Powder Characteristics Research Articles

Residual mass prediction of powder discharged from hopper at non-gravity directions

Residual powder often occurs when the hopper is inclined, which leads to material waste and reduces utilization efficiency. This paper carried out hopper discharge experiments of fine glass beads at non-gravity directions with hopper tilted from vertical to horizontal. The powder residual mass at different discharge directions was first analyzed. The criterion equation of powder residue was established in combination of experimental observation and force analysis, based on which the effect of the operation conditions on the utilization rate of powder was discussed. Second, based on the morphological characteristics of residual powder, the integral equation for calculating volume was established. Meanwhile, the error caused by the slip phenomenon was corrected. Finally, the residual mass prediction model was established. The model demonstrates precise prediction outcomes This study provides a reference for improving the utilization rate of powder in the aspects of hopper structure setting, powder flow properties, and discharge directions matching.

Advancements and Perspectives in Additive Manufacturing of Tungsten Alloys and Composites: Challenges and Solutions

This review explores additive manufacturing (AM) for refractory tungsten (W) and its alloys, highlighting the primary challenges and determining factors in the AM of pure W, W alloys and composites. The challenges mainly arise from W’s high melting point, low laser absorptivity, high thermal conductivity, high melt viscosity, high oxygen affinity, high ductile-to-brittle transition temperature, and inherent embrittlement, which lead to defects and anomalies in AM-produced parts. This review focuses on both processes and alloying strategies to address the issues related to densification, micro-cracking, and the resultant properties in W-based components. Cracking in additively manufactured W remains a persistent issue due to thermal stress, embrittlement, and oxide formation. Powder characteristics, process parameters, and thermal management strategies are crucial for W densification. Throughout the review, existing knowledge and insights are organized into comprehensive tables, serving as valuable resources for researchers delving deeper into this topic. Future research in W-AM should focus on understanding the interaction between AM process parameters and microstructural and material design. Advances in atomic-level understanding, thermodynamic modeling, and data analytics have the potential to significantly enhance the precision, sustainability, and applicability of W-AM.

Low-abrasive air-polishing powders—characteristics and application in clinical practice. A review

Low-abrasive air-polishing powders—characteristics and application in clinical practice. A review

Optimization of lyoprotectant for recombinant human acidic fibroblast growth factor by response surface methodology

Recombinant human acidic fibroblast growth factor (rh-aFGF) is a widely used biological product, but it is unstable and its biological activity is easy to decrease. In order to maintain the long-term stability and biological activity of rh-aFGF, based on the response surface method, the freeze-drying characterization and cell proliferation rate of rh-aFGF freeze-dried powder were evaluated by scoring and Methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay in this study. The optimal concentrations of trehalose, glycine and BSA were optimized, and the optimal formulation was verified by regression experiment. The results showed that trehalose, glycine and BSA had significant effects on the characterization of lyophilized rh-aFGF and cell proliferation. The optimal formulation of 5.7% trehalose, 2.04% glycine and 1.98%BSA combined with rh-aFGF could achieve the optimal freeze-dried characterization and biological activity. Using the best formulation to verify, the freeze-dried formability index of the freeze-dried powder was 23.35, and the rate of cell proliferation was 43.59%, which was close to the expected 23 and 41.69%. This study determined a freeze-dried formulation of rh-aFGF that meets the requirements of freeze-dried formalization integrity and maintains biological activity, providing reliable support for the subsequent development of related drugs.

Effects of non-covalently bound polyphenols/vitamins on the structure and functional characteristics of egg yolk powder

The egg yolk powder (EYP) was modified in this study by incorporating the tea polyphenols (TP), rosemary extract (RE), curcumin (CC), ascorbic acid (AA), and vitamin E (VE) to create the complex of polyphenols/vitamins-EYP. The structure, flavor, and emulsification properties of the complex were investigated. The results demonstrated that the addition of these five substances enhanced the flavor of EYP. Among them, VEP (EYP modified by VE) exhibited the flavor profile closest to EYP, while TPP (EYP modified by TP) had the most different flavor compared to EYP. This was because VE could induce secondary and tertiary structural changes in EYP and exposed more functional groups for binding with volatile flavor compounds such as hexanal, 1-octen-3-ol, and benzaldehyde, thereby improving the overall flavor of EYP. However, due to its larger molecular weight (1099.62 Da), VE exhibited the limited degree of interaction with EYP, thereby enabling it to preserve the overall flavor profile of EYP. On the other hand, TP possessed most active hydroxyl groups, which easily interacted with EYP, forming new complexes that significantly altered its flavor characteristics. Among the five modified powders, VEP had the highest emulsification, but it was still lower than that of EYP. This was because the particle size of VEP (1592.75 nm) was higher than that of EYP (821.88 nm), which was not conducive to the rapid movement to the oil-water interface, resulting in the reduced emulsification.

