Scanning Electron Microscopy With Energy Dispersive X-ray Analysis Research Articles

Production technique and multi-analytical characterization of a paint-plastered ceiling from the Late Antique villa of Negrar (Verona, Italy)

The research focuses on analyzing the production techniques and materials of a Roman paint-plastered ceiling from a Late Antique Roman villa near Negrar (Verona, Italy), recently uncovered. Stylistic features of the decoration, found in reworked collapse debris during the villa’s excavation, date the ceiling to the original construction phase in the 4th century CE. The paper presents the protocol we adopted for recovering and analyzing the painted decoration of the villa, which was in-laboratory recomposed in its original layout after a meticulous and systematic retrieval of fragmented materials. Microsamples of mortar and pigment were then taken to fully reconstruct the execution technique and raw materials used in the paint-plastered ceiling, detailing the application of the tectorium and pigment preparation. Mortar samples were analyzed to define preparatory layer properties, using various analytical techniques including Transmitted-Light Polarized Optical Microscopy (TL-OM) and Scanning Electron Microscopy with Energy Dispersive X-Ray Analysis (SEM-EDS). Optical reflected-light microscopy detected guide incisions on the preparatory mortar, while Reflected-Light Optical Microscopy (RL-OM) revealed the microstratigraphy of pictorial micro-layers. Micro-samplings of painted decorations were conducted to define pigment palettes, determining their mineralogical composition through X-Ray Powder Diffraction (XRPD) analysis coupled with micro-Raman analyses for the determination of carbon-based compounds. The research aims to establish a comprehensive protocol for future endeavors, integrating archaeological reassembly with precise micro-analyses of pigments and mortars, deciphering the intricate layout of ancient, fragmented decorations. This study is the first of its kind in Northern Italy, overcoming challenges posed by fragmented and reworked artifacts in previous research, enabling detailed analytical studies like those conducted here. Moreover, this study of the paint-plastered ceiling of the Late Roman villa of Negrar aims to provide a new impulse for the knowledge of Late Antique painting techniques and materials, which were only marginally considered within Roman painting tradition so far.

Performance Evaluation of Various Filter Media for Multi-Functional Purposes to Urban Constructed Wetlands

The escalating demand for innovative solutions is driven by the challenges posed by water quality degradation and the pervasive impacts of climate change. As such, this study evaluated the performance of filter media to mitigate these challenges through multi-functional applications in urban constructed wetlands (UCWs). Column testing of organic filter media, including biochar (BC), woodchip (WC), anthracite (AT), and activated carbon (AC), as well as inorganic filter media, such as ceramic balls (CB), basalt (BS), and porous sand (PS), with synthetic stormwater runoff influent was conducted to assess their performance through water quality parameters and Scanning Electron Microscopy with Energy Dispersive X-ray (SEM-EDX) analysis for carbon storage potential. Among the media tested, AC exhibited high pollutant removal efficiencies amounting to 84%, 54%, 56%, and 44% for total suspended solids (TSS), chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP), respectively. For inorganic media, PS had the highest TSS and TN removal, whereas BS exhibited the highest COD and TP removal. Overall performance rating revealed that AC and BS, despite their efficient pollutant removal, are associated with higher costs, resulting in a lower ranking compared to AT and PS. SEM-EDX analysis identified PS and AC as standout media for potential carbon storage, attributed to their extensive surface areas and pore structures providing abundant adsorption sites. The results from this study highlighted the potential applications of various filter media in UCW designs with the aim of achieving carbon neutrality and sustainable urban development.

Histology, prevalence, and environmental sources for pulmonary silicates depositions in domestic and wild animals.

