SEM Examination Research Articles

Magnetite-silica core-shell nanostructures: Application for photodynamic therapy

Magnetite nanoparticles have been synthesized with chemical co-precipitation. The surface of magnetite nanoparticles was coated with an inorganic silica layer by hydrolyzing and condensing tetraethyl orthosilicate. An XRD investigation supports the cubic inverse spinel structure of Fe3O4 nanoparticles. The average crystallite size of the magnetite nanoparticles produced by the peak broadening was 13 nm. The UV-visible spectrum of methylene blue-loaded magnetite-silica nanoparticles shows a strong hump at 657 nm. According to TEM examination, the nanoparticles are polydisperse and almost spherical in form.The average size of the nanoparticles is 14.39 nm plus 1.66 nm, and they have a polydispersity index of 0.12%.The size and shape of the core-shell particles are not uniform, according to a SEM examination. There is no distinguishing morphology in any sample.The magnetic results depicts the superparamagnetic behaviour of nanoparticlesmakes them suitable for photodynamic therapy.

Structure and Deformation Behavior of Polyphenylene Sulfide-Based Laminates Reinforced with Carbon Fiber Tapes Activated by Cold Atmospheric Plasma.

Low-temperature plasma treatment with atmospheric discharge with runaway electrons (DRE) was shown to be an efficient way to activate carbon fiber's (CF) surface and subsequently increase its interlayer shear strength (ILSS) values. It was demonstrated that an acceptable ILSS level was achieved after a DRE plasma treatment duration of 15 min. The treatment of CFs resulted in their surface roughness being increased and their functional groups grafting. The XPS data showed a change in the chemical composition and the formation of reactive oxygen-containing groups. SEM examinations of the PPS/CF laminates clearly demonstrated a difference in adhesive interaction at the PPS/CF interface. After the DRE plasma treatment, CFs were better wetted with the polymer, and the samples cohesively fractured predominantly through the matrix, but not along the PPS/CF interface, as was observed for the sample reinforced with the untreated CFs. The computer simulation results showed that raising the adhesive strength enhanced the ILSS values, but reduced resistance to transverse cracking under the loading pin. In general, higher flexural strength of the PPS/CF laminates was achieved with a greater interlayer adhesion level, which was consistent with the obtained experimental data.

Topographical Analysis of Human Enamel after Phosphoric Acid Etching and Er,Cr:YSGG Laser Irradiation.

Introduction: Dental hard and soft tissues have been successfully removed by using the Er,Cr:YSGG laser, but there is a controversy about using lasers over conventional tooth surface preparation for bonding aesthetic restoration. Surface roughness and wettability in response to Er,Cr:YSGG laser irradiation are essential properties for restoration longevity. Methods: Fifty-one intact human premolars removed in orthodontic treatment were included in this study and divided into three groups (n=17). The first group (G1) was the control without surface treatment, (G2) was treated with 37% phosphoric acid for 15 seconds, and (G3) was treated with the Er,Cr:YSGG laser using the following parameters: 2 W or 3 W at 20 Hz, 10% air and water ratio using the MZ6 laser tip. The standardization of laser irradiation was accomplished by a computerized numerical control unit. The surface of the samples was evaluated by using a light microscope, profilometer, atomic force microscopy (AFM), SEM, and wettability tests. Results: The SEM examination revealed that the lased enamel surface was clean, irregular, and devoid of a smear layer, while the acid etch surface was relatively smooth and covered with a smear layer. The surface roughness of the lased enamel surface was significantly higher than that of other groups, according to the results of the profilometer as well as the AFM tests. The wettability test showed that the lased enamel surface recorded a significant reduction in the contact angle in comparison to the other groups. Conclusion: It can be concluded that the Er,Cr:YSGG laser can be used as an alternative and safe method to the acid-etching technique for surface treatment.

