X-ray Diffraction Spectrometer Research Articles

X-ray diffraction and SEM analysis of waste sulfur modification for use in concretes

Secondary sulfur obtained as a by-product in the oil refining process is a major problem as an environmental pollutant. One of the possibilities of environmental protection is the use of sulfur obtained in this way as a component of sulfur concrete. Mixing of sulfur with suitable additives can provide longer working lifetime of sulfur concrete, as well as maintenance of the former physical, chemical, and mechanical properties of concrete. Such mixtures are usually called modified sulfur or sulfur cement. Secondary sulfur produced in the oil refining process by the Klaus process (approval of crude oil) cannot be used in this form. In order to be ready for the use of sulfur concrete and asphalt, it is necessary to modify elemental sulfur from cyclic to chain form, obtaining of modified sulfur whose application is as a binding agent in a concrete instead of portland cement is described in this paper. Influence of dicyclopentadien, an organic additive, on sulfur modification has been studied in this research. Microstructure and mineral analysis of modified and unmodified sulfur cement binding are performed using polarized and scanning electron microscopes and X-ray diffraction spectrometer.

Investigate the deformation mechanisms and microstructural development of produced titanium alloys – A review plasma sintering technology

Abstract Titanium and its alloys possess excellent properties in the form of high strength-to-weight ratio, high fracture toughness, and high elevated temperature strength and are exceptionally resistant to corrosion. Many researchers have since investigated the morphology and the mechanical and corrosive properties of Ti6Al4V alloy reinforced with various ceramic particulates such as SiC, TiC, TiB2, Al2O3, Si3N4, Y2O3, B4C, etc. Titanium and its alloys may have good fatigue, high strength, and good oxidation and corrosion resistance properties, they had a wide application in aero/space and power generation industries. Ti-alloys are excellent structural materials, which fulfil the requirements of lowering fuel costs. Frequent use of Ti-alloys, moving towards the advancement of the next-generation engines. And it is not only reducing the structural weight but also helping in improving the safety standard. The present study includes the preparation of Ti and its alloys by the Spark Plasma Sintering process, which appears to be a promising route to produce Ti-alloys for structural applications. However, owing to the short duration of the process, the diversity and control of microstructures are limited concerning other processes. Though it is this short duration of the process which attributes several advantages at the same time such as producing refined microstructure ensuring rapid turnaround and low-cost. The microstructural evolutions of the synthesized sample were evaluated with the help of a scanning electron microscope (SEM). The phases present in the fabricated sintered composites were observed by an energy-dispersive X-ray diffractionspectrometer (XRD). These efforts may help in developing new alloys and their applications especially for Ti-alloys in aero/space engine in multiple performances such as strength, toughness, creep resistance, fatigue life, and other properties.

Characteristics of Field-Emission Emitters Based On Graphene Decorated ZnO Nanostructures

This paper investigated that the preparation of zinc oxide (ZnO) nanorod (NR) and ZnO NR with graphene material was successfully prepared and explored. The ZnO NRs without and with decorated graphene are also called ZO and ZO-G field-emission (FE) emitters. Besides, the material properties of fabricated ZO and ZO-G NR arrays were characterized by X-ray diffraction (XRD) spectrometer, X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscope (FE-SEM), Raman spectrometer, and high-resolution transmission electron microscope (HR-TEM) with energy dispersive X-ray (EDX) spectrometer. It was observed that all NRs exhibited the single crystal performance and were uniformly grown on the surface of seed layer. Simultaneously, the samples were victoriously decorated by graphene on the NR surface. As a result, decorating with graphene reduced turn-on field from 6.06 to 4.12 V/μm. The effective field enhancement factors of the ZO and ZO-G NRs estimated from the slopes of the Fowler-Nordheim (F-N) plot were approximately 3682 and 7462. Additionally, the UV light treatment can also enhance FE characteristics. The results indicated that these emitters will be useful in FE applications.

