Particle Viscosity Research Articles

Burst-by-Burst Measurement of Rotational Diffusion at Nanosecond Resolution Reveals Hot-Brownian Motion and Single-Chain Binding.

We record dark-field scattering bursts of individual gold nanorods, 52 × 15 nm2 in average size, freely diffusing in water suspension. We deduce their Brownian rotational diffusion constant from autocorrelation functions on a single-event basis. Due to spectral selection by the plasmonic resonance with the excitation laser, the distribution of rotational diffusion constants is much narrower than expected from the size distribution measured by TEM. As rotational diffusion depends on particle hydrodynamic volume, viscosity, and temperature, it can sense those parameters at the single-particle level. We demonstrate measurements of hot Brownian rotational diffusion of nanorods in temperature and viscosity gradients caused by plasmonic heating. Further, we monitor hydrodynamic volumes of gold nanorods upon addition of very low concentrations of the water-soluble polymer PVA, which binds to the particles, leading to measurable changes in their diffusion constant corresponding to binding of one to a few polymer coils. We propose this analysis technique for very low concentrations of biomolecules in solution.

Characterization of ultrasonicated assisted encapsulated omega 3 fatty acids and inulin for food applications

The paper deals with development of emulsion with special features such as omega-3 fatty acids derived from plant sources and inulin as a core material employing whey protein concentrate, & maltodextrin as wall material as a medium of fortificant. Amongst different combinations of tested amplitude and time of ultrasonication, optimized emulsion exhibited no signs of oil separation until 60 days, when kept under ambient and refrigerated storage conditions. Parameters such as particle size (nm), polydispersity index, zeta potential, and viscosity were helpful to form stable emulsion by means of ultrasonic processor. The optimized emulsion contained Dietary fibre content (7.40%); Alpha linolenic acid, (5.35%); Eicosapentaenoic acid (0.56%) and Docosahexaenoic acid (0.75%). To improve the shelf life, the shelf-stable emulsion was subjected to spray drying process to obtain encapsulated powder by optimizing the inlet and outlet temperature as 160 °C and 80 °C, respectively, for the retention of nutraceuticals. Powder demonstrated the presence of Alpha Linolenic Acid (ALA), Eicosapentaenoic acid (EPA), and Docosahexaenoic acid (DHA) @17.8, 1.82, & 1.95% respectively with 95.61% encapsulation efficiency. Bioavailability studies subjected to mimic human gastric and intestinal conditions, paved the way to further food applications which may confer health benefits in the human systems.

Liquid-assisted irregular coarse particle fluidization in a fluidized bed flotation cell: Bed of low-density versus high-density particles

Fluidization can enhance coarse particle separation. Here, a three-dimensional computational fluid dynamics (CFD) modeling in a fluidized bed flotation cell is performed to explore the complex insights of coarse irregular particle fluidization behaviours. To address the irregular property of the particle, the classical drag model is modified by incorporating the particle’s shape factor. Simulated particle volume fraction results and experimental data using a fluidized bed flotation cell showed that the irregular particle drag models had a relative error of 3.9% which was significantly better than that of the spherical particle drag models. Thereafter, the CFD model was applied to investigate the bed of low-density irregular coarse particles, 1600 kg/m3, and high-density irregular coarse particles, 2800 kg/m3, at low and high fluidization liquid velocities. It was shown that around 1.7-fold increased density of particles and liquid fluidization velocity increased the bed expansion height roughly 1.8-fold. The time-averaged pressure, volume fraction, apparent viscosity, and velocity of particles are analyzed to explore the fluidization behaviours, particularly within the free settling regime, plug-flow regime, and dewatering zone in the fluidized bed flotation cell. There was a higher apparent viscosity in the dewatering zone than in the plug-flow mixing zone, while the highest apparent viscosity was found in the free settling zone. The outcomes of these CFD studies are significant for the flotation of coarse particles in fluidized beds.

