Form Of Fine Powder Research Articles

A Review on Literary Aspect of “Kanta Lauha”

Rasoushadhis(Mineral and metallic drugs) plays an important role in Ayurvedic therapeutics because of their unique qualities such as quick action, minimum dose and tastelessness. Rasayana(Rejuvenation) and Yogavahi (Catalytic activity) are characteristics of a properly made herbo-mineral preparation, which is also nontoxic, readily absorbable, adaptable and assimilable in the body. Bhasmas are unique Ayurvedic metallic/mineral preparation, treated with herbal juice or decoction to form organometallic complexes, and are widely recommended for treatment of a variety of chronic ailments. The incinerated iron preparations of Ayurveda are known as Lauha Bhasma(Incenerated iron). In Samhitha period Ayas(Iron) was used in the form of fine powder. Kanta Lauhais considered as best variety among Lauhas for Lauha Bhasma compared with Teekshna and MundaLauha.Kanta Lauha is chemically Fe3O4 (magnetite) as per API. Pure magnetite contains 72.4% of Iron, but since this metal never occurs alone, the metal content of real ores is lower. So, an attempt has been made in this article to gather all the possible information regarding KantaLauha explained in Rasashastra classical textbooks.

Nikiel i jego związki. Metoda oznaczania w powietrzu na stanowiskach pracy

Nickel due to its physicochemical properties is used to produce high strength, corrosion resistant, temperature resi-stant, high resistance and acid resistant alloys. Nickel in the form of fine powder can induce an allergic response when in contact with the skin, carcinogenic properties have been proven with long-term exposure to nickel dust. According to the proposed directive of the European Parliament No. 2020/0262, a value of maximum allowable concentration (MAC) in a workplace air in Poland for the inhalable fraction should be at 0.05 mg/m3 and for the respirable fraction at 0.01 mg/m3 (2020/0262/COD). The aim of this study was to develop a method for determining nickel in the range of 1/10 ÷ 2 of the MAC. The method is based on gathering nickel aerosol and its compounds contained in the air on a filter, filter mineralization in nitric acid(V) and hydrochloric acid at elevated temperature then determination of nickel content in the sample using atomic absorption spectrometry (AAS) with flame atomization. The method for the determination of nickel is presented in the form of an analytical procedure, which is included in the appendix. This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

Nikiel i jego związki. Metoda oznaczania w powietrzu na stanowiskach pracy

Nickel due to its physicochemical properties is used to produce high strength, corrosion resistant, temperature resistant, high resistance and acid resistant alloys. Nickel in the form of fine powder can induce an allergic response when in contact with the skin, carcinogenic properties have been proven with long-term exposure to nickel dust. According to the proposed directive of the European Parliament No. 2020/0262, a value of maximum allowable concentration (MAC) in a workplace air in Poland for the inhalable fraction should be at 0.05 mg/m3 and for the respirable fraction at 0.01 mg/m3 (2020/0262/COD). The aim of this study was to develop a method for determining nickel in the range of 1/10 ÷ 2 of the MAC. The method is based on gathering nickel aerosol and its compounds contained in the air on a filter, filter mineralization in nitric acid(V) and hydrochloric acid at elevated temperature then determination of nickel content in the sample using atomic absorption spectrometry (AAS) with flame atomization. The method for the determination of nickel is presented in the form of an analytical procedure, which is included in the appendix. This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

Macroscopic MOF Architectures: Effective Strategies for Practical Application in Water Treatment.

Metal-organic frameworks (MOFs) have potential applications in removing pollutants such as heavy metals, oils, and toxins from water. However, due to the intrinsic fragility of MOFs and their fine powder form, there are still technical barriers to their practical application such as blockage of pipes, difficulty in recovery, and potential environmental toxicity. Therefore, attention has focused on approaches to convert nanocrystalline MOFs into macroscopic materials to overcome these limitations. Recently, strategies for shaping MOFs into beads (0D), nanofibers (1D), membranes (2D), and gels/sponges (3D) with macrostructures are developed including direct mixing, in situ growth, or deposition of MOFs with polymers, cotton, foams or other porous substrates. In this review, successful strategies for the fabrication of macroscopic materials from MOFs and their applications in removing pollutants from water including adsorption, separation, and advanced oxidation processes, are discussed. The relationship between the macroscopic performance and the microstructure of materials, and how the range of 0D to 3D macroscopic materials can be used for water treatment are also outlined.

