Aqueous suspensions of allophane show relatively high viscosity, presumably because of strong particle interaction between the unit particles. To test this hypothesis, we measured the particle weight and particle size of allophane during a dispersion using the light scattering method. The particle weight was more than several hundred times larger than that of the unit particle, and the size was 100–400 nm, whereas the Stokes’ diameter of the particles in the sample was less than 50 nm. Particle weight and size varied with the pH of the sample. Particle sizes were cross-checked by ultrafiltration through membrane filters. The experimental findings show that the unit particles of allophane within dilute dispersions appear to be associated like strings of beads, forming domains (primary floccules) about 100 nm in diameter. When these domains coagulate under certain conditions, they do not grow analogously but form clusters, such as secondary floccules, then precipitate. Formation of secondary flocculation of loose structure accounts for the maximum relative viscosity at the transition pH between dispersion and coagulation.

The project ‘Last Neanderthals at the Crossroads of Central Europe and the Mediterranean’ (NECEM) combines lithic analyses of previously excavated material with new sampling for dating and environmental DNA. New radiocarbon dates from Vindija, presented here, help clarify the chronology of late Neanderthal and early modern human occupations in South-eastern and Central Europe.

Preparation of bones for radiocarbon (14C) dating is still quite a challenge for researchers. The methods are being tested and improved, to increase reliability of dating results and to verify the previous ones. In this work, a set of gelatine samples, extracted from Cervus elaphus and Cervus canadensis bones from various sites in Europe and a set of human bones from archaeological sites in Poland were subjected to retreatment using ultrafiltration in Gliwice Radiocarbon Laboratory. The tested samples represent a wide range of ages, from older than 40,000 14C years BP to modern. The prepared material was subjected to the measurement of C/N atomic ratios and 14C dating using the accelerator mass spectrometry (AMS) technique. Also, the stable isotopes (δ13C and δ15N) values were determined. In a few cases ultrafiltration allows to improve gelatine quality for long-stored samples, by increasing the %C and %N as well as decreasing C/Nat ratios. Nevertheless, this effect was not observed for majority of the samples. Remeasurements of long-term stored samples give mostly the same 14C ages for ultrafiltered ones and for those without ultrafiltration.

The negative effects of dye-contaminated wastewater on humans and the environment are well known, so the wastewater must be treated carefully before discharge into the environment. To overcome those impacts, the search for environmentally friendly and low-cost materials is essential, especially in developing countries The objective of the present study was to determine the feasibility of using bauxite from Malaysia as a new and efficient ceramic, hollow-fiber membrane for the degradation of reactive dyes in wastewater. A porous, hollow-fiber membrane was fabricated from bauxite (BHFM) using a phase-inversion technique, followed by sintering at various temperatures. The BHFM consisted of two types of voids, having either a finger-like or a sponge-like structure. As the sintering temperature was increased, the porosity of the BHFM decreased from 46.5 to 9.5%. The greatest mechanical strength of 308.1 MPa was achieved when the BHFM was loaded with 55 wt.% of bauxite and sintered at 1450°C. The remaining 45 wt.% consisted of solvent, polymer binder, and dispersant. The BHFM functioned well as a membrane for microfiltration and a support membrane for ultrafiltration. BHFM with loading of 45 wt.%, 50 wt.%, and 55 wt.% successfully eliminated 90%, 94%, and 98% of 10 ppm reactive dye (RB5) when sintered at the highest temperature.

