Miracle-dz/UniFAR-FTUs huggingface dataset:
The Influence of the Recirculation Region: A Comparison of the Convective Heat Transfer Downstream of a Backward-Facing Step and Behind a Jet in a Cross Flow

Convective heat transfer is examined in two typical examples of separated flows, namely: the flow over a backward-facing step and a two-dimensional jet entering a cross flow. Local Nusselt numbers were determined in and behind the recirculation region. The main parameters influencing the heat transfer, the Reynolds number and the momentum flux ratio of the jet and the cross flow, have been varied in a wide range. In addition to heat transfer measurements, the flow field has been documented using a LDA-system and oil film techniques. The static pressure distribution at the wall within the separated flow is also given. The measurements are compared with the results of a numerical code, based on a finite volume method, where the well known k-e-model is employed. The differences in Nusselt numbers predicted with a one- and a two-layer model are shown to demonstrate the influence of wall functions on heat transfer. The numerical and experimental results are compared with available data, and the differences and similarities in the heat transfer behaviour of separated flows are discussed.Copyright © 1989 by ASME
Ozone oxidation of biological sludge: Effects on disintegration, anaerobic biodegradability, and filterability

This study deals with pretreatment of biological sludge by ozone oxidation for the purpose of biological sludge disintegration. Different ozone dose ranged between 0.005 and 0.25 gO3/g DS were used for the process optimization. The potential for improving anaerobic digestion through ozone oxidation was also investigated. In addition, the effect of ozone oxidation on filterability characteristics of sludge was evaluated using lab‐scale experiments. The results showed that ozone effectively disintegrates the sludge. The highest disintegration degree (51.1%) was achieved when 0.1gO3/g DS was used. Biochemical methane potential (BMP) results suggest that ozone oxidation significantly enhanced the biodegradability of biological sludge. For 0.1 gO3/g DS, 25% higher methane production was achieved compared with raw sludge. The supernatant characteristics of the sludge were also affected by ozone oxidation. For 0.1 gO3/g DS, the soluble chemical oxygen demand (SCOD), dissolved organic carbon (DOC), total nitrogen (TN), and total phosphorus (TP) increased by 300%, 94.2%, 225%, and 200%, respectively. Finally, using ozone oxidation for the purpose of floc disintegration (0.1 gO3/g DS) had no negative effect on sludge filterability in terms of CST results. But at higher doses than 0.1 gO3/g DS, ozone oxidation reduced the filterability of sludge. © 2010 American Institute of Chemical Engineers Environ Prog, 2011
An Analysis of TDT and Arrhenius Methods for Handling Process and Kinetic Data

Thermal process calculations generally involve first order reaction kinetics which have been commonly described by the thermal death time (TDT) method in the field of food science but would normally be evaluated by the more conventional Arrhenius approach in most other fields. The relationship between these two irreconcilable approaches is examined conceptually and mathematically in terms of temperature dependence and their use for process time predictions. The errors associated with interconversion of Ea and z were shown to be functions of both selected reference temperature and the temperature range used. Good conversions of literature data with minimum error were obtained by substituting the limits of the experimental range over which kinetic data were obtained for Tmin and Tmax in the relationship: Ea= 2.303 TminTmax/z. Although there is no perfect solution to these two conceptually different approaches to handling kinetic data and no proof as to which one is better, the approach of using the experimental temperature range limits produces good results.
Phenolic content and ascorbic acid are major contributors to antioxidant capacity of fruits and vegetables commonly consumed in Turkey