Fine powder of lipid microparticles – spray drying process development and optimization

ObjectivesPerformed studies were focused on developing spray drying technique for aqueous dispersion of solid lipid microparticles (SLM) by selecting appropriate process parameters and assessing their impact on the process and properties of the obtained dry SLM powders. SignificanceSpray drying allows to obtain SLM in a dry powder form when the liquid form does not present sufficient long-term stability (e.g. due to degradation of the active substance or aggregation of particles) or when the dosage form is to be used in a fine powder form. MethodsIn the first stage of research the experiments were designed to optimize process parameters during spray drying of the placebo SLM dispersions prepared with two lipids: Compritol or stearic acid. The inlet temperature and feed rate were process parameters selected for monitoring. As response values, yield and quality attributes of the final product, namely particle size, moisture content and powder flowability were chosen. The process parameters optimized in the first step were then used to dry the SLM with model active substances: cyclosporine and spironolactone. ResultsThe use of 3D surface charts, developed on the basis of the results of the conducted experiments, allowed for the selection of optimal process conditions for obtaining final product with desired properties and satisfying yield. For SLM with Compritol these were: inlet temperature 90 °C and feed rate 2.4 ml/min; whereas for SLM with stearic acid 80 °C and 3 ml/min were optimal, respectively. Process parameters optimized for placebo formulations were found to be equally suitable for drying drug-loaded SLM. ConclusionsThe spray drying was found to be an effective method of obtaining dry powders from aqueous SLM dispersions. The lipid forming the SLM matrix should be considered the most important factor on which the process parameters depend. The most appropriate drying conditions selected during drying placebo formulations proved to be equally effective when SLM with the same composition and with model active substance were subjected to drying.

Hierarchical ZIF-decorated nanoflower-covered 3-dimensional foam for enhanced catalytic reduction of nitrogen-containing contaminants

Metal Organic Frameworks (MOFs) represent a promising class of metallic catalysts for reduction of nitrogen-containing contaminants (NCCs), such as 4-nitrophenol (4-NP). Nevertheless, most researches involving MOFs for 4-NP reduction employ noble metals in the form of fine powders, making these powdered noble metal-based MOFs impractical and inconvenient for realistic applications. Thus, it would be critical to develop non-noble-metal MOFs which can be incorporated into macroscale and porous supports for convenient applications. Herein, the present study proposes to develop a composite material which combines advantageous features of macroscale/porous supports, and nanoscale functionality of MOFs. In particular, copper foam (CF) is selected as a macroscale porous medium, which is covered by nanoflower-structured CoO to increase surfaces for growing a cobaltic MOF, ZIF-67. The resultant composite comprises of CF covered by CoO nanoflowers decorated with ZIF-67 to form a hierarchical 3D-structured catalyst, enabling this ZIF-67@Cu foam (ZIF@CF) a promising catalyst for reducing 4-NP, and other NCCs. Thus, ZIF@CF can readily reduce 4-NP to 4-AP with a significantly lower Ea of 20 kJ/mol than reported values. ZIF@CF could be reused over 10 cycles and remain highly effective for 4-NP reduction. ZIF@CF also efficiently reduces other NCCs, such as 2-nitrophenol, 3-nitrophenol, methylene blue, and methyl orange. ZIF@CF can be adopted as catalytic filters to enable filtration-type reduction of NCCs by passing NCC solutions through ZIF@CF to promptly and conveniently reduce NCCs. The versatile and advantageous catalytic activity of ZIF@CF validates that ZIF@CF is a promising and practical heterogeneous catalyst for reductive treatments of NCCs.