Hygrothermal effects on fatigue delamination behavior in composite laminates

Fatigue delamination growth (FDG) is an important failure in composite structures during their long-term operations. Hygrothermal aging can have significant effects on interlaminar resistance. It is therefore really necessary to explore FDG behavior in composite laminates with hygrothermal aging. Dynamic mechanical thermal analysis (DMTA), mode I FDG experiments and fractographic examinations were conducted to fully investigate hygrothermal aging effects and the corresponding mechanisms on FDG behavior. The DMTA results indicated that environmental aging can induce obvious Tg decrease. Mode I experimental fatigue data interpreted via different Paris-type correlations demonstrated that: Bridging has obvious retardation effects on FDG behavior via the Paris interpretations; The modified Paris relation can well characterize the intrinsic FDG behavior around the crack front; The use of the two-parameter Paris-type relation can appropriately account for R-ratio effects, contributing to a master resistance curve in determining mode I FDG behavior. According to these interpretations, it can be concluded that hygrothermal aging can have adverse effects on mode I FDG behavior. SEM examinations demonstrated that moisture absorption can cause fibre/matrix debonding and resin matrix pores/voids in the composite. However, no obvious difference in damage mechanisms was identified in mode I fatigue delamination for composite with/without environmental conditioning. Both fibre/matrix debonding and matrix brittle fracture were identified on fatigue fracture surfaces. Accordingly, it was concluded that fibre/matrix interface and matrix degradation induced by water absorption were the main reasons for a faster mode I fatigue crack growth in environmental aged composite.

Variability of sedimentary pyrite δ34S records: A case study of slope shale of the Green Point Formation in western Newfoundland, Canada

The Green Point Formation in western Newfoundland, GSSP of the Cambrian-Ordovician (Є-O) boundary, is dominated by slope rhythmites of alternating lime mudstone and shale interbeds. This formation was deposited in a semi-restricted basin with varying connectivity to the open ocean. In the current study, we investigate textures and bulk δ34S signatures of pyrite (δ34Spy) in the shale to better understand factors influencing the sedimentary δ34Spy fluctuation. Petrographic and SEM examinations reveal two major types of pyrite: (1) framboidal pyrite and (2) anhedral to euhedral pyrite. The latter is further categorized into two subtypes: type 2a anhedral to subhedral pyrite characterized by relict framboidal textures and larger sizes (∼10 to 300 μm), and type 2b smaller (typically <10 μm) subhedral to euhedral pyrite. Type 1 pyrite was precipitated near the sediment-water interface (SWI), whereas type 2b pyrite was formed in sediments below the SWI with limited access to the overlying seawater sulfate. Type 2a pyrite was evolved from framboids during early and burial diagenesis. The bulk δ34Spy values, marked by a significant scatter (1σ =10.62‰), range broadly from −17.6 to +22.4‰ (VCDT) and exhibit a pronounced positive excursion of ∼20‰ near the Є-O boundary. The abundance of type 2b pyrite generally mimics the changes in δ34Spy, suggesting that the substantial δ34Spy dispersion could be partially attributed to differing proportions of type 2b pyrite within the samples. Moreover, notable negative correlations exist between the δ34Spy values and the abundances of Al, Th, ∑REE, and Fe, indicating that riverine fluxes might have influenced the Δ34Sseawater – pyrite by modulating the regional seawater sulfate and iron reservoir sizes. Therefore, rather than being indicative of oceanic redox oscillations, the positive δ34Spy excursion of ∼20‰ of this interval was probably driven by decreased sulfate and iron levels in the local waterbody. The decline in terrestrial input during this δ34Spy shift might have also contributed to a negative δ13Ccarb excursion by reducing nutrient supply and inhibiting primary productivity. Collectively, the bulk sedimentary δ34Spy variability recorded by the Green Point shale may be attributed to a combination of changes in regional terrigenous input and varying amounts of pyrite formed at different diagenetic stages within the samples. The general opposing trends between the δ34Spy signals and the abundances of Al, Th, ∑REE, and Fe, however, imply that fluctuations in riverine influxes might exert a stronger influence on the major δ34Spy trend. These findings suggest that bulk sedimentary δ34Spy variations may not be reliable evidence for perturbations of the global sulfur cycle.