Research on Improving Moisture Resistance of Asphalt Mixture with Compounded Recycled Metallurgical Slag Powders.

The utilization of steel slag as an alternative material in asphalt mixtures is considered the solution to the problem of the shortage of natural aggregates. However, asphalt mixtures with steel slag show susceptibility to damage caused by moisture, especially in powder form. Therefore, blast furnace slag powders were used to compound with steel slag powders as fillers to improve the moisture resistance of asphalt mixtures. The characteristics of the steel slag powders and blast furnace slag powders were investigated initially. Subsequently, the adhesion properties of the asphalt mastics with the powders to the aggregates were evaluated. Finally, the moisture resistances of the asphalt mixtures were identified. The results indicate that the steel slag powder exhibited a notable prevalence of surface pores, which had a more uniform size distribution. In contrast, the blast furnace slag powder exhibited a greater average pore size. The larger specific surface area of the steel slag powder was over 30% larger than that of the blast furnace slag powder, and the superior gelling activity of the blast furnace powder enhanced the adhesion property. Both the steel slag powder and blast furnace slag powder were found to enhance the adhesion properties of the asphalt mastics, while the effect of the steel slag powder was more pronounced, the maximum force difference of which exceeded 200 N. The antagonistic effect of the steel slag powder and blast furnace slag powder on the resistance of the adhesive interface to moisture damage was confirmed by the contact angle test. The incorporation of the blast furnace slag powder markedly enhanced the moisture resistances of the asphalt mixtures. The phenomenon of dynamic moisture damage to the asphalt mixtures was more pronounced under the multicycle times, obviously severer than that in a stable water environment. As the dynamic moisture cycles increased, the degree of destruction gradually approached a steady state.

Recovery and Characterization of Calcium-Rich Mineral Powders Obtained from Fish and Shrimp Waste: A Smart Valorization of Waste to Treasure

With the increase in global aquaculture production, managing waste from aquatic biomass has become a significant concern. This research aimed to develop a sustainable valorization approach for recovering calcium-rich fish, including mackerel tuna and pangas bone and shrimp shell powders. The powders were characterized by various physicochemical and nutritional parameters, including proximate composition, amino acids, protein solubility, water holding capacity (WHC), oil holding capacity (OHC), and heavy metal contents. Color analysis and structural examination were carried out using field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), and Fourier-transform infrared spectroscopy (FT-IR), and in vitro radical scavenging activity was assessed. Significant protein content was observed in the powders, which was highest in shrimp shell powder (SSP) at 37.78%, followed by 32.29% in pangas bone powder (PBP) and 30.28% in tuna bone powder (TBP). The ash content was consistent in PBP and TBP at around 62.80%, while SSP had a lower ash content of 36.58%. Amino acid analysis detected 14 different amino acids in the recovered powders. Notably, SSP demonstrated the highest WHC and OHC values (2.90 and 2.81, respectively), whereas TBP exhibited the lowest values (1.11 for WHC and 1.21 for OHC). FE-SEM revealed the compact structure of TBP and PBP, contrasting with the porous surface of SSP. EDX analysis indicated higher calcium (24.52%) and phosphorus (13.85%) contents in TBP, while SSP was enriched in carbon (54.54%). All detected heavy metal concentrations were within acceptable limits. The recovered powders demonstrated significant ABTS free radical scavenging activity. The findings of this study suggest the suitability of the recovered powders for various food and pharmaceutical applications.

A Review on the Production and Characteristics of Cheese Powders.