The source and significance of pulmonary silicate crystals in animals and people are poorly understood. To estimate the prevalence and characterize the pulmonary crystalline material in animals from St. Kitts, tissue samples from dogs, horses, cattle, sheep, goats, pigs, chickens, mongooses, and monkeys were examined by light microscopy, scanning electron microscopy with energy-dispersive x-ray analysis (SEM/EDXA), and x-ray diffraction. Crystalline material was seen in 201 of 259 (77.6%) lung samples as perivascular and interstitial accumulations of heterogeneous crystalline particulate material, free or within macrophages (silicate-laden macrophages [SLMs]), mostly lacking evidence of chronic inflammation or fibrosis. The crystalline material was birefringent, basophilic on acid-fast, and composed of silicas on SEM/EDXA. Mongooses (100%) and monkeys (98%) had the highest prevalence of SLM, followed by cattle and chickens. Lesions were graded on a 3-point scale based on the histologic location and extent of silicates and SLM and were significantly more severe in mongooses (median = 3) than in monkeys (median = 2), dogs (median = 2), and chickens (median = 1). On EDXA, the crystalline material from lungs, air, and topsoil was composed of silicon, oxygen, aluminum, and iron, with a particulate matter size between 2.5 and 10 µm. We hypothesize Saharan dust, volcanic ash, topsoil, and rock quarry dust are potential sources of siliceous dust inhalation and SLM accumulations lacking chronic inflammation (silicosis); dust generation may be potentiated by road vehicle or wind suspension. Future investigations are warranted on the role of silicate inhalation and respiratory comorbidities in people, with monkeys, mongooses, or chickens serving as possible sentinels for exposure.

Fracture properties of tailings-based geopolymer incorporated with class F fly ash under mode I loading conditions

As a potential alternative of Portland cement concrete for construction and building applications, solid-like geopolymer made by alkali-activation of the mine tailings (MTs) shares the similar brittle properties with rocks and concrete. However, the pure MTs did not have sufficient amorphous aluminosilicates for better alkali activation. It is essential to add some materials as the source of amorphous aluminosilicates for better reactivity to adjust the geoploymeric cell structures and improve the cementitious properties. In this study, class F fly ash (FA), was utilized as the amorphous supplements source to improve the alkali reactivity to enhance the mechanical and fracture properties. FA and MTs were first characterized by conducting a series of laboratory tests, such as traditional geotechnical tests, X-ray diffraction (XRD) analysis, and scanning electron microscopy with Energy dispersive X-ray analysis (SEM-EDS) analysis. The geopolymer with different FA additions were created by activating the FA-MTs mixtures with 10 M NaOH solutions at the moisture ratio of 16% and then cured for 7 days with the slightly elevated temperature. The semi-circular bending tests (SCB) were then conducted to evaluate the influences of different FA additions on the fracture behavior of the geopolymer. In additions, digital image correlation (DIC) was applied to obtain the strain behaviors and crack propagation properties of the geopolymer. The influence of FA additions on the crack tip opening displacement (CTOD) and fracture process zone (FPZ) were also investigated. Results show that at currently curing condition, the supplements of class F FA will not improve the KIC at lower additions but increased with higher FA additions. The links between microscopic insights and fracture behaviors of the geopolymer with inclusion of FA were also discussed.

Effect of strontium on nutrient uptake, physiological parameters, and strontium localization in lettuce.

Human activities increase the risk of stable and radioactive strontium (Sr) isotopes entering the environment and food chain. In this study, the effects of Sr on the nutrient uptake and physiological responses of lettuce under different "Sr treatment" concentrations (0, control, 1, 2, 3, 4, and 5mM) and "times" (7, 14, and 21day) were studied in a hydroponic system. In addition, the distribution of Sr on the surfaces and cross-sections of lettuce leaves was revealed by scanning electron microscopy with energy-dispersive X-ray (SEM-EDX) analysis. A two-way analysis of variance (ANOVA) method was used to analyze the significance of "Sr treatment," "time," and their "interaction." The results showed that an increase in Sr uptake in lettuce could significantly reduce the uptake of calcium (Ca). The contents of sulfur (S), potassium (K), and iron (Fe) in lettuce leaves showed significant differences with the sampling day. Similarly, the fresh weight of lettuce leaves and roots as well as the photosynthetic pigment contents of lettuce leaves was also significantly different with the sampling day. The activities of antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD)) showed significant differences with the sampling day. The activities of SOD and CAT decreased significantly with the sampling day, while POD increased significantly. The MDA content increased significantly with increasing hydroponic Sr concentration on the 21st day. SEM-EDX analysis showed that the weight percentage of Sr in the vascular bundle sheath in the cross-section of lettuce leaves was relatively higher than that in the mesophyll. This study aids our understanding of the distribution of Sr in lettuce leaf tissues and the effect of Sr on lettuce physiology.