A large body of evidence has shown that the regular consumption of fruits and vegetables provides major health benefits and prevents degenerative processes attributed to their various antioxidant components. Therefore, in this study, antioxidant capacity, total phenolic content, phenolic acids, ascorbic acid and s-carotene of commonly consumed vegetables (tomato, carrot, cauliflower, leek, cabbage) and fruits (strawberry, cherry, apricot, peach, pomegranate, pear, orange, apple) in Turkey were measured. Antioxidant capacity was measured by Trolox equivalent antioxidant capacity method (TEAC), total phenolic content by Folin-Ciocalteu method and ascorbic acid, s-carotene and phenolic acid profile by high performance liquid chromatography (HPLC). The results indicated that, total antioxidant capacity varied in fruits (223.33±6.47 - 2351.46±158.64 µmol/100 g) and vegetables (184.27±11.82 - 685.90±0.73 µmol/100 g). Antioxidant capacity is approximately three times higher in fruits (cherry > peach > strawberry > apricot > orange > apple (golden) > apple (starking) > pomegranate > pear) than in vegetables (cabbage (red) > leek > cabbage (white) > cauliflower > carrot > tomato). Also total phenolic content (TPC) of vegetables and fruits varied between 20.30±3.03 - 255.46±15.20 mg GAE/100 g fresh weight and 155.60±5.09 - 375.87±13.38 mg GAE/100 g fresh weight, respectively. Total phenolic content and phenolic acids were higher in fruits than vegetables. Orange, strawberry, cabbage and cauliflower had the highest ascorbic acid content, whereas s-carotene existed only in carrot, apricot, and peach. Contribution of phenolic content to total antioxidant capacity was higher in fruits than in vegetables whereas contribution of ascorbic acid was vice versa. Phenolic content and ascorbic acid of the examined vegetables and fruits consumed in Turkey have significant contribution to the total antioxidant capacity.
Using a Progressive Paper to Develop Students' Writing Skills.

This article describes the use of a progressive paper in a capstone course to develop students’ writing skills. A progressive paper is one that students write one section at a time: as they add each new section, they go back and revise the previous parts based on actionable feedback from the instructor. In this course, the progressive paper takes the form of a laboratory report for a multistep synthesis. Students revise and update this paper throughout the semester. Each revision coincides with an additional step in the synthesis. This results in a complete journal-style article at the end of the semester. The students in this course show significant improvement in their writing skills throughout this process.
Models for Colloidal Aggregation

Computer simulations have been used for more than a quarter of a century to develop a better understanding of non equilibrium growth and aggrega­ tion processes. Important early examples include VoId's ballistic deposi­ tion model for aggregation and sedimentation (1, 2), Sutherland's ballistic cluster-cluster aggregation model for floc formation (3), and Eden's surface growth model for the generation of cell colonies (4). Because of limited computer resources these early simulations were carried out on a small scale using simple models. Since these early pioneering efforts computer speed, storage capabilities, and availability have increased enormously and the task of writing computer programs has become much easier and more reliable. These developments have allowed two almost divergent research directions to develop. On the one hand, models have been developed that incorporate as much as possible of what is known about the physics and chemistry of aggregation processes, and on the other hand, a variety of very simple models have been introduced that allow us to generate the very large structures needed to investigate asymptotic (large size limit) geometric scaling relationships. The exploration of very simple aggregation models has been stimulated by the realization (5-10) that real aggregation processes and simple aggregation models frequently lead to structures that can be described in terms of the concepts of fractal geometry (11). In particular, the recent interest in nonequilibrium growth and aggregation models was initiated by the discovery by Witten & Sander (6) that a simple diffusion-limited aggregation (DLA) model in which particles are added, one at a time, to a growing cluster or aggregate of particles leads to
A comparative investigation of carbon black (Super-P) and vapor-grown carbon fibers (VGCFs) as conductive additives for lithium-ion battery cathodes

To investigate the synergistic effect of different types of conductive additives on the cathode performance of lithium-ion batteries, various types of cathode materials containing different ratios of vapor-grown carbon fibers (VGCFs) and carbon black (Super-P) are investigated. The pillar-like morphology of the VGCFs enabled them to efficiently connect to the active materials and hence, the highest electrical conductivity of LiCoO2 and LiFePO4 (both of which are composed of primary particles) was achieved with the VGCFs. On the other hand, for LiNi0.6Co0. 2Mn0.2O2, composed of micro-sized secondary particles embedded with nano-sized primary particles, improved electrical conductivity was achieved with a mixture of VGCF and Super-P via synergistic action.
PROTECTIVE EFFECT OF SEMECARPUS ANACARDIUM NUT EXTRACT AGAINST HYPERAMMONEMIA IN RATS

