Specific Fractions Research Articles

Effect of sodium hydroxide, sodium dodecyl benzenesulfonate, and resin on the interfacial tension of asphaltenic synthetic oil extracted from acidic crude oil under low salinity condition

During the past years, the usage of new oil recovery methods known as enhanced oil recovery methods is increasing because of energy consumption rate enhancement and reservoir pressure depletion. Unfortunately, since most of the investigations were focused on crude oil, it is hard to find a generalized pattern of interfacial tension (IFT) and wettability change for different crude oils because of its complicated composition. So, it is necessary to examine the effect of specific fractions of crude oil especially resin and asphaltene fractions on the IFT and wettability alteration using systematic investigations. Although a limited number of investigations examined the interactions between these specific fractions and salts, there are no systematic reports respecting the possible interactions between asphaltene and resin fractions in the presence of alkaline and surfactant. So, in the first stage, the impact of dissolving asphaltene (0–9 wt%) in the toluene was investigated on the IFT reduction which revealed a decrease in IFT value from 34.8 to 23.3 mN/m as the asphaltene concentration was increased. Further experiments showed that the presence of MgCl2 and NaCl with a maximum concentration of 5000 ppm led to a reduction in IFT to a minimum value of 18.3 and 17.3 mN/m for NaCl and MgCl2, respectively, which means the higher impact of MgCl2 on the IFT reduction. After that, the selected optimum concentrations of MgCl2 and NaCl (5000 ppm) were used in the rest of the experiments in which the effect of resin fraction and other chemicals including sodium dodecyl benzenesulfonate (SDBS) and NaOH concentrations was examined on the IFT reduction and rock wettability. According to the obtained results, it was possible to reach the minimum IFT value of 0.08 mN/m, which is several orders lower than the original IFT value of the binary system without the chemicals using the optimum chemical formulation obtained by mixing proper concentrations of SDBS, NaOH, MgCl2, and NaCl. Moreover, the obtained optimum formulations were used through core flooding experiments which revealed the possibility of increasing the oil recovery to a maximum value of 10.1% based on the original oil in place.

Dynamic analysis of thick plates reinforced with agglomerated GNPs

In this work, the quasi-3D hyperbolic shear deformation theory (quasi-3D HSDT) is utilized to examine the dynamics of thick rectangular plates reinforced with rectangular nanofillers known as graphene nanoplatelets (GNPs). Agglomeration of the GNPs is incorporated and the mechanical characteristics like shear, elastic, and bulk moduli, Poisson's ratio, and density are analysed according to the mixture along with the Eshelby-Mori-Tanaka approach. Hamilton's principle is hired to derive the solving equations, the Navier approach is hired to present an analytical solution in the spatial domain, and the Newmark method is hired to provide an approximate solution in the time domain. The relevance of the dynamic response and the natural frequencies of the plate on several parameters are explored such as dispersion pattern and the GNPs percentage and agglomeration parameters. It is discovered that for a specific GNPs percentage, growth in the amount of agglomerated GNPs leads to lower natural frequencies and higher dynamic deflection. Meanwhile, for a specific mass fraction of the agglomerated GNPs, growth in the volume of clusters brings about higher natural frequencies and lower dynamic deflection.

Cause of Death estimation from Verbal Autopsies: Is the Open Response redundant or synergistic?

Civil registration and vital statistics systems capture birth and death events to compile vital statistics and to provide legal rights to citizens. Vital statistics are a key factor in promoting public health policies and the health of the population. Medical certification of cause of death is the preferred source of cause of death information. However, two thirds of all deaths worldwide are not captured in routine mortality information systems and their cause of death is unknown. Verbal autopsy is an interim solution for estimating the cause of death distribution at the population level in the absence of medical certification. A Verbal Autopsy (VA) consists of an interview with the relative or the caregiver of the deceased. The VA includes both Closed Questions (CQs) with structured answer options, and an Open Response (OR) consisting of a free narrative of the events expressed in natural language and without any pre-determined structure. There are a number of automated systems to analyze the CQs to obtain cause specific mortality fractions with limited performance. We hypothesize that the incorporation of the text provided by the OR might convey relevant information to discern the CoD.The experimental layout compares existing Computer Coding Verbal Autopsy methods such as Tariff 2.0 with other approaches well suited to the processing of structured inputs as is the case of the CQs. Next, alternative approaches based on language models are employed to analyze the OR. Finally, we propose a new method with a bi-modal input that combines the CQs and the OR. Empirical results corroborated that the CoD prediction capability of the Tariff 2.0 algorithm is outperformed by our method taking into account the valuable information conveyed by the OR. As an added value, with this work we made available the software to enable the reproducibility of the results attained with a version implemented in R to make the comparison with Tariff 2.0 evident.

