Miracle-dz/UniFAR-FTUs huggingface dataset:
Experimental Analysis of SOFC Fuelled by Ammonia

In this study, ammonia is presented as a feasible fuel for solid oxide fuel cells (SOFCs). Ammonia has several interesting features as fuel due to low‐production cost, high‐energy density and, focusing on fuel cells and hydrogen application, ammonia is an excellent H2 carrier thanks to high value of volumetric and gravimetric densities. The paper reports experimental test performed to evaluate the feasibility of NH3 directly fed to a 50 cm2 single cell SOFC. A test plan was developed to compare pure ammonia with an equivalent mix of ammonia, nitrogen, and hydrogen and the study of temperature and voltage values strongly indicates that a two stage oxidation of ammonia can be predicted and a previous cracking reaction occurs in the cell due to the nickel catalytic contribution. The study of temperatures and of heat flows show how the cell is cooled down to lower temperature because of heat adsorbed by the reaction and by flow mix entering the anode. The study shows also how for operative temperatures below 800 °C the cracking reaction takes place in the cell active area. Efficiency test demonstrates that the cell can operate at 300 mW cm–2 and 30% efficiency based on ammonia LHV.
Análise microbiológica e caracterização eletroforética do queijo mussarela elaborado a partir de leite de búfala

This study evaluated the microbiological quality of mozzarella cheese made from buffalo milk obtained from retail outlets and validated their authenticity by checking the product for the possible presence of cow milk. The microbiological analysis included counts of E. coli, total coliform, positive coagulase Staphylococcus, and Salmonella spp. For the determination of mozzarella purity, we used polyacrylamide gel electrophoresis. Based on the results of the microbiological evaluation, we can state that 98% of samples comply with the legal microbiological standards although some have shown high values of total coliforms, which indicates poor hygienic conditions during manufacturing. However, 2% of the samples showed fecal coliform populations exceed the legal limit due to high E. coli contamination. Electrophoresis detected cow milk in 22% of the samples, which was probably added intentionally.
Mechanisms of contact charging and charge accumulation: experiments on soda glass

Charge transfer almost almost always occurs when a metal touches an insulator. In general, repeated contact to the same place will transfer additional charge (charge accumulation). In many materials charge accumulation is clearly related to conduction. It is usually supposed that charge accumulation occurs because the charge deposited by the contact diminishes by some conduction process, and the surface states emptied of charge can be refilled on the next contact. The author describes a series of experiments which indicate that this is not the mechanism of charge accumulation in soda glass. He concludes from his observations that conduction influences charge accumulation because it modifies the interfacial electric field between the glass and the contacting metal; the amount of charge transfer is controlled by this interfacial field rather than by the number of accessible states.
Foxing on Paper: A Literature Review

Abstract There has been a large amount of research published on foxing formation. This paper reviews selected literature published between 1930 and 2003 to show the progression of the research approach on this subject and to suggest areas for further discussion and research. Metals and microorganisms have been considered the main causes of foxing formation. Scanning electron microscopy and elemental analysis for inorganic and organic compounds were the main tools for finding the presence of metals and/or microorganisms in foxing spots. Newer research has focused on the condition of the affected paper itself by measuring the amount of free radicals and different functional groups formed by oxidation or acid hydrolysis. Certain foxing spots were found not to be associated with the presumed causes, i.e. metals or microorganisms. As a result, new hypotheses have developed on foxing formation including preferential cellulose oxidation or moisture condensation related to the non-homogeneity of the paper. Suggested treatment methods for foxing removal have included: mechanically removing metal inclusions and fungal spores, aqueous washing, oxidizing or reducing bleaching, chelating metals and enzyme treatment.
Flow and reaction in solid oxide fuel cells