Effects of High Plasticity and Expansive Clay Stabilization with Lime on UCS Testing in Several Conditions

Clay is a cohesive and very soft soil if it has high water content. To overcome this problem, clay soils with high plasticity need to be stabilized. The method of soil stabilization with lime is an alternative effort to improve soil that does not meet the standards. Lime reacts with groundwater so that it changes the property of the soil, reducing the stickiness and softness of the soil. Lime also functions to solidify (stabilize) and stabilize (stabilize) soil in the form of fine powder consisting of metals and inorganic mineral composition. This study aims to determine the effect of clay soils when carried out stabilization by using a limestone additive which varies in levels of mixture. The results showed that lime effective for the stabilization high plasticity and expansive clay by increasing the compressive strength value of UCS with lime content of 10% under curing conditions in 28 days and unsoaked by 319%, the liquid limit value reduced by 6% and the plastic limit value increased by 46%.

Complex Alumina‐Ferrous Coagulant for Effective Wastewater Purification from Hydrogen Sulfide

The article provides an overview of studies on the causes of the formation of hydrogen sulfide in anaerobic conditions of urban sewage systems and methods for neutralizing toxic reagent sulfur‐containing compounds. It is noted that the presence of sulfur compounds and organic components in sewage flow leads to the formation and release of hydrogen sulfide into the atmosphere of settlements. Three main categories of methods for purifying sewage wastewater from hydrogen sulfide are presented. In this work, a complex alumina‐ferrous coagulant has been developed from Kazakh raw materials. Based on natural ferruginous diatomite and middlings of sintered alumina, a complex alumina‐ferrous coagulant has been synthesized, which is effective in purifying wastewater from hydrogen sulfide, accelerating the processes of sedimentation and clarification of sewage slurries. Experimental results also show that with the supply of increased amounts of coagulant, oil and oil films disappear from the surface of the cylinder, an almost complete purification of effluents from hydrogen sulfide compounds occurs, and the color of the liquid part is greatly reduced. In addition, the advantage of the developed reagent is that it is presented in the form of fine powder and can be easily dosed and added to a canalization pump station to interact with diluted hydrogen sulfide and be transported to sewage fields. Compared to other proposed methods in previous works, the reagent is suitable to be used directly in sewage systems such as sewage waters treatment plants and collectors to prevent hydrogen sulfide emission into the air atmosphere of populated areas, as well as at city sewage water treatment stations after air tanks and before secondary clarifiers to obtain better purified water suitable for watering agricultural plants.

Mechanical and morphological properties of Citrus Maxima waste powder filled Low-Density polyethylene composites

Until recently, synthetic filler materials have been the preferred choice for reinforcement of polymers to improve its toughness. However, natural filler and fiber materials are emerging as suitable alternatives to synthetic materials for reinforcing polymers due to their environmental friendliness, high abundance, renewability, and cost-effectiveness. In the present study, the waste portion of the fruit Citrus Maxima (CM) commonly known as Pomelo, in the form of fine powder was blended with Low-Density Polyethylene (LDPE) for making the composite using the injection molding method. The peel of CM consists of a foamy portion which was separated, thoroughly dried at 50–70 °C and ground into a fine powder and was used as an eco-friendly particulate filler with the LDPE matrix in different proportions (0, 5, 10, 15, and 20 wt%) in treated and untreated form. The filler was treated with 2 wt% of Silane coupling agent. XRD and FTIR confirmed the cellulosic behavior of the CM foam. The effect of filler content on the mechanical properties of the untreated and treated composites was investigated. The morphology and the microstructure of the composites were observed by XRD, FTIR, and SEM. The surface treatment showed significant improvement in the tensile strength, % elongation and impact strength for the treated composite at higher loading of filler. The mechanical behaviour of the composites led to the successful utilization of CM waste portion for making an eco-friendly reinforcing additive to form LDPE composites.

Physical and Chemical Fundamentals and Technical Solutions for Recovery of Non-ferrous and Rare Metals from Industrial Wastes


 
 
 The increasing demand for zinc and a range of zinc-related metals (for example: lead; indium; tin; cadmium; and copper) in the Russian Federation cannot be satisfied by the existing production plants due to the lack of raw materials. At the same time, ferrous and non-ferrous metallurgy and the chemical industry have accumulated hundreds of millions of tons of zinc wastes (falling into the hazard categories 2 to 4), the processing of which could not only make up the raw material base, but also improve the environmental situation. In the world, over 85% of ferrous dust is recycled using the Waelz process. The Waeltz process is used for distilling separation of elements under reducing conditions. In this study, a block diagram for production of the following elements from industrial wastes is proposed: zinc, cadmium and indium in form of massive metals; zinc and indium in the form of fine powders; and clinker as a raw material for cement production. The technical and scientific details of this new process have been patented in the Russian Federation and abroad. For the first time, the following operations have been implemented with the use of large-sized Waelz kilns: vapour-oxidized Waeltz treatment of polymetallic wastes; recycling of heat from gases and solid products with generation of process fumes; and implementation of alternative flux (dolomite) and alternative fuel (petroleum coke).
 Keywords: Waelz process, industrial wastes, heat recycling, vapour-oxidized Waelz processing
 
