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It is important to predict the environment around the breathing human because inhalation of virus (avian influenza, human influenza, SARS) is recently severe worldwide problem. And air pollution caused by diesel emission particle (DEP) and asbestos attracts a great deal of attention, and their restrictions are becoming tight. In the present study, three-dimensional numerical simulation is carried out to predict the gas-particulate two-phase flows around breathing human and how suspended particulate matter (SPM, diameter ∼ 1 μm) reaches the human nose in inhalation and exhalation using Lagrange approach for particle motion and k-e model for flows. Our research is a unique dealing with micro particle motions. Such small particles have great ability to affect our health in some case. In the calculation, the authors find out the smaller breathing angle and the closer distance between human nose and pollutant region are effective in the inhalation of SPM.

This paper presents the effect of hot isostatic pressure post-treatment on tin powder particle under elevated temperature in order to obtain the spherical particle shape. The tin powder particle obtained from the gas atomization as used as a precursor. The powder was placed in the liquid olive oil within the Teflon-lined autoclave, which was then subjected to the hot isostatic pressure post-treatment at five type temperature for specified time. The as-treated powder was rinsed, dried, and observed morphologically using high resolution digital microscope. It is found that the ratio of spherical particle shape is increased by 2.4 - 3 times, relative to the untreated powder particle, which can be achieved after 210 minutes post-treatment at temperature of 90% of its melting point. The density of the post-treated powder is increased by 1.05 - 1.15 times, and the porosity is increased by 5.7 – 8.0 times. These results offer another possible method to obtain spherical and enhance density metal powder particle for specific purposes.

Magnetite (Fe3O4) nanoparticles has been successfully synthesized using the co-precipitation method with various pHs. The magnetites were derived from natural ironstone Kalimantan, Indonesia. The synthesis was carried out with 4 variations of precipitation pHs, i.e., 8.00; 9.06; 10.00; and 11.00. X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), High-Resolution Transmission Electron Microscopy (HRTEM), and Particle Size Analyzer (PSA) were utilized to examined the crystal structure, micro and nanostructures, and particles size distribution, respectively. The XRD results revealed that the magnetite is the dominant phase of all samples and the single phase of magnetite can be achieved with the precipitation pH > 9.06. Moreover, the particle sizes of the magnetite nanoparticles are 11, 10 and 7 nm for 9.06, 10.00, and 11.00 precipitation pH, respectively. The SEM and HRTEM images show that the particle size of ironstone and magnetite precipitates is in micro and nanoscales. The PSA results show that the particle size distribution of the magnetite nanoparticles tend to decrease with the increasing level of pH. Meanwhile, the average particle size tend to decrease with the increasing of precipitation pH,+ from 153 nm (8.00), 315 nm (9.06), 190 nm (10.00), and 153 nm (11.00). HRTEM images show that particles of Fe3O4 is spherical in shape and tend to agglomerate.

Experimental studies give a ground to state that condition of oxide film surface of aluminum particle after its fracture depends on thermo-mechanical loading rate. The article is devoted to the model of particle surface condition after its fracture, which is developed by the authors. Influence of loading rate on particle ignition dynamics is shown. It is determined that the model allows to describe regularities of aluminum particle ignition in condensed systems.

The application of Zirconium Silicate (ZrSiO2) as refractory coating material can improve the smoothness of casting surface and overcome die soldering. The cost is quite expensive, causing the need for alternative materials to reduce production costs. Alumina (Al2O3) is one of alternative material because of its high melting temperature and free of iron content. This study aims to determine proper concentration variation, distribution of alumina particles as a partial substitution of the refractory fillers in the casting layer, and drying treatment of coating samples. The variation of concentration used in alumina is 16 wt.%, 18 wt.%, and 20 wt.%. Particle distribution used is filler material that is with and without milling. Coating samples optimized by drying at room temperature and 100 °C. The characterization used was Particle Size Analyzer (PSA), viscosity value, and Differential Thermal Analysis (DTA) to test the heat resistance of the coating. The surface scanned by Scanning Electron Microscope (SEM). The results of 16 wt.% concentration alumina in a higher viscosity value facilitates better coating deposition, a wider distribution of alumina particles are resulting a variety of particle sizes that support the quality of the casting coating due to grain interlocking and passing gases out of metal castings, and drying coating samples at temperatures 100 °C produces morphological densities. The result of adding alumina is considered comparable to the refractory coating made from zircon silicate.

It is reported the synthesis of CaCO3 particle by a simple and rapid procedure with different drying methods. FTIR, XRD, SEM, and PSA techniques have been used to characterize the precipitated products. Precursor for the synthesis is natrium carbonate and calcium nitrate tetrahydrate in deionized water. Reactions were conducted at a temperature of 27° C for reaction times at 60 minutes and stirring speed at 800 rpm. CaCO3 synthesized with drying using desiccator obtained a spherical and porous surface CaCO3 particle and an average diameter size of 1589.4 nm. CaCO3 synthesized with drying using freeze-drying obtained an irregular shape and average diameter size of 2669.7 nm. Different drying methods can produce different morphology dan sizes of CaCO3 on micro-scale.

Copper Cadmium Oxide and Copper Manganese Oxide nanocomposites were synthesized through chemical co-precipitation route. The nanocomposites annealed at 800°C were used for further structural as well as optical studies. Scherrer equation was used to calculate the average particle sizes of the nanocomposites. The optical characterizations of the metal oxide nanocomposites were carried out by UV-Visible spectroscopy analysis. Using the absorption spectra, the optical bandgap of the nanocomposites were calculated.

The silica (SiO2) particle was synthesized using the precipitation method of sodium silicate (Na2SiO3) precursor by additional HCl as precipitant. In this paper, the precipitant was mixed directly to the solution of sodium silicate (Na2SiO3) in contrast to the conventional dropwise technique which prevented a high production rate. The dropwise of HCl was carried out to know the effect of pH at two different temperature 25 °C (T20) and 80 °C (T80) on the obtained particles. It was obtained that the optimized process was at temperature 25 C. Subsequently, the mixing technique of HCl (conventional dropwise and direct mixing) were investigated at temperature 25 °C. The result showed that direct mixing technique resulted in high production rate with acceptable size and dispersion of silica nanoparticles. It is also highlighted that the proposed direct mixing technique of HCl received a simple and faster-precipitated process in large scale production. Therefore, it is proposed that for the scale-up production of silica nanoparticle by precipitation of the sodium silicate (Na2SiO3) precursor with additional of HCl may be prepared by direct mixing method at pH 7 in temperature 25°C.