A fuel cell is an electrochemical device that converts chemical energy into electrical energy. The essential difference between a fuel cell and a battery is that the fuel and oxidant are continually supplied to a fuel cell whereas a battery has a finite amount of fuel stored within it which eventually becomes exhausted, after which the battery has to be recharged or replaced. We consider here a tubular cell which is run on methane. A mathematical model for the reaction and transport processes in the cell is presented. This takes into account diffusion, advection and reaction as well as the electrochemical flow of oxygen. When the device is running steadily, we perform an analysis, using the method of matched asymptotic expansions to find the flow field, the mass fractions of each chemical species and the electrical power output. These results are confirmed by a numerical technique and compared with experimental results.
Characteristic regimes of premixed gas combustion in high-porosity micro-fibrous porous media

Dynamical behaviour of the premixed flame propagating in the inert high-porosity micro-fibrous porous media has been studied numerically. Effects of mixture filtration velocity, equivalence ratio and burner transverse size on the flame structure have been investigated and the regions of existence of different combustion regimes have been determined. It was found that the influence of the hydrodynamic instability on the flame dynamics is significant in the case of the moderate and high filtration velocities and this effect is negligible at the low velocities. At the moderate filtration velocities the effect of hydrodynamic instability manifests in the flame front deformation and in particular in the flame inclination. It was found that the flame can be stabilized within the whole interval of the filtration gas velocity, whereas in the ordinary porous media the standing wave is settled only at fixed value of gas filtration velocity. This finding is in line with recent experimental results on combustion in micro-fibrous porous media (Yang et al., Combust. Sci. Tech. 181 (2009), 1–16). Possible physical interpretation of the flame anchoring effect may be given on the base of present numerical analysis. At the high filtration velocities the hydrodynamic instability manifests itself in periodical appearance of the moving wrinkles on the flame front surface which forms non stationary high temperature trailing spots behind the leading part of the flame front. Such dynamics may be associated with splitting wave structures which were revealed in previous experiments (Yang et al., Combust. Sci. Tech. 181 (2009), 1–16).
Centers at junction boundaries in AlGaAs single heterojunction red light‐emitting diodes

In AlGaAs red light‐emitting diodes fabricated by liquid‐phase epitaxy the presence and characteristics of deep centers located near the injecting‐active junction boundaries have been studied. Transient capacitance, DLTS, photocapacitance, and photocurrent techniques have been applied. Besides the presence, in the n‐type injecting layer, of centers related to the Te dopant (DX defects), deep hole traps have been detected at both sides of the n‐p heterojunction. The physical origin of such hole traps, present in moderately large concentrations, is discussed in terms of Zn‐related complexes. This defect pattern allows us to explain the thermal‐ and photocapacitance, and the freeze‐out and photocurrent characteristics found in such devices.
Multi-particle sampling in Monte Carlo simulations on fluids: efficiency and extended implementations

Various technical aspects affecting the efficiency of a recently proposed novel Monte Carlo (MC) simulation scheme based on biased simultaneous displacements/rotations of all particles of the system are investigated using two polarisable models of water, the Chialvo–Cummings and Brodholt–Sampoli–Vallauri models, as a test case. Necessary expressions for polarisable site–site interaction models are derived along with a novel smoothing of the potential at the cut-off distance. In addition to the common thermodynamic and structural properties, the mean-squared displacements, rotation relaxation, speed of equilibration (translational order parameter, TOP) and autocorrelation coefficients have been computed as well, in order to assess the efficiency of the method. Gain in speed by parallelisation has also been examined. Performance of the method is coumpared with both the standard one-particle move method and the available approximate methods. It is shown that the multi-particle move (MPM) method performs about by a factor of 10 faster for the systems considered when compared with the common MC scheme, and several times faster when compared with the approximate methods. Parallelised codes of the MPM method may then perform about 70 times faster than the conventional MC. These conclusions hold true for the system size simulated (N = 256) because the efficiency of the multi-particle method depends on the size of the system: its efficiency even increases with increasing number of particles.
Single-Molecule Detection in Capillary Electrophoresis: Molecular Shot Noise as a Fundamental Limit to Chemical Analysis