Major and minor hysteresis loops in the enthalpy-temperature and phase fraction-temperature diagrams of solid/liquid phase change materials

A rate-independent hysteresis model originally proposed by Ivshin and Pence (1994) is extended to describe thermal hysteresis in enthalpy, specific heat capacity and phase fraction of solid/liquid phase transitions. It turns out that, even for smooth cyclic temperature variations, major and minor loops in the enthalpy-temperature diagram are not necessarily closed. Jump discontinuities may occur upon switches between heating and cooling. This issue is highly problematic: the model does not obey the law of conservation of energy. This problem particularly concerns the frequently found setting that solid and liquid heat capacities do not coincide and the phase transition enthalpy is assumed constant, i.e. independent of temperature. Two possible solutions are proposed. They follow the idea of Kirchhoff’s Law and relate temperature variations of the phase transition enthalpy to the difference in specific heat capacities of the distinct phases. Conditions for path reversibility and for the existence of closed major and minor loops (limit cycles) are given. The models show good agreement with experimental data generated by differential scanning calorimetry (DSC) of three types of paraffin-based solid/liquid phase change materials (PCM). These materials are increasingly adopted for storing thermal energy in building applications and show thermal hysteresis for complete and partial melting/solidification cycles.

The structure of forest vegetation on industrial landfills of different ages

AbstractThe purpose of the research is to describe plant community formation on the quarry surfaces to determine a path for optimal revegetation. To achieve the goal, the studies determined soil pH, the content of skeletal fraction, basal respiration, and performed the acidimetric assessment of CO2. The research program aimed to investigate the peculiarities of plant communities' formation in areas with different degrees of revitalization and investigate the influence of soil cover on plant associations. Results showed that the average basal soil respiration rate on the quarry was extremely low (about 0.3 mg CO2/g of soil/h). The CO2 content in the carbonate ranged from 0.07% to 0.7%, with the higher figures observed in older Kuzbass rather than Mosbass and Sokolovsky quarries. An analysis of soil samples from three quarries revealed four plant groups at sites associated with the prevalence of specific fractions, such as gravel, sand, silt, and stony soil. Given that Kuzbass is the oldest open‐pit mine, forest vegetation species dominate here in the surveyed areas (>40%), and this feature is typical of gravel soils. The dominant species present on the gravel substrate were downy birch (Betula pubescens), common hornbeam (Carpinus betulus), European oak (Quercus robur), Siberian spruce (Picea obovata), common juniper (Juniperus communis), Siberian larch (Larix sibirica), common pine (Pinus), and Siberian fir (Abies sibirica). Mosbass is also characterized by a diversity of similar species, though work on mineral mining there ended in 2009, more recently than in other sites. Stony and sandy soil fractions predominated in the Sokolovsky quarry, although other studied substrates were also present.

Adding Value to Mine Waste through Recovery Au, Sb, and As: The Case of Auriferous Tailings in the Iron Quadrangle, Brazil

From the colonial era to modern times, gold mining has played a crucial role in shaping Brazil’s economy, culture, and landscape, particularly in the Iron Quadrangle region. Therefore, resulting waste has accumulated in tailings structures, either from deactivated circuits or plants still in production. The present study reveals the potential assessed based on a set of metallurgical tests, assuming specific scenarios depending on the occurrence modes of interesting economic elements. For Au, calcination, leaching, and flotation are promising techniques to recover this element. Tests indicated that toxic elements such as Sb and As could be effectively reused in the form of glass. The generation of other products from dry cleaning techniques was not effective but promising since there was an enrichment of elements with Au, Fe, Al, and K in specific fractions.