Antibacterial Activity of Green Synthesized Eugenia jambolana Seeds Extract Mediated Silver Nanoparticles

The present study uses silver nanoparticles that are biosynthesized from Eugenia jambolana aqueous silver nitrate solution jambolana fresh seed extracts were combined with silver nitrate (AgNO3) to form the silver nanoparticle. UV-Vis Spectrophotometry, XRD, SEM, and FTIR were used to characterise the synthesised silver nanoparticles. It was established that nanoparticles had formed in the sample by SEM examination, which revealed that they had a spherical shape. Nanoparticles from seed extracts showed more antibacterial activity on Pseudomonas aeruginosa followed by Bacillus subtilis, Vibrio cholerae, and Staphylococcus aureus. This study makes evidence that seed extracts of Eugenia jambolana act as an excellent capping agent for the formation of silver nanoparticles and show immense Pharmacological activities. Hence, these AgNPs can be used as an antimicrobial agent in treating many medical complications. In this present study, the antibacterial activity of green synthesized silver nanoparticles from Eugenia jambolana seeds shows the zone of inhibition against all four pathogens.

Corrosion inhibition of pure iron by Eurohypnum leptothallum extract in 0.5 mol L−1 H2SO4: an experimental and GC-MS based study

Abstract In this work, the functional groups of Eurohypnum leptothallum extract (ELE) were extracted by aqueous immersion and identified by FTIR. The corrosion inhibitory effect of ELE as a natural plant corrosion inhibitor on pure iron in 0.5 mol L−1 H2SO4 solution was investigated by test methods such as the weight loss method, electrochemical behaviour and detection of metal surface topography. The results show that ELE has a positive inhibitory effect on the corrosion behaviour of pure iron in 0.5 mol L−1 H2SO4 solution, and the higher the concentration of ELE, the greater the corrosion inhibitory effect. It can still reach 83.97 % at high temperatures. The results of SEM examination and contact angle measurements show that the corrosion degree of the metal decreases significantly after the additon of ELE and that the hydrophobicity of the metal surface increases. The adsorption of ELE on the surface of pure iron tends to isothermal Langmuir adsorption and, as a mixed corrosion inhibitor, the charge transfer resistance of the system increases significantly and the capacitance value of the electrical double layer decreases significantly.

Green Synthesis of Silver Nanoparticles from Phyllanthus emblica (Indian Gooseberry) for Potent Antimicrobial Efficacy

Nowadays cost-effective and environmentally friendly technologies for nanomaterial synthesis have gained attention in the biosynthesis of nanoparticles. The present study is focused on synthesizing silver nanoparticles using Phyllanthus emblica for a green approach. UV-Vis Spectrophotometry, XRD, SEM, and FTIR were used to characterise the synthesised silver nanoparticles. It was determined that spherical shaped nanoparticles by SEM examination, which revealed that the average particle size was 20 nm. Antibacterial activity of AgNPs analyzed with the help of Staphylococcus aureus, Vibrio cholerae, Pseudomonas auriginosa, and Bacillus subtilis bacteria, and the result shows that a higher concentration of AgNPs is increasing as well as a zone of inhibition increased.

The mosaic tesserae in the industrial Byzantine wine press, Yavne, Israel: A natural unusually hard chalk or a chemically transformed chalk?