This study was designed to show the changes in glycolmacropeptides (GMPs) of whey protein solution (WPS) due to different pretreatments before and after ultrafiltration (UF). The combined form of two variants (A&B) of GMPs is a helpful compound for nutritional management of phenylketonuria and ulcerative-colitis diseases and has low content of phenylalanine (Phe). WPS with 10% concentration was prepared, acidified (adjusted to pH = 3.0), and passed through a PES (polyethersulfone) membrane in the 1st-stage of ultrafiltration (UF-1). Then the resulting permeate was neutralized and went through the 2nd-stage of ultrafiltration (UF-2) under similar conditions. Four experiments of TRT-CON, CON-TRT, TRT-TRT, and CON-CON were used with different pretreatments, where TRT was a mixing-treatment of 30 min at 150 RPM applied either after acidification of WPS or after neutralization of first permeate and before UF-2 process. While the concentration and purity of the combined GMPs in UF-2 retentate in TRT-TRT respectively were >95.6 and 99.5%, its Phe became <10 ppm among the experiments. Highly glycolyzed polymers of GMPs (MW = 45–50 kDa) were formed in the TRT-TRT experiment and went through the pore sizes of PES membrane of UF-1 easily because of their flexible structure. However, they remained in the UF-2 retentate, due to to the formation of bulky polymers. The TRT-TRT experiment had the highest reversible and irreversible resistances for passing through the UF-1 and remaining on the UF-2 membranes, and its fouling index was significantly less than other experiments.

Nine burials from Tunnug 1 site in Tuva Republic, which contained human and animal bones as well as remains of wood, were chosen for intercomparison study of preparation methods. Nine human bones, nine animal bones and 11 pieces of wood were prepared. Gelatin extracted from bones was purified using the UF method but the extraction from bones was modified with respect to acid and base treatment. Wood samples were treated as whole using acid-base-acid and cellulose was extracted for comparison. The results confirmed a highly consistent chronology of the sites centered at 200–400 CE, however, a few bones resulted in an offset between ages obtained by different methods. The extraction of cellulose was limited due to the poor preservation of wood. Our results highlight problems of dating poorly preserved bones and wood.

Collagen extraction depends on the state of bone preservation, and the acidity of Brazilian soils often prevents the use of this material for radiocarbon dating. When available, however, bone samples constitute very important chronological records for both archaeological sites and natural depositional sites of specific animals. The extraction of collagen was performed using two filters, the first aiming to remove insoluble contaminants, and the second, a vivaspin ultrafilter 30KD to retain large molecular weight materials. The collagen was liofilized and converted to CO2 by combustion in sealed quartz tubes with CuO and Ag. The graphite was produced by zinc reduction in independently sealed Pyrex™ tubes. In order to verify the accuracy of this protocol, we analyzed a modern bone and four previously dated fragments, including those from the Sixth International Radiocarbon Intercomparison (SIRI), and a fragment of human bone from the Amourins site, a Brazilian shellmound. The results for the known age material are in agreement with the expected and the studied sector of Amourins shellmound was dated 4100–3900 years cal BP from a chronological model performed with charcoal dating found in different stratigraphic layers. Samples were dated at the radiocarbon laboratory of Universidade Federal Fluminense (LAC-UFF) in Brazil.

Bone is one of the most complex sample materials used for radiocarbon (14C) dating. The installation of the EnvironMICADAS AMS at HEKAL (department of ICER) in 2011 required the adoption of new sample preparation techniques for small bone samples. Since then, hundreds of procedural background and known-age bones have been processed using our modified Longin method (MLM) and dated along with unknown samples. Their results are used in this study to assess the reproducibility of our current bone preparation method and the real uncertainty of the final age result. In addition, using the background samples, which are included in each bone measurement batch, blank correction of the unknown samples could also be performed. The mean F14C value of our bone blanks is generally better than 0.005 (∼42,500 BP) alongside 0.0013 SD. Good reproducibility was confirmed by the results of the laboratory known-age bone as well, where the standard deviation of the mean is better than 0.0025. In addition, the results of the three bone samples used in an ultrafiltration (UF) test study did not show notable differences from the ones obtained by our current protocol in 1σ uncertainty range but more experiments will be performed in the near future.