PH: A core node of interaction networks among soil organo-mineral fractions

Mineral-associated organic matter (MAOM) is the largest soil organic carbon (OC) pool with the longest turnover. MAOM is expected to have relatively little sensitivity to climate change due to mineral protection, but its persistence involves several organo-mineral fractions. The uncertainty in the response of specific organo-mineral fractions to climate change hampers the reliability of predictions of MAOM preservation in the future. Here, we applied a sequential chemical fractionation method integrated with network analysis to investigate MAOM stabilization mechanisms across five alpine ecosystems: alpine desert, alpine steppe, alpine meadow, alpine wetland, and alpine forest. Hierarchical cluster analysis revealed grouping of seven extractable OM fractions in MAOM into three OM clusters: a cluster with weak bondings consisting of water-soluble OM (WSOM) and weakly adsorbed fractions (2.1–21.3% of total OC); a cluster with metal-bound complexes comprising Ca-OM complexes and Fe/Al-OM complexes (3.8–12.2% of total OC); and a cluster with strong bonding composed of Al oxyhydroxides, carbonates and Fe oxyhydroxides (12.2–33.5% of total OC). The relative percentages of OM from soils of the five ecosystems in the three clusters exhibited distinct pH dependence patterns. With the increase in pH, the cluster with weak bondings decreased, and that with strong bondings increased, while the one with metal-bound complexes showed a maximum at weakly acidic pH. Organo-mineral fractions and metal cations in MAOM constructed a complex network with pH as the central node. Results suggest that precipitation does not only alter vegetation type and microbial biomass but also regulate soil pH, which is balanced by specific metal cations, thus resulting in particular pH preference of specific OM clusters. These findings demonstrate that soil pH plays a central role in unveiling MAOM dynamics and can serve as a good predictor of soil organo-mineral fractions across alpine ecosystems.

Chayote leaves display seasonal variation in phytoestrogenic activities and phenolic content

Chayote (Sicyos edulis Jacq.) is a popular vegetable in the Philippines and has been recognized for its nutritional value and bioactive compounds, including phenolic acids found in its edible parts. Hence, this study sought to determine whether extracts from S. edulis shoots can elicit a bioactive estrogenic response. Specifically, the study determined whether the location of cultivation or monsoon season of collection would influence the estrogenic activities of S. edulis extracts. Here, we found that a specific fraction (F5.6) of S. edulis shoots isolated through solid-phase extraction (C-18 and HLB) inhibited the transactivation of an estrogen-induced luciferase reporter gene in an estrogen receptor-positive cell line T47D without affecting cell viability, independently of the farm source and the season of sample collection. This inhibition was also seen in the E2- induced expression of superoxide dismutase 2 (SOD2), an antioxidant enzyme upregulated in advanced breast cancer cells. In contrast, the phenolic content in the F5.6 fraction varied across seasons, with a higher content found during the northeast monsoon season (0.175 ± 0.027 mg GAE/mg sample) than the southwest monsoon seasons (0.043 ± 0.015 and 0.051 ± 0.012 mg GAE/mg sample). The high phenolic content increased the ratio of estrogen receptor alpha to beta transcripts and the mRNA expression level of the estrogen-responsive gene, growth regulation by estrogen in breast cancer 1 (GREB1A), in T47D cells. Overall, this study showed how seasonal variation may affect the phenolic content of S. edulis and influence the plant’s bioactivity, providing a potential cultivation strategy in obtaining extracts with the intended bioactivity.

Fluorimetric microplate assay for the determination of extracellular alkaline phosphatase kinetics and inhibition kinetics in activated sludge

The microbial enzyme alkaline phosphatase contributes to the removal of organic phosphorus compounds from wastewaters. To cope with regulatory threshold values for permitted maximum phosphor concentrations in treated wastewaters, a high activity of this enzyme in the biological treatment stage, e.g., the activated sludge process, is required. To investigate the reaction dynamics of this enzyme, to analyze substrate selectivities, and to identify potential inhibitors, the determination of enzyme kinetics is necessary. A method based on the application of the synthetic fluorogenic substrate 4-methylumbelliferyl phosphate is proven for soils, but not for activated sludges. Here, we adapt this procedure to the latter. The adapted method offers the additional benefit to determine inhibition kinetics. In contrast to conventional photometric assays, no particle removal, e.g., of sludge pellets, is required enabling the analysis of the whole sludge suspension as well as of specific sludge fractions. The high sensitivity of fluorescence detection allows the selection of a wide substrate concentration range for sound modeling of kinetic functions.•Fluorescence array technique for fast and sensitive analysis of high sample numbers•No need for particle separation – analysis of the whole (diluted) sludge suspension•Simultaneous determination of standard and inhibition kinetics

An in vitro analysis of the hemostatic efficacy of fibrinogen precipitation with varied keratin fraction compositions

