Miracle-dz/UniFAR-FTUs huggingface dataset:
Estimates of phosphorus entrainment in Lake Mendota: a comparison of one‐dimensional and three‐dimensional approaches

Entrainment of phosphorus across the thermocline can be an important nutrient source for phytoplankton in stratified lakes. In eutrophic stratified lakes, seasonal entrainment can be responsible for delayed recovery following a decrease in external phosphorus load. We compared seasonal estimates of entrainment derived from single‐ and multilocation thermocline migration approaches. Entrainment estimates from these methods were similar. A sampling approach based on a single centralized location produced whole‐lake entrainment estimates in general agreement with the mean value from the multilocation approach (the single‐location approach reasonably reproduced patterns at a weekly and seasonal time scale). In this study, it was not essential to account for spatial variation in estimating annual rates of entrainment. We also estimated entrainment based on a three‐dimensional (3‐D) hydrodynamic model over a short period of significant thermocline migration. The 3‐D model was most useful in exposing spatial and temporal variation in temperature and phosphorus profiles that are otherwise difficult to observe. Spatial variation in phosphorus profiles was associated with upwelling of metalimnetic water represented by the 3‐D model. These transient dynamics, though a relatively small portion of an annual phosphorus budget, may supply nutrients to epilimnetic phytoplankton during periods of nutrient limitation. There is a need for further research that combines 3‐D hydrodynamic modeling with field collection of biological and chemical data.
Iodine in sea ice and the polar atmosphere.

The volatilisation of iodine from the ocean and release to the atmosphere in the ice-covered polar regions has been studied. Laboratory experiments involving sea ice- and ice associated- diatoms have shown how the extreme conditions experienced in sea ice brine channels may lead to an increase in production of organic forms of iodine. Trends were observed in production by different classes of enzymes, active in the oxidative metabolism of the cell. An enhancement in trace gas concentrations due to the concentration effect of solvent volume reduction has also been demonstrated. Field campaigns have been undertaken in both the Arctic and Antarctic. Ship-based measurements in the Weddell Sea have implicated I2 as a key species in the mechanism of enhancement of atmospheric iodine in this region. Organic and inorganic forms of iodine were measured in seawater, sea ice and the atmosphere. On the Brunt ice shelf, enhanced concentrations of CH3I and C2H5I were measured in the snow firn air, with a diurnal profile, suggesting the snow may be a source of these compounds. These measurements have implications for atmospheric mixing ratios of IO, measured from the ship and validated by satellite data, and new particle formation. This is the first combined in situ study in Antarctica of organic and inorganic iodine compounds in sea water, ice and air. On the Western Antarctic Peninsula, IO was detected in the atmosphere, and seawater measurements of iodocarbons have demonstrated how organic compounds of iodine are enhanced during the phytoplankton bloom; these measurements are also a first. Iodine emissions in the sea ice zone were also quantified in two campaigns in the Arctic environment. High concentrations of halocarbons were measured in the brine of sea ice, with respect to the water below, in the Arctic Ocean. High atmospheric halocarbon mixing ratios and flux calculations have demonstrated the effect on the atmosphere above. In the Canadian sub-Arctic, where the ice had quite different physical properties, halocarbon concentrations were the highest ever recorded for some compounds, due to extreme concentration in very cold ice. The enhancement of organic forms of iodine in sea ice has therefore been demonstrated. I2 has been implicated as a key species in iodine emissions. Therefore, understanding has been furthered on the chemistry of iodine in sea ice and polar atmosphere.
An Experimental Investigation of Mixing in Two-Dimensional Turbulent Shear Flows with Applications to Diffusion-Limited Chemical Reactions

