The conductivites of the Na and H ion-exchanged forms of kaolinitic clay rejects from sand-washing operations, both purified and as found naturally as a complex with soil organic matter, were examined. The two Na-clays showed linear conductivity-concentration characteristics, each having two regions with different slopes intersecting at ∼3.3% by weight of clay, which probably reflect a structural change from sol to gel. In the gel region, only the Na-counterions conducted, the reduction in conductivity with concentration being due to a smaller proportion of these ions in the Gouy layer and/or a decrease in their mobilities. In the sol, an additional, concentration-dependent conductivity arose from the electrophoretic motion of clusters of clay particles which gradually broke down on dilution. The two acid clays showed curved conductivity-concentration characteristics consistent with a weak acid dissociation equilibrium; the pKa values of 6.37 to 6.56 are close to those determined independently from titration with alkali. A stronger acid species detected in the titrations was not seen in the conductivity. The MOH2+/MOH/MO− model of the clay-surface species and one set of the predicted concentrations of each species (see preceding paper) are consistent with the observed conductivities. The MOH2+ species probably bridged the edges and faces of clay particles so that the H atoms were identical, but became different when alkali was added.

Polycations of limited molecular size were prepared from 0.1 M solutions of Fe(III)(NO3)3 and A1(NO3)3 by ultrafiltration. Various amounts of the polycations were added to Na-kaolinite, Na-mont-morillonite, and a Na-soil clay and the effect on the flocculation of the clay and electrophoretic mobility compared. Flocculation occurred just before zero net charge was obtained. Addition of further polycation resulted in the dispersion of clay with a net positive charge. The Al polycations possessed a high positive charge (0.49 per gram atom of Al), and their interaction with the clays indicated a planar shape. Adsorption of Al polycations decreased markedly the cation-exchange capacities of the kaolinite and the soil clay but had little effect on surface areas determined by low-temperature N2 adsorption. The Fe polycations were spheres 10–100 Å in diameter with a positive charge of 0.2 per gram atom. The surface areas of the kaolinite and the soil clay were substantially increased by the addition of the Fe polycations but their cation-exchange capacities were reduced by one fifth. Al polycations increased the surface areas of the montmorillonite (to 300 m2) presumably by propping open the interlamellar spaces and rendering the a-b planes accessible for nitrogen adsorption. The Al polycations in interlamellar spaces prevented collapse to 14 Å on heating to 150°C. There was no evidence of regular interlayer Fe as might be anticipated from the size of the spheres.

To evaluate the importance of oxides to the surface chemistry of acid mineral soils, clay fractions were separated from a surface and subsurface horizon of an Inceptisol representative of many of the acid soils of the Southern Tier of New York state. Portions of the clays were treated to remove selectively noncrystalline and microcrystalline Fe and A1 oxides (acid ammonium oxalate extraction), total free iron oxides (dithionite reduction in buffered citrate solution), and organic matter (hypochlorite oxidation). Charge and ion-adsorption characteristics of the treated and untreated clays were investigated by means of Ca2+- and Cl−-exchange capacities, potentiometric titrations, and electrophoretic mobility (zeta potential) measurements of the CaCl2-treated clays.

Based upon surface area and anion- and cation-exchange measurements, the Fe and A1 oxides or oxideorganic matter complexes were found to contribute a large part of the surface area and pH-dependent charge of these clays. Oxide removal increased the cation-exchange capacity (CEC) and virtually eliminated the anion-exchange capacity (AEC) at pH 3 and 5.5 while shifting the positive zeta potential (ZPC) of the B-horizon clay toward negative values. Organic matter oxidation increased the AEC at pH 3 and the CEC at pH 5.5 and markedly shifted the ZPCs of both A- and B-horizon clays toward more positive values, probably by the removal of adsorbed organics from oxide surfaces. Estimates of the ZPCs of the clays varied among the three methods used, Ca2+- and Cl−-exchange capacities giving the lowest, and electrophoresis giving the highest values.

