Types Of Powders Research Articles

Comparing the Effectiveness of Photoluminescent Powders for the Development of Latent Fingerprints on Complex Surfaces

Since the end of the 19th century, criminal investigation began to use the invisible impressions of the fingerprints that people leave on the crime scene to relate them to suspected criminal acts. To make them visible, different technologies have been developed over the last 120 years. One of them is the use of physical powders, and within this group it is also possible to identify different types of powder. Photoluminescent powders (fluorescent and phosphorescent) have a specific application for those surfaces considered “complex”. This research will investigate the quality of these two types of developers on different surfaces to weigh up the advantages and disadvantages of prioritizing the use of each one of them.

Effect of powder recycling on inclusion content and distribution in AISI 316L produced by L-PBF technique

AISI 316 L stainless steel is widely used as material to produce components by means of additive manufacturing. To increase the circular economy, the powders are collected and re-used after the printing process, thus the effect of powder recycling on microstructure and properties of printed components is of the utmost importance. This work focused the attention on non-metallic inclusions by examining virgin and recycled powders, and products printed by using both types of powders in a laser powder bed fusion (L-PBF) process.Recycled powders exhibit an irregular shape due to fragmentation, spatters and satellites and, compared to the virgin ones, have a higher gas (O, H and C) content. Both powders contain non-metallic inclusions with a larger quantity in the recycled ones.The printed samples have a similar microstructure, however those produced by using recycled powders exhibit voids of larger size and a little greater amount of inclusions. XRD and EDS examinations of inclusions extracted from the metallic matrix showed that they consist of a mix of amorphous and crystalline silica. Large part of these particles are already present in virgin powders and only a minor part forms during repeated printing operations. Accordingly, the quality of virgin powders is the factor that mainly affects the inclusion content of printed products indicating that the powder production process is the most critical stage of the whole manufacturing process.

Microplastics in infant milk powder

Microplastics can be found almost everywhere and extensively expose to human. Infants are vulnerable, and the potential risks of microplastics may be greater for infants, however, infants' microplastic exposure is still poorly understood. Since milk powder makes up a significant portion of many infants’ diets, we investigated microplastic pollution in infant milk powder and calculated the microplastic exposure from milk powder, feeding bottles and milk powder preparation. On one hand, we studied 13 different types of milk powder with different packaging, processing systems, and milk sources. The boxed milk powder (7 ± 3 items/100 g) was more polluted with microplastics than the canned milk powder (4 ± 3 items/100 g). The inner packaging of the boxed milk powder was plastic and aluminum foil laminated, it emitted 8 ± 2 to 17 ± 1 items/100 g of microplastics, and might be a main source of microplastics in boxed milk powder. On the other hand, we found that when infants consume milk powder, the microplastic exposure from milk powder itself is little, exposure from feeding bottles is 6.8 times higher than that from milk powder and milk powder preparation is 1.7 times higher.

Experimental investigation of WC-12Co cold sprayed: Substrate hardness, bonding mechanism, powder type

Effects of substrate hardness and particle type on a single WC-12Co (Tungsten carbide cobalt) particle's deposition behavior during the cold spray process was investigated in this study. SEM was used to analyze the surface and cross-sections of the deposited particles to determine their morphology. It was discovered that the deposition behavior of WC-12Co particles changed with increasing substrate hardness, going from fully embedding into soft substrate to partially flattening and even rebounding from the hard substrate. Spherical microstructured WC-12Co particles sustained more severe deformation than other types of powder because of the smaller WC size. The porosity value of WC-12Co coatings is lower, at 1.18 %. WC-12Co particles bulk properties remained unchanged since there were no microstructural changes, decarburization, or the formation of fragile phases.