On the incorporation of class F fly-ash to enhance the geopolymerization effects and splitting tensile strength of the gold mine tailings-based geopolymer

Mine tailings (MTs) are ore residuals after valuable metals were extracted during mineral processing, which can be reused to produce the geopolymer concrete for construction and building applications, to mitigate the storage, economic, and environmental pressures. However, the pure MTs did not have enough reactive aluminum or amorphous aluminosilicates for better geopolymerization effects. It is necessary to add other materials as the additional aluminum source and amorphous additives to change the Si: Al ratio for better geopolymerization. In this study, class F fly ash (FA) was utilized as the additional aluminum source to adjust the Si: Al ratio for better geopolymerization effects. Raw materials (MTs and FA) were first characterized by performing a series of laboratory tests, such as X-ray diffraction (XRD), scanning electron microscopy with Energy dispersive X-ray analysis (SEM-EDS) and Fourier-transform infrared spectroscopy (FTIR). The Brazilian indirect tensile tests (BT) were conducted to evaluate the influence of different FA additions, 5%, 10%, 15%, and 20%, on the tensile strength of the geopolymer. Moreover, the microscopic morphological, chemical, and mineralogy properties of the geopolymer with different FA additions were evaluated by using SEM/EDS and FTIR respectively. Finally, digital image correlation (DIC) was used to track the strain behavior of the specimen surface during BT loading. Results show that at currently moisture content, the adding of FA can increase the mechanical behavior. However, due to the lacking of water for addition geopolymerization, the tensile strength of the geopolymer when adding 20% FA decreased comparing to 15% FA addition. The splitting tensile strengths experience a first increase followed by a decrease with the FA addition at current water to MTs ratio. SEM micrographs show that the geopolymer gel was getting more homogeneous when adding FA. FTIR spectrums show that the absorption band shift at 1000 cm−1 indicates the formation of new produced amorphous geopolymer phase.

Particle Analysis by Scanning Electron Microscopy With Energy Dispersive X-Ray Analysis in Pulmonary Pathology Specimens From U.S. Military Service Members Deployed During the Global War on Terror 2002 to 2015.

Between 2001 and 2015, 2.77 million U.S. military service members completed over 5 million deployments to Southwest Asia. There are concerns that deployment-related environmental exposures may be associated with adverse pulmonary health outcomes. Accurate pulmonary diagnosis often requires histopathological biopsy. These lung biopsies are amenable to chemical analysis of retained particulates using scanning electron microscopy with energy dispersive X-ray analysis (SEM/EDXA). A retrospective review of SEM/EDXA data collected in conjunction with pathologic diagnostic consultations at the Joint Pathology Center from 2011 to 2016 was conducted. Sections adjacent to those obtained for pathologic diagnosis were prepared for SEM/EDXA particle analysis, which provides qualitative identification of elements present in each particle and semiquantitative estimations of elemental weight percent. The review includes comparison of the particle analysis data and diagnostic findings, the particle count for the standard field analyzed, and types of particles identified. Nonneoplastic lung biopsy specimens from 25 deployed and 7 nondeployed U.S. service members were analyzed as part of the Joint Pathology Center pathologic consultations. The major exogenous particle types identified in both groups include aluminum silicates, other silicates, silica, and titanium dioxide. Endogenous particle types identified include calcium salts and iron-containing particles consistent with hemosiderin. These particles are present in deployed and nondeployed service members and are particle types commonly identified in lung biopsy specimens from urban dwelling adults. Rare particles containing other elements such as cerium and iron alloys were identified in some cases. Possible sources of these materials include diesel fuel and occupational and other environmental exposures. Scanning electron microscopy with energy dispersive X-ray particle analysis of inhaled particulates retained in lung tissue from deployed service members identifies particles commonly present in inhaled dust. In this small case series, we were not able to detect particle profiles that were common and unique to deployed patients only.

