Mixtures Of Various Proportions Research Articles

SCIENTIFIC PRINCIPLES OF INCREASING THE EFFICIENT PERFORMANCE OF DIESELS WHEN USING BIOFUELS

The use of biological fuels based on vegetable oils and other similar raw materials in diesel engines in developed countries can reduce the cost of mineral diesel fuel and improve the environment. This issue is relevant for Ukraine as well, in connection with which the governing bodies pay great attention to it. The deepening of knowledge in the study of the peculiarities of the flow of operating cycles of diesel engines, their power and toxic characteristics at the same time contributes to the optimization of the use of these types of fuel. In this work, the main issues related to the use of vegetable oils, such as sunflower, rapeseed, corn oils and their ethyl esters, both in pure form and in a mixture with mineral diesel fuel, are considered as a biological component of fuel. Theoretical issues and experimental data related to the use of these fuels in diesel engines are considered. Experimental studies were carried out on diesel engines D21A and four-cylinder - Skoda - an analogue of the 1.9-liter Volkswagen engine with turbocharging. Economic and toxic characteristics were obtained by load and speed characteristics. There is an increase in the consumption of mixed fuel in comparison with mineral fuel, the toxic characteristics were better in some indicators, in some cases, for example, when operating at increased capacities, they worsened relative to those when operating on mineral fuel. The basic principles of the effective use of biofuels in transport diesel engines are formulated in terms of energy and toxic indicators, as well as the corrosive effect of blended biofuels on fuel equipment. Today, gas stations in Ukraine only sell alternative fuels for gasoline engines. These are mixtures in various proportions of gasoline and bioethanol with a content of the latter up to 35–40% by volume. The price of such fuel is lower than the price of gasoline. Biodiesel fuels are not commercially available, although they would also cost less than mineral diesel fuel. It is likely that the use of biodiesel fuels is restrained due to the need to adapt the diesel engine to these fuels and to monitor the state of the fuel equipment. However, these costs are small and can be easily compensated for by the difference in the price of mineral and biodiesel fuels. It can be assumed that, first of all, biodiesel will be introduced into agricultural machinery.

Reusable polymeric films for fluorometric Al3+ detection in anti-counterfeiting and security applications

The development of three types of hydrazide-derived polymeric probes for the selective fluorescent detection of Al3+ in aqueous media and their anti-counterfeiting and security applications are described herein. The detection of Al3+ among several metallic cations via formation of Al3+–ligand coordination complexes is successfully demonstrated. Upon addition of Al3+ ions to an aqueous solution of these polymers, complexes P1–Al3+, P2–Al3+, and P3–Al3+ are formed. They exhibit strong turn-on blue (λem ≈ 451 nm; Stokes shift =74 nm), green (λem ≈ 505 nm; Stokes shift =110 nm), and red (λem ≈ 597 nm; Stokes shift =137 nm) fluorescence emissions, respectively, via a metal chelation-enhanced fluorescence mechanism. Additionally, polymeric films obtained from the combination of P1, P2, and P3 mixtures in various proportions allow the observation of a full-color range of turn-on fluorescence in response to Al3+ ions. These polymeric films also display recyclability as processing with Fˉ caused their complexes with Al3+ to dissociate. Finally, the polymeric films are applied to the printing of anti-counterfeiting quick response (QR) codes on paper. These printed QR codes are expected to be used as concealed and recyclable anti-counterfeiting security tools.

Membrane Fouling Due to Protein-Polysaccharide Mixtures in Dead-End Ultrafiltration; the Effect of Permeation Flux on Fouling Resistance.