Electrophoretic mobility of imogolite has been reported as positive (migration toward the negative electrode) below pH 9, and zero above pH 9. However, when mobility of dilute imogolite suspensions (5 × 10−3 kg/m3) was measured, it was found to be negative above pH 9. The reason that imogolite does not behave as a negative colloid when the clay concentration is not very dilute is because the imogolite forms floccules large enough to prevent migration. Imogolite has a PZNC at about pH 6, and has a PZC at pH 8.5–9.0 showing a relatively low absolute mobility under alkaline conditions compared to that under acid conditions. The fact that imogolite behaves like this is understandable given the location of negative charge appearing on the inside surface of the thin fibrous tube, according to the structural model of imogolite.

The electrochemical properties of kaolinite before and after modification with chlorodimethyl-octadecylsilane have been studied by electrophoretic mobility, surface charge titration, and extrapolated yield stress measurements as a function of pH and ionic strength. A heteropolar model of kaolinite, which views the particles as having a pH-independent permanent negative charge on the basal planes and a pH-dependent charge on the edges, has been used to model the data. The zeta potential and surface charge titration experimental data have been used simultaneously to calculate acid and ion complexation equilibrium constants using a surface complex model of the oxide-solution interface. The experimental data were modeled following subtraction of the basal plane constant negative charge, describing only the edge electrical double layer properties. Extrapolated yield stress measurements along with the electrochemical data were used to determine the edge isoelectric points for both the unmodified and modified kaolinite and were found to occur at pH values of 5.25 and 6.75, respectively. Acidity and ion complexation constants were calculated for both sets of data before and after surface modification. The acidity constants, pKa1 = 5.0 and pKa2 = 6.0, calculated for unmodified kaolinite, correlate closely with acidity constants determined by oxide studies for acidic sites on alumina and silica, respectively, and were, therefore, assigned to pH-dependent specific chemical surface hydroxyl groups on the edges of kaolinite. The parameters calculated for the modified kaolinite indicate that the silane has reacted with these pH-dependent hydroxyl groups causing both a change in their acidity and a concomitant decrease in their ionization capacity. Infrared data show that the long chain hydrocarbon silane is held by strong bonding to the kaolinite surface as it remains attached after washing with cyclohexane, heating, and dispersion in an aqueous environment.

Chlorite is a layered silicate mineral group of importance in geology, agriculture, and in the processing of mineral resources. A more detailed analysis of the surface charge of chlorite minerals is important in order to improve our fundamental understanding of such particle structures and their behavior in suspension. In this study, the anisotropic surface charging of chlorite has been established using Atomic Force Microscopy surface-force measurements with a silicon nitride tip. The surface-charge densities and surface potentials at the chlorite basal-plane surfaces and edge surface were obtained by fitting force curves with the Derjaguin-Landau-Verwey-Overbeek theoretical model. The results show that at pH 5.6, 8.0, and 9.0 the chlorite mica-like face is negatively charged with the isoelectric point (IEP) less than pH 5.6. In contrast, the chlorite brucite-like face is positively charged in this pH range and the IEP is greater than pH 9.0. The surface charging of the chlorite edge surface was found to be pH-dependent with the IEP occurring at pH 8.5, which is slightly greater than the edge surfaces of talc and muscovite due to the larger content of magnesium hydroxide at the chlorite edge surface. Findings from the present research are expected to provide a fundamental foundation for the analysis of industrial requirements, e.g. collector adsorption, slime coating, and particle interactions in the area of mineral-processing technology.

This research communication depicts the quality and authenticity of grated Parmesan cheese sold in Brazil, with novel emphasis on ripening time. The sampling included all brands manufactured and packed at Brazilian dairy plants under federal inspection and sold in Londrina between June and September 2017. A total of 24 samples were analyzed (3 batches of 8 brands) for microbiological and compositional characteristics, including urea-PAGE electrophoresis for the quantitative determination of the milk proteins. About 80% of the samples were insufficiently ripened and 32% with low-fat content. Faced with these economically motivated food frauds, the authenticity of grated Parmesan in Brazil may be under threat. It is high recommended that future surveys and regulatory agencies go further than microbiological assessment, including and emphasizing the ripening time as the main parameter of grated Parmesan cheese.