Preparation and Characterization of the Sulfur-Impregnated Natural Zeolite Clinoptilolite for Hg(II) Removal from Aqueous Solutions

Sulfur-impregnated zeolite has been obtained from the natural zeolite clinoptilolite by chemical modification with Na2S at 150 °C. The purpose of zeolite impregnation was to enhance the sorption of Hg(II) from aqueous solutions. Chemical analysis, acid and basic properties determined by Bohem’s method, chemical behavior at different pHo values, zeta potential, cation-exchange capacity (CEC), specific surface area, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), as well as thermogravimetry with derivative thermogravimetry (TG-DTG) were used for detailed comparative mineralogical and physico-chemical characterization of natural and sulfur-impregnated zeolites. Results revealed that the surface of the natural zeolite was successfully impregnated with sulfur species in the form of FeS and CaS. Chemical modification caused an increase in basicity and the net negative surface charge due to an increase in oxygen-containing functional groups as well as a decrease in specific surface area and crystallinity due to the formation of sulfur-containing clusters at the zeolite surface. The sorption of Hg(II) species onto the sulfur-impregnated zeolite was affected by the pH, solid/liquid ratio, initial Hg(II) concentration, and contact time. The optimal sorption conditions were determined as pH 2, a solid/liquid ratio of 10 g/L, and a contact time of 800 min. The maximum obtained sorption capacity of the sulfur-impregnated zeolite toward Hg(II) was 1.02 mmol/g. The sorption mechanism of Hg(II) onto the sulfur-impregnated zeolite involves electrostatic attraction, ion exchange, and surface complexation, accompanied by co-precipitation of Hg(II) in the form of HgS. It was found that sulfur-impregnation enhanced the sorption of Hg(II) by 3.6 times compared to the natural zeolite. The leaching test indicated the retention of Hg(II) in the zeolite structure over a wide pH range, making this sulfur-impregnated sorbent a promising material for the remediation of a mercury-polluted environment.

A glass workshop in ‘Aqir, Israel and a new type of compositional contamination

Materials associated with a secondary workshop of early Byzantine date (4th-5th centuries) were unearthed in excavations by the Israel Antiquities Authority in ‘Aqir, central Israel. Fragments of furnace structure, production debris and glass vessels have been analysed by scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDS) and thin-section petrography.The results suggest that the workshop melted raw glass chunks of similar composition to the primary glass made at Apollonia, Israel, to produce secondary glass products. Some glass vessels associated with the furnace are of different composition, and some of these may represent material brought in as cullet for recycling. The furnace was built with ceramic bricks comprising alluvial-type clay with inclusions of quartz sand, probably added as temper. It was fired by potash-rich fuel to approximately 1100 °C. Lime mortar was used either to cement the gaps between mudbricks or to line the furnace as a parting layer, and it has introduced a previously unrecognised type of contamination in glass of the period, mainly of Fe2O3 and CaO. The contamination may be identified in glass vessel assemblages elsewhere but is not ubiquitous. As its origin relates to the furnace structure, its occurrence may depend upon chronology or geography and further work is needed to resolve this issue.

Use of luminescent gunshot residues markers in forensic context—Part II

Gunshot residues (GSR) are important physical evidence in firearm-related crimes. Recently developed non-toxic ammunition, however, requires a new methodology for its characterization. To overcome this drawback, the introduction of noncommercial luminescent markers in ammunition was proposed. These markers, synthesized and added to the gunpowder, presented as a versatile tool for GSR analysis, since they require UV radiation alone to visualize the luminescent GSR (LGSR). This has opened up new perspectives for understanding GSR behavior at a crime scene. This work aims to expand previous studies performed with the luminescent markers in forensic contexts, exploring four different important aspects related to GSR behavior. Using LGSR amount/dispersion and a series of blind tests with marked ammunition, we tried to (1) identify the shooter position; (2) estimate the shooting distance; (3) evaluate the influence of the pistol type on the LGSR distribution on the shooter’s hands and guns; and (4) study the transference of LGSR by a chain of handshaking. For this purpose, a portable UV lamp (λ=254nm) and/or techniques such as video spectral comparator (VSC) and scanning electron microscopy with energy dispersive X-ray analysis (SEM/EDS) were used to visualize and analyze the residues. As a result, the observation of the LGSR enabled accurate determination of the shooter position and the firing distance without any chemicals. Besides, the LGSR were visualized on different kinds of pistols, regardless of firing mechanism. And finally, this study evidenced transference of residues from shaking hands with the shooter, which should be carefully considered when interpreting the results of a GSR analysis.

