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In this study, an electrode slurry composed of molybdenum disulfide (MoS2) and vapor-grown carbon fiber (VGCF) prepared through a solid-phase synthesis method was blade-coated onto copper foil to form a thick film as the anode for lithium-ion batteries. In previously reported work, MoS2-based lithium-ion batteries have experienced gradual deformation, fracture, and pulverization of electrode materials during the charge and discharge cycling process. This leads to an unstable electrode structure and rapid decline in battery capacity. Furthermore, MoS2 nanosheets tend to aggregate over charge and discharge cycles, which diminishes the surface activity of the material and results in poor electrochemical performance. In this study, we altered the density of the MoS2–carbon fiber/Cu foil anode electrode by rolling. Three different densities of electrode sheets were obtained through varying rolling repetitions. Our study shows the best electrochemical performance was achieved at a material density of 2.2 g/cm3, maintaining a capacity of 427 mAh/g even after 80 cycles. [ABSTRACT FROM AUTHOR]

Abstract The damping coefficient serves to quantify the energy dissipation in particle collisions and constitutes a crucial parameter in discrete element simulations. Nevertheless, the factors influencing the damping coefficient remain unclear, and the damping coefficients of the majority of materials have not been precisely determined. In this investigation, the damping coefficients of eight representative particles were studied using the acoustic frequency sampling method, and the correlations between these coefficients and collision velocity, material density, and elastic modulus were analyzed. The findings indicate that damping coefficients exhibit insensitivity to velocity in strongly elastic and moderately elastic material particles. Conversely, for weakly elastic material particles, damping coefficients demonstrate an increase with rising velocity. The damping coefficient of metallic particles exhibits a linear relationship with material density and elastic modulus.

Background: Zirconia is a widely used material in the dental industry due to its excellent mechanical and aesthetic properties. Recently, a new 3D printing process called suspension-enclosing projection stereolithography (SEPS) was introduced to fabricate zirconia dental restorations. However, the effect of the sintering time and temperature on the properties of zirconia produced via SEPS has not been fully investigated. Methods: Zirconia slurries were prepared with varying percentages of zirconia powders and 3D printing resins, and 5Y-TZP (5 mol% yttria-stabilized zirconia) (n = 40) and 3Y-TZP (3 mol% yttria-stabilized zirconia) (n = 40) bar specimens were fabricated via SEPS manufacturing. The specimens were sintered at different temperatures and dwell times, and their flexural strength, density, and phase composition were measured. The viscosity of the slurries was also measured. Statistical analysis was performed using Welch's ANOVA and Kruskal–Wallis tests to evaluate the impact of the sintering conditions. Results: Significant differences in flexural strength (p < 0.01) were observed between the 5Y-TZP samples, with those sintered at 1530 °C for 120 min showing an average strength of 268.34 ± 44.66 MPa, compared to 174.16 ± 42.29 MPa for those sintered at 1450 °C for 120 min. In terms of density, significant differences (p < 0.01) were noted for the 3Y-TZP specimens, with an average density of 6.66 ± 0.49 g/cm3 for samples sintered at 1530 °C for 120 min, versus 5.75 ± 0.55 g/cm3 for those sintered at 1530 °C for 10 min. X-ray diffraction confirmed the presence of a predominantly tetragonal phase in both materials. Conclusions: Zirconia printed via SEPS manufacturing can be sintered at a higher temperature with shorter dwell times, thereby producing high density samples. Different sintering conditions can be used to fully sinter 3D-printed zirconia for potential dental applications. [ABSTRACT FROM AUTHOR]

In this study, an electrode slurry composed of molybdenum disulfide (MoS2) and vapor-grown carbon fiber (VGCF) prepared through a solid-phase synthesis method was blade-coated onto copper foil to form a thick film as the anode for lithium-ion batteries. In previously reported work, MoS2-based lithium-ion batteries have experienced gradual deformation, fracture, and pulverization of electrode materials during the charge and discharge cycling process. This leads to an unstable electrode structure and rapid decline in battery capacity. Furthermore, MoS2 nanosheets tend to aggregate over charge and discharge cycles, which diminishes the surface activity of the material and results in poor electrochemical performance. In this study, we altered the density of the MoS2–carbon fiber/Cu foil anode electrode by rolling. Three different densities of electrode sheets were obtained through varying rolling repetitions. Our study shows the best electrochemical performance was achieved at a material density of 2.2 g/cm3, maintaining a capacity of 427 mAh/g even after 80 cycles.

