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Honey egg drink is a food with complete nutrition. However, it is easily damaged and its quality changes quickly, both during the transportation process and during the storage process. Decreasing the quality of honey egg drink needs proper handling such as preservation and further processing so that the product reaches the consumer with good quality. Product handling can be done of them by using the drying method. This study aims to examine and analyze the antioxidant activity and physicochemical characteristics of honey egg powder with different drying times. The parameters measured in this study were antioxidant activity, water content, dissolving time, pH value, and yield value. The research design used was a Completely Randomized Design (CRD) using 5 repetitions. the research treatment was drying time (hours) 12, 14, 16, and 18, respectively. The results showed that the different drying times for honey egg powder had a very significant effect(P<0.01) on the pH value. Drying time had a significant effect (P<0.05) on antioxidant activity and moisture content, but had no significant effect (P>0.05) on dissolution time and yield value. Drying for 12 hours can increase antioxidant activity and maintain physicochemical properties. [ABSTRACT FROM AUTHOR]

In this study, the microstructure and mechanical properties of 316L stainless steel produced using 3-D laser engineered net shaping (LENS) in past decades were reviewed. Moreover, processing techniques utilized in making the 316 L stainless steel have been reviewed in this study. In addition, different types of finishing techniques utilized for surface improvement and heat treatment after processing have been reviewed. Advancements in metal additive manufacturing and applications of carbon nanotubes in stainless steel implants are studied in this review. Moreover, recycling of feedstock powder and techniques utilized to analyze the multi scale structure were reviewed in this work. The corrosion factors affecting the 316 L steel has been studied in this review. [ABSTRACT FROM AUTHOR]

Reusing unsintered powders in selective laser sintering (SLS) additive manufacturing is a good practice to reduce cost and waste. This paper investigated on the effect of recycled powder mixture on the mechanical properties of polyamide (PA12) lattice structure. Two types of material composition were used namely pure virgin material and mixed material from mixture of virgin, reheated and recycled polyamide powders. The results from compression test showed that pure virgin material produced superior mechanical properties as compared to mixed material. However, similar proportion was observed with changes in the design parameters of lattice structure when using each material composition. [ABSTRACT FROM AUTHOR]

Ambon banana is a highly consumed banana variety in West Java. However only the fruit flesh is consumed while the peel generally becomes waste. Banana peels are rich in indigestible carbohydrates which are known to have prebiotic activity. Several varieties of bananas have been investigated for their prebiotic activity, but research on Ambon banana is still limited. This research aims to evaluate the prebiotic activity of Ambon banana peel powder. Ambon peel powder with 1% w/v in concentration was examined for its growth stimulation effect on Lactobacillus acidophilus probiotics. SCFAs production was also analyzed using HPLC. The results showed that Ambon banana peel powder has prebiotic activity with the prebiotic activity score of 13.47. Analysis showed the presence of butyrate, propionate and acetate in the L. acidophilus culture enriched with Ambon banana peel powder. The concentration of butyrate, propionate and acetate were 7.27, 1.32 and 0.23 µg/mL respectively. This study confirmed that Ambon banana peel powder could be an effective prebiotic in increasing the growth of the tested probiotics. [ABSTRACT FROM AUTHOR]

Among calcium phosphates, Hydroxyapatite (HA) has become the material of choice and is commonly used in bone implantation and human teeth due to its chemical and crystal structure similar to bone apatite and excellent bioactivity. To date, HA has been successfully prepared from biogenic waste as the calcium precursor via extraction of calcium oxide from eggshells, seashells, animal bones (cow, chicken, fish) and many more via wet method. The dry method has been least preferred due to the tendency of powder contamination and non-homogeneous powder mixing during the mechanochemical activation method. However, with the proper methods, the dry method can be used in producing pure HA on a mass scale. Consequently, this work used a solid-state synthesis approach to produce HA from discarded eggshells, which provided a biogenic calcium precursor in the form of calcium carbonate. The intention was to determine how various ball milling durations affected the microstructure and phase stability of the artificially produced HA generated from eggshells. The eggshells were dried first and then subjected to calcination at 700°C for 2 hours. The eggshells, after being heated to high temperatures, were combined with dicalcium phosphate dihydrate (DCPD) by rotating at 400 rpm for 2, 4, and 6 hours. The powder combination including CaCO3 and DCPD was subjected to heat treatment at 800°C to get pure HA powder. The XRD analysis of the heat-treated powder revealed the successful production of hydroxyapatite (HA) after 2 hours of ball milling and calcination at 800°C. Extending the ball milling period to 4 hours and 6 hours would lead to intense mechanochemical activation, resulting in the powder combination transitioning into a biphasic calcium phosphate (BCP) phase including HA and β-TCP. Furthermore, the image of pure HA powder that was made after two hours of ball milling showed that the powder had a flake-like shape and was less clumped together. The BCP powder produced contained spherical particles that were agglomerated in form. The milling length of the starting materials significantly impacted the phase stability and microstructure of the synthesised calcium phosphate powder generated from eggshells. [ABSTRACT FROM AUTHOR]

The development and application of electrical discharge machining (EDM) has shown to be a beneficial approach when handling sophisticated materials, including superalloys like Hastelloy, Inconel 718, and Ti6Al4V. An improved version of the EDM method called powder mixed EDM hasovercome several intrinsic drawbacks (PMEDM). A thorough understanding of PMEDM, including its process dynamics, the impact of added powders or particulates (based on their nature and properties), its potential as a surface modification technique, its limitations, and opportunities for future advancements, is still elusive, making the switch from EDM to PMEDM an ongoing exploration. The development and application of EDM are beneficial when handling sophisticated materials, including superalloys like Hastelloy, Inconel 718,and Ti6Al4V. An improved version of the EDM method called powder mixed EDM has overcome several intrinsic drawbacks (PMEDM). There is still much to learn about PMEDM, includingits process dynamics, the effects of added powders or particulates (based on their nature and properties), its potential as a surface modification technique, its limitations, and future development opportunities. As a result, the transition from EDM to PMEDM is still being investigated. [ABSTRACT FROM AUTHOR]

The current work includes an experimental investigation into the shear strength of nanosilica reactive concrete beams. The variable studied was the amount of the nansilica, which ranges from 0% to 3% by weight of cement. The mechanical parameters of the concrete mixture, such as splitting, compressive, and flexural strength, were also studied. Four nanosilica reactive powder concrete beams were subjected to a two-point load and evaluated. Estimating shear behavior was used to failure load, crack patterns and failure mechanisms, load-deflection capacity, and strain distribution. The findings indicate that adding nanosilica to the mix improved the mechanical qualities of the cured concrete. The most significant increase in compressive, splitting, and flexural strengths was observed when nanosilica equaled 3 percent, with increases of 31.3 percent, 45.3 percent, and 50 percent, respectively. Adding NS to reactive powder concrete beams improves shear strength by raising the ultimate shear capacity to 25.1% of the reference beam. In addition, the nanoparticles bridge the cementitious materials, improve beams' ductility, and limit fracture development, and delayed failures. [ABSTRACT FROM AUTHOR]