The effect of process temperature and powder composition on microstructure and mechanical characteristics of low-pressure cold spraying aluminum-based coatings

The effect of operating gas temperature and powder type on microstructure and mechanical characteristics of cold spraying coatings deposited on EZ33A-T5 magnesium alloy was studied. Three aluminum-based cold spraying powder mixtures Al + Zn, Al + Al2O3 and Al + Zn + Al2O3 were used for the investigation. Deposition was performed using D423 low-pressure cold spray system at operating gas pressure of 1.0 MPa and different temperatures –300 °C, 450 °C, and 600 °C. The coatings microstructure was investigated with optical and scanning electron microscopy. Mechanical properties of the coatings were characterized through standard test methods for adhesion and cohesion strength, and standard test methods for Vickers hardness of thermal spray coatings. The results demonstrate that with increasing initial gas temperature at spraying nozzle inlet from 300 °C to 600 °C, an increase in the porosity of the coatings of all investigated powder mixtures can be observed. Microstructure characterization showed an increase in porosity from 2.3% to 4.1% for Al + Zn powder mixture, from 2.1% to 3.5% for Al + Al2O3 powder mixture, and from 2.5% to 5.6% for Al + Zn + Al2O3 powder mixture. The minimum porosity was obtained at 450 °C for all investigated powder mixtures. Adhesion and cohesion strength and microhardness of coatings were reach their maximum value at 450 °C. The best performance was obtained for Al + Al2O3 powder mixture: coating adhesion—31.9 MPa (was limited by the bonding strength of the glue), cohesion—93.5 MPa, microhardness—81 HV0.15. The influence of Al2O3 particles in the powder mixture on the above-mentioned parameters was also established. The results show that the presence of ceramic particles in powder mixtures can positively effect porosity level and mechanical characteristics.

Optimization and Performance Evaluation of Steel Slag Asphalt Mixture Modified with Fibers under Freeze–Thaw Cycles

Recycling waste steel slag for asphalt pavement construction can reduce energy consumption and preserve nonrenewable natural resources. However, the moisture susceptibility of steel slag asphalt mixture (SSAM) in severe freeze–thaw regions should be taken into consideration. In light of this, three types of fibers (basalt fiber, polyester fiber, and lignin fiber) and rubber powder were blended into the SSAMs, and their freeze–thaw damage characteristics were investigated. First, the optimum bitumen and fiber content of SSAMs were determined based on Marshall design using response surface methodology. Then, the air voids of SSAMs were identified through X-ray computed tomography (CT) technology, while the effects of the fiber and freeze–thaw cycles on the moisture stability of SSAMs were investigated. Moreover, the enhancement effects of the fibers were analyzed using scanning electron microscopy (SEM). The results show the optimum fiber content of different fiber-reinforced SSAMs are 0.35%, 0.29%, and 0.23%, respectively, and the optimum bitumen content is 6.7% for all cases. The effect of freezing–thawing leads to an increase of the air voids in the middle part of the specimen, whereas the incorporation of fibers weakens the adverse action of freezing–thawing and effectively improves the moisture stability of the SSAMs. Furthermore, the network structure formed by basalt fibers in asphalt mastic significantly improves the integrity of the SSAM. Additionally, basalt fiber reinforced SSAM shows the best resistance to moisture damage.

Fabrication of Spark Plasma Sintered Spark Plasma Sintered Transparent Alumina Using Magnesium Oxide and Lanthanum Oxide as Sintering-Assisted

In this research, the fabrication of transparent Alumina was done by spark plasma sintering (SPS). Two types of alpha and gamma Alumina powders with particle size of 200 and 50 nm were used, respectively. The sintering assisted materials used in this research were magnesium nitrate and lanthanum nitrate, each of which was used 100 ppm using a chemical precipitation process. Calcination was performed at 800°C and the resulting powders were subjected to SPS at 1500 °C with a rate of 50 °C/min for 15 minutes under a pressure of 70 MPa. The phase composion was analyzed by X-ray diffraction (XRD) before and after SPS. The morphology of the powders and the microstructure of the sintered samples were studied using scanning electron microscopy (SEM). The bulk density was obtained to be 3.94 gr/cm3 and 3.9 gr/cm3 in the alpha and gamma samples, respectively. The UV-Visible transmission test showed 20% transmission in the alpha alumina sample. The amount of IR transmission in the alpha and gamma samples was obtained to be 65% and 25%, respectively. The alpha alumina sample had a higher transmission percentage and density compared to the gamma sample.