Many of the surfaces of a large industrial scale wine press from the Byzantine period in Yavne, Israel, are covered in mosaic tesserae. These surfaces are part of the grape presses, storage pools, fermentation pools and also the walkways between these structures. The calcitic tesserae resemble limestone in color, texture and fracture properties. We were therefore surprised to discover that they are more disordered at the atomic level than consolidated limestone and in fact they are as disordered as porous and friable chalk. In addition SEM examination of fracture surfaces reveals abundant nannofossils, mostly coccoliths and foraminifera; properties that are also reminiscent of chalk. The nanofossil identifications shows that the tesserae are from the Middle Eocene, and this includes the chalky Maresha Formation that outcrops about 15kms from the site. SEM examination of polished surfaces shows that the larger pores of tesserae are lined with euhedral calcite crystals. Vickers hardness measurements show that the tesserae are much harder than chalk, and are comparable to limestone. There are two scenarios for explaining these seemingly contradictory observations. One scenario is that a chalky limestone geological formation with all these properties exists somewhere in the Mediterranean region and is the source of the raw material for the tesserae. The second scenario is that the Byzantine constructors of the wine press transformed a chalk into a harder and more consolidated material. Chalk transformation processes akin to plaster formation can be excluded based on the analyses of the stable carbon isotopic compositions of the tesserae, as well as their 14C concentrations. A chemical transformation using a weak acid that would only affect the calcite in the vicinity of the accessible pores, and leave the bulk of the chalk and its microfossils in a good state of preservation, is conceivable. In fact a by-product of producing wine is vinegar and the acetic acid of the vinegar could conceivably have been used for this purpose. If indeed a chemical transformation of soft chalk into a hard durable material was used, this would represent a “lost” technology that might even be useful in present times.

Exploring the antibacterial and antibiofilm potential of copper oxide nanoparticles biosynthesized using Centratherum punctatum leaf extract

This manuscript focuses on the eco-friendly synthesis of copper oxide nanoparticles (CuO NPs) using Centratherum punctatum leaf extract. FTIR analysis confirmed the presence of functional groups, while UV–vis spectral analysis exhibited absorbance peak at 224 nm. XRD analysis provided insights into the particle's crystallinity, revealing, crystal size in the range of 20–30 nm. SEM examination revealed the presence of spherical and hemispherical aggregated particles. The CuO NPs demonstrated potent antimicrobial activity and effectively inhibited biofilm formation by Pseudomonas aeruginosa. The environmentally friendly synthesis and promising antimicrobial and antibiofilm activities of CuO NPs make them noteworthy candidates for further exploration.

Characterization of aged Li4SiO4 pebbles performance

Many studies and research have been carried out in the recent years to identify which breeder material and (in which) form, solid or liquid, are most suitable to be used in the Breeder Blanket (BB) modules. Nonetheless, the choice of a stable material, with high thermal conductivity and melting point remains unsolved and becomes even more complex when durability is considered. The breeder material must guarantee that the thermo-mechanical properties change as little as possible under environmental and operating conditions. The aim of this study is to investigate the ageing effects on the mechanical behaviour of lithium orthosilicate (Li4SiO4) in form of pebbles. The pebbles had been produced at the University of Pisa at room temperature by a hydrolytic sol-gel supported drip casting method and subsequently stored for 4 years in an environment simulating normal storage (i.e., standard condition). These pebbles of about 1.2–1.4 mm diameter have been subjected to uniaxial compression tests, without radial constraints, and SEM analysis. The results obtained were compared to those of non-aged pebbles to highlight the degradation caused by the ageing. SEM examination of aged pebbles showed increased porosity and a pebble surface that was not entirely homogeneous and uniform. This affected the crack shapes on the contact surface and the crushing load.

Synergizing electrical, mechanical, and radiation shielding properties of dendritic copper filled epoxy polymer composites