Nanoporous RuO2 characterized by RuO(OH)2 surface phase as an efficient bifunctional catalyst for overall water splitting in alkaline solution

Abstract With the demand of renewable hydrogen energy, electrocatalytic water splitting is considered as the most promising method for hydrogen production. Herein, a simple synthesis of the nanoporous RuO2 (NP-RuO2) characterized by RuO(OH)2 surface phase was reported. The physical characterization of the materials are achieved by transmission electron microscope (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray fluorescence (XRF) and X-ray photoelectron spectrometer (XPS). For HER activity, the NP-RuO2–450 electrode only needs 87 mV overpotential to obtain a current density of 10 mA cm−2, while RuO2 generates the same current density at a relatively large overpotential (η = 142 mV). Notably, the HER activity of NP-RuO2–450 is also higher than that of Pt (10 mA cm−2, η = 103 mV). The specific activity of NP-RuO2–450 is still 2.4 times higher than that of RuO2 reflecting the enhancement of the intrinsic activity. The OER activity of NP-RuO2–450 electrode has outperformed that of RuO2. The apparent activity of NP-RuO2–450 is 3.5 times that of RuO2 at an overpotential of 270 mV. For the specific activity, NP-RuO2–450 is still 1.9 times higher than that of RuO2. Therefore, NP-RuO2–450 electrode could be used as a bifunctional catalyst for overall water splitting. The excellent HER and OER activities of the NP-RuO2–450 electrode could be attributed to the enhancement of electrochemical surface area of electrode material. However, the more important reason is that the new surface phase creation of hydroxides and the electronic structure modification of Ru.

Enhancement in structural, optical and morphological properties of sprayed In2O3 thin films induced by low energy electron beam irradiation

In2O3 thin films have been synthesized on glass substrates by spray pyrolysis then irradiated by electron beam (EB) at low energy of 0.8 MeV for three fluencies 4.1016, 35.1016 and 42.1016 electron/cm2. EB irradiation was performed by an industrial electron accelerator owned to COFICAB Company. Structural, optical, photoluminescence and morphological properties of In2O3 thin films have been investigated before and after EB irradiation by X-ray diffraction, spectrophotometer, SEM and fluorescence spectrometer. After EB irradiation at 4.1016 electron/cm2, the preferred orientation of In2O3 thin film was moved from (222) to (400) with a simultaneous improvement in grain size. For EB fluency of 35.1016 electron/cm2, In2O3 thin film has been strangely transformed from polycrystalline phase to a single crystal structure. After irradiation at 42.1016 electron/cm2 fluency, In2O3 thin film became amorphous. A clear enhancement in optical transmission has been observed after irradiation with a slight variation in band gap energy. Surface morphology of the irradiated In2O3 thin films has been transformed from rough to continuous, uniform and smooth surface. This study have shown that EB irradiation can be considered as a useful mean for enhancement of In2O3 thin films physical properties and suggest its use for the space optoelectronic applications.

Polydopamine Mediated Growth of Ag Nanostructures on ZnO Thin Films for Catalytic Degradation of Organic Dyes

In this study, multi-functional films were produced by the solution-phase growth of plasmonic Ag nanostructures (NSs) on ZnO fabricated by RF magnetron sputtering technique. The Ag NSs was grown on ZnO coated surface by functionalizing the thin film with mussel-inspired polydopamine. The structural analysis was performed by Grazing Incident X-ray diffraction (GIXRD) and Fouirer Transform Infrared Spectrometer (FTIR) technique in order to observe the effect of the Ag NSs deposition times. The effect of growth conditions on the structure and size of Ag NSs was investigated by Field Emission Scanning Electron Microscope (FESEM) imaging technique. The chemical compositions of as-deposited and Ag decorated ZnO films confirms using Energy-dispersive X-ray spectroscopy (EDX) analysis. The catalytic performance of the multi-functional films was investigated by the degradation of organic dyes (methyl orange (MO) and rhodamine B (RhB)).The catalytic activity of Ag on the is examined in details where it is found that maximum catalytic performance was observed within first 15 min for the ZnO thin films that were decorated with Ag NSs for 24h. The rate constant for the degradation reaction was 33.8x10-3 min-1 and 43.2x10-3 min-1 for MO and RhB, respectively. These results show the promise of integrating metal oxide films with plasmonic structures for efficient degradation of organic dyes.

