Properties Of Powders Research Articles

Sustainable Concreting: Optimization Modelling of the Strength Properties of Bio-Self Compacting Concrete Incorporating Sporosarcina Pasteurii, Calcined Clay and Limestone Powder

Sustainable concreting is prerequisite for infrastructural development in developing countries so as to meet up with the sustainable development goal of adequate mass housing and other critical infrastructure. Thus, research is ever ongoing aimed at developing cheaper and more durable concrete via the incorporation of bio-based by-products in concrete to improve its properties, as well as optimizing the quantities of these secondary materials for maximum and optimal concrete production. One such revolutionary concrete that is yet to find full application in the developing world is self-compacting concrete, because of the cost and attendant environmental effects. There is thus a need to arrive at optimal materials quantities that can maximize concrete properties without recourse to many trial and error experimentations that are both time and resources consuming. The application of modelling tools in concrete technology aids in the optimization of concrete constituents for optimal self-compacting concrete performance. This research uses optimization techniques to optimize the bacteria dosage as well as model the Compressive and Tensile strength properties of a calcined clay and Limestone powder blended ternary self-compacting concrete using sporosarcina pasteurii as Microbial induced calcite precipitation agent and calcium lactate as nutrient source. The Bacteria was incorporated into the concrete at a bacterial content of 1.5x108cfu/ml, 1.2x10 cfu/ml and 2.4x109cfu/ml corresponding to the McFarland turbidity scale of 0.5, 4 and 8 while the nutrient (calcium lactate) content was 0.5, 1.0 and 2.0% by weight of cement for each bacterial content. The Compressive strength and tensile strengths at 28 days were determined and the results used for both the model development, strength optimization and model validation, with the strengths as the dependent variable (y) and the bacterial content corresponding to a McFarland scale of and calcium lactate content as the independent variables, X1 and X2 respectively. The results show an improvement in the compressive strength from 32N/mm2 to 45.2N/mm2 at the optimal bacterial and nutrient content of 1.2x10 cfu/ml and 0.5% respectively, and tensile strength from 4.01N/mm2 to 5.0N/mm2. Also, the non-linear regression models proved adequate for optimizing the bacterial content for optimal self-compacting concrete performance. Journal of Engineering Science 15(1), 2024, 11-19

Effects of ultrafine grinding on nutritional, physicochemical and protein composition of Acheta domesticus powder

Acheta domesticus is a new source of high-quality protein, but the accessibility and acceptability of protein is notably limited by the particle size of the house cricket powder, and little information about the effect of particle size on the house cricket powder had been reported. In this study, four kinds of ultrafine cricket powder were obtained by two industrial methods, and compared with the traditional grinding powder. The results illustrated that ultrafine grinding technology could increase the powder properties, such as the thermal stability, crystallinity, color brightness, protein extraction rate and amino acid content, especially the essential amino acid (EAA) content were significantly improved. And the properties and nutrient release of the powder are mainly related to the particle size rather than the method. The results have a certain guiding effect on the development and application of ultrafine house cricket powder as a multifunctional nutrient.

Characterization of Freeze-dried Pumpkin Powders: Powder Quality and Nutrient Stability

Being a good source of nutrients, viz., ascorbic acid, β-carotene, phenols, and antioxidants, pumpkin pulp (Cucurbita moschata) can be utilised as a functional ingredient in many food products by converting them into a more stable product like pumpkin powder. Hence the present study is focused on the production of freeze-dried pumpkin powder by two different methods (drying in petri plates with 5mm sample thickness and in 250 ml flask). The moisture content and water activity were reduced by 92.50% and 74.73%, respectively, compared to the fresh pumpkin pulp, indicating safe storage limits. Freeze-dried pumpkin powders exhibited a decrease of 25% ascorbic acid, 21.58% β-carotene, 39.39% reduction in total polyphenols and 72.98% in antioxidant content. The powder properties of the developed freeze-dried powders exhibited water activity of 0.4aw to 0.35aw bulk density of 0.15 to 0.12 g cm-3, and flow ability of 18.39° to 22.74°.

Proximate Analysis and Techno-Functional Properties of Berberis aristata Root Powder: Implications for Food Industry Applications.