The Concept of WC-CrC-Ni Plasma-Sprayed Coating with the Addition of YSZ Nanopowder for Cylinder Liner Applications.

In the article, the new concept of plasma-sprayed coatings for the cylinder liner was presented. The new type of powder containing WC-CrC-Ni with a 5 and 10 wt. % addition of nano-YSZ powder was plasma-sprayed on aluminum 2017 alloy samples. The selection of optimal plasma-spraying parameters was made taking into account the thickness, porosity, and hardness of the coatings. For the coatings obtained according to the developed parameters, the analysis of their microstructure, chemical, and phase composition was performed. At the next stage, the friction coefficient of the developed coatings was tested and compared with the properties of a classic cast-iron cylinder liner. The obtained results suggest that the developed type of coating might be used for cylinder liner applications after a deeper friction analysis.

Potential of Local Fruits (Kersen (Muntingia calabura), Kawista (Limonia acidissima) and Trembesi (Samanea saman) as Sweetener with Low Glycemic Index and Glycemic Load

Diabetes is a metabolic disease that occurs in a person characterized by hyperglycemia. One of the cause of diabetes melitus is excessive consumption of simple sugar, so it is necessary to replace sugar (sucrose) with natural sweteeners derived from sweet fruit such as kersen, kawista and trembesi. This research is an experimental study to make natural sweeteners from kersen, kawista and trembesi fruit powder. The natural sweeteners of kersen, kawista dan trembesi fruit powder were analyzed for protein, fat, dietary fiber, ash, water, and carbohydrates. The solubility tests was carried out by the AOAC method, brix with refractometry, sugar content by spectrophotometry, organoleptic properties by hedonic test. The natural sweetener of trembesi fruit powder was analyzed glycemic index by the method of Wolever et al. (2001) and glycemic load was calculated from glycemic index test of food taking into account the amount of carbohydrates available in the serving size. There was a significant difference (p<0,05) in solubility, brix index, total sugar, sucrose content, organoleptic preference level moisture, ash, fat, protein, and carbohydrate content among the three types of fruit powder but there was no significant difference (p>0,05) on the dietary fiber and reducing sugar content. The glycemic index and glycemic load value of trembesi fruit powder were 29,09 and 7,09. Natural sweeteners from trembesi fruit powder has highest carbohydrate content compared to kersen and kawista fruit powder. Natural sweetener from trembesi fruit powder has low glycemic index (29,09) and glycemic load (7,09).

Improving the Usage Properties of Steel Using Cold Spray Deposition: A Review

In this paper, the improvement of the characteristics of different steels that are subjected to extreme operating conditions, including the steels used in the manufacture of various military components, the AISI 52100, the manufacture of bearings, and other types of parts that are also subjected to severe operating conditions were analyzed regarding cold spraying, which uses different types of powders to increase the performance of the materials. The cold, thermal spraying technology “Cold Spray” is a method of processing particles in a solid state. Thermal spraying, based on the dynamic increase in gas acceleration up to supersonic speeds, leads to the obtainment of high kinetic energies, and the accelerated particles are deposited at values that are below their melting point. Research conducted through cold spray technology has seen a significant improvement in material properties; when processing the particles in a solid state, they adhere to the surface instead of eroding it. Cold spraying has proven to be an effective technique for improving material properties, as confirmed by its integration into different fields and industries, becoming competitive by being the only method for depositing particles below their melting point.