A novel study based on adaptive metal tolerance behavior in fungi and SEM-EDX analysis

Four fungal isolates: Simplicillium chinense (iso 9, accession no. KX425621), Penicillium simplicissimum (iso 10, KP713758), Trichoderma asperellum (iso 11, KP792512), and Coriolopsis sp. (1c3, KM403574) were subjected to a series of induced-tolerance training under high metal concentrations to determine if greater tolerance could be achieved from constant exposure to such conditions. Adaptive tolerance assay (Tolerance Index, TI) and Field-Emission Scanning Electron Microscopy with Energy Dispersive X-ray (SEM-EDX) characterized their metal tolerance. “Untrained” S. chinense, P. simplicissimum and T. asperellum showed tolerance towards 4000–4500ppm Al(III) (TI: 0.64–0.71), 1000ppm Cr(III) (0.52–0.83) and Pb(II) (0.32–0.88). With tolerance training, tolerance towards 2000–6000ppm Al(III), 500–3000ppm Pb(II) and 2000–3000ppm Cr(III) were achieved (TI: 0.01–0.82) compared to untrained cultures (0.00–0.59). In contrast, tolerance training for Coriolopsis sp. and P. simplicissimum was less successful, with TI values similar or lower than untrained cultures. SEM-EDX analysis proposed biosorption and bioaccumulation as mechanisms for metal removal. The latter was demonstrated with the removal of Cr(III) and Pb(II) by S. chinense (12.37 and 11.52mgg−1, respectively) and T. asperellum (10.44 and 7.50mgg−1). Induced-tolerance training may render benefit in the long run, but this delicate approach is suggestively species and metal dependent.

Reverse Engineering Eighth Century C.E. Window Glass Processing at Sardis, Turkey

ABSTRACTFrom the early eighth century CE Byzantine shops next to the Synagogue and Bath-Gymnasium Complex at Sardis, Turkey, were excavated from 1958 to 1969 more than 50 pounds, or about 350 panes of transparent flat glass sheets interpreted as window glass. Examination using optical microscopy showed little variation in size, shape, thickness, edge shape, tool marks, bubble and cord elongation and alignment. Microstructural and compositional variation of weathered surfaces and unweathered cross sections were studied using scanning electron microscopy with energy dispersive x-ray analysis (SEM-EDS). Differential thermal analysis (DTA) was used to determine glass transition temperature range. Three traditional window-forming methods have been described in the glass technology literature: crown, plate and cylinder. The Sardis glass is most similar to criteria expected for cylinder glass, but significant differences were documented. Consistently patterned characteristics evidence a developed technological practice. Replicative tests were conducted using various forming sequences. Wooden and ceramic two-piece molds were made to overblow one or both ends, and hot glass threads were used to thermal shock the cylinder ends and to make a vertical crack that allowed opening during a reheating and slumping operation. These reconstructed methods fit the observed microstructural and macrostructural characteristics of the glass sheets. Analysis of glass manufacturing methods in antiquity contribute to the historical knowledge of craft practices and to the interpretation of industrial debris excavated at markets and industrial workshops.

Treated and untreated rock dust: Quartz content and physical characterization

ABSTRACTRock dusting is used to prevent secondary explosions in coal mines, but inhalation of rock dusts can be hazardous if the crystalline silica (e.g., quartz) content in the respirable fraction is high. The objective of this study is to assess the quartz content and physical characteristics of four selected rock dusts, consisting of limestone or marble in both treated (such as treatment with stearic acid or stearates) and untreated forms. Four selected rock dusts (an untreated and treated limestone and an untreated and treated marble) were aerosolized in an aerosol chamber. Respirable size-selective sampling was conducted along with particle size-segregated sampling using a Micro-Orifice Uniform Deposit Impactor. Fourier Transform Infrared spectroscopy and scanning electron microscopy with energy-dispersive X-ray (SEM-EDX) analyses were used to determine quartz mass and particle morphology, respectively. Quartz percentage in the respirable dust fraction of untreated and treated forms of the limestone dust was significantly higher than in bulk samples, but since the bulk percentage was low the enrichment factor would not have resulted in any major change to conclusions regarding the contribution of respirable rock dust to the overall airborne quartz concentration. The quartz percentage in the marble dust (untreated and treated) was very low and the respirable fractions showed no enrichment. The spectra from SEM-EDX analysis for all materials were predominantly from calcium carbonate, clay, and gypsum particles. No free quartz particles were observed. The four rock dusts used in this study are representative of those presented for use in rock dusting, but the conclusions may not be applicable to all available materials.

