Miracle-dz/UniFAR-FTUs huggingface dataset:
Factors influencing the critical product in electromigration

Als Elektromigration bezeichnet man den durch einen elektrischen Strom induzierten Materialtransport, der durch die Bildung von Poren und Hugeln zum Ausfall von elektrischen Leiterbahnen in integrierten Schaltkreisen fuhren kann. Es hat sich herausgestellt, das die Schadigung durch Elektromigration unterdruckt werden kann, wenn das Produkt aus Stromdichte und Leiterbahnlange einen bestimmten Wert nicht uberschreitet. Dieser Effekt wurde dem Aufbau eines mechanischen Spannungsgradienten zugeschrieben, der dem elektromigrations-induzierten Materialtransport solange entgegenwirken kann, bis eine bestimmte kritischen Spannung erreicht wird, ab der sich das Material plastisch verformt. In dieser Arbeit wurde die kritische Spannung mit der Fliesspannung der Schicht verglichen, die mit Hilfe der Substratkrummungsmethode bestimmt wurde. Hierbei hat sich gezeigt, das es signifikante Unterschiede zwischen diesen beiden Spannungen gibt, die darauf zuruckgefuhrt wurden, das die Fliesspannung einen Mittelwert uber eine grose Anzahl von Kornern reprasentiert, wahrend die kritische Spannung mit der Deformation von nicht-(111) Kornern verknupft ist, die nur einen geringen Bruchteil der gesamten Schicht ausmachen. Weitere Untersuchungen haben gezeigt, das die Bildung von Hugeln bevorzugt in nicht-(111) Kornern durch den Materialeinbau in die Schicht/Substrat Grenzflache erfolgt und gewohnlich mit Kornwachstum verbunden ist. Schlieslich wurde ein Modell fur elektromigrationsinduziertes Hugelwachstum vorgeschlagen, das die Existenz einer kritischen Spannung erklaren kann. Electromigration is the electric current-induced transport of atoms, which can cause failure in the small interconnect lines of intergrated circuits through the formation of voids and hillocks. It has been found that the formation of electromigration-induced damage is suppressed if the product of current density and interconnect length is smaller than a certain critical value. This effect has been attributed to the generation of mechanical stress gradients which balance the electromigration force until a certain 'threshold stress' is reached and the material begins to deform plastically. However, an in-depth understanding of the atomic mechanisms that lead to a threshold stress for deformation has not yet been achieved. In this work the electromigration threshold stress was compared with the flow stress of the films, as determined by wafer curvature. It was found that there are significant differences between these two stresses which are attributed to the fact that the flow stress of the film represents an average over a large number of grains while the electromigration threshold stress is associated with deformation of non-(111) grains which make up only a small fraction of the film. Further investigations have shown that hillocks grow preferentially in non-(111) grains by the addition of material at the bottom of the grain which is often accompanied by grain growth. Finally, a model is proposed for electromigration-induced hillock growth which may account for the measured threshold stress.
Synthesis of Glycoconjugated Phthalonitriles for New Phthalocyanine-Based Photosensitizers

GRAPHICAL ABSTRACT Excellent photophysical and photochemical properties completed by magnificent take-up rates in malignant tissues attracted a great deal of interest to the application of glycosylated and glycoconjugated phthalocyanines in photodynamic therapy. In this study we describe the concise synthesis and full characterization of 16 differently 3,6-bisglycoconjugated phthalonitriles 3, 5, 6, 8, and 48–59, which are precursors for a new generation of photosensitizers, namely, nonperipheral glycoconjugated phthalocyanines. The first example for the synthesis of a nonperipheral glycoconjugated zinc phthalocyanine 60 from phthalonitrile 48 is also presented in this work.
Adsorption of copper(II) and chromium(III) ions onto amidoximated cellulose

Chemical modification of cellulose powder is performed by successive reactions with acrylonitrile in an alkaline medium followed by aqueous hydroxylamine to prepare amidoximated cellulose. Due to complexation, the amidoxime groups immobilize heavy cations from buffered solutions at various pH values. The capacity of adsorption for Cu(II) and Cr(III) ions is related to the amount of amidoxime groups in the support and to the metal concentration of the polluted solution. The formation of a 1/1 complex is proved by the adsorption limit values. Desorption of the cations is possible by treatment with a stronger complexing agent such as ethylenediaminetetracetic acid.
Geometrical optimization and contact configuration in radial pn junction silicon nanorod and microrod solar cells