Berberis aristata, commonly known as Indian barberry, has been traditionally used for its medicinal properties. Despite its recognized pharmacological benefits, its potential application in the food industry remains underexplored. This study aims to investigate the proximate analysis and techno-functional properties of Berberis aristata root powder to evaluate its feasibility as a functional food ingredient. The root powder of Berberis aristata was subjected to proximate analysis to determine its moisture, ash, protein, fat, fiber, and carbohydrate content. Techno-functional properties, including water and oil absorption capacity, emulsifying and foaming properties, and bulk density, were evaluated using standardized analytical techniques. The proximate analysis revealed a high fiber content and a significant number of bioactive compounds. The root powder exhibited favorable water and oil absorption capacities, making it suitable for use as a thickening and stabilizing agent. Emulsifying and foaming properties were comparable to conventional food additives, indicating their potential in various food formulations. The findings suggest that Berberis aristata root powder possesses desirable techno-functional properties that could be leveraged in the food industry. Its high fiber content and bioactive compounds offer additional health benefits, making it a promising candidate for functional food applications. Further research on its incorporation into different food matrices and its sensory attributes is recommended to fully establish its utility.

Mechanical, freeze-thaw resistance and heavy metals leaching properties of alkali-activated recycled concrete powder solidified sludge

Solidified sludge was an efficient method to consume the large amount of sludge, which can be used as the subgrade filler in road engineering. However, the traditional solidified materials, such as cement and lime, consumed a large amount of natural resources and increased carbon emissions. This study used the alkali-activated recycled concrete powder (ARCP) to solidify sludge, which could be used as a potential subgrade stabilization filler. The optimal factors of ARCP were firstly determined by orthogonal test according to the compressive strength. Then the influences of different ARCP dosage, sludge moisture content and curing method on the mechanical properties, freeze-thaw resistance and heavy metals immobilization of the ARCP solidified sludge (ARCPS) were investigated. At last, microstructures of ARCPS were analyzed by SEM, XRD and TG-DTG tests. The experimental results demonstrated that the optimal mixture for ARCP: the silicate modulus of 1, liquid-solid ratio of 0.48 and calcium hydroxide content of 3 %. The solidified process by ARCP improved the mechanical properties and freeze-thaw resistance of ARCPS greatly. The 7 d unconfined compressive strength of ARCPS could reach 1305–2033 kPa when the sludge moisture content was 15 %, which meet the requirement of 500 kPa from the Chinese standard. The frost heaving rates of ARCPS were between non-frost heaving and mild frost heaving. The sludge moisture content was the most important factor affecting the freeze-thaw resistance of ARCPS. The properties of ARCPS were further improved after carbonation curing. The leaching mass concentration of heavy metals decreased significantly after the solidification of sludge. After 5 freeze-thaw cycles, the heavy metal leaching concentration increased but was still met the requirement of standards. SEM results showed that the surface of carbonated ARCPS was covered by dense scale-like carbonation products, which further enhanced the strength and freeze-thaw resistance of ARCPS. The results can be used to guide the application of sludge and ARCP in construction.

Assessment of High-Temperature Oxidation Properties of 316L Stainless Steel Powder and Sintered Porous Supports for Potential Solid Oxide Cells Applications

Assessment of High-Temperature Oxidation Properties of 316L Stainless Steel Powder and Sintered Porous Supports for Potential Solid Oxide Cells Applications

Effect of Al2O3 coating on the properties of Si3N4 ceramics prepared by vat photopolymerization

The preparation of Si3N4 ceramics by vat photopolymerization (VPP) has motivated increasing research interest. However, it is challenging to prepare Si3N4 ceramics by VPP due to the high UV-light absorbance and refractive index of powder. In this paper, a method for Al2O3-coated Si3N4 powder was proposed. Combined with the boehmite-coated and high-temperature treatment, Al2O3 was successfully coated on the surface of Si3N4 powder. The effect of Al2O3 content on the properties of Si3N4 powders, slurry and the sintered Si3N4 samples were investigated. The Al2O3 coating layer not only improves the curing forming ability of Si3N4 slurries, but also can directly act as one of the sintering aids of Si3N4 ceramics. The bulk density of the samples decreases from 3.04 ± 0.02 g/cm3 to 2.97 ± 0.01 g/cm3 with the increase of coating content, while the porosity increases from 5.38 ± 0.89 % to 7.54 ± 0.63 %. The sample of 5 wt % Al2O3 coating content has the maximum flexural strength of 474.28 ± 16.38 MPa and the highest relative density of 94.62 ± 0.89 %. This work can not only obtain a great modification effect, but also promote the dense sintering of Si3N4 ceramics during subsequent stages, which provides a constructive method for modifying Si3N4 powders to achieve photopolymerization.