Significant gaps exist in our knowledge of ultrafiltration (UF) membrane fouling, due to mixtures of poly-saccharides and proteins, despite a fair amount of related research. To get new insights into fouling layer characteristics, experiments were performed under constant-flux, within the range of practical interest (15–90 L/m2h), with typical polysaccharides (sodium alginate, SA), proteins (bovine serum albumin, BSA) as well as their mixtures in various proportions (1:3, 1:1, 3:1), and total organic matter concentration of 30 mg/L. The feed-water salinity and calcium ion concentration were 2000 mg/L NaCl and 2 mM, respectively. The temporal evolution of such fouling layers on flat-sheet membranes was monitored by recording the trans-membrane pressure variation. The results show that the specific fouling resistance α is strongly affected by flux, and the fouling propensity of polysaccharide-protein mixtures is significantly enhanced compared to single foulants, i.e., when BSA and SA are alone. The fouling layers are compressible and their resistance α tends to increase with the mass ratio of alginate in the mixture, particularly at high fluxes. To quantify these effects, correlations are presented of the initial fouling resistance αi with permeate flux J and of the evolution of α. R&D priorities are suggested on this topic of mixed foulants.

Increasing Performance and Thermostability of D-Phenylglycine Aminotransferase in Miscible Organic Solvents.

BackgroundD-Phenylglycine aminotransferase (D-PhgAT) is highly beneficial in pharmaceutical biotechnology. Like many other enzymes, D-PhgAT suffers from low stability under harsh processing conditions, poor solubility of substrate, products and occasional microbial contamination. Incorporation of miscible organic solvents into the enzyme’s reaction is considered as a solution for these problems; however, native D-PhgAT is not significantly stable in such solvents.ObjectiveHalophiles are known to survive and withstand unsavory habitats owing to their proteome bios. In the current study, with an eye on further industrial applications, we examined the performance and thermostability of four halophilic peptides fused D-PhgAT variants in reaction mixtures of various proportions of different miscible organic solvents and various temperatures as well as desiccation.Materials and MethodsPlasmid constructs from the previous study (Two alpha helixes and loops between them from Halobacterium salinarum ferredoxin enzyme fused at N-terminus domain of D-PhgAT) expressed in Escherichia coli and then D-PhgAT purified. Purified proteins were subjected to various proportions of miscible organic solvents, different temperatures, and desiccation and then performance and thermostability monitored.ResultsStudy confirmed increased C50 of all halophilic fused D-PhgAT variants, where the highest C50 observed for ALAL-D-PhgAT (30.20±2.84 %V/V). Additionally, all halophilic fused variants showed higher thermostability than the wild-type D-PhgAT in the presence of different fractions of acetone, N,N-Dimethylformamide and isopropanol in aqueous binary media, while zero activity observed at the presence of methanol.ConclusionOur results suggest that applying this new technique could be invaluable for making enzymes durable in discordant industrial conditions.

Ionomic and metabolic responses to neutral salt or alkaline salt stresses in maize (Zea mays L.) seedlings

BackgroundSoil salinity and alkalinity present a serious threat to global agriculture. However, most of the studies have focused on neutral salt stress, and the information on the metabolic responses of plants to alkaline salt stress is limited. This investigation aimed at determining the influence of neutral salt and alkaline salt stresses on the content of metal elements and metabolites in maize plant tissues, by using mixtures of various proportions of NaCl, NaHCO3, Na2SO4, and Na2CO3.ResultsWe found that alkaline salt stress suppressed more pronouncedly the photosynthesis and growth of maize plants than salinity stress. Under alkaline salt stress conditions, metal ions formed massive precipitates, which ultimately reduced plant nutrient availability. On the other hand, high neutral salt stress induced metabolic changes in the direction of gluconeogenesis leading to the enhanced formation of sugars as a reaction contributing to the mitigation of osmotic stress. Thus, the active synthesis of sugars in shoots was essential to the development of salt tolerance. However, the alkaline salt stress conditions characterized by elevated pH values suppressed substantially the levels of photosynthesis, N metabolism, glycolysis, and the production of sugars and amino acids.ConclusionsThese results indicate the presence of different defensive mechanisms responsible for the plant responses to neutral salt and alkaline salt stresses. In addition, the increased concentration of organic acids and enhanced metabolic energy might be potential major factors that can contribute to the maintenance intracellular ion balance in maize plants and counteract the negative effects of high pH under alkaline salt stress.

