Energy Dispersive X-ray System Research Articles

Spatial and Temporal variations of Organic Chemical compounds in Ambient Air from Ahmedabad City, Gujarat, India

Organic contaminants linked to atmospheric particulate matter have been a major source of worry across the world since the last decade. The ambient air samples were collected from three sites in Ahmedabad city for spatial and temporal variation using a High-Volume Air Sampler (HVAS) to examine the morphology and elemental composition of fine and ultrafine particles by using a Scanning electron microscope (SEM) and an energy dispersive X-ray system (EDAX) from PM2.5. The Si, C, O, Cl, Na, Al, K, Ca and Mg were found to be quite abundant in the EDAX spectra. Transition elements such as Ti, Zn, Cu, S and Fe were registered, indicating the influence of industry in liberating the abundance of fine and ultrafine particles. In addition, the organic chemical compounds were screened by using GC–MS. A total of 230 organic chemicals were detected, including 187 aliphatic and 43 aromatic chemical compounds at three different locations. Results show that aliphatic and aromatic hydrocarbon compounds were found maximum in the urban area followed by industrial and rural areas.

Characterizing Drift Behavior in Type K and N Thermocouples After High Temperature Thermal Exposures

Although of the widespread use of base metal thermocouples in the industry, many previous relevant researches have shown that the accuracy and stability of thermocouples are clearly influenced by any physical or chemical changes in their thermoelements. Among the most important of these changes are the inhomogeneity, pollution, oxidation and microstructure changes of the thermoelements, all of these changes and more leads to thermocouples drift after a prolonged thermal exposure. To study how these changes affect the drift and thermoelectric properties of thermocouples, in this work we subjected the base metal thermocouples of types K and N to successive thermal exposure periods at their maximum temperatures. Scanning electron microscopy (SEM) and Energy Dispersive X-ray (EDX) systems were used to monitor the change in the crystal structure and chemical composition of the thermocouple wires after each stage of the thermal heating, and then we studied the changes in the thermoelectric properties of thermocouple wires. The results showed type N thermocouples are more stable at high temperatures (up to 1050 ͦ C), even if used for long periods (for more than 1200 hours) at those temperatures, but K type thermocouples showed a rapid drift with first exposure to high temperatures and completely failed after 600 hours due to devastating corrosion.

Effect of Eggshell Powder Using for an Extender on the Mechanical and Thermal Behaviors of Polylactic Acid Composites

In this paper, the composites between polylactic acid (PLA) and eggshell powder (ESP) from the chicken shell were prepared by melt blending method in the internal mixer and then injection molded to produce the bio-composite specimen. The effect of the ESP concentration in the composites was investigated on the mechanical and thermal behaviors. The results indicated that the tensile strength and elongation decreased with increased ESP loading. Furthermore, the impact strength was not altered for PLA filled system with 10-30% of ESP. At the 10%wt of ESP in the PLA-composites was not significantly different of the onset (Tonset) and maximum degradation temperature (Td) from neat PLA but at higher ESP loading, Tonset and Td tend to decrease, therefore ESP could be able to accelerate degradation in the composites. The cold crystallization (Tcc) showed decreasing when the ESP was incorporate about 10-30 %wt. Otherwise, the incorporation of ESP affected on the declination of crystallinity in the PLA composites. The morphology, size and elements were examined using a scanning electron microscope (SEM) coupled with an energy dispersive X-ray system (EDX). It was indicated that agglomeration of ESP in the PLA matrix.

Occurrence of aliphatic and aromatic compounds associated with atmospheric particulate matter in three cities of Gujarat, India