Additive manufacturing (AM) or 3D printing has opened up new opportunities for researchers in the field of electrical machines, as it allows for more flexibility in design and faster prototyping, which can lead to more efficient and cost-effective production. An overview of the primary AM techniques utilized for designing electrical machines is presented in this paper. AM enables the creation of complex and intricate designs that are difficult or impossible to achieve using traditional methods. Topology Optimization (TO) can be used to optimize the design of parts for various purposes such as weight, thermal, material usage and structural performance. This paper primarily concentrates on the most recent studies of the AM and TO of the reluctance machines. The integration of AM with TO can enhance the design and fabrication process of magnetic components in electrical machines by overcoming current manufacturing limitations and enabling the exploration of new design possibilities. The technology of AM and TO both have limitations and challenges which are discussed in this paper. Overall, the paper offers a valuable resource for researchers and practitioners working in the field of AM and TO of electrical machines. [ABSTRACT FROM AUTHOR]

The withdrawal and lateral holding properties of three types of plywood with one stapled as well as one-row multi-stapled joints were studied and compared. The results show that variations in plywood density have a significant effect on withdrawal strength and a relatively small effect on lateral holding strength. At four staples, the withdrawal strength of the eucalyptus plywood with a density of 0.59 g/cm3 is 1821 N, which is 21% higher than that of poplar plywood with a density of 0.51 g/cm3 at 1498 N and 32% higher than that of eucalyptus/poplar composite plywood with a density of 0.53 g/cm3 at 1275 N. In terms of lateral holding strength, eucalyptus plywood has a lateral holding strength of 1603 N 12% lower than the 1807 N of eucalyptus/poplar composite plywood and 10% lower than the 1761 N of poplar plywood. As the number of staples increased from 1 to 4 in increments of 1, the withdrawal strength of eucalyptus plywood continued to increase, while the nodal strengths of the poplar plywood as well as eucalyptus/poplar composite plywood did not differ significantly between 3 and 4 staples, and there is a significant increase in the lateral holding strength for all three plywood nodes. Equations for predicting the withdrawal and lateral holding strengths of one-row multi-stapled joints were derived separately. [ABSTRACT FROM AUTHOR]

Background: This study investigates the correlation and discriminative diagnostic accuracy of dual-energy CT (DECT)-derived imaging biomarkers in patients with acute pancreatitis of varying severity. Methods: In this retrospective study, we included 51 patients with acute pancreatitis who had undergone portal-venous phase DECT of the abdomen. Three blinded readers independently performed region-of-interest measurements on DECT images in the inflammatory pancreatic parenchyma. The correlation between modified CT severity index (CTSI) and quantitative imaging parameters was investigated using Pearson correlation coefficient. We performed receiver operator curve (ROC) analysis to assess diagnostic accuracy of the quantitative image parameters for the differentiation between mild/moderate versus severe acute pancreatitis. The optimal discriminative cut-off value to diagnose severe acute pancreatitis was determined using the Youden index. Results: Moderate correlations were found between CTSI scores and iodine density (Pearson's correlation coefficient r = −0.65; p < 0.001), as well as attenuation (r = −0.55; p < 0.001) and normalized iodine uptake (r = −0.50; p < 0.001). ROC curve analysis revealed highest ability to differentiate mild/moderate from severe acute pancreatitis for iodine density (AUC = 0.86, 95% confidence interval 0.75 to 0.97). An optimal iodine density threshold of ≤1.63 mg/mL was found to indicate severe acute pancreatitis with a sensitivity of 81.3% and specificity of 77.1%. Conclusion: DECT-derived iodine density correlates with acute pancreatitis severity and may facilitate prediction of severe acute pancreatitis. [ABSTRACT FROM AUTHOR]

In this study, the thermal conductivity (k-values) of pure and composite samples obtained from raw materials which these samples came from different parts (stalk, fiber) and different regions (bottom, middle and top) of nettle plants and collected from low and high altitudes (350 and 2100) in the Black Sea regions were investigated depending on orientation and temperature. According to the ASTM C518 standard, the k-value is only given for the temperature value of 10 °C. However, it is also important to determine the thermal conductivity depend on climatic conditions, ambient temperature, and humidity. It is known that the thermal conductivity coefficient changes depend on the density, pore structure and size, humidity, and temperature. However, for materials with a fibrous structure (rock wool, glass wool, VIP), the orientation of the fiber structure depends on the heat transfer direction also significantly affects the thermal conductivity. In the first stage of the study, the pure thermal conductivity of cellulosic materials was determined. The fiber parts of the nettle plant, which have low thermal conductivity (k < 0.040 W/mK), were used in the formation of the composites. In this context, the thermal conductivity of composites formed with fibers obtained from two different altitudes was characterized depend on temperature (0 ºC, 10 ºC, 20 ºC, 30 ºC, 40 ºC) and orientation (0º, 45º, 90º). Ratios such as 2.5 %, 5 %, 7.5 %, and 10 % by volume were used to form the composite, and the effect of orientation and temperature was measured in composites with a 10 % reinforcement ratio. The manual laying method was used in the production of test samples. The physical and chemical properties of the reinforcement material affecting the thermal conductivity of the composites were determined and its effect on the thermal conductivity coefficient was discussed. In the conducted study, it was determined that the altitude difference affects the characteristic features of the plant (such as fiber diameter, crystal structure, and density), and accordingly, the thermal conductivity behaviors show differences. On the other hand, it was determined that orientation significantly affects the thermal conductivity coefficients, but the effect of temperature increase on the thermal conductivity coefficient change in the same composites is low. As a result, it has been concluded that the fibers obtained from the bottom parts of the plants obtained from high altitudes may be a more suitable insulation material than the fibers obtained from the other part. [ABSTRACT FROM AUTHOR]