Modulating conditions during ultrafiltration of skim milk appears to be a feasible strategy to obtain milk protein concentrates (MPC) with tailored functionalities. Adjustment of pH and process temperature attenuated properties of casein micelle resulting in enhanced emulsification capacity. Additional pre-treatment options such as addition of calcium chelators can further impact on the functionality of MPC by modifying the calcium distribution and casein micelle integrity. The objective of the project was to establish effects of pre-treating skim milk with calcium chelators (EDTA or citrate) in concentrations between 10 to 30 mm prior to UF on the physical properties of the feed, corresponding retentates and dried MPC, including particle size, zeta potential and calcium distribution in skim milk and the corresponding retentates, as well as the physical functionalities such as solubility, heat stability and emulsifying properties. Addition of calcium chelators (EDTA or citrate), at levels 20–30 mm concentrations reduced casein micelle size as well as total, soluble and ionic calcium contents that resulted in MPC with enhanced solubility and heat stability. The emulsion capacity was, however, improved only with EDTA at 10 mm concentration. The enhanced functionality is attributed to the reduced particle size resulting from the removal of calcium from the retentate that could modify micellar casein to an extent sufficient to cause such improvements.

Two types of diet – standard and atherogenic – were used to study the effect of wheat or wheat–rye breads supplemented with 20 % acid whey concentrate after ultrafiltration on the physiological response of growing rats. The acid whey concentrate after ultrafiltration used in rat diets caused reduced weight gain (for atherogenic diet with wheat bread); growth of caecum tissue and digesta weight; a decrease in the pH of caecum digesta (for atherogenic diet); reduced activity of bacterial glycolytic enzymes; and a significant increase in total SCFA for both types of diet with wheat–rye breads containing acid whey concentrate. For wheat bread with acid whey, in standard diet, a statistically significant increase was found in the population of bifidobacteria. The results showed that the acid whey concentrates could be used as a valuable food ingredient.

The SUERC Radiocarbon Laboratory employs a one-step “background subtraction” method when calculating 14C ages. An interglacial wood (VIRI Sample K) is employed as the non-bone organic background standard, while a mammoth bone (LQH12) from Latton Quarry is used as the bone background standard. Results over several years demonstrate that the bone background is consistently around a factor of two higher and more variable than the wood background. As a result, the uncertainty on routine bone measurements is higher than for other sample types. This study investigates the factors that may contribute to the difference in F14C values and the higher variability. Preparations of collagen using modified Longin or ultrafiltration methods show no significant difference, nor does eliminating the collagen dissolution step. Two bone samples of known infinite age with respect to radiocarbon are compared and again no significant difference is observed. Finally, the quantity and age of the organic matter in the water used during the pretreatment is investigated and it is shown that there is insufficient organic matter in the reverse osmosis water to influence background values significantly. The attention is now on determining if incomplete demineralization could lead to contaminants being retained by the phosphate in the hydroxyapatite.

Kent's Cavern is one of Britain's most important Palaeolithic sites. The Torquay Natural History Society excavations in the Vestibule (1926–1928 and 1932–1938) yielded Middle and Early Upper Palaeolithic deposits as well as a fragment of human jaw (KC4). Higham et al. (2011) recently identified it as the oldest modern human fossil known from North West Europe, with a date estimated, using Bayesian modelling, at 44,200–41,500 cal bp (at 95.4% probability). However, White and Pettitt (2012) and Zilhão (2013) have claimed that the poor quality of the excavations and lack of stratigraphic integrity cast doubt on the archaeological and dating evidence from the site. Here, we present a thorough re-analysis of the excavations and show that they were in fact conducted to a reasonable standard. We also carefully examine the stratigraphic and sedimentological sequence and present twelve new AMS determinations from key contexts to test the previous model and chronology. We find that, while Trench C has good stratigraphic integrity, there is some evidence of post-depositional disruption of certain parts; some post-depositional movement is also shown by a limited number of artefact refits. There are two outlying AMS determinations dating to c. 32,000 bp. We therefore cannot exclude completely the possibility that the maxilla's age could be younger than the published probability distribution function (PDF). Our analysis lends support to the assessment by Higham et al. (2011) of the site and KC4 and shows that it offers considerable potential for future study.