The organic pollutants associated with atmospheric particulate matter (PM) in the environment, especially PM2.5 (particles <2.5 μm) have become a major issue worldwide in the past decade. The ambient air samples of four different sizes of particles were collected using an active air sampler (cascade impactor) from three cities of Gujarat: Anand, Ahmedabad and Surat. To study morphology and elemental composition, Scanning electron microscope (SEM) and Energy dispersive X-ray system (EDX) were used for fine particle size <1.0 μm. Besides, organic pollutants associated with particulate matter were analyzed using Gas Chromatography-Mass Spectrometry (GC–MS). Total 54 organic chemicals including 29 aliphatic (alkanes and alkanoic acids) and 25 aromatic chemical compounds were identified qualitatively. Phthalate, the well-known plasticizer was found in the atmosphere of all three study sites. In addition, polycyclic aromatic hydrocarbons (PAHs) such as naphthalene and fluorene were quantified at high concentrations in Ahmedabad (315 ng/m3 and 509 ng/m3 respectively) followed by Surat (310 ng/m3 and 382 ng/m3) and Anand (76.1 ng/m3 and 123 ng/m3). The distribution of organic chemicals was found diverse at three locations which might be influenced by the different sources and landmass usage in each city. The presence of the carbonaceous elements in the particles indicates biomass burning emissions during the winter season which might be a source of pollutants in the studied areas.

Air Pollution with Asbestos Fibers in Some Heavy Traffic Areas of Baghdad

This research was conducted to measure the levels of asbestos fibers in the air of some dense sites of Baghdad city, which were monitored in autumn 2019. Samples collection was conducted via directing air flow to a mixed cellulose ester membrane filter mounted on an open‑faced filter holder using sniffer with a low flow sampling pump. Air samples were collected from four studied areas selected in some high traffic areas of Baghdad city, two of them were located in Karkh (Al-Bayaa and Al-Shurta tunnel) and two in Rusafa (Al-Jadriya and Al-Meshin complex), then analyzed to determine concentrations of asbestos. Measuring of levels of asbestos fibers on the filters was carried out via using scanning electron microscope SEM together with an energy dispersive X‑ray system (EDS). The results showed that the lowest level was recorded in Al-Jadriya intersection (0.0352 fiber/ml), while the maximum concentration was in Al-Bayaa (0.156 f/ml). Asbestos average concentration in the ambient air of the four studied areas was 0.0718 f/ml, which exceeded the standards of world health organization (WHO) for air which is equal to 0.0022 f/ml. This may be due to the presence of crowded traffic and the occurrence of industries near the city. Therefore, plans such as management of traffic, changing locations of industrial sites, and products substitution can be effective in minimizing the concentrations of airborne fibers.

Facile mild hydrothermal treatment for surface functionalization of carbonized sawdust

This work illustrated the preparation of highly dispersive carbonized sawdust by surface functionalization through a facile mild hydrothermal treatment with an aqueous mixture of reactants, potassium persulfate and potassium hydroxide (KPS:KOH), at 160 °C. The dispersion, morphological and purity analyses play an important role in the determination of the optimal hydrothermal process parameters. Dispersion test unveiled well dispersed modified carbonized sawdust's in polar solvent (ethanol) and no significant morphological changes according to the field emission scanning electron microscopy (FESEM) images. The intensity ratio (ID/IG) from the Raman measurement displayed an increased in the modified carbonized sawdust's ID/IG which indicated successful surface functionalization. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) spectra revealed the introduction of various functional groups onto the carbonized sawdust surface, while the increment in the oxygen and potassium elements percentage (at. %) based on the energy dispersive X-ray system (EDX) supported both FTIR and XPS findings. Carbonized sawdust treated in 1:3 M ratio of KPS:KOH mixture (0.07 M:0.21 M) for 60 min showed the best dispersion in ethanol for at least a month with high degree of functionalization and various oxygen based functional groups were attached on its surface.

Evidencing Human Occupation of a Small Island Through Ancient Glass: The Case of Ustica (Palermo, Italy)

AbstractThe subject of this study consists of 17 ancient glass fragments from the island of Ustica (Palermo, Italy) obtained from local museums. All the 17 glass fragments are stratigraphically decontextualized, as they were collected by archaeological surface surveys. Each fragment was analyzed by Electron Micro Probe Analyzer coupled with an Energy Dispersive X-Ray System (EMPA-EDS) and by Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) to obtain the composition of major, minor and trace elements. Surface analyses revealed the presence of corrosion layers in most of the glass fragments which was evident also in the chemical data. Nevertheless, reconstruction of the glassmaking processes and the approximate period of production was possible for almost all the glass fragments. Less than half of the examined fragments are attributable to recognizable typologies as unguentaria, beakers, bottles, and vases; all the other small fragments are typologically undetermined. Out of 17 fragments only one fragment is of HLLA composition possibly being produced in 17th–18th century AD, while all the others can be attributed to soda glass with different periods of production: natron glass from Roman and Early Medieval period, plant-ash glass from High or Late Medieval period with the exception of possible Byzantine glass from 6th century AD, and synthetic soda glasses typical of modern era. These data confirm the discontinuous habitation of the island from the Roman period as well as the import of glass objects to the island.