Origin and history of the oils in the Lawton oil field, southwestern Oklahoma

The Lawton oil field is located on the Wichita Mountain uplift in southwestern Oklahoma. This study focused on addressing three problems related to the Lawton oil field: (a) what is (are) the source(s) of the oils; (b) have the oils been subjected to alteration since emplacement; and (c) what is the filling history of the field? Eighteen oils and one seep sample were collected and characterized by a variety of geochemical techniques including bulk composition, biomarkers, and stable carbon isotopes in order to address these questions. Source rocks in this region are absent following the Pennsylvanian-age Wichita orogeny but biomarkers and stable isotopic data suggest the source of these oils is probably the Woodford Shale. Despite the fact that all of these oils were recovered from reservoirs at depths between 125 and 1,000 ft (38 and 305 m), none of them appeared to be extensively biodegraded as manifested by the abundance of the complete range of n-alkanes. However the presence of 25-norhopanes in all eighteen samples suggests that these oils are mixtures of various proportions of degraded and non-degraded (or slightly degraded) oils. The seep sample, and some oils, have a relatively high abundance of the C32 ββ 22R hopanoic acid, relative to the C31 ββ 22R hopanoic acid, with the presence of these ββ 22R hopanoic acids suggesting the oils have been degraded aerobically at some point in their history. It was also noted that the concentration of the C31 ββ 22R hopanoic acid is higher in the shallower reservoirs than in the deeper reservoirs possibly indicating slightly higher levels of degradation in the shallower reservoirs compared to the deeper reservoirs. A hydrocarbon accumulation model has been proposed for this field based on two main reservoir charging periods. The initial charge of crude oil was biodegraded, probably under anaerobic conditions. The second charging period took place after (or together with) the uplift of the Wichita Mountains and subsidence of the southern part of the Anadarko Basin leading to deeper burial of the source rock and production of higher maturity oil, which subsequently filled the reservoirs containing the degraded oil and may still be recharging these shallow reservoirs today.

Determination of Hydroquinone with a Carbon Nanotube/Polyurethane Resin Composite Electrode

ABSTRACTA new composite electrode based on multi-walled carbon nanotubes and a polyurethane resin was evaluated using potassium ferricyanide and hydroquinone as probes. The device was used for the determination of hydroquinone in a cosmetic formulation. The effect of using multi-walled carbon nanotubes and graphite mixtures in various proportions was also investigated. Cyclic voltammetry and scanning electron micrography were used for characterization of electrode compositions. Hydroquinone was determined using a 60% (m/m) multi-walled carbon nanotubes/polyurethane resin electrode by differential pulse voltammetry with a linear dynamic range from 0.05 to 1.12 m mol L−1 and a limit of detection of 12 µ mol L−1. The analysis of commercial cosmetic formulation was performed by differential pulse voltammetry and high-performance liquid chromatography as a comparison method. The results for both procedures agreed at the 95% confidence level according to Student’s t-test. The reported electrode was mechanically robust and provided reproducible results.

Toxicity and medical countermeasure studies on the organophosphorus nerve agents VM and VX.

To support the effort to eliminate the Syrian Arab Republic chemical weapons stockpile safely, there was a requirement to provide scientific advice based on experimentally derived information on both toxicity and medical countermeasures (MedCM) in the event of exposure to VM, VX or VM–VX mixtures. Complementary in vitro and in vivo studies were undertaken to inform that advice. The penetration rate of neat VM was not significantly different from that of neat VX, through either guinea pig or pig skin in vitro. The presence of VX did not affect the penetration rate of VM in mixtures of various proportions. A lethal dose of VM was approximately twice that of VX in guinea pigs poisoned via the percutaneous route. There was no interaction in mixed agent solutions which altered the in vivo toxicity of the agents. Percutaneous poisoning by VM responded to treatment with standard MedCM, although complete protection was not achieved.