Pork is one of the most consumed meats worldwide, yet, pork quality remains an issue for the industry, mainly because of flavour, colour and water holding capacity instabilities. Castration techniques combined with dietary supplementation with ractopamine hydrochloride (RAC) seem to be a tangible solution to deal with these issues. There is a lack of knowledge of how these techniques will impact the proteomic profile and, consequently, the meat quality. The main goal of this work was to study the proteomic profile of non-aged pork meat under different sexual conditions and RAC dietary supplementation, and how the combination of these two factors impacts meat quality attributes. Forty-eight animals were distributed in six treatments, three sexual conditions (females; surgically castrated males; immune castrated males) and two diets (with RAC inclusion or without). For proteomic analysis, a sample of the Longissimus dorsi muscle was collected 24 h after slaughter and analysed using one-dimensional SDS/PAGE. The ultimate pH and colour (L*, a*, b*) were measured in the carcasses after 24 h, then meat samples were collected to measure drip, cooking and thawing losses, as well as the shear force. The interaction between gender and diet affected the ultimate pH and the L* parameter. Meat tenderness was only influenced by diet. Twenty-seven protein bands were revealed by SDS/PAGE, six of them with the protein abundance affected by diet. In conclusion, the inclusion of dietary RAC caused differences in the pork meat proteome, and more studies are necessary to fully explore the proteins involved in these changes.

Microbial transglutaminase (MTGase) is an enzyme widely used in the dairy sector to improve the functional properties of protein-based products via the formation of a network between protein molecules. The aim of this study involving cheese from the milk of donkeys was to evaluate the effects of treatment with MTGase at the concentrations of 0 (control), 5, 8 and 10 U/g milk protein on the cheese-making process parameters, as well as the physical and chemical characteristics of the resulting cheese. MTGase influenced the time of gel formation from rennet addition (P < 0.05), with a delay at the two highest concentrations, accompanied by a lower (P < 0.01) pH of cheese and the lowest (P < 0.01) loss in cheese weight at 24 h of storage. The highest gel viscosity (P < 0.01) was observed at the highest concentration of the enzyme, reaching the value of 70 mPa⋅sec after 60 min. The chemical composition and color of the cheeses were not significantly affected by the inclusion of MTGase, regardless of the enzyme concentration. These findings may be of relevance in adapting the cheese-making process and might help in the design of new dairy products from donkey's milk.

The aim of this study was to characterize the protein profile of ovarian follicular fluid (FF) of brown brocket deer (Mazama gouazoubira). Five adult females received an ovarian stimulation treatment and the FF was collected by laparoscopy from small/medium (≤3.5 mm) and large (>3.5 mm) follicles. Concentrations of soluble proteins in FF samples were measured and proteins were analyzed by 1-D SDS-PAGE followed by tryptic digestion and tandem mass spectrometry. Data from protein list defined after a Mascot database search were analyzed using the STRAP software tool. For the protein concentration, no significant difference (P > 0.05) was observed between small/medium and large follicles: 49.2 ± 22.8 and 56.7 ± 27.4 μg/μl, respectively. Mass spectrometry analysis identified 13 major proteins, but with no significant difference (P > 0.05) between follicle size class. This study provides insight into elucidating folliculogenesis in brown brocket deer.

Serum protein distribution and concentration can be affected by different physiological and pathological conditions. The aim of this study was to evaluate the changes in the concentration of serum protein fractions and haptoglobin in clinically healthy dairy buffaloes during late pregnancy and early lactation. Blood and milk samples were collected from 30 buffaloes at around 7 d before expected calving (blood only) and 7, 30 and 50 d after calving. In serum samples, the total protein, haptoglobin, albumin, α1-, α2-, β1-, β2-, γ-globulins, and albumin/globulin ratio (A/G) values were evaluated. In milk, fat%, protein%, lactose%, somatic cell score (SCS) were assessed, along with milk yield (MY) and daily milk production (DMP). The peripartum period significantly influenced (P < 0.005) total protein, albumin, haptoglobin, α2-, β2- and γ-globulins (P < 0.005). Milk yield, DMP and fat% changed significantly throughout the monitoring period (P < 0.005). Milk yield and DMP were positively correlated with total protein, albumin, β2-globulins and A/G ratio, and negatively correlated with haptoglobin and α2-globulins. These results provide new knowledge about the serum protein electrophoretic pattern in Italian Mediterranean Buffaloes during the last phase of pregnancy and early stages of lactation.