Investigation on the effects of temperature, dissolved oxygen and water on corrosion behaviour of aluminium and copper exposed to diesel-type liquid fuels

Corrosive behaviour of RME (rapeseed methyl ester) in blends with ultra-low sulphur diesel and GTL (gas-to-liquid) fuel is investigated in this study. The tests were carried out at a wide range of blending ratios and for two of the typical metals in manufacturing of engine parts in contact with fuel (aluminium and copper). Tests were divided into two main groups: short-term at elevated temperature (80°C, 600h) and long-term (room temperature, 5760h). Effects of impurities such as presence or absence of dissolved oxygen and absorbed water were also investigated using the same test conditions. Before and after the tests metals and fuels have been investigated in many ways in order to understand the type and extend of the damage on both metal surfaces and fuel properties. Investigation of damages inflicted by fuel on metals was performed using scanning electron microscopy with energy dispersive X-ray analysis (SEM/EDS). Also nature of the oxide layer formed on the surface of the metal was studied using X-ray diffraction (XRD). Degradation of fuels as a result of exposure to metals was investigated for changes in kinematic viscosity, Total Acid Number (TAN) and any compositional changes in the fuel structure using GC–MS. Results revealed that biodiesel increases the corrosiveness of fuels exposed to both metals with more effect on copper samples, also it was found that the presence of dissolved oxygen and absorbed water is a key factor for more corrosion damage to metals. TAN value, kinematic viscosity and changes in the fuel composition all confirmed the degradation of the fuels as a result of exposure to the metals. GTL was found to be the most resistant fuel to corrosion, probably due to its chemical composition.

Aerosol Deposition and Behavior on Leaves in Cool-temperate Deciduous Forests. Part 1: A Preliminary Study of the Effect of Fog Deposition on Behavior of Particles Deposited on the Leaf Surfaces by Microscopic Observation and Leaf-washing Technique

To establish the method for investigating the behavior of aerosol particles deposited on the leaf surface against fog water under natural conditions, scanning electron microscopy with energy-dispersive X-ray (SEM-EDX) analysis and wash water analysis by ion chromatography after the washing treatment were performed using leaves of white birch collected from low part of the tree crown and the top of the tree in Sapporo City, Hokkaido, northern Japan. Each of collected leaves was divided into two parts according to the treatment performed: leaf surface (adaxial side) was 1) untreated, and 2) washed with deionized water with a pipette. In untreated samples, many particles of various shapes, including soil particles and organic debris, were deposited on the surface. Particles containing S were found on the surface of samples collected from only low part of the tree crown. After the washing treatment, SEM-EDX analysis revealed that soil particles and particles containing S had been washed off with water, although some particles such as soil particles and organic debris still remained on the leaf surface. The major anion such as <TEX>$SO{_4}^{2-}$</TEX> was detected in wash water of all samples, although the peak of S in X-ray spectra was not detected from samples collected at top of the tree. The combination of SEM-EDX analysis with wash water analysis indicated that <TEX>$SO{_4}^{2-}$</TEX> was deposited on the leaf surface in dissolved state and/or in state of submicron particles. These results suggested that fog water could remove soil particles and particles containing S and <TEX>$SO{_4}^{2-}$</TEX> from the leaf surfaces, but not all particles. There was no difference in sampling position in the tree crown. Our study suggested that combination with SEM-EDX analysis and wash water analysis would be effective for investigation of the behavior of particles on the leaf surface against fog water.

Corrosion effects of RME in blends with ULSD on aluminium and copper

The present study concerns corrosion of aluminium and copper in ultra low sulphur diesel fuel and its blends with rapeseed methyl ester. Tests were carried out at wide ranging contents of rapeseed methyl ester (0%, 50%, 75% and 100%) at 80°C for 600h. At the end of the immersion test a comparison was performed by weight loss corrosion rate measurement and by analysis of damages of metal surfaces. Analysis of fuels was performed by using total acid number measurement and by gas chromatography–mass spectrometry to investigate the acid concentration and change of fuel composition respectively. Damages afflicted on metal surfaces were examined by scanning electron microscopy with energy dispersive X-ray analysis (SEM/EDS). Results showed that increasing the biodiesel content enhanced the corrosiveness of blend to both metals; this was confirmed by analyses of fuel properties and damage on metal surfaces exposed to fuels. Also it was found that copper was more vulnerable to attack compared with aluminium for all blends.