The 'triple contrast' method in experimental wound ballistics and backspatter analysis.

In practical forensic casework, backspatter recovered from shooters' hands can be an indicator of self-inflicted gunshot wounds to the head. In such cases, backspatter retrieved from inside the barrel indicates that the weapon found at the death scene was involved in causing the injury to the head. However, systematic research on the aspects conditioning presence, amount and specific patterns of backspatter is lacking so far. Herein, a new concept of backspatter investigation is presented, comprising staining technique, weapon and target medium: the 'triple contrast method' was developed, tested and is introduced for experimental backspatter analysis. First, mixtures of various proportions of acrylic paint for optical detection, barium sulphate for radiocontrast imaging in computed tomography and fresh human blood for PCR-based DNA profiling were generated (triple mixture) and tested for DNA quantification and short tandem repeat (STR) typing success. All tested mixtures yielded sufficient DNA that produced full STR profiles suitable for forensic identification. Then, for backspatter analysis, sealed foil bags containing the triple mixture were attached to plastic bottles filled with 10% ballistic gelatine and covered by a 2-3-mm layer of silicone. To simulate backspatter, close contact shots were fired at these models. Endoscopy of the barrel inside revealed coloured backspatter containing typable DNA and radiographic imaging showed a contrasted bullet path in the gelatine. Cross sections of the gelatine core exhibited cracks and fissures stained by the acrylic paint facilitating wound ballistic analysis.

Selective recovery and separation of nickel and vanadium in sulfate media using mixtures of D2EHPA and Cyanex 272

In this research, selective recovery and separation of nickel and vanadium in sulfate media was investigated by solvent extraction using D2EHPA, Cyanex 272, and their mixtures in various proportions. For this purpose, synthetic sulfate solutions of nickel and vanadium were prepared in 2g/L of each metal. After dilution of the organic solvents in kerosene with the ratio of 1–4, experiments were carried out in the pH range of 1.0–7.0 in steps of 0.5 at ambient temperature. Solvent extraction of nickel and vanadium by sole D2EHPA was performed and the extraction percentages were determined to be 90% and 80% for nickel and vanadium, respectively. However, the co-extraction of nickel and vanadium by D2EHPA can be increased with increasing equilibrium pH and temperature. It was shown that using sole D2EHPA, pH50 (the pH at 50% metal extraction) values for nickel and vanadium were 3.5 and 2, respectively; which is not appropriate for the efficient simultaneous separation of nickel and vanadium. Adding Cyanex 272 to D2EHPA in the organic phase, leads to a right shifting of extraction isotherm of nickel and a slight left shifting of the extraction isotherm of vanadium; thus, improves the separation of nickel over vanadium. To optimize the recovery and separation process of nickel and vanadium from the sulfate leach liquor, the influence of different D2EHPA to Cyanex 272 ratios and various temperatures (25, 35, 45, and 55°C) were studied. As a result, optimum separation of vanadium over nickel was achieved with a Cyanex 272 to D2EHPA ratio of 0.35M: 0.25M. Based on the optimum results, pH50 values for nickel and vanadium were shifted from 3.5 to 4.75 and from 2 to 1.75, respectively.

