NaCl Brine Research Articles

Laboratory analysis to assess shale stability for the Zubair Formation, Southern Iraq

The Zubair Formation consists of approximately 55% shale, which causes almost 70% of wellbore problems due to incompatibilities between drilling fluids and shale formations. The most common and effective solution to shale instability is through the design and selection of appropriate drilling fluids. Understanding the interaction between drilling fluids and shale has been a challenge due to the complexity of both the physical and chemical variations in shale formations. This paper presents some of the primary laboratory and wellsite testing techniques that are often used by mud engineers to characterize and remediate drilling fluids and shale interactions. Well-preserved core samples retrieved from the Zubair shale formation in Southern Iraq were run through extensive testing to describe the special characterization of the Zubair shale. These characteristics were measured and described, including the structure, texture, mineralogy, and reactivity, using a scanning electron microscope (SEM), a thin-section photograph, X-ray diffraction analysis (XRD) imaging, and cation exchange capacity (CEC) analysis. Moreover, a capillary suction timer (CST), hot rolling dispersion test, bulk hardness test, linear swell meter (LSM), and fracture development test were used to evaluate the stability of shale in the presence of test fluids. The test fluids included fresh water, 20 wt% NaCl brine, 7 wt% KCl brine, and a combination of 7 wt% KCl and 3 vol% glycol. The results illustrated that the Zubair shale is composed mainly (average content of 51.46%) of brittle minerals (i.e., quartz and calcite), along with 43.54% of clay minerals. The predominant clay minerals were kaolinite and illite, with an average content of 48.06% and 34.71%, respectively. In addition, the cation exchange capacity analysis and capillary suction time test indicated that Zubair shale has a low-to-moderate reactivity with drilling fluids. Furthermore, among the fluid systems tested, the best shale inhibition was achieved when the 7 wt% KCl and 3 vol% glycol solution was used. Shale sample analyses methods were used to understand the geologic features of the Zubair shale formations and to achieve a better perspective on the potential interactions of shale formations with drilling fluids. Understanding the properties and responses of shale formations to fluids is a significant step in achieving the chemical clay stabilization objectives. Proper design of drilling fluids, with appropriate mud weight and suitable additives, can lead to substantial cost reduction in drilling operations.

Corrigendum: Saliniramus fredricksonii gen. nov., sp. nov., a heterotrophic halophile isolated from Hot Lake, Washington, a member of a novel lineage (Salinarimonadaceae fam. nov.) within the order Rhizobiales, and reclassification of the genus Salinarimonas Liu et al. 2010 into Salinarimonadaceae

There was an error in the proposed genus name in the published article, in that the genus 'Salinivirga' was effectively published while this article was in review. Therefore, the genus 'Salinivirga' should be replaced with 'Saliniramus'. For the convenience of future readers, we have included the complete corrected article below, in which all occurrences of the incorrect genus name have been amended: A halophilic bacterial strain, HL-109T, was isolated from the unicyanobacterial consortium UCC-O, which was obtained from the photosynthetic mat of Hot Lake (Washington, USA). A polyphasic approach using phenotypic, genotypic and chemotaxonomic data was used to classify the strain within the order Rhizobiales. The organism stained Gram-negative and was a moderate thermophile with a growth optimum of 45 °C. It was obligately aerobic, heterotrophic and halophilic, growing in both NaCl and MgSO4 brines. The novel isolate had a polymorphic cellular morphology of short rods with occasional branching, and cells were monotrichous. The major fatty acids detected were C18 : 1, C18 : 0, C16 : 0 and C18 : cyc. Phylogenetic analysis of the 16S rRNA gene placed the strain in the order Rhizobiales and it shared 94 % identity with the type strain of its nearest relative, Salinarimonas ramus. Morphological, chemotaxonomic and phylogenetic results did not affiliate the novel organism with any of the families in the Rhizobiales; therefore, HL-109T is representative of a new lineage, for which the name Saliniramus fredricksonii gen. nov., sp. nov. is proposed, with the type strain HL-109T (=JCM 31876T=DSM 102886T). In addition, examination of the phylogenetics of strain HL-109T and its nearest relatives, Salinarimonas ramus and Salinarimonasrosea, demonstrates that these halophiles form a clade distinct from the described families of the Rhizobiales. We further propose the establishment of a new family, Salinarimonadaceae fam. nov., to accommodate the genera Saliniramus and Salinarimonas (the type genus of the family).

