Miracle-dz/UniFAR-FTUs huggingface dataset:
Revisiting the transition between juvenile and mature wood: a comparison of fibre length, microfibril angle and relative wood density in lodgepole pine

Abstract In an attempt to examine the dynamic inter-relationship among wood density and fibre traits [tracheid length and microfibril angle (MFA)] in lodgepole pine (Pinus contorta), 60 trees were sampled in three age classes from four sites in central British Columbia. Breast height discs were taken and relative wood density was measured along two radii. Tracheid length was assessed on isolated 5-year increments from pith to bark at breast height for each tree. MFA was determined every 50 μm and the 5-mm composite intervals from pith to bark per disc at breast height were used in the analysis. Segmented regression was employed to identify the “juvenile to mature wood” transition point, which revealed transition ages of 31, 18 and 15 for wood density, fibre length and MFA, respectively. These traits were related to primary growth, expressed as area increment, ring width, percent earlywood and height increment during the juvenile wood phase. Comparisons of wood and fibre traits showed a higher congruence between the time of transitions for fibre length and MFA (Pearson correlation coefficient 0.52) than that between fibre length and wood density (0.07), and MFA and wood density (0.16). The cessation of early rapid radial increment growth terminated before wood and fibre transitions to mature wood occurred. Fibre length was significantly, but not strongly, related to ring width and percent earlywood (0.35 for both). The duration of juvenile fibre production was not significantly related to height growth.
High sensing response Pd/GaN hydrogen sensors with a porous-like mixture of Pd and SiO2

A metal–semiconductor–metal Pd/GaN hydrogen sensor with a porous-like mixture of Pd and SiO2 is investigated. Besides symmetrically bidirectional sensing characteristics with a widespread voltage regime (at least −5–5 V), a high sensing response of 8 × 105 (7.7 × 106) corresponding to a Schottky barrier height variation of 352 (411) meV is obtained in a 4890 ppm H2/N2 ambience at a voltage of −1.5 (−5) V. A highly efficient dissociation of hydrogen molecules due to an enhanced catalytic activity of the mixture explains the improved performance. Furthermore, dynamic responses by alternately switching voltage polarity and introducing and removing hydrogen-containing gases are also included to evaluate the proposed device as a high sensing response and low power sensor.
Effect of Silicon on Plant Growth and Mineral Nutrition of Maize Grown Under Water-Stress Conditions

ABSTRACT The effect of silicon (Si) on physiological attributes and nutritional status of maize (Zea mays cv. DK 647 F1) under water stress was studied in a pot experiment. Treatments were (1) well watered (WW): 100% of FC (soil field capacity), (2) WW + Si1: 100% of FC + 1 mM Si, (3) WW + Si2: 100% of FC + 2 mM Si, (4) water stress (WS): 50% of FC, (5) WS + Si1: 50% of FC + 1 mM Si and (6) WS + Si2: 50% of FC + 2 mM Si. In the control treatment, plants were irrigated to field capacity (100% FC). Water stress was imposed by maintaining a moisture level equivalent to 50% of field capacity, whereas the well-watered pots (control) were maintained at full field capacity. Water stress was found to reduce the total dry matter (DM), chlorophyll content, and relative water content (RWC), but to increase proline accumulation and electrolyte leakage in maize plants. Both Si treatments largely improved the above physiological parameters, but levels remained significantly lower than the control (WW) values except for electrolyte leakage and root:shoot ratios, which were higher. Only root DM appeared to show very little variation in any of the treatments. The concentration of Si in the plants was increased by Si addition into the nutrient solution. Water stress reduced leaf calcium (Ca) and potassium (K) of maize plants, but addition of Si increased these nutrient levels; Ca levels were similar to WW under the high-Si treatment, but K was lower. Root Ca and K were both increased by WS; root Ca was further increased by high Si (WS + Si2 treatment). Addition of Si to the WS treatments did not change root K. Results indicate that while application of Si may be one approach to improve growth of this crop and increase its production in arid or semi-arid areas where water is at a premium, this technique would not fully substitute for an adequate water supply.
Root and aboveground growth of rhizotron-grown seedlings of three Tunisian desert Calligonum species under water deficit