Electric charge transport simulations of symmetrically doped radial pn junction silicon nanorod solar cells were performed using the Technology Computer‐aided Design software suite by Silvaco. Two schemes of electric contacting were applied, the first one consisting of a cathode wrapped around the cladding of the rod and the second one in a cathode located only on the top rod surface. In both cases, the anode was implemented just below the bottom end of the p‐type rod core. P‐type cores and n‐type shells of the rods were assumed, with dopant densities of 1018 cm− 3 in both regions. The location of the pn junction was chosen such that well‐formed space charge regions could be established with the outer end of the n‐type depletion region being adjacent to the cylindric surface of the nanorod. Rod radii and rod lengths were varied and optimized in a three‐step process for both types of contacting schemes. It was found that inhomogeneous carrier generation profiles diminish the open‐circuit voltage in case of a wrapped cathode configuration. Most realistic is the usage of a top contact configuration with rod radii of 2 µm and lengths of around 100 µm, leading to a cell efficiency of about 15%. Further enhancement of performance is expected, if light trapping of the nanorod layer is taken into account and photonic light harvesting is applied. Copyright © 2012 John Wiley & Sons, Ltd.
Controlled synthesis of Pd and Pd–Au nanoparticles: effect of organic amine and silanol groups on morphology and polycrystallinity of nanomaterials

The synthesis of palladium (PdNPs) and its bimetallic (Pd–Au/Au–Pd) nanoparticles of controlled nanogeometry, polycrystallinity and functional ability is a challenging task. We report a new process for metal nanoparticles synthesis meeting these requirements that incorporate the specific role of organic amine and silanol functionalities with the following major findings: (1) the concentrations of organic amine control the nanogeometry and functional ability of the nanoparticles; (2) the polycrystallinity of PdNPs tends to decrease as a function of silanol concentration justifying specific interaction of PdNPs and silanol groups whereas AuNPs do not show such interaction; (3) transition in microstructure from hexagonal nanogeometry to circular nanogeometry of palladium nanoparticles (PdNPs) in the presence of a silanol group; (4) initial reduction of palladium ions followed by reduction of gold ions during the synthesis of bimetallic nanoparticles results in negligible interaction of the silanol residue and PdNPs justifying an increase in polycrystallinity whereas simultaneous reduction of the same enable a decrease in polycrystallinity; (5) initial reduction of gold ions causes aggregation of the same forming larger nanoparticles and reveals negligible interaction with silanol content under similar conditions; (6) the size of nanoparticles decreases with an increase in silanol concentration as a function of nanoparticle–silanol interaction. As synthesized PdNPs shows peroxidase mimetic activity as a function of 3-APTMS concentration.
Hyperbranched cyclic and multicyclic poly(etherketone)s by polycondensation of isosorbide and isomannide with 2,6,4′-trifluorobenzophenone and 1,3,5-tris(4-fluorobenzoyl) benzene

1,3,5-Tris(4-fluorobenzoyl)benzene (TFBB) and 2,6,4′-trifluorobenzophenone (TFB) were polycondensed with isosorbide and isomanide. All polycondensations were performed in a mixture of dimethyl sulfoxide and toluene with potassium carbonate as promotor. Optimal concentration to avoid gelation was set at 0.06 mol L−1. The different cyclization tendencies on the basis of monomers conformations are discussed. In the TFB series, the feed ratio isosorbide/TFB was varied from 1.0:1.0 to 1.5:1.0. A majority of linear and hyperbranched species were identified as main reaction products by matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry regardless of the diol with slight cyclization tendency for isomannide. When TFBB was polycondensed with isosorbide, the cyclization tendency was significantly improved. The products obtained at a feed ratio of 1.41/1.0 and 1.51/1.0 were rich in cyclic and multicyclic species. More interesting results were obtained from the polycondensation of TFBB and isomannide, giving rise majoritarily to cyclic, bicyclic, and multicyclic species. Differential scanning calorimetric measurements indicated high glass transition temperature (around 200°C).
Study of bio-aerosols in a prominent temple in Mumbai City, India