The extent of molecular mixing in several two-dimensional free turbulent shear flows was measured using a concentration probe with a frequency response of 100 kHz and a spatial resolution of 0.1 mm. The flows investigated were (i) a shear layer in which the gases on either side of the layer are of unequal density, (ii) a shear layer in which the gases on either side of the layer are of equal density, and (iii) a wake in which the gases on either side of the wake are of unequal densities. The extent of mixing was measured as a function of Reynolds number for the first case. It was found that at a critical Reynolds number the extent of molecular mixing sharply increased (25%). Power spectral density curves of the concentration time histories also indicated a marked increase in the high frequency fluctuations above this Reynolds number. A shadowgraph investigation of this phenomenon revealed that three-dimensional Taylor-type vortices whose axes of rotation are basically in the flow direction exist in the flow in addition to the two-dimensional large structures previously observed. These Taylor vortices were found to be unstable above the critical Reynolds number and were producing the increase in molecular mixing. The growth and development of the two-dimensional large structures were found to be basically unaffected by this instability. It is proposed that the fully developed turbulence of shear flows is maintained by a combination of the development of the large structures and of the coupling between the large structures and these unstable Taylor vortices. These data were also used to predict results for shear flows in which diffusion-limited chemical reactions have been incorporated.
Atomic and molecular hydrogen gas temperatures in a low-pressure helicon plasma

Neutral gas temperatures in hydrogen plasmas are important for experimental and modelling efforts in fusion technology, plasma processing, and surface modification applications. To provide values relevant to these application areas, neutral gas temperatures were measured in a low pressure (< ? >10 mTorr) radiofrequency helicon discharge using spectroscopic techniques. The atomic and molecular species were not found to be in thermal equilibrium with the atomic temperature being mostly larger then the molecular temperature. In low power operation (< ? >1 kW), the molecular hydrogen temperature was observed to be linearly proportional to the pressure while the atomic hydrogen temperature was inversely proportional. Both temperatures were observed to rise linearly with input power. For high power operation (5–20 kW), the molecular temperature was found to rise with both power and pressure up to a maximum of approximately 1200 K. Spatially resolved measurements near a graphite target demonstrated localised cooling near the sample surface. The temporal evolution of the molecular gas temperature during a high power 1.1 ms plasma pulse was also investigated and found to vary considerably as a function of pressure.
Nutritive value of rice polish.

The present study was undertaken to observe the chemical composition of different types of rice polish available in different areas of Chittagong, Bangladesh. Twenty different types of rice polishes were collected from study areas. Chemical analyses of the samples were carried out in triplicate for moisture, dry matter (DM), crude protein (CP), crude fiber (CF), nitrogen free extract (NFE), ether extract (EE) and total ash (TA) in the animal nutrition laboratory, Chittagong Veterinary and Animal Sciences University, Chittagong, Bangladesh. Metabolizable energy (ME) was calculated mathematically for all samples by using standard formula. Results indicated that, there were no marked variations (P>0.05) in the moisture, DM and TA contents of the samples. However, ME, CP, CF, NFE and EE content significantly differed (P0.01) from one sample to another. Moisture content varied from 4.0 to 11.4 g/100g, DM content varied from 88.6 to 96.0 g/100g, ME content varied from 1321.8 to 3086.9, CP content varied from 4.7 to 14.9 g/100g, CF content varied from 6.4 to 41.5 g/100g, EE content varied from 1.0 to 18.0 g/100g, NFE content varied from 25.1 to 52.9 g/100g and TA content varied from 7.1 to 17.6. It could therefore, be inferred that, the chemical composition rice polish currently available in the local market are widely variable.
Effect of electrical stimulation of nigrostriatal dopaminergic neurons on utilization of exogenous L‐dopa in rat corpus striatum

The rates of synthesis and release of dopamine (DA) by striatal D A nerve-terminals are largely determined by the firing activity of DA neurons in the substantia nigra (Korf 1979). Thus, when impulse flow is enhanced in the nigrostriatal projection such as during electrical stimulation, there is an accelerated release of DA synthesized from tyrosine and the dopa formed from tyrosine hydroxylation; this is manifested biochemically by elevated striatal levels of 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) with essentially unchanged D A concentrations (Korf et al 1976; Roth et al 1976). While hyperactive DA neurons increase formation and release of DA from endogenous tyrosine and dopa, it is of interest whether they are also capable of utilizing more exogenously administered precursors. There is some evidence indicating that exogenous tyrosine may increase DA synthesis and release but only by rapidly firing and not by resting DA neurons; this effect may be linked to activation of tyrosine hydroxylase (Scally et al 1977; Melamed et a1 1980a). In contrast, systemic L-dopa enhances striatal D A synthesis and release even by non-activated DA neurons, since dopa decarboxylase is not a rate-limiting enzyme in the biosynthesis of catecholamines (Melamed et a1 1980b; Hefti & Melamed 1981b). However, it remains unknown whether acceleration of impulse flow is associated with increased utilization of exogenous L-dopa by DA neurons. This question is important concerning the mechanism of action of L-dopa in Parkinson's disease and mainly the striatal locus of its enzymatic decarboxylation to D A after degeneration of D A terminals. Clinical and experimental studies indicate that when the nigrostriatal projection is partially destroyed, the remaining neurons become hyperactive and synthesize and release more DA from endogenous precursors than do neurons in an intact system (Agid et a1 1973; Bernheimer et a1 1973; Hefti et all980). On that basis, it was hypothesized that L-dopa's efficacy in Parkinsonism depends on its accelerated utilization by the surviving hyperactive DA neurons which might be capable of converting exogenous L-dopa to DA in amounts adequate to correct the deficient DA neurotransmission despite their markedly small numbers (Hornykiewicz 1974).
Correlation between theory and data for mechanisms leading to dielectric breakdown