Capillary electrophoresis is coupled with a single molecule detector based on laser-induced fluorescence. Individual molecules migrating from the capillary are detected and counted with 50% efficiency. Injection of 30 000 analyte molecules generates a reproducible peak consisting of at least five components. However, injection of 3000 or fewer molecules leads to a noisy and irreproducible peak. Monte Carlo simulation demonstrates that this irreproducibility results from molecular shot noise or stochastic fluctuations in the number of injected molecules. The model predicts that the relative standard deviations of peak area, peak center, and peak width are inversely proportional to the square root of the number of injected molecules. At least 104 analyte molecules (17 zmol) are required to define peak area and width with 1% relative precision. Fluctuation in the number of molecules taken for chemical analysis is a fundamental and irreducible source of uncertainty.
Factors affecting potato petiole sap nitrate tests

Abstract Many factors can affect the nitrate‐nitrogen concentration of potato petioles. They include but are not limited to the following: N‐fertilizer applications, mineralizable soil N, time of sampling, position of the petiole on the plant, age of the plant, potato cultivar, time of the day when plants are sampled, and the environmental conditions prior to sampling. A better understanding of these factors should lead to an improved sap test. Five irrigated potato studies were conducted between 1991 and 1993 to evaluate this variability. Sap nitrate‐N concentration was found to be closely associated with N‐fertilizer rates and soil mineralizable N. Sap nitrate levels were usually highest early in the season and declined with the age of the plant. The decline with time can be interrupted or delayed by in‐season N applications. Although the sap nitrate level among six different cultivars and diurnal sampling periods was found to be statistically significant, the differences were relatively small. By caref.
Significant precision in crystal structural details. Holly Springs hydroxyapatite

The degree to which physically significant precision in crystal-structural details can be obtained with selected routine procedures has been assessed and some illustrative applications to analyses of bonding effects and of impurity substitutions have been made. Least-squares refinements with X-ray data for three single crystals of mineral hydroxyapatite and with neutron diffraction data for a fourth of the same origin yielded R = 2% in each case (_> 40 parameters adjusted and > 500 reflections). Seemingly minor extinction corrections improved the mutual agreement among separate measures of some parameters from 4a to the final la (typically <5%) found for all, even anisotropic thermal, parameters in the X-ray cases. Final results were insensitive to reasonable changes in the weighting scheme. Comparisons of X-ray and neutron results, which generally agreed within 2~r, showed systematic differences associated with the oxygen atoms bonded to phosphorus in the phosphate group. Analysis of the final R-value also suggested (1) real differences, among the crystals, smaller than the o-'s associated with individual parameters and (2) either a systematic inadequacy of the refinement model, or similar residual systematic errors (such as thermal diffuse scattering contributions), in both neutron and X-ray data. Direct refinement for the degree of fluorine substitution for OH in Cal0(PO4)6(OH)2 led to the same result, 8 at. % substitution, with both X-ray and neutron data. Analysis of the decrements found with both X-ray and neutron data in the apparent site-occupancy factors for the Ca atoms showed that a simple substitution of Mg2+ for Ca 2÷ at the same site is not in itself a sufficient substitutional model for this case.
Composition of the Essential Oil of Lavender (Lavandula angustifolia Mill.) from Lithuania

abstract The essential oil of lavender flowering parts and stems was analyzed by capillary GC and GC/MS. Sixty-six constituents were identified, which constituted 92.1% of the total integrated area of the detected GC peaks. The concentration of the linalool in the flowering parts was 5372.4 mg/kg, that of linalyl acetate 5121.7 mg/kg, that constituted 22.0% and 26.5% respectively in the total oil. The oil content in the stems was more than 30 times lower than in the flowering parts.
Separation of radiated sound field components from waves scattered by a source under non-anechoic conditions.