Enhanced soft magnetic properties of SiO2-coated FeSiCr magnetic powder cores by particle size effect

Abstract It has been known that metal FeSiCr powders with large average particle sizes have been typically employed to prepare magnetic powder cores (SMCs), with few studies reported on the influence of magnetic properties for original powders with various average particle sizes less than 10 μm. In this work, SiO2-coated FeSiCr SMCs with different small particle sizes were synthesized using the sol–gel process. The contribution of SiO2 coating amount and voids to the soft magnetic properties was elaborated. The mechanism was revealed such that smaller particle sizes with less voids could be beneficial for reducing core loss in the SMCs. By optimizing the core structure, permeability and magnetic loss of 26 and 262 kW/cm3 at 100 kHz and 50 mT were achieved at a particle size of 4.8 μm and ethyl orthosilicate addition of 0.1 mL/g. The best DC stacking performance, reaching 87%, was observed at an ethyl orthosilicate addition rate of 0.25 mL/g under 100 Oe. Compared to other soft magnetic composites (SMCs), the FeSiCr/SiO2 SMCs exhibit significantly reduced magnetic loss. It further reduces the magnetic loss of the powder core, providing a new strategy for applications of SMCs at high frequencies.

Microstructure and mechanical property of high-density 7075 Al alloy by compression molding of POM-based feedstock

Metal injection molding of aluminium alloy (MIM-Al) attracts attention, owing to the lightweight, corrosion resistance and good thermal conductivity. However, it is hard to fabricate high-quality MIM-Al due to the hard-to-sinter powder and poor mechanical properties. Here, we report a facile compression molding process for fabricating high-density 7075Al alloy parts using polyformaldehyde (POM)-based feedstock. Pressureless sintering with a high nitrogen flow rate was adopted to promote sintering densification process. The wetting behavior, rheological properties, and morphology of the feedstock were characterized, showcasing the shear-thinning behavior and suitable viscosity for POM-PP-SA binder. Through controlling the compact pressure, mold temperature and holding time, green gear part with good shape retention and dense microstructure was achieved. Influence of process factors and sintering temperature on the microstructure and mechanical properties of 7075Al alloy are investigated. Remarkably, the aluminum alloy components sintered at 610 °C exhibited excellent performance, with a relative density reaching 97.6 % and a tensile strength of 214.8 MPa. This achievement provides a foundation for the industrial application of complex-shaped aluminum alloy components through the compression molding process.

Optimizing nitrite content in powders from plasma-activated egg whites for meat preservation using response surface methodology

The study optimized the production of powders from two types of egg whites to be used as a nitrite source for meat curing, establishing a maximum utilization limit of 2%. The necessary quantity of nitrite was established through response surface methodology to guarantee its efficacy as a preservative agent and adherence to regulatory standards. High R2 values (0.9946 for hen, 0.9962 for ostrich) validated critical factors: plasma treatment time and distance, with minimal impact from drying temperature. Under specific experimental conditions (155.93 min, 16.84 cm, 41.10 °C), obtained nitrite concentration of 4000 mg kg⁻1 was confirmed through experiments. Stability tests showed that nitrite levels remained stable over four weeks under different conditions including vacuum and air-sealed packaging, as well as different temperatures (−18 °C, 4 °C, and 26 °C). Future research should investigate long-term stability, the formation of additional compounds, and the functional properties of powders to confirm their potential for food applications.

차전자피 분말(Psyllium husk Powder)의 영양성분 및 차전자피 분말을 첨가한 머핀의 이화학적 특성

차전자피 분말(Psyllium husk Powder)의 영양성분 및 차전자피 분말을 첨가한 머핀의 이화학적 특성

Efficient Improvement of Eugenol Water Solubility by Spray Drying Encapsulation in Soluplus® and Lutrol F 127.

Herein, we present an elegant and simple method for significant improvement of eugenol water solubility using the polymers Soluplus® and Lutrol F 127 as carriers and spray drying as an encapsulation method. The formulations were optimized by adding myo-inositol-a sweetening agent-and Aerosil® 200 (colloidal, fumed silica)-an anticaking agent. The highest encapsulation efficiency of 97.9-98.2% was found for the samples containing 5% eugenol with respect to the mass of Soluplus®. The encapsulation efficiencies of the spray-dried samples with 15% eugenol are around 90%. Although lowering the yield, the addition of Lutrol F 127 results in a more regular particle shape and enhanced powder flowability. The presence of Aerosil® 200 and myo-inositol also improves the rheological powder properties. The obtained formulations can be used in various dosage forms like powders, granules, capsules, creams, and gels.