Numerous health complaints occur with respect to indoor air quality and scanty information is available on the air flora, particularly with respect to bio-aerosols in India. This paper reports a study which examined air quality in a prominent temple in the city of Mumbai. It was found that the indoor microbial load was significantly higher probably because appropriate ventilation systems were lacking. In the festive month of September, the highest bacterial counts (13.98 × 104 CFU/m3) and fungal counts (9.22 × 104 CFU/m3) were observed. Pseudomonas spp. and Aspergillus spp. were found to be predominant in the air microflora sampled. Correlation analysis with meteorological factors such as temperature, relative humidity and wind speed showed that these were non-significant. The study indicated that poor ventilation, number of occupants and their activities in a given area are largely responsible for the variation in microbial loads observed. The data generated underline the question of monitoring crowded areas including places of religious importance. Some remedial measures are suggested.
Incident shock-wave characteristics in air, argon, carbon dioxide, and helium in a shock tube with unheated helium driver

Incident shock-wave velocities were measured in the Langley 6-inch expansion tube, operated as a shock tube, with air, argon, carbon dioxide, and helium as test gases. Unheated helium was used as the driver gas and most data were obtained at pressures of approximately 34 and 54 MN/sq m. A range of pressure ratio across the diaphragm was obtained by varying the quiescent test-gas pressure, for a given driver pressure, from 0.0276 to 34.5 kN/sq m. Single- and double-diaphragm modes of operation were employed and diaphragms of various materials tested. Shock velocity was determined from microwave interferometer measurements, response of pressure transducers positioned along interferometer measurements, response of pressure transducers positioned along the driven section (time-of-arrival gages), and to a lesser extent, measured tube-wall pressure. Velocities obtained from these methods are compared and limitations of the methods discussed. The present results are compared with theory and the effects of diaphragm mode (single or double diaphragm), diaphragm material, heating of the driver gas upon pressurization of the driver section, diaphragm opening time, interface mixing, and two-dimensional (nonplanar) flow are discussed.
Utilização do nitrogênio da palha de milho e de adubos verdes pela cultura do milho

The quality of commercial crop residues and green manure influences the N mineralization-immobilization rate and the respective use by subsequent crops. With the objective of evaluating N utilization by corn of N from the shoot and root system of sunnhemp (Crotolaria juncea) and millet (Pennicetum americanum) and corn straw, labeled with 15N, a green house experiment was carried out at the Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, S. Paulo, Brazil, in 5 kg pots with dystroferric Red Latosol in a completely randomized design, with four replications and the following six treatments: T1 = 15N labeled corn straw (above ground part, except grains) (80 mg kg-1 N in soil); T2 = 15N labeled millet root (30 mg kg-1 in soil); T3 = 15N labeled millet shoot (80 mg kg-1 N in soil); T4 = 15N labeled sunnhemp root (30 mg kg-1 N in soil); T5 = 15N labeled sunnhemp shoot (80 mg kg-1 N in soil) and T6 = treatment without addition of organic N source. In the treatments with 15N labeled root application, unlabeled shoot at the same amount added as in those where labeled shoot was applied, and vice-versa. The roots were incorporated into the soil and shoots left on the surface. To evaluate N absorption from 15N corn straw (7.35 Mg ha-1, equivalent to 56 kg ha-1 N) by corn crop, a field experiment was carried out, in the same area where the soil for the green house experiment had been collected. The amount of corn N derived from sunnhemp (111.80 mg pot-1 N) was higher than from millet (30.98 mg pot-1 N), which in turn higher was than from corn plant residues (11.80 mg pot-1 N). Sunnhemp resulted in highest nitrogen absorption and dry matter weight of the corn crop. The corn utilized more N from sunnhemp shoot than from roots, but there was no difference in N derived from millet. The N absorption of corn from corn straw was 4.1 % of the initial amount in the field experiment.
Optimized time-of-flight secondary ion mass spectroscopy depth profiling with a dual beam technique