This investigation was designed to determine the possible protective effect of Semecarpus anacardium nut milk extract (SA) against ammonium chloride (NH4Cl)- induced hyperammonemia. Experimental hyperammonemia was induced in adult male Wistar rats (180-200 g) by intraperitoneal injections of NH4Cl (100 mg/kg body weight) thrice a week. Rats were treated with SA (150 mg/kg body weight) via oral administration. At the end of experiment al duration, blood ammonia, plasma urea, serum liver marker enzymes and lipid peroxidation in plasma and tissues (liver and brain) of normal and experimental animals were analyzed. The results revealed that NH4Cl -induced hyperammonemia, as evidenced by increases in the levels of blood ammonia, plasma urea, lipid peroxidations such as thiobarbituri c acid reactive substances (TBARS), hydroperoxides (HP) and activities of liver markers (alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) and the activities of glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase and reduced glutathione (GSH), were decreased in liver and brain tissues of NH4Cl group compared with the normal group. On the other hand, SA treatment reversed all these biochemical indices. The study shows wider evidence for the antihyperammonemic, hepatoprotective, neuroprotectiv e and antioxidant activities of SA extract against NH4Cl -induced hyperammonemia.
The use of gel-stabilized gradient plates to map the responses of microorganisms to three or four environmental factors varied simultaneously

The Szybalski wedge plate technique has been used to map the responses of bacteria to up to 4 simultaneously varying environmental factors. 2-dimensional NaCl-pH gradient plates were used throughout. Sets of the latter were incubated at a range of temperatures to provide a third dimension. A fourth variable, nitrate concentration, was investigated by incorporating it homogeneously in sets of NaCl-pH gradient plates.
Evaluation of Calcium and Phosphorus Release Pattern and Composition of Bulk- blended NPK 20:10:10 Fertilizer formulated using Ogun Phosphate rock as the P source.

Experiment was conducted in the laboratory at the University of Agriculture, Abeokuta, Southwest Nigeria to evaluate the composition and nutrient release pattern of bulk-blended NPK 20:10:10 fertilizer formulated using Ogun phosphate rock as the P source. The grade, stability and incubation studies on the Gateway fertilizer compared to a Standard fertilizer were carried out in the laboratory. The release pattern of phosphorus in the bulk-blended product was determined by an incubation study in the laboratory. 250g of soil was mixed with 50g fertilizer, moistened with distilled water to field capacity, and incubated in a sealed polythene bag for a period of four months. The soil was thoroughly mixed with the fertilizers (Standard and Gateway) and sampled every two weeks for analysis of available P, exchangeable Ca 2+ and pH. The two fertilizers were compared using two soil series namely; Agege (Arenic tropudalt) and Iwo (Kandic palenstalf). Laboratory analysis showed that the grade of the Gateway fertilizer was 10:5:7 and the Standard 12:9:6. Stability study after four months revealed that P content decreased by 34.0 and 41.1 %, respectively in Gateway and the Standard fertilizers. Incubation with soil for 14 weeks led to 48.6 and 68.5 % P decrease, respectively in Gateway and Standard fertilizer. However, Ca content increased with incubation while changes in pH were inconsistent. It is important to note that highest P values were recorded for the two fertilizers under Agege soil series than Iwo series. It was concluded therefore that Gateway fertilizer will benefit acid soils but the nutrient content should be improved upon to meet the stated analysis on the bag.
Analysis of volatile composition of honey by solid phase microextraction and gas chromatography-mass spectrometry