The geometrical and topological features of metal-organic frameworks (MOFs) play an important role in determining their ability to capture and store methane (CH4). Methane is a greenhouse gas that has been shown to be more dangerous in terms of contributing to global warming than carbon dioxide (CO2), especially in the first 20 years of its release into the atmosphere. Its accelerated emission increases the rate of global temperature increase and needs to be addressed immediately. Adsorption processes have been shown to be effective and efficient in mitigating methane emissions from the atmosphere by providing an enormous surface area for methane storage. Among all the adsorbents, MOFs were shown to be the best adsorbents for methane adsorption due to their higher favorable steric interactions, the presence of binding sites such as open metal sites, and hydrophobic pockets. These features may not necessarily be present in carbonaceous materials and zeolites. Although many studies have suggested that the main reason for the increased storage efficiencies in terms of methane in the MOFs is the high surface area, there was some evidence in certain research works that methane storage performance, as measured by uptakes and deliveries in gravimetric and volumetric units, was higher for certain MOFs with a lower surface area. This prompted us to find out the most significant property of the MOF, whether it be material-based or pore-based, that has the maximum influence on methane uptake and delivery, using a comprehensive statistical approach that has not previously been employed in the methane storage literature. The approach in our study employed various chemometric techniques, including simple and multiple linear regression (SLR and MLR), combined with different types of multicollinearity diagnostics, partial correlations, standardized coefficients, and changes in regression coefficient estimates and their standard errors, applied to both the SLR and MLR models. The main advantages of this statistical approach are that it is quicker, provides a deeper insight into experimental data, and highlights a single, most important, parameter for MOF design and tuning that can predict and maximize the output storage and capture performance. The significance of our approach is that it was modeled purely based on experimental data, which will capture the real system, as opposed to the molecular simulations employed previously in the literature. Our model included data from ~80 MOFs and eight properties related to the material, pore, and thermodynamics (isosteric adsorption energy). Successful attempts to model the methane sorption process have previously been conducted using thermodynamic approaches and by developing adsorption performance indicators, but these are either too complex or time-consuming and their data covers fewer than 10 MOFs and a maximum of three MOF properties. By comparing the statistical metrics between the models, the most important and statistically significant property of the MOF was determined, which will be crucial when designing MOFs for use in storing and delivering methane. [ABSTRACT FROM AUTHOR]

Chemical and grain-size analysis of AlSi10Mg alloy powder has been performed. It has been found that the powder particles are generally nonspherical, with a significant number of inclusions in the form of satellites. The particle size distribution ranges from 5 to 60 μm. The presence of conglomerates up to 70 μm in size is observed. Studies on the effect of scanning parameters on the tensile strength and relative elongation of the samples have been performed. It has been found that, in the range of the scanning velocity from 910 to 930 mm/s, local mechanical minima are observed. In order to optimize the scanning parameters, complex quality parameters are used. The greatest desirability from the standpoint of obtaining the maximum strength and plasticity of the material consists in a combination of the scanning parameters: laser power of 350 W, scanning pitch of 0.19 mm, scanning velocity of 980 mm/s at a layer thickness of 50 μm. The test results of cylindrical samples made at the angles of 0° and 90° with respect to the construction platform are presented. [ABSTRACT FROM AUTHOR]

The withdrawal and lateral holding properties of three types of plywood with one stapled as well as one-row multi-stapled joints were studied and compared. The results show that variations in plywood density have a significant effect on withdrawal strength and a relatively small effect on lateral holding strength. At four staples, the withdrawal strength of the eucalyptus plywood with a density of 0.59 g/cm3 is 1821 N, which is 21% higher than that of poplar plywood with a density of 0.51 g/cm3 at 1498 N and 32% higher than that of eucalyptus/poplar composite plywood with a density of 0.53 g/cm3 at 1275 N. In terms of lateral holding strength, eucalyptus plywood has a lateral holding strength of 1603 N 12% lower than the 1807 N of eucalyptus/poplar composite plywood and 10% lower than the 1761 N of poplar plywood. As the number of staples increased from 1 to 4 in increments of 1, the withdrawal strength of eucalyptus plywood continued to increase, while the nodal strengths of the poplar plywood as well as eucalyptus/poplar composite plywood did not differ significantly between 3 and 4 staples, and there is a significant increase in the lateral holding strength for all three plywood nodes. Equations for predicting the withdrawal and lateral holding strengths of one-row multi-stapled joints were derived separately.