Dhief, A. , Abdellaoui, R. , Tarhouni, M. , Belgacem, A. O. , Smiti, S. A. and Neffati, M. 2011. Root and aboveground growth of rhizotron-grown seedlings of three Tunisian Desert Calligonum species under water deficit. Can. J. Soil Sci. 91: 15–27. In southern Tunisia, plants are subjected to severe drought and many human disturbances, causing the degradation of soils and plants. The study of wild plants and their response to water deficit can facilitate their conservation and help in ecosystem rehabilitation. In this context, the adaptive responses to water deficit of three desert Calligonum species (C. comosum L'Herit, C. azel Maire and C. arich Le Houerou), differing in their topographic location, were studied in rhizotrons under two water regimes. The objectives were to correlate the adaptive ability of these species, with several developmental traits, such as root architecture and growth, aerial growth and height, with environmental and soil properties, and to define which of the three Calligonum species .
Noninvasive Quantification of Green Fluorescent Protein Labeled Escherichia coli in a Dynamic Capillary Fringe by Fluorescence Intensity

Quantification of bacteria attached to sand grains is usually not possible without destroying biofilms or the sand structure. In situ quantification of autofluorescing or of fluorescence‐carrying bacteria might be an alternative if fluorescence intensity (FI) was strong enough and could be related to cell numbers. For calibration, a Hele–Shaw cell was filled with sterile quartz sand and sectioned for inoculation with increasing cell densities of Escherichia coli strain HB101 K12 pGLO, overexpressing green fluorescent protein (GFP). Digital photographs of the single sections were taken under ultraviolet light at wavelength λ = 365 nm for fluorescence quantification by TotalLab Quant software. The FI was related to respective cell densities per quartz sand volume. Growth of GFP‐labeled E. coli, suspended in Lysogeny broth (LB) medium (dissolved organic C = 6.8 g L−1), could thus be quantified noninvasively in capillary fringe (CF) laboratory systems simulating static or hydrodynamic conditions. Best growth conditions existed in the transition zone of the CF, where after 3 d the highest cell densities of 5.0 to 6.5 × 108 cells cm−3 were determined. The E. coli cells that grew attached as a biofilm in the different sections of the CF could also be quantified under flow‐through conditions and after fluctuation of the water table. For reliable results, FI calibration must be performed in the same setup as used for experiments, and fluorescence characteristics of the bacterial strain should be well known. This noninvasive method using bright fluorescing bacteria can be advantageous for the determination of bacterial growth and biofilm formation in laboratory experiments with unsaturated soil under changing hydraulic conditions.
On the formation mechanisms of the diffuse atmospheric pressure dielectric barrier discharge in CVD processes of thin silica-like films

Pathways of formation and temporal evolution of the diffuse dielectric barrier discharge at atmospheric pressure were experimentally studied in this work by means of optical (fast imaging camera) and electrical diagnostics. The chosen model system is relevant for applications of plasma-enhanced chemical vapor deposition of thin silica-like film on the polymeric substrate, from cost-efficient gas mixtures of Ar/N2/O2/hexamethyldisiloxane. It was found that the discharge can gradually experience the phases of homogeneous low current Townsend-like mode, local Townsend to glow transition and expanding high current density (∼0.7 A cm−2) glow-like mode. While the glow-like current spot occupies momentarily only a small part of the electrode area, its expanding behavior provides uniform treatment of the whole substrate surface. Alternatively, it was observed that a visually uniform discharge can be formed by the numerous microdischarges overlapping over the large electrode area.
Quasilinear evolution of non-thermal distributions in ion cyclotron resonance heating of tokamak plasmas

The AORSA global-wave solver is combined with the CQL3D bounce-averaged Fokker-Planck code to simulate the quasilinear evolution of non-thermal distributions in ion cyclotron resonance heating of tokamak plasmas. A novel re-formulation of the quasilinear operator enables calculation of the velocity space diffusion coefficients directly from the global wave fields. To obtain self-consistency between the wave fields and particle distribution function, AORSA and CQL3D have been iteratively coupled using Python. The combined selfconsistent model is applied to minority ion heating in the Alcator C-Mod tokamak. Results show the formation of a 70 keV ion tail near the minority ion cyclotron resonance layer in approximate agreement with measurements from charge exchange neutral particle analyzers.
Are Ination Expectations Rational?