Catalysts based on clay and iron oxide for oxidation of toluene

Two samples of heterogeneous catalysts were prepared by impregnating a raw-clay, a montmorillonite-rich material, with iron oxides, in order to be used in oxidative reactions of toluene. The starting clay-sample was collected from a pedon in the region of San Juan, Argentina. All catalysts were characterized with X-ray powder diffraction (XRD), infrared spectroscopy, temperature programmed reduction (TPR), scanning electron microscopy with energy dispersive X-ray analysis (SEM/EDS), and specific surface area measurements. After impregnating the raw clay material with iron oxides, there was a collapse of basal plane spacing and an increase in surface area, from 17 to 62m2g−1 of montmorillonite. The TPR, EDS, and XRD results evidenced that the dispersion of iron-containing species depended on how the impregnation was made. The catalyst with higher exposure to iron oxides on sample preparation presented a higher catalytic activity on toluene oxidation.

Characterization of anatomy, ultrastructure and lignin microdistribution in Forsythia suspensa

Forsythia suspensa, as a traditional Chinese medicinal herb, has been studied extensively. In this work, morphological and anatomical features of F. suspensa stem were examined by light microscopy (LM) and scanning electron microscopy (SEM). The results showed that the slenderness and Runkel ratio is 51 and 0.67, respectively. Anatomical observations indicated that F. suspensa is diffuse-porous wood. Helical thickenings and alternate intervessel pits are present on vessel cell wall. Transmission electron microscopy (TEM) images exhibited that the fiber cell wall is typically differentiated into three layers: middle lamella (ML), primary wall (P) and secondary wall (S1, S2 and S3), and the staining intensities represent differing lignin concentrations. Also, the confocal laser scanning microscopy (CLSM) and scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDXA) were used to investigate the lignin distribution in cell wall qualitatively and semi-quantitatively. Confocal images (488nm) revealed a high level of lignin autofluorescence in the cell corner middle lamella (CCML), with lower levels of fluorescence in the compound middle lamella (CML) and S2 region. The results from SEM-EDXA demonstrated that lignin concentration ratio in different regions of fiber wall is 1.3 (CCML):1.1 (CML):1 (S2).

Comparative corrosive characteristics of petroleum diesel and palm biodiesel for automotive materials

Corrosive characteristics of biodiesel are important for long term durability of engine parts. The present study aims to compare the corrosion behavior of aluminum, copper and stainless steel in both petroleum diesel and palm biodiesel. Immersion tests in biodiesel (B100) and diesel (B0) were carried out at 80 °C for 1200 h. At the end of the test, corrosion characteristic was investigated by weight loss measurements and changes on the exposed metal surface. Surface morphology was examined by optical microscope and scanning electron microscopy with energy dispersive X-ray analysis (SEM/EDS). Fuels were analyzed by using TAN analyzer, FTIR, GCMS and ICP in order to investigate the acid concentration, oxidation level with water content, compositional characteristics and presence of metal species respectively. Results show that the extent of corrosion and change in fuel properties upon exposure to metals are more in biodiesel than that in diesel. Copper and aluminum were susceptible to attack by biodiesel whereas stainless steel was not.

The 17th Dynasty gold necklace from Qurneh, Egypt

In 1908, the archaeologist Flinders Petrie discovered a rich intact burial of an adult and child at Qurneh, near Luxor. Stylistically, the burial has been dated to the late 17th Dynasty, in the 16th century BC. The complete burial group came to Edinburgh in 1909. A recent examination of the rings of the necklace found with the adult burial is presented as part of a wider study of the mummy collections of the National Museums Scotland (NMS). The necklace shows sophisticated workmanship, with 1,699 rings threaded onto four strands, the rings having uniform diameter and thickness, and very few of them showing any visible joints. The necklace rings have been examined by Optical Microscopy, X-radiography, Scanning Electron Microscopy with Energy Dispersive X-ray analysis (SEM-EDS), air-path X-ray Fluorescence (XRF), and proton induced X-ray analysis (micro-PIXE). We summarise these findings and propose the method of manufacture. We also describe an experimental attempt to make joint-less rings in order to compare them with the originals.