In preclinical studies, human hair has demonstrated effective hemostatic properties, potentially attributed to keratin proteins facilitating rapid conversion of fibrinogen to fibrin during coagulation. However, the rational use of human hair keratin for hemostasis remains unclear, given its complex mixture of proteins with diverse molecular weights and structures, leading to variable hemostatic capacity. To optimize the rational utilization of human hair keratin for hemostasis, we investigated the effects of different keratin fractions on keratin-mediated fibrinogen precipitation using a fibrin generation assay. Our study focused on high molecular weight keratin intermediate filaments (KIFs) and lower molecular weight keratin-associated proteins (KAPs) combined in various ratios during the fibrin generation. Scanning electron microscope analysis of the precipitates revealed a filamentous pattern with a broad distribution of fiber diameters, likely due to the diversity of keratin mixtures involved. An equal proportion of KIFs and KAPs in the mixture yielded the most extensive precipitation of soluble fibrinogen in an in vitro study, potentially due to structure-induced exposure of active sites. However, all hair protein samples exhibited diverse catalytic behaviors compared to thrombin, highlighting the potential of utilizing specific hair fractions to develop hair protein-based hemostatic materials with optimized capacity.

Role of flavonoids in digestive tract cancer prevention - a review article

Introduction: Flavonoids are bioactive chemical compounds crucial for the functioning of plant organisms. Recently, they have been intensively studied in search of their potential application in medicine. One of the most popular fields in that regard is oncology. Digestive tract cancers are still a challenge for contemporary medicine. Our diet seems to have a direct impact on the etiology of colorectal, gastric, and esophageal cancers. The relationship between the consumption of flavonoids, their specific fractions, and digestive tract cancer morbidity is nowadays frequently investigated.Purpose: This review article aims to discuss the most recent scientific reports and summarize the current state of knowledge, considering the role of flavonoids in digestive tract cancer prevention.Materials and methods: Our work is based on articles accessed through medical information databases (Google Scholar, PubMed, CrossRef), various scientific books, and official NFZ and WHO-certified sites.Results: Total flavonoid intake lowers gastric and esophageal cancer morbidity. A high amount of dietary catechins prevents the growth of gastric and colorectal cancer. Increased consumption of anthocyanidins, flavones, and flavanones decreases esophageal cancer morbidity. Isoflavones, procyanidines, anthocyanidins, flaonols, and flavones severely decrease the chance of developing colorectal cancer.Conclusions: Flavonoids can play an important role in digestive tract cancer prevention. They suppress the growth of colorectal, gastric, and esophageal cancers. Nevertheless, new, high-quality studies are needed in order to compile adequate procedures and bring new, potential drugs to the market.

Core/rim microstructure of Ti(C, N) cermets with low nickel-molybdenum binder content

We investigated the influence of the basic component concentration on the microstructure of the KNT3 and KNT3 tungsten-free hard alloys (TFHA), focusing on ceramic-metal samples (cermets) with a low nickel-molybdenum binder content. The microstructure of the sintered cermets was analyzed using reflected electron images of thin sections obtained with a scanning electron microscope. Our analusis revealed that the KNT alloy exhobits a core/rim structure (CRM). We observed that decreasing the Ni–Mo binder content leads to a significantincrease in the rim size isurrounding the Ti(C, N) core in the sintered alloy. We also investigated the effect of the plasticizer on the formation of the core/rim microstructure with a low binder content. Furthermore, we found that the absence of nitrogen-enriched areas in the Ti(C, N) grains increases the molybdenum diffusion rate across the refractory phase interfaces during the cooling stage, resulting in a higher specific volume fraction of the shell in the cermet microstructure.

Glomerular endothelial glycocalyx-derived heparan sulfate inhibits glomerular leukocyte influx and attenuates experimental glomerulonephritis.