 

Mechanical Performance Studies on Composites Using Polyethylene Terephthalate Char Derived from Polyethylene Terephthalate Waste Bottle–Reinforced Polyester Composites

Abstract In the modern world, the disposal of wastes and its reusage is always a challenging task. Many researchers have been working toward the reusage of wastes. This research article reports on one such method to reuse the pet bottles that are used worldwide. The pet bottles were crushed, then they underwent a pyrolysis process, and the polyethylene terephthalate (PET) char extracted from it was used as reinforcement for composite production. Waste bottles are collected and chopped into small pieces and packed in a closed container. This container is kept in the furnace and maintained at a temperature of 300°C. After 3 h, the plastic char is taken from the container and ball milled for about 5 h in order to obtain the PET char in fine powder form. The extraction of PET char followed by the mechanical property studies on PET char derived from waste PET bottles has been carried out to know its effectiveness as a primary reinforcement in the polyester matrix and will be discussed in detail. The PET char is reinforced with polyester composites with varying weight percentages of 5, 10, and 15 %. The addition of PET char in the polyester matrix drastically increases the tensile strength and flexural strength by 24 and 20 % compared with pure polyester matrix. From the results, it was noted that 10 % wt. PET char-reinforced composites revealed better mechanical properties, which indicates its potentiality to be used for composite manufacturing.

Synthesis and Properties of Yttrium Ammonium Carbonate

An yttrium ammonium carbonate with the composition NH4Y(CO3)2 ∙ H2O has been prepared by reacting hydrated yttrium oxide with ammonium carbonate at 80°C. The synthesis process has been shown to proceed through crystallization of two intermediate phases: yttrium ammonium hydroxycarbonates differing in composition. The synthesized compounds have been characterized by X-ray diffraction, IR spectroscopy, differential scanning calorimetry, thermogravimetry, and chemical analysis. The first X-ray diffraction characteristics of NH4Y(CO3)2 ∙ H2O and crystallographic data for its unit cell have been presented. Thermal decomposition of the yttrium ammonium carbonate has been shown to yield cubic yttrium oxide in the form of fine powder.

Properties of cement-based composites with carbon mineral admixture

In the construction industry, aggregates, in the form of fine powder up to gravel, play a significant role as a stabilizing and filling materials for many applications. With increasing demands on quarrying of this valuable commodity, its natural resources have become to be depleted. This work outlines the potential application of waste carbon-based mineral admixture as a partial replacement of natural silica aggregate in the production of cement-based composites. In addition, the influence of used waste material on hydration products formation in cement pastes was investigated. On hardened concretes stored 28 days under water, material properties were characterized by measuring flexural and compressive strengths. Cement pastes were subjected to X-ray diffraction analysis and scanning electron microscopy observations. Obtained results revealed specific behaviour of an incorporated material allowing its addition in a limited amount. Increased content of ettringite was detected in composites with the highest amount of added carbon-based mineral.

Partial replacement of cement with polyethylene terephthalate fiber to study its effect on various properties of concrete

Plastics being very light, high quality, easy to mould, less thickness and a minimal effort is required for its use as a basic material in different industries. The most widely and extensively used form of plastic is the Polyethylene Terephthalate (PET) which is used as a crude material for soft drinks, soda bottles, and many other materials of the daily use. After the usage of the PET bottles, these are very difficult to be disposed off and are mostly dumped or burnt resulting in the degradation of environment. One of the best methods is to use the PET as replacement in concrete. In this paper, the use of PET in the form of fine powder as the replacement of Fine aggregates with the addition of Marble dust is investigated. The impact of using crushed PET as fine aggregate replacement in concrete and its effect on the strength of concrete has been studied. Different percentages of PET 0%, 4%, 8%, 12%, and 16% as fine aggregate replacement with the addition of 2% marble dust as an additive was used. Particle size distribution test and specific gravity test was also conducted on PET aggregates. The fresh and hardened concrete tests such as Workability test, compression test, flexural test and split tensile test were also carried out on cube, beams and cylinders. The test results showed that the strength of the specimens increased at 8% of PET replacement with 2% marble additives compared to the normal specimens at different curing ages. The Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) were also carried out to determine the nature and shape of PET molecules.