Spatio-temporal variations of asbestos fibres levels in ambient air of a densely populated and industrialized city of Iran

ABSTRACTAsbestos fibre is one of the hazardous pollutants that may present in urban air. The aim of this study was to determine the concentration of asbestos fibres in the ambient air of urban areas of Isfahan, second industrialised and densely populated city of Iran, and to evaluate their spatial-temporal variation. Sampling was carried out from eleven points covering traffic areas of the Isfahan city during cold and warm seasons (winter and summer) in 2015. Scanning Electron Microscope (SEM) coupled to an energy dispersive x-ray (EDX) system was utilised to count and identify the asbestos fibres. Spatial mapping was carried out using the inverse distance weighting (IDW) method. Seasonal geometry meansof the concentration of airborne asbestos fibres in the studied regions were 14.48 ± 5 and 9.34 ± 4.90 SEM f/L in winter and summer, respectively, which was higher than the WHO guideline (2.2 SEM f/L‏).‏There was a significant correlation between the concentration of asbestos fibres and atmospheric temperature and humidity (p < 0.05). Also, the spatial distribution maps of asbestos fibres showed that the eastern area of Isfahan was more polluted than the western areas. Heavy traffic showed major contribution in the asbestos fibre emissions. Therefore, some effective course of actions such as traffic management, industrial replacement should be taken to regulate airborne asbestos fibres emission.

Chemical characterization and source identification of particulate matter at Ballari (15.15°N, 76.93°E), Karnataka over Southern Indian region

The present study reports the chemical composition and source identification of the total suspended particulate matter in the sub-urban environment, Ballari. There were 28 particulate matter aerosol sampled between February 2017–July 2018. The surface mass concentration ranged from 103 μg m−3 to 367 μg m−3 with an average value of ~225 ± 65 μg m−3 during the study period. The morphology and elemental composition of aerosol particles were analyzed by using a scanning electron microscope (SEM) coupled with an energy dispersive X-ray system (EDX). From the EDX results aluminosilicate group (Al, Si, K, Fe, Na, Mg, Ti and Ca) contains about ~31% of the total particles, which mainly due to mineral particulate aerosol originate from crustal origin through windblown dust. Further, we also investigated the morphology and chemical composition of total mass concentration during haze (27-03-2018) and clear days (23-02-2018). The SEM pictures show the most notable deposition of spherical particles with smooth surfaces on a hazy day suggesting that the carbon aerosols on haze day were favourable to coagulation of Aitken mode particles, which is consistent with their respective aerosol subtypes captured from Cloud-Aerosol Lidar with Orthogonal Polarization (CALIPSO) satellite over the study region. Inductively coupled plasma optical emission spectrometer (ICP-OES) analysis showed the relative contribution of inorganic ions (SO42−, NO3−, Na+, Ca2+, Cl−, NH4+, K+) is higher than others on 1-05-2017 and 01-01-2018 days over the observational site. The relative contribution of non-sea salt SO42− was abundance (~35%) on both days, indicating the significant anthropogenic influence at this location. The concentration weighted trajectory (CWTs) analysis showed the major sources of particulate matter were soil particles, vehicular emissions, and mining activities surroundings the vicinity of the sampling site.

Pengaruh temperatur terhadap struktur mikro dan sifat mekanik dalam proses fussion brazing Ni-Hard 4 dengan S45C menggunakan CuZn 35 sebagai logam pengisi.