Phenolic compounds from roots of Rhodiola litvinovii

Plants of the genus Rhodiola (Crassulaceae) typically have a high content of biologically active compounds. R. rosea (golden root) is a medicinal plant that is used in folk and modern medicine. Therefore, it seemed interesting to study other species of Rhodiola. Four species of this genus are indigenous to Uzbekistan [1]. The chemical composition of the population of R. litvinovii Boriss. growing in Uzbekistan is practically unstudied [2]. Six phenolic compounds were isolated previously from a population of this plant growing in Siberia (Russia) [3–5]. We studied roots of R. litvinovii collected during flowering in the western Tien-Shen (Pskem Range, Bostandyk District, Tashkent Region, RU) in September 2010. For this, roots of R. litvinovii (2000 g) were extracted exhaustively with EtOH (40%) at room temperature by percolation (24 h). The combined extracts were evaporated in vacuo. The condensed thick residue (0.7 L) was diluted with H2O (1:1) and worked up successively with petroleum ether, CHCl3, EtOAc, and n-BuOH. The condensed EtOAc extract was placed on a chromatography column of silica gel that was eluted sequentially with CHCl3 and CHCl3:MeOH mixtures of various proportions. The resulting separate eluates were re-chromatographed over Sephadex LH-20 with elution by H2O:MeOH mixtures with increasing gradient of MeOH. The chromatographic separation isolated four known compounds that were identified by comparing their IR, UV, PMR, and 13C NMR spectra with the literature. p-Tyrosol (p-hydroxyphenyl-ethanol) (1), white needle-like crystals, C8H10O2, mp 94–95°C (CHCl3:MeOH, 4:1). UV spectrum (MeOH, max, nm): 204.36, 223.93, 278.27. IR spectrum (KBr, , cm –1): 3390–3144 (OH), 2879 (CH2), 1613, 1598, 1513 (aromatic ring), 817 (p-substituted benzene ring). 13C NMR spectrum (100 MHz, CD3OD, , ppm): 131.20 (C-1), 130.99 (C-2), 116.28 (C-3), 156.88 (C-4), 116.28 (C-5), 130.99 (C-6), 39.54 (C-7), 64.72 (C-8) [6, 7]. Salidroside [p-hydroxyphenyl-( -D-glucopyranosyl)-ethanol] (2), white amorphous powder with a yellow tint, C14H20O7, mp 163–164°C (CHCl3:MeOH:H2O, 26:14:3). UV spectrum (MeOH, max, nm): 203.06, 223.90, 277.60. IR spectrum (KBr, , cm–1): 3596-3271 (OH), 2933, 2878 (CH2), 1883, 1615, 1518 (benzene ring), 1241 (phenol hydroxyl), 1073, 1023 (pyranoside), 900 ( -glycoside bond). 13C NMR spectrum (100 MHz, CD3OD, , ppm): 131.06 (C-1), 130.80 (C-2), 116.25 (C-3), 146.51 (C-4), 116.25 (C-5), 130.80 (C-6), 36.50 (C-7), 71.77 (C-8), 104.49 (C-1 ), 72.23 (C-2 ), 78.07 (C-3 ), 71.77 (C-4 ), 78.22 (C-5 ), 62.88 (C-6 ) [8]. Gallic acid (3), crystals, very soluble in alcohol and hot water, C7H6O5, mp 238–240°C. UV spectrum (EtOH, max, nm): 211, 274, Rf 0.65 (BAW, 4:1:2), 0.34 (2% AcOH); gave a blue color with iron chloride solution (1%). Identification of gallic acid (3) was confirmed by an XSA. (–)-Epigallocatechin-3-O-gallate (4), brown amorphous powder, C22H18O11, mp 210–211°C. UV spectrum (MeOH, nm): max 205, 275; min 255. IR spectrum (KBr, , cm –1): 3386, 2929, 1728, 1616, 1527, 1451, 1283, 1206, 1046, 776. 13C NMR spectrum (100 MHz, CD3OD, , ppm): 77.22 (C-2), 68.56 (C-3), 25.42 (C-4), 155.83 (C-5), 95.19 (C-6), 156.48 (C-7), 94.53 (C-8), 156.42 (C-9), 98.08 (C-10), 129.44 (C-1 ), 105.54 (C-2 ), 144.89 (C-3 ), 132.40 (C-4 ), 145.29 (C-5 ), 105.54 (C-6 ), 120.17 (C-1 ), 108.91 (C-2 ), 144.89 (C-3 ), 138.39 (C-4 ), 145.29 (C-5 ), 108.91 (C-6 ), 166.20 (COO) [9, 10]. These compounds were isolated for the first time from this plant species.