Numerous creative strategies have emerged as an outcome of research on strengthening concrete. The fascinating technology of self-compacting concrete makes it possible to construct in areas of congestion and simultaneously providing concrete the desired strength and durability. The present research article is novel approach to learn the characteristics of M40 grade self-compacting concrete. The properties of self-compacting concrete (SCC) are ascertained from the study and are compared with the EFNARC standards. The incorporation of industrial byproducts as marble powder for fine aggregate replacement at percentages of 5,10,15,20 and 25 on the features of self-compacting concrete is explored vividly. The self-compacting characteristics in the fresh state as slump cone, V shaped funnel and L shaped box test are performed. The hardened characteristics of specimen are also studied, and the observed result values are correlated with that of the 0% marble powder concrete sample. The research findings reveal that the marble dust powder at 15% replacement level resulted in good strength improvements and workability aspects. [ABSTRACT FROM AUTHOR]

In an effort to lessen the amount of cement needed in the manufacturing of concrete, eggshell powder (ESP) was employed in this study as a partial replacement for cement. The study's primary goal was to evaluate concrete's workability and reinforcing qualities, such as flexural, tensile, and shears strength, using different amounts of ESP in place of cement (0, 10, 20, and 30) at various weight percentages. With a goal strength of 40 N/mm2, 36 samples of concrete in total were cast. After 7, and 28 days, a cube sample (150 x 150 x 150 mm) was compressively evaluated, and a cylindrical specimen (200 x 100 mm) was used to assess tensile strength for the same time periods. twisting resistance 100 x 100 x 500 mm of the specimen, cast over the course of 7 and 28 days of cure. The results of the tests revealed that during. Tensile strength improved by 30% with ESP 20%, and after a 28-day cure, ESP 20% reached its maximum strength. Fresh concrete becomes less workable as the percentage of ESP rises. The power of a concert is increased by the usage of ESP. The crucial component of concrete is aggregate. About Annual production of steel slag is 10 million tonnes in India. The study effort has consistently emphasized the utilisation of trash from industries. In the current operation, steel slag is being used to partially substitute coarse aggregate. In the current research, examined is the M40 concrete that substitutes steel slag for the coarse material. Experimental results for the material's compressive strength of 7 and 28, bending resistance, and divided tensile strength daily were obtained. The outcomes were contrasted with typical concrete properties. The study's findings indicated that natural aggregates could be used in place of some steel slag aggregates, with replacement rates of 0%, 10%, 20%, and 30%, respectively. [ABSTRACT FROM AUTHOR]

Celery or Apium graveolens L. is a plant that belongs to the Apiaceae family. The leaves are wide with a pinnately lobed shape. Celery contains an abundance of antioxidants and vitamins including flavonoids, saponins, tannins, apiin, apigenin, choline, asparagine, vitamins A, B, C, and essential oil. Due to its high antioxidants and vitamins, celery has a high potential as a functional food source. However, despite the nutritional benefit, celery has a short shelf-life which only lasted for 2-3 days. Turning celery into powder is an alternative postharvest technology to extend its shelf life and preserve its nutritional content. The overall antioxidants and vitamins are varied depending on the drying treatment of the postharvest technology. Therefore, this research studies the effect of the drying treatment of postharvest technologies on the antioxidants and vitamins of celery The observed drying treatments were dehydration and tray drying as modern methods and sun drying as a conventional method. Different drying temperatures were observed and optimized. The dehydration method at 50°C was found to be the optimum method and the drying temperature. The celery powder produced from the dehydration method at 50°C showed high antioxidant and vitamin C contents, 50.8 µg/ml and 426.27 mg/100 gram, respectively. [ABSTRACT FROM AUTHOR]

Shireeshadi choornam, a topical fine powder, has been described in Ayurveda traditional textbooks as an effective formulation for treating Primary hyperhidrosis (PHH). This formulation shows great potential in alleviating excessive sweating and unpleasant body odors. The symptoms of PHH include excessive sweating on the palms, underarms, soles, and face. However, there is limited research available on the physicochemical and phytochemical analysis of Shireeshadi formulation. In this study, we aimed to investigate the physicochemical and phytochemical characteristics of two variations of Shireeshadi choornam: one without talc (SFP) and the other with talc (SFPWT). Both samples underwent LCMS QTOF analysis. However, only the SFPWT sample underwent physicochemical analysis. The LCMS analysis of both SFP and SFPWT revealed the presence of nine bioactive phytochemical metabolites, namely Harman, alpha-Bergamotenol, beta-Santalene, beta-Bisabolol, alpha-Curcumene, 3-Butylpyridine, alpha-Bergamotene, Prococene II, and alpha-Eudesmol. Upon reviewing the effects of these bioactive phytochemicals, it was found that they can help reduce the symptoms and complications of PHH by blocking the muscarinic receptors on the sweat glands. Additionally, these phytochemicals possess antifungal and antibacterial properties. [ABSTRACT FROM AUTHOR]

In this study, we performed compressive stress-induced shape recovery treatment on Fe-24Mn-5Si-5Cr-4Ni powder-based alloy prepared by mechanical milling with a green sintering technique. Here, the major process control parameters are the sintering temperature and the compaction pressure. Finally, we achieve a maximum shape recovery of 5.27% using a 1200 °C sintering temperature and a 750 MPa compaction pressure as control parameters. The amount of shape recovery was deteriorated due to the intermetallic precipitate of Cr0.19Fe0.7Ni0.11 and bcc ά martensite. The amount of precipitate produced is linked to the concentration of porosity developed as a result of the reduction in compaction pressure. The porosity, crystallite size, and hardness of the various Fe-24Mn-5Si-5Cr-4Ni bulk alloy combinations were investigated as well. [ABSTRACT FROM AUTHOR]

The main objective of the paper is to investigate the continual elimination of Methylene Blue from aqueous solutions through adsorption on a fixed bed column containing Cocoa seeds shell Powder. The properties of Cocoa seeds shell Powder are analyzed with FTIR/SEM/XRD studies. The study considered various parameters, including flow rate (ranging from 1 to 3 ml/min), bed height (1 to 3 cm), & incipient concentration (10 to 50 mg/l). Among the different conditions tested, the highest uptake of Methylene Blue was observed at a flow rate of 3 ml/min, a bed height of 3 cm, and an incipient concentration of 50 mg/l. The breakthrough time decreased from 180 to 80 minutes as the flow rate increased from 1 to 3 ml/min, and the breakthrough curve (BTC) decreased from 245 to 35 minutes with an increase in the incipient concentration from 10 to 50 mg/l. On the other hand, with an increment in bed height from 1 to 3 cm, the breakthrough time improved from 80 to 125 minutes. Experimental data from the column under different conditions were analyzed using various models and the results were found to be satisfactory. Based on the research findings, it can be concluded that Cocoa seeds shell Powder can serve as an effective, low-cost adsorbent with a high capacity for dye uptake. [ABSTRACT FROM AUTHOR]

