidence for a solvus in the magnetite-maghemite system.
Thermal-runaway experiments on consumer Li-ion batteries with metal-oxide and olivin-type cathodes

Li-ion batteries play an ever-increasing role in our daily life. Therefore, it is important to understand the potential risks involved with these devices. In this work we demonstrate the thermal runaway characteristics of three types of commercially available Li-ion batteries with the format 18650. The Li-ion batteries were deliberately driven into thermal runaway by overheating under controlled conditions. Cell temperatures up to 850 °C and a gas release of up to 0.27 mol were measured. The main gas components were quantified with gas-chromatography. The safety of Li-ion batteries is determined by their composition, size, energy content, design and quality. This work investigated the influence of different cathode-material chemistry on the safety of commercial graphite-based 18650 cells. The active cathode materials of the three tested cell types were (a) LiFePO4, (b) Li(Ni0.45Mn0.45Co0.10)O2 and (c) a blend of LiCoO2 and Li(Ni0.50Mn0.25Co0.25)O2.
Construction of Cu(II), Zn(II) and Cd(II) metal–organic frameworks of bis(1,2,4-triazol-4-yl)ethane and benzenetricarboxylate: syntheses, structures and photocatalytic properties

Three coordination polymers {[Cu4(OH)2(btre)(1,2,3-btc)2(H2O)2]·2H2O}n (1), {[Zn4(OH)2(btre)(1,2,3-btc)2(H2O)4]·4H2O}n (2) and {[Cd3(btre)(1,2,3-btc)2(H2O)3]·3H2O}n (3) were synthesized by the hydrothermal method using 1,2-bis(1,2,4-triazol-4-yl)ethane (btre), 1,2,3-benzenetricarboxylate (1,2,3-btc) and metal ions (Cu(II), Zn(II), and Cd(II)). 1 shows a (3,8)-connected 3D metal–organic framework based on the tetranuclear copper(II) cluster [Cu4(μ3-OH)2] with the point symbol of (4·52)3(44·55·612·73·83·9). 2 exhibits a (3,8)-connected 3D metal–organic framework based on the tetranuclear zinc(II) cluster [Zn4(μ3-OH)2] with the point symbol of (42·6)3(46·618·83·10). In 3, each [Cd3(1,2,3-btc)2(H2O)]n chain connects four adjacent identical [Cd3(1,2,3-btc)2(H2O)]n chains through the btre bridges in four different directions, leading to an unusual 3D network. 3 shows a 4-connected 66dia topological net based on the [Cd3(H2O)(COO)4] trimer Cd(II) clusters. The diverse structures demonstrate that the central metal ions play the key role in the assembly of coordination polymers. 1 and 2 show good photocatalytic activity for the degradation of methyl orange. The luminescence of 2 and 3 was investigated.
New Ammonium- and 1,2,4-Triazolium-Based Ionic Liquids for Wood Preservation

Biological activity of new potential wood preservatives—ammonium- and triazolium-based ionic liquids—was determined employing screening agar-plate, agar-block, and perlite-block methods. Experiments were carried out on Scots pine (Pinus sylvestris L.) and beech (Fagus sylvatica L.) wood. This study examined the effect of the ionic liquid structure on anti-fungal efficacy, depth of penetration, and fixation in wood. It was stated that the fungicidal value of new ammonium compounds depended, above all, upon the cation structure; for Coniophora puteana, it ranged from 2.7 kg m−3 to 4.6 kg m−3. These compounds effectively protected Scots pine wood against the action of mold fungi. Ammonium ionic liquids with a nitrite anion were characterized by strong fungitoxic properties, stronger than ammonium nitrates. The application in the amount of 15 g m−2 caused an insignificant growth of mold fungi on the surface of Scots pine wood. For the mixture of 7.5% tebuconazole and 7.5% propiconazole dissolved in ionic liquids, the synergistic effect against mold fungi at the application of 15 g m−2 was found. Dissolving tebuconazole in didecyldimethylammonium nitrate repeatedly lowered the fungicidal value against brown-rot fungi, as well as increased penetration of the ionic liquids in wood. This was associated with reduced viscosity of this ionic liquid caused by the addition of 1,2,4-triazole derivatives. Quaternary derivatives of 1,2,4-triazoles showed very high activity against blue stain and wood-decaying fungi. Additionally, most of the test compounds were well-fixed in Scots pine wood. The spectral study in infrared confirmed that nitrite, nitrate anions, and didecyldimethylammonium cation were retained in the treated wood.
Mechanical properties of sugar beet roots during harvest and storage.