High resolution depth profiling has been performed in a time-of-flight secondary ion mass spectroscopy (TOF-SIMS) instrument equipped with independent ion sources for sputtering (crater formation) and for SIMS analysis. In this dual beam mode a low energy sputter gun (Cs or any gas ion) allows a free selection of optimum sputter conditions with regard to depth resolution and matrix optimization. For secondary ion generation an independent high energy ion beam, optimized with regard to focussing and secondary ion yield (Ga or gas ion source) is applied. For different sputter gases (Ar, Xe, O2, and SF6), energies (0.3–2 keV) and angles of incidence a systematic investigation of B layers in Si and GaAlAs multilayers has been carried out. Decay lengths of 0.53 nm were achieved for low energy sputtering of B layers in Si with 0.6 keV SF5+. In this dual beam mode the depth profiling performance of TOF-SIMS exceeds that of state of the art quadrupole and magnetic sector field instruments in several fields of app.
Humidified Gas Stream Separations at High Temperatures Using Matrimid 5218

Most industrially relevant high temperature gas separations (≥150°C) of either carbon dioxide (flue gas) or hydrogen (syn-gas) must be performed in the presence of water vapor. At ambient temperatures, water vapor can permeate easily through most polymeric membranes and can influence the permeation of other gases through interaction with the polymer, such as swelling and clustering. At higher temperatures, water vapor can be destructive to polymer membranes by changing the polymer structure that can result in diminished gas separation performance. Little data has been reported on the influence of water vapor in gas separations at >100°C because most polymers are not stable at temperature. Many high performance (HP) polymers are able to endure high temperatures and aggressive chemical conditions. For example, polyimides are promising HP polymers that effectively separate permanent gases at temperatures higher than 150°C under dry conditions. In this report, the analysis of selected HP polymers in humidified gas streams (2–4 vol% water) shows that they can perform modest separations at ambient temperatures. In general, it was observed that water vapor permeability is greater than other tested gases. Additionally, the permeabilities of the analyte gases were somewhat influenced by the presence of humidity and their selectivities were significantly lower, as compared to corresponding experiments performed in the absence of water. To elucidate the role of water vapor in gas transport, energy of activation of permeation (Ep) values were obtained for Matrimid 5218 from 30–200°C in a humidified mixed gas stream, and it was found that the selectivities are nearly identical to dry gas streams at 150°C. This data suggests that water vapor functions as a gas and only slightly decreases selectivity of the other gases at elevated temperatures. As a result, economic wet gas separations may be possible using these materials if the gas stream is kept at higher temperature (≥150°C), which is assisted by the inherent stability of the membranes.
Evaluation of Some Impregnating Agents for Use in Paper Conservation

Five commercially available materials were tested as impregnating agents for paper. They were Elvanol 5105, Kelgin LV, Klucel G, Methocel A15C and Viscarin GP209. Whatman no. 1 chromatography was used as support and solutions o.1% and 1% w/v used. Dry oven ageing was at 100 C. For upto 14 days. At the lower concentration none of the solutions increased paper strength, at 1% Kelgin, Methocel and Viscarin only. After ageing Methocel was best, Viscarin the worst (for folding endurance). Colour changes, ph changes were small for all materials. All the materials were completely soluble in water, partially soluble in toluene, after 16 hours at 120 C. Tables, references.
Quality changes in sardines (Sardina pilchardus) stored in ice and at ambient temperature

Abstract The keeping times of sardines were 21–27 h (average 23 h) at ambient temperature ( T amb ) and 8–11 days (average 9.5 days) in ice. The muscle pH increased from 6.15 to 6.85 at T amb and from 6.24 to 6.55 in ice. Trimethylamine–nitrogen (TMA-N) and total volatile basic nitrogen (TVB-N) accumulated rapidly at T amb to reach 11.2 mg 100 g −1 of fish and 57.3 mg 100 g −1 of fish, respectively at spoilage. In ice, the rate was rapid for two trials (2.72 mg TMA-N 100 g −1 of fish per day and 5.20 mg TVB-N 100 g −1 of fish per day) and slow for three trials (0.21 mg TMA-N 100 g −1 of fish per day and 3.7 mg TVB-N 100 g −1 of fish per day). Likewise, the histamine development rate was rapid during one trial (5.4 per day at T amb and 0.313 per day in ice), slow (average rate 3.503 per day during four trials at T amb , 0.305 per day during one trial in ice) and zero during the other three ice-trials. Bacteria multiplied rapidly at T amb ; psychrotrophs multiplied slowly, and represented 10–68% of mesophiles at rejection point. In ice, bacteria multiplied slowly after lag phases of up to 120 h, but reached levels of rejection similar to those observed for T amb storage, H 2 S-producing bacteria represented 0.5–7% of the initial fish flora and 3–10.1% at rejection point. They grew with a shorter lag phase as was the situation with the total flora.
Indion Ina 225H resin as a novel, selective, recyclable, eco-benign heterogeneous catalyst for the synthesis of bis(indolyl)methanes