Micro-mechanics based numerical simulation of NaCl brine induced mechanical strength deterioration of sedimentary host-rock formations

Artificial fracture stimulation in low-grade sedimentary ore deposits is one method to improve mineral extraction efficiency of In-Situ Leaching (ISL) process. Low to moderate saline environments are found in most sedimentary ore deposits that deteriorate intact rock strength over time. It is important to recognize the host rock strength properties prior to artificial fracture stimulation. Therefore, to identify the effect of salinity on the mechanical properties of brine-saturated sandstone, a series of uniaxial compressive strength (UCS) tests and Brazilian tensile strength tests were performed on specimens saturated with water, and with varying NaCl brine concentrations (5.0%, 7.5%,10% and 12.5%). Scanning electron microscopy and inductively coupled plasma mass spectrometry (ICP-MS) tests reveal that increasing salinity deteriorate the mechanical integrity of sandstone by accelerated clay mineral dissolution. Consequently, 12.5% saturation fluid salinity resulted in a 40% reduction in UCS, 22% reduction in Young's modulus and 33% reduction in tensile strength. The strength deterioration observed in the experimental study was then successfully simulated using Particle Flow Code 3D (PFC3D) in consideration of the bond strength deterioration mechanism for sandstone. The calibrated model was used to accurately replicate the damage mechanism of sandstone under the influence of brine saturation. The model forms an accurate intact rock assembly for numerical modelling of saline sedimentary host-rock formations.

Emulsification of Athabasca bitumen by organic alkali: Emulsion phase behavior and viscosity for bitumen/brine/triethylenetetramine

Recovery of bitumen commonly uses steam assisted-gravity drainage, in which water throughput is intrinsically high. A large amount of condensed water near thermal fronts tends to substantially decrease the effective permeability to bitumen in the conventional gravity drainage process. This research investigates a potential way to use the condensed-water phase as an effective carrier for bitumen by making oil-in-water (o/w) emulsion. The expected mechanism depends on emulsification of bitumen into the water phase by natural surfactants that are generated through reactions of acidic oil components with organic alkali.The main objective of this paper is to study the ability of an organic alkali to create o/w emulsions that are much more mobile than the original bitumen. Triethylenetetramine (TETA) was selected as organic alkali for this paper with no other additives. The main contribution of this paper is a new set of experimental data (phase behavior and viscosities) for emulsions for mixtures of Athabasca bitumen, TETA, and NaCl brine at a wide range of alkali concentrations, salinities, and water-to-oil ratios (WORs) at temperatures up to 373 K.Results show that the o/w emulsions created by TETA can be an effective bitumen carrier with a low viscosity and high bitumen content in the emulsion. It is possible to create o/w emulsions by adding a small amount of TETA to Athabasca bitumen and NaCl brine. Single-phase o/w emulsions, which are desirable as a bitumen carrier, were observed for TETA concentrations below 5.0 wt% at salinities 0 ppm and 1000 ppm at 373 K. The bitumen content in o/w emulsion was the highest for 2.0 wt% TETA samples, and it increased with increasing temperature. In comparison to the original bitumen, o/w emulsions were 4–5 orders of magnitude less viscous at 298 K, 2 to 3 orders of magnitude less viscous at 323 K, and 1 to 2 orders of magnitude less viscous at 353 K.