The mechanism of transfer film formation in the friction process of two solids (nanocomposites polyether ether ketone (PEEK)/graphene and counterpart from quenched steel) and the influence of this process on the frictional wear rate of the considered nanocomposites was studied. It was demonstrated earlier that introduction of fillers in polymers leads to an essential change of basic characteristics of transfer film (its thickness and relative area of coverage by transfer film of counterpart surface). In its turn, this change influences strongly on a tribological characteristics of composites. It has been shown in the present paper, that the thickness of the transfer film depends linearly on the value of the ratio of two characteristics of the considered nanocomposites, namely, their shear stability and density of cohesion energy, characterized to a first approximation by elastic modulus of these nanocomposites. The increasing thickness of the transfer film from 0.2 to 2.0 μm leads to a linear growth of the frictional wear rate from ~1 to 9 mm2/(N m). The structural analysis of frictional wear within the frameworks of fractal analysis was demonstrated decreasing both shear stability of nanocomposites and thickness of transfer film during growth of the fractal dimension of structures of these nanomaterials in virtue of enhancement of their density and cohesion energy. As the dimension of the structure approaches that of Euclidean space the frictional wear rate reaches its minimal, but finite, value due to the fact that the dimension of real physical bodies is always smaller then Euclidean ones. [ABSTRACT FROM AUTHOR]

This paper presents a numerical study of the hydroelastic coupling during the free-surface water entry of deformable spheres of different material densities. The focus is on the hydrodynamic forces, the stress loads, the sphere deformations, the wetted areas of the sphere and the cavity dynamics, including the impacting of the elastic spheres and the hydroelastic coupled behaviors in the free surface flows. It is shown that the elastic wave propagation in the sphere scales with the sphere density. For elastic spheres immersed in the water, the variation of the sphere deformations and its energy transformation mechanism are discussed. From the contact point positions of the cavity, it can be seen that the wetted area of the sphere is closely related with the sphere deformation. The first deformation cycle is a turning point in the relation between the wetted area and the sphere density. Based on the map of m* − η summarized in this work, the influence of the sphere deformation on the shape of the cavity can be roughly predicted from the material properties and the impact conditions. [ABSTRACT FROM AUTHOR]

Background: This study investigates the correlation and discriminative diagnostic accuracy of dual-energy CT (DECT)-derived imaging biomarkers in patients with acute pancreatitis of varying severity. Methods: In this retrospective study, we included 51 patients with acute pancreatitis who had undergone portal-venous phase DECT of the abdomen. Three blinded readers independently performed region-of-interest measurements on DECT images in the inflammatory pancreatic parenchyma. The correlation between modified CT severity index (CTSI) and quantitative imaging parameters was investigated using Pearson correlation coefficient. We performed receiver operator curve (ROC) analysis to assess diagnostic accuracy of the quantitative image parameters for the differentiation between mild/moderate versus severe acute pancreatitis. The optimal discriminative cut-off value to diagnose severe acute pancreatitis was determined using the Youden index. Results: Moderate correlations were found between CTSI scores and iodine density (Pearson’s correlation coefficient r = −0.65; p < 0.001), as well as attenuation (r = −0.55; p < 0.001) and normalized iodine uptake (r = −0.50; p < 0.001). ROC curve analysis revealed highest ability to differentiate mild/moderate from severe acute pancreatitis for iodine density (AUC = 0.86, 95% confidence interval 0.75 to 0.97). An optimal iodine density threshold of ≤1.63 mg/mL was found to indicate severe acute pancreatitis with a sensitivity of 81.3% and specificity of 77.1%. Conclusion: DECT-derived iodine density correlates with acute pancreatitis severity and may facilitate prediction of severe acute pancreatitis.

Diurnal and seasonal variations in the apparent density of ambient fine and coarse particulate matter (PM2.5 and CPM [PM2.5-10], respectively) were investigated in a location near downtown Los Angeles. The apparent densities, determined by particle mass-to-volume ratios, showed strong diurnal and seasonal variations, with higher values during the warm phase (June to August 2013) compared to cold phase (November 2012 to February 2013). PM2.5 apparent density showed minima during the morning and afternoon rush hours of the cold phase (1.20g cm(-3)), mainly due to the increased contribution of traffic-emitted soot particles, and highest values were found during the midday in the warm phase (2.38g cm(-3)). The lowest CPM apparent density was observed during the morning rush hours of the cold phase (1.41g cm(-3)), while highest in early afternoon during the warm phase (2.91g cm(-3)), most likely due to the increased wind-induced resuspension of road dust.