Abstract Indion Ina 225H, is a heterogeneous, selective, recyclable, and eco-benign catalyst for liquid phase electrophilic substitution reactions of indoles with aldehydes to afford the corresponding bis(indolyl)methanes in excellent yields in short reaction time. The versatility of this method has been proved with a wide range of aliphatic and aromatic aldehydes with various stereo-electronic factors. This method shows much better selectivity between aldehydes and ketones. The methodology is well demonstrated toward the synthesis of biologically active bis(indolyl)methanes viz, vibrioindole, 4-(di(1H-indol-3-yl)methyl)benzene-1,2-diol and streptindole. The catalyst can be recovered and reused for several runs without loss of activity.
Volatile Constituents of Cnidium silaifolium (Jacq.) Simonkai subsp. Orientale (Boiss.) Tutin from Turkey

Abstract The oil obtained by hydrodistillation from the aerial parts of Cnidium silaifolium (JACQ.) Simonkai subsp. orientale (Boiss.) Tutin from Turkey was analyzed by GC and GC-MS. Twenty five compo-nents were characterized, representing 99.8 % of the total components detected and the major compounds were kessane (32.7 %), α-copaene (10.9 %), β-caryophyllene (8.2 %), α-pinene (7.9 %) and δ-cadinene (7.0 %).
Raman study of magnetite (Fe3O4): laser‐induced thermal effects and oxidation

Natural magnetite (Fe3O4) in the form of single crystal and powder was studied by laser Raman spectroscopy at various laser powers. The correlations between the power of the excitation laser, the temperature of the sampled spot and the degree of oxidation of magnetite were accurately established. In the course of the oxidation of the single crystal of magnetite, the first characteristic features of hematite appear at about 300 and 410 cm−1, at a temperature close to 240°C. This may explain the erroneous assignment of these modes to the intrinsic Raman modes of magnetite in some studies. For the finely powdered magnetite, which is much more easily prone to oxidation, the reaction mechanism proceeds via a metastable maghemite (γ-Fe2O3) before the final product hematite is formed. Three independent methods based on the quasi-harmonic approximation and on the ratio of the Stokes to anti-Stokes intensities were used to calculate the local temperature of the laser-heated spot. Temperature-induced shifts of phonon bands were also evaluated. The phonons shift at the following rates: A1g − 0.023(1) cm−1 K−1, T2g(2) − 0.030(2) cm−1 K−1, Eg − 0.019(5) cm−1 K−1 and T2g(1) − 0.00(1) cm−1 K−1. Copyright © 2003 John Wiley & Sons, Ltd.
Low-Temperature Heat Capacities and Thermodynamic Properties of Octahydrated Barium Dihydroxide, Ba（OH）2·8H2O（s）

Low-temperature heat capacities of octahydrated barium dihydroxide, Ba(OH)2·8H2O(s), were measured by a precision automated adiabatic calorimeter in the temperature range from T=78 to 370 K. An obvious endothermic process took place in the temperature range of 345–356 K. The peak in the heat capacity curve was correspondent to the sum of both the fusion and the first thermal decomposition or dehydration. The experimental molar heat capacities in the temperature ranges of 78–345 K and 356–369 K were fitted to two polynomials. The peak temperature, molar enthalpy and entropy of the phase change have been determined to be (355.007±0.076) K, (73.506±0.011) kJ·mol−1 and (207.140±0.074) J·K−1·mol−1, respectively, by three series of repeated heat capacity measurements in the temperature region of 298–370 K. The thermodynamic functions, (HT−H298.15 K) and (ST−S298.15 K), of the compound have been calculated by the numerical integral of the two heat-capacity polynomials. In addition, DSC and TG-DTG techniques were used for the further study of thermal behavior of the compound. The latent heat of the phase change became into a value larger than that of the normal compound because the melting process of the compound must be accompanied by the thermal decomposition or dehydration of 7H2O.