Introduction. The aim of this work was to develop a list ofsuitable sensory attributes and to perform sensory quality assessment of an unprocessedpeach juice and a peach juice clarified by enzymatic treatment followed by membraneprocesses, using the attributes chosen by the trained panel. Materials andmethods. A panel of assessors was selected and trained following the quantitativedescriptive analysis methodology. A descriptive terminology with eight descriptors wassuccessfully developed. Results and discussion. The sensory analysis showedthat the juices were effectively clarified. Although the clarification by microfiltrationin a bench-scale unit did not change juice taste attributes, the characteristic color andaroma of peach juice were also removed. The scale-up of the membrane clarification processaffected all the sensory characteristics of the clarified juice, even taste. Theunpleasant cooked fruit taste and aroma could be reduced by juice clarification byenzymatic and membrane processes. The kind of membrane, membrane geometry andtransmembrane pressure used in the membrane clarification did not significantly affect thejuice sensory characteristics.

Introduction. Ultrafiltration (UF) is a single-unit operation for the clarification and fining of fruit juices. The purpose of the UF is to remove suspended solids as well as haze-inducing and turbidity-causing substances to obtain a clear juice during storage. Specifically, the polymerization of phenolic compounds and their interaction with other components (e.g., proteins) could cause a haze complex and turbidity in fruit juices, which can foul the ultrafiltration membrane. Materials and methods. Fresh pomegranate juice was clarified by the ultrafiltration process on a laboratory scale. In experimental tests performed according to the total recycle and the batch concentration mode, the effects of transmembrane pressure (TMP) and enzyme pre-treatment on permeation flux and quality of juice were studied. Results. With the total recycle mode, the effect of TMP on the color and clarity of clarified pomegranate juice was significant. The initial color of the raw pomegranate juice was reduced from 74% to 33% and the clarity decreased from 77% to 42% by UF when the TMP increased from (1 to 3.6) bar. Total phenolic rejection decreased from 45% to 21% when the TMP rose from (1 to 2) bar and remained constant above this value. With the batch concentration mode at TMP = 2 bar and velocity 1 m·s–1, the enzymatic treatment (5 U·mL–1, 300 min, T = 20 °C) of pomegranate juice provided the highest permeate flux, a decrease in total phenolics of 50% and an increased clarity of 30%. Fouling of the UF membrane during pomegranate juice processing is mainly due to the retention of polyphenols and/or proteins; thus, several blocking mechanisms were studied, using a recently developed membrane-fouling model. Analysis revealed that the membrane separation process was controlled by the gel layer mechanism of raw pomegranate juice and complete pore blocking mechanism with enzymatic pre-treatment.

The glomerular basement membrane and its associated cells are critical elements in the renal ultrafiltration process. Traditionally the anionic charge associated with several carbohydrate moieties in the glomerular basement membrane are thought to form a charge selective barrier that restricts the transmembrane flux of anionic proteins across the glomerular basement membrane into the urinary space. The charge selective function, along with the size selective component of the basement membrane, serves to limit the efflux of plasma proteins from the capillary lumen. Heparan sulfate glycosaminoglycans are anionically charged carbohydrate structures attached to proteoglycan core proteins and have a role in establishing the charge selective function of the glomerular basement membrane. Although there are a large number of studies in the literature that support this concept, the results of several recent studies using molecular genetic approaches to minimize the anionic charge of the glomerular basement membrane would suggest that the role of heparan sulfate glycosaminoglycans in the glomerular capillary wall are still not yet entirely resolved, suggesting that this research area still requires new and novel exploration.