Soil moisture content (MC) and density of pavement materials exert a great influence on pavement performance. Cyclic traffic loading with increasing MC in materials can accelerate changes in density significantly. Time domain reflectometry (TDR) is a non-destructive method for measuring MC and density of soil. In this study, TDR measurements were taken in the laboratory for a typical road material at two different conditions; at constant MC with different density and at constant dry density with different MC. Based on TDR measurements, a theoretical formulation between voltage drop occurring for the passage of an electromagnetic wave through the soil and the electrical conductivity (EC) is developed. This relationship is further correlated to develop density function providing the opportunity to obtain MC information. For the validation of the calibration functions, sensors are installed in roads to obtain field data. Laboratory results point out that the calibration models are independent of moisture and density, and the field instrumentation shows the satisfactory accuracy of the method. The newly established calibration models allow for observing the routine performance providing a better understanding of the material behaviour for example rutting of roads. [ABSTRACT FROM AUTHOR]

In this paper, I propose a method to improve the intercomparability of different artifact groups by narrowing the error caused by the differences in material densities. The products, especially of mixed materials, have not been previously analyzed as regards whether or not they have statistically significant differences in material densities or whether the densities affect comparative studies. The results showed that in addition to the obvious material groups like different metals and stones, there is also a significant difference in material densities when comparing redware and clay pipes by their weight. Therefore, the method presented here eliminates the effect of material density, but in a way that it is still intuitive and can be compared with values that have not been density corrected. [ABSTRACT FROM AUTHOR]

The shapes and the sizes of metal oxide particles in polymer-stabilized disperse systems subjected to mechanical activation are considered. The digital processing of images of metal oxide particles is used to determine the parameters of the particles and the adsorbed polymer layers and to find the density change dynamics in an adsorbed layer. [ABSTRACT FROM AUTHOR]

Background: Zirconia is a widely used material in the dental industry due to its excellent mechanical and aesthetic properties. Recently, a new 3D printing process called suspension-enclosing projection stereolithography (SEPS) was introduced to fabricate zirconia dental restorations. However, the effect of the sintering time and temperature on the properties of zirconia produced via SEPS has not been fully investigated., Methods: Zirconia slurries were prepared with varying percentages of zirconia powders and 3D printing resins, and 5Y-TZP (5 mol% yttria-stabilized zirconia) ( n = 40) and 3Y-TZP (3 mol% yttria-stabilized zirconia) ( n = 40) bar specimens were fabricated via SEPS manufacturing. The specimens were sintered at different temperatures and dwell times, and their flexural strength, density, and phase composition were measured. The viscosity of the slurries was also measured. Statistical analysis was performed using Welch's ANOVA and Kruskal-Wallis tests to evaluate the impact of the sintering conditions., Results: Significant differences in flexural strength ( p < 0.01) were observed between the 5Y-TZP samples, with those sintered at 1530 °C for 120 min showing an average strength of 268.34 ± 44.66 MPa, compared to 174.16 ± 42.29 MPa for those sintered at 1450 °C for 120 min. In terms of density, significant differences ( p < 0.01) were noted for the 3Y-TZP specimens, with an average density of 6.66 ± 0.49 g/cm 3 for samples sintered at 1530 °C for 120 min, versus 5.75 ± 0.55 g/cm 3 for those sintered at 1530 °C for 10 min. X-ray diffraction confirmed the presence of a predominantly tetragonal phase in both materials., Conclusions: Zirconia printed via SEPS manufacturing can be sintered at a higher temperature with shorter dwell times, thereby producing high density samples. Different sintering conditions can be used to fully sinter 3D-printed zirconia for potential dental applications.

This paper reviews the application of plastered-bamboo wall (PBW) as an alternative wall construction to replace a conventional brick wall, that are evaluated based on thermal aspects. Brick as the material which is composed of a wall has a high value of density. High-density materials generally have a great heat capacity and contribute to raising the ambient air temperature. On a large scale, they can trigger the occurrence of a heat island phenomenon (UHI). PBW is a technique of wall construction, which are composed of bamboo as a frame and mortar as a frame cover. The thickness of the PBW ranges from 5 to 9 cm. PBW has a lower value of density than a brick wall. This study aims to test the thermal performance of PBW based on its constituent framework, which is divided into two groups of specimens, namely; bamboo woven, and bamboo array. The samples were tested in the field and arranged in such a way as to be exposed to solar radiation. In practice, the heat capacity of specimens was identified through its density. Meanwhile, the thermal performance of samples was identified through time lag (TL) by using thermocouple and globe thermometer. All the results indicate that specimens with bamboo array have better time lag value (longer time) than all specimens with bamboo woven. [ABSTRACT FROM AUTHOR]