Ethyl p-methoxycinnamate (EPMC) is a marker of kencur (Kaempferia galanga L.) which shows anti-inflammatory activity but is has poor water solubility. The aim of this study is to improve the solubility of EPMC by using cocrystallization method and citric acid as coformer for particle formulation. EPMC-citric acid particles have been successfully prepared by concentration variation of molar ratio EPMC-citric acid 1:1; 1:2; 1:3. EPMC-citric acid particles characterized by means of Fourier Transform Infrared Spectroscopy (FTIR) and orbital shaker for water solubility study. The results showed that citric acid concentration variation did not obtain any different in the increasing solubility of EPMC in the cocrystal system. The solubility of EPMC – citric acid increased by 44.19% compared to untreated EPMC. The intermolecular hydrogen bond that form supramolecules between EPMC and citric acid and the presence of water-soluble citric acid as coformer responsible for increasing water solubility of EPMC. It was concluded that cocrystallization method utilizing citric acid as coformer for EPMC preparation successfully formed hydrogen bonds and enhanced solubility of EPMC.

Ag nanoparticles were synthesized on the surface of SnO2 and ZnO by photoreduction from an aqueous solution of silver nitrate and borohydride reduction, respectively. The influence of synthesis conditions on particle sizes was analyzed by atomic force microscopy. The study of gas-sensitive properties of Ag-ZnO composites showed that their response to isopropyl alcohol vapors enhanced compared to pure zinc oxide.

For a sustainable environment and minimizing pollution, dates palm trunk residues were used as natural strengthening (reinforcing) particles to improve the mechanical properties of silicone rubber as the matrix material, The particles of the palm trunks were used in three sizes and three concentration concentrations of 1% 3% and 5%, where the reinforced with the particles increases the tensile strength from 1MPa to be about 2 MPa, and the hardness value raised from about 32 MPa to be about 39 MPa, in addition to that the reinforcing particle of dates palm trunk exhibit high resistant to moisture absorption. The results of the search clarify that the composite samples reinforced at 1% and 75 particle size gives the best results for tensile and hardness tests in addition to moisture absorption test.

Most of the metallic materials are now replaced by polymeric materials in some engineering applications. Because of low thickness, easy handling and reduced costs plastics find wide territory in loading applications areas. Polymer Composite material with ABS matrix and PTFE particle filler has been extensively gainful to apply lightweight development materials which have high wear resistance quality and low coefficient of friction. Addition of Polytetrafluroethylene (PTFE) particles with Acrylonitrile butadiene styrene (ABS) by 10-20 weight% are known to upgrade the tribological properties of ABS copolymer. The addition of PTFE particles upgrade, interfacial bonding between polymer matrix and fillers are increased. Composite specimens are fabricated effectively by molten condition utilizing Injection molding procedure. The pins on disc wear test were conducted using prepared composites specimens according to ASTM standard. The impact of added PTFE particles enhanced better self-lubrication properties. In this work presented that, to enhance the tribological properties of ABS copolymer by including PTFE particle by composite process. The tribological properties like mass loss, specific wear rate and coefficient of friction were inspected.

In this study Urea Formaldehyde (UF) were resins prepared, modified and non-modified to formation composites reinforced with waste sawdust particle, with consideration the urea purity as a main composite factors and formalin life span. these are directly contributing factors that influence on composites properties such as Thermal coefficient Resistivity and specific gravity. Plastic wood was prepared by used (Quercus, pear, Tectona, Fagus, Jew, Spruce, MDF) sawdust powder as reinforce phase with particle size less than (

Coal is the cheapest and reliable source for power generation, which has the potential to reduce the dependency on natural gas, particularly for Bangladesh, where the natural gas reserve is very limited. Despite numerous studies on gasification from different parts of the world, there has not been a research study on gasification characteristics of Bangladeshi Barapukurian coal (BBC) under state of the art entrained flow condition. Thus, this study aims to investigate the gasification characteristics of Barapukurian bituminous coal using a high-temperature electrically heated entrained flow gasifier under atmospheric pressure.The effect of the partial pressure of the gasification reagent (CO2) on carbon conversion and gas yield was tested by varying the volume percentage of CO2 in N2 between the temperatures of 1000-1400°C. Furthermore, the influence of particle size on carbon conversion and product gases was also examined using industrially relevant particle sizes: 90-106 µm and 250-300 µm. The results show that increasing the temperature and feed CO2 concentrations increase the carbon conversion, though the temperature is found to be the dominant factor. A maximum carbon conversion of 92 % was achieved using ultimate operating conditions of 1400°C and 40% CO2 for particles size: 90-106 µm, while the conversion was only 65% for particle size: 250-300 µm under identical operating conditions. Overall, the yield of CO was increased while the yield of H2 was decreased with increasing temperatures and CO2 concentrations. The maximum yield of CO and H2 was determined to be 0.93 and 0.14 L/g coal respectively using particle size: 90-106 µm, which is 0.88 and 0.12 L/g coal using particle size: 250-300 µm at a temperature of 1200°C under 10% CO2. The main pollutants measured were HCN, NH3 and H2S in the ppm range. The results of this study will provide a baseline data for the industrial scale entrained flow gasification of BBC under CO2 atmosphere.Coal is the cheapest and reliable source for power generation, which has the potential to reduce the dependency on natural gas, particularly for Bangladesh, where the natural gas reserve is very limited. Despite numerous studies on gasification from different parts of the world, there has not been a research study on gasification characteristics of Bangladeshi Barapukurian coal (BBC) under state of the art entrained flow condition. Thus, this study aims to investigate the gasification characteristics of Barapukurian bituminous coal using a high-temperature electrically heated entrained flow gasifier under atmospheric pressure.The effect of the partial pressure of the gasification reagent (CO2) on carbon conversion and gas yield was tested by varying the volume percentage of CO2 in N2 between the temperatures of 1000-1400°C. Furthermore, the influence of particle size on carbon conversion and product gases was also examined using industrially relevant particle sizes: 90-106 µm and 250-300 µm. The results s...