This research was conducted on white cast iron (Ni-Hard 4) and medium carbon steel (S45C) cast iron materials using a thin brass plate (CuZn 35) 0.3 mm as filler metal by heating at temperatures of 850 to 1050 0 C for 120 minutes with a pressure of 2 Mpa in the muffle furnace. The effect of temperature on the microstructure was observed using an optical microscope and scanning electron microscopy equipped with energy dispersive X-ray system (EDS) to determine the chemical composition that occurred between the three meterial layers. The thickness of the interface layer increases with increasing holding temperature. The highest shear strength (79.86 Mpa) was obtained at a temperature of 950 0 C.

Rapid and selective extraction of trace amount of Pb(II) in aqueous samples using a magnetic ion-imprinted polymer and detection by flame atomic absorption spectrometry

A magnetic Pb(II) ion-imprinted polymer was synthesized using magnetic Fe3O4@SiO2 nanospheres as supporter, n-benzoyl-n-phenyl hydroxylamine as ligand, 4-vinyl pyridine as monomer, ethylene glycol dimethacrylate as crosslinker and 2,2′-azobis(isobutyronitrile) as the initiator. The template was removed from the polymer using 4 mL of HCl (2 mol L-1). The chemical structure, morphology-particle size, elemental analysis, thermal behavior and magnetic properties of the sorbent were evaluated using Fourier-transform infrared spectroscopy, scanning electron microscopy &amp; ImageJ software - Energy dispersive X-ray system, thermal gravimetric analysis and vibrating sample magnetometry. Various parameters such as pH, equilibrium extraction time, temperature and the eluent were optimized. The results showed the sorbent adsorption capacity was 92.3 mg g-1 in pH 6.0 media, equilibrium time of 7 min at 40 °C. Calibration linearity was 2-150 µg L-1 with detection limit of 0.3 µg L-1. The prepared sorbent had high selectivity and was successfully applied to the removing of lead in real samples.

Synthesis and characterization of some metals complexes with new heterocyclic azo dye ligand 2-[2- - (5- Nitro thiazolyl) azo]-4- methyl -5- nitro phenol and their biological activities

A series of Cu(II), Fe(III), Pb(II), Mn(II) metals complexes have been synthesized with the new thiazole azo dye containing tridentate [N.N.O] donor ligand 2-[2− -(5-nitro thiazolyl) azo]-4-methyl-5-nitro phenol (5-NTAMNP) derived from 2-amino-5-nitrothiazole and 3-methyl-4-nitrophenol by the diazotization operation and the adizonium chloride salt solution of 2-amino-5-nitrothiazole reacting with 3-methyl-4-nitrophenol as a coupling compound in alkaline alcoholic solution. The structures of synthesized novel ligand was identified and confirmed via resorting to various spectroscopic techniques which included, 1H NMR, Mass spectrum, UV–visible, Fourier-transform infrared (FTIR), X-Rays diffraction (XRD), the surface nature and morphology and size average and elemental composition of individual ligand particles were examined using a field emission scanning electron microscope (FESEM) coupled with an energy dispersive X-ray system (EDX), in addition to above the physical properties of ligand have been studied via check its melting point and the purity of the ligand also was checked by TLC in presence of a certain solvent system. As for the consistency positions available in (5-NTAMNP) and the manner of its association with these metallic ions it’s likely that the pattern of complexity as a tridentate chelating agent with the formation of a coordination number for all metallic ions found equal to six and have Octahedral shape for all metallic ion. The optimal condition for complexation have been studied, the prepared metallic complexes were identified via UV–visible & FT-IR spectra. All metallic complex and (5-NTAMNP) ligand were screened for their biological activities.

Corrosion behavior of Ni/WC nano-structured composite layers synthesized by electrochemical method

Ni/WC nano-structured composite coatings were developed by electrodeposition method from a nickel plating electrolyte containing WC nanoparticles (diameter size of ~60 nm). The corrosion behavior of Ni/WC nano-structured composite coatings and pure Ni coating were comparatively investigated in wet conditions in the solution that simulates the primary water of Pressurized Water Reactors (PWRs). The morphology and chemical composition of the obtained coatings before was observed through scanning electron microscopy (SEM) connected to an energy dispersive X-ray system (EDX). The open circuit potential (OCP) and Electrochemical Impedance Spectroscopy (EIS) methods were used to evaluate the corrosion behavior, at room temperature. The nanohardness of pure Ni and Ni/WC nanocomposite coatings was tested by nanoindentation technique. SEM-EDX analyze proved that WC nanoparticles were successfully incorporated into Ni matrix. Presence of WC nanoparticles in the nickel matrix transforms surface morphology from regular pyramidal to irregular global and changes the crystallizations of nickel matrix to smaller and thinner crystallites. Ni/WC nanocomposite coating revealed a higher nanohardness value in comparison with pure Ni coating. The corrosion resistance of Ni/WC nanocomposite coating is higher under similar experimental conditions as compared with pure nickel layers, proving an enhancement of corrosion resistance.