Electrophoresis of a cylinder suspended in a cylindrical tube is analytically studied in the limit of thin electric double layer approximation. The electric and fluid flow fields within the annulus, and the cylinder velocities are analytically obtained in bipolar coordinates. The results are analyzed with various values of dimensionless parameters: eccentricity, cylinder-to-tube radius ratio and tube-to-cylinder zeta potential ratio (i.e., tube-to-cylinder velocity scale ratio). The analysis shows that microvortices are generated within the annulus. By changing the parameters, different flow patterns can be created, which shows potential for mixing enhancement in micro/nanofluidics. Moreover, the cylinder not only translates but also rotates when the cylinder and tube are eccentric. The cylinder rotation might be utilized as a micromotor or an electric field detector. The cylinder trajectories show that the cylinder may approach the tube wall or rest within the tube depending on the zeta potential ratio.

The importance of seeds in the reproduction and maintenance of yellow nutsedge (Cyperus esculentus L. # CYPES) populations was evaluated. Isozyme analysis using starch gel electrophoresis was performed on 20 individuals of each of 10 widely separate populations in California. Genetic variation among individuals served as an indicator of the relative importance of asexual and sexual reproduction in each population. Eight enzyme systems were assayed from which 12 loci were resolvable, with four of those loci exhibiting variability. A maximum of four isozyme genotypes appeared in any population; only nine of 81 total potential genotypes were identified. Five populations were isozymically uniform, apparently composed of a single genotype. The remaining five populations were genotypically variable; these frequently deviated strongly from the genotype frequencies expected of a sexually reproducing population. These results indicate that sexually produced seeds are unimportant in the maintenance of yellow nutsedge populations in agricultural environments. Although viable seed may be produced, tubers appear to be the primary mode of reproduction in this species.

Electrophoretic analysis of storage protein accumulation in developing cowpea [Vigna unguiculata (L.) Walp. ‘Mississippi Purple’] seed indicated that a large increase in protein content per seed occurred between 10 and 11 days after flowering (DAF). Polypeptides with molecular weights of 54, 49, and 41 kilodaltons (kD) accumulated first, and one with a molecular weight of 59 kD appeared 2 days later at 13 DAF. Treatment of plants with glyphosate [N-(phosphonomethyl)glycine] when pods were 7 and 10 DAF prevented accumulation of the major storage protein polypeptides. The accumulation of these polypeptides was not inhibited as much when pods were 11, 12, or 13 DAF at the time of treatment with glyphosate. Pod length and seed fresh weight were inhibited by glyphosate treatment of plants bearing pods 7, 10, 11, and 12 DAF. Pod width, seed dry weight, and seed length were inhibited by glyphosate when plants bearing pods 7, 10, and 11 DAF were treated.

Genetic variability for loci governing enzyme/morphological variants and for herbicide response was determined in 10 populations of the slender wild oat (Avena barbata Pott. ex Link ♯ AVEBA), six populations of wild oat (Avena fatua L. ♯ AVEFA), and three populations of godetia (Clarkia williamsonii Lewis & Lewis). The enzyme loci were identified by starch gel electrophoresis and included peroxidase, 6-phosphogluconate dehydrogenase, esterase, and leucine aminopeptidase for the slender wild oat; peroxidase, esterase, leucine aminopeptidase, and malate dehydrogenase for the wild oat; and esterase, phosphoglucoisomerase, leucine aminopeptidase, acid phosphatase, and glutamate oxaloacetate transaminase for godetia. Morphological loci included lemma and leaf sheath hairiness for the oats. For both the enzymatic and morphological loci, levels of genetic variation for each population were quantified by a polymorphic index. The herbicide barban (4-chloro-2-butynyl 3-chlorophenylcarbamate) was used on the wild oats; bromoxynil (3,5-dibromo-4-hydroxybenzonitrile) was used on godetia. Genetic variation for herbicide response was based on genetic variances calculated from phytotoxicity scores. Populations were ranked from highest to lowest for the polymorphic indices and the genetic variances. Concordance between the rankings was tested by rank correlation. Statistically significant relationships were found between the enzyme/morphological characters and herbicide response in the slender wild oat and the wild oat. For some species, the level of genetic variation for response to herbicides appears to be associated with genetic variation for enzymatic and morphological loci.