Several recent papers report evidence of an apparent statistical bias in ination expectations and interpret these ndings as overturning the rational expectations hypothesis. In this paper, we investigate the validity of such an interpretation. We present a computational dynamic general equilibrium model capable of generating aggregate behavior similar to the data along several dimensions. By construction, model agents form rational expectations. We run a standard regression on equilibrium realizations of ination and ination expectations over sample periods corresponding to those tests performed on actual data and nd evidence of an apparent bias in ination expectations. Our experiments suggest that this incorrect inference is largely the product of a small sample problem, exacerbated by short-run learning dynamics in response to infrequent shifts in monetary policy regimes. Keywords: Regime changes; Learning dynamics; Monte Carlo experiments; Sample size. JEL classi cation: E47, E52, E58 Corresponding author. Kevin Moran, Economics Department, Université Laval, Québec (QC) G1K7P4 Canada. Email: kmoran@ecn.ulaval. ca. Phone: 1 418 656 2131x5870. Fax: 1 418 656 2707. yWe thank Bob Amano, Paul Gomme, Ken Kasa, Andrew Levin, Césaire Meh, and seminar participants at the 2003 Annual De Nederlandsche Bank Conference for useful comments. We would especially like to thank Martin Eichenbaum and our referees for their constructive criticisms and help. Andolfatto acknowledges the nancial support of SSHRC. Are Ination Expectations Rational? 2 Are Ination Expectations Rational? 3
Use of Infrared Spectroscopy to Study Geopolymerization of Heterogeneous Amorphous Aluminosilicates

Geopolymerization is a general term to describe all the chemical processes that are involved in reacting aluminosilicates with aqueous alkaline solutions to produce a new class of inorganic binders called geopolymers. In the present work, a novel analytical procedure is developed to study geopolymerization of amorphous aluminosilicates in real time. This procedure involves first conducting a series of well-designed leaching experiments, within which an aluminosilicate is alkali-activated with aqueous alkaline solutions of varying alkalinities and soluble silicate dosages. The leached solutions are diluted and analyzed using inductively coupled plasma equipped with optical emission spectroscopy (ICP−OES), and the activated solid particles are separated, washed, desiccated, and analyzed by Fourier transform infrared (FTIR) spectroscopy. By comparing the results obtained from the ICP−OES and the FTIR analyses, a linear calibration curve can be constructed to correlate the extent of the alkali-activation of t.
A New Bis(dithioester): Methanediyl Bis(N,N-diethyldithiocarbamate), Derived from cis-Dichlorobis(N,N-diethyldithiocarbamato-S,S')tin(IV)

The title compound, C11H22N2S4, [or CH2(Et2DTC)2, where DTC is dithiocarbamate], was unexpectedly obtained during studies on the reactivity of cis-dichlorobis(N,N-diethyldithiocarbamato-S,S′)tin(IV) {cis-[Cl2Sn(Et2DTC)2]} with 2-thiouracil in dimethyl sulfoxide. The X-ray structural analysis of the title compound shows that two N,N-diethyldithiocarbamate units are linked together through a methylene carbon atom, so that the compound can be described as a dithioester where the –CH2(N,N-diethyldithiocarbamate) group itself constitutes the esteric organic radical. Structural parameters and IR spectra are in agreement with the crystal chemistry of this class of compounds. Of major interest is the methylene carbon atom, which presents a S—CH2—S angle of 116.9 (2)°, larger than the ideal tetrahedral value of 109.47°.
Degradation of phthalate esters (PAEs) in soil and the effects of PAEs on soil microcosm activity