Comparative study of root mechanical properties of four sugar beet cultivars over harvest and storage periods in the conditions of static loads were carried out including determination of some mechanical parameters of beet root skin in two measurement zones within the applicability range of the Hook's law. Tests concerning the effect of cultivar and measurement zone on tested parameters were performed on a micro tensile tester, Zwick model 1425 in the Department of Agricultural Production Technology. The average values of skin destruction forces were 241.22 - 254.1 N and 227.4 - 245.8 N for freshly harvested sugar beet roots and after 45 days of storage,
Improvement of the quality and shelf life of concentrated yoghurt (labneh) by the addition of some essential oils

Three essential oils, namely thyme, marjoram and sage, were added to concentrated yoghurt (labneh) at concentrations of 0.2, 0.5 and 1.0 parts per million (ppm). Subsequently, the chemical, microbiological and organoleptic properties of freshly prepared labneh and of the labneh stored at 5˚C ± 1 for up to 21 days were determined. Addition of essential oils affected the pH, soluble nitrogen-to-total nitrogen, total volatile fatty acid and acetaldehyde values of the prepared labneh. On the other hand, total solids and fat-to-dry matter values were only slightly affected. Total viable counts, as well as counts of Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus in the treated labneh increased and reached a maximum after 7 days of storage where after it decreased until the end of the storage period. Yeasts and moulds, coliform bacteria and spore-forming bacteria were not detected in the treated labneh. Of the different treated labneh, labneh containing 0.2 ppm thyme, marjoram or sage oils were organoleptically the most acceptable, and it had a good body and texture that was similar to that of the untreated control. From the results of this study, it can be concluded that 0.2 ppm of thyme, marjoram or sage can be used in order to increase the shelf life of labneh for up to 21days.
Effect of Molecular Weight and Annealing of Poly(3‐hexylthiophene)s on the Performance of Organic Field‐Effect Transistors

The optical, structural, and electrical properties of thin layers made from poly(3‐hexylthiophene) (P3HT) samples of different molecular weights are presented. As reported in a previous paper by Kline et al., Adv. Mater. 2003, 15, 1519, the mobilities of these layers are a strong function of the molecular weight, with the largest mobility found for the largest molecular weight. Atomic force microscopy studies reveal a complex polycrystalline morphology which changes considerably upon annealing. X‐ray studies show the occurrence of a layered phase for all P3HT fractions, especially after annealing at 150 °C. However, there is no clear correlation between the differences in the transport properties and the data from structural investigations. In order to reveal the processes limiting the mobility in these layers, the transistor properties were investigated as a function of temperature. The mobility decreases continuously with increasing temperatures; with the same trend pronounced thermochromic effects of the P3HT films occur. Apparently, the polymer chains adopt a more twisted, disordered conformation at higher temperatures, leading to interchain transport barriers. We conclude that the backbone conformation of the majority of the bulk material rather than the crystallinity of the layer is the most crucial parameter controlling the charge transport in these P3HT layers. This interpretation is supported by the significant blue‐shift of the solid‐state absorption spectra with decreasing molecular weight, which is indicative of a larger distortion of the P3HT backbone in the low‐molecular weight P3HT layers.
TALL FESCUE GROWTH IN GREENHOUSE, GROWTH CHAMBER, AND FIELD PLOTS AMENDED WITH SEWAGE SLUDGE COMPOST AND FERTILIZER