Cheese powder is a product resulting from the removal of moisture from cheese. At first, cheese emulsion is prepared by dissolving cheese(s) with water and calcium sequestering salts followed by drying. The desirable characteristics of cheese powder are high solubility, no lumps, storage stability, and imparting a typical cheesy flavor to the final product. Many current studies on cheese powder are focused on reducing calcium-sequestering salts (CSSs) to reduce the sodium content of cheese powder. This review discusses the production processes and physio-chemical properties of cheese emulsions and powders, aiming to enhance current understanding and identifying potential research gaps. Furthermore, strategies for producing cheese powder without CSSs, including pH adjustment, homogenization, and addition of dairy components such as buttermilk powder and sodium caseinate, are elaborated upon. Processing variables such as heating conditions during the preparation of cheese emulsion may vary with the type and age of the cheese used and product formulation. These conditions also effect the characteristics of cheese powders. On the other hand, producing a stable cheese emulsion without CSSs is challenging due to impaired emulsification of fat. The combined use of buttermilk powder and sodium caseinate among various alternatives has shown promising results in producing cheese powder without CSSs. However, future research on replacing CSSs should focus on combining two or more strategies together to produce cheese powder without CSSs. The combination of pH adjustment and dairy ingredients and the use of novel processing technologies with different ingredients are interesting alternatives.

The effect of LaSi2 content on the powder characteristics and coating structure of ZrB2-SiC

To investigate the effect of LaSi2 content on the properties of ZrB2-SiC composite powder and coatings, different amounts of LaSi2 were added to the ZrB2-SiC system. The composite powders were prepared using the induction plasma spheroidization process, and the coatings were fabricated using atmospheric plasma spraying. Results showed that LaSi2 significantly improves the density of both the powder and the coatings. As LaSi2 content increase to 15 vol%, the density of the powders increases to 2.75 g/cm3 and the porosity of the coatings decreases to 6.92 %. Our results suggest that LaSi2 can fully melt in the plasma jet field and act as a sealing phase to heal pores, thereby improving the performance of both the powders and subsequently, the coatings.

Circularly Polarized Luminescence from Pure and Eu-Doped Trigonal TbPO4·nH2O Nanocrystals.

In this contribution, we describe the preparation, by means of a precipitation reaction from aqueous solution at 40 °C, and the structural characterization of nanocrystalline powders of trigonal Tb1-xEuxPO4·nH2O (with x = 0, 0.005, 0.01, 0.05, and 0.1; n tentatively assigned as 0.67) which crystallize in the two possible P3121 or P3221 enantiomorphic space groups. While the volume of the crystal lattice is not significantly affected by the Tb3+/Eu3+ substitution, the average crystallite size seems to depend on the Eu3+ dopant concentration and ranges from 13 to 30 nm. The desired handedness of the crystals has been induced by using, during the synthesis, one of the two possible enantiomers of tartaric acid (l or d). The analysis of the luminescence excitation and emission spectra, together with the decay kinetics of the 5D4 Tb3+ excited state, suggests the presence of a very efficient Tb3+ → Eu3+ energy transfer process in the Eu3+-doped orthophosphates. Upon excitation of Tb3+ ions at 368 nm, the enantiomorphic powders grown with l- or d-tartaric acid (i.e., l-TbPO4·0.67H2O/d-TbPO4·0.67H2O, l-Tb0.995Eu0.005PO4·0.67H2O/d-Tb0.995Eu0.005PO4·0.67H2O, and l-Tb0.9Eu0.1PO4·0.67H2O/d-Tb0.9Eu0.1PO4·0.67H2O) exhibited mirror circularly polarized luminescence signals in the visible spectral region (in the green and/or in the red).

A Comparative Evaluation of Powder Characteristics of Recycled Material from Bronze Grinding Chips for Additive Manufacturing.

In the manufacturing process of ship propellers, large quantities of grinding chips are generated. These grinding chips result from the finishing of the blade surfaces after the primary casting process of the propeller. The aim of this study was to investigate and compare different preparation processes used to produce chip powders with sufficient powder quality for the additive manufacturing process of directed energy deposition. The preparation of the samples was performed through different sieving, milling and re-melting processes. For the characterization of the prepared samples, powder analysis according to relevant industry standards was carried out. It was found that the re-melting processes result in superior powder quality for additive manufacturing in terms of particle size, morphology, and flowability. For some characteristics, the powder exhibits even better properties than those of commercial powders. Furthermore, the powder properties of the milled samples demonstrate a promising potential for use in additive manufacturing.