In this research, coffee beans powder was used as a natural material and their effect was studied as a reinforcement material on the composite material, where epoxy was used as a matrix and a layer of woven glass fibers. The results showed good mechanical properties after adding different weight fractions of (5%,10%,15%,20%,25%)wt of coffee beans powder (C.B). The best results for the mechanical properties were obtained when adding (20 %) C.B, where the ultimate tensile strength was in the value of (47.2) Mpa, the modulus of elasticity in the value of (0.83) GPa, the flexural strength in the value of (61.805) MPa, and the hardness in the value of (79.4) Shore-D, while the highest value of impact strength was at adding (25%)C.B which is (17)KJ/m2. [ABSTRACT FROM AUTHOR]

In this work, a new type of Y2O3−ZrO2 doped aluminide coating was carried out by the pack cementation process at 900oC for 6 hours with different percentages of (1.0, 1.5, and 1.5) wt% nano Y2O3−ZrO2 added to the pack mixture. A Ni-based superalloy (type IN625 type) was coated with pack powder containing: Al as a source of aluminum; NH4Cl as a source of activator; Y2O3-ZrO2 as a source of reactive element oxide; and Al2O3 as a source of filler metal. The microstructure characterization of the coating was performed by SEM and EDS. It was found that the cross section of the coating obtained was uniform and free from cracking. It consists of three layers: the outer layer, the transition layer, and the inter-diffusion zone. The interface zone features a distinct Cr-rich region and a larger diffusion region extending toward the substrate. Based on the microstructural information of the coatings created at different stages of aluminide, it has been determined that the coating growth in the aforementioned process initially occurs predominantly through inward Al diffusion. It is followed by a transitional stage during which both Ni and Al are diffused outward and inward throughout the growth process. The development of the coating is dominated in the latter stages by the outward dispersion of Ni. Surface XRD analysis shows that the phase structures of coatings are: Al1.1Ni0.9, AlNi, Ni11Zr9, and Ni5Y. The highest value of micro-hardness measurement was 1390 HV at 1.5 wt% nanoY2O3−ZrO2 additive. As a result, the Y2O3−ZrO2 coating has higher micro-hardness and the interfacial bonding force between the coating and the substrate. [ABSTRACT FROM AUTHOR]

The utilization of construction materials for thermoelectric energy harvesting is a concept with high potential for practical civil engineering applications. However, common cementitious and alkali-activated materials do not possess favorable thermoelectric properties. Doping of these materials by electrically admixtures ensures a significant enhancement that, however, cannot compete with the thermoelectric properties of special semiconductors. Nevertheless, the design and optimization of construction materials with such an energy conversion ability is meaningful due to the high surface area of large constructions that are exposed to surrounding energy sources (solar energy, industrial waste heat) ensuring a significant gradient between the surface and the temperature in the material. In the paper, the apparatus designed for simple thermoelectric measurements is introduced, as well as an example of measurement performed on the geopolymer composite based on metashale, potassium silicate+hydroxide activator, and graphite powder in the amount of 8 wt. %. [ABSTRACT FROM AUTHOR]

A computational tool based on the open-source software OpenFOAM was designed to simulate the interaction between powder coating guns and metal surfaces during industrial coating. This tool accounts for various factors, such as airflow, movement of coating particles, interactions among particles, and interactions between particles and surfaces, including details like blow-off effects, electrical phenomena like corona formation around electrodes, and how particles get charged in the corona. Enhanced to work with cloud computing technology, this tool can simulate multiple coating scenarios at once, adjusting for different process parameters. Tests for accuracy and relevancy have been carried out, with positive results. This specific study showcases how the tool predicts coating patterns, coating efficiency, and coating uniformity on a U-shaped metal object based on varying mean powder particle diameters. It suggests optimum particle sizes for coating U-profiles both efficiently and uniformly, which is valuable information for commercial powder material suppliers. [ABSTRACT FROM AUTHOR]

The application of nanotechnology plays a very important role as a cooling medium to reduce wear in the machining process and the effectiveness of lubrication using nanomaterials in bio lubricant. In this study, we analyzed the effect of variations in the mass fraction of Nano powder calcium carbonate, namely 0.05%, 0.1%, and 0.15% in bio lubricant as a coolant for Computer Numerical Control (CNC) Turning Machine. The raw material of bio lubricant used is canola oil, while the nanomaterial additives in this study is calcium carbonate synthesized using the Nano Homogenizer Machine and sonication process. Characterizations carried out include SEM, XRD, and FTIR on Calcium Carbonate powder, thermal properties are thermal conductivity, density, and viscosity, while to determine the tribology properties by applying the results of bio lubricant as a cooling medium in the CNC Turning machining process and the specimen results are tested for surface roughness and microstructure. The use of CaCO3 shows the improvement on thermal, tribology properties, and the suspension on the bio lubricant. The best increment in tribology properties and suspension stability was obtained by using variations of CaCO3 at 0.1% compared to other mass fraction variations which were known through the results of surface roughness and microstructure tests have been done. The smallest size of CaCO3 was obtained at 35.4841 nm. The conclusion can also be seen from one of the test results, namely the SEM test, the resulting SEM morphology shows an irregular round or round but irregular. With this result, it is expected that it will affect the thermal properties of the bio lubricant as a cooling medium. [ABSTRACT FROM AUTHOR]

In the present investigations, we exhibit the efficacy of Fe3O4 as a supercapacitor electrode material. The working material Fe3O4 was acquired via recovering waste toner material from printers, followed by an annealing process and magnetic separation a few times to obtain the final product as Fe3O4. The obtained material is used in an electroactive manner and then deposited on a Ni-foam substrate to develop a supercapacitor electrode. A range of characterizations characterized the prepared electrodes' physicochemical characteristics and electrochemical investigations. Herewith, we have investigated the molarity effect of KOH electrolyte on the fabricated electrode. The specific capacitance of the electrode was found to be 363 F/g at 10 mV/s within the wide potential window of 1.4 V. Additionally, the electrochemical cyclic stability of the Fe3O4 electrode occurred to be 98 % after 1000 cycles. This shows recycled Fe3O4 still possesses good properties as electrode material for supercapacitor applications and may encourage repurposing waste toner to restrain electronic trash. [ABSTRACT FROM AUTHOR]