Recommendations for using sewage sludge compost to satisfy the N requirement of crops, which resulted from greenhouse and controlled environmental growth chamber studies, have not been sufficiently validated with field trials. Studies were conducted to evaluate the effects of sewage sludge compost and complete fertilizer amendments on yields and N content of ‘Kentucky 31’ tall fescue (Festuca arundinacea Schreb.) grown on Evesboro loamy sand (mesic, coated Typic Quartzipsamments) in different environments. Compost was applied at rates of either 0, 45, 90, or 135 Mg ha-1 in greenhouse and growth chamber pot studies and 0, 60, 120, and 240 Mg ha-1 in field trials. Fertilizer (N,P,K) was applied at 0 and 200 kg ha-1 where indicated. Compost amendment increased the yields of fescue linearly in all three growth environments. For the second crop, yields were 50% of those for the first crop in the growth chamber and 60% of those for the first crop in the field. A conservative estimate for compost N utilization by the fescue crop was 8% for the initial cropping season and 5% for the second season (determined from the entire plant uptake in the greenhouse and growth chamber). These estimates may be low because the average utilization of compost N by the tall fescue in the field plots was 7% for the first year clippings alone (roots and stubble not analyzed). Equivalent dry matter yields were obtained for the 135 Mg ha-1 compost amendment and complete fertilizer for greenhouse grown fescue; however, equivalent yields for the field-grown fescue were realized by the 60 Mg ha-1 compost amendment. Model equations were derived for estimating fescue yield from compost-amended soil.
ESR observation of the microstructure of polymer carbon-black composites. Correlation with dielectric properties

We describe the results of an experimental study of the dielectric and physicochemical properties of a composite material prepared by incorporating carbon black particles into a polymer matrix. The analysis of the carbon black concentration dependence of the amplitudes and linewidths of the ESR signals indicates that ESR is an important experimental probe of the structure of the elasticity network. Sorption kinetics experiments with toluene indicate that the uptake of solvent exhibits a square root dependence in time as a consequence of Fick's law and permit one to evaluate the effective diffusion coefficient in the range 10/sup -10/-10/sup -11/ cm/sup 2/ s/sup -1/ depending on the mass fraction of the carbon black in the sample.
Diverging Geometric and Magnetic Size Distributions of Iron Oxide Nanocrystals

An important reason to prepare magnetic nanoparticles of uniform size and shape is to ensure uniform magnetic properties. However, here, we demonstrate that magnetic iron oxide crystals of 20 nm or less with a low polydispersity of the geometric size can nevertheless have a strikingly broad distribution of the magnetic dipole moment. A comparative study was performed on nanoparticles with near-perfect crystallinity, twinning defects, or a high density of dislocations. Size, shape, and crystal defects were characterized with electron microscopy and X-ray diffraction, and magnetic dipole moments were determined from magnetization curves of dilute colloidal dispersions. The largest divergence was found for spherical particles with 3.5% geometric size polydispersity and 35% magnetic size polydispersity due to crystal lattice defects that disrupt single-domain magnetic spin coupling. This is in stark contrast with the usual implicit assumption that uniform size and shape guarantee well-defined magnetic propert.
Über Verbindungen mit Urotropin-Struktur, XVI. Beiträge zur Chemie der Adamantyl-(1)-Derivate

Fur die Bromierung des Adamantans wird ein Ionenmechanismus wahrscheinlich gemacht. Die Kinetik der Solvolyse des 1-Brom-adamantans wurde ermittelt. 1-Amino-adamantan konnte durch die Ritter-Reaktion von 1-Brom-adamantan mit Acetonitril und die alkalische Verseifung des so gewonnenen 1-Acetamino-adamantans erhalten werden. Auf einem zweiten Wege wurde die Base durch Hofmann-Abbau von Adamantan-carbonsaure-(1)-amid hergestellt. Es werden Reaktionen des Amins und seiner Derivate beschrieben.
Cinética da degradação de geleiada de morango

Strawberry jelly was stored at 20 (control), 30 (room) and 40 (accelerated) oC in order to evaluate their shelf lives. The shelf-life evaluation was based on objective color readings of L a b Hunter color (Minolta Chroma Meter CR-400) and on subjective color methods, smell, flavor, and texture (Quantitative Descriptive Analysis) measurements. Objective and subjective analyses were carried out for 180 days at 30-day intervals under three different conditions. Experimental data show that the color degradation followed the model of a first order kinetic reaction. The Arrhenius model was applied to the reaction rates (k) at each temperature obtaining activation energy (Ea) of 5.66 kcal.mol-1 and a Q10 of 1.36. The jellies showed adequate quality with relation to acid ascorbic content in the occasion of the processing, but they had presented low vitamin C retention. On the 60th day, the vitamin C content reduced more than 98%, regardless of the storage condition. The jellies stored at 40 oC proved more sensitive to the alterations in the color, and such temperature affected negatively the sensory attributes indicated by the browning and losses of smell, flavor, and texture. The results suggest that strawberry jellies must be stored under controlled conditions of temperature (20 to 30 oC).