Effect of Ti on the corrosion behaviour of as-cast Fe–17Cr ferritic stainless steel

ABSTRACT The effect of Ti addition on the microstructure and corrosion resistance of the as-cast Ti-stabilised Fe–17Cr ferritic stainless steels was investigated by optical microscopy, scanning electron microscopy, X-ray diffraction and energy-dispersive spectrometer. The corrosion behaviour of the as-cast Fe–17Cr ferritic stainless steel in 10 wt-% HNO3 and 10 wt-% NaOH solutions was examined by using potentiodynamic polarisation curves and electrochemical impedance spectroscopy. After Ti addition from 0.06 to 0.26 wt-%, the size of TiN precipitates in the as-cast Fe–17Cr ferritic stainless steel increases and the corrosion resistance is improved in 10 wt-% HNO3 and 10 wt-% NaOH solutions, especially in 10 wt-% HNO3 solution. Mott–Schottky curves demonstrate that the addition of Ti can inhibit the decomposition of the passive film, which can improve corrosion resistance.

Simultaneous removal of Cr(VI), Cd, and Pb from aqueous solution by iron sulfide nanoparticles: Influencing factors and interactions of metals

• Cr(VI), Cd, and Pb may be removed from aqueous solutions simultaneously by FeS NPs. • Acidic pH values favor Cr(VI) removal, and alkaline pH values favor Cd and Pb removal. • Oxygen inhibits Cr(VI) removal, but does not influence Cd and Pb removal. • The interactions between Cr(VI), Cd, and Pb involve enhanced adsorption and precipitation. Cadmium (Cd), lead (Pb), and hexavalent chromium (Cr(VI)) are often found in soils and water affected by metal smelting, chemical manufacturing, and electroplating. In this study, synthetic iron sulfide nanoparticles (FeS NPs) were stabilized with carboxymethyl cellulose (CMC) and utilized to remove Cr(VI), Cd, and Pb from an aqueous solution. Batch experiments, a Visual MINTEQ model, scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectrometer (XPS) analysis were used to determine the removal efficiencies, influencing factors, and mechanisms. The FeS NP suspension simultaneously removed Cr(VI), Cd, and Pb from an aqueous solution. The concentrations of Cr(VI), Cd, and Pb decreased from 50, 10, and 50 mg·L −1 to 2.5, 0.1, and 0.1 mg·L −1 , respectively. The removal capacities were up to 418, 96, and 585 mg per gram of stabilized FeS NPs, respectively. The acidic conditions significantly favored the removal of aqueous Cr(VI) while the alkaline conditions favored the removal of Cd and Pb. Oxygen slightly inhibited the removal of Cr(VI), but it had no significant influence on the removal of Cd and Pb. A potential mechanism was proposed for the simultaneous removal of Cr(VI), Cd, and Pb using FeS NPs. The interactions of the three heavy metals involved a cationic bridging effect on Cr(VI) by Cd, an enhanced adsorption effect on Cd by [Cr,Fe](OH) 3 , precipitation of PbCrO 4 , and transformation of PbCrO 4 to PbS. Therefore, FeS NPs have a high potential for use in the simultaneous removal of Cr(VI), Cd, and Pb from contaminated aqueous solutions.