BACKGROUND: Phthalate esters (PAEs), a class of refractory and toxic organic compounds, are becoming one of the most widespread contaminants in the environment. Degradation of PAEs in soil has been investigated, but limited to one or a few kinds of PAEs. Microorganisms could be regarded as a sensitive bio-indicator for soil contaminants. Therefore, four commonly used PAEs were chosen to investigate their degradation patterns and potential impacts on soil microbial activity with a series of bioassays. RESULT: PAEs in sterile soils changed slightly, while degradation of PAEs in non-sterile soil followed a single first-order kinetic. Higher concentrations of PAEs led to lower β-glucosidase activity and higher protease activity, with smooth changes of phosphatase and urease activities. PAEs decreased average well color development (AWCD), while Shannon index (H) showed a tendency to increase after a decrease. Carbon utilization profile was affected significantly by PAEs, especially at 10 mg kg−1 soil. CONCLUSION: Degradation of PAEs was driven mainly by microbial mediated processes. PAEs affected carbon, nitrogen and phosphorus cycles variously, and had temporal effects on metabolic diversity, owing to the adaptation of microbes. Carbon substrates utilization changed from easily degradable sugars and carboxylic acids to recalcitrant compounds during the simulation. Copyright © 2010 Society of Chemical Industry
Compositional nonuniformities in pulsed laser atom probe tomography analysis of compound semiconductors

The unidirectional laser illumination of atom probe tomography specimens can result in changes of the apex morphology from nearly hemispherical to asymmetrical with different local radii of curvature, implying an anisotropic field distribution across the sample surface. In the analysis of III-V semiconductors, this affects the process of field dissociation of group-V cluster ions and introduces variations in the apparent composition across the field of view. We have studied this phenomenon in GaSb and propose an explanation for these compositional variations in terms of the locally varying extent of field dissociation of group-V cluster ions and ion pile-up effects on the detector. The optimization of experimental conditions and possible modifications to the instrument design are discussed to mitigate the compositional variations.
Constitutive activation of AtMEK5, a MAPK kinase, induces salicylic acid-independent cell death in Arabidopsis thaliana

AtMEK5DD is an active mutant of AtMEK5, a MAP kinase kinase in Arabidopsis. Induction of AtMEK5DD expression in transgenic plants leads to activation of 44 and 48 kD MAPKs and causes a rapid cell death. To compare the cell death induced by the expression of AtMEK5DD with the HR-cell death induced by avirulence pathogen infection, we analyzed the activation of downstream MAP Kinase and induction of PR genes expression in permanent transgenic Arabidopsis plants. In-gel kinase activity assay revealed that the infection of Pseudomonas syringae DC3000 harboring Avr Rpt2 gene also lead to activation of 44 and 48 kD MAPKs. PAL, PR1 and PR5 were strongly induced in plants undergoing HR-cell death caused by the infection of P. syringae DC3000, while only the expression of PR5 was strongly induced in transgenic plants expressing AtMEK5DD protein. NahG protein in AtMEK5DD × NahG plants cannot suppress the cell death induced by AtMEK5DD. And AtMEK5DD protein expressed AtMEK5DD × NahG plants showed no significant change in salicylic acid (SA) level. All these suggest that the cell death induced by the activation of AtMEK5 is salicylic acid-independent.
Synthesis of spherical FePd and CoPt nanoparticles

Co48Pt52 nanoparticles were prepared by the simultaneous chemical reduction of platinum acetylacetonate and the thermal decomposition of cobalt tricarbonyl nitrosyl. Similarly, Fe50Pd50 nanoparticles were prepared by the simultaneous reduction of palladium acetylacetonate and the thermal decomposition of iron pentacarbonyl. The average diameter for the Co48Pt52 particles was 7 nm, while the average diameter for the Fe50Pd50 particles was 11 nm. Films of the particles were cast onto silicon wafers from hydrocarbon solution. Only after annealing at 700 °C for three hours did the Co48Pt52 films transform to the L10 phase. However there was no evidence for the tetragonal phase for the films containing Fe50Pd50 particles after annealing at 700 °C for three hours.
Nutrient Dynamics in a Long‐Term Cereal‐Based Rotation Trial in a Mediterranean Environment: Nitrogen Forms