Efficacy of Qi-Gen powder for immunity enhancement and investigation of its therapeutic mechanisms through gene expression profiling

Infection with different viruses threatens the health of animals in the livestock and poultry industry. Immunopotentiators can increase natural immunity and vaccination efficacy; however, most are expensive chemical and biological compounds with questionable safety. Traditional Chinese medicines (TCMs) such as Yupingfeng (YPF), a well-known immunomodulatory remedy, provide healthy alternatives to such agents. The aim of this study was to examine the therapeutic properties of Qi-Gen powder (QG) and compare them with those of YPF. The immune organ index, cytokine levels, and other indicators were utilized to evaluate the effects of QG in an immunosuppression mouse model. QG was further assessed for its ability to enhance vaccine effectiveness in chickens immunized for Newcastle disease virus (NDV). Potential therapeutic mechanisms and targets of QG were examined in the breast cancer cell line MCF-7 using microarray technology combined with the TCM systems pharmacology database of known targets. Compared with model controls, QG improved immunological function, outperforming YPF in mice. QG also enhanced the immunological response to NDV vaccine in immune organs and increased feed intake of chickens. Further research is needed to validate the link between the PI3K/Akt/GSK-3 pathway and the immune-boosting effects of QG.

Optimizing the properties of seashell ash powder based concrete using Response Surface Methodology

Optimizing the properties of seashell ash powder based concrete using Response Surface Methodology

Research Progress on Laser Powder Bed Fusion Additive Manufacturing of Zinc Alloys.

Zinc, along with magnesium and iron, is considered one of the most promising biodegradable metals. Compared with magnesium and iron, pure Zn exhibits poor mechanical properties, despite its mild biological corrosion behavior and beneficial biocompatibility. Laser powder bed fusion (LPBF), unlike traditional manufacturing techniques, has the capability to rapidly manufacture near-net-shape components. At present, although the combination of LPBF and Zn has made great progress, it is still in its infancy. Element loss and porosity are common processing problems for LPBF Zn, mainly due to evaporation during melting under a high-energy beam. The formation quality and properties of the final material are closely related to the alloy composition, design and processing. This work reviews the state of research and future perspective on LPBF zinc from comprehensive assessments such as powder characteristics, alloy composition, processing, formation quality, microstructure, and properties. The effects of powder characteristics, process parameters and evaporation on formation quality are introduced. The mechanical, corrosion, and biocompatibility properties of LPBF Zn and their test methodologies are introduced. The effects of microstructure on mechanical properties and corrosion properties are analyzed in detail. The practical medical application of Zn is introduced. Finally, current research status is summarized together with suggested directions for advancing knowledge about LPBF Zn.

Effect of surface remelting on the characteristics of IN718 components fabricated using laser powder directed energy deposition

Laser Powder Directed Energy Deposition (LP-DED) fabricated components exhibit poor surface finish, necessitating additional post-processing steps prior to their practical application. Enhancing the surface quality of additively manufactured IN718 specimens through conventional post-processing methods is particularly challenging, given the material’s poor machinability and the complexity of the fabricated components. The current study is centered on comprehending the impact of Laser Surface Remelting (LSR) on the surface properties of Laser Powder Directed Energy Deposited (LP-DED) IN718 material. To gain insights into how remelting influences surface characteristics, remelting was carried out using various sets of parameters. The remelted zone exhibited a refined grain structure, leading to increased hardness. Moreover, significant reductions in surface roughness and residual stress were observed in the remelted samples. Regression analysis indicated that laser power played a pivotal role, with positive impact on surface finish and depth of influence but a negative impact on residual stress and hardness. Therefore, considering all the comparison metrics, remelting using laser power of 150 W and a scan speed of 1140 mm min−1 were found to yield optimal surface conditions.

Selected Soluble Dietary Fibres as Replacers of Octenyl Succinic Anhydride (OSA) Starch in Spray-Drying Production of Linseed Oil Powders Applied to Apple Juice

The aim of the study was to compare two kinds of soluble dietary fibres in a mixture with OSA-starch as wall components of linseed oil capsules. Comparison was made based on emulsion (droplet size, polydispersity index, and viscosity) and powder properties (outer structure, colour, surface oil content, and encapsulation efficiency). Additionally, linseed oil powders were applied to the food model (apple juice) and the colour, physical stability, and volatile compound profile of fortified juice were determined. Although the obtained linseed oil emulsions with different compositions of polysaccharide components showed some variation in droplet size, polydisperse index and viscosity, their encapsulation efficiency by spray-drying was very high (>98%). The powders produced had a similar structure and low surface oil content, and their 2% addition to apple juice did not change its stability and only slightly decreased its colour lightness and yellowness. However, greater differences in the volatile compounds of obtained juices were observed. Overall, the added powders reduced the volatility of aroma compounds typical of apple juice but introduced propanal and hexanal, especially the powders with the highest OSA-starch share.