Phase Behavior and Raman Spectroscopic Analysis for CH4 and CH4/C3H8 Hydrates Formed from NaCl Brine and Monoethylene Glycol Mixtures

We present pure CH4 and CH4/C3H8 mixed hydrate phase equilibria formed from a mixture of NaCl (10 wt %) and monoethylene glycol (MEG, 10 and 30 wt %) solutions. As expected for thermodynamic inhibitors, the mixture of salt and glycol causes the hydrate phase equilibrium boundary to shift to lower temperatures and higher pressures, and on increasing the MEG concentration, the hydrate stable region shifted more. The measured experimental data are also compared with a thermodynamic model recently developed, named the Hu–Lee–Sum correlation, showing that the data match well with the predictions. The experimental data were used to calculate the enthalpy of hydrate dissociation. The enthalpies of CH4 hydrates in the mixture of 10 wt % NaCl brine and 10 or 30 wt % MEG were found to be ∼58.7 and 54.63 kJ/mol, respectively, corresponding to structure I hydrates, whereas for the CH4/C3H8 (91.98:8.02 mol %) mixed gas system, the enthalpies of dissociation were found to be ∼101.10 kJ/mol (10 wt % NaCl + 10 wt % MEG) ...

Semi-Empirical Model to Estimate the Solubility of CO2 NaCl Brine in Conditions Representative of CO2 Sequestration

CO2 sequestration is considered as one of the most anticipated methods to mitigate CO2 concentration in the atmosphere. Solubility mechanism is one of the most important and sophisticated mechanisms by which CO2 is rendered immobile while it is being injected into aquifers. A semi-empirical, easy to use model was developed to calculate the solubility of CO2 in NaCl brines with thermodynamic conditions (pressure, temperature) and salinity gradients representative CO2 sequestration in the Malay basin. The model was compared to the previous more sophisticated models and a good consistency was found among the data obtained using the two models. A Sensitivity analysis was also conducted on the model to test its performance beyond its limits.

As Green As It Gets: An Abundant Kinetic Hydrate Inhibitor from Nature

We report the development of a kinetic hydrate inhibitor (KHI) based on a cheap, abundantly available natural product that is readily biodegradable and low in toxicity. The optimal product, called KHI530, was determined using KHI screening tests by the slow constant cooling method in multiple rocking cells. The performance was better than a low molecular weight poly(N-vinylpyrrolidone) for a synthetic natural gas mixture (SNG) forming primarily structure II hydrate and about the same performance for structure I methane hydrate. Isothermal tests using the SNG mixture indicate that an active dosage of 0.5 wt % can protect against hydrate formation for 48 h at a subcooling of 6–7 °C. KHI530 exhibits no cloud point up to 95 °C in deionized water or NaCl brines up to 7 wt %. KHI530 can be biostabilized in monoethylene glycol (MEG) or using a biocide such as tetrahydroxymethylphosphonium sulfate (THPS), which does not affect the KHI performance. KHI530 was found to be fully compatible at all ratios with thermod...

Histological Study of Ultrastructural Changes in Muscle Exposed to Various Concentrations of NaCl Brine.

Knowledge on the relationship between NaCl concentration, in situ structural changes and transfers of salt-extracted proteins can be usefully mobilized to reduce sodium content in cured meat products.

Corrosion Protection of Pipeline Interior Surface By Sacrificial Metal Coatings in a Natural Gas Environment

While corrosion protection of the exterior of natural gas pipeline has developed to be a routine process, including use of coatings and cathodic impressed current systems; the protection of the inside of the pipe is not as straightforward. This work explores the use of sacrificial metal coatings to protect the pipes inner surface. Coatings, applied by techniques including hot dip, electroplated, and thermally spray, were applied to one side of low carbon steel plates which were similar in composition to an API 5L pipeline steel. Coatings evaluated included Zn, alloys of Zn (95 Zn-5 Al, 85 Zn- 15 Al), Al, and an alloy of 95 Al- 5 Mg. Existing models suggest that any residual water, which often contains chlorides and CO2 from the gas, will be the primary contributors to any corrosion. Gravimetric corrosion tests were conducted in autoclaves to simulate the partial pressure of CO2 found in a natural gas pipeline. A test condition of; immersed samples in a 3 ½ wt. % NaCl brine, with a pressure of 300 kPa (45 psig) of CO2, and a temperature of 40 °C; was used. Tests of 168 h duration with, and without, a nonconductive masking of the steel substrate were conducted. For the tests where the steel surfaces were exposed, on the back side of the coated side of the steel test coupons, did not show significant corrosion after the tests with any of the sacrificial coatings. For the Zn, or Zn alloy, samples; a layer of ZnCO3 formed on coated and uncoated steel surfaces. The results indicated that for these conditions, the thermally sprayed coatings showed less weight loss than the hot dipped or electroplated coatings, and the Zn alloy with 15% Al had less weight loss than either the pure Zn or the Zn with 5 % Al. Visual examination indicated that while AlMg alloy successfully protected the uncoated steel from corrosion, it showed heavy corrosion including pitting in these conditions.