Honey aroma is largely dependent on its volatile fraction, which in turn is influenced by nectar composition and by possible modifications after harvesting. Solid phase microextraction (SPME) allows a simple and rapid fractionation of volatile compounds in honey as a prior step to their GC-MS qualitative and quantitative determination. A simple SPME-based procedure has been developed for GC-MS analysis of honey volatiles and applied to the study of 6 different commercial honeys. The possibility of honey characterization from the analytical data obtained by the SPME method is discussed.
βα-BIFURCATION OF GROWTH DURING THE SPHERULITIC CRYSTALLIZATION OF POLYPROPYLENE

Spontaneous β to α polymorphic transition occurs from pinpoint nuclei on the periphery of the growing β-spherulite of polypropylene at a high crystallisation temperature (βα-bifurcation of growth), and its relative occurrence frequency increased with rising temperature. This is accompanied by a simultaneous decrease in growth rate. The phenomenon of βα-bifurcation of growth was interpreted through secondary βα-nucleation and the necessary energetic conditions and temperature dependence of this have been discussed.
Influence of temperature, soil moisture and soil characteristics on the persistence of alachlor

Alachlor degradation in soils followed first-order reaction kinetics. Half-lives in moist soil varied from 11.30 to 34.8 days at 25°C to 95.9 to 279.6 days at 5°C, and at 15°C varied from 15.7 to 83.1 days at 5 kPa soil water stress (field capacity) to 82.8 to 281.4 days at 1500 kPa (permanent wilting point). Degradation rates in laboratory incubations with fluctuating temperatures were predicted with reasonable accuracy from the constant-temperature data. The degradation rate and extent of adsorption were lower in subsoils than in soils from the plough layer. Degradation rate was positively correlated with microbial biomass and microbial respiration, and adsorption was positively correlated with soil organic matter content. Persistence of alachtor in field plots was correlated well with variations in weather pattern during the period September 1990 to July 1991, with an effective half-life varying from 20 to 60 days. Persistence in the field plots was predicted accurately by a computer model of herbicide behaviour.
The Response Surface Methodology as a tool to optimize the extraction and acid hydrolysis processes applied to babassu residues

The new approach used to find extractives, holocellulose and total lignin from typical Brazilian biomass residues was optimized through the Response Surface Methodology (RSM) in the present study. The effects of different reaction conditions, including the hydrolysis reaction and extraction time, as well as the alcohol substrate molar ratio were investigated. A quadratic polynomial regression model was used to analyze the experimental data. The coefficient of determination was higher than 0.85 and the model was considered to be adequate. The obtained data showed that the methodologies by the National Renewable Energy Laboratory must meet each biomass type. These data can be now applied to large-scale biomass fuel production using the optimized results.
Solvent characterization using the dispersion number

Abstract When developing new solvent extraction processes, one often has to evaluate new solvents, new aqueous phases, or both for their ability to work in plant-scale equipment. To facilitate solvent characterization, a simple test is proposed based on the dimensionless dispersion number (NDi). It allows one to characterize the ability of the solvent to separate from a two-phase dispersion and to estimate process throughput for equipment of a given size. Several ways to carry out the NDi test are given, including a standard test procedure. The NDi test was applied to the performance of solvent extraction equipment with discrete process stages, the leaching of plasticizers from plastic tubing, and the development of a new solvent for the combined extraction of strontium and transuranic elements.
Impact of excreted nitrogen by grazing cattle on nitrate leaching

At De Marke experimental farm, data on water and nitrogen flows in the unsaturated zone were gathered on two grazed pastures on sandy soils during the years 1991 to 1994. These provided a basis for calibration and validation ofsimulation models.The different levels of nitrate-N concentrations ofthe two plots could largely be explained by differences in crop uptake and simulated denitrification as influenced by different groundwater levels. The irregular distribution of excreta was taken into account by a simulation study quantifying the variability of nitrate-N concentrations under a grazed fi eld. The resulting distribution of simulated nitrate-N concentrations explained the average and peak values of the measured concentrations. Temporal variability of weather was used to assess the nitrate leaching risk under urine patches deposited in either July or September. At site A the probability of exceeding the EC-directive by drinking water (11.3 mg/l nitrate-N) under a urination deposited in either July or September was respectively 10 and 25%. The average field concentration at this site will hardly ever be a high risk for the environment under the current farm management. At site B the EC-directive will be exceeded under any urine patch in almost 100% of the years, affecting the field average concentration. In field B careful grazing management would result in less nitrate leaching, but the environmental goals would not be reached.
Drip irrigation for application of potassium to tart cherry 1