Optimization of /locel 101 and Amylum as /illers in Sambiloto (Andrographis paniculata (Burm.f.) Nees.) Capsules /ormulation

Sambiloto (Andrographis paniculata (Burm.f.) Nees.) is an herbal plant that is beneficial for health due to its main chemical component, andrographolide. Sambiloto can be formulated into capsules to make it more practical and comfortable for consumption, mask the bitter taste, and guarantee dosage accuracy. This research aimed to determine the optimal concentration of Flocel 101 and amylum as capsule fillers to achieve the best physical properties of Sambiloto extract capsules. The study was conducted experimentally using 5 (five) formulas (F1, F2, F3, F4, and F5) with various concentrations of Flocel 101 and amylum. A series of tests were conducted on the physical properties of the capsule powder: organoleptic tests, water content, flowability, disintegration time, and average capsule weight. Additionally, quality control was performed by checking for microbial contamination through total plate count (TPC) and yeast and mold count (YMC) tests. The results of this research indicated that the F1 formula provided the best physical properties and met the requirements, with the appearance of a greenish-gray dry powder, water content of 6.88%, flow rate of 20 g/s, disintegration time of 15.5 minutes, average weight of 0.55 g, TPC 250 cfu/g, and YMC <10 cfu/g.

Microstructural and Magnetic Characteristics of Nanocrystalline Sm4ZrFe33 Alloys

This work focuses on the study of the microstructure and magnetic properties of nanocrystalline powders of Sm4ZrFe33, prepared by high‐energy ball milling. The Sm4ZrFe33 compound adopts a monoclinic structure (space group Cm). Upon annealing, these Sm4ZrFe33 samples exhibit notable variations in their extrinsic magnetic properties, closely linked to temperature fluctuations. The investigation delves into the correlation between morphology, grain size and magnetic characteristics. A significant enhancement in coercivity (Hc), remanent magnetization (Mr), and maximum energy product ((BH)max) is observed, primarily attributed to the finer grain structure present in the samples. Particularly noteworthy, among all annealed specimens, the nanocrystalline Sm4ZrFe33 compound annealed at a temperature of Ta = 973 K demonstrates the most promising magnetic properties. This specimen exhibits a coercivity Hc of 18 500 Oe, remanent magnetization (Mr) of 58 emu g−1, maximum energy product ((BH)max) of 5.18 MGOe, Curie temperature (TC) of ≈804 K, and magnetic anisotropy field (Ha) of 115 980 Oe. These research findings pave the way for future investigations and applications in the realm of permanent magnets, spintronic devices, and magnetic recording, utilizing nanocrystalline alloys based on the Sm4ZrFe33 compound.

Novel White Phosphor Bi3+ co-doped SrCeO3: 2 wt% Sm3+ Synthesized via Fuel Excess Gel Combustion Synthesis for wLED Applications.

Co-doping strategy is done if the emission from the activator is relatively low with existing excitation energy. Thus, to enrich the emission from an activator, the sensitizer like Bi3+ is co-doped onto the host and this intermediator transfers its emission energy to the activator. Prior to the study, no investigations had been conducted, marking the foundational exploration of the sensitizer effect within the rare earth-doped SrCeO3 matrix aimed at enhancing luminescence properties. The current study focuses on the innovation of single-phase robust white phosphors, SrCeO3: 2wt% Sm3+: xBi3+ (x = 0 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%) to coat near UV LED chips for high CRI wLED applications. The novel perovskites were synthesized using a low-temperature fuel excess gel combustion method, utilizing citric acid as the fuel and ammonium nitrate as an extra oxidizer. Upon co-doping SrCeO3: 2wt% Sm3+ with bismuth, the impact of changing sensitizer concentration on both the development of crystalline phases, morphology, elemental composition, band gap energy, and the luminescent properties of ceramic powders were explored through X-ray diffraction, FE-SEM, Energy dispersive spectra, UV-visible absorption spectra, and photoluminescence characterization methods. The experimental results revealed the orthorhombic single-phase formation of SrCeO3: 2wt% Sm3+: xBi3+perovskites yielding high crystallinity and luminescence maximum at critical sensitizer concentration 1 wt% Bi3+. Also, the bright white light emission of all the perovskites was confirmed using the CIE color diagram. Thus, nano-perovskite SrCe0.97Sm0.02O3: 1wt% Bi3+ acts as an inevitable direct phosphor coating the near UV chip in LEDs, which can be a great revolution in energy savings applications.