Al-Fe-Cr alloy material is a material that is widely used as a component in the automotive industry, construction, household appliances, aircraft, and others. Where the Al material is combined with the hope of improving the physical and mechanical properties of each material. Recently, the Al-Fe-Cr alloy material has become a candidate material in the development of cladding in the fourth-generation core reactor (Light Water Reactor). In this study, pure Al material was combined with pure Fe and pure Cr material, where in the sample the percentage of alloy powder was Fe = 88%, Al = 10%, and Cr = 2%. The milling process was carried out for 120 minutes. The obtained powder is then pressed to form pellets with a pressure of 20 tons and then sintered at 100°C, 200°C, and 300°C using a furnace. sintering at 300 °C has a higher HRC value and the sample becomes denser than sintering at 200 and 100 °C. The microstructure of the 88% Fe, 10% Al, and 2% Cr alloy shows the presence of impurities including C, Mg, O, Si, Ca, Cl, and Ti. [ABSTRACT FROM AUTHOR]

The study made a metal alloy with an alloy of 80% Fe (9.6 grams) and 10% Cr (1.2 grams) by adding 10% Al (1.2 grams). Then the metal is subjected to temperature variations of 750⁰C, 850⁰C, and 950⁰C. This is done to develop the strength of the alloy when implemented at high temperatures, and research is also carried out to obtain the characteristics of the mechanical hardness properties alloy. The characterization of FeCrAl was carried out after sintering. The manufacture of FeCrAl alloy using powder metallurgy method with temperature variations of 750℃, 850℃, and 950℃ using a furnace machine, and the material composition is Fe 80%, Cr 10%, Al 10%. The samples were characterized using SEM-EDS (Scanning Electron Microscope-Energy Dispersive X-Ray Spectroscopy) and tested for Rockwell hardness. The mechanical alloying process with temperature variations with temperatures of 750℃, 850℃, and 950℃ significantly affects the hardness value of FeCrAl alloy material. The greater the temperature on the metal, the smaller the hardness value obtained on the alloy material. This is shown in the study of the Fe-Cr-Al alloy where the temperature of 750℃ the hardness value is 82.83 HRB. When the temperature rises to 950℃, the hardness value drops to 79.16 HRB. This shows a decrease in the hardness value plus the penetration depth at a temperature of 950℃ to 0.41 mm, which is caused by high temperatures so that the aluminum element evaporates and the porosity value increases, causing the hardness value to decrease. SEM-EDS analysis showed that the most considerable porosity occurred due to the evaporation of the aluminum element due to high temperatures. The highest porosity value was obtained in sample 3 with a temperature of 950℃, which was 0.66%. Adding aluminum to the Fe Cr alloy can change the characterization, and the intensity of the metal can change. [ABSTRACT FROM AUTHOR]

This study aims to obtain substitute material for metal-based bone implants. Apart from several biocompatibility challenges, the metal implant procedure requires two operations during the recovery stage, which bring discomfort to the patients. The material under study is the shells of freshwater snails (Sulcospira). The shell is rich in calcium, which can be processed into hydroxyapatite (HA). Hydroxyapatite is the potential to replace metal implants since it has similar properties to human bone. The research was conducted by grinding the shells using ball milling at a speed of 200 rpm for 15 minutes with four repetitions. Between millings, heating was conducted up to the temperature of 900°C for four hours. The powder coarseness was observed using a vibrating sieve. The characterization was carried out using a Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX). The results show that the calcium content reached 65% after milling four times with an average powder size of 67 µm. The result obtained in this research is better than previous studies, with a 55% calcium level and an average size of 67 µm. [ABSTRACT FROM AUTHOR]

Bio-ceramic powder from chicken egg shells has been made using a planetary ball mill with varied numbers and types of grinding balls and gradual heating. Chicken egg shells powder is used as a precursor for manufacturing Hydroxyapatite (HA) bio-ceramic material. HA is used as a scaffold, bone filler, and metal implant coating. The manufacture of HA powder with a fine size is very well used for making bone grafts. HA, which consists of calcium and phosphate, is the main component of bone. HA sourced from organic materials such as bovine bones, pig bones, fish bones, goat bones, clam shells, egg shells, snail shells, crab shells, and so on. The research was conducted using a ball mill with variations in the number and ball milling. The balls used are agate and stainless steel. Milling will be carried out in two stages in each variation, namely grinding without gradual heating and grinding followed by gradual heating to a temperature of 900°C. Milling was carried out at 200 rpm for 2 hours. Furthermore, the chicken egg shells powder was characterized using a Scanning Electron Microscope (SEM). The results showed that milling using 45 balls effectively reduced powder size. The powder size decreased in the first stage by 175 µm in the second stage to 32 µm. The Stainless Steel grinding ball type is more effective in reducing powder size than the Agate ball type. The difference in powder size between the two types of balls in the first stage was 133 µm and in the second stage was 80 µm. [ABSTRACT FROM AUTHOR]

The effects of tool stiffness on powder die compaction were investigated by performing FEM analysis of the inner flange shape compaction using a Drucker-Prager Cap model. The material parameters of atomized iron and ferrite powders were validated by comparing the results of uniaxial compaction tests with measurement from a die system. The results simulated influence of punch spring back during unloading and ejection. It was found that increasing the lower punch spring back caused a change in the shear stress during unloading and locally increased the residual stress. [ABSTRACT FROM AUTHOR]

Currently, the majority of laser based powder bed fusion of polymers (PBF-LB/P) processes use polyamides, which prevent the components from exhibiting the mechanical characteristics of traditional manufacturing techniques; since there is a deficit of specific materials. Therefore, highly ductile materials are needed to cover further areas of application. The preferred material thereby is polypropylene with its various structures and settings. Available research demonstrates that while isotactic polypropylene can be processed, it has brittle properties that require the use of additional structures. To address this challenge and to exploit the full potential of PBF-LB/P, the first part of this work investigates the material properties in order to make a statement about the process performance, while the second step analyzes the processability and component properties of the heterophasic polypropylene grade. [ABSTRACT FROM AUTHOR]

Additive manufacturing processes offer significant advantages over conventional processes. In particular, there are fewer limits to the design freedom of additive manufacturing processes. In contrast additive manufacturing processes also have disadvantages that must be taken into account. For example, highly filled material systems cannot be processed in additive manufacturing, especially in powder bed-based processes such as selective laser sintering. However, it has already been shown that manufacturing with low-filled material systems can succeed. So far, the main goal has been functionalization with a view to improving mechanical properties on a global scale. In this study, the functionalization possibility with regard to the generation of locally electrically conductive paths by means of an x-y positioning system is to be investigated. In addition to various material systems, copper and solder powders will be used for this purpose. The copper powder is mixed volumetrically with the polyamide 12 powder (PA12) used in the process before discharge to ensure process capability, while the solder powder is used unmixed. The powders are then fed into the nozzle intended for discharge. In order to investigate the influence of the track width on the electrical conductivity, the process parameters of the x-y positioning system are also varied. This allows for an active influence to be exerted on the track geometry in terms of its width. The adjustable parameters include above all the traversing speed, the adjustable height between the powder bed and the nozzle, and the frequency and amplitude of the piezo element. The deposited tracks, which are processed into individual layers in selective laser sintering, are examined by means of microscopy for geometric and morphological formation as well as the connection of the track to the individual layer. The morphological and light microscopic analysis is followed by the examination of the electrical conductivity. [ABSTRACT FROM AUTHOR]