Effects of selected bacterial cultures on safety and sensory traits of Nocellara Etnea olives produced at large factory scale

This work investigates the effects of different combinations of selected lactic acid bacteria strains on Lactobacillus species occurrence, on safety and on sensory traits of natural green table olives, produced at large factory scale. Olives belonging to Nocellara Etnea cv were processed in a 6% NaCl brine and inoculated with six different bacterial cultures, using selected strains belonging to Lactobacillus plantarum, Lactobacillus paracasei and Lactobacillus pentosus species.The fermentation process was strongly influenced by the added starters and the identification of lactic acid bacteria isolated throughout the process confirms that L. pentosus dominated all fermentations, followed by L. plantarum, whereas L. casei was never detected. Pathogens were never found, while histamine and tyrosine were detected in control and in two experimental samples. The samples with the lowest final pH values showed a safer profile and the most appreciated sensory traits.The present study highlights that selected starters promote prevalence of L. pentosus over the autochthonous microbiota throughout the whole process of Nocellara Etnea olives.

Salinivirga fredricksonii gen. nov., sp. nov., a heterotrophic halophile isolated from a photosynthetic mat, a member of a novel lineage (Salinarimonadaceae fam. nov.) within the order Rhizobiales, and reclassification of the genus Salinarimonas Liu et al. 2010 into Salinarimonadaceae.

A halophilic bacterial strain, HL-109T, was isolated from the unicyanobacterial consortium UCC-O, which was obtained from the photosynthetic mat of Hot Lake (Washington, USA). A polyphasic approach using phenotypic, genotypic and chemotaxonomic data was used to classify the strain within the order Rhizobiales. The organism stained Gram-negative and was a moderate thermophile with a growth optimum of 45 °C. It was obligately aerobic, heterotrophic and halophilic, growing in both NaCl and MgSO4 brines. The novel isolate had a polymorphic cellular morphology of short rods with occasional branching, and cells were monotrichous. The major fatty acids detected were C18 : 1, C18 : 0, C16 : 0 and C18 : cyc. Phylogenetic analysis of the 16S rRNA gene placed the strain in the order Rhizobiales and it shared 94 % identity with the type strain of its nearest relative, Salinarimonas ramus. Morphological, chemotaxonomic and phylogenetic results did not affiliate the novel organism with any of the families in the Rhizobiales; therefore, HL-109T is representative of a new lineage, for which the name Salinivirga fredricksonii gen. nov., sp. nov. is proposed, with the type strain HL-109T (=JCM 31876T=DSM 102886T). In addition, examination of the phylogenetics of strain HL-109T and its nearest relatives, Salinarimonas ramus and Salinarimonasrosea, demonstrates that these halophiles form a clade distinct from the described families of the Rhizobiales. We further propose the establishment of a new family, Salinarimonadaceae fam. nov., to accommodate the genera Salinivirga and Salinarimonas (the type genus of the family).