• Aerosol properties particle density, effective density & shape factors are studied. • Aerosols of sodium, SrO 2 , CeO 2 , Steel & mixture are characterized. • SMPS-ELPI and QCM-MASTERSIZER combined techniques are used. • Particle and effective densities are lesser than material density. • Spherical shape factor for sodium, SrO 2 & CeO 2 and Chain like for steel. In the event of Core Disruptive Accident (CDA) condition in a sodium cooled fast reactor (SFR), the environmental source term (i.e. quantity of radioactivity released into the environment surrounding to the reactor) is determined by the activity released from the containment building which in-turn depend on the concentration of radioactive aerosols remain suspended in the containment. The aerosol concentration depletes with progress of time inside the containment. Various models were used to predict the time evolution of aerosol concentration inside the containment. It is observed from the literature that there exists significant difference in the model prediction with simulated experimental condition. One of the reasons is the aerosol characteristics used as an input in the models is not accurate. In particular, the sodium aerosol characteristics (generated by the combustion of sodium) get changed both by physical and chemical processes. The other aerosols like fission products, fuel and structural materials form aggregates with sodium aerosols and their morphological properties are also get changed with progress of time. Hence an experimental study is carried out to determine the morphological properties viz. particle diameters, particle density, effective density, shape factors of sodium combustion aerosols, fission product aerosols (Cerium Oxide and Strontium oxide), structural aerosols (D9 steel) and mixed aerosols of sodium and fission products; and reported in this paper. Since sodium aerosols are hygroscopic, experiments are conducted at 3 different humidity conditions. In all the cases, the aerosol density is found to be lesser than the material density, and it changes with time towards the steady state. In case of sodium aerosols for mass concentration of 2 g/m3, the average particle densities and the standard relative uncertainties arrived at 75%, 55% and 30% RH are 1.67 ± 0.41, 1.43 ± 0.36 and 1.2 ± 0.31 respectively. Sodium aerosols are mostly spherical at humidities of 55% and 75% RH, where as they are deviated from spherical at 30% RH. Particle densities of D9 steel, CeO 2 and SrO 2 aerosols are 3.92 ± 0.58, 4.27 ± 0.54 and 3.57 ± 0.48 g/cc respectively. The CeO 2 and SrO 2 aerosols are found to be nearly spherical whereas the structural steel aerosols are found to be chain-like structures. [ABSTRACT FROM AUTHOR]

This paper discusses the study of the shapes and sizes of polymer droplets formed during the phase separation of their solutions with increasing temperature, as well as the parameters of the transitional layers of polymer condensing on the droplet surface formed during this process. For the study, a copolymer of polyethylene oxide and polypropylene oxide was chosen, whose behavior in aqueous solutions and the change in hydrophilic-hydrophobic balance depends on temperature. It has been established that the application of the method of digital image processing allows the introduction of the quantitative criterion - image intensity of a photo. For a more detailed study of the behavior of polymer molecules at the phase boundary, depending on the temperature, the studies of the temperature-dependent behavior of a number of polymers of different composition and structure have been carried out. The use of the digital image processing method for polymer droplets makes it possible to determine the parameters of droplets and their transition layers, to determine the dynamics of nucleation and droplet growth and density changes in the transition layer by the image intensity parameter. The paper has found out that embryos of pluronic are unevenly distributed by volume of solution with the presence of zones with a maximum number of molecules and a zone with a minimum of assembly of molecules. The practical value of the work is in the fact that the results of the study can be used to assess the dynamics of the separation of polymer solutions without involving the time-consuming and expensive instrumental methods of physical and chemical analysis. [ABSTRACT FROM AUTHOR]

Highlights • An empirical prediction model is developed based on acquired extensive CFD data. • It correlates hydrocyclone performance indicators with a range of key variables. • Effects of feed solid density and concentration are focused in the modelling. • The model is validated against plant data and experimental variable trends. • The comparison with other models suggests that this model is more accurate. Abstract The separation performance of hydrocyclone is affected by many variables, the values of which have to be selected carefully for achieving the optimal design and operation of such a separator. This selection can be done by either empirical or numerical model. The empirical model provides convenience for industrial use by simply correlating cyclone performance indicators with variables under specific conditions. The numerical approach is more general and often performs well in explaining the underlying fundamentals of hydrocyclone operations, though it can also predict the unit performance at the cost of much longer computation time. In this work, an empirical prediction model is developed based on the extensive numerical results acquired by Computational Fluid Dynamics (CFD). This model covers a broad range of conditions. In particular, for the first time, it systematically considers the effects of material density and feed solid concentration at different hydrocyclone geometries. The validity of the model is confirmed by the reasonable agreement between the predicted and measured results in terms of cut size, separation sharpness, pressure drop, and water split. The comparison of the model with others in predicting performance indicators and partition numbers against the measurements shows that the new model is more accurate over the ranges of the variables considered. [ABSTRACT FROM AUTHOR]

In order to investigate the impact of density on the classification behavior of particles in the static classifier of Vertical Spindle Mill, the sensitivity of overflow yield to the increase of air amount for narrowly sized pyrite, carborundum, quartz and coal samples were compared in a lab-scale classifier, respectively. Response surface methodology is used to analyze the combined effect of size and density on the classification. Wide size classification was also conducted and results show that both the yield and R90 of overflow increase with the decreasing of density, and the growth of air amount would also lead them to rise. The Whiten’s model was applied to illustrate the influence of density on the sharpness of classification, corrected cut size and fishhook effect. Results show that material with a lower density would have a higher fishhook effect parameter, classification sharpness and corrected cut size. The increase of air amount would result in a more evident fishhook effect for the high density material. Based on the Whiten’s model, a new classification efficiency model with the addition of particle density in various forms was established. This new model could describe the classification efficiency of materials with different density in the identical experiment conditions. [ABSTRACT FROM AUTHOR]

The paper presents results of an analysis of material density distribution in stampings press-moulded in metal dies from raw refractory materials based on alumina-magnesia-carbon aggregate. The stampings, fabricated on LAEIS HPF 1250 pressing machine, are blanks from which refractory precast shapes are manufactured by means of drying and firing. Samples for material density evaluation were cut out from test stampings with the use of diamond-reinforced disc. Density of the material was determined in thirteen layers of stampings denoted with letters A through M.