In the field of plastics, powder bed fusion using laser-beam (PBF-LB) represents the most industrially relevant additive manufacturing technique. To increase the productivity of the PBF process, reduced build times are of great interest. Shorter build times are economically desirable, but their influence on e.g., mechanical properties is not fully understood. Densification in PBF-LB of polymers is slow in comparison to metals due to the low ratio of surface tension to viscosity. The application of a subsequent powder layer prior to complete densification of the underlying layer can result in significant residual porosity in the part. On the other hand, faster repeated laser irradiation can lead to higher melt temperatures and thus faster densification. In this study, the influence of the inter-layer time (ILT) on the resulting part properties of poly-amide 12 (PA12) was investigated. For this purpose, experiments were carried out and numerical models were developed and compared. An experimental setup was developed to study the stepwise thickness increase of the first ten layers as well as the mechanical and density properties of multi-layer samples. Numerical simulations were performed complementary to the experimental investigations. Therefore, a simulation tool was developed and implemented for direct comparison with experimental observations. The one-dimensional finite difference solver for this purpose considers laser irradiation and melting of the powder bed as well as heat conduction, densification and crystallization of the polymer melt. Multiple layers can be simulated under realistic process conditions. We found that the competition between the time scales of densification and crystallization on one hand and the ILT on the other hand results in a wide range of porosity profiles. [ABSTRACT FROM AUTHOR]

The effects of process variables like hatch conformity and layer time are often overlooked and, as a result, are not fully understood. This is particularly true for thin-walled components. This work specifically addresses the impact on thin structures, which are critical for maximizing the potential of the laser-based powder bed fusion process. Therefore, tensile specimens of various thicknesses and orientations were manufactured, and the hatch conformity and layer time were altered. For a more profound process understanding, infrared thermography is used to analyze the developing exposure temperatures. While the hatch count indicated an impact on the resulting exposure temperatures, the effect on the resulting part properties is minimal. The layer time shows a notable influence on the part geometry and density. Young's modulus can be described as constant when considering the mechanical properties, independent of the layer time and hatch conformity. The elongation at break does not influence the hatch conformity but the layer time. Overall, the most significant changes occurred due to variations in the part thickness and must be considered in part optimization. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the effects of using new banana fibre and aluminium oxide as natural fillers in glass fibre reinforced polymer (GFRP). Substances and Techniques: Using a hand lay up approach, we create polymer composites in three groups (two experimental and one control). Twenty samples were taken from each group. The hardness is tested using a Barcol Hardness Machine, while tensile strength is determined by a Universal Testing Machine (UTM) (BMU). Tensile strength is measured using ASTM-D638 and hardness is measured using ASTM-D785. There were sixty people in total in the sample. G power test was performed to determine the optimal sample size for each group; these values were 80%, 5%, and 95%, respectively. Using SPSS-V26, we found that the findings were statistically significant at the 0.000 p0.05 level. The tensile strength of GFRP reinforced with aluminium oxide and unique banana fibre was found to be substantially greater than that of GFRP. In comparison to GRFP, the unique banana fibre GRFP and aluminium oxide blended material's hardness was noticeably greater. Results showed that compared to untreated GFRP, the tensile strength and hardness of composites made with alkaline-treated natural fillers such as aluminium oxide and unique banana fibre were significantly improved. [ABSTRACT FROM AUTHOR]

Powder Mixed EDM (PMEDM) is a refined form of EDM in which finely ground powder that is conductive is added to the dielectric. Particles suspended in dielectric reduce the insulating properties of the material, increasing the inter-electrode gap, and thereby improving EDM performance and surface quality compared to conventional EDM. More recently, studies had been conducted on the use of mixed-powder dielectric to improve EDM's efficiency. Many scientists have become interested in PMEDM in recent decades. Including a metallic particle in the dielectric fluid not only makes it more conductive but also increases the gap between the workpiece and the tool that causes sparks. When powder is mixed into dielectric, material removal speeds up, surface quality improves, and tool wear is reduced. Particle attributes such as concentration, electrical conductivity, density, and size have an impact on processing variables and should be taken into account when choosing a powder for an operation. Researchers can use this review to better select powders for the PMEDM process by learning how different powders affect the process in question. [ABSTRACT FROM AUTHOR]

Steel-fibre reinforced polymer (FRP) composite bar (SFCB) is a novel form of rebar. The main technique for SFCB manufacturing, which is described briefly in this paper, is a manual technique, and this study cast eight slabs using this procedure to investigate the flexural behavior of SFCB-reinforced concrete slabs by comparing them with concrete slabs reinforced with ordinary steel bars. The study included an investigation of changes in the thickness of slab, the effects of the CFRP sheet length wrapped around the steel bars, and concrete compressive strengths. The outcomes showed that, increasing the slab thickness from 80 to 100 mm led to an increase in the ultimate load capacity of 55%, while utilising SFCB reinforcement enhanced the ultimate load capacity, with maximum percentage increases ranging from 23% to 41%. Furthermore, the results showed that replacing NC with RPC offered slight enhancements in the ultimate load: this was about 12% in the control slab, while when SFCB was used, the improvement was 16%. Finally, a length of reinforcement two-thirds of the full length of the bar was found to be the optimum length when used for strengthening. Within this paper, the methodology and results are first outlined, then a brief conclusion offered with regard to the investigation overall. [ABSTRACT FROM AUTHOR]

The article substantiates the feasibility of producing a dry plaster mixture based on a lime-sand mixture, which is an intermediate product in the production of sand-lime brick. The results of a study of the influence of an additive - redispersible polymer powder on the structure and properties of a plaster mortar based on a lime-sand mixture - are presented. It has been established that when the content of redispersible polymer powder is 2.5% by weight of the dry mixture, almost complete filling of the pores in the hardened plaster mortar with a polymer binder is achieved, which leads to the achievement of its required performance characteristics. [ABSTRACT FROM AUTHOR]

Research of graphite powder based on coconut shell fabricated using modified temperature treatment has been successfully conducted. Coconut shell as a raw material was washed from the husk and dried in the oven with three different temperature variations, i.e. 31°C, 51°C, and 71°C for 17 hours, so that three different sample variations are obtained. Subsequently, all samples was characterized by using XRD, while the highest carbon graphite content was characterized by using FTIR and SEM-EDX. The results of XRD characterization shows amorphous phase pattern with carbon graphite 2H as highest element while calcium, phosphorus, and pottasium as the impurities. The highest graphite content is obtained from sample with heating temperature at 51°C while the smallest graphite content is obtained at 71°C with percentage of 90.93% and 84.06%, respectively. The FTIR characterization confirms that two functional groups are formed including aromatic (C=C) at wavenumber of 1560.93 cm−1 and epoxy (C-O) at wavenumber of 1228.54 cm−1. The SEM image reveals that granular particles were formed with different size distribution while EDX analysis confirms high amount of carbon content with 96.49%. [ABSTRACT FROM AUTHOR]