Abstract Fertilization of fruit crops through drip irrigation is an efficient method of meeting the crop's nutritional needs, though cumulative effects or interactions with native minerals may be pronounced in the restricted zone of application. Sources of potassium (K) for tart cherries have not been previously compared for their effects on tree performance and possible interaction with other nutrients under conditions of drip application in an orchard. Our objective was to evaluate these factors by drip application of four rates (0, 0.35, 0.7, and 1.4 kg K2O per tree) of three sources (KCl, KNO3, and K2SO4) of K to tart cherry trees during three consecutive growing seasons. Application of non‐Cl sources of K by this method maintained foliar K within the sufficiency range and increased fruit yield in one year of the study, but had no effect on fruit size or quality. Maximum fruit yield was obtained at 1.5–2.0% foliar K. Application of non‐Cl sources suppressed uptake of calcium (Ca) and magnesium (Mg) in.
Molecular simulation of phase coexistence in adsorption in porous solids

In this work a recently proposed method, the gauge-cell Gibbs ensemble Monte Carlo, is extended to deal with polar substances. The behaviour of water, a hydrogen bonding, weakly adsorbing fluid, is compared with that of methane, a strongly adsorbing, non-polar fluid, in the vicinity of the phase transition. The mechanisms of condensation for the two species are seen to be significantly different in nature. A systematic study of the effect of the pore width on the phase equilibrium of water is also performed. Our results show that the narrowing of the pore shifts the equilibrium transition pressure to lower values and reduces the extent of vapour metastability, but exerts little influence on the stability of the liquid phase.
ARSENITE SORPTION AND DESORPTION IN SOILS

A linear form of the Freundlich isotherm was used to describe arsenite [As(III)] sorption by the A and B horizons of five West Virginia soils. Arsenite sorption conformed to the Freundlich isotherm over the entire concentration range for all the soils. Simple correlation coefficients and multiple regression equations were used to relate soil properties to parameters of the Freundlich equation. Iron oxide percentage and pH were the soil properties most closely related to parameters of As(III) sorption. The rate of As(III) sorption by the A and B horizons of an Upshur soil was rapid initially and decreased with time. A modified form of the Freundlich equation was used to explain the As(III) sorption rate data. Arsenite sorption was not reversible; only a small amount of the sorbed As(III) was released after five desorption steps. The modified Freundlich equation was also used to describe As(III) desorption rate. Simple and multiple regression calculations indicated that iron oxides and pH were correlated with the rate of As(III) desorption by the investigated soils. Additional Index Words: Freundlich isotherm, rate equation. View complete article To view this complete article, insert Disc 4 then click button8
Microbially enhanced oil recovery from unconsolidated limestone cores

Abstract The enhanced recovery of residual oil from unconsolidated carbonate cores using microorganisms was examined in model cores packed with chips of Viola limestone. Vibrio aspartigenicus strain GSP‐1, an acid producer, and Bacillus licheniformis strain JF‐2, a surfactant producer, were used as the test microorganisms. The primary hypothesis tested was that microbial treatment of a packed core system would result in the recovery of residual oil from the carbonate test system. After three treatments, 39–44% of the residual oil‐in‐place was recovered from packed core systems after treatment with strain GSP‐1. Two treatments with strain JF‐2 resulted in a 27% recovery of the residual oil‐in‐place. Modification of the core matrix was indicated by the presence of calcium in the core effluents and significant amounts of carbonate fines found in the dissected cores, presumably caused by dissolution of the carbonate matrix by microbial acid end products of metabolism (microbial matrix acidizing). These result.