Heterogeneous Catalysis Afford Biodiesel of Babassu, Castor oil and Blends

This work describes the preparation of babassu, castor oil biodiesel and mixtures in various proportions of these oils, using alkaline compounds of strontium (SrCO3 + SrO + Sr (OH)2) as heterogeneous catalysts. The mixture of oils of these oleaginous sources was used in the production of biodiesel with quality parameters that meet current legislation. The catalyst was characterized by X-ray diffractometry (XDR), physisorption of gas (BET method), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and Fourier transform infrared spectroscopy (FTIR). The viscometric technique was used to monitor the optimization. The transesterification reactions performed using strontium compounds reached conversion rates of 97.2% babassu biodiesel (BB), 96.4% castor oil biodiesel (COB) and 95.3% Babassu/Castor Oil Biodiesel 4:1 (BBCO41).

Separation of Manganese and Iron from Reductive Leaching Liquor of Electric Arc Furnace Dust of Ferromanganese Production Units by Solvent Extraction

Electric arc furnace dust (EAFD) of ferromanganese production units, in the form of slurry, contains tar, alkalies, manganese, zinc, iron, silica, calcium, aluminum and other elements. A hydrometallurgical route based on solvent extraction technique was investigated for selective separation of manganese from the dust. Leaching of the EAFD resulted in an aqueous feed containing 4 g/L of manganese and 0.87 g/L iron. At the next stage, extraction of manganese and iron from the leach liquor was performed using D2EHPA, Cyanex 272, Cyanex 302 and their mixtures in various proportions. The synergistic effect of the extractants on the separation of iron and manganese with a mixture of D2EHPA and Cyanex 272 or Cyanex 302 was studied. Increasing the Cyanex 272/ 302 to D2EHPA ratio in the organic phase increased the distance between the extraction isotherms of manganese and Iron. The highest separation factor of iron over manganese was obtained with 15:5% v/v of Cyanex 302: D2EHPA mixture. Effects of various aromatic and aliphatic diluents, such as hexane, kerosene, and carbon tetrachloride on the extraction were also investigated.

Synergistic Effect of D2EHPA and Cyanex 272 on Separation of Zinc and Manganese by Solvent Extraction

The effect of bis-2-ethylhexylphosphoric acid (D2EHPA), bis (2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272), and tri-butyl phosphate (TBP) and their mixtures in various proportions for the separation and extraction of zinc and manganese from sulfate solutions were investigated. Experiments were carried out in the pH range of 0.5–5.0 at 25, 40, and 60°C. It was shown that the extraction of zinc and manganese by D2EHPA and/or Cyanex 272 can be increased by the increase in pH and temperature. The synergistic extraction and separation of zinc and manganese with a mixture of D2EHPA and Cyanex 272 was studied and the results showed that mixing the two extractants improved the extraction capacity of the mixture. Increasing the D2EHPA to Cyanex 272 ratio in the organic phase, caused a right shifting of extraction isotherms of manganese and zinc; shifting the manganese curve was more than zinc. The manganese curve had considerable right shifting with 5% D2EHPA and 15% Cyanex 272. TBP did not affect the zinc (Zn) and manganese (Mn) extraction. The stoichiometric coefficients of Zn and Mn were determined with 20% and 5% D2EHPA and 15% Cyanex 272 by applying the slope analysis method. The organic phase was stripped by sulfuric acid.