Influence of E-waste on properties of bituminous mixes

In the past decade, the use of E-Waste is increased due to the increase in usage of electronic components to a greater extent. The large quantity of damaged Electronic printed circuit boards (E-PCB) is discarded into the environment without proper recycling treatment in many places. The reuse of E-PCB waste in the construction industry is the most common practice nowadays. The present study focused on partial replacement of bitumen with E-PCB waste to a certain percentage in the form of fine powder and non-metallic chips. The bitumen was replaced by the various percentage of E-PCB waste as a fine powder to attain the optimum value. The optimum value is used as constant to replace the coarse aggregate of bituminous mixes with E-PCB non-metallic chips. This study investigates the properties of bitumen (includes penetration value, ductility, softening point, flash & fire point, and industrial viscosity) and Marshall stability of various bituminous mixes. The replacement of bitumen with E-waste resulting in the improvement of Marshall stability and flow value of bitumen.

Effect of Powder-Mixed Dielectric on EDM Process Performance

Electrical Discharge Machining (EDM) is extensively used to manufacture different conductive materials, including difficult to machine materials with intricate profiles. Powder Mixed Electro-Discharge Machining (PMEDM) is a modern innovation in promoting the capabilities of conventional EDM. In this process, suitable materials in fine powder form are mixed in the dielectric fluid. An equal percentage of graphite and silicon carbide powders have been mixed together with the transformer oil and used as the dielectric media in this work. The aim of this study is to investigate the effect of some process parameters such as peak current, pulse-on time, and powder concentration of machining High-speed steel (HSS)/(M2) on the material removal rate (MRR), tool wear rate (TWR) and the surface roughness (Ra). Experiments have been designed and analyzed using Response Surface Methodology (RSM) approach by adopting a face-centered central composite design (FCCD). It is found that added graphite-silicon carbide mixing powder to the dielectric fluid enhanced the MRR and Ra as well as reduced the TWR at various conditions. Maximum MRR was (0.492 g/min) obtained at a peak current of (24 A), pulse on (100 µs), and powder concentration (10 g/l), minimum TWR was (0.00126 g/min) at (10 A, 100 µs, and 10 g/l), and better Ra was (3.51 µm) at (10 A, 50 µs, and 10 g/l).

Characterization and calcination behavior of a low-grade manganese ore

Characterization and calcination behavior of a low-grade manganese ore, as a part of Mn ferroalloys production, was studied by XRF, ex-situ XRD, in-situ XRD, and SEM-EDS techniques. Calcination experiments were carried out at and up to 900 °C (1173 K) in air and argon atmospheres. The samples were in particles and powder forms. The results indicated that both quartz and calcite phases in the ore exhibit a bimodal spatial distribution; as relatively large regions and finely distributed in the Mn- and Fe-containing phases. By Rietveld analysis of the in-situ XRD data, the reactions occurring upon heating during the calcination process were deduced. Thermal decomposition and reactive diffusion were found to be the dominant mechanisms in the calcination process. The results demonstrated that there were some phases forming and vanishing during the calcination process in air, such as calcium ferrites, calcium oxide, and bixbyite. While Fe-containing bixbyite was thermally decomposed to hausmannite at low temperatures, magnetite was the product at higher temperatures. However, magnetite was also formed through the diffusion between hematite and hausmannite phases. Reactive diffusion was much more prevalent in fine ore powder form than particles. Formation of complex phases such as (di-)calcium ferrite and bustamite was the result of the reactive diffusion mechanism. Although thermal decomposition of Mn and Fe oxides was not influenced by particle size, the final product of calcination was highly affected by the particle size, as a result of reactive diffusion.