Investigation of the rehydration characteristics of dairy and infant formula powders using focused beam reflectance measurement and electrical resistance tomography

The potential of focused beam reflectance measurement (FBRM) and electrical resistance tomography (ERT) was evaluated as on‐line process analytical technologies (PAT) for monitoring powder rehydration. Skim milk powder (SMP) and stage one infant formulas were evaluated. Among all samples, SMP had the greatest conductivity by ERT (P < 0.05), this was confirmed by off‐line methods, that is, SMP had a higher solubility, whereas infant formulas had lower solubility. Particle counts for fines of all samples reached peak values ~450 s. Results demonstrated PAT tools offer capability for rehydration characterisation of dairy and non‐dairy powders.

Spark plasma sintering of boron carbide (B4C): From characterisation to finite element modeling of sintering

Boron carbide (B4C), known for its unique properties, presents challenges in reaching its full density with sintering process due to low diffusion coefficients. This study explores the application of Spark Plasma Sintering (SPS) to overcome these challenges and enhance the understanding of its impact on pure B4C ceramics. The study outlines a comprehensive methodology for developing an SPS sintering model. Starting with a summary of conducted studies, powder oxidation analysis, characterization methods, and dilatometry curves processing, the article details the derivation of constitutive parameters based on the Skorohod-Olevsky theory. Isothermal profiles at different temperatures, variation in heating regimes, and a stepwise approach for SPS pressure application form the basis of the derivation methods. A grain growth model is developed for a comprehensive simulation of sintering, incorporating microstructural analysis and parameter derivation. Finally, the article addresses the integration of this mechanical sintering model with thermal and electrical considerations into a finite element method (FEM) software for a holistic SPS modeling. Thermo-electrical considerations, including the Peltier effect, are also computed, providing a well-rounded understanding of the SPS process for B4C ceramics. This study contributes valuable insights to optimizing the SPS parameters to achieve enhanced densification and microstructure control in B4C ceramics.

Predicting hardness of graphene-added Si3N4 using machine learning: A data-driven approach

This study presents a data-driven framework based on machine learning (ML) using extreme gradient boosting (XGBoost) for predicting the hardness of silicon nitride (Si3N4) ceramics reinforced with graphene. The XGBoost model takes into account various factors such as graphene type and content, characteristics of the raw Si3N4 powder, the parameters of the sintering process (sintering technique, temperature, pressure, holding time), and the characteristics of the sintered samples, i.e., the density, αβ content and Vickers hardness. The parameters that influence the Si3N4 hardness most strongly are identified, with sintering pressure, sintering time and density being the most influential. The addition of graphene content up to a certain threshold (1 wt%) has a positive impact on hardness. However, beyond that it leads to a lower density and a lower mechanical performance. Sintering parameters, particularly the sintering pressure, temperature, holding time and technique, strongly affect the density, final grain size, αβ Si3N4 composition and subsequently the hardness. The study highlights the importance of density and the densification process in achieving high hardness in Si3N4 ceramics. The developed ML model provides a valuable tool for predicting the hardness of Si3N4+graphene ceramics composites and offers insights into selecting suitable graphene type, content, and processing parameters. While the study primarily focuses on Si3N4+graphene composites, this novel approach holds promise for the in-silico design and analysis of diverse ceramic materials.

The Effect of Limestone Powder Characteristics on Sulfate Attack of Cement-Based Materials in Low-Temperature Saline Soil Areas of Northwest China

The Effect of Limestone Powder Characteristics on Sulfate Attack of Cement-Based Materials in Low-Temperature Saline Soil Areas of Northwest China

Some properties of aloe vera gel powder prepared by microwave and oven drying

Abstract Aloe barbadensis Miller is the most bioactive compound used in the food and pharmaceutical industry. This study was conducted to prepare the Aloe gel powder by using an oven and microwave at various temperatures and energy. The objective of this study was to investigate the effect of microwave and oven drying on the physicochemical properties of aloe vera gel powder spesifically antioxidant activity. Some parameters examined were the water content, color, yield, and swelling power. In addition, it also has a higher yield and antioxidant activity with optimal visual performance. The results show that the Aloe gel powder obtained by oven drying meets the water content standard of less than 12% and needs a shorter drying time. This Aloe gel powder even showed a good potency of hydrogel formation, since its swelling property is 3% higher than Aloe gel dried by microwave method. The higher temperature at oven drying of 75 showed color value with the highest L value (brightness). Nevertheless, at microwave drying of 45 W energy had higher antioxidant activity (1.642 times higher) than 75°C. The recommended condition for the drying process of Aloe gel powder is using the microwave at an energy of 45 W for about 3 hours with an average yield of approximately 0,71%. In general, a higher temperature and energy of drying caused more changes in the physicochemical characteristics of aloe vera gel powder.