Performance enhancement of modified asphalt via coal gangue with microstructure control

The efficient application of coal gangue into asphalt pavement materials not only improves pavement service performance, but also relieves environmental pressure of accumulation. However, the compatibility of coal gangue powder with asphalt pavement materials promises further strengthens, calling for enhanced processing schemes of coal gangue. Firstly, modified materials were successfully prepared by modulating the coal gangue powder. A series of microscopic experiments were conducted to characterize the phase structure, microstructure, thermal stability, adsorption capacity, and functional group change characteristics of different types of coal gangue powder. Then, three kinds of coal gangue powders were applied to the matrix asphalt by melt blending method, and the composite's rheological properties and aging resistance were also studied. Finally, the modification mechanism of the composite was discussed from the micro level. The research showed that the specific surface area of intercalated and activated coal gangue powder increased about 1.45 times and 1.25 times, respectively, compared with ordinary coal gangue powder. The physical adsorption capacity of gangue powder can be improved by chemical intercalation or high-temperature activation. The high-temperature resistance and anti-aging performance of asphalt can be affected by enhancing the interaction between coal gangue powder and the asphalt matrix. The design of coal gangue modified asphalt materials with different structural characteristics promotes the development of sustainable and durable pavement.

Experimental investigation of the catalyst-free reaction characteristics of micron aluminum powder with water at low and medium temperatures

Aluminum metal has a high energy density and can react with water to produce hydrogen instantly, which is environmental-friendly and safe. Aluminum has great potential to provide a good carrier for energy and hydrogen storage. The utilization of aluminum is constrained by the oxide layer on its surface. In order to promote the aluminum-water reaction to continue efficiently, the reaction needs to be activated. The modification of aluminum is often complicated and dangerous, and it is difficult to apply the hydrogen produced by the reaction and the heat released. The increase of temperature and pressure of the reaction has also been proved as a useful activation method. Continuous reactions are difficult to achieve at high temperature and pressure, and it becomes difficult to obtain reaction initiation and development processes. However, the reaction process has an essential impact on the utilization of the aluminum-water reaction. In this paper, the aluminum-water reaction process at medium temperature was investigated using micron aluminum powder. The effects of initial temperature, particle size of aluminum powder and water type on the reaction were further analyzed. In addition, the kinetic analysis of the aluminum-water reaction was carried out to obtain kinetic models. Experimental results indicate that the product of the aluminum-water reaction is Al(OH)3 at 90–150 °C. The reaction initial temperature shows a multipolar effect on the reaction between aluminum and water. The hydrogen yield from the reaction between ∼25 μm aluminum powder and tap water at 150 °C is 31.9 %. The pre-exponential factor and apparent activation energy increase with the reaction proceeding. The present research is conducive to further safe and efficient utilization of micron aluminum powder for energy conversion, and benefits the achievement of carbon peaking and carbon neutrality.

Effects of chemical additives and mature compost on reducing nitrogen loss during food waste composting.

This study is aimed at adding different types of mature compost and sulfur powder, as additives into food waste composting to investigate the effect on nitrogen loss and compost maturity. The composting experiment used the in-vessel composting method and was conducted continuously for 15days. High-throughput sequencing was used to analyze the bacterial community during composting. Results showed that the secondary fermentation mature compost mixed with sulfur powder group had the most reduction of ammonia emission (56%) and the primary fermentation mature compost amendments were the most effective for nitrous oxide emission reduction (37%). The temperature, pH, and nitrogen forms of transformation of the pile significantly affect the nitrogen loss during composting. Firmicutes helped to promote the rapid warming of the pile, and Actinobacteria and Proteobacteria played an important role in decomposition of organic matter. Thermobifida and Ureibacillus had a main contribution to the rapid degradation of organic matter in the process of composting. The relative abundance of nitrogen-fixing bacteria was higher, and the relative abundance of predominantly ammonifying and denitrifying bacteria was lower than the control group, with the addition of different additives.

Near-Infrared (NIR) Silver Sulfide (Ag2S) Semiconductor Photocatalyst Film for Degradation of Methylene Blue Solution.