EFFECT OF DIFFERENT STORAGE CONDITIONS ON THE SHELF LIFE OF NATURAL GREEN TABLE OLIVES

The aim of this research is to study the effects of different storage conditions on Spanish (alkaline debittering) and natural (directly brined) green olives. Laboratory-processed olives were stored in 6% brine or in a vacuum bag without brine, at 6 or 20°C. After 18 months, natural olives showed higher microbial and olive oil stability than NaOH-treated olives. The lower pH (<4.80) and higher total phenol content (0.2 g/100 g wet pulp) influenced positively the long shelf life of natural olives. The packaging in 6% NaCl brine and in a vacuum bag stored at 20°C gave better performance, while growth of psychrophilic spoilage bacteria occurred at cold temperature.

Effect of brine composition on oil-rock interaction by atomic force microscopy

Wettability alteration is known to occur in low salinity waterflooding of carbonate rocks. Oil droplets are thought to detach from the rock partially due to changes of the solid surface charge by multi-ion exchange with the brine. These mechanisms have been investigated in the past by measuring zeta potentials of calcite and oil, separately in test brines. In this work, the coupled calcite-brine-oil system was studied by measuring the adhesion force of an organic acid functionalized solid probe with a calcite surface, using an atomic force microscope. Brine compositions were varied in pH and ion concentration, to identify key conditions for minimum oil adhesion to calcite. Our experiments showed the strongest acid-calcite adhesion in formation brine. The adhesion force decreased in decreasing ionic strength NaCl brines, particularly below ∼0.1 mol/L where the diffuse double layer expanded greatly. The complex composition brines of ultra-dilute seawater and excess sulfate seawater each gave the lowest adhesion due to a combination of double layer expansion, surface charge change and gypsum passivation of the calcite surface. Modifying seawater's Ca2+ and Mg2+ concentrations showed little change in the adhesion force despite being potential determining ions for calcite. Adhesion force responded the most to pH change. Increasing pH substantially decreased the adhesion force in seawater and excess sulfate seawater until a threshold value of pH 10. Above pH 10, the adhesion increased due to brine instability (to mineral precipitation) and material precipitation onto the calcite surface.

Automatic dispersion, long-term stability of multi-walled carbon nanotubes in high concentration electrolytes

Nanoparticles have been known as the useful materials in working fluids for petroleum industry. But the stabilization of nano-scaled materials in water-based working fluids at high salinities is still a big challenge. In this study, we successfully prepared the anionic polymer/multi-walled carbon nanotubes (MWNTs) composites by covalently wrapping of MWNTs with poly (sodium 4-styrenesulfonate) (PSS) to improve the stability of MWNTs in high concentration electrolytes. The PSS/MWNTs composites can automatically disperse in salinity up to 15 wt% NaCl and API brines (8 wt% NaCl + 2 wt% CaCl2). Hydrodynamic diameters of composites were measured as a function of ionic strength and API brines by dynamic light scattering (DLS). By varying the concentration of brines, hydrodynamic diameter of PSS/MWNTs composites in brines fluctuated between 545 ± 110 nm for 14 days and 673 ± 171 nm for 30 days. Above results showed that PSS/MWNTs could be well stable in high salts solutions for a long period of time. After wrapped with PSS, the diameters of nanotubes changed from 30 ~ 40 to ~ 430 nm, the thickness of wrapped polymer is about ~ 400 nm by analysis of morphologies. The zeta potentials of PSS/MWNTs composites in various salinity of brines kept at approximately − 41 ~ − 52 mV. Therefore, the well dispersion of PSS/MWNTs in high salinity is due to large negative charges of poly (sodium 4-styrenesulfonate), which provide enough electrostatic repulsion and steric repulsion to hinder compression of electric double layer caused by high concentration electrolytes.

Evolution of Yeast Consortia during the Fermentation of Kalamata Natural Black Olives upon Two Initial Acidification Treatments.