Research on Evaluation Method of Water-blocking Powder Distribution Uniformity of Buffer Layer in HV Cable Based on Image Processing

Abstract High voltage (HV) cables are widely used in urban power transmission networks. The key component in HV cable, the buffer layer, has attracted lots of attention and more and more researchers are devoting to its material property evaluation and quality test techniques. A longitude water-blocking property evaluation method of buffer layer based on image processing is proposed in this paper. The microscopic images of the buffer layer are enhanced and morphologically processed. The area fraction method, entropy method, and fractal dimension method are used to evaluate the distribution characteristics of buffer layer water-blocking powder in binary images. This article innovatively proposes a more economical and convenient simulation method that can efficiently and accurately evaluate the waterproof performance of the buffer layer of high-voltage cables. With the proper use of the buffer layer, it can effectively protect the cables and improve the stability of power system operation.

Optimization of maltodextrin concentration and spray drying temperature on physicochemical characteristics of powdered edamame milk

Peeled edamame can be processed into a product that will increase added value, including edamame milk. The perishable nature of milk requires further processing, such as drying it into powder. One of the commonly used fillers is maltodextrin because it can improve the product’s physical properties. With this treatment process, the physicochemical characteristics could be changed. Therefore, this study aimed to optimize the treatment of the physicochemical characteristics of edamame milk powder. Response Surface Methodology (RSM) with Central Composite Design (CCD) experiment with maltodextrin concentration factor (5.71%-10.00%) and spray drying temperature (160°C-215°C) was used in this study. Analysis of physicochemical characteristics carried out included water content, water activity, solubility, hygroscopicity, and color (a(-)). The results showed that treatment with the combination of 6.00% maltodextrin and 215 °C of drying temperature offer the optimum condition in producing a high-quality edamame milk powder.

Phytochemical Evaluation and Comparative Study of Marketed Ajwain Ark Formulations

Background: A study has been conducted on ajwain (Trachyspermum ammi), a herb with therapeutic properties. Two formulations, SATVYK ark (made with water) and PURNDHENU ark (using cow urine as a solvent), have been compared. Objectives: The research includes evaluating the macroscopic and microscopic characteristics of ajwain seeds; Hence, this article involves the phytochemical evaluation of Ajwain seeds and other qualitative evaluation aspects such as TLC of two different marketed ajwain ark formulations. Methods: TLC was obtained using Toluene: Ethyl acetate (9.3:0.7, v/v/v) as mobile phase and Silica gel plates as stationary phase. Based on these there is a comparative study of these two marketed ark formulations with MINITAB software version 19. Result: Macroscopic evaluation, microscopic evaluation and powder characteristics of seeds of Trachyspermum ammi (L.) Sprague were performed and Physico-chemical parameters of two different marketed ark formulations were also evaluated. Using various chemical tests Preliminary phytochemical analysis has been carried out. Conclusion: The method suggests both formulations are viable, leaving the choice dependent on factors like patient preferences and therapeutic goals.

Preparation and microwave absorption property of Ni/Al powder

As a functional composite material, nickel-coated aluminum powder has been widely used in conductive fillers, electromagnetic shielding materials and other fields due to its advantages of low density, high conductivity and low cost. In this paper, nickel-plated aluminum powder was prepared by a sodium hypophosphite system. The effects of different nickel coating amounts (the percentage of nickel-plating quality to nickel-plated aluminum powder quality) on the morphology, phase, compaction resistivity and electromagnetic parameters of nickel-plated aluminum powder coating were studied. The X-Ray Diffraction (XRD) results proved the successful preparation of nickel-coated aluminum powders with different nickel coating amounts. The Scanning Electron Microscope (SEM) images clearly show the coating effect under different nickel coating amounts. By plating nickel on the surface of aluminum powder, the surface characteristics of aluminum powder are changed, so as to adjust its conductivity, resistance, stability and other properties, thus affecting its electromagnetic performance and wave absorption performance. The results show that the comprehensive absorbing performance is excellent when the nickel coating amount is 40%. The reflection loss of the sample with a thickness of 2.0[Formula: see text]mm is less than [Formula: see text][Formula: see text]dB in the frequency range of 10.17–12.38[Formula: see text]GHz. When the frequency is 10.72[Formula: see text]GHz, the minimum reflection loss reaches [Formula: see text][Formula: see text]dB.