One of the major agricultural wastes alongside rice husk, bagasse, corn hub etc. is coconut shell. These agricultural wastes can be found in abundance in South Asian countries like India. Throughout the recent studies it has be found that these agricultural wastes can be effectively recycled in engineering and other scientific applications. In the present study, the authors have tried to introduce coconut shell as a reinforcing particle into the aluminium matrix to prepare a metal matrix composite. The composites were prepared using stir cast technique which has a provision of bottom pouring. The fabricated composite specimens were tested for their mechanical properties such as density, hardness, tensile strength. The results on the samples showed a considerable improvement in the properties.

This paper explores trends of air surface Carbon monoxide (CO) in relation with Particle Materials (PM10), Nitrogen dioxide (NO2), Air Quality (AQ) and meteorological parameters in Bucharest test area in Romania during March 2016 - February 2017. The major sources of air pollution with high CO contribution in urban areas are vehicular emissions, wildfires and biomass burnings for residential heating. The frequency distribution patterns of each target compound were evaluated for entire period using the relevant daily mean values. The lower summer values of CO concentrations are attributed to photochemistry, and more efficient dispersion, while winter enhanced values of CO concentrations can be attributed to the extensive use of central heating, decreased photochemistry, shallower boundary layer and poor dispersion due to stationary conditions. Positive Pearson Coefficients of CO concentrations have been recorded for Particle Materials PM10, Nitrogen dioxide NO2, as well as with air humidity and pressure meteorological parameters.

In this research, investigate the effect of weight fraction (1%, 2%, 3%, 4%) industrial waste (silica gel particles) as fillers with 3% carbon fiber in unsaturated polyester resins on some properties such as flexural strength, flexural modulus, compressive strength, and thermal conductivity. Specimens composite was conducted by using the hand lay-up method and tested according to ASTM standards. The average particle size of the silica gel was 136.4 µm. Analyzed of the mechanical and physical properties that examined using SPSS with Tukey test and One Way ANOVA to know effect weight fraction of (carbon fiber/silica gel particle) on those properties, where statistical significance was set at P ≤ 0.05. From results, it is observed that the addition of silica gel particles up to 4% with 3% carbon fiber as strengthening materials to unsaturated polyester resins, leads to increase values the flexural strength, flexural modulus, compressive strength (293.00 ± 4.000 MPa), (5.4300 ± .04560 GPa), (124.67 ± 5.033 MPa) respectively, while the values of thermal conductivity decrease with addition 4% silica gel to (.0300 ± .02000 W/m.K°) compare with specimen unsaturated polyester (.3367 ±.03215 W/m.K°). The results of (SPSS) showed that the values (P) calculated from One Way ANOVA for flexural strength, flexural modulus, compressive strength, and thermal conductivity were (0.02, 0.001, 0.0001 and 0.04) respectively, less than (0.05) this indicates that the filler material has a clear effect on those properties that have been examined.In this research, investigate the effect of weight fraction (1%, 2%, 3%, 4%) industrial waste (silica gel particles) as fillers with 3% carbon fiber in unsaturated polyester resins on some properties such as flexural strength, flexural modulus, compressive strength, and thermal conductivity. Specimens composite was conducted by using the hand lay-up method and tested according to ASTM standards. The average particle size of the silica gel was 136.4 µm. Analyzed of the mechanical and physical properties that examined using SPSS with Tukey test and One Way ANOVA to know effect weight fraction of (carbon fiber/silica gel particle) on those properties, where statistical significance was set at P ≤ 0.05. From results, it is observed that the addition of silica gel particles up to 4% with 3% carbon fiber as strengthening materials to unsaturated polyester resins, leads to increase values the flexural strength, flexural modulus, compressive strength (293.00 ± 4.000 MPa), (5.4300 ± .04560 GPa), (124.67 ± 5.033 MP...

Silica in the nanoscale has interesting properties compared to its bulk counterpart that leads to a different range of applications. This is due to its low toxicity, high physical and chemical stability, large surface area to volume ratio and direct surface chemistry that allows to be combined or functionalized with a variety of functional species or molecules. Most researches used metal alkoxides or agricultural materials for the source of silica but very few researches attempted at preparing nano-silica powder from silica sand via the chemical method. In this research, the nano-silica powder is prepared via sol-precipitation method and its subsequent characterization. The materials used for this project were silica sand, sodium hydroxide, hydrochloric acid and distilled water. Surface morphology using Field Emission Scanning Electron Microscope (FESEM) of the silica sand was found to be irregular in terms of its size and shape. The average particle size of the silica sand determined by FESEM was found to be around 230 µm. The nano-silica has quartz SiO2 structures as demonstrated from XRD analysis. The synthesized nano-silica particle have a huge reduction in terms of size between 58 nm to 290 nm using FESEM. It was also found that the nano-silica particles were very agglomerated and had a spherical or globular particle shape. Hence, the silica sand can be an alternative precursor for synthesis of nano-silica particle by the sol-precipitation method instead of using other chemical precursor.

Polyelectrolytes have remained one of the most attractive subjects of scientific research in recent decades owing to their great importance in advanced technologies and molecular biology. In this study, particle polyelectrolyte complexes (PPECs) were formed by mixing cationic chitosan (Ch) and anionic alginate using the jet mixing technique. Within certain limits, the size of the formed PPECs could be controlled and they are in the nano-sized range. The aim was to investigate the effect of the assembly pH and ionic strength on the PPECs size. The influence of Ch molecular weight on the PPECs size was also studied. Dynamic light scattering was used for PPECs size estimation. It was found that the pH and ionic strength affect the chitosan/alginate interaction force. Hence, PPECs with desired size could be formed by varying the assembly conditions.