The objective of this study was to elucidate the yeast consortia structure and dynamics during Greek-style processing of Kalamata natural black olives in different brine solutions. Olives were subjected to spontaneous fermentation in 7% (w/v) NaCl brine solution (control treatment) or brine acidified with (a) 0.5% (v/v) vinegar, and (b) 0.1% (v/v) lactic acid at the onset of fermentation. Changes in microbial counts, pH, acidity, organic acids, sugars, and alcohols were analyzed for a period of 187 days. Yeast consortia diversity was evaluated at days 4, 34, 90, 140, and 187 of fermentation. A total of 260 isolates were characterized at sub-species level by rep-PCR genomic fingerprinting with the oligo-nucleotide primer (GTG)5. The characterization of yeast isolates at species level was performed by sequencing of the D1/D2 domain of 26S rRNA gene. Results showed that yeasts dominated the process presenting a relatively broad range of biodiversity composed of 11 genera and 21 species. No lactic acid bacteria (LAB) or Enterobacteriaceae could be enumerated after 20 and 10 days of fermentation, respectively. The dominant yeast species at the beginning were Aureobasidium pullulans for control and vinegar acidification treatments, and Candida naeodendra for lactic acid treatment. Between 34 and 140 days the dominant species were Candida boidinii, Candida molendinolei and Saccharomyces cerevisiae. In the end of fermentation the dominant species in all processes were C. boidinii and C. molendinolei, followed by Pichia manshurica and S. cerevisiae in lactic acid acidification treatment, P. manshurica in vinegar acidification treatment, and Pichia membranifaciens in control fermentation.

The effect of seasoning with herbs on the nutritional, safety and sensory properties of reduced-sodium fermented Cobrançosa cv. table olives

This study aimed at evaluating the effectiveness of seasoning Cobrancosa table olives in a brine with aromatic ingredients, in order to mask the bitter taste given by KCl when added to reduced-sodium fermentation brines. Olives were fermented in two different salt combinations: Brine A, containing 8% NaCl and, Brine B, a reduced-sodium brine, containing 4% NaCl + 4% KCl. After the fermentation the olives were immersed in seasoning brines with NaCl (2%) and the aromatic herbs (thyme, oregano and calamintha), garlic and lemon. At the end of the fermentation and two weeks after seasoning, the physicochemical, nutritional, organoleptic, and microbiological parameters, were determined. The olives fermented in the reduced-sodium brines had half the sodium concentration, higher potassium and calcium content, a lower caloric level, but were considered, by a sensorial panel, more bitter than olives fermented in NaCl brine. Seasoned table olives, previously fermented in Brine A and Brine B, had no significant differences in the amounts of protein (1.23% or 1.11%), carbohydrates (1.0% or 0.66%), fat (20.0% or 20.5%) and dietary fiber (3.4% or 3.6%). Regarding mineral contents, the sodium-reduced fermented olives, presented one third of sodium, seven times more potassium and three times more calcium than the traditional olives fermented in 8% NaCl. Additionally, according to the panelists’ evaluation, seasoning the olives fermented in 4% NaCl + 4% KCl, resulted in a decrease in bitterness and an improvement in the overall evaluation and flavor. Escherichia coli and Salmonella were not found in the olives produced.

Streaming Potential Coupling Coefficient and Transport Properties of Unsaturated Carbonate Rocks

Core Ideas Streaming potential coupling coefficient is dependent on saturation in carbonate rocks. Salinity influences the streaming potential coupling coefficient. Water relative permeability can be estimated from streaming potential measurements. Transport properties of carbonate rocks can be modeled using the van Genuchten approach. We measured the streaming potential coupling coefficient of natural saturated and unsaturated carbonate rocks. Saturation was achieved with NaCl brines with salinities ranging from 2 × 10−3 to 2.0 mol L−1. The magnitude of the coupling coefficient increased with decreasing salinity, similarly to the trend observed for sandstones. The permeability had a low impact on the values of the streaming potential coupling coefficient at high and low salinity. The zeta potential was calculated at full saturation using a modified version of the Helmholtz–Smoluchowski equation that accounts for surface electrical conductivity. Under atmospheric conditions, the magnitude of the zeta potential decreased with the increase in salinity. We also explored the relationships between the streaming potential coupling coefficient and water saturation in three partially saturated limestones using a steady‐state flow experiment. We found good agreement between the van Genuchten approach and experimental data, and fitted both the relative permeability and capillary pressure curves with the same value of the van Genuchten exponent mv. We validated the predictive water relative permeability model described by Revil in water‐wet rocks when the second fluid phase is non‐polar.