Proliferative forms of glomerulonephritis are characterized by the influx of leukocytes, albuminuria, and loss of kidney function. The glomerular endothelial glycocalyx is a thick carbohydrate layer that covers the endothelium and is comprised of heparan sulfate (HS), which plays a pivotal role in glomerular inflammation by facilitating endothelial-leukocyte trafficking. We hypothesize that the exogenous glomerular glycocalyx may reduce the glomerular influx of inflammatory cells during glomerulonephritis. Indeed, administration of mouse glomerular endothelial cell (mGEnC)-derived glycocalyx constituents, or the low-molecular-weight heparin enoxaparin, reduced proteinuria in mice with experimental glomerulonephritis. Glomerular influx of granulocytes and macrophages, as well as glomerular fibrin deposition, was reduced by the administration of mGEnC-derived glycocalyx constituents, thereby explaining the improved clinical outcome. HSglx also inhibited granulocyte adhesion to human glomerular endothelial cells in vitro. Notably, a specific HSglx fraction inhibited both CD11b and L-selectin binding to activated mGEnCs. Mass spectrometry analysis of this specific fraction revealed six HS oligosaccharides, ranging from tetra- to hexasaccharides with 2-7 sulfates. In summary, we demonstrate that exogenous HSglx reduces albuminuria during glomerulonephritis, which is possibly mediated via multiple mechanisms. Our results justify the further development of structurally defined HS-based therapeutics for patients with (acute) inflammatory glomerular diseases, which may be applicable to non-renal inflammatory diseases as well.

Yeast cell wall extracts from Saccharomyces cerevisiae varying in structure and composition differentially shape the innate immunity and mucosal tissue responses of the intestine of zebrafish (Danio rerio).

With the rising awareness of antimicrobial resistance, the development and use of functional feed additives (FFAs) as an alternative prophylactic approach to improve animal health and performance is increasing. Although the FFAs from yeasts are widely used in animal and human pharma applications already, the success of future candidates resides in linking their structural functional properties to their efficacy in vivo. Herein, this study aimed to characterise the biochemical and molecular properties of four proprietary yeast cell wall extracts from S. cerevisiae in relation to their potential effect on the intestinal immune responses when given orally. Dietary supplementation of the YCW fractions identified that the α-mannan content was a potent driver of mucus cell and intraepithelial lymphocyte hyperplasia within the intestinal mucosal tissue. Furthermore, the differences in α-mannan and β-1,3-glucans chain lengths of each YCW fraction affected their capacity to be recognised by different PRRs. As a result, this affected the downstream signalling and shaping of the innate cytokine milieu to elicit the preferential mobilisation of effector T-helper cell subsets namely Th17, Th1, Tr1 and FoxP3+-Tregs. Together these findings demonstrate the importance of characterising the molecular and biochemical properties of YCW fractions when assessing and concluding their immune potential. Additionally, this study offers novel perspectives in the development specific YCW fractions derived from S. cerievisae for use in precision animal feeds.

Use of coal-fired slag in filling bodies with early strength for mining applications

The global output of coal-fired slag (CS) has far exceeded 300 million tons, and the annual output in China is 4.5 billion tons, which seriously affects the ecological security. Additionally, with the continuous increases in mine production capacities, the filling cost continues to rise, which seriously affects the normal production levels of the mines. To reduce the filling cost and make full use of the CS, this study was designed to realize diversified application of coal-fired slag (CS) as a backfill with early strength. First, physical and chemical analyses were conducted for coal-fired slag powder (CSP), fly ash (FA), flue gas desulfurization gypsum (FGDG) and mine waste rock (MWR). Based on the alkali excitation theory, mixture design, response surface theory and early strength testing of the backfill, the optimal ratio for the solid waste cementitious material and the backfill with early strength was determined. The primary and interaction effects of the backfill were analysed. Finally, the hydration mechanism for the CS-based cementing materials was revealed by monitoring the resistivity and water content and with scanning election microscopy (SEM), X-ray diffraction (XRD) and thermogravimetry/differential scanning calorimetry (TG-DSC) analyses of the hydration products. The results showed that (1) the total amount of SiO2 and Al2O3 in the CS was 61.08%, and the content of CaO was 17.3%, which indicated potential gelling activity. (2) The backfill with early strength was prepared by mixing CSP, FGDG and FA at 70%, 3% and 27%, with MWR and CS exhibiting a specific mass fraction (81%), binder-sand ratio (4:6) and CS-MWR ratio (5:5). The 3 d and 7 d uniaxial compressive strengths of the backfill were 1.7 MPa and 3 MPa. (3) The CS-MWR ratio of the backfill and the interaction between the CS-MWR ratio and binder-sand ratio significantly influenced on the early uniaxial compressive strength. (4) The early hydration process for the CS-based cementitious materials included the dissolution period, the induced formation and induction period and the condensation and hardening period. At 3 d, the hydration products were mainly generated by the CSP (the total amount of hydration products produced was 7.01%), while at 4 d–7 d, the FA was involved (the total amount of hydration products produced was 7.37%. The results of this research provide theoretical guidance for using CS to develop low-cost backfills with early strengths for application in mines.