Air quality in urban areas located in complex terrain is intimately related to meteorological phenomena that occur in such regions. Major meteorological factors that determine the concentrations of air pollutants are the wind field and the turbulent diffusion. In this study, we investigate the characteristics of the sea breeze and their influence on aerosol particles, ozone and CO2 concentrations around Ahtopol, a small town located at the southern Bulgarian Black Sea coast. Field experiment, performed from 24 to 29 August 2017, comprised measurements of meteorological parameters, aerosol particle number with 6-channel Aerosol Particle counters, atmospheric optical depth (AOD) and total ozone content (TOC) with Microtops II solar photometer and ozonometer, correspondingly. The statistical analysis revealed that onset and cessation periods of the sea breeze were from 9:00 to 10:00 and from 19:00 to 21:00 LST, respectively. The average maximum strength of the sea breeze was 3-4 ms−1. Studying the variation of aerosol particles and CO2, it is concluded that the sea breeze onset is associate with decrease of small particles number, and decrease of CO2 concentration.Air quality in urban areas located in complex terrain is intimately related to meteorological phenomena that occur in such regions. Major meteorological factors that determine the concentrations of air pollutants are the wind field and the turbulent diffusion. In this study, we investigate the characteristics of the sea breeze and their influence on aerosol particles, ozone and CO2 concentrations around Ahtopol, a small town located at the southern Bulgarian Black Sea coast. Field experiment, performed from 24 to 29 August 2017, comprised measurements of meteorological parameters, aerosol particle number with 6-channel Aerosol Particle counters, atmospheric optical depth (AOD) and total ozone content (TOC) with Microtops II solar photometer and ozonometer, correspondingly. The statistical analysis revealed that onset and cessation periods of the sea breeze were from 9:00 to 10:00 and from 19:00 to 21:00 LST, respectively. The average maximum strength of the sea breeze was 3-4 ms−1. Studying the variation ...

The main objective of the SOLPART H2020 project is to develop, at a pilot scale (30-50 kW), a high temperature (800-1000°C) 24h/day solar process suitable for particle treatment in energy intensive non-metallic minerals’ industries. Calcium carbonate decomposition (Calcination reaction: CaCO3= CaO + CO2) is the most representative and most endothermal reaction in this type of application of solar process heat for industry. This paper presents the context, the particle to be treated, the reaction thermodynamics and kinetics, the mass and energy balances and the solar reactor technology currently under development.

In this study a crude extract of Centella asiatica and ginger extract as bioactive compound on formulated nanoemulsion using sonicator at frequency 20 kHz, 500 Watt with 7-18 kHz ultrasonic wave frequency with emulsification time 10-60 minutes. The formulated nanoemulsion used oil-in-water emulsion type (O/W) weight ratio of 20:80 (% b/w) and Hydrophilic-Lypophilic Balance (HLB) values of the O/W emulsion system in the range of 10.0-16.5 to obtain emulsions on a nanometer scale. Surfactants used in this study were tween 85 and triethanol amine. The results showed that the optimum frequency at 7 kHz with nanoemulsion particle size of 222.9 nm with emulsification time 30 minutes. The effect of surfactant tween 85 on nanoemulsion showed that the higher concentration of surfactant tween 85, the smaller size of the nanoemulsion particle was. The concentration of tween 85 surfactant in the amoun of 8.0% weight was the optimum concentration with 99.2 ± 45.2 nm nanoemulsion particle size on HLB 13.93. The concentration of surfactant tween 85 (8.5 wt%) with HLB 14.50, the nanoemulsion particle size rose again to 126.1 ± 4.5 nm, while the optimum concentration of surfactant triethanol amine at 1.2 wt%, with the particle size of nanoemulsion 82.6 ± 46.5 nm.

The CdS-based nanocomposite was synthesized by the sol-gel method at room temperature using water alkaline solution of sodium silicates, or liquid glass, for the first time. An average diameter of nanoparticles varies from 3 to 10 nm depending on synthesis conditions. It was demonstrated using the methods of spectrophotometry and luminescence in the UV, visible and NIR optical ranges that optical properties of the nanocomposite significantly depend on the presence of water molecules near the particle surface. Replacing of water matrix to silica oxide based matrix has led increasing the luminescence intensity and changing of recombination processes participating in the emission.

Erosion-corrosion is common engineering problem causes a deterioration failure in many industries including oil and gas production, drilling, process and transportation of minerals including oil sands. This paper highlights fine particles erosion studies on two materials of High-Density Polyethylene (HDPE) and carbon steel under wet sand impact conditions frequently encountered on pipeline surfaces of hydrocarbon production industry. In this study, we perform an experiment to study the influence of fine particle on erosion characteristics of High-Density Polyethylene (HDPE) and carbon steel. In the experimental setup, a closed loop wet erosion technique was adopted, in which the flow speed of a carrier medium was set to be 0.09 m/s and the configuration of the rectangular plate were specified for three impact angles of 30°, 90° and -30° with fine particle sizes of 60 µm. Scanning Electron Microscopic (SEM), hardness test and roughness test of the eroded specimens were conducted to understand characterization of the target surface. SEM and hardness analysis revealed that for carbon steel, the surface of sample angled at 90° encountered significant erosions under impact conditions. It was noticed that hardness of HDPE was not affected at 90° and it encountered less surface roughness loss compared to carbon steel.Erosion-corrosion is common engineering problem causes a deterioration failure in many industries including oil and gas production, drilling, process and transportation of minerals including oil sands. This paper highlights fine particles erosion studies on two materials of High-Density Polyethylene (HDPE) and carbon steel under wet sand impact conditions frequently encountered on pipeline surfaces of hydrocarbon production industry. In this study, we perform an experiment to study the influence of fine particle on erosion characteristics of High-Density Polyethylene (HDPE) and carbon steel. In the experimental setup, a closed loop wet erosion technique was adopted, in which the flow speed of a carrier medium was set to be 0.09 m/s and the configuration of the rectangular plate were specified for three impact angles of 30°, 90° and -30° with fine particle sizes of 60 µm. Scanning Electron Microscopic (SEM), hardness test and roughness test of the eroded specimens were conducted to understand characterizat...