Perchlorate-Coupled Carbon Monoxide (CO) Oxidation: Evidence for a Plausible Microbe-Mediated Reaction in Martian Brines.

The presence of hydrated salts on Mars indicates that some regions of its surface might be habitable if suitable metabolizable substrates are available. However, several lines of evidence have shown that Mars’ regolith contains only trace levels of the organic matter needed to support heterotrophic microbes. Due to the scarcity of organic carbon, carbon monoxide (CO) at a concentration of about 700 parts per million (about 0.4 Pa) might be the single most abundant readily available substrate that could support near-surface bacterial activity. Although a variety of electron acceptors can be coupled to CO oxidation, perchlorate is likely the most abundant potential oxidant in Mars’ brines. Whether perchlorate, a potent chaotrope, can support microbial CO oxidation has not been previously documented. We report here the first evidence for perchlorate-coupled CO oxidation based on assays with two distinct euryarchaeal extreme halophiles. CO oxidation occurred readily in 3.8 M NaCl brines with perchlorate concentrations from 0.01 to 1 M. Both isolates were able to couple CO with perchlorate or chlorate under anaerobic conditions with or without nitrate as an inducer for nitrate reductase, which serves as a perchlorate reductase in extreme halophiles. In the presence of perchlorate, CO concentrations were reduced to levels well below those found in Mars’ atmosphere. This indicates that CO could contribute to the survival of microbial populations in hydrated salt formations or brines if water activities are suitably permissive.

The influence of NaCl concentration of brine and different packaging on goat white brined cheese characteristics

Goat white brined cheese was ripened at 13–15 °C for 10 days in 6% and 3% (w/v) NaCl brine, and stored refrigerated under modified atmosphere (MAP; 60% CO2 and 40% N2) or vacuum for 40 days. Cheeses stored in brine were taken as control samples. Salt reduction lowered consumer acceptability of cheeses, with 3% NaCl MAP cheese having the lowest score for overall quality. It also changed texture profile of cheese, mainly by increasing its cohesiveness. The MAP packaging inhibited the growth of psychrotrophic bacteria and yeasts/moulds over the period of examination. The brine-stored cheeses had decreased dry matter and total protein content and their ripening index was significantly lower in comparison with vacuum and MAP stored cheeses. According to the patterns of electrophoresis, packaging had no notable effect on proteolysis. Regardless of the factors applied, the colour of cheese remained visually unchanged.

Flow characteristics of coarse particles in horizontal hydraulic conveying

In hydraulic conveying of solid particles, the flow characteristics play a significant rule on choosing the optimal operating conditions for a desired conveying rate. The main goal of this study is to investigate the flow characteristics in terms of essential operating conditions. For this target 3D CFD-DEM simulations were held to provide information on the hydraulic conveying of coarse particles in a fully developed horizontal flow in a pipe. The simulation was done in a periodic pipeline which was validated with experimental data and showed good agreements for the pressure and concentration profile. Therefore, the modeling and the simulation setup, which are given in this study, can be used as a basis for further investigating this phenomenon. To examine the effects of the operating conditions on the flow, a parametric study was done using NaCl particles and brine as the carrier. This investigation included running several simulations and changing the operating conditions: mean fluid velocity, particle concentration, particle size and pipe size. The results were analyzed to retrieve the pressure drop, the velocity profiles of the phases, the concentration profiles, the turbulent intensity, the delivered concentration and the dominant forces. By analyzing these results, we found how the flow pattern is governed by the operating conditions. In particular, an interesting aspect that found is that in the mean velocity range of 0.6–4m/s two regimes dominated the flow, below (moving bed) and above the velocity of 1.5m/s (heterogeneous flow). Furthermore, it is found that the inter-particle collisions are the most dominant effect that support the suspended particles above the bed, which suggest that flow eddies have less significance in that manner.