The charge-to-breakdown (Q/sub bd/) and time-to-breakdown (t/sub bd/) have been measured for 10-nm oxides in the range of 10-16 MV/cm, at 30/spl deg/C and 150/spl deg/C on N-FETs. These data strongly suggest two distinct physical mechanisms contributing to oxide breakdown. Based on model calculations, the mechanisms are attributed to trap creation and impact ionization. <<ETX>>
Monte Carlo simulation of the adsorption of C2–C7 linear alkanes in aluminophosphate AlPO4-11

The adsorption behaviors of linear alkanes ranging in length from C2 to C7 in AlPO4-11 have been simulated by using configurational-bias Monte Carlo technique at 313 K. The calculated heats of adsorption at zero coverage for linear alkanes, estimated by Henry coefficients, are consistent well with previously reported experimental and simulation results. The simulated isotherms for n-hexane in AlPO4-11 at 298 K agree with the experimental data. The isotherms of C2–C7 linear alkane were predicted, in which butane presents a substep. The adsorbed alkane molecules are only localized in 10-membered ring channels, and adsorbed phase structures for each alkane were investigated. Total potentials for individual alkane molecule decrease with increasing number of carbon atoms. A linear change in total potential is observed for each linear alkane with increasing loading per unit cell, except that an increasing trend is found in the total potential curve of butane as the loading per unit cell is higher than two molecules.
Rapid manual determination of sulfur and phosphorus in plant material

Abstract Rapid manual techniques have been developed for the determination of sulfur and phosphorus in plant material. After digestion with magnesium nitrate solution and perchloric acid, sulfur is determined turbidimetrically using Tween 80 as a stabiliser, while phosphorus is determined colorimetrically as the vanado‐molybdate complex. Samples can be analysed for both sulfur and phosphorus at the rate of 100 samples per man‐day, with a minimum capital outlay.
DETERMINAÇÃO DE RESÍDUOS DE 2,4D EM AMOSTRAS VEGETAIS

Adaptou-se metodologia existente para determinacao de residuos do herbicida 2,4D (acido 2,4 diclorofenoxiacetico) em matrizes vegetais. A metodologia proposta foi testada em amostras de cana-de-acucar, arroz, milho, soja e trigo. O 2,4D foi extraido com diclorometano em meio acido e derivados foram submetidos ao cleanup em minicolunas de florisil, para entao serem quantificados por cromatografia gasosa com detector de captura de eletrons. a recuperacao apresentou-se na faixa de 76-94%.
Impacts of 48 years of consistent cropping, fertilization and land management on the physical quality of a clay loam soil