Controllable luminescence and efficient energy transfer investigation of a novel white light emission phosphor Ca19Na2Mg(PO4)14: Dy3+, Tm3+ with high thermal stability

White light emission phosphors are widely researched for application in lighting and display fields. However, the poor thermal stability is a real problem for the known single-phased white phosphors, which limits their further application. In this paper, Ca19Na2Mg(PO4)14: xDy3+, yTm3+ (CNMP, 0 ≤ x ≤ 0.06, y = 0, 0.01) phosphors with adjustable emission and good thermal stability are synthesized. The X-ray diffraction and X-ray energy dispersive spectrometer measurement distinctly confirm the successful synthesis of CNMP: xDy3+, yTm3+ (CNMP, 0 ≤ x ≤ 0.06, y = 0, 0.01). The photoluminescence results reveal that CNMP: Dy3+ shows characteristic excitation peaks in the range of 350–450 nm, and mainly exhibits strong yellow emission around 575 nm ascribed to the 4F9/2-6H13/2 transitions of Dy3+. To compensate the deficiency of blue light emission of CNMP: Dy3+, the trivalent Tm3+ ion is co-doped owing to its characteristic blue emission at 450 nm due to its 1D2-3F4 transitions. Therefore, the emission of CNMP: Dy3+, Tm3+ can be tuned from blue light region with CIE coordinates of (0.1649, 0.0387) to white light region with CIE coordinates of (0.3001, 0.3003) and finally move to yellow light region with CIE coordinates of (0.3732, 0.4493) through adjusting the doping ratio of Dy3+/Tm3+. The energy transfer efficiency and the energy transfer mechanism from Tm3+ to Dy3+ are further investigated. Moreover, CNMP: Dy3+, Tm3+ exhibites a high thermal stability and the emission intensity still keeps 84% of the initial intensity of Dy3+ at 230 °C. These outstanding properties show that Ca19Na2Mg(PO4)14: Dy3+, Tm3+ have great advantages and potentiality for applying in solid state lighting.

Improved mechanical properties of resistance welded joints of thermoplastic composites by versatile graphene oxide

An approach of adding graphene oxide (GO) nanosheets to enhance the joints for resistance welding glass fabric reinforced polyetherimide (GF/PEI) laminates was proposed in this study. The GO nanosheets were introduced and dispersed uniformly into the heating element (HE) of carbon fiber (CF) bundles coated PEI and the welding adhesives of PEI films in the different weight ratios. The GO nanosheets were prepared firstly by the modified Hummers method. Then their morphology and structure were also confirmed by the combination of a scanning electron microscope, Fourier transform infrared spectrometer, X-ray diffraction and Raman spectrometer. The lap shear strength (LSS) obtained from single lap shear specimens and fracture morphology are reported to evaluate the optimum welding parameters, such as input power, heating time and pressure. Finally, the effect of GO on the LSS of the welded samples was studied. The results showed that the LSS of joints was increased by adding GO to the welded joint, but if it exceeded the optimal value, they were more vulnerable to damage.

Preparation of nano Fe3O4 pigment using CO32−/HCO3− as precipitant and DFT study on the formation process of its intermediate product FeOOH

The nano Fe3O4 pigment was prepared with a precipitation method using the carbonate/bicarbonate as precipitant. The chemical structure, crystal phase and morphology of prepared pigment samples were determined by fourier transform infrared spectroscopy (FT-IR), X-ray diffraction spectrometer (XRD), transmission electron microscope (TEM), high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED), and its color performance was tested. The results showed that the prepared pigment sample showed high purity and excellent crystallinity of bulk Fe3O4, and better black property (L* = 35.51) than the commercially available standard pigment sample. The characterization results of pigment samples obtained under different preparation parameters showed that the precipitant reaction temperature and reaction time showed obvious effect on the morphology, crystallization degree and color performance of prepared nano Fe3O4 pigment. In addition, it was found that the FeOOH was the intermediate product. The density functional theory (DFT) calculation results revealed that the generation of FeOOH was realized through a series of reaction steps including dehydrogenative oxidation, dehydration, and dimerization, in which the FeCO3 instead of the Fe(OH)2 was served as the initial phase of Fe(II) compounds.

