Characterization of medieval plasters as substrates for mural paintings in Estonia

The effect of investment material type on the contamination zone and mechanical properties of commercially pure titanium castings

The Piper betle L. leaves and their significance were described in various ayurvedic studies of India and China for its diverse use in cultural practices and treatment of various health disorders. The leaves of P. betle were used as post-meal mouth freshener in India for centuries. However, it offers economic benefits to farmers of Coastal India at large. Betel leaves cultivated agricultural soils play a significant role for their mineralogical composition. So, this present study aimed to find out the soil physicochemical characteristics and C/N contents of Betel vineyards of coastal Odisha. The soil and water samples were collected from local varieties of P. betle L. cultivated vineyards of Balasore, Ganjam, and Puri districts of Odisha and investigated their mineralogical composition. The soil mineralogy plays crucial role to understand the soil–plant relations. Coastal soil samples also contain the most prized mineral aggregations from economical perspectives. The mineralogical composition involves chemical composition, essential elemental composition, and surface morphology. The mineralogical and elemental composition of soil samples were carried out by using various techniques like Fourier transform infrared spectroscopy, X-ray diffraction (XRD) and energy-dispersive X-ray fluorescence, scanning electron microscopy attached with energy-dispersive X-ray system. CHNS analyzer for quantification of hydrogen, nitrogen, carbon, and sulfur content. H2O2 (30%)-treated soil is employed to eliminate the organic carbon from mass soil samples. The scanning electron microscopy analysis revealed the presence of heterogeneity shape and size of surface soils of both treated and untreated soils. For estimation of total organic carbon (TOC), inorganic carbon, total nitrogen, and total carbon, water samples were analyzed through TOC analyzer. Percentage variation arises in GAN and PUR sites soil due to more assumption of organic matter from clay soils in comparison with sandy soils of BAL. The spectra of FTIR point out Kaolinite and Quartz as the key components and others are minor components. The common minerals like quartz, hematite, kaolinite, montmorillonite, calcite, organic matter and illite in diverse compositions are recognized. Further, the presence of these above minerals was confirmed by the XRD analysis. Morphological analysis of kaolinite indicated euhedral, hexagonal, and pseudo-hexagonal-shaped plates. The mineralogical data revealed the relative abundance of phosphorus and nitrogen was less in all soils. Depletion of P and N may be resulted due to introduction of fresh plowed soil from grazed pastoral land. The present research uncovers that soils requires adequate input of additional compost, manures, and fertilizers for maximal vegetative growth and economic yield as well. As P. betle species is very precious medicinal plant, and this research suggested not to use contaminated water for betel cultivation. Our results also helpful for the improvement in soil management in the vineyards to determining the mineral nutrients that affect plant growth and development.

Micro-structural, petro-graphical and mechanical studies of schist rocks under the freezing-thawing cycles

In this work, we have focused the effect of substrate on electrochemically grown copper oxide and copper sulfide thin films. The prepared films have been subjected to X-ray diffraction, scanning electron microscopy, Energy dispersive X-ray analysis, UV–Visible spectroscopic techniques for the determination crystalline nature, morphology, composition and optical properties. X-ray diffraction results indicated the deposited films exhibited cubic structure with most reflection along (110), (220) planes for copper oxide and copper sulfide. Scanning electron microscopy along with energy dispersive analysis by X-rays showed that films with uniform morphology and nearly stoichiometry have been obtained for film obtained on SnO2 substrate. Optical absorption and transmittance measurements showed that the deposited films exhibited band gap value of 2.28 and 2.45 eV for copper oxide and copper sulfide.

Matrix permeability could be a key factor controlling shale gas production from matrix to micro fractures and further to hydraulic fractures in Chinese shales due to the low porosity and permeability, affected by its unique geochemistry and geology settings including the Total Organic Carbon (TOC) content, mineral compositions, pore structure, and deposition environment. This paper aims to study the controlling factors of the matrix permeability in the continental shale formation, Ordos, China, through modified laboratory measurement mothod. In this work, nine shale samples were collected from three wells in Chang 7 member, Yanchang continental formation, Ordos Basin, China, crushed at in-situ water saturation and sieved to certain size (20/40 mesh). Matrix permeability of these samples was measured with modified Pressure-decay method and compard with the results with Pulse-decay method. The reasons for the discrepancy of these results with different methods were analysed. Moreover, the effects of geochemistry and geology factors on matrix permeability were investigated by grouping these crushed samples according to the variation of TOC, mineral compositions and deposition depth. The relationships between shale matrix permeability and TOC as well as depth were established respectively. Furthermore, the effects of other factors such as mineralogical compositions and pore structure parameters were studied through the Scanning Electron Microscope (SEM) and X-ray diffraction (XRD) analysis. The results show that the shale matrix permeability measured by the Pulse-decay method is generally up to two orders of magnitude higher than that by the Pressure-decay method due to the presence of the natural or artificial micro fractures. In addition, the geochemistry and geology parameters including the TOC, mineral compositions, pore structure and deposition environment have significant effects on the shale matrix permeability. Matrix permeability in Yanchang shale formation is strongly related to TOC and the mineral compositionand even at the similar depth, porosity and matrix permeability are different due to the variation of TOC as a result of geological heterogeanity. TOC in Yanchang formation varies considerably in the range of 1.8 wt % to over 11 wt %, resulting in significant changes in matrix permeability ranging from 0.02 nD to 10 nD, resulting from the influence of the organic matter and clay minerals on total pore volume based on the result of SEM and XRD analysis. The accurate measurement of matrix permeability is important for computer simulation modeling of long term shale gas production.