The study examined the properties of epoxy composites with dendritic copper (Cu) particles through various tests, including FTIR, DSC, TGA, electrical conductivity, and mechanical tests. The addition of Cu particles to the composites improved their electrical conductivity and mechanical properties, particularly tensile strength and flexural modulus. The Tg temperature of the composites could be adjusted by varying the Cu particle ratio. Notably, in the study, we prepared composites with varying Cu particle concentrations, specifically at ratios of 1%, 2%, 3%, 4%, 5%, and 6%, and observed distinct effects on the properties of the epoxy-Cu composites. Although there was no chemical bonding between the epoxy and Cu particles, the Cu additive acted as a pinning agent, restricting the movement of the polymer chains. This suggests that incorporating small amounts of Cu into epoxy composites can enhance their properties, making them suitable for applications in the electrical and electronics industry. Additionally, we evaluated the shielding properties of selected epoxy-based composites incorporating copper powder against gamma radiation with energies of 59.5 keV, 661.6 keV, and 1332.5 keV, and also investigated the composites' ability to attenuate gamma rays, recommending specific composites (ECU6, ECU1, and ECU2) for different energy levels of gamma rays. SEM examinations showed that the addition of Cu particles significantly altered the microstructure and mechanical properties of the composites, resulting in an irregular and rough fracture surface and decreased structural integrity.

Investigating and modelling of highly stressed firearms parts

Recently, there have been too many Pulemyot Kalashnikova Modernizirovannyi (PKM) machine gun bolts that have failed during the firing process. Due to the increased temperature, higher propellant gas pressure, and thermal accumulation, the bolt body is exposed to sever circumstances for ablating, corroding, and erosion. In this paper, the reasons of failure of PKM bolts during firing were evaluated first based on metallurgical experiments. Then, analysing the failure is done by create an accurate finite element model of the bolt body, calculating the cyclic fatigue life and safety factor, determining the causes of failure and be verified showing that failure locations are exactly as shown in the photographic record. the original bolt dimensions were measured using laser scanning, and a CAD model of the bolt was created. Photographic records, visual inspection, chemical analysis, SEM, and hardness measurements, all these metallurgical experiments have been done. The stress distributions and fatigue behavior of the failed bolt are both determined using the Finite Element Method (FEM). This study suggests that fatigue played a role in bolt failure. Furthermore, SEM examinations reveal that the materials contain dimple fractures. The bolt’s fatigue life was decreased by these dimpled fractures.

The anticancer and antibacterial potential of bioactive secondary metabolites derived From bacterial endophytes in association with Artemisia absinthium

The continuous search for secondary metabolites in microorganisms isolated from untapped reservoirs is an effective prospective approach to drug discovery. In this study, an in-depth analysis was conducted to investigate the diversity of culturable bacterial endophytes present in the medicinal plant A. absinthium, as well as the antibacterial and anticancer potential of their bioactive secondary metabolites. The endophytic bacteria recovered from A. absinthium, were characterized via the implementation of suitable biochemical and molecular analyses. Agar well diffusion and broth microdilution were used to screen antibacterial activity. SEM was performed to assess the impact of the extracted metabolite on MRSA strain cell morphology. Apoptosis and cytotoxicity assays were used to evaluate anticancer activity against MCF7 and A549. The FTIR, GC–MS were used to detect bioactive compounds in the active solvent fraction. Of the various endophytic bacteria studied, P. aeruginosa SD01 showed discernible activity against both bacterial pathogens and malignancies. The crude ethyl acetate extract of P. aeruginosa SD01 showed MICs of 32 and 128 µg/mL for S. aureus and MRSA, respectively. SEM examination demonstrated MRSA bacterial cell lysis, hole development, and intracellular leaking. This study revealed that the crude bioactive secondary metabolite SD01 has potent anticancer activity. In this study, 2-aminoacetophenone, 1,2-apyrazine-1,4-dione, phenazine and 2-phenyl-4-cyanopyridine were the major bioactive secondary metabolites. In conclusion, our findings indicate that the bacteria recovered from A. absinthium plants and in particular, P. aeruginosa SD01 is a remarkable source of untapped therapeutic, i.e., antimicrobial and anticancer compounds.