Preparation of TiO<sub>2</sub> Decorated Eggshell Membrane for Photocatalytic Dye Degradation

Pristine ESM was impregnated with TiO2 using the wet chemical method and subsequently calcined at 700 °C. All prepared samples were characterized using Field Emission Scanning Electron Microscope (FESEM), X-ray Diffraction (XRD) and UV-visible Spectrometer. FESEM images indicate the presence of a fibrous network that introduces useful adsorptive and photocatalytic properties for organic pollutants removal from water. The XRD result indicated that the TiO2 nano-composite contained only anatase and rutile phase. Photocatalytic results revealed that the photocatalytic activity of TiO2 increased under visible light irradiation in the presence of the carbonized eggshell membrane. It is found that TiO2-CESM produced the highest photocatalytic degradation of 93 % within 5 hours of irradiation time.

Using Dates Leaves Midribs to Prepare Hierarchical Structures Incorporating Porous Carbon and Zeolite A Composites for Cesium137Cs Ion Exchange

This study synthesized zeolite 4A, and hierarchical composite structure consisting of zeolite 4A- carbon were successfully prepared. Hydrothermal method was used to grow a layer of zeolite 4A over porous carbon surfaces to enhance mass transfer and increase surface area of zeolite. The products then were used to remove radioactive cesium137Cs from liquid wastewater. Iraqi dates leaves midribs (DM) were used as locally available agricultural waste to prepare low- cost porous carbon, using carbonization method in tubular furnace at 900C for two hours. Hierarchical porous structures including zeolite are prepared by mechanically activating the carbon surface via Ultrasonicating nanoparticles suspension of ground zeolite type 4A.For preparing nanoparticles suspension, commercial zeolite has been milled using 0.3-0.4 mm diameter glass balls as grinding media. Nanoparticles of zeolite 4A acting as seeding (nucleation centers) increase the crystallization of amorphous aluminosilica gel on modification carbon surface. The products of the syntheses zeolite 4A and the hierarchal composite materials (DMZ) were characterized using Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Nitrogen sorption (BET) and Energy dispersive X-ray spectrometer (EDX) to check the morphology, structure, surface area, and the chemical composition respectively. The products were used to treat radioactive wastewater contaminated with radioactive cesium 137Cs collected from destroyed building of the Radiochemistry Laboratories (RCL) in AL-Tuwaitha Nuclear Site. The activity concentration for the contamination water pre and after the treatment were measured using gamma spectroscopy system supplied with a high purity germanium detector (HPGe) with 60% relative efficiency. The results showed that the radioactivity concentration after the treatment process decreased significantly from 4800 Bq/L to 186 and Bq/L,121 Bq/L using 0.045 gm from synthesized zeolite 4A and DMZ respectively.

Microstructure of HVOF-sprayed Ag–BaF2⋅CaF2–Cr3C2–NiCr coating and its tribological behavior in a wide temperature range (25 °C to 800 °C)

Ag–BaF2⋅CaF2–Cr3C2–NiCr composite powders were prepared by physically blending commercial BaF2⋅CaF2–Cr3C2–NiCr and Ag powders. Ag–BaF2⋅CaF2–Cr3C2–NiCr composite coatings were deposited on Inconel 718 alloy substrate by high velocity oxy-fuel (HVOF) spraying. The friction and wear behavior of the coatings under dry sliding against Si3N4 balls from 25 °C to 800 °C was evaluated with a ball-on-disk high temperature tribometer. The microstructure and composition of the samples were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectrometer. Results showed that the composite coatings were mainly composed of hard phase of Cr3C2, binder phase of NiCr, high-temperature lubrication phase of fluorides and low-temperature lubrication phase of Ag. The fluorides existed in the forms of both crystal particles and amorphous state, while the silver featured as typical thermally sprayed splats. Due to the high flame temperature, some fluorides have been oxidized to chromates and around 30 wt% of Ag was lost during spraying. In addition, it was found that Ag content had an important influence on the composite coating, and an appropriate dosage of metallic silver could effectively improve the tribological performance of the coating. The generation of AgCrO2 at moderate (500 °C and 650 °C) temperature and BaCrO4 at high temperature (800 °C) could contribute to the decline in friction coefficients and wear rates of Ag–BaF2⋅CaF2–Cr3C2–NiCr coatings.

Fabrication of amperometric sensor for glucose detection based on phosphotungstic acid–assisted PDPA/ZnO nanohybrid composite

Amperometric sensor of polydiphenylamine (PDPA)/phosphotungstic acid (PTA)/zinc oxide (ZnO) on glassy carbon (GC) nanohybrid composite electrode (GC/PDPA/PTA/ZnO) fabricated via facile electrochemical deposition method. The structural geometry and surface morphology were recorded by X-ray diffraction spectrometer (XRD) and scanning electron microscopy (SEM). Electro-catalytic properties and performances of nanohybrid composite were recorded by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry (CA) methods. PTA-assisted PDPA/ZnO-ME shows linear steady-state response towards glucose with superior sensitivity of 20.30 μA μM−1 cm−2, lowest detection limit 0.1 μM, and rapid response less than 2 s. The improved electro-catalytic performance towards glucose by GC/PDPA/PTA/ZnO is due to the combined existence of diphenoquinone diamine (DPDI2+) and phosphotungstic acid anion which provides a higher electro-catalytic active spots leads to more electron transport pathway for the oxidation of glucose. Interference analyses confirm the prepared nanohybrid sensor is best apt for glucose detection claims its practical biomedical application.

A α-Fe2O3/rGO magnetic photocatalyst: Enhanced photocatalytic performance regulated by magnetic field

The magnetic photocatalyst α-Fe2O3/reduced graphene oxide (rGO) was constructed to enhance the photocatalytic efficiency by the magnetic field. The results of X-ray diffraction spectrometer (XRD), Raman and high resolution transmission electron microscope (HRTEM) indicated the successful preparation of the α-Fe2O3/rGO composite photocatalyst, and the enhanced optical absorption for visible light after the growth of rGO was also demonstrated by UV–vis spectrophotometer. The introduction of rGO enhances the transfer of photogenerated carriers, and the interface effect between α-Fe2O3 and rGO makes the photocatalyst having a stronger magnetization intensity and larger negative magnetoresistance (MR) than pure α-Fe2O3, thus the introduction of magnetic field can further improve the transfer of carriers. When the mass ratio of α-Fe2O3 and rGO was 10:1, the α-Fe2O3/rGO composite photocatalyst could reach the best photocatalytic performance, i.e. degrading 60% of Congo red (CR) after visible light irradiation of 30 min, and its photocatalytic performance was much better than that of other photocatalysts with different rGO concentration. With the magnetic field of 1000 Oe, the α-Fe2O3/rGO (10:1) composite photocatalyst could degrade 87% CR under visible light which was higher than that without the magnetic field, indicating the efficient magnetic effect on the photocatalytic reaction of α-Fe2O3/rGO (10:1). These results will provide a new perspective for developing efficient photocatalyst, and make it possible to further improve the performance of existing photocatalysts.

Synergistic use of industrial solid wastes to prepare belite-rich sulphoaluminate cement and its feasibility use in repairing materials

This paper investigated the feasibility of belite-rich sulphoaluminate cement prepared from Bayer red mud, blast furnace slag, steel slag, flue gas desulfurization and carbide slag on synergistic theory. X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive spectrometer (SEM-EDS) were used to analyze the phase composition of clinkers and determine the optimum calcination temperature and holding time. The influence of gypsum content on the performance of clinker was studied by compressive strength test. The properties of synthetic cement were characterized by XRD, SEM-EDS, isothermal calorimetry, and mechanical test. The results showed that the optimum calcination temperature and holding time of synthesis cement were 1300 °C and 60 min, respectively. The formed phases in the clinkers were ye'elimite (10 wt% C4A3Ŝ), larnite (60 wt% β-C2S), brownmillerite (9 wt% C4AF), and mayenite (21 wt% C12A7). The main hydration products were ettringite. The compressive strength of synthetic cement in 28 d was 29.3 MPa when gypsum content is 20 wt%. The total hydration heat output of synthetic cement was lower than ordinary Portland cement (OPC) and sulphoaluminate cement (SAC), and its early hydration behavior was better than that of SAC and OPC at the initial 11.8 h and 58.6 h, respectively. And the test showed that the belite-rich sulphoaluminate cement is feasible in the application of repair materials.