A method of estimating the sound field radiated by a source under non-anechoic conditions has been examined. The method uses near field acoustic holography based on a combination of pressure and particle velocity measurements in a plane near the source for separating outgoing and ingoing wave components. The outgoing part of the sound field is composed of both radiated and scattered waves. The method compensates for the scattered components of the outgoing field on the basis of the boundary condition of the problem, exploiting the fact that the sound field is reconstructed very close to the source. Thus the radiated free-field component is estimated simultaneously with solving the inverse problem of reconstructing the sound field near the source. The method is particularly suited to cases in which the overall contribution of reflected sound in the measurement plane is significant.
Synthesis and Characterization of Azobenzene–Porphyrins

A new series of novel covalently connected meso-tetrakis(3-azophenyl-4-hydroxy-5-methoxyphenyl)porphyrins were synthesized by linking azobenzene unit at the meta-position of the meso-phenyl group. These are characterized by UV–vis, IR, 1H-NMR, CHN, and FABMS spectroscopic techniques. All the porphyrin compounds showed a typical high energy Soret band at around 435 nm and azobenzene absorption at around 350 nm in UV–vis spectra. Fluorescence intensity of meso-tetrakis(3-(4-methoxyazophenyl)-4-hydroxy-5-methoxyphenyl)porphyrin (2c) has been observed to be maximum compared with other azobenzene porphyrins.
Nitrogen fertiliser source effects on the growth and mineral nutrition of pepper (Capsicum annuum L.) and wheat (Triticum aestivum L.)

BACKGROUND: The presence of stable mixed nitrogen forms (such as nitrate/ammonium/urea or nitrate/urea) in the soil solution is due to the use of nitrification and/or urease inhibitors in urea-based fertilisers. However, there is no specific information in the literature comparing the efficiency of these urea mixed nitrogen forms as a nitrogen source for plants with that of nitrate and ammonium/nitrate. The aim of this study was to compare the effects on plant growth and mineral nutrition of different nitrogen forms, including mixed nitrogen forms containing urea. RESULTS: The results indicated that for both wheat (Triticum aestivum L.) and pepper (Capsicum annuum L.) the growth of plants fed mixed nitrogen forms containing urea was generally similar to that of plants receiving nitrate and nitrate/ammonium. Only in the case of pepper did ammonium/urea nutrition cause a significant decrease in plant growth. The presence of nitrate corrected the negative effects of mixed nitrogen forms containing ammonium and/or urea on the growth of pepper plants. CONCLUSION: Mixed nitrogen forms containing urea did not cause any negative effect on plant growth or mineral nutrition. In fact, plants fed mixed nitrogen forms containing urea had higher shoot concentrations of potassium, phosphorus, iron and boron than plants receiving nitrate. Copyright © 2007 Society of Chemical Industry
Relações entre uso do solo, relevo e fertilidade do solo em escala de microbacia

Productivity in subsistence agricultural systems relies on natural soil fertility levels. Under strongly undulated relief conditions, it is expected that soil fertility will be determined not only by land use, but also by the position in the landscape. To study these relationships 260 single soil samples (0-20 cm) from the Vaca Brava watershed, Paraiba, representing combinations of three land uses, five positions in the landscape and five textures were analyzed for extractable P, exchangeable bases and soil acidity. Ca and Mg comprised 75-80% of exchangeable cations, K and Na between 10 and 15% and H+Al 10%. The average pH was 5.5, while extractable P (Mehlich-1) averaged 3.8 mg kg-1 soil. Although land use, relief and texture exerted significant effects (p < 0.05) upon certain nutrient concentrations, in a broad sense the watershed appeared relatively uniform. The main effect of land use resulted from the use of animal manure in areas of subsistence agriculture and fodder, which were preferentially located at the base of stopes and low lands positions. Approximately 80% of the samples were low in extractable P, while 70% had medium levels of extractable K. However, when available K was estimated by the K/(Ca+Mg)0,5 ratio, most samples were classified as low.
Correlation of Elongational Fluid Properties to Fiber Diameter in Electrospinning of Softwood Kraft Lignin Solutions