Strain hardening composite made of LC3 binder and mineral impregnated carbon yarn: effect of crystalline admixture on mechanical characteristics and microstructure

The addition of crystalline admixtures in the cementitious composite is instrumental in imparting water tightness, enhancing strength, and achieving self-healing abilities in various construction applications. In this work, the viability of using crystalline admixtures in heat-cured strain-hardening cementitious composites (SHCC) and their impact on specimens subjected to alkaline and aqueous environments are examined. In SHCC, lime stone-calcined clay cement (LC3) is used in the matrix and mineral-impregnated carbon yarns are used as reinforcement. The usefulness of heat curing for SHCC to water curing is initially assessed by analyzing the mechanical characteristics and connecting them to the microstructural components by SEM examination. Investigations reveal that the crystalline admixture increases compressive strength in water- and heat-cured specimens by 30–37%, respectively. Subsequently, a uniaxial tensile test is conducted on heat-cured SHCC specimens and on pre-damaged ones that are submerged in tap water and also in alkaline water. The impact of crystalline admixture on the SHCC's tensile response was examined, and the results were correlated with SEM examination. The maximal stress is increased by approximately 14% and 26% when pre-damaged SHCC specimens with crystalline admixture are submerged in water and an alkaline environment, respectively.

Enhancing the mechanical performance of plastering mortars with low levels of multilayer graphene and their chemical, structural, and microstructural characteristics

The present work investigated the impact of low levels of graphene incorporation into plastering mortars. The presence of graphene proved beneficial in various properties, as it can increase the area and specific surface of composites and accelerate the hydration process, facilitating the formation of hydrated calcium silicate gels. Specifically, adding 0.06% graphene led to a 15% increase in axial compression strength and an 18% improvement in flexural tensile strength. Low levels of graphene correlate with increased hydration, resulting in better expansion and shrinkage performance. SEM examinations demonstrated that reference mortar showed numerous microcracks that affected their mechanical behavior. In addition, plastering mortars containing 0.03% and 0.06% graphene show smaller pore sizes and higher crystal densities, which improved cohesion and void filling. However, increasing graphene concentrations beyond 1%, led to particle dispersion. This dispersion did not enhance the binder's hydration process, impeding chemical interactions among the cement gel crystals. In summary, this work highlights the potential benefits of controlled graphene incorporation for optimizing plastering mortar properties, emphasizing the importance of finding the right balance to harness its advantages without compromising performance.

An Experimental Study ofthe Physio-Mechanicaland Microstructural Performances of Escherichia Coli Bacteria-Based Bio-Concrete

A balanced mixture of cement, sand, stone or brick chips, and water is carefully allowed to form concrete, a man-made building material. These elements can be adjusted appropriately to produce concrete with a variety of qualities. Although concrete may endure compressive forces, like natural stone, tensile forces can cause it to crack. As a result, crack formation is afrequentoccurrence in concrete, allowing various foreign chemicals and water to enter the structures and shortening their life span. The likelihood of cracking grows with time due to variations in humidity and temperature. It can be exceedingly expensive to maintain or repair concrete construction items. The use of bio-concrete for the construction of durable structures has shown to be quite advantageous in this perspective. It is beneficial for improving the properties of concrete as well as lowering maintenance costs. In this investigation, concrete samples measuring 100×100×100 mm weremade and periodically tested for compressive and split tensile strength testing. Following a 28-day curing period, the concrete treated with Escherichia coli bacteria had compressive and split tensile strengths that were 10% and 23% higher than identical bacteria-free. The non-destructive test on cylindrical samples was then conducted to evaluate the material qualities. The mortar samples of crystalline structures were also validated by SEM examination. In order to properly and reliably anticipate the strength of concrete, the RSM model was also formulated.

Effect of fiber surface treatment on mechanical, interfacial, and moisture absorption properties of cattail fiber‐reinforced composites

AbstractSurface treatment of cattail, a lignocellulosic renewable fiber, was investigated to determine the conditions that would reduce moisture absorption while maximizing the properties of cattail fiber‐reinforced unsaturated polyester composites. Surface modification of cattail fiber was studied by treating them with 2.5, 5, and 10% of 1,6‐diisocyanatohexane (DIH) and 2‐hydroxyethyl acrylate (HEA) for three different immersion times (10, 20, and 30 min). DIH‐HEA treated fibers were preformed into a non‐woven mat and impregnated with unsaturated polyester resin to manufacture composite. The existence of covalent bonds on the treated fibers via NH and CN groups was confirmed by FTIR spectroscopy. The 10% DIH‐HEA resulted in the best results; while the mean diameter of the treated fiber decreased by ~37%, the modulus and the strength of it increased by ~267 and ~151%, respectively. Equilibrium moisture regain of the treated fibers and their composites decreased by ~43% and ~40%, respectively. The tensile modulus of the composites increased by ~171%. Enhancement in tensile strength is observed but could not be quantified due to the difference in Vf and scatter in the data. SEM examination confirmed the enhancement in fiber–matrix bonding due to surface treatment.

Ovicidal and Pediculicidal Activity of Indigofera suffruticosa Mill. Leaf Oil on Pediculus humanus capitis Egg to Adult Stages.

Pediculosis capitis, commonly known as head lice infestation, represents a significant health 26 problem for school children worldwide. Repeated and long-term usages of highly toxic pediculicides have resulted in the development of increased levels of resistance and do not kill louse eggs. Alternative pediculicides, such as herbal products, have recently been proposed for the treatment of head lice infestation, thereby decreasing toxicity. This study analyzed the chemical composition of I. suffruticosa leaf extracts using GC-MS and evaluated the effects of Indigofera suffruticosa Mill. (I. suffruticosa) leaf extract on the mortality of head lice and their eggs. The major five components of the tested oils identified were as follows: n-hexadecanoic acid, hexadecanoic acid, ethyl ester, oleic acid, (E)-9-octadecenoic acid ethyl ester, and linoleic acid ethyl ester. The effective pediculicide of the I. suffruticosa leaf extracts affected head lice in all stages (egg, nymph, and adults). The concentrations of I. suffruticosa leaf extracts at 500mg/mL produced the highest effective ovicidal on egg with 96.6% unhatching and pediculicide on nymphs and adults with 96.7 ± 5.7% and 86.7 ± 5.7% mortality, respectively, at 60min (LT50 value < 10min). The analysis of the external structure of the adult-stage head lice by SEM examination revealed that dead lice exposed to I. suffruticosa leaf extract displayed damage to the outer smooth architecture and obstructed the respiratory spiracles. We may conclude that the application of I. suffruticosa leaf extract produces an effective herbal pediculicide capable of affecting all stages of head lice.

Roman wall paintings from the Roman Forum district of Carthago Nova: Characterisation of mortars and pigments

This paper aims to study the construction technique and characterisation of original mortars and wall paintings at the Roman Forum district of Carthago Nova (Spain). A multi-analytical approach was conducted on original fragments using Optical Microscopy (OM), Field Emission Scanning Electron Microscopy (FESEM), colour tests (CIE L*a*b*) and contact angle measurements. Besides, the chemical composition was studied by X-fluorescence (XRF), Thermogravimetry (TG), X-ray diffraction (XRD) and Infrared spectroscopy using attenuated total reflectance (ATR-FTIR). The mortars showed a multi-layered pattern consisting of three distinguishable layers that were decorated with low-thickness coatings. The top layer composition was eminently calcitic, while the central and bottom layers were probably elaborated with pozzolanic materials. It is worth noting that unusual minerals as cerussite (PbCO3) were identified in some layers, and probably associated to subsequent activities carried out in the site after Roman times. The top coating was made of hematite (Fe2O3) for red decoration, whereas graphite (C) and hydroxyapatite (Ca5(PO4)3(OH)) were identified in black coatings, which suggests the use of animal bones in the production of black pigments. In addition, the outer surface of some fragments was most likely coated with organic substances to enhance colour and durability. Finally, SEM examination and EDX analyses also confirmed some of the above findings and the existence of NaCl surface crusts due to natural weathering.