Investigation of the effect of addition/replacement of bioactive glass to hydraulic calcium silicate cement.

Utilizing Malaysian bamboo for use in thermoplastic composites

The effects of ceria on the mechanical properties and thermal shock resistance of thermal sprayed NiAl intermetallic coatings

Calcium phosphate cement (CPC) sets to form microporous solid hydroxyapatite with excellent osteoconductivity, but its brittleness and low strength prohibit use in stress-bearing locations. The aim of this study was to incorporate prehardened CPC particles and ceramic whiskers in a resin matrix to improve the strength and fracture resistance, and to investigate the effects of key microstructural variables on composite mechanical properties. Two types of whiskers were used: silicon nitride, and silicon carbide. The whiskers were surface-treated by fusing with silica and by silanization. The CPC particle fillers were either silanized or not silanized. Seven mass ratios of whisker-silica/CPC were mixed: 0:1 (no whisker-silica), 1:5, 1:2, 1:1, 2:1, 5:1, and 1:0 (no CPC). Each powder was blended with a bisphenol-a-glycidyl methacrylate-based resin to harden in 2 x 2 x 25 mm molds by two-part chemical curing. The specimens were tested in three-point flexure to measure strength, work-of-fracture (toughness), and elastic modulus. Two-way analysis of variance was used to analyze the data, and scanning electron microscopy was used to examine specimen fracture surfaces. The whisker-silica/CPC ratio had significant effects on composite properties (p < 0.001). When this ratio was increased from 0:1 to 1:0, the strength was increased by about three times, work-of-fracture by five times, and modulus by two times. Whisker surface treatments and CPC filler silanization also had significant effects (p < 0.001) on composite properties. Scanning electron microscopy revealed rough fracture surfaces for the whisker composites with steps and whisker pullout. Resin remnants were observed on the surfaces of the pulled-out whiskers, indicating strong whisker-matrix bonding. In conclusion, incorporating highly osteoconductive CPC fillers and ceramic whiskers yielded composites with substantially improved mechanical properties compared with composites filled with CPC particles without whiskers. The composite properties were determined by whisker-to-CPC ratio and filler surface treatments.

Elaboration and characterization of flat membrane supports from Moroccan clays. Application for the treatment of wastewater

The coatings ZrB2 and Zr-B-N were deposited by magnetron sputtering of ZrB2 target in Ar and Ar–15%N2 atmospheres. The structure and properties of the coatings were investigated via scanning and transmission electron microscopy, energy dispersion analysis, optical profilometry, glowing discharge optical emission spectroscopy and X-ray diffraction analysis. Mechanical and tribological properties of the coatings were investigated using nanoindentation, “pin-on-disc” tribological testing and “ball-on-plate” impact testing. Free corrosion potential and corrosion current density were measured by electrochemical testing in 1 N H2SO4 and 3.5%NaCl solutions. The oxidation resistance of the coatings was investigated in the 600–800 °C temperature interval. The coatings deposited in Ar contained 4–11 nm grains of the h-ZrB2 phase along with free boron. Nitrogen-containing coatings consisted of finer crystals (1–4 nm) of h-ZrB2, separated by interlayers of amorphous a-BN. Both types of coatings featured hardness of 22–23 GPa; however, the introduction of nitrogen decreased the coating’s elastic modulus from 342 to 266 GPa and increased the elastic recovery from 62 to 72%, which enhanced the wear resistance of the coatings. N-doped coatings demonstrated a relatively low friction coefficient of 0.4 and a specific wear rate of ~1.3 × 10−6 mm3N−1m−1. Electrochemical investigations revealed that the introduction of nitrogen into the coatings resulted in the decrease of corrosion current density in 3.5% NaCl and 1 N H2SO4 solution up to 3.5 and 5 times, correspondingly. The superior corrosion resistance of Zr-B-N coatings was related to the finer grains size and increased volume of the BN phase. The samples ZrB2 and Zr-B-N resisted oxidation at 600 °C. N-free coatings resisted oxidation (up to 800 °C) and the diffusion of metallic elements from the substrate better. In contrast, Zr-B-N coatings experienced total oxidation and formed loose oxide layers, which could be easily removed from the substrate.

The composites of biopolymer chitosan obtained from the swamp fish scale with bentonite as clay minerals has been characterized by the structural, mechanical, surface functional group and composition properties using scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), X-ray fluorescence (XRF) and X-ray Diffraction (XRD) analysis. The morphology structure obtained by SEM for the original chitosan, bentonite, and its composites showed that the particles are relatively well dispersed in the chitosan matrix. The physicochemical properties of the chitosan-bentonite composites depend significantly on the chemistry of the polymer matrices, the nature of bentonite, their modification, and the preparation methods that showed by SEM, TGA, XRF and XRD analysis. The obtained composite of chitosan bentonite was then applied for treating raw water sources of drinking water in Bilu river, South Kalimantan, during the dry season. The raw water sources contained a high value of turbidity (ca. of 370±30 NTU) and color (1300±150 Pt-Co). Batch experiment using the composite of chitosan bentonite for treating raw water sources was significant to reduce the value of turbidity, and the color becomes 24.8±2 NTU and 86.7±5 Pt-Co, respectively. The results then compare to the treatment using the commercial chitosan and bentonite self. Moreover, it found that the raw water treatment using the composite of chitosan-bentonite is more favorable than chitosan and bentