Viscosity Range Research Articles

Effect of SiO2/CaO on the viscosity and structure of yellow phosphorus slag in the electric furnace

Slag within suitable viscosity range is important for well controlled slag tapping of phosphorus reduction process in electrical furnace. The suitable slag viscosity depends on the adjustment of SiO2/CaO by adding silica. However, the influence of SiO2/CaO on slag viscosity and structure at slag tapping condition is still unknown. In this work, it is found that the slag viscosity increased slightly with increasing SiO2/CaO above the liquidus temperature. This is because the reduction of free oxygen ions (O2–) leads to an increase of the polymerization degree. However, the slag viscosity decreased as the SiO2/CaO ratio increased below the liquidus temperature. The weakening of the crystallization tendency, the formation of eutectic mixtures, and the reduction of Si-O-Ca-O units with larger ionic radii improve the fluidity of the slag. In addition, the presence of phosphorus slightly promoted the polymerization of the silicate network with increasing SiO2/CaO. This is caused by the increasing proportion of modified cations released by phosphorus from the silicate network. Meanwhile, the increasing SiO2/CaO decreased the polymerization degree of the aluminate structure due to the transition of [AlO4] to [AlO5]. The optimal slag discharge temperature range for the slag with a composition of 85 wt% (SiO2 + CaO) and a SiO2/CaO ratio of 0.9 was 1252 °C-1285 °C.

A novel approach for the resource utilization of zinc-bearing dust and sludge via the blast furnace main trough

Minimizing the environmental impact of zinc-bearing dust and sludge (ZDS) while efficiently extracting valuable metals from its intricate mix has become a pressing issue for steel mills. To facilitate comprehensive ZDS usage, we propose a novel approach for recycling ZDS in the blast furnace main trough. This work explores the self-reduction reaction principles of carbon-containing pellets derived from ZDS. Moreover, it examines the consequent alterations in the physical and chemical properties of molten iron and slag. The molten iron temperature inversely correlates with the number of added pellets; the temperature declines as more pellets are introduced. To restrict the molten iron's temperature decrease to within 30℃, it is advisable to limit the quantity of pellets added to 20 kg per ton of molten iron. At 1500℃, the self-reduction reaction of the pellet initiates 1.5 min post its introduction into the molten iron and concludes 12 min thereafter. The pellet mass percentage entering the molten iron is 32 %, whereas the mass percentage of iron elements within the pellet entering molten iron is 64 %. The pellet addition results in an uptick in blast furnace slag viscosity, yet it remains within an acceptable viscosity range (<1Pa·s).

Customizing ultraviolet curable polymer‐ink properties via reactive diluent modification and viscosity control

AbstractIn inkjet 3D printing, material selection plays a crucial role in shaping both printing performance and material characteristics. Achieving the desired properties relies on precisely formulated compositions. In this context, ultraviolet (UV) curable polymers require specific viscosities, typically ranging from 3700 to 5700 mPa·s, to function effectively in 3D printing's material jetting technique, preventing complications during material dispensing. This study formulates UV‐curable polymers by blending four distinct monomers: Genomer 4247 Aliphatic Urethane Dimethacrylate, 1,10‐Decanediol Dimethacrylate, Isobornyl Acrylate, and Methyl Acrylate, within a controlled dark room environment at room temperature to prevent undesired crosslinking reactions during mixing. The selection of these monomers and their compositions is meticulous, considering their capacity to achieve specified viscosities and enhance overall material performance. This formulation process yields a wide range of UV‐curable polymer viscosities. The study employs comprehensive methodologies, including rheometry, Fourier transform infrared analysis, Soxhlet extraction, thermal analysis, and tensile testing, for rigorous evaluation of viscosity, curing efficiency, thermal characteristics, and mechanical performance. Notably, mechanical and chemical performance exhibits marginal differences within the viscosity range, attributed to UV‐curable polymer crosslinking, consistently exceeding 99% for all samples. However, the polymer composed of 98% v/v oligomer and methyl acrylate (MA) demonstrates notably better thermal and mechanical properties due to its 99.91% gel content crosslinking. Remarkable polymer fabrication thus occurs within the desired viscosity range.