The damage of bone tissue may cause malfunction of human load-bearing system. To date, hydroxyapatite (HA) is one of the most potential materials to repair bone damages and to restore the load-bearing function. It has been produced from both synthetic chemical and natural resources, including limestone. In this paper, the properties of hydroxyapatite made of CaCO3 from limestone was investigated in a function of sintering time, i.e., 2, 3 and 4 hours, and temperature, i.e., 600, 800 and 1000qC. The preparation of HA included crushing, meshing, grinding and sintering. HA powder was then characterized using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS). The hardness of compacted hydroxyapatite powder was also characterized using microVickers testing machine. SEM micrograph shows the agglomeration of particle increase in line with sintering temperature. The highest hardness was obtained for hydroxiapatite sample sintered at the highest temperature and for thelongest time, while EDS result indicates the highest ratio of calcium and phosphor was 2.33. The percentage of calcium in the observed local HA decreased as the sintering time increased. A comparison of XRD result between the commercially imported and the local HA powder produced in this study shows a similarity pattern, which indicates the potential replacement of the imported HA by our local limestone resources.

CdS is one of the most important compounds in the II-VI group of semiconductor. There are numerous applications of CdS in the form of nanoparticles and nanocrystalline. Semiconductors nanoparticles (also known as quantum dots), belong to state of matter in the transition region between molecules and solids, have attracted a great deal of attention because of their unique electrical and optical properties, compared to bulk materials. In the field of optoelectronic, nanocrystalline form utilizes mostly in the field of catalysis and fluid technology. Considering these observations, presented work had been carried out, i.e. based on the nanocrystalline material preparation. In the present work CdS nano-crystalline powder was synthesized by a simple and cost effective chemical technique to grow cadmium sulphide (CdS) nanoparticles at 200 °C with different concentrations of cadmium. The synthesis parameters were optimized. The synthesized powder was structurally characterized by X-ray diffraction and particle s...

Due to the over-harvesting of low valued wood for the production of low and medium density particle boards the forest resources are decreasing day by day and hence finding new substitutes for producing particle board is a major concern nowadays. This study attempts to fabricate and examine the structural and mechanical properties of banana pseudo-stem-based particle boards that are capable to serve as a cost effective and technologically viable substitute to the conventional wood chip. Banana pseudo-stem has been used as the raw material with commercially used urea formaldehyde resin as the binder. A systematic experimental study is carried out to examine the effects of parametric variation (particle-board density, resin concentration and thickness of the sample) on the physical and mechanical properties of the particle-boards such as tensile, compressive and maximum crushing strength, screw holding strength etc. The fabricated particle-boards exhibit excellent mechanical and physical properties. It is found that the physical properties greatly vary with thickness, density and percentage of binder used in the particle board. For a constant density of the particle board, 12 mm thick boards exhibit the maximum internal bond strength and the strength decreases with increasing thickness. Both the maximum crushing strength and screw withdrawal force are obtained at a resin concentration of 9%, while both higher and lower resin concentration give inferior results. The particle-boards fabricated in this study can have significant potential for substituting wood-based particle-boards in a range of applications.

The effect of solid solution temperature (1100 and 1200°C) on microstructure, phase composition and temperature dependence of 0.2% offset yield strength R0.2, in the temperature range of 77 to 673 K was studied for high-nitrogen austenitic Fe–19Cr–21Mn–1.5V–0.3C–0.9N (wt. %) steel. Increase in solid solution temperature provides a partial dissolution of (V, Cr)(N, C) particles and increases a concentration of carbon and nitrogen in austenite. A complex effect of solid solution hardening and particle strengthening provides strong temperature dependence of the yield strength in the steel independently on solid solution temperature. The mechanisms, responsible for the variation in the yield strength with test temperature and solution treatment, are described on the basis of the microstructural parameters of the steel.

C60-ethylanediamine adduct particle (C60P) were prepared by simply mixing of C60 and ethylenediamine (EDA) in toluene. C60P was dissolved into EDA to obtain C60P-EDA. C60P-EDA can be diluted by ethanol, 2-methoxyethanol or water. Thin films of C60P-EDA were prepared from these diluted solutions of C60P-EDA by spin-coating. Such thin-films were used as a part of organic thin-film solar cells.

The mechanical and physical properties of palm kernel shell (PKS) reinforced with high-density polyethylene (HDPE) have been investigated by using there different filler loading of 5wt.%, 10wt.% and 15wt.%. The PKS filler was prepared for two different particle sizes namely fine size (150 µm-212 µm) and coarse size (300 µm-422 µm). The HDPE/PKS composites were compounding by using twin screw extruder and turn them into pallet form. Then, pallet form of HDPE/PKS composites sample was prepared with an injection moulded machine produced dogbone shape of samples. Tensile test and flexural test has been used as the mechanical testing for this study. Based on the results of tensile strength, the fine size PKS provided better result than the coarse size PKS for the 10wt.% PKS loading. Optimum PKS loading was the sample with 10wt.% PKS loading comes with fine size PKS as the finer the size of PKS give better tensile strength.

Gene gun is a mechanical device which has been used to deliver DNA vaccine into the cells and tissues by increasing the uptake of DNA plasmid so it can generate a high immune response with less amount of DNA. Nozzle is an important part of the gene gun which used to accelerate DNA in particle form with a gas flow to reach adequate momentum to enter the epidermis of human skin and elicit immune response. We developed new designs of nozzle for gene gun to make DNA uptake more efficient in vaccination. We used Computational Fluid Dynamics (CFD) by Autodesk® Simulation 2015 to simulate static fluid pressure and velocity contour of supersonic wave and parametric distance to predict the accuracy of the new nozzle. The result showed that the nozzle could create a shockwave at the distance parametric to the object from 4 to 5 cm using fluid pressure varied between 0.8–1.2 MPa. This is indication a possibility that the DNA particle could penetrate under the mammalian skin. For the future research step, this new nozzle model could be considered for development the main component of the DNA delivery system in vaccination in vivo

The first performance test of a novel windowed solar fluidized bed reactor was carried out for a two-step water splitting cycle with ceria particles by using a 30-kWth sun-simulator. O2 and H2 were successfully produced by the reactor system. During the thermal reduction step of the two-step water splitting, a fluidized bed of ceria particles was created by passing N2 gas through the perforated bottom plate of the reactor, and about 30 kWth of high flux visible light from 19 xenon-arc lamps of the sun-simulator was directed inside the reactor through a quartz window to directly irradiate the top of the fluidized bed. The central bed temperature reached the temperature of 1400 to 1500°C in the thermal reduction step. The subsequent water decomposition or hydrolysis step was performed at the central bed temperature of 800 - 900°C. About 6 - 12 Ndm3 of hydrogen was produced by one cycle.