Physicochemical properties of soybean protein isolate-based gel produced through probiotic fermentation

Soy protein isolate (SPI) was used to prepare gels through probiotic fermentation. The effects of fermentation time (0–20 h) on the physicochemical properties of resulting gel were evaluated. The effect of probiotic fermentation on physicochemical properties of gel was found to highly depend on the fermentation time. The probiotic fermentation decreased the pH value below pH 4.75 and this process also induced SPI to form a gel upon 10 h. The formation of gel was indicated by the increase of particle size, viscosity and storage modulus, and appearance of a new peak in molecular weight distribution. The formation of porous and gel-like microstructure, due to the aggregation of SPI molecules, also occurred after 10 h of fermentation. Water holding capacity of SPI-based gel reached the highest value at 15 h fermentation and decreased with further fermentation. The probiotic fermentation caused an increase of band intensity of amide-A in FTIR spectra. It also caused a decrease of surface hydrophobicity and fluorescence intensity in intrinsic tryptophan fluorescence spectra. The subunits of SPI remained intact and were not affected by probiotic fermentation.

Physical-chemical properties and tribological characterization of water-glycerine based metal oxide nanofluids

Nanofluids have been recently used in minimum quantity lubrication (MQL) applications to counteract the disadvantages of conventional cooling lubrication. However, comparative investigations of different types of metal oxide particles, their corresponding nanofluids, and their application in tribological tests to assess their usability as MQL-cutting fluids in machining is still in research. The technical application of those fluids is hindered by the lack of combined knowledge regarding the physical-chemical properties and their corresponding behavior as cutting fluids. Therefore, in this research, Al2O3, ZrO2 and TiO2 nanoparticles are added in different concentrations to base fluids to form water-glycerine-based nanofluids. The fluids were investigated regarding their physical-chemical properties such as particle distribution and viscosity and applied in tribological experiments to elaborate wear and particle deposition on steel workpieces. The influence of physical-chemical properties on the corresponding surfaces after tribological treatment was evaluated by scanning electron microscope imaging of the processed specimen. By varying the water-in-glycerine concentration, the often neglected viscosity increase of base fluid to mixed fluid was considered revealing a stronger influence of particle presence compared to viscosity increase caused by nanoparticle addition.

Influence of Calcium-Sequestering Salts on Heat-Induced Changes in Blends of Skimmed Buffalo and Bovine Milk.

Heat-induced interactions of calcium and protein in milk lead to undesirable changes in the milk, such as protein coagulation, which can be minimized through the addition of calcium-sequestering salts prior to heat treatment. Thus, the present study investigated the influence of 5 mM added trisodium citrate (TSC) or disodium hydrogen phosphate (DSHP) on the heat-induced (85 °C and 95 °C for 5 min) changes in physical, chemical, and structural properties of buffalo and bovine skim milk mixtures (0:100, 25:75, 50:50, 75:25, and 100:0). Significant changes in pH and calcium activity as a result of TSC or DSHP addition subsequently resulted in higher particle size and viscosity as well as non-sedimentable protein level. These changes are mostly observed during heat treatment at 95 °C and increased proportionally to the concentration of buffalo skim milk in the milk mixture. Significant changes were affected by TSC addition in the 75:25 buffalo:bovine milk blend and buffalo skim milk, but for other milk samples, TSC addition effected comparable changes with DSHP addition. Overall, the addition of TSC or DSHP before heat treatment of buffalo:bovine milk blends caused changes in milk properties that could reduce susceptibility of milk to coagulation.

Stability and Digestive Properties of a Dual-Protein Emulsion System Based on Soy Protein Isolate and Whey Protein Isolate.

The stability and digestive properties of a dual-protein emulsion consisting of soy protein isolate (SPI) and whey protein isolate (WPI) have been systematically studied. The results showed that the particle size and viscosity of the dual-protein emulsion system decreased continuously with the increase in WPI, and this might be related to the large amount of electric charge on the surface of the emulsion droplets. Dual-protein emulsions with ratios of 3:7 and 5:5 showed the highest emulsion activity, while emulsion stability increased with the increase in WPI. The thicker adsorption layer formed at the interface might have contributed to this phenomenon. After in-vitro-simulated digestion, the emulsion droplet particle size increased substantially due to the weakened electrostatic repulsion on the droplet surface, especially for the intestinal digestion phase. Meanwhile, WPI accelerated the release of free fatty acids in the digestion process, which played a positive role in the nutritional value of the dual-protein emulsion. In accelerated oxidation experiments, WPI also improved the antioxidant properties of the dual-protein emulsion system. This study will provide a new insight and necessary theoretical basis for the preparation of dual-protein emulsions.

Effects of monoacylglycerols with different saturation degrees on physical and whipping properties of milk fat-based whipping creams.

Milk fat-based whipping cream is primarily comprised of cream and whole milk. It has melt-in-the-mouth texture and unique milk flavor. However, milk fat-based whipping cream suffers from poor emulsion stability and foam firmness. The effects of monoacylglycerols (MAGs) with different saturation degrees (M1: 98% saturation, M2: 70% saturation and M3: 30% saturation) on emulsion properties (average particle size, viscosity, and emulsion stability) and whipping properties (overrun, firmness, shape retention ability, and foam stability) of milk fat-based whipping creams were investigated in this study. MAGs significantly decreased particle sizes (from 2.84 to 1.16μm) and enhanced viscosity (from 350 to 490cP) of the milkfat-based emulsions (emulsion without MAGs: M0, 5.01μm, 298cP) (P < 0.05). MAGs increased the stability of the milk fat-based emulsions with lesser phase separation during centrifugation tests and lower changes in particle sizes and viscosities during temperature cycling tests. Emulsion M1 with highest degree of saturation is less likely to destabilize and phase inverse. The decrease sharply in conductivity can be attributed to the entrapment of large amounts of air. Following that, the conductivity of M1 with low variation indicating high whipping resistance and less likely to coalescence and phase separation. Adding MAGs can significantly enhance overrun (M1: 205.3%, M2: 198.5%, M3: 141.4%) as compared to the control sample (M0: 97.9%) (P < 0.05). In emulsions containing MAGs with high degree of saturation (M1 and M2), firmness (M1: 95g, M2: 109g) and shape retention ability of the whipped creams were reduced as compared to control emulsion without MAG (M0: 173g), but the foam stability (M1: 89%, M2: 91%) was enhanced (M0: 81%); M3 (firmness: 507g; foam stability: 66%) has the contrasted effects. Whipping cream M2 demonstrated the best whipping properties with high overrun (198.46%), good firmness (109g), shape retention ability and foam stability (91%). Good quality whipping creams can be obtained by selecting suitable MAGs.

Effects of fermentation with Kefir grains on nutrient composition, flavor volatiles, and product physical stability of a hemp seed (Cannabis sativa L.) beverage

This study investigated the effects of fermentation with kefir grains on the nutritional composition, flavor, and physical stability of hemp seed, and explored its potential as a probiotic plant-based beverage. After fermentation of a homogenized hemp seed water suspension, the concentrations of organic acids (lactic, acetic, tartaric, butyric, succinic, and malic acids) increased. The content of nutritional components, amino acids, and free fatty acids increased, as well as the number (from 16 to 21) and concentrations of flavor compounds, such as alcohols, acids, and esters. Fermentation also increased the particle size, viscosity, and phase-separation resistance of the final product. Therefore, kefir grains improved the nutritional composition, flavor, and physical stability of the hemp seed beverage, indicating its potential as a functional beverage, and providing a theoretical basis for the development of plant-based fermented beverages.

Aqueous cannabidiol β-cyclodextrin complexed polymeric micelle nasal spray to attenuate in vitro and ex vivo SARS-CoV-2-induced cytokine storms

Cannabidiol (CBD) has a number of biological effects by acting on the cannabinoid receptors CB1 and CB2. CBD may be involved in anti-inflammatory processes via CB1 and CB2 receptors, resulting in a decrease of pro-inflammatory cytokines. However, CBD's poor aqueous solubility is a major issue in pharmaceutical applications. The aim of the present study was to develop and evaluate a CBD nasal spray solution. A water-soluble CBD was prepared by complexation with β-cyclodextrin (β-CD) at a stoichiometric ratio of 1:1 and forming polymeric micelles using poloxamer 407. The mixture was then lyophilized and characterized using FT-IR, DSC, and TGA. CBD-β-CD complex-polymeric micelles were formulated for nasal spray drug delivery. The physicochemical properties of the CBD-β-CD complex-polymeric micelle nasal spray solution (CBD-β-CDPM-NS) were assessed. The results showed that the CBD content in the CBD-β-CD complex polymeric micelle powder was 102.1 ± 0.5% labeled claim. The CBD-β-CDPM-NS was a clear colorless isotonic solution. The particle size, zeta potential, pH value, and viscosity were 111.9 ± 0.7 nm, 0.8 ± 0.1 mV, 6.02 ± 0.02, and 12.04 ± 2.64 cP, respectively. This formulation was stable over six months at ambient temperature. The CBD from CBD-β-CDPM-NS rapidly released to 100% within 1 min. Ex vivo permeation studies of CBD-β-CDPM-NS through porcine nasal mucosa revealed a permeation rate of 4.8 μg/cm2/min, which indicated that CBD was effective in penetrating nasal epithelial cells. CBD-β-CDPM-NS was tested for its efficacy and safety in terms of cytokine production from nasal immune cells and toxicity to nasal epithelial cells. The CBD-β-CDPM-NS was not toxic to nasal epithelial at the concentration of CBD equivalent to 3.125–50 μg/mL. When the formulation was subjected to bioactivity testing against monocyte-like macrophage cells, it proved that the CBD-β-CDPM-NS has the potential to inhibit inflammatory cytokines. CBD-β-CDPM-NS demonstrated the formulation's ability to reduce the cytokine produced by S-RBD stimulation in ex vivo porcine nasal mucosa in both preventative and therapeutic modes.

Addition of gelatin increased the spray drying performance of the Pickering emulsion stabilized by the ovalbumin – gum Arabic electrostatic complex

Gelatin was added to the perilla seed oil (PSO) Pickering emulsion stabilized by the ovalbumin (OVA) – gum Arabic (GA) electrostatic complex to increase its spray drying performance. The results indicated that the addition of gelatin to the primary PSO Pickering emulsion in mass ratio to the OVA – GA complex 1:1 before high-pressure homogenization could increase the total solid concentration of the feed to 20% and decrease the surface oil content of the resultant powder to 9.90% without compromising its total oil content (77.84%) and powder yield (76.08%) compared with that in the absence of gelatin. Characterization of the Pickering emulsions revealed that gelatin adsorbed to the surface of the primary emulsion droplets through electrostatic interaction and the subsequent high-pressure homogenization caused composition and structure rearrangement in the emulsion interface, leading to reduced particle size and viscosity of the secondary emulsion. The optimized PSO powder possessed excellent structural integrity according to scanning electron microscope observation as well as good flowability and water dispersibility. Hence, the addition of gelatin is an effective strategy to improve the economy for producing powders with ultra-high oil contents by spray drying Pickering emulsions stabilized by the OVA – GA electrostatic complex.

Particle Size Distribution and Its Impacts on Ash Deposition and Radiative Transfer during Oxy-Combustion of Rice Husk–Natural Gas

Rice husk (RH) co-combustion with natural gas in highly oxygen-enriched concentrations presents a net carbon-negative energy production opportunity while minimizing flue gas recycling. However, recent experiments have shown enhanced ash deposition rates in oxygen-enriched conditions, with deposition/shedding also being dependent on the particle size distribution (PSD) of the parent RH fuel. To uncover the causative mechanisms behind these observations, add-on models for ash deposition/shedding and radiative properties were employed in computational fluid dynamics simulations. The combustion scenarios investigated encompassed two types of RH (US RH, Chinese RH) with widely varying ash contents (by % mass) and inlet fuel PSD with air and O2/CO2 (70/30 vol %, OXY70) as oxidizers. Utilizing the measured fly-ash PSDs near the deposit surface and modeling the particle viscosity accurately, particle kinetic-energy (PKE)-based capture and shedding criteria were identified as the keys to accurate deposition/shedding rate predictions. The OXY70 scenarios showed higher ash-capturing propensities due to their lower PKE. Conversely, higher erosion rates were predicted in the AIR firing scenarios. In addition, the radiative characteristics across all the scenarios were dominated by the gases and were not sensitive to the fly-ash PSD. Therefore, the higher particle concentrations in the OXY70 conditions did not negatively impact the heat extraction.

Impact of bubble dynamics on aerosol transport based on CFD analysis

The fundamental process of submicron particle transport through a rising bubble is investigated based on the VOF-LPT method. Since the presence of particle interfacial behavior is generally disregarded in previous studies, an interfacial penetration model is applied in this work to include its effect on the scrubbing efficiency, whereby the process of how bubble dynamics affects aerosol transport is analyzed in detail via parametric studies including Eötvös and Galilei numbers. The results indicated that the dependence of the scrubbing efficiency on increasing Eötvös numbers is non-monotonic, which is linked to the weakened internal flow in the approaching process and the deteriorated surface tension force in the impacting process. By contrast, the decreasing Galilei numbers exert a trapping effect on submicron particles inside scrubbing bubbles, which is manifested as the dampened bubble shape oscillation in the approaching process and the escalated viscous drag in the impacting process. Aerosol removal contributions from different mechanisms are found to be highly dependent on gas-liquid surface tension but insensitive to liquid viscosity for submicron particles. In general, the present method is proven to be viable to simulate the submicron particle transport inside scrubbing bubbles under the circumstance of changeable bubble dynamics.

Effect of Different Lipid Ratios on Physicochemical Stability and Drug Release of Nanostructured Lipid Carriers Loaded Coenzyme Q10

Background: For treatment or skin care via topical route, Coenzyme Q10 needs to permeate the epidermis which it is practically insoluble in water and a high molecular weight that make it difficult to penetrate the skin. Nanostructured Lipid Carriers (NLC) is chosen because of its ability to dissolve and solve the problem of low skin permeation. The type and ratio of solid and liquid lipids used in NLC affect the physicochemical characteristics, thus affecting the release profile and system stability. Objective: This study aimed to determine the effect of various ratios of Compritol 888 ATO as solid lipid and Miglyol 812 as liquid lipid on the physicochemical stability and Coenzyme Q10 release profile of NLC system. Methods: NLC was prepared using High Shear Homogenization method with three different lipid ratios. The ratio of Compritol 888 ATO : Miglyol 812 was 70:30, 80:20, and 90:10, respectively. NLC was evaluated for drug release and stability parameters including organoleptic, particle size, polydispersity index (PI), pH, viscosity, assay, and entrapment efficiency. Results: The stability test result for 90 days showed increments in the particle size and viscosity, whereas for assay and entrapment efficiency were decreased. The release test results showed no significant difference in the release parameters of the three tested formulas. Conclusion: During stability evaluation, NLC-CoQ10 systems did not significantly change pH and PI values, but statistically significantly changed particle size, viscosity, assay, and entrapment efficiency. The different in lipid ratios used in the formulas did not show significantly different results for release parameters.

Development of Drying Energy Saving Technology of Paperboard by Applying Precipitated Calcium Carbonate Made from Oyster-Shell Byproducts