The characterization of plant powder extract during the processing is presented in this research. Under industrial scale spray drier conditions; the effect of drying on the C.caudatus powder extract was studied. The physicochemical attributes to the powder including the flavonoid constituents, particle size, size distribution, colour measurement and its bioactive compounds were discussed. C.caudatus retained significant amount of quercitrin 0.72%w/w and quercetin content (0.36%w/w) respectively. The particles size achieved in this study was 277 µm by volume mean diameter (D4,3) and 203 µm by surface mean diameter (D3,2) respectively. The results indicate that spray drying method is suitable to produce extract with good physical and chemical quality. The result of this study may promote the potential of C.caudatus powder extract as food ingredient and nutraceutical product. [ABSTRACT FROM AUTHOR]

We report here the process of oxidation and its role in the synthesis of Ti2AlC in various conditions of the synthesis process. The initial reactants were either mixed in a mortar-pestle or mechanically milled, kept as a powder or isostatically pressed into pellets, sintered at 1000-1100°C either in ambient condition or in argon atmosphere or with vacuum held fixed or with dynamic vacuum or sealed under vacuum in a quartz glass tube. It was observed that the sintered products were TiO2 and Al2O3 only in all the cases except for the milled, pelletized and sintered in dynamic vacuum and in quartz tube-vacuum sealed cases. In the case of the samples annealed under static vacuum conditions, in powder form (for both milled and hand-mixed samples) showed small traces of nitride formation. Sintering under dynamic vacuum and in sealed quartz tube modifies the pressure of oxygen around the sample such that the matrix of Al2O3 creates a protective cocoon around the intermediary phases of Ti-Al-C, preventing their further oxidation and thereby leading to the formation of Ti2AlC. [ABSTRACT FROM AUTHOR]

321 steel powders were obtained by melt spraying from the ingot and plasma spraying of the wire, which were tested in additive technologies. Detailed structural studies of powders and additive samples were carried out, as well as measuring of mechanical properties. Comparison of steels samples manufactured from powders produced by various metallurgical methods were carried out. [ABSTRACT FROM AUTHOR]

The paper presents the results of experiments aiming at the development of materials and methods for shaping them for the needs of medical applications. Selective Laser Melting (SLM) of prepared powder mixtures (CP-Ti+3,5% of Mo) makes it possible to prepare functional parts with good mechanical properties via in-situ alloying process. Application of 10 times smaller Mo powder in the mixture with CP-Ti allowed to building of biocompatible parts with increased tensile strength by appr. 10-15% compared to the CP-Ti. Achieved material, from the Ti-3,5%Mo powders mixture, with a tensile strength of above 850MPa, may be an alternative to the commonly used Ti6Al4V alloy. Mechanical mixing of powders and SLM in-situ alloying proved to be alternative for preparation (atomization) of alloy powders for the needs of laser-based additive manufacturing processes. [ABSTRACT FROM AUTHOR]

Corrosion inhibitor has a function as the best way to afford protection to metals damage from corrosive medium. Nowadays corrosion inhibitors made based on natural recources (organic) to be more extensively used for industry purpose due to organic inhibitors are cheaper and called as green inhibitor due to proper recources to its surroundings than inorganic inhibitor. One or other alternative inhibitor based from natural recources is soursop leaves (Annona muricata L.). The benefit compound from soursop leaves used for corrosion inhibitor is alkaloid. This study aims to find out the soursop leaves powder inhibition capability at various particle sizes and the duration of immersion on iron plates in sodium chloride (NaCl) solution medium. The particle sizes of soursop leaves powder used in this study are 50/70 mesh, 70/100 mesh, 100/120 mesh, and 120/140 mesh with certain concentration of 2%. The immersion duration in 50 mL of 3% NaCl is varied at 2 days, 4 days, 6 days and 8 days. The parameters determined in this study are the corrosion rate and iron efficiency, which are conducted by the weight reduction method. The results obtained showing that the corrosion inhibitor of soursop leaves powder has ability to decrease the corrosion rate iron plate in NaCl medium. The best results in this study are obtained with a particle size of 120/140 mesh and after 8 days of immersion. The corrosion rate in this condition is 1.23 mpy and the corrosion inhibition efficiency is 51.70%. [ABSTRACT FROM AUTHOR]

Linear Low-Density Polyethylene (LLDPE) has good mechanical properties, translucent, flexible, waterproof, and easily processed into thin sheets. Therefore, LLDPE is suitable for mulch film production. However, besides having advantages, LLDPE-based mulch film has some disadvantages when applied in the field. LLDPE mulch is easily degraded due to sunlight ultraviolet (UV) radiation and is also difficult to decompose in the soil after it's used. The addition of lignin or coconut coir powder that has high lignin content was intended to improve LLDPE mulch properties regarding UV resistance properties and biodegradability. In this preliminary study, the mechanical and thermal properties ofLLDPE mulch by adding lignin and coconut coir powder with high lignin content were studied. The mulch was in form of a thin sheet plastic composite. LLDPE and lignin or coconut coir powder were compounded with rheomixer at a temperature of 120 °C, and a rotor speed of 80 rpm for 6 minutes. The proportion of lignin or coconut coir powder was 1%, 5%, and 9% of the total weight. Thereafter, the compound produced was hot-pressed into a thin sheet of plastic. The plastic sheet's mechanical properties were characterized using Universal Testing Machine and the thermal properties were analyzed using Differential Scanning Calorimeter. The addition of 9% coconut coir powder resulted in the highest modulus of elasticity and tensile strength values, which were 0.202 GPa and 16.91 MPa, respectively. Thermal analysis of LLDPE with the addition of lignin showed melting points that were close to LLDPE or lignin. The addition oflignin slightly changed the LLDPE melting point. The crystallization temperature (Tc) of LLl (lignin 1%), LLS (lignin 5%), and LL9 (lignin 9%) were not much different; 106.22°C, 106.22°C, and 105.66°C, respectively. The addition of 5% lignin or coir powder increases the crystallinity of LLDE film compared to the addition of 1% lignin or coir powder. However, the addition of9% lignin or 9% coir powder decreases the mulch film's crystallinity, due to higher lignin or coir powder content loading into LLDPE which prevents the crystallization of LLDPE. Based on thermogravimetry analysis, LLDPE+lignin 9% film is more thermally stable than LLDPE+coir 9% film. Moreover, the temperature processing of coir powder while blended with thermoplastic should be below 209°C to avoid thermal degradation of the coir powder. [ABSTRACT FROM AUTHOR]