SUMO Modification of Hepatitis B Virus Core Mediates Nuclear Entry, Promyelocytic Leukemia Nuclear Body Association, and Efficient Formation of Covalently Closed Circular DNA.

Persistence of hepatitis B virus (HBV) infection is due to a nuclear covalently closed circular DNA (cccDNA), generated from the virion-borne relaxed circular DNA (rcDNA) genome in a process likely involving numerous cell factors from the host DNA damage response (DDR). The HBV core protein mediates rcDNA transport to the nucleus and likely affects stability and transcriptional activity of cccDNA. Our study aimed at investigating the role of HBV core protein and its posttranslational modification (PTM) with SUMO (small ubiquitin-like modifiers) during the establishment of cccDNA. HBV core protein SUMO PTM was analyzed in His-SUMO-overexpressing cell lines. The impact of HBV core SUMOylation on association with cellular interaction partners and on the HBV life cycle was determined using SUMOylation-deficient mutants of the HBV core protein. Here, we show that the HBV core protein is posttranslationally modified by the addition of SUMO and that this modification impacts nuclear import of rcDNA. By using SUMOylation-deficient HBV core mutants, we show that SUMO modification is a prerequisite for the association with specific promyelocytic leukemia nuclear bodies (PML-NBs) and regulates the conversion of rcDNA to cccDNA. By in vitro SUMOylation of HBV core, we obtained evidence that SUMOylation triggers nucleocapsid disassembly, providing novel insights into the nuclear import process of rcDNA. HBV core protein SUMOylation and subsequent association with PML bodies in the nucleus constitute a key step in the conversion of HBV rcDNA to cccDNA and therefore a promising target for inhibiting formation of the HBV persistence reservoir. IMPORTANCE HBV cccDNA is formed from the incomplete rcDNA involving several host DDR proteins. The exact process and the site of cccDNA formation are poorly understood. Here, we show that HBV core protein SUMO modification is a novel PTM regulating the function of HBV core. A minor specific fraction of the HBV core protein resides with PML-NBs in the nuclear matrix. SUMO modification of HBV core protein mediates its recruitment to specific PML-NBs within the host cell. Within HBV nucleocapsids, SUMOylation of HBV core induces HBV capsid disassembly and is a prerequisite for nuclear entry of HBV core. SUMO HBV core protein association with PML-NBs is crucial for efficient conversion of rcDNA to cccDNA and for the establishment of the viral persistence reservoir. HBV core protein SUMO modification and the subsequent association with PML-NBs might constitute a potential novel target in the development of drugs targeting the cccDNA.

A simple method to isolate fatty acids and fatty alcohols from wax esters in a wax-ester rich marine oil.

Calanus finmarchicus is one of the most important zooplankton species in the North Atlantic. The zooplankton is currently being harvested and industrially processed to a marine oil product for human consumption as a marine nutraceutical containing long-chain omega-3 polyunsaturated fatty acids. This oil is very rich in wax esters, a lipid class where fatty acids are esterified to long chain fatty alcohols. In this paper we describe a simple method to 1) isolate the wax esters from the other lipid classes present in the oil, 2) hydrolyze the wax esters, and 3) separate the fatty acids from the fatty alcohol, all by means of solid phase extraction. Starting with an average of 322 mg Calanus oil, we obtained 75 mg fatty alcohols and 63 mg fatty acids. Contrary to previously described techniques, our method neither oxidize the fatty alcohols to fatty acids, nor are the fatty acids methylated, allowing the native, unesterified fatty acids and fatty alcohols to be used for further studies, such as in cell culture experiments to study the metabolic effects of these specific lipid fractions rather than the intact oil or wax esters.

Assessment of the partitioning of coarse hydrophobic particles in the product concentrate of the CoarseAIR™ flotation system using a novel mechanical cell reference method