Spontaneous Symmetry-Breaking in the Corrosion Transformation of Ancient Bronzes

In general, during long-term museum conservation, ancient bronzes will generate new corrosion products also called the “secondary corrosion” on the surface of the unearthed “primary corrosion” products due to various environmental conditions. In this paper, the corrosion stages of several ancient Chinese bronzes are characterized by using optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and Raman spectrometer (Raman). It is found that there exist phase transformation relationships in between the “primary corrosion” and the “secondary corrosion” stages (i.e., (1) the crystal lattice type tends to transform from a high symmetry system to a low symmetry system; (2) in case of the same crystal lattice type, the corrosions exhibit an inter-transformation or symbiosis). It is interesting to note that these transformation rules are very consistent with the well-known physical law of “spontaneous symmetry-breaking”, which won the 2008 Nobel Prize in Physics and also has been considered to be general law of nature, in addition to the principle of Gibbs free energy reduction. The significance of this discovery allows us to achieve the predictability and controllability of the bronze corrosion products (i.e., to predict the corrosive trends in advance and control the “second corrosion” by adjusting the conservation conditions. This research provides a novel conservation concept of ancient bronzes.

Development of Aluminium-Nanoclay Composite by Using Powder Metallurgy and Hot Extrusion Process

It is well-known that Al matrix nanocomposites are always more expensive compared to conventional materials. In this study, the Al matrix composite containing montmorillonite Nanoclay reinforcement has been synthesized, which is cheaper and more abundant than other reinforcements. Powder metallurgy and extrusion process were employed for the production of the nanocomposite samples containing 0%, 1%, 2%, 6%, and 10% Nanoclay. Microstructural evaluations were carried out by using optical and scanning electron microscopy. Phase investigation was done by using X-ray diffraction and energy-dispersive X-ray spectrometer methods. Mechanical evaluations including macro- and micro-hardness, density evaluation, tensile and compression tests were also conducted. It was revealed that aluminium-clay nanocomposite properties were higher than the monolithic type. According to the obtained results, the addition of montmorillonite Nanoclay caused improvement of the mechanical properties, due to the mechanisms like Orowan and thermal expansion mismatch between reinforcement and the matrix. Thus, the ultimate tensile strengths of 1%, 2%, 6%, and 10% Nanoclay samples were increased about 31%, 46%, 62%, and 95%, respectively, than 0% Nanoclay specimen. The sample containing 2% Nanoclay represented the optimum properties which were the increase in hardness, tensile and compressive strengths about 63%, 46% and 53%, respectively. The increase in the Nanoclay content of the Al matrix changed the complete ductile fracture mode to the shear ductile type.

Microstructure and chemical analysis of NOx and particle emissions of diesel engines

This study was carried out to investigate the micro and chemical structure of particulate matter and nitrogen oxide from motor vehicle exhaust fumes. In this context, particulate matter microstructure was determined with the help of scanning electron microscope; elements such as C, O, N, F, Na, Mg, Br, Al, Si, Hg, S, Pb, Cl, Cd, K, Ca, Ba, Ti, V, Mn, Fe, Ni, V and Zn which constitute the source of pollution were determined by energy dispersive spectrometer; nitrogen oxide compounds were determined with X-ray diffraction spectrometer; and photonic properties were determined by means of photoluminescence spectrophotometer. The data obtained in this study provide important source information to understand the effects of exhaust fume on environmental pollution.