Reynolds, W. D. , Drury, C. F. , Yang, X. M. , Tan, C. S. and Yang, J. Y. 2014. Impacts of 48 years of consistent cropping, fertilization and land management on the physical quality of a clay loam soil. Can. J. Soil Sci. 94: 403-419. Soil physical quality (SPQ) is often ignored or under-monitored in long-term field studies designed to determine the economic and environmental sustainability of agricultural practices. Accordingly, a suite of complementary soil physical and hydraulic parameters was measured using intact core samples to determine the SPQ of a Brookston clay loam under a long-term (48 yr) cropping, fertilization and land management study at Woodslee, Ontario. The SPQ under virgin woodlot, fertilized monoculture sod and unfertilized monoculture sod treatments was similar, with optimal SPQ occurring in the top 10-20 cm, but severely suboptimal SPQ occurring below 30 cm because bulk density (BD), relative field capacity (RFC) and saturated hydraulic conductivity (KS) were excessive, and because organic carbon (OC), air capacity (AC) and plant-available water capacity (PAWC) were critically low. The SPQ for fertilized and unfertilized monoculture corn under fall moldboard plow tillage was similar and substantially suboptimal throughout the top 40-50 cm due to high or excessive BD and RFC, critically low OC, low or critically low AC and PAWC, and KS that varied erratically from excessive to critically low. The SPQ under fertilized and unfertilized corn-oat-alfalfa-alfalfa rotations (corn and second-year alfalfa fall plowed) was similar and largely non-optimal below 10 cm, but largely optimal in the top 10 cm due to the ameliorating effects of numerous biopores and crop roots. A bimodal soil water release function fitted to release curve data showed that PAWC was determined by soil matrix porosity (PM), and AC was determined by soil structure porosity (PS). Strong inverse linear correlations between BD vs. PM, BD vs. PS and BD vs. OC provided site-specific estimates of optimal ranges and critical limits for PAWC, AC and OC, respectively. Although SPQ changed substantially among treatments, the changes did not extend below 30-to 40-cm depth, and were largely unaffected by long-term annual fertilization. The SPQ below 30- to 40-cm depth was similarly poor across all treatments, and is likely an inherent characteristic of the soil.
Scale effects on the heat release rate, smoke production rate, and species yields for a vegetation bed

The burning of a vegetation bed was investigated employing the cone calorimeter and the furniture calorimeter for testing on a small and a large scale. Heat release rate, smoke production rate, and species yields were measured at both scales and with two different setups at the full scale. The results show a clear influence of the scale on: the peak of heat release rate, the smoke extinction area, the soot yield, and the rate of smoke release. The species yields appear to depend not only on the burning scale but also on the experimental setup. This study clearly shows that even for litter with high packing ratio, the results obtained at bench scale cannot be extended directly to the full scale.
Uptake of calcium nitrate and potassium phosphate from foliar fertilization by tomato

The spectrum of materials known to be absorbed by plant foliage has become exceedingly broad. To determine, the effect of different levels of nitrogen and potassium solution on the yield and quality of tomato, a two factor completely randomized experimental design (CRD) with three replications was conducted with `Maha` cultivar in an unheated plastic tunnel. Nitrogen and potassium solution from the source calcium nitrate and potassium phosphate were used with an amount of 4, 6 and 8 and 2, 4 and 6 mmolL-1 respectively. Results of presented experiment revealed different effects of calcium nitrate and potassium phosphate as foliar nutrition and the interaction of these fertilizers on the yield and quality of tomato. The results of this experiment demonstrated that tomato crops fertilized with 6 mmolL-1 calcium nitrate and 4 mmolL-1 potassium phosphate contained greater quality. Key words: Nitrogen, potassium, foliar nutrition, yield, quality, tomato.
Detonation cell size measurements in high-temperature hydrogen-air-steam mixtures at the BNL high-temperature combustion facility

The High-Temperature Combustion Facility (HTCF) was designed and constructed with the objective of studying detonation phenomena in mixtures of hydrogen-air-steam at initially high temperatures. The central element of the HTCF is a 27-cm inner-diameter, 21.3-m long cylindrical test vessel capable of being heating to 700K {+-} 14K. A unique feature of the HTCF is the {open_quotes}diaphragmless{close_quotes} acetylene-oxygen gas driver which is used to initiate the detonation in the test gas. Cell size measurements have shown that for any hydrogen-air-steam mixture, increasing the initial mixture temperature, in the range of 300K to 650K, while maintaining the initial pressure of 0.1 MPa, decreases the cell size and thus makes the mixture more detonable. The effect of steam dilution on cell size was tested in stoichiometric and off-stoichiometric (e.g., equivalence ratio of 0.5) hydrogen-air mixtures. Increasing the steam dilution in hydrogen-air mixtures at 0.1 MPa initial pressure increases the cell size, irrespective of initial temperature. It is also observed that the desensitizing effect of steam diminished with increased initial temperature. A 1-dimensional, steady-state Zel`dovich, von Neumann, Doring (ZND) model, with full chemical kinetics, has been used to predict cell size for hydrogen-air-steam mixtures at different initial conditions. Qualitatively the model predicts the overall trends observed in the measured cell size versus mixture composition and initial temperature and pressure. It was found that the proportionality constant used to predict detonation cell size from the calculated ZND model reaction zone varies between 10 and 100 depending on the mixture composition and initial temperature. 32 refs., 35 figs.
Mid-Season Recovery from Nitrogen Stress in Winter Wheat

ABSTRACT Although spring-applied nitrogen (N) has been shown to be most efficient, the technique of delaying all N applications until mid-season, and the resultant effect on maximum yields, has not been thoroughly evaluated. This experiment was conducted to determine if potential yield reductions from early-season N stress can be corrected using in-season N applications. Data from three experimental sites and two growing seasons (six site-year combinations) were used to evaluate three preplant N rates (0, 45, and 90 kg ha−1) and a range of in-season topdress N rates. Topdress N amounts were determined using a GreenSeeker hand-held sensor and an algorithm developed at Oklahoma State University. Even when early-season N stress was present (0-N preplant), N-applied topdress at Feekes 5 resulted in maximum or near-maximum yields in four of six site-year combinations when compared with other treatments receiving both preplant and topdress N. *Contribution from the Oklahoma Agricultural Experiment Station.
In-Situ Electrochemical Functionalization of Reduced Graphene Oxide: Positive Lead Acid Case

Reduced graphene and graphene oxide sheets have been in-situ functionalized during electrochemical reactions in lead-acid cathode system. This research investigated the comparative differences in surface chemistry of reduced graphene and graphene oxide sheets, and their influence on electrochemical activity within the lead acid charge and discharge reactions. The reduction of graphene oxide sheets was due to activity of OH - and H + groups, and the grafting of HSO 4- and PbO(OH) + ions from PbO…OH - gel zone intermediate complex, via covalent and non-covalent means, is determined to facilitate the ionic reactions at interphase zone of the positive active material.
Evaluación de la calidad durante el almacenamiento de nueces Pecán [Carya illinoinensis (Wangenh.) C. Koch] acondicionadas en diferentes envases

In the present work, the quality changes of pecan nuts stored in nylon-polyethylene plastic film under vacuum and in polypropylene plastic recipients at ambient temperature for 150 days were evaluated. The nutritional composition, fatty acid composition and tocopherol content of the pecan nuts reveal interesting nutritional characteristics and an oil with high contents of mono-unsaturated fatty acids and γ-tocopherol. During storage, moisture content did not suffer significant changes, but a gradual and significant darkening of the surface of the nuts occurred. The changes in acid value, peroxide value and specific extinction of the extracted oil were significant. The microbiological quality was excellent and the presence of Salmonella sp. was not detected. Through sensory analysis, the shelf-life of the product was determined as 120 days, without significant differences between the two types of packaging used.
The Effects of Phosphate Fertilizers and Manure on Maize Yields in South Western Kenya

ABSTRACT Phosphorus, nitrogen and Striga hermonthica are the major constraints to maize production in the Nyanza Province of Kenya. Field trials were conducted on-farm in Nyanza Province to investigate the effects of phosphate fertilizers and manure on maize yields. The experimental design was a Randomized Complete Block Design (RCBD) with maize as the test crop. The maize was top dressed with calcium ammonium nitrate (CAN) fertilizer at a uniform rate of 30 kg N/ha diammonium phosphate (DAP), Minjingu rock phosphate (MRP) and triple super phosphate (TSP) fertilizers were applied at 60 kg/ha P2O5, farmyard manure (FYM) at 10 t/ha and a non-phosphorus (P) treatment (control) plus lime only. Responses (P ≤ 0.01) from grain yield, total dry matter yield and harvest index to phosphate fertilizers and manure treatments were found. Nutrient uptake and removal by the crop increased (P ≤ 0.01) due to fertilizers and manure application. Phosphate fertilizers and manure application increased (P ≤ 0.01)) available soil P, agronomic phosphorus use efficiency (APUE) and Physiological P use efficiency (PPUE). The results indicate that phosphate fertilizers and manure applications are essential to improve maize yield and nutrient P use efficiency.