The main theoretical prerequisites for the thermodynamic analysis of the process of grinding rocks are given. The structural-energetic relationships between the regularities of plastic deformation with energy characteristics that occur during the crushing of mineral substances are described. The evaluation of the grind ability of rocks in a ball mill under different grinding modes was made. Rational operating modes of the mill have been determined to ensure the required degree of grinding, which makes it possible to significantly reduce the energy consumption of the grinding process. [ABSTRACT FROM AUTHOR]

This article provides a scientific and practical justification for the expediency of using dried persimmon powders in the production of bakery products. The results of a study of the influence of additives on the properties of the main biopolymers of wheat flour, the quality of dough and finished products, and the food safety of the objects of study are presented. The expediency of using the studied powders in the production of rich Uzbek flatbreads has been proved, which leads to an improvement in the technological properties of semi-finished products, a reduction in their preparation time and the production of finished products with indicators that are important for consumers. [ABSTRACT FROM AUTHOR]

Electrical Discharge Machining (EDM) is widely utilized to fabricate different conductive materials counting those that are difficult to be machined with intricate profiles. Powder Mixed Electro-Discharge Machining (PMEDM) could be a later advancement to upgrade the capabilities of conventional EDM. In this operation, appropriate materials in Nano-powder shape are mixed within the dielectric fluid. An equal percentage of Nano-graphite powder have been mixed with the transformer oil and used as the dielectric media in this work. The aim of this study is to analysis the outcome of some process factors such as nano-powder concentration, current, pulse on time, and pulse off time of machining High-speed steel on the material removal rate (MRR), and surface roughness (Ra). It is found that added nano-graphite mixing powder to the dielectric fluid enhanced the MRR and Ra at various conditions. Maximum MRR was (38.784 mm3/min) obtained at nano-powder concentration of (10 g/l), current (30 A), pulse on time (70 µs), and pulse off time (55 µs), and better Ra was (3.612 µm) at (10 g/l, 10 A, 50 µs, and 55 µs). Results indicated that the proposed method exhibited a material removal rate and surface finish 3.013, 1.729 times higher than that of without adding nano-powder. The proposed method showed an increase in MRR by 66.81% and surface roughness is improved by 42.18%. [ABSTRACT FROM AUTHOR]

The effect of magnesium oxide content on the physical and mechanical properties of the composites with crushed sulfur was studied.2hr), where magnesium oxide powder was added in volume proportions (20,15,10,5,0)%, then the powder was ground by a home-made grinding device using balls of diameter (10 mm). Then the powder was compressed by (5 TON) pressure for one minute, then the sintering process of the models was carried out at a degree (6000C) for an hour and a half and that the increase in the MgO content before sintering led to an increase in the hardness from (82.13-117.73)Hv, while after sintering the hardness values were increasing from (87.63 - 122.19)Hv, the reinforcement ratio at 15%MgO showed the best hardness values. And the compressive strength before sintering increased from (28.11-42.29)MPa while after sintering it increased from MPa (33.71-44.58) and also the best values of compressive strength were obtained at 15% MgO The powder reinforcement leads to an increase in compressive strength to some extent, which is 15% MgO The wear test showed that increasing the MgO content before and after sintering leads to a decrease in the wear rate, as it is noted that the wear rate decreases before sintering with the increase in the magnesium oxide content, as it decreased from(1.55×10−6−1.65×10−5), while after sintering at 600 oC degree a decrease was observed. The wear rate ranged from2.19×10−7−4.25×10−6, where the best reinforcement ratio was for the magnesium oxide content at 15% MgO. [ABSTRACT FROM AUTHOR]

Electrical discharge coating (EDC) is a well-known technique among researchers for modification of metallic surfaces. This process is capable of producing a hard coating layer, biocompatible and high corrosion resistance at low operating cost. Unfortunately, the process develops unfavourable microcracks and porosity on the substrate surface attributed by heat generation. Thus, in this study, the effect of several parameters to the microdefects' formation was investigated through an experimental work based on fractional factorial design. This work was conducted on a nickel-titanium (NiTi) shape memory alloy by varying the EDC parameters, namely; polarity, discharge duration, peak current, pulse interval, gap voltage and additive Ti nano powder concentration in deionized water (DI water). ANOVA results exhibited that the discharge duration has dominated the microcracks and porosity fraction on the substrate surface due to the impact of high intensity of discharge energy. Although, the Ti nano powder mixed in the DI water had capability to reduce the microcracks formation, the porosity fraction during at high gap voltage setting was elevated with the Ti nano powder mixed. [ABSTRACT FROM AUTHOR]

Fetal Bovine Serum (FBS), which offers nutrients for cell growth, has been the most widely used serum in proliferation studies. It does, however, necessitate screening because it contains unidentified elements, as well as viruses and prions, which pose a risk of infection. Apis mellifera royal jelly has the potential to replace FBS as a serum. In this study, a comparison of the effectiveness of three royal jelly treatments on lymphocyte cell proliferation will be performed: untreated royal jelly, soluble royal jelly, and hydrolyzed royal jelly, which is then freeze-dyed to generate a powdered product. Lymphocyte cells were cultured with various concentrations (2.5%, 5%, 7.5%, and 10%) and three different treatments of royal jelly. The results of these various concentrations were continued for up to 48 hours with continuous checking every 24 hours measured by the Microtetrazolium (MTT) assay. According to the results, lymphocyte cells cultured with the addition of a 2.5% concentration of untreated royal jelly Apis mellifera had significant differences, with the percent cell viability of 77.15% at 24 hours and 58.44% at 48 hours. This value was higher than that of soluble royal jelly (64.13% and 38.52%) and royal jelly hydrolyzate (71.08% and 54.59%) with the addition of the same concentration. [ABSTRACT FROM AUTHOR]

MgB2 has the potential for superconducting wire applications because it has a simple crystal structure, high current density and coherence length, and grain boundaries transparency. So, it is expected to be used as a substitute for Nb3Sn and NbTi superconducting materials in magnetic resonance imaging (MRI) applications in the health sector. The chemical doping technique to achieve the superconductivity phenomenon is considered the most effective in increasing the Jc and Hc of the MgB2 superconductor. The chemical doping technique in the form of nano carbon and graphite using the powder in sealed tube (PIST) method was carried out in this study by inserting Mg, B, and various carbon powders into a 316 stainless steel tube with the desired composition, then both ends of the tube were pressed to isolate the sample from oxidation during the sintering process. Four (4) variations of carbon doping composition in this study, i.e., variation carbon doping as much as 5 and 10 wt.%, then variation graphite as much as 5 and 10 wt.%. The effect of adding graphite and carbon nanoparticles is known through X-ray diffraction (XRD) analysis to determine the phase change and crystal structure, then observations using scanning electron microscope (SEM) to determine particle size, homogeneity, and porosity of each sample. The effect of adding of graphite and carbon nanoparticles is known through XRD analysis and observations using SEM. Analysis of the XRD results showed that the peaks formed were MgB2, and the other phases were Mg, B, C, and MgO, with an average crystal size of 38.1159, 33.5453, 28.0377, 17.0373, and 25.2136 nm. While the results of SEM observations indicate that the grains have started to become homogeneous, there is still porosity and agglomeration in some samples with an average grain size of 2.4913, 2.51926, 2.5163, 2.53742, and 2.5126 µm. [ABSTRACT FROM AUTHOR]