EVALUATION OF WEAR AND CORROSION RESISTANCE OF TITANIUM AND STAINLESS STEEL JOINTS Made OF Al, Cu AND Ni

In the present study, commercial pure titanium (Grade 2) was joined to the stainless steel (X5CrNi18-10) by diffusion bonding using aluminium, copper, and nickel as interlayers (100 μm). The investigation focuses on comparing the wear and corrosion resistance of the obtained diffusion joints. The microstructure of the joints was investigated using scanning electron microscopy equipped with an energy dispersive X-ray system (EDS) to determine the chemical composition of joint. The value of friction force and the wear resistance of diffusion bonded joints were carried out by block-on-ring frictional pair, preformed on the tribological tester T-05. The study was carried out under conditions of technically dry friction for the concentrated sliding contact loaded with 300 N. The friction distance for each test was 400 m. The results show that the maximum values of the friction coefficient and mass loss were obtained for joints with a nickel interlayer. The galvanic corrosion tests were carried out in 0.5 M Na2SO4 solution acidified to pH 1 with a sulphuric acid solution. The potentiodynamic polarization curves show that the lowest corrosion current was registered for the joints performed by copper.

Evaluation of corrosion resistance of titanium/stainless steel diffusion joints bonded by interlayers made of pure metals

.The purpose of this study is to compare corrosion resistance of the joints between commercially pure titanium (Grade 2) and stainless steel (X5CrNi18-10) bonded by interlayers made of pure metals. Three different interlayers were used in the study, which were made of aluminium (Al 99.5), copper (Cu 99.99) and nickel (Ni 99.6). The diffusion bonding process has been employed to join those dissimilar materials. The microstructure of the joints were investigated using scanning electron microscopy equipped with an energy dispersive X-ray system (EDS). The phases of the reaction layers in the diffusion zone were identified by means of an X-ray diffraction (XRD).The structures of the joints varied importantly depending on the interlayer. The galvanic corrosion test was carried out in two solutions one in a 3,5% NaCl and second one in 1M Na2SO4 solution. The potentiodynamic polarization curves in a 3,5% NaCl solution show that the higher corrosion potential as well as a lower corrosion current were registered for the joints performed by nickel. The test carried out in 1M Na2SO4 solution show that that the lowest corrosion current was registered for the joints performed by copper and also all investigated samples have a tendency towards passivation.

Neat polyoxymethylene dimethyl ether in a diesel engine; part 2: Exhaust emission analysis

Oxygenated fuels have already shown potential to be used in Diesel engines without major modifications. Polyoxymethylene dimethyl ether (POMDME, short OME) possesses particular characteristics (i.e. no CC bonds, high cetane number, high potential to reduce greenhouse gases when produced with renewable energy, etc.), which are favourable for combustion in a standard Diesel engine, and offer the possibility to overcome the classical NOx-PM trade off. In order to capture the full potential of this fuel, its combustion characteristics under diesel engine conditions need to be investigated.In the present work, as the second of a two-part paper, the gaseous and particulate emissions of neat OME in a composition of approximately 80% OME3 and 20% OME4 have been studied. Numerous operating conditions have been recorded under globally stoichiometric conditions with simultaneously high EGR rates to evaluate the engine operation, suitable for a three-way catalyst. For the measurement campaign, a heavy duty single cylinder research engine has been used. In addition to standard exhaust gas measurement equipment, emissions have been recorded through fast mass spectrometer calibrated for methane, a particle spectrometer and transmission electron microscopy (TEM) of the solid particles.It is observed that CO and HC show an extreme spike in globally stoichiometric operation. Furthermore, the total HC emissions contain a substantial amount of methane. NOx emissions within the recorded operating conditions show a strong dependence on the applied EGR rate. The particle emissions using OME show high number (compared to the corresponding Diesel case in agglomeration mode) in a size range mainly below 20 nm. TEM imaging combined with an energy dispersive X-ray system revealed that these particles are mostly soot with a few nanometers large metal inclusions.