In this study, we aimed to identify the possibility of the internal application of a precipitated calcium carbonate made from oyster shell byproducts (O-shell PCC) for reducing the drying energy in paperboard mills. The micro-fibrillated cellulose (MFC) was also applied to improve the strength of the paperboard containing O-shell PCC. The O-shell PCC was classified through an 80 mesh screen and then its SEM image, particle size, and zeta potential were analyzed. After the MFC was prepared by micro-grinding hardwood bleached kraft pulp (Hw-BKP), its particle size, viscosity, and fiber width were also measured. The O-shell PCC and MFC were added to the Korean old corrugated container (KOCC) stock to prepare handsheets, and their physical properties and drying energy reduction were measured to determine the effect of the O-shell PCC and MFC on the drying energy saving. The O-shell PCC was effective to improve the bulk and drying energy reduction of handsheets, but the strengths decreased. The MFC was effective in improving the strength, but more drying energy was required as the addition of MFC increased due to its hydrophilic property. In addition, the application of the PCC and MFC, which had not been used in paperboard mills, could increase the production cost. However, the reduced cost of drying energy was estimated to be more than the increased cost of PCC and MFC at the optimum dosage (6% O-shell PCC and 0.2% MFC on o.d. fiber). Therefore, it was concluded that the combination of O-shell PCC and MFC could be effective in saving drying energy in paperboard mills.

Modeling ash deposition and shedding during oxy-combustion of coal/rice husk blends at 70% inlet O2

Co-firing rice husk (RH) and coal with carbon capture using oxy-combustion presents a net carbon negative energy production opportunity. In addition, the high fusion temperature of the non-sticky, silica rich, RH can mitigate ash deposition as well as promote shedding of deposits. To identify the optimum operating conditions, fuel particle sizes, and blend ratios that minimize ash deposition, a Computational Fluid Dynamic methodology with add-on ash deposition and shedding models were employed to predict outer ash deposition and shedding rates during co-combustion of coal/RH in AIR and O2/CO2 (70/30 vol%, OXY70) oxidizer compositions. After ensuring that the fly-ash particle size distributions and particle Stokes numbers near the deposition surface were accurately represented (to model impaction), appropriate models for coal ash and RH ash viscosities that were accurate in the temperature region (1200–1300 K) of interest in this study were identified. A particle viscosity and kinetic energy (PKE) based capture criterion was enforced to model the ash capture. An erosion/shedding criterion that takes the deposit melt fraction and the energy consumed during particle impact into account was also implemented. Deposition rate predictions as well as the deposition rate enhancement (OXY70/AIR) were in good agreement with measured values. While the OXY70 scenario was associated with a significant reduction (60%–70%) in flue gas velocities, it also resulted in larger fly-ash particles. As a result, the PKE distributions of the erosive RH ash were similar in both scenarios and resulted in similar shedding rates.

Insect Infestation Increases Viscosity of Biogenic Secondary Organic Aerosol.

Plant stress alters emissions of volatile organic compounds. However, little is known about how this could influence climate-relevant properties of secondary organic aerosol (SOA), particularly from complex mixtures such as real plant emissions. In this study, the chemical composition and viscosity were examined for SOA generated from real healthy and aphid-stressed Canary Island pine (Pinus canariensis) trees, which are commonly used for landscaping in Southern California. Healthy Canary Island pine (HCIP) and stressed Canary Island pine (SCIP) aerosols were generated in a 5 m3 environmental chamber at 35-84% relative humidity and room temperature via OH-initiated oxidation. Viscosities of the collected particles were measured using an offline poke-flow method, after conditioning the particles in a humidified air flow. SCIP particles were consistently more viscous than HCIP particles. The largest differences in particle viscosity were observed in particles conditioned at 50% relative humidity where the viscosity of SCIP particles was an order of magnitude larger than that of HCIP particles. The increased viscosity for the aphid-stressed pine tree SOA was attributed to the increased fraction of sesquiterpenes in the emission profile. The real pine SOA particles, both healthy and aphid-stressed, were more viscous than α-pinene SOA particles, demonstrating the limitation of using a single monoterpene as a model compound to predict the physicochemical properties of real biogenic SOA. However, synthetic mixtures composed of only a few major compounds present in emissions (<10 compounds) can reproduce the viscosities of SOA observed from the more complex real plant emissions.

Numerical study of ice slurry flow and heat transfer in successive U-bends as part of tubular heat exchangers

Using ice slurry can assist the energy saving in cooling systems. Ice slurries are used as secondary refrigerant in large cooling systems. They are mixtures of tiny ice particles in water and an antifreezing agent. The cooling can be stored in ice particles during off-peak conditions and released during peak condition. The stored cooling in ice slurry must be delivered to the desired system through a heat exchanger. Successive U-bend pipes commonly exist in tubular heat exchangers. However, this configuration has not been investigated yet for ice slurries. The present study aims to investigate the heat transfer of these mixtures in successive in-plane U-bends as part of heat exchangers. Mass transfer between ice slurry and fluid is the main important part of this problem which is considered in the present study. For the simulation of ice slurry, the Eulerian two-fluid numerical method is used along with the consideration of mass transfer between two phases and the kinetic theory of granular flow for ice particles viscosity. Nusselt number and pressure drops are mainly studied for different geometric configurations. The length between two bends are changed from 50 to 400 mm and the radius of curvatures of the bends are changed from 50 to 100 mm. The results of the study indicated that the average Nusselt number increases with the radius of curvature and distance between two U-bend pipes. Two successive U-bends neutralize each other's centrifigual effects, then ice particles have chances to rearrange and reduce the wall temperature in each bend. This effect is more prominent in higher distances between two bends and higher radii of curvature. At low radius of curvatures, the variation of distance between two bends has stronger effect on heat transfer of the system; in such a way that by doubling the distance between two bends, the Nusselt number increases 4.1% and 1.5% respectively for radius of curvatures 50 mm and 100 mm. Also it was shown that by increasing the radius of curvature and distance between two U-bend pipes the skin friction coefficient increases. It can be seen that by increasing the ratio of the distance between two bends to the radius, the performance evaluation criterion (PEC) increases.

PAXTA TOZALASH KORXONALARIDA HAVO OQIMINI CHANGDAN TOZALOVCHI AGREGAT KONSTRUKTSIYASINI TAKOMILLASHTIRISH

A detailed analysis of cyclones for cleaning dusty air coming out of ginneries has been provided in this article. The composition, temperature and speed of the dusty airflow coming out of ginneries have been studied. Depending on the composition of the dusty air, a new unit has been developed with a number of improvements up to the cyclone separator. With the help of the SOLIDWORKS Flow Simulation program, a new model for the design of a unit for cleaning a dusty air flow in a cyclone was developed, and a unit with the highest cleaning efficiency was selected among the new developed models. The design of an improved new cyclone separator unit has been simulated using SOLIDWORKS Flow Simulation software and the results were obtained. The design values of speeds in the SOLIDWORKS Flow Simulation model were theoretically calculated using the Navier-Stokes equations. The pressure, temperature, speed, on their basis, the dynamic viscosity of dust particles inside the unit have been studied, and the results have been obtained.

Ultrasound improves the physicochemical and foam properties of whey protein microgel.

Whey protein microgel (WPM) is an emerging multifunctional protein particle and methods to improve its functional properties are continuously being explored. We developed a method to prepare WPM by heat-induced self-assembly under different ultrasound power (160, 320, 480, and 640 W/cm2) and characterized the particle size, surface hydrophobicity, disulfide bond, viscosity, and foam properties of WPM. Ultrasound increased the particle size of WPM-160 W to 31 μm. However, the increase in ultrasound power gradually reduced the average particle size of samples. The intrinsic fluorescence spectrum showed that ultrasound unfolded the structure of whey protein and exposed more hydrophobic groups, which increased the surface hydrophobicity of WPM. In addition, infrared spectroscopy suggested ultrasound decreased the α-helix content of WPM, implying an increase in the flexibility of protein molecules. The disulfide bond of WPM was broken by ultrasound, and the content of the-SH group increased correspondingly. The rheology indicated that the apparent viscosity decreased with the increase of ultrasonic power. Compared with the control, the ultrasonicated WPM displayed higher foam ability. Ultrasound improved the foam stability of WPM-160 W but destroyed the foam stability of other samples. These results suggest that proper ultrasound treatment can improve the physicochemical and foam properties of WPM.