Evaluating effectiveness of dust by-product treatment with scrubbers to mitigate explosion risk in ZrO2 atomic layer deposition process

In processes of manufacturing semiconductors, reactive by-products (as a form of fine powder, i.e., dust) are deposited in pipes installed on post processing and exhaust systems, potentially involving a considerable explosion risk. In this study, the effectiveness of scrubber methods (e.g., dry scrubber and burn-wet scrubber) to mitigate the risk was evaluated. To this end, three by-products generated from a ZrO2 atomic layer deposition (ALD) process were collected from semiconductor manufacturers, which were treated with different methods (i.e., no treatment, treatment using dry scrubber, and treatment using burn-wet scrubber), and their characteristics were analyzed and compared. Particle size measurements of the by-products proved that the burn-wet scrubber treatment less decreased their particle size than the dry scrubber treatment. The burn-wet scrubber treatment made the by-product thermally stable, confirmed by thermogravimetric analysis. Fourier-transform infrared spectroscopy of the by-products before and after the scrubber treatments showed that burn-wet scrubbing of the by-product decreases surface functionalities that play a role in explosion. Dust explosion testing proved that robustness of explosion of the untreated by-product is about 7 times higher than the by-product treated with the burn-wet scrubber. Based on the results of this study, it would be suggested that burn-wet scrubber is a useful treatment method to decrease the explosion risks caused by dust by-products generated from ALD in semiconductor manufacturing processes.

Synthesis and study of trivalent cerium activated Ca2Pb3(PO4)3Cl noval blue emitting phosphor for solid state lighting

The PL emission and excitation spectrum of prepared Ca2Pb3(PO4)3Cl:Ce3+ phosphor explained in which excitation at wavelength of 331 nm and it prepared by combustion synthesis method for the emission spectrum exhibits a well defined asymmetric band with maximum at 443 nm emitting a blue light give isolated blue emission at 443 nm for 10 mol %, which has higher PL emission concentrations. The samples were characterized by XRD, SEM, PL and CIE color co-ordinates techniques with relation of emission intensity w.r.to. concentrations of rare earth ion. This process enables quick and energy-efficient generation of well-crystallized particles in fine powder form within a little action. The emission spectra are clearly from the same observable site. No another emission band was observed in emission spectrum indicating that trivalent cerium ion occupies one category of sites in the host material.

Synthesis of potential bio-adsorbent from Indian Neem leaves (Azadirachta indica) and its optimization for malachite green dye removal from industrial wastes using response surface methodology: kinetics, isotherms and thermodynamic studies

The response surface methodology has been extended to study the adsorption of malachite green dye (MG) on Indian Neem leaf powder (NLP), Azadirachta indica. The study was experimented by varying the solution concentration from 10 to 100 mg/l. The removal percentage of MG was determined by spectrophotometer at wavelength of 618 nm. Design Expert 11.0 was used as a tool to study the optimal conditions of MG adsorption (applying 2-factorial interaction model of central composite design) and evaluation of interaction effects of different operating parameters including pH, time, solute concentration, temperature and adsorbent dosage. Numerical optimization helped to identify the optimal conditions for achieving the targeted dye removal of 95.493% when the pH, time, solute concentration, temperature and adsorbent amount were set at the range of 6.868, 36.4 min, 27.899 mg/l, 308.477 K, and 4.3475 g/l respectively. The experimental results indicate that the maximum adsorption capacity of NLP depends on various operating parameter like, pH, dye concentration, particle size of adsorbents and it’s activation. It was noted that adsorption capacity of the NLP increases from 33.33 to 66.72 mg/g when it was activated with dilute HCl. The higher correlation coefficient value (R2) of Langmuir isotherm 0.996 and lower p value (0.01203) indicate the fitness of the response surface 2FI model developed. Kinetic studies displayed the suitability of pseudo second order reaction for this adsorption process. The thermodynamic study show that the sorption process is exothermic and spontaneous in nature. It was observed that the adsorbent NLP in the form of fine powder are very effective for the removal of MG from its aqueous solution. The satisfactory values of regression coefficients at different temperature, and fittings of adsorption isotherms indicate that Indian NLP is a promising adsorbent for treatment of textile dyes.