EFFECTS OF WHEAT STARCH EDIBLE FILMS ON RANCIDITY AND MOISTURE UPTAKE OF PISTACHIO KERNELS AS A NEW PACKAGE

ABSTRACT Wheat starch‐based films were formulated by dispersing 4 g starch in distilled water, and plasticized with Gly and PEG in different levels (Gly = 2 and 3 mL/100 mL and PEG = 0.0, 0.2, 0.3 and 0.4 mL/100 mL). The emulsion films were evaluated for mechanical properties, water vapor transmission rate (WVTR). Pistachio kernels packed in wheat starch‐based films, as well as unpacked ones, were placed in the experimental apparatus. Unpacked pistachio kernels were maintained as controls. Peroxide value (PV) and moisture uptake of control (unpacked) and packed pistachio kernels were evaluated for 56 days during storage in ambient temperature (25C). Increasing Gly content of films led to slight increase in Elongation (EL). Increasing the PEG ratio further resulted in an increase in EL for all films. No significant difference in WVTR was observed between films made from mixtures of various proportions of Gly with increasing PEG (addition) at all levels of plasticizer. Maximum moisture uptake was found (6.83 ± 0.08%) in unpacked (control) pistachio kernels, but packaging pistachios in wheat starch films led to minimize moisture uptake. Wheat starch bags reduced the rate of oxidation in pistachio kernels. Incorporation of Gly and PEG in wheat starch films had no significant effect on the PV of packed pistachios. These results suggest that wheat starch‐based films are a viable alternative packaging process for pistachio kernels and improvement of shelf life. PRACTICAL APPLICATIONSThe main advantages of using edible films are extending food shelf life, improving food quality, preventing lipid oxidation in nuts and reducing synthetic packaging materials. There has been a renewed interest in edible and biodegradable films application in food packaging. These films have the potential to replace conventional packaging in some applications. Edible films and coatings derived from polysaccharides have been under intense investigation in recent years.

A Biodegradable Scale Inhibitor for Oil Well Application

Ascorbic acid, an easily biodegradable natural product with an excellent environmental profile, was studied in an oil well downhole condition for inhibiting calcium carbonate scale deposition. Scale inhibition efficiency studied in artificial seawater and formation water mixtures of various proportions through static jar test and dynamic tube blocking tests show its calcite scale inhibition potential at high-temperature wellbore conditions. Investigation made through scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and Fourier transform infrared spectrometry revealed severe structural anomalies of CaCO3 crystals and explain the scale prevention mechanism. Its biodegradation rate studied using a UV-visible method in a marine environment is excellent and meets environment requirements. In a sensitive marine environment, ascorbic acid could be deployed as an excellent green chemical for continuous injection into the wellbore to prevent carbonate scale deposition.

Powder properties of binary mixtures of chloroquine phosphate with lactose and dicalcium phosphate

A study was conducted on the packing and cohesive properties of chloroquine phosphate in binary mixtures with lactose and dicalcium phosphate powders. The maximum volume reduction due to packing as expressed by the Kawakita constant, a, and the angle of internal flow, θ, were the assessment parameters. The individual powders were characterized for their particle size and shape using an optical microscope. Binary mixtures of various proportions of chloroquine phosphate with lactose and dicalcium phosphate powders were prepared. The bulk and tapped densities, angles of repose and internal flow, as well as compressibility index of the materials were determined using appropriate parameters. The calculated and determined values of maximum volume reduction for the binary mixtures were found to differ significantly (P< 0.05), with the Kawakita plot being more reliable in determining the packing properties. Diluent type was found to influence the flow properties of the mixtures, with dicalcium phosphate giving predictable results while mixtures containing lactose were anomalous with respect to flow. The characterization of the packing and cohesive properties of the binary mixtures of chloroquine with lactose and dicalcium phosphate would be useful in the production of powders, tablets, capsules and other drug delivery systems containing these powders with desirable and predictable flow properties.