Viscoelastic properties of N,N-dimethylformamide (DMF) solutions of softwood kraft lignin (SKL) containing small amounts of poly(ethylene oxide) (PEO) were investigated. Of interest is the relationship between viscoelastic properties of the spinning solutions and their corresponding electrospinning behavior. Although it is well established that fiber diameter is critical in determining the material properties of nanofibers, lignin solutions have been observed to display poor electrospinnability in many instances. Thus, the motivation behind this work was to understand and exert control over the relevant fluid properties that control the fiber diameter of SKL/PEO fibers, The results of dynamic shear and capillary breakup extensional rheometry (CaBER) experiments indicated that SKL solutions were weakly elastic in shear and Newtonian in elongational flow. SKL solutions were not electrospinnable at concentrations of 25–45 wt % but form fibers at 50 wt % concentration. The addition of PEO to SKL solutions led.
Influência da adubação orgânica no crescimento de tangerineira cv Clemenules e nos atributos químicos e microbiológicos do solo

In order to evaluate the effect of different organic fertilization strategies, as nitrogen source, on vegetative growth of young citrus plants as well as on chemical and microbiological soil properties, a two-year experiment was performed on eighteen months old citrus plants (cv Clemenules) grafted on Poncirus trifoliata. The trees were transplanted in 35 L pots filled with a sandy-loam soil and drip irrigation. The following treatments were compared: Control (unfertilized); Mineral fertilizer (MF); Vermicompost (VC); Vermicompost + blood meal (VC + BM); Citrus compost (CC). Each treatment was applied to 6 plants (replicates). At the end of each vegetative season the following parameters were measured: rootstock section area, plant height, leaf and shoot number per plant, leaf fresh and dry matter. Three plants per treatment were harvested and leaf total area, branches and roots (divided in fine and coarse) fresh and dry matter were recorded. In addition, soil samples of each pot were collected and soil chemical and microbiological properties were measured. Plant growth was positively affected by VC + BM fertilization strategy in comparison to the other treatments. Such effect was observed despite the total amount of N supplied to VC + BM, was about 40% lower than the N applied to plants by mineral source MF. The supply of blood meal contributed to avoid the temporary soil N-deficiency occurred when organic fertilizer is incorporated into the soil. VC and CC strategies induced limited effects on plant growth likely due to the lower soil N-availability than the plant requirements. Moreover, only VC + SB promoted soil total N and microbial soil respiration. Generally, the macronutrient concentration in the leaves was adequate in relation to P, K, Ca and Mg, except for N, giving evidence of the high request for N at the beginning of growing and development stage of Clemenules tangerines.
Indications & Complications of Colostomy in Children

Objectives: To evaluate colostomy indications and associated complications as well as management of their complications. Design: Descriptive Study. Place: Children Hospital Quetta. Period: From March, 2013 to March, 2016. Methodology: This is a descriptive study of indications complications and their managements of all the patients admitted in Children Hospital for colostomy. The patients who were operated upon previously were excluded from the study. Results: Total number of the patients in which colostomy was done were 80. Colostomy complications occurred in 52 patients (65%). Most common complication was skin excoriation in 24 patients (30%), prolapsed in 12 patients (15%), burst abdomen in 2 patients (2.5%), per colostomy hernia in 1 patient (1.25%), 1 patient died due to multiple anomalies (1.25%). Conclusions: Adequate pre-operative counseling of parents, good stoma care and early stoma closure gives good results in our setup.
EFFECT OF DIFFERENT PASTEURIZATION CONDITIONS ON ENZYME INACTIVATION OF ORANGE JUICE IN PILOT‐SCALE EXPERIMENTS

The orange juice pasteurization is associated with enzymatic degradation (primarily pectin-methylesterase) of soluble pectin. Time-temperature curves were established to study different pasteurization conditions on enzyme inactivation, for fresh single-strength orange juice from Florida, containing natural PME enzyme. The orange juice was heated in a DeLaval, model P5-VRB plate heat exchanger with heating and cooling sections, and a 0.0101 m 3 volume holding tube. The temperature in the heat exchanger was controlled by means of a pneumatic proportional controller. The residence time in the holding tube of the heat exchanger was monitored by adjusting the flow rate of the positive feed pump. The calculated holding times to obtain 90% reduction of enzyme activity ranged from 33.27 s at 80C to 17.85 s at 90C.