The soluble phase of milk was separated at 20 and 80°C using ultrafiltration. The resulting permeates were then subjected to further ultrafiltration and dialysis at close to these two temperatures. It was found that pH, Ca2+ and soluble Ca decreased as the separation temperature increased both in original UF permeates and in dialysates obtained from these permeates, but P decreased only slightly. The major reason for these changes was due to the precipitation of calcium phosphate/citrate complexes onto the casein micelle with concomitant release of H+. The pH of both permeates and dialysates from milk at 20°C were slightly higher than for milk. When UF permeates collected at 20 and 80°C, were each dialysed at both these temperatures, the dialysate collected at 80°C showed much less temperature dependence for pH and ionic calcium compared with that collected at 20°C. This is in contrast to milk, which shows considerable temperature dependence for pH and ionic calcium. Further experiments revealed that the pH and Ca2+ concentration of permeates showed high temperature dependence above the temperature at which they were separated, but a much lower temperature dependence below that temperature. These findings suggest that dialysis and UF of milk at high temperature provide the best means yet for estimating the pH and ionic calcium of milk at that temperature.

The effect of ultrafiltration and diafiltration on the distribution of the calcium phosphate clusters of the casein micelle was investigated using Small Angle Neutron Scattering (SANS). In the case of ultrafiltration, fresh skim milk was subjected to concentration using membrane filtration up to 5× its original volume, the retentate was rediluted with its corresponding serum and subsequently dialyzed against reconstituted milk powder dispersed in D2O/H2O (UF 5×(D)). In the case of diafiltered samples, the samples were concentrated adding water (diafiltration) at two different levels (DF 2·5× or DF 5×) and then redispersed with D2O/H2O. In the DF 5× case, the serum components were diluted to less than 1% of their original concentration. For analysis, all samples had the same volume fraction of dispersed casein micelles (φ=0·1), which is that of the control, unprocessed skim milk. A peak in the SANS data was observed in fresh skim milk at a scattering vector, qo, of 0·034 Å−1 (directly proportional to the reciprocal characteristic length), in agreement with previous literature results. Neutron data on the ultrafiltered, UF 5×(D) and diafiltered, DF 2·5× and DF 5× milk samples showed a progressive decrease in the intensity of the peak but invariance in qo. These results, combined with the determination of soluble and insoluble calcium in the samples, suggest a progressive and irreversible removal of calcium from within the micelle during membrane filtration of milk. Using SANS it was possible to clearly show changes in the micellar calcium clusters that may not otherwise be fully determined by only measuring the amount of total and insoluble calcium in milk.

The advent of cardiopulmonary bypass in 1953, and its subsequent continuous refinements, have securely established the specialty of cardiovascular surgery. In conjunction with the improved methods of myocardial preservation, this has allowed the safe repair of acquired and complex congenital cardiac defects. During the years, the many variables of the systems used for cardiopulmonary bypass have been altered to the point that most operations are now reproducible with, relatively, low morbidity and mortality. Although in its present form the system is quite reasonable for most routine surgery, it is far from perfect. There remains, therefore, a quest for alterations to improve the system as an ongoing process. Certain complications of open-heart surgery persist and many new and unique approaches to the concept of organ protection and the treatment of these complications must be developed and refined.

In a previous study, ultrafiltration (UF) at 1·2×reduced residual chymosin activity and bitterness in exopolysaccharide (EPS)-positive reduced fat Cheddar cheese. The objective of this research was to study the effect of this level of concentration on the textural and functional characteristics of the reduced fat cheese. Ultrafiltration (1·2×) did not affect the hardness, cohesiveness, adhesiveness, chewiness, and gumminess of EPS-positive cheese. The 6-month old UF cheeses were springier than non-UF cheeses. However, the springiness of the EPS-positive cheese made from UF milk was much lower than that of the EPS-negative cheeses. Texture of the EPS-negative cheese was more affected by UF than that of the EPS-positive cheese. Differences were seen in the extent of flow between UF and non-UF cheeses at 1 and 3-months but not after 6 months ripening. Ultrafiltration increased the elastic modulus in the 6-month old EPS-positive cheeses. Higher body and texture scores were given to EPS-positive cheeses than the EPS-negative ones. Sensory panelists found the body of the UF and non-UF cheeses to be similar.