Lube Oil Performance Enhancement Using Nano-Polymers Additives during Copolymerization Reaction

Under the parameters of normal engine operation, lubricating oil typically experience periodic shifts in its viscosity. Because of this, engine oils often include polymeric additives that are referred to as viscosity modifiers. The oil is able to give acceptable fluid lubrication at extreme temps due to these additives, which are oil-soluble polymers. The aim of present work to use polymers in form of nano-composites such as Styrene, Octadecyl-methacrylate (ODMC) and Dodecyle-methcrylate (DDMC) for lube oil viscosity index and pour point enhancement during copolymerization reaction. The benzoyl peroxide was used as an initiator. Solubilizes were made using SN-150 mineral base oil from the Al-Dorha refineries in Baghdad, which had a viscosity index of 128, and a viscosity range of 0 to 100°C. Styrene and methacrylate monomer combinations were copolymerized in an SN-150 mineral base oil solution in a nitrogen atmosphere at 60-80°C. A 200 mm3 oil glass reactor fitted with a magnetic stirrer and a reflux condenser was used to conduct the reactions. Five percent by weight of the total monomer was the concentration used. With respect to the monomers, the initiator concentration was 1.0% wt. Seven hours are needed for the whole reaction cycle. The copolymer composition was modified from 5 to 25% wt.% styrene by changing the monomer combination ratio. The advanced statistical analysis is performed to find the optimum conditions by mean of surface response and multiple regression using MINITAB. The optimization finding is obtained at Styrene of 5%, DDMC of 18% and ODMC of 18%, which promotes viscosity index of 197 leading to 51% enhancement in Al-Dora lube oil.

Research on Hydrodynamic Characteristics of Electronic Paper Pixels Based on Electrowetting.

In this paper, we propose a driving waveform with a complex ramp pulse for an electrowetting display system. The relationship between the contact angle and viscosity of inks was calculated based on the fluid-motion characteristics of different viscosities. We obtained the suitable range of viscosity and voltage in the liquid-oil-solid three-phase contact display system. We carried out model simulation and driving waveform design. The result shows that the driving waveform improves the response speed and aperture ratio of electrowetting. The aperture ratio of electrowetting pixels is increased to 68.69%. This research is of great significance to optimizing the structure of fluid material and the design of driving waveforms in electrowetting displays.

A new portable field rotational viscometer for high-temperature melts.

Mounted on top of furnaces, laboratory viscometers can be used for the rheological characterization of high temperature melts, such as molten rocks (lava). However, there are no instruments capable of measuring the viscosity of large volumes of high temperature melts outside the laboratory at, for example, active lava flows on volcanoes or at industrial sites. In this article, we describe a new instrument designed to be easy to operate, highly mobile, and capable of measuring the viscosity of high temperature liquids and suspensions (<1350 °C). The device consists of a torque sensor mounted in line with a stainless-steel shear vane that is immersed in the melt and driven by a motor that rotates the shear vane. In addition, a thermocouple placed between the blades of the shear vane measures the temperature of the melt at the measurement location. An onboard microcomputer records torque, rotation rate, and temperature simultaneously and in real time, thus enabling the characterization of the rheological flow curve of the material as a function of temperature and strain rate. The instrument is calibrated using viscosity standards at low temperatures (20-60 °C) and over a wide range of stress (30-3870Pa), strain rate (0.1-27.9s-1), and viscosity (10-650Pas). High temperature tests were performed in large scale experiments within ∼25 l of lava at temperatures between 1000 and 1350 °C to validate the system's performance for future use in natural lava flows. This portable field viscometer was primarily designed to measure the viscosity of geological melts at their relevant temperatures and in their natural state on the flanks of volcanoes, but it could also be used for industrial purposes and beyond.

Chemorheology of a Si/Al > 3 Alkali Activated Metakaolin Paste through Parallel Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA).

Although geopolymers, as structural materials, should have superior engineering properties than traditional cementitious materials, they often need to improve their final characteristics' reproducibility due to the need for more control of the complex silico-aluminate decomposition and polymerisation stages. Thermosetting of a reactive geopolymeric paste involves tetrahedral Silicate and Aluminate precursor condensation into polyfunctional oligomers of progressively higher molecular weight, transforming the initial liquid into a gel and a structural solid. Viscosity and gelation control become particularly critical when the geopolymer is processed with 3D printing additive technology. Its physical state modification kinetics should match the flow and setting characteristics required by the deposition process. The reaction kinetics and the elastic and viscous characteristics preceding gelation and hardening have been investigated for an alkali-activated Metakaolin/Sodium Silicate-Sodium Hydroxide paste with a Si/Al ratio > 3. A chemoreological approach has been extended to these inorganic polymerisable systems, as already utilised for organic thermosetting polymers. Differential scanning calorimetry and Oscillatory DMA were carried out to monitor the advancement of the polymerisation reaction and the associated variations of the rheological viscoelastic properties. Dynamic thermal scans were run at 1 °C/min and a frequency of 10 Hz for the dynamic mechanical tests. The observed kinetics of polymerisation and variations of the elastic and viscous components of the complex viscosities and shear moduli are described in terms of polycondensation of linear and branched chains of oligomeric macromolecules of increasing complexity and molecular weight up to gelation (Gel1) and cross-linking of the gelled macrostructure (Gel2) and final glassy state. Geopolymerization can be allocated into two main behavioural zones: a viscoelastic liquid paste below 32.5% of reaction advancement and a viscoelastic solid above. Initial complex viscosities range from 2.3 ± 0.9 × 10-5 MPa*s to 6.8 ± 0.9 × 10-2 in the liquid-like state and from 1.9 ± 0.1 MPa to 9.6 ± 2.1 × 102 MPa in the solid-like state.

Quantifying the Viscosity of Individual Submicrometer Semisolid Particles Using Atomic Force Microscopy.

Atmospheric aerosols' viscosities can vary significantly depending on their composition, mixing states, relative humidity (RH) and temperature. The diffusion time scale of atmospheric gases into an aerosol is largely governed by its viscosity, which in turn influences heterogeneous chemistry and climate-relevant aerosol effects. Quantifying the viscosity of aerosols in the semisolid phase state is particularly important as they are prevalent in the atmosphere and have a wide range of viscosities. Currently, direct viscosity measurements of submicrometer individual atmospheric aerosols are limited, largely due to the inherent size limitations of existing experimental techniques. Herein, we present a method that utilizes atomic force microscopy (AFM) to directly quantify the viscosity of substrate-deposited individual submicrometer semisolid aerosol particles as a function of RH. The method is based on AFM force spectroscopy measurements coupled with the Kelvin-Voigt viscoelastic model. Using glucose, sucrose, and raffinose as model systems, we demonstrate the accuracy of the AFM method within the viscosity range of ∼104-107 Pa s. The method is applicable to individual particles with sizes ranging from tens of nanometers to several micrometers. Furthermore, the method does not require prior knowledge on the composition of studied particles. We anticipate future measurements utilizing the AFM method on atmospheric aerosols at various RH to aid in our understanding of the range of aerosols' viscosities, the extent of particle-to-particle viscosity variability, and how these contribute to the particle diversity observable in the atmosphere.

Signal analysis to study the impact of tongue roughness on oral friction mechanisms with a custom-built tribometer

A custom-built tribometer was employed to investigate the impact of the roughness of deformable tongue mimicking surfaces (TMS) on friction mechanisms occurring under the effect of lubrication with Newtonian solutions of glycerol. TMSs with modulated roughness (range of asperity heights Ra: 20–140 μm) were manufactured from gels of polyvinyl alcohol (PVA). Newtonian aqueous solutions of glycerol covering a wide range of viscosity (1–1400 mPa.s) were used as simple food models spread on the TMSs. The tribological behavior of the system was studied during shear back and forth movements. The ratio between tangential and normal forces was analyzed both in terms of average values and of fluctuations, over specific time periods set at the end of motion and rest steps. The average values of friction level were reported to increase when (i) the roughness of the TMSs increased and when (ii) the viscosity of glycerol solutions decreased. These trends could be consistent with mixed lubrication. The fluctuations of friction level during motion steps were for their part generally of higher amplitude as the roughness of the surface increased, with main frequencies ranging from 10 to 20 Hz. The study demonstrates the importance (i) of the biological relevance of tongue properties (contact areas, rigidity, and asperity heights) and (ii) of the thorough analysis of tangential to normal force ratio to better understand the complex mechanisms of friction occurring in the mouth during food consumption.

Thermal Reflow Simulation for PMMA Structures with Nonuniform Viscosity Profile.

This paper presents a new approach to the simulation of the thermal reflow of e-beam-exposed polymethyl methacrylate (PMMA) taking into account its nonuniform viscosity profile. This approach is based on numerical "soapfilm" modeling of the surface evolution, processed by the free software "Surface Evolver" in area normalization mode. The PMMA viscosity profile is calculated via the simulation of the exposed PMMA number average molecular weight distribution using the Monte-Carlo method and empirical formulas. The relation between the PMMA viscosity and the mobility of PMMA surface vertices was determined via the thermal reflow simulation for uniform PMMA gratings using analytical and numerical approaches in a wide viscosity range. The agreement between reflowed profiles simulated with these two approaches emphasizes the applicability of "soapfilm" modeling in the simulation of polymer thermal reflow. The inverse mobility of PMMA surface vertices appeared to be proportional to the PMMA viscosity with a high precision. The developed approach enables thermal reflow simulations for complex nonuniform structures, which allows the use of predictable reflow as a stage of 3D microfabrication.

A novel near-infrared fluorescent probe for ultrasensitive and visual detection of mitochondrial viscosity

The development of fluorescent probes capable of detecting abnormal changes in cellular mitochondrial viscosity is of great significance, as these changes have been connected to many diseases. In this study, the conventional tetraphenylethylene (TPE) molecule was modified to fabricate a novel near-infrared fluorescent, TTPB, which was then used to measure the mitochondrial viscosity. Due to the introduction of TPE and pyridine groups, TTPB had an AIE effect and mitochondrial targeting function. Meanwhile, TTPB was extremely sensitive to variations in viscosity for the twisted intramolecular charge transfer (TICT) phenomenon. The logarithm of fluorescence intensity (logI620) of the probe demonstrated an excellent linear connection with the logarithm of viscosity (logη) in the viscosity range of 1.2 ∼ 956.0 cP, indicating the probe could quantitatively detect viscosity. Moreover, TTPB was able to visually track autophagy in addition to detecting the mitochondrial viscosity in the inflammatory cell model. These results showed that the probe was anticipated to be employed for the early diagnosis of related diseases.

Viscosity determination of the biomass slag in the SiO2-CaO-K2O system based on the bond distribution

The slag mobility is a key factor influencing the slag tapping process during the slagging gasification of biomass. However, the viscosity model suitable for the biomass slag (relevant to the SiO2-CaO-K2O system) has not been reported yet. This study firstly proposed an Arrhenius-type viscosity model based on the bond distribution in biomass slag. The bond information of the biomass slag was determined by61 thermodynamic modelling. The quantified relation between the slag composition (SiO2, CaO, and K2O) and bond distribution (Si-Si-O-O, Si-Ca-O-O, and Si-K-O-O), and the relation between the bond distribution and activation energy of viscous flow (Ea) or pre-exponential factor (A) were established, respectively. The standard deviations of our model are 1.71 Pa·s in the 0–100 Pa·s and 0.61 Pa·s in the 2.5–25 Pa·s, respectively. The newly built viscosity model shows superior prediction performance than the empirically viscosity models, and owns better performance than the FactSage model in the optimal viscosity range (2.5–25 Pa·s) of the smooth slag tapping process.

Assessment of the relationship between lubricating oil viscosity and surface-attached adhesion rate via regression modelling

This study used a regression model, experimental data from a viscosity measurement device, and a computational technique to investigate the relationship between lubricant viscosity and surface-attached adhesion rates. Three types of used lubricants were identified and evaluated using viscosity and surface adhesion measuring instruments using three different sizes of steel balls, namely 3 mm, 3.5 mm, and 4 mm. The experimental results were then analysed using a simple linear regression model with parameter estimation. At a significance level of 0.05, the results revealed that the lubricant viscosity and the rate of surface adhesion were linearly correlated. The results of this research could be utilized by industry to control the usage of lubricating oil in industrial parts, make judgments about changing or analysing the quality of the heat-reducing lubricant at the interface between mechanical components, and so on. To maintain lubrication efficiency and increase the service life of industrial parts. As a result of fulfilling this desired goal, the regression equations generated during this study can be used to estimate surface-attached adhesion rates in other circumstances. The viscosity range utilised in this case study corresponds to the normal viscosity of the unused lubricant. The surface-attached adhesion rate can thus be accurately selected by manufacturers, and the lubrication effectiveness can also be monitored. This is another indirect waste reduction in the manufacturing chain.

Analysis of magma rheology from lava spreading and explosive activity during the 2020–21 eruption of La Soufrière, St Vincent, with implications for eruption dynamics

Abstract We apply dynamical models to estimate the rheological properties of magma and lava during the 2021–22 eruption of La Soufrière Volcano, St Vincent. Analysis of the emplacement of a lava coulée gives viscosities in the range 0.94 × 10 10 Pa s to 5.97 × 10 10 Pa s. A static Bingham model gives a yield strength of 4.1 × 10 5 Pa. A dynamical model of conduit flow during the explosive phase of the eruption gives a viscosity range from 1.2 × 10 7 to 2.3 × 10 9 Pa s. A petrological model of magma viscosity in the source region falls in the range 10 2 to 10 3 Pa s. The very high viscosity of the lava is attributed to the presence of a remnant degassed and partially crystallized magma from previous eruptions that occupied the shallow conduit–vent system prior to onset of the 2021 explosive eruptions. Gas-rich magma pushed this degassed remnant magma out over a three-month period at a steady rate of about 1.2 m 3 s −1 and the explosive phase began when volatile-rich and much lower viscosity magma reached the surface.

Development of a vertical bubble acoustic microfluidic sputum liquefier for improved cancer cell detection

The detection of cancer in the lower respiratory tract is often performed using sputum smears, which is a convenient method. However, due to its high viscosity, it can be difficult to concentrate target cancer cells from sputum. To improve sputum smear and cancer cell detection, it is highly desirable to have efficient sputum liquefaction approaches. Our study focused on the development of a vertical bubble acoustic microfluidic sputum liquefier that can mix sputum and lysis buffer in a harmless and efficient manner. The system can automatically process sputum samples with a wide range of viscosities without vortexing. Moreover, well-liquefied sputum samples can easily concentrate cancer cells, leading to improved efficiency and accuracy of diagnosis compared to the direct smear method. We expect that our device will increase the positive rate of pathological examination of sputum smears in patients with lung cancer in the future.

Experimental study on energy harvesting maximization from the flow-induced vibration of a highly confined bluff body

Flow-induced vibrations of rigid prisms supported elastically were studied experimentally in a free-surface water channel with a high blockage (2/5). The study focused on finding the prism cross-sectional shape that maximizes the efficiency of energy harvesting. Seven cross-sectional shapes were tested: square, circular, 45° tilted square, equilateral triangle, isosceles 120° triangle, D-section, and C-section. All other dimensionless parameters of the problem, mass ratio, damping, blockage ratio, reduced velocity range, and the Reynolds (Re) number (characteristic velocity times characteristic length divided by kinematic viscosity) range (400–1070), were kept unchanged. By doing so, the effect of the cross-sectional shape was isolated. D-section proved to be the geometry with the highest values of energy transfer efficiency. A hysteresis loop was present in its oscillatory response (dimensionless oscillation amplitude vs reduced velocity). This loop was characterized by two branches, (+) and (−), meaning a bi-valued amplitude response for each reduced velocity. Regarding temporal patterns of wake topology and body motion, it was found that synchronization occurs in the (+) branch, but not in the (−). Regarding vortex shedding modes, particle image velocimetry was used for identification purposes, and it was found that the 2P mode is the dominant mode in the (+) branch, while the 2S mode pervades the (−). Finally, a new relative reduced velocity definition was introduced, and, when re-plotting the experimental results, it was found that the hysteresis loop disappears, thereby providing a more compact mathematical description of the observed phenomena.

A bio-inspired slippery coating with mechanochemical robustness for anti-ice and anti-corrosion

Slippery coatings with outstanding liquid repellency and drag reduction are essential for energy saving and economic society. However, their long-term durability is still limited by weak slippery capacity and mechanochemical stability. Here, a manta ray skin inspired coating (MSC) via straightforward spraying method is developed. The rational design of the hemispherical structures composed of silicon-containing materials endows a transparent and robust slippery surface with hardness of 0.94 GPa and an extremely low friction coefficient of 0.076. The MSC can be applied on diverse substrates with strong adhesion and exhibits an outstanding resistance to liquid with a wide range of surface tension and viscosity up to 1,499 mPa·s. The coating maintains transparency and sustains liquid repellency after 1,000 abrasion cycles under 250 g loads or 32 days treatment at extreme high/low temperatures. In addition, the distinct anti-icing/de-icing properties and good anti-corrosion performance along with a facile spraying process provide MSC a tremendous potential for achieving industrial applications.

Development of an oscillating cup viscometer for viscosity measurement of liquid metals at very high temperatures

The dynamic viscosity of molten metals is measured over a wide temperature range up to 2100 K using an oscillating cup viscometer. In order to further reduce the measurement uncertainties, a particular attention is paid to thermal effects, temperature measurement, acquisition and analysis of the mechanical response of the oscillating pendulum. Experiments are first conducted at low temperature with standard liquids, covering a wide range of viscosities from 1 mPa.s to 500 mPa.s. These preliminary tests helped to assess the accuracy and reliability of the Shvidkovskiy approach used to calculate viscosity. Further experiments were then performed at very high temperature using an induction furnace. As a result, the dynamic viscosity has been successfully measured over the temperature range 506–2135 K for liquid tin, and 710–1770 K for liquid lead, providing unpublished data. Additionally, this was achieved while maintaining a relatively low uncertainty of about 2.5% despite the very high temperature reached here.

Characterisation of a Coriolis flow meter for fuel consumption measurements in realistic drive cycle tests

When testing light-duty and heavy-duty vehicles on chassis dynamometers, as in the WLTP, or engines on engine test benches, as in the WHDC, it is required to measure the fuel consumption. In the preferable case, the measurement of the fuel consumption is carried out with suitable flow meters. These require high measurement accuracy in a wide flow range, independent of the fuel type, as the flow rate range is often very large and depends on the power range of the vehicle engines. Moreover, the fuel flow rate in the test cycles is very dynamically related to the loads. In the scope of the ongoing EMPIR Joint Research Project 20IND13 SAFEST the dynamic flow behaviour as well as the measurement accuracy of flow meters for different types of fuels are investigated. This paper presents first results from the realisation of dynamic flow profiles, and flow measurements with a Coriolis Flow Meter with different representative fuels in a wide density and viscosity range and a wide flow rate range at different fuel temperatures.

Design and evaluation of adapalene microemulsion for transfollicular drug delivery through guinea pig skin.

Acne vulgaris can be treated topically with adapalene, a synthetic derivative of naphthoic acid with retinoid activity. Adapalene has a very low rate of percutaneous absorption and is almost completely insoluble in water. To obviate this problem, microemulsion (ME) carrier is used. The study's goals were to create and characterize adapalene-loaded ME and assess the drug's transfollicular route of penetration to see if hair follicles can serve as a conduit for the drug to enter the skin. Adapalene microemulsions (MEs) are made by combining the right amounts of the cosurfactant (propylene glycol), surfactant (Tween 80 and Span 20), and oil phase (oleic acid-Transcutol P (10:1)). Physical and chemical characteristics of MEs, including droplet size, stability, viscosity, drug release, and in vitro skin permeability via guinea pigs' hairy and non-hairy skin, were assessed. The range of 13.86-56.16 nm was found to be the average droplet size of ME formulations. The range of viscosities was 117-240 cps. The drug release profile reveals that 95.374 percent of the drug was released within the experiment's first 24 h. Compared to the adapalene control (aqueous suspension), all MEs enhanced the adapalene flow through both hairy and non-hairy skin. The surfactant/cosurfactant ratio had an impact on the amount of drug that passed through both skins because a larger ratio enhanced the adapalene affinity in the follicular route. Furthermore, the proportions of the water and oil phases in formulations, as well as the S/C ratio, have a significant impact on the physicochemical characteristics and adapalene permeability across both pathways.