The paper presents results of assessment of the unit pressure force within the refractory material volume in the course press-moulding of stampings for refractory precast shapes. The force was evaluated with the use of physical simulation of deformation undergone by lead balls placed in the raw refractory mass subjected to pressing in a metal die. To determine the value of unit pressure force applied to the aggregate grains in the course of stamping press-moulding, physical model of deformation of a sphere induced by the uniaxial stress state was used.

To investigate the effect of size and density on the segregation of particles in the static classifier of vertical spindle mill, classification tests of coal were conducted in a lab-scale classifier, and its performance was evaluated by classification efficiency. Results show that yield and fineness of pulverized fuel​ (PF), as well as the classification efficiency of the whole size, would be improved by increasing the air volume. While the comprehensive classification efficiency reaches around 40% and keeps stable. Meanwhile, the separation phenomenon in the classification process was revealed by comparing the ash content between the feed and PF. Results show that ash content of each size fraction decreases after classification and presents growing trend with the decrease of particle size in PF. Separation effect is especially obvious for coarse particles, and its intensity increases as air volume reduces. Furthermore, such a phenomenon is also verified by industrial data, which proves again that minerals with high density would accumulate in the classifier reject. Deviations in bypass fraction, actual cut size, and comprehensive efficiency between regarding coal as homogeneous or heterogeneous were calculated. Thus, to be more accurate, density should be considered in the investigation of the coal particle behavior within classifier. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to evaluate the performance of material-specific iodine (MS-I) images generated by rapid kV-switching single-source dual-energy computed tomography (rsDECT) for distinguishing post-operative changes from local tumor recurrence in patients on follow-up for pancreatic adenocarcinoma after surgical resection.Methods: In this IRB-approved HIPPA-compliant study, retrospective review of 51 patients who underwent surgical resection of pancreatic adenocarcinoma was conducted and were followed up using contrast-enhanced rsDECT (Discovery CT 750HD, GE Healthcare, Milwaukee, WI). Independent qualitative assessment for presence of local tumor recurrence was performed by two radiologists who evaluated 65 keV (single-energy CT-equivalent interpretation) and 65 keV with MS-I (rsDECT interpretation) in separate sessions. Quantitative analysis of Hounsfield unit (HU, on 65 keV) and normalized iodine concentration (NIC on MS-I images; iodine concentration ratio in post-operative tissue to aorta) was measured. Follow-up imaging, temporal change of CEA and CA 19-9 or biopsy served as reference standard for presence and absence of local recurrence. Sensitivity and specificity of readers and quantitative parameters was calculated and receiver operating characteristic curves and Fisher’s exact test were generated. A p value < 0.05 was considered statistically significant.Results: A total of 51 patients (27 females, 24 males) with mean age of 64 years built the final cohort. Local recurrence was absent in 23 (Group A) and present in 28 (Group B) patients. The follow-up imaging was performed within 7 months of rsDECT. For both readers, the addition of MS-I increased the specificity for tissue characterization and improved reader confidence as compared to 65 keV (specificity: 80% and 56%, respectively) images alone. Quantitative analysis revealed a significantly lower NIC (0.28 vs. 0.35; p < 0.05) for non-recurrent tissue. However, HU was not significantly different for non-recurrent and recurrent tissue (0.63 vs. 0.70; p > 0.05).Conclusion: In inherently complex cases of post-operative pancreatic adenocarcinoma, MS-I images from rsDECT can be a useful adjunct to conventional scans in characterizing loco-regional soft tissue. [ABSTRACT FROM AUTHOR]