Acute Toxicity of Colloidal Silicon Dioxide Nanoparticles on Amphibian Larvae: Emerging Environmental Concern

Fil: Lajmanovich, Rafael Carlos. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina

Preparation of polyaniline-polyvinyl alcohol-silver nanocomposite and characterization of its mechanical and antibacterial properties

Abstract In the present research, polyaniline is used as a conducting polymer and polyvinyl alcohol is also used as a biopolymer, because of its mechanical properties and suitable processability. Also, silver nanoparticles are considered as a reinforcing agent of thermal stability, mechanical and antibacterial properties to prepare polyaniline-polyvinyl alcohol-silver nanocomposite. The synthesis of polyaniline-polyvinyl alcohol composite and polyaniline-polyvinyl alcohol-silver nanocomposite is performed through addition of polyaniline and silver in polyvinyl alcohol solution. In order to review thermal, mechanical and antibacterial properties of synthesized composite and nanocomposites, components with different weight rates are used. The obtained results from thermogravimetric analysis (TGA) tests also indicate promotion of thermal stability of polyaniline-polyvinyl alcohol-silver nanocomposite compared with pure polyvinyl alcohol in temperatures above 400°C. The results of Fourier-transform infrared (FTIR) spectroscopy revealed the presence of polyaniline, polyvinyl alcohol and silver in the structure of polyaniline-polyvinyl alcohol-silver triple nanocomposite film. The obtained results from a review of antibacterial properties showed that polyaniline-polyvinyl alcohol-silver nanocomposites have antibacterial effects on two different types of Gram-positive and Gram-negative bacteria. The obtained results from a review of mechanical properties of nanocomposites showed that the greatest value of tensile strength (13.8 MPa) belonged to polyaniline-polyvinyl alcohol-silver (88%/9%/3% w/w) nanocomposites. Therefore, this is determined as an optimal triple nanocomposite. In addition, scanning electron microscopy (SEM) coupled with an energy dispersive X-ray (EDX) system was used to characterize the composition and structure of polyaniline-polyvinyl alcohol-silver nanocomposite film.

Application of the mineral liberation analysis (MLA) for extraction of grain size and shape measurements in siliciclastic sedimentary rocks

The mineral liberation analysis setup (MLA) consists of a scanning electron microscope (SEM) - based backscattered electron (BSE) image with an energy dispersive X-ray system (EDX) for elemental analysis and a computer software that integrates images and X-ray identification of minerals and maps their distribution. Thereby, various quantitative and qualitative data sets are collected including grain size distribution and shape parameters such as aspect ratio, shape factor and angularity. Other techniques, e.g. the Gazzi-Dickinson point counting method or frequently questionable image analysis software to extract data for textural analysis are time consuming, strenuous and with limitations that need to be addressed. Significant productivity of the mineral liberation analysis provides statistical representation and thereby stringent arguments to detect and suggest some potential solving in uncertainty and complexity of the submarine gravity flows phenomenon that is extremely difficult to monitor, however volumetrically the most significant processes moving sediments on Earth. The mineral liberation analysis seems to be one of the most suitable method to acquire such data set.

Statistical Design Analysis of Silver-Titanium Dioxide Nanocomposite Materials Synthesized via Horizontal Vapor Phase Growth (HVPG)

This study aims to create a statistical design analysis of the synthesized Silver-Titanium dioxide nanocomposite materials using HVPG technique. The analysis was obtained to report the nature of nanomaterials produced for a specific growth time and temperature. The synthesized nanocomposite materials were characterized using the Scanning Electron Microscope and Energy Dispersive X-ray system. Using the JMP ANOVA Software, the experimental results revealed an empirical equation to predict the behavior of the synthesized material formed at different growth zones.