Mediterranean agriculture is mainly rainfed, with drought being the main crop production constraint, and is based on cereals, wheat (Triticum spp), and barley (Hordeum vulgare). Fallow was a traditional practice to conserve soil moisture, but because of land‐use pressure it is giving way to cereal monoculture, which is unsustainable. The substudy reported here was part of a long‐term rotation trial that sought to examine alternative crop rotation options, that is, durum wheat (T. durum var durum) in rotation with fallow, summercrop (melon, Citrullus vulgaris), wheat (continuous cropping), chickpea (Cicer arietinum), lentil (Lens culinaris), vetch (Vicia sativa), and medic (Medicago spp). Ancillary treatments involved nitrogen (N) applied to the cereal phase and variable stubble grazing intensity (stubble retention, medium grazing, and heavy grazing or complete stubble removal). This substudy, conducted in the final 3 years of the 14‐year trial, involved sampling soil and plants within the cropped rotation plots and sampling soil within bare microplots in selected larger rotation plots. We measured N forms in soil samples at different depths and throughout the seasons. Despite variation within and between seasons, the rotation effect of enhanced N was significant and consistent, being highest for vetch and medic, intermediate for chickpea and lentil, and least for continuous cereal, summer crop, and fallow. Therefore, legume‐based cereal rotations can enhance soil N and thus save on N fertilizer. In bare microplots, total N decreased, labile N was inconsistent, mineral N increased, and biomass N increased and remained stable during the cropping season and then sharply declined. The nutrient dynamic data complemented the crop yield, water‐use efficiency, and soil aggregation data from the trial to support the argument for using legumes in cereal rotations in place of fallow and continuous cereal cropping.
Conversion of nitrogen dioxide, nitric acid, and n-propyl nitrate to nitric oxide by gold-catalyzed reduction with carbon monoxide

A new technique is described for the real-time, quantitative conversion of several XNO/sub 2/ compounds to NO, where X denotes a radical group. The technique utilizes the reduction of these compounds by CO at heated gold catalyst to yield NO. The NO product was detected by a sensitive chemiluminescence detector. The technique was demonstrated to convert NO/sub 2/, HNO/sub 3/, and n-propyl nitrate quantitatively to NO for mixing ratios in the range of 1-120 ppbv in synthetic air at atmospheric pressure. Conversion results were obtained for CO mixing ratios in the range of 0.2-1000 ppmv and for temperatures in the range of 20-600 /sup 0/C. The Gormley-Kennedy equation was used to analyze the results for consistency with known diffusion coefficients. The CO reduction process is discussed in terms of the thermochemistry of the net conversion reactions and catalytic properties of the gold surface. In addition, the potential of this technique for atmospheric measurements is noted. 8 figures, 3 tables.
An Aerosol Wind Tunnel for Evaluation of Massive-Flow Air Samplers and Calibration of Snow White Sampler

Massive-flow air samplers are being deployed around the world to collect aerosol samples for analysis of radioactivity as a result of nuclear tests and nuclear accidents. An aerosol wind tunnel capable of an 1100 m3 min−1 flow rate was built at Lovelace Respiratory Research Institute (LRRI) to test the sampling efficiency of these samplers. This aerosol wind tunnel uses a stationary air blender to enhance mixing, and therefore it achieves the required uniform distribution of wind speed and aerosol concentration in the test section. The test section of the wind tunnel has a cross section that is 4.3 m × 3.7 m. The aerosol wind tunnel was tested for performance in terms of distribution of wind speed, turbulent intensity, SF6 tracer gas concentration, and aerosol concentration. Test criteria consistent with U.S. Environmental Protection Agency (EPA) and American National Standards Institute (ANSI) standards were adopted as the guidelines for the aerosol wind tunnel. Additional criteria for aerosol wind tunnel were also recommended. Initial test of the aerosol wind tunnel showed that the wind tunnel could be operated in a wind speed range of 2 to 24 km h−1. Within this range, the distribution of wind speed SF6 trace gas concentration and aerosol concentration in two-thirds of the central area of the test section showed coefficient of variances (COVs) of less than 10% for the range of wind speeds. This met the stringent guidelines for aerosol wind tunnel performance set by EPA and ANSI standards. The LRRI wind tunnel was used to evaluate the collection efficiency of the sampling head of massive-volume air samplers, including the Snow White sampler. The sampler was tested in this aerosol wind tunnel for particles between 2 and 20 μm. The sampling flow rates were 500 and 700 m3 h−1 for the tested wind speeds of 2.2 and 6.6 m S−1, respectively. The results showed that sampling efficiency was influenced by both sampling flow rate and wind speed. The sampling efficiency decreased with an increase in particle size of between 2 and 20 μm. The sampling efficiency also decreased as the wind speed was increased from 2.2 to 6.6 m S−1.