Purpose: To determine the diagnostic potential of Material Density (MD) iodine images in dual-energy CT (DECT) for the detection and characterization of hypervascular liver lesions compared to monenergetic 65keV images, using MRI as the standard.Materials and Methods: The study complied with HIPAA guidelines and was approved by the institutional review board. Fifty-two patients (36 men, 16 women; age range, 29-87 years) with 236 hypervascular liver lesions (benign, n=31; malignant, n=205; mean diameter, 29.4mm; range: 6-90.6mm) were included. All of them underwent both contrast-enhanced single-source DECT and contrast-enhanced abdominal MRI within three months. Late arterial phase CT imaging was performed with dual energies of 140 and 80kVp. Protocol A showed monoenergetic 65keV images, and protocol B presented MD-iodine images. Three radiologists qualitatively evaluated randomized images, and lesion detection, characterization, and reader confidence were recorded. Liver-to-lesion ratio (LLR) and contrast-to-noise ratio (CNR) were assessed on protocol A, protocol B, and MRI. Paired t-tests were used to compare LLR, CNR, and the number of detected lesions.Results: LLR was significantly increased in protocol B (2.8±2.33) compared to protocol A (0.77±0.55) and MRI (0.61±0.66). CNR was significantly higher in protocol B (0.08±0.04) compared to protocol A (0.01±0.01) and MRI (0.01±0.01). All three observers correctly identified more liver lesions using protocol B vs protocol A: 83.13% vs 63.64%, 84.57% vs 68.09%, and 79.37% vs 65.52%. There was no significant difference between the three observers in classification of a lesion as benign or malignant. However, higher diagnostic confidence was reported more frequently by the experienced radiologist when using protocol B vs protocol A (84.6% vs 75%).Conclusion: MD-iodine images in DECT help to increase the conspicuity and detection of hypervascular liver lesions. [ABSTRACT FROM AUTHOR]

Based on the characteristics of secondary electron emission, the former formulae for the maximum yield of metals and primary range in the energy range of eV, relation among secondary electron escape probability , average energy required to produce an internal secondary electron , , primary energy of ( and parameter was deduced. On the basis of and the former formula for , relation among mean escape depth of secondary electrons emitted from metals , atomic number , back-scattering coefficient , material density , , atomic weight and was deduced. According to the deduced , the formula for the ratio of to and experimental ratio of to , relation among , original work function and were empirically obtained. According to the characteristics of metal surface, , and , the formula for as a function of , , , , and and that for as a function of , and were deduced, respectively. The influences of surface change on and were analyzed. Calculated and were compared with the corresponding experimental ones. It was concluded that the deduced formulae for and can be used to estimate and , respectively. [ABSTRACT FROM AUTHOR]

Open pore porosity of spaghetti was measured by helium (He) gas pycnometer and mercury (Hg) porosimetry and it was observed as 0.025 and 0.023, respectively. Pore size distribution curve from mercury porosimetry indicated two sharp crests, at alternate position of 59±8 μm and 6.4±0.9 μm diameter pore; while Scanning Electron Microscopy (SEM) showed two types of pores, first class was cracks and second one was holes. The average width of the cracks (channel) and diameters of holes were determined as 3.6±1.5 μm and 1.0±0.3, respectively. The moisture sorption isotherm of spaghetti was measured by dynamic sorption method and modeled by Brunauer-Emmett-Teller (BET) and Guggenheim-Anderson-de Boer (GAM) models. The values of BET monomolecular layer were observed as 3.24 and 5.91 kg water/kg dry solids, respectively for adsorption and desorption cycles. [ABSTRACT FROM AUTHOR]

For cellular bodies with uniform cell size, wall thickness, and shape, an important question is whether the same volume of material has the same effect when arranged as many small cells or as fewer large cells. To answer this question, for finite element models of periodic structures of Mooney-type material with different structural geometry and subject to large strain deformations, we identify a nonlinear elastic modulus as the ratio between the mean effective stress and the mean effective strain in the solid cell walls, and show that this modulus increases when the thickness of the walls increases, as well as when the number of cells increases while the volume of solid material remains fixed. Since, under the specified conditions, this nonlinear elastic modulus increases also as the corresponding mean stress increases, either the mean modulus or the mean stress can be employed as indicator when the optimum wall thickness or number of cells is sought. [ABSTRACT FROM PUBLISHER]

Objective. Differentiation of breast tissues is challenging in X-ray imaging because tissues might share similar or even the same linear attenuation coefficients μ . Spectral computed tomography (CT) allows for more quantitative characterization in terms of tissue density ( ρ ) and effective atomic number ( Z eff ) by exploiting the energy dependence of μ . The objective of this study was to examine the potential of ρ / Z eff decomposition in spectral breast CT so as to explore the benefits of tissue characterization and improve the diagnostic accuracy of this emerging 3D imaging technique. Approach. In this work, 5 mastectomy samples and a phantom with inserts mimicking breast soft tissues were evaluated in a retrospective study. The samples were imaged at three monochromatic energy levels in the range of 24-38 keV at 5 mGy per scan using a propagation-based phase-contrast setup at SYRMEP beamline at the Italian national synchrotron Elettra. Main results. A custom-made algorithm incorporating CT reconstructions of an arbitrary number of spectral energy channels was developed to extract the density and effective atomic number of adipose, fibro-glandular, pure glandular, tumor, and skin from regions selected by a radiologist. Significance. Preliminary results suggest that, via spectral CT, it is possible to enhance tissue differentiation. It was found that adipose, fibro-glandular and tumorous tissues have average effective atomic numbers (5.94 ± 0.09, 7.03 ± 0.012, and 7.40 ± 0.10) and densities (0.90 ± 0.02, 0.96 ± 0.02, and 1.07 ± 0.03 g cm -3 ) and can be better distinguished if both quantitative values are observed together., (Creative Commons Attribution license.)