The rheological properties of several tens of nanofluids based on water, ethylene glycol, and engine oil with nanoparticles of various oxides and diamond is studied experimentally. Particle concentrations and their sizes were varied within quite wide range. Tested nanofluids did not contain any dispersants, while the base fluid was Newtonian liquid. It is revealed that in some cases, nanofluids are characterized by non-Newtonian rheological behavior. In the last part of the paper the effect of the nanoparticles on the properties of drilling fluids is discussed.

We have worked on the development of a particle-based numerical model of a hydrogen Radio Frequency (RF) Inductively Coupled Plasma (ICP). In the previous work, it has been shown that the model is able to simulate the E-to-H discharge mode transition, which is one of the distinct features of RF ICP. The purpose of the present study is to investigate the E-to-H discharge mode transition of the hydrogen RF ICP by our numerical model. In particular, the spatiotemporal behavior of ions, which we have not investigated in the previous work, will be presented in this paper.

In this work, ZnO nanoparticles were prepared by using ZnCl2 and NaOH as precursors using sol-gel chemical method. Synthesized ZnO was characterized by using X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM) and Topas 4.2 software for Rietveld analysis. Formation of simonkolleite, Zn5(OH)8Cl2.H2O instead of ZnO nano particles was revealed from XRD studies. Formation of hexagonal zincite structure of the ZnO samples was also confirmed by XRD studies. From Rietveld analysis, rise of crystallite size was observed with increasing NaOH concentrations. Morphology and particle size of synthesized ZnO nanoparticles showed from FESEM studies 20-50 nm sized nano particles were evident from FESEM micrographs, which was found consistent with the crystallite size measured by Rietveld analysis of XRD studies. This particle has been applied in different industrial sectors such as solar cells, UV detectors, photodiodes etc.In this work, ZnO nanoparticles were prepared by using ZnCl2 and NaOH as precursors using sol-gel chemical method. Synthesized ZnO was characterized by using X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM) and Topas 4.2 software for Rietveld analysis. Formation of simonkolleite, Zn5(OH)8Cl2.H2O instead of ZnO nano particles was revealed from XRD studies. Formation of hexagonal zincite structure of the ZnO samples was also confirmed by XRD studies. From Rietveld analysis, rise of crystallite size was observed with increasing NaOH concentrations. Morphology and particle size of synthesized ZnO nanoparticles showed from FESEM studies 20-50 nm sized nano particles were evident from FESEM micrographs, which was found consistent with the crystallite size measured by Rietveld analysis of XRD studies. This particle has been applied in different industrial sectors such as solar cells, UV detectors, photodiodes etc.

A computational method for modeling the propagation of cellular detonation waves in hydrogen–air mixtures and their interaction with clouds of inert particles was developed using the ANSYS Fluent software. Equations of the laws of conservation of mass, momentum, and energy for the solid phase were added to ANSYS Fluent using custom functions. Calculations of the suppression of cellular detonation waves by inert particles were performed. Integral dependences of the detonation wave velocity deficit were obtained for various volume fractions and particle diameters.

The process in industry, including in mining industry, would surely give negative effect such as waste polluting to the environment. Some of waste could be potentially reutilized to be a commodity with the higher economic value. Tin slag is one of them. The aim of this research was to recover the tin contained in tin slag. Before coming to the electrolysis, tin slag must be treated by dissolution. The grinded tin slag was dissolved into HCl solution to form a slurry. During dissolution, the slurry was agitated and heated, and finally filtered. The filtrate obtained was then electrolyzed. During the process of electrolysis, solid material precipitated on the used cathode. The precipitated solid was then separated and dried. The solid was then analyzed using XRD, XRF and SEM. The XRD analysis showed that the longest time of dissolution and electrolysis the highest the purity obtained in the product. The SEM analysis showed that the longest time of electrolysis the smallest tin particle obtained. Optimum time achieved in this research was 2 hours for the recovering time and 3 hours for the electrolysis time, with 9% tin recovered.

Small mass fractions (< 20%) of micron-scale aluminium particles added to a high explosive can react quickly and with sufficient exothermicity to improve metal-acceleration ability (AA) relative to an equal volume of only the base explosive. In order for the aluminium to increase AA, exothermicity must more than offset losses in gas-production and from heating and accelerating the solid particles in the flow. Furthermore, particles must react promptly to deliver this energy prior to loss in driving pressure from product expansion or acoustic decoupling from the driven material. For these reasons, many aluminized formulations exhibit slight or no increase in AA. Furthermore, AA is typically studied using the cylinder test, which specifies a fixed, heavy copper wall. In the present study the authors have used symmetric sandwiches of flyer plates of widely different thicknesses to examine how charge scaling and plate acceleration time-scales influence the enhancement in AA for different sizes of aluminium particles. Nitromethane gelled with 4% Poly(methyl methacrylate) by mass was used for the explosive. 3M K1 microballoons were added at a mass fraction of 0.5% to sensitize the mixture. Aluminium with a mean particle size of 3.5 µm or 108 µm was added at 15% total mixture mass fraction. At 15% mass fraction, an enhancement in AA was observed for both particle sizes and flyer configurations. Results indicated an onset of reaction close to the sonic plane of the detonation wave.

The effects of proton (E = 100 keV, F = 54×1015 cm–2) exposure on the reflective spectra of Al2O3 hollow particles in wavelength range from 250 to 2500 nm have been investigated. Hollow particles were obtained by deposition nanoparticles on polystyrene balls in chitosan solution with subsequent heat treatment. X-ray photoelectron spectra of the material were analyzed for the O1s peak before and after irradiation. It has been established that radiation stability of the hollow particles is higher than that of Al2O3 microparticles. This effect is caused by the low concentration of color centers in the hollow particle due to lack of material in the bulk of particles.