The structure of the NiTi matrix covered by multi-layer was studied applying X-ray diffraction techniques supported by electron microscopy. Multi-layer was composed from titanium oxide (passivation) followed by mixture of the hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP) (electrophoresis). Conditions of deposition as well as sintering did not change the nominal ratio of HAp/TCP and saved their original structure. Also, the passivated NiTi matrix and with HAp/TCP-deposited layer did not change structure. However, sintering, done for HAp/TCP consolidation, introduced local differences in the lattice parameter as well as phase composition of the NiTi matrix. In consequence of that, two-steps martensitic transformation occurred in sintered NiTi/TiO2/Hap–TCP composite.

The aim of this research study is to produce high-quality TiO2 nanotube arrays using porous alumina templates. The templates are fabricated through anodizing bulk aluminum foils which can be utilized for the production of thick alumina templates. To produce the nanotube arrays, the alumina template pores are filled with the precursor sol by applying a DC electric field. Then, the deposited nanotubes are heat treated at 320 °C for 2 h and, subsequently, sintered for 2 h at 400 and 750 °C to obtain nanotubes with pure anatase and rutile phases, respectively, as confirmed by x-ray diffraction data. Scanning and transmission electron microscopy (SEM and TEM) investigations show that the nanotubes have been deposited in the channels of the nanoporous alumina template. Also, SEM investigations show the existence of a vast area of TiO2 nanotube arrays when we use semiconductor alumina templates.

The Nigerian indigenous pigs (NIP) are threatened to lose their genetic diversity through unsustainable farming practices in Nigeria. Therefore, the genetic relationships of NIP and commercially developed cross-bred pigs were evaluated to pinpoint a possible source of pure uncontaminated genetic stocks of NIP for conservation. Blood protein polymorphisms were used as a preliminary genetic analysis of blood samples from a total of 120 pigs (79 NIP from three separate locations and 41 cross-bred pigs). Nineteen polymorphic bands of the blood proteins globulin, transferrin and albumin were observed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and a phylogenetic dendrogram was developed to analyse the genetic relationship between the NIPs. The three NIPs were found to have a high genetic similarity (84 percent similarity coefficient), and were found to be distinctly different from the commercially cross-bred strains. One line from a farm in Ogbooro, Saki Oyo, Nigeria was identified as a relatively stable genetic resource that may be a suitable NIP for future conservation efforts.

We study a microfluidic flow model where the movement of several charged species is coupled with electric field and the motion of ambient fluid. The main numerical difficulty in this model is the net charge neutrality assumption which makes the system essentially overdetermined. Hence we propose to use the involutive and the associated augmented form of the system in numerical computations. Numerical experiments on electrophoresis and stacking show that the completed system significantly improves electroneutrality constraint conservation and recovers analytical results while a direct implementation of the initial model fails.

Triticum urartu Thum. ex Gandil. is a wild species identified as A-genome donor for polyploid wheats, which could be used as gene source for wheat breeding. The high-molecular weight glutenin subunits are endosperm storage proteins that are associated with bread-making quality. In T. urartu, these proteins are encoded by the Ax and Ay genes at the Glu-Au1 locus. The Ay gene of 17 Glu-Au1 allelic variants previously detected in this species has been analysed using PCR amplification and digestion of the PCR products with two endonucleases (DdeI and PstI). The combination of two restriction patterns has revealed variations between the active and inactive alleles, and within each type. This variation, especially that detected among the active alleles, could enlarge the high-quality genetic pool of modern wheat and be used for bread-making quality improvement in durum and common wheat.