A silver sulfide (Ag2S) semiconductor photocatalyst film has been successfully synthesized using a solution casting method. To produce the photocatalyst films, two types of Ag2S powder were used: a commercialized and synthesized powder. For the commercialized powder (CF/comAg2S), the Ag2S underwent a rarefaction process to reduce its crystallite size from 52 nm to 10 nm, followed by incorporation into microcrystalline cellulose using a solution casting method under the presence of an alkaline/urea solution. A similar process was applied to the synthesized Ag2S powder (CF/syntAg2S), resulting from the co-precipitation process of silver nitrate (AgNO3) and thiourea. The prepared photocatalyst films and their photocatalytic efficiency were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and UV-visible spectroscopy (UV-Vis). The results showed that the incorporation of the Ag2S powder into the cellulose films could reduce the peak intensity of the oxygen-containing functional group, which indicated the formation of a composite film. The study of the crystal structure confirmed that all of the as-prepared samples featured a monoclinic acanthite Ag2S structure with space group P21/C. It was found that the degradation rate of the methylene blue dye reached 100% within 2 h under sunlight exposure when using CF/comAg2S and 98.6% for the CF/syntAg2S photocatalyst film, and only 48.1% for the bare Ag2S powder. For the non-exposure sunlight samples, the degradation rate of only 33-35% indicated the importance of the semiconductor near-infrared (NIR) Ag2S photocatalyst used.

Study of nanodiamond photocathodes for MPGD-based detectors of single photons

The proposed new Electron–Ion Collider poses a technical and intellectual challenge for the detector design to accommodate the long-term diverse physics goals envisaged by the program. This requires a 4π detector system capable of reconstructing the energy and momentum of final state particles with high precision. The Electron-Ion Collider also requires identification of particles of different masses over a wide momentum range.A diverse spectrum of Particle IDentification detectors has been proposed. Of the four types of detectors for hadron identification, three are based on Ring Imaging Cherenkov Counter technologies, and one is realized by the Time of Flight method. The quest for a novel photocathode, sensitive in the far vacuum ultraviolet wavelength range and more robust than cesium iodide, motivated an R&D programme to explore nano-diamond (ND) based photocathodes, started by a collaboration between INFN and CNR Bari and INFN Trieste. Systematic measurements of the photoemission in different Ar:CH4 and Ar:CO2 gas mixtures with various types of ND powders and Hydrogenated ND (H-ND) powders are reported. A first study of the response of THGEMs coated with different photocathode materials is presented.The progress of this R&D programme and the results obtained so far by these exploratory studies are described.

Application Research of Low-density Polypropylene Materials on Door Trim Panels

Lightweight design is an important indicator in the process of automobile development, including product structure design, using plastic instead of steel and low density materials and other technical solution, this paper studies low density material technology to achieve lightweight automotive parts. The material system of polypropylene (PP)/elastomer/talc blends(PP+EPDM-TD)was selected to study the combination of different types of PP (homopolymer PP and random PP) and talc powder (mesh number and content) in the material formula. With the goal of the performance of the door panel parts, PP materials with 5% (PP+EPDM-TD5), 10% (PP+EPDM-TD10) and 20% (PP+EPDM-TD20) talc content were developed to verify the material properties. 10% and 20% talc content can meet the requirements. Then, the two materials were comprehensively evaluated from the aspects of parts forming analysis, size verification and application cost, and the low-density material (PP+EPDM-TD10) was finally selected for application to meet the lightweight design requirements of parts.

Comparison of physicochemical properties of three types of bamboo shoot powders

Powders were prepared from fresh Phyllostachys pubescens bamboo shoots (P. pubescens), Dendrocalamopsis oldhami bamboo shoots (D.oldhami) and Dendrocalamus latiflorus bamboo shoots (D.latiflorus), and their physical, chemical, adsorption and powder properties were determined. All three of these powders were high in dietary fiber and protein, with P. pubescens powder containing the highest concentration of dietary fiber (50.34 ± 0.65 g∙100 g-1). The water holding, oil holding, and swelling capacities of this powder were all higher than those of the other two kinds of powders. The P. pubescens powder also showed the highest capacity to adsorb glucose, cholesterol and nitrite. In addition, the measured repose and slip angles of this powder were lower than those of the other two powders, indicative of it having good fluidity. And the bulk density and tap density of this powder were significantly higher than those of the others as well, indicative of its superior filling property.