Hydroxyapatite is a well-known biocompatible material which is widely used as bone graft and bone cement. In this study, hydroxyapatite was extracted from red snapper bone waste using mechanochemical methods. This study aims to optimize the milling time of the hydroxyapatite extraction process from red snapper bone waste. The extraction process begins by grinding the bone into a fine powder and then soaking it in chloroform while sonicating and drying. Then NaOH was added to the powder in a cylindrical jar and after that the mixture was ground with various grinding times. The milling products were then characterized by thermal gravimetric analysis (TGA), Fourier transform infra-red (FTIR) and X-ray diffraction (XRD). The results showed that there was a decrease in mass loss at each additional milling time with the largest loss at 30 minutes of milling and the smallest loss at 480 minutes of milling. TGA analysis also revealed a decrease in mass with each increase in milling time when the sample was heated from 30°C to 25°C. FTIR analysis showed that the red snapper bone powder contained CH and CN organic groups from samples with milling times of 30 and 60 minutes, while the typical hydroxyapatite functional groups, namely OH−, PO43-, and CO32-, were present in all samples. The presence of the CO32- group was also confirmed by XRD where type B hydroxyapatite appeared as the secondary phase. XRD analysis also informed that the crystal size of all samples of Red Snapper fish bones was in the range of 8.61 – 21.51 nm with a degree of crystallinity of 28.53 to 48.43% and the Ca/P molar ratio was from 1.69 – 1.93. Therefore, based on material decomposition, crystal structure, crystal size and Ca/P molar ratio, it can be concluded that the optimum milling time in this process is about 120 minutes. [ABSTRACT FROM AUTHOR]

Niobium and tantalum oxides are commonly produced through acid digestion of columbite-tantalite (coltan) minerals in hydrofluoric acid followed by solvent extraction, precipitation, and calcination processes. Efforts to improve the purity of the niobium and tantalum oxides have been made by several researchers by implementing alkali fusion followed by water and acid leaching prior to hydrofluoric acid digestion to remove major impurities in coltan such as Al, Sn, Ti, Fe, and Mn. In the present work, synthesis of niobium oxide was performed by combined process between alkali fusion and hydrofluoric acid digestion and characteristic of the synthesized powder was compared with the one obtained by direct acid digestion. The coltan samples were received from a mine area in Nigeria which represent those of high Nb grade (Sample A) and low Nb grade (Sample B). Series of alkali fusion experiments, water leaching and sulfuric acid leaching and their combinations with the HF digestion were carried out to study the effect of the combined process on the purity of Nb2O5 product as well as co-precipitation of Ta in Nb precipitate. The combined process significantly enhanced the grade of Nb2O5 from 81.64% (obtained by direct HF digestion) to 90%. SEM analysis reveals that the niobium oxide powder consists of individual crystals that has a rectangular spike morphology. [ABSTRACT FROM AUTHOR]

In Indonesia, the use of monazite has been carried out for the rare earth processing industry by PT. Timah (Persero) Tbk with raw material in the form of tin mining waste. The pilot plant produces rare earth metal products in the form of hydroxides, such as lanthanum hydroxide La(OH)3, with a price range of US$ 230 per kg. Application of La(OH)3 includes water treatment, specialty glass, catalyst, optical coating, gas-exhaust convector, hydrogen storage material, superconductor, and dielectric material. This research was intended to specifically ball-mill lanthanum hydroxide (La(OH)3) with hydrogen gas followed by sintering and to characterize the product materials. The expected yield of this synthesis was material for the superconducting application. The sintering temperature was pre-determined based on a differential scanning calorimeter (DSC) test, which was 550°C for 1 hour. The product characterization included x-ray diffraction (XRD), particle size analysis (PSA), and scanning electron microscopy (SEM). Lanthanum di-hydride (LaH2) and lanthanum oxide (La2O3) were obtained as the products of this ball-milling, with the final compositions of 91.1 wt.% and 8.9 wt.%, respectively. The average particle size of the LaH2 and La2O3 powder mixture was 190.3 nm, downsized from 323.7 nm of La(OH)3 through the ball-milling process. SEM observation for the ball-milling product before sintering indicated the presence of particle aggregations. The increase in La2O3 content after sintering induced a higher crystallite strain of 2.0±0.1% compared to that after ball-milling. [ABSTRACT FROM AUTHOR]

The demand for affordable solar cells has encouraged the development of thin-film solar cell (TFSC) technology, which employs low-cost, readily-available, and non-toxic photovoltaic (PV) materials like Cu2ZnSnS4 (CZTS). Since CZTS is a quaternary semiconductor compound, the growth and synthesis of a single-phase CZTS are challenging due to the formation of secondary phases like ZnS and Cu2SnS3 (CTS), which affect the material's PV properties. Several studies have investigated the possibility of using ternary semiconductor compounds like CTS as an alternative PV material. This research aims to synthesize CTS compound powder using a practical method and to analyze CTS's properties and phase formation mechanism. CTS was synthesized in a solid-state reaction using copper (Cu), sulfur (S), and tin (Sn) elemental powders with various precursor compositions, including stoichiometric, S-rich, Sn-rich, and Cu-poor compositions. The experiment begins with mixing Cu, Sn, and S powders in stoichiometric composition using mortar-pestle and rotary mixing for three hours at 500 rpm, followed by annealing at various temperatures to determine the optimal synthesis parameter by investigating the CTS formation mechanism during the annealing. Then, CTS with other compositions was synthesized at optimal annealing temperature to examine the effect of the precursor composition on the purity and crystallinity of CTS material. The synthesized CTS was characterized based on thermal analysis, X-ray powder diffraction, and UV-VIS diffuse reflectance spectroscopy results. The result showed that CTS crystallization commenced at 340°C due to the reaction between Cu2-xS, S, and SnS. The optimal annealing temperature ranges between 340–420°C and 507–600°C. CTS with a Cu-poor composition in the precursor has better crystallinity and fewer secondary phases, resulting in a higher quality CTS. Diffuse reflectance spectroscopy reveals that the band gap of CTS powder is 1.67 eV, showing that the synthesized CTS is appropriate for a solar cell material. [ABSTRACT FROM AUTHOR]