Silicon carbide (SiC) particles were dispersed in nanocrystalline Ni (nc-Ni) matrix and thermal grain growth was studied. Microstructural characterization revealed that while the average grain size of as prepared foils of both nc-Ni and Ni-SiC nanocomposite was found to be ∼ 60 nm, presence of SiC particles restricted thermal grain growth remarkably. While the grain size of nc-Ni annealed at 300°C was found to be 210 nm that of Ni-SiC nanocomposite was only ∼100 nm. Differential Scanning Calorimetry (DSC) results exhibited higher heat flow in case of nc-Ni as compared to the Ni-SiC nanocomposite which signifies rapid thermal grain growth in the former one. Tensile tests carried out on both the materials showed that yield strength (YS) of the nanocomposite was always higher than nc-Ni. However, the ultimate tensile strength (UTS) of the former one was lower up to 100°C which might be due to premature brittle fracture initiated along SiC particle interface. At 200°C and above both YS and UTS were found to be higher for nanocomposite due to easier plastic flow being enabled at elevated temperature.

Cold spray technology is a relatively new additive process allowing to create high quality metallic coatings, on both metallic and non-metallic substrates, without extensive heating of the powders sprayed. Upon impact with a target surface, conversion of kinetic energy to plastic deformation occurs, the solid particles deform and bond together. The actual bonding mechanism for cold spray particles is still not well understood, a high number of works has been carried out during the past two decades, several theories have been proposed to explain the adhesion/rebound mechanisms making the system ineffective for industrial applications. Therefore, the aim of this research activity is to better explain the complex adhesion/rebound phenomena into cold spray impact processes through numerical simulations; for this purpose, on the base of simplified hypothesis and results found in literature, an original 3D Finite Element Method (FEM) model of an aluminium particle impacting on an aluminium substrate was proposed. A cohesive behaviour algorithm was implemented in the particle-substrate contact regions aiming to simulate the bonding between the impacting particle and the substrate under specific working conditions. A rebound coefficient was also defined representing the particle residual energy. Different simulations were performed using a range of impact velocities and varying the interfacial cohesive strength. It was shown that at low impact velocities the rebound phenomenon is governed by the elastic energy stored in the system, meanwhile at high impact velocities, the rebound phenomenon is mainly due to the strain rate effects making the system mechanically stronger; therefore, a specific range of bonding velocities depending on substrate-particle contact area were found.

We report a fecile preparation of reduced grapheme oxide (rGO) from an old coconut shell by rapid reduction of heating at 400°C, chemical exfoliation using H2SO4 and HCl intercalating and mechanical exfoliation using ultrasonication. The produced samples consist of random stacks of nanometer-sized sheets. The dispersions prepared from H2SO4 had broader size distributions and larger particle sizes than the that from HCl. An average size of rGO in H2SO4 and HCl is respectively 23.62 nm and 570.4 nm. Furthermore, sample prepared in H2SO4 exhibited a high electronical conductivity of 1.1 × 10−3 S/m with a low energy gap of 0.11 eV.

Li-ion batteries to play even more important roles in hybrid electrical vehicles (HEVs), electrical vehicles (EVs), plug-in hybrid vehicles (PHEVs), and smart grid systems area [1-3]. However, they currently fail in meeting the demands dictated by powering of large-scale storage systems for renewable energy sources. Hence, it is necessary to develop Li-ion batteries with higher energy densities. Cathode materials to play an important role among the components of Li-ion batteries to operate at high voltage and deliver high energy and high power densities. Lithium manganese borate (LiMnBO3) powders were synthesized by a sol-gel process. The structural coordination of LiMnBO3 was investigated by FTIR analysis. From X-ray diffraction patterns, confirms the formation of the nanocrystalline pure hexagonal isotypic phase of the LiMnBO3 at 650 °C. The observed SEM micrographs of the LiMnBO3 sample showed the formation of agglomerated spherical shape particle morphology of the LiMnBO3 sample is confirmed by the SEM result. The electrical conductivity of LiMnBO3 sample was evaluated by analysing the measured impedance data and it was found to be 1.37 × 10−8 S cm−1 at room temperature. Detailed results will be presented and discussed.

Excessive foaming and extensive centrifugation process encountered by purified natural rubber latex (p-NRL) has made this latex not well accepted by the industry as an imperative starting material for latex-based products. In this study, we aim to investigate the feasibility of utilizing single anionic surfactant, sodium dodecyl sulphate (SDS) in combination with urea, a protein denaturant and underwent a single centrifugation process in acquiring p-NRL. Incubation of commercially available high ammoniated natural rubber latex (HA-NRL) with urea in the presence of SDS is known to denature proteins by causing it to unfold and centrifugation process will further facilitate the removal of the unfolded protein from the aqueous serum phase of the HA-NRL. The effect of these processing parameters on the typical latex characteristics, protein separation, nitrogen content, zeta potential (ZP), rheological behaviour, morphology and physical performances of the p-NRL was examined. With specific amount of urea, fitting results of various SDS solutions at 10% (w/w) from surface tension analysis to Langmuir equation resulted in a plateau adsorption capacity. The value was calculated to be approximately 0.0236 gSDS/ grubber, corresponding to about 0.5 phr SDS saturated on the p-NRL rubber surface. Incubation of these chemical mixtures in the HA-NRL with single centrifugation process significantly eradicates most of the proteins, with detrimental effects on the distinctive p-NRL properties. Although SDS creates synergizing effect with urea for protein denaturation process, it nevertheless did not create a destabilization phenomenon to the p-NRL as the zeta potential analysis demonstrated negatively charged values over the entire pH range. Remarkable rheological performances of the p-NRL suggested that the system is proportionately stabilized by the surfactant adsorptions, which is concurrent with the zeta potential analysis. Observing the p-NRL particles in latex state and in the dried film through Environmental Scanning Electron Microscopy (ESEM) and Field Emission Scanning Electron Microscopy (FESEM) revealed a unique particle packing arrangements. It was hypothesized that the processing parameters in producing p-NRL has a pronounced influence to both particle morphologies. The film formation of p-NRL compounded with natural-based filler was studied and compared with HA latex film in term of physical properties.