A Comparative Study on Surface Change by Silica Filler of Epoxy Resin Used for Conservation Treatment of Stone Cultural Heritage

This study aimed to relieve the stress on outdoor stone cultural heritages that undergo frequent re-conservation treatment owing to the surface change and discoloration of treated areas. To this end, we selected and prepared 19 types of silica fillers as research samples. Half of the surface of each sample was processed, and the accelerated aging test was conducted in accordance with KS M ISO 4892-2. Changes in chromaticity, luster, powderization, pore and crack formation, and roughened surface bluntness depending on the type of silica powder and surface processing applied were determined before and after the test. Comparative studies revealed that the roughened surface of the filler sample made of high-quality amorphous silica (A1), which was mixed with angular and spherical particles, had excellent color and luster stability, with a ◿E*ab of 0.54 (Mean: 9.91) and ◿GU of –0.07 (M: 25.10) respectively; changes in its other properties were negligible. The results of this research indicate that the sustainability of treated areas can be extended by applying favorable conditions during conservation treatment.

Sensory Profile of Cocoa Powder Using Analytical Hierarchy Process

Cocoa powder comes with various attributes in its taste affecting consumer acceptance. The analytical hierarchy process (AHP) approach can be used to identify the effect of each attribute on the sensory profile of cocoa powder. This present study used the AHP approach to determine the degree of importance of sensory attributes on several types of cocoa powder and find the type with the best sensory profile. Cocoa powder comes from cocoa beans made through fermentation and non-fermentation process. In addition, we used non-fermented cocoa powder treated with water and incubated at 45oC for 4, 8, and 16 hours later named as incubated cocoa powder. Then, the sensory attributes of fermented cocoa powder were used as the reference in assessing the sensory profile of incubated cocoa powder, including the one going through the treatment. The sensory analysis performed by trained panelists revealed 11 attributes that made up the flavor profile of cocoa powder. Of these 11 attributes, only 4 were considered primary attributes with a high degree of importance, including chocolate (23.7%), sweet (19.9%), caramel (11.8%), and nutty (10.9%). Other attributes had a lower degree of importance, including creamy (7.4%), fruity (6.5%), green (5.4%), flowery (4.8%), astringent (4.5%), bitter (3.1%), and acid (2.2%). AHP also ranked the incubated cocoa powder based on the similarity of the flavor profile with fermented cocoa powder. Nonfermented cocoa powder without treatments fell into the lowest rank, while nonfermented cocoa powder with treatments fell into a higher category in the following order: 8 hours > 16 hours > 4 hours. To summarize, AHP can be used in decisionmaking affected by many factors. AHP has been proven effective in determining the sensory profile of cocoa powder, especially in choosing the attribute withthe highest effect. In addition, AHP helps determine the best treatment for incubated cocoa powder to produce the most similar sensory profile to fermented cocoa powder.

Determination of shear behavior of magneto-rheological elastomers under harmonic loading

Magneto-rheological (MR) materials can respond reversibly and quickly under the effect of an external magnetic field. MR materials contain micron-sized iron particles. These iron particles are typically dispersed in an elastomer or a liquid. These materials due to their properties constitute a kind of smart material in terms of engineering material. Such materials are used as isolators in various engineering applications, structures, and sound control subsystems. This study aimed to determine the mechanical properties for shear behavior of MR materials for under harmonic loading. Parameters such as matrix materials with different hardness values, powder types, magnetic field, frequency, and deformation were studied. The parameters related to the MR material itself were analyzed with the obtained data. The present study reveals that considering the sensitivity to magnetic field parameter, composite materials having the most suitable properties were produced with Shore 2 hardness value and SQ magnetic powder. It had been observed on increase about 200% at the rate of Shore A10 and A2 as a result of comparing the hardness scale. Also according to the powder rate while there was an increase on worth effect of relative MR, it is seen that the biggest increase had been in SQ powder with 199% worth. When looked some studies in literature, about comparing different hardness values such as matrix materials powder types etc. there aren’t any studies. The state of magnetic field thinks that features such as MR effect, Storage, and Loss modulus haven’t been examined yet.