A new algorithm was developed to assess the coarse particle flotation performance of the CoarseAIR™ system. The objective was to quantify the partitioning of the hydrophobic particles of the feed to the overflow product concentrate stream and to the underflow reject stream, recognising the broad extent of the particle surface liberation. To assess the coarse particle flotation performance, steady state samples of the feed, overflow product concentrate, and underflow reject streams of the CoarseAIR™ were taken and the +90 μm portions used to perform batch mechanical cell flotation kinetic tests. Measurement of the flotation kinetics of all three streams was undertaken, including the ultimate recoveries of the hydrophobic particles. The algorithm was constrained by the need to describe the flotation kinetics of all three streams while also adhering to full material balance requirements within each stream and between the hydrophobic components of the three streams. The algorithm produced an overall partition curve for the CoarseAIR™ separator covering the size range from 90 to 600 µm, describing the probability of a particle having a given rate constant, k, reporting to the overflow product concentrate. At a partition number of 0.50, the value of k is referred to as k50. Hydrophobic particles having this rate constant have an equal probability of reporting to the product and the reject. The partition curve was then determined as a function of the normalised rate constant, k/kmax. Here, the value of k50/kmax was ∼0.06. Based on a previous study, this value can be used to infer a surface liberation of ∼22%. The same approach was also applied to specific narrow size fractions, resulting in similar partition curves, with the value of k50/kmax increasing with the particle size.

Araceae root and citrus fibers tend to decrease Escherichia coli adhesion and myeloperoxidase levels in weaned piglets.

Weaning is a stressful experience in the piglet's life, and it often coincides with impaired gut health. Post-weaning diarrhea in piglets is frequently caused by enterotoxigenic Escherichia coli (E. coli). The first step of an E. coli infection is the adhesion to host-specific receptors present on enterocytes, leading to pro-inflammatory immune responses. The aim of this study was to examine if specific fiber fractions in the piglet diet can prevent E. coli adhesion and subsequent immune responses. The trial included 200 piglets (Danbred × Piétrain): 10 piglets/pen × 10 pens/dietary treatment × 2 dietary treatments. From weaning until 14 days (d14) post-weaning, piglets were fed a control diet or test diet with 2 kg/ton of a mixture of specific fiber fractions derived from Araceae root and citrus. Afterwards, 1 piglet per pen was euthanized, a section was taken at 75% of small intestinal length and E. coli colonization on the mucosal epithelium was quantified by scraping and conventional plating. From the same small intestinal section, histo-morphological indices were assessed, and mucosal scrapings were analyzed for gene expression of pro- and anti-inflammatory cytokines, and NF-kB. Analyses of specific intestinal bacteria and SCFA were performed on samples of intestinal content (small intestine, caecum, colon). Fecal samples were taken to measure myeloperoxidase (MPO), calprotectin and PAP/RAG3A as biomarkers for intestinal inflammation. Piglets fed the fiber mixture tended to have decreased E. coli colonization to the mucosal epithelium (5.65 vs. 4.84 log10 CFU/g; P = 0.07), less E. coli in the caecum (8.91 vs. 7.72 log10 CFU/g; P = 0.03) and more Lachnospiraceae in the colon (11.3 vs. 11.6 log10 CFU/g; P = 0.03). Additionally, the fiber mixture tended to increase cecal butyric acid (10.4 vs. 19.1 mmol/kg; P = 0.07). No significant effect on histo-morphological indices and on gene expression of pro- and anti-inflammatory cytokines and NF-kB was observed. The fecal MPO concentration tended to decrease (20.2 vs. 10.4 ng/g; P = 0.07), indicating less intestinal inflammation. In conclusion, this study showed that specific fiber fractions from Araceae root and citrus in piglet weaner diets may decrease the risk of pathogen overgrowth by reducing E. coli adhesion and intestinal inflammation.

Experimental study on the effect of asphaltenes on wax removal rate

ABSTRACT Asphaltenes are the most polar component with the largest average molecular mass in crude oil, and they are important to investigate the effect of the interfacial activity of asphaltene on the efficiency of wax removal. In order to investigate the effect of in-situ asphaltene utilization on the wax removal rate, a dynamic wax removal device is developed. The effects of the asphaltene mass fraction, the water temperature, the cold finger temperature, and the rotation speed of a rotating cylinder on the wax removal rate of the pipeline at a specific mass fraction are investigated. The results show that the wax removal rate increases and then decreases with the increase in asphaltenes mass fraction, and the maximum rate is 3.5%. The wax removal rate considerably increases at 3.5% asphaltenes mass fraction with the increase in the water temperature; the increase in cold finger temperature and the rotation speed of rotating cylinder also contributes to the wax removal increase in rate. The optimal wax removal rate was 5.8 g/min by orthogonal test. In addition, the wax removal rate increased significantly with the increase in water temperature; the increase in cold finger temperature and the increase in rotor speed also contributed to the increase in wax removal rate.