In the present paper, we reported particle size kinetic studies on the conducting polyaniline (PANI) which synthesized through a chemical oxidative polymerization technique from aniline monomer. PANI was prepared using ammonium persulfate (APS) as oxidizing agent which carried out in acidic and neutral medium at various batch temperatures of respectively 20, 30 and 50 °C. From the studies, it was noticed that the complete polymerization reaction progressed within 480 minutes duration time. The pH of the solution during reaction kinetic reached values 0.8 – to 1.2 in acidic media, while in the neutral media the pH value reached values 3.8 – 4.9. The batch temperature controlled the polymerization reaction in which the reaction progressing, which followed by the temperature rise of solution above the batch temperature before settled down to the initial temperature. An increment in the batch temperature gave highest rise in the solution temperature for the two media which cannot be more than 50 °C. The final product of polymerization reaction was PANI confirmed by Fourier Transform Infra-Red (FTIR) spectrophotometer for molecule structure identification. The averages particle size of PANI which carried out in the two different media is evidently similar in the range 30 – 40 μm and insensitive to the batch temperature. However, the particle size of PANI which obtained from the polymerization reaction at a batch temperature of 50 °C under acidic condition reached ∼53.1 μm at the tip of the propagation stage which started in the first 5 minutes. The size is obviously being the largest among the batch temperatures. Whereas, under neutral condition the particle size is much larger which reached the size 135 μm at the batch temperature of 20 °C. It is concluded that the particle size formation during the polymerization reaction being one of the important parameter to determine particle growing of polymer which indicated the reaction kinetics mechanism of synthesize polyaniline.

In the context of ejecta particle experiments created from shock-wave loading a metallic surface with machining grooves, we present a method to estimate the areal mass Ms (mg.cm–2) of the particle cloud from non-invasive PDV velocimetry diagnostic. Through the statistical properties of the time-velocity PDV spectrogram, the set of parameters most likely to have generated experimental PDV data is estimated. This approach is detailed on an experiment consisting of a 1-mm thick tin surface with 2D triangular known surface patterns (period of 60 µm and peak-to-peak amplitude of 8 µm) explosively driven by an electro-detonator with a peak breakout pressure of approximately 29 GPa at the metal-vacuum interface.

Background: Manufacture of herbal honey (mixture of honey, black seed oil, and olive oil) have a problem to produce stable mixture. The addition of synthetic emulsifier can lead the stable mixture, but it has side effect. Natural emulsifier like lecithin can replace synthetic emulsifier to mix the herbal honey. Objective: The aim of this research is to analyze the influence of adding lecithin emulsifier on the stability of a mixture of herbal honey. Methods: Stability tested herbal honey mixture with 4 kinds of ways, namely centrifugation, cycling test, viscosity test, and the test particle size. Results: Centrifugation test results in a mixture of herbal honey with lecithin below 5% w/w in oil mass not show phase separation. The addition of lecithin after a certain threshold will increase the viscosity of the mixture. The addition of 5% w/w lecithin total mass of oil into the mix with the oil concentration of 7.5% w/w gives a minimum viscosity, cp 4870. Cycling test performed at 4°C refrigerator and oven 40°C for 24 hours each 3 times. Cycling test result does not indicate the availability of crystallization or phase separation. Analysis of PSA (Particle Size Analyzer) showed that the addition of lecithin causes enlargement of the particle size. The average particle diameters of herbal honey mixture without lecithin as big as 6.3 µm while herbal honey with lecithin mixture of 1% of the total oil is at a 4.67 µm. Conclusion: From this study it can be concluded that the use of lecithin 1-5% w/w of the total mass of oil (concentration from 7.5 to 10%) can produce stable mixtures.Background: Manufacture of herbal honey (mixture of honey, black seed oil, and olive oil) have a problem to produce stable mixture. The addition of synthetic emulsifier can lead the stable mixture, but it has side effect. Natural emulsifier like lecithin can replace synthetic emulsifier to mix the herbal honey. Objective: The aim of this research is to analyze the influence of adding lecithin emulsifier on the stability of a mixture of herbal honey. Methods: Stability tested herbal honey mixture with 4 kinds of ways, namely centrifugation, cycling test, viscosity test, and the test particle size. Results: Centrifugation test results in a mixture of herbal honey with lecithin below 5% w/w in oil mass not show phase separation. The addition of lecithin after a certain threshold will increase the viscosity of the mixture. The addition of 5% w/w lecithin total mass of oil into the mix with the oil concentration of 7.5% w/w gives a minimum viscosity, cp 4870. Cycling test performed at 4°C refrigerator and oven...

Effects of the stirring time in TiO2 sol chemical on the optical transmittance of the spin-coated films over the visible-to-near-infrared region were studied. It was observed that the longer stirring time, from 12 hours to 48 hours could provide films with either observably higher or lower transmittance, depending on the solvent. In Isopropanol, or IPA, the longer stirring time of the sol chemical leaded to a lower optical transmittance. In hydrochloric acid, or HCl, the trend was reversed; the longer stirring time of the sol chemical would cause a higher optical transmittance. Effects in both solvent were more pronounced at lower wavelengths, i.e. the increasing or decreasing of the transmittance with the extended stirring time could be seen more noticeably at low wavelengths. We believed that these phenomena were caused by the change in dispersion of the TiO2 particle in the solvent over the stirring time. In HCl, which is an acid-based solvent, the particle could be better dispersed than that in IPA, resulting in a proportional relation between the stirring time and the transmittance of the spin-coated films. This assumption was supported when the transmittance of the films in IPA and HCL were compared as it could be seen that the transmittance of the former was lower. The results from this study could be used to help select an appropriate preparation time of the TiO2 sol chemicals in different solvents to obtain a spin-coated film with a required level of optical transmittance.Effects of the stirring time in TiO2 sol chemical on the optical transmittance of the spin-coated films over the visible-to-near-infrared region were studied. It was observed that the longer stirring time, from 12 hours to 48 hours could provide films with either observably higher or lower transmittance, depending on the solvent. In Isopropanol, or IPA, the longer stirring time of the sol chemical leaded to a lower optical transmittance. In hydrochloric acid, or HCl, the trend was reversed; the longer stirring time of the sol chemical would cause a higher optical transmittance. Effects in both solvent were more pronounced at lower wavelengths, i.e. the increasing or decreasing of the transmittance with the extended stirring time could be seen more noticeably at low wavelengths. We believed that these phenomena were caused by the change in dispersion of the TiO2 particle in the solvent over the stirring time. In HCl, which is an acid-based solvent, the particle could be better dispersed than that in IPA, r...