Análise físico-química de diesel interior em mistura com biodiesel

Physical-chemical analysis of diesel blended with biodiesel. The use of alternative fuels to reduce pollutant emissions in the atmosphere is an increasingly frequent trend. Thus, it becomes necessary to research the efficiency of theses mixtures in various proportions and different conditions. To diesel oil, under the legislation, are being added 3% of biodiesel. The values of specific weight and the flashpoint of the samples of commercial diesel tested, containing 2 and 3% of biodiesel, were within the established parameters set by Brazilian legislation. The values of the peroxide index for B100 biodiesel increased with light and storage time. Nevertheless, analyzing the chromatographic profile, there were no considerable changes in the chemical composition of B100 diesel under different conditions of storage. The aim of this work was examine fossil fuels in blends with biodiesel to determine their stability as well as some physical-chemical properties.

NEUTRON-INDUCED CAVITATION TENSION METASTABLE PRESSURE THRESHOLDS OF LIQUID MIXTURES

Tensioned metastable fluids provide a powerful means for low-cost, efficient detection of a wide range of nuclear particles with spectroscopic capabilities. Past work in this field has relied on one-component liquids. Pure liquids may provide very good detection capability in some aspects, such as low thresholds or large radiation interaction cross sections, but it is rare to find a liquid that is a perfect candidate on both counts. It was hypothesized that liquid mixtures could offer optimal benefits and present more options for advancement. However, not much is known about radiation-induced thermal-hydraulics involving destabilization of mixtures of tensioned metastable fluids. This paper presents results of experiments that assess key thermophysical properties of liquid mixtures governing fast neutron radiation-induced cavitation in liquid mixtures. Experiments were conducted by placing liquid mixtures of various proportions in tension metastable states using Purdue’s centrifugally-tensioned metastable fluid detector (CTMFD) apparatus. Liquids chosen for this study covered a good representation of both thermal and fast neutron interaction cross sections, a range of cavitation onset thresholds and a range of thermophysical properties. Experiments were devised to measure the effective liquid mixture viscosity and surface tension. Neutron-induced tension metastability thresholds were found to vary non-linearly with mixture concentration; these thresholds varied linearly with surface tension and inversely with mixture vapor pressure (on a semi-log scale), and no visible trend with mixture viscosity nor with latent heat of vaporization.

Langmuir Monolayer Study toward Combined Antileishmanian Therapy Involving Amphotericin B and Edelfosine

In this work, the results of comparative studies on the effect of lysophospholipid analogue, edelfosine (ED), and its mixtures with the polyene antibiotic, amphotericin B (AmB), on model erythrocyte and parasite membranes are presented. Both compounds are known for their antileishmanian activity; however, the application of AmB is limited by its toxicity, while the treatment with alkyl-lysophospholipids (edelfosine) is expensive in addition to its lower therapeutic activity as compared to the polyene. An additional problem is the emergence of resistance to both groups of drugs. The foregoing facts inspired the investigations toward combined amphotericin B/alkyl-lysophospholipid therapy. In this aspect, the effect of edelfosine on model erythrocyte versus parasite membrane has been verified by the incorporation of the drug into binary sterol/phospholipid monolayer of the proportion corresponding to the respective cellular membrane. Afterward, amphotericin B/edelfosine mixtures of various proportions (1:9; 1:1, and 9:1) have been added into sterol/phospholipid model membranes in the concentration of 1, 5, and 10%. The interactions between amphotericin B and edelfosine in mixed monolayers have also been investigated. The obtained results indicate that differences in the organization of erythrocyte versus parasite membranes are of great importance for selectivity of edelfosine toward the parasite membrane. The mixtures of drugs practically do not modify the properties of model erythrocyte membrane; however, their incorporation in the parasite membrane is thermodynamically unfavorable and causes membrane destabilization. The strongest differences in the influence of drug mixtures on erythrocyte versus parasite model membrane occur for 1% content of 1:9 and 1:1 AmB/edelfosine mixture. Moreover, when edelfosine is combined with amphotericin B, a decrease in edelfosine concentration needed to induce a similar effect on parasite membranes as edelfosine alone does is observed. As a consequence of strong interactions between edelfosine and amphotericin B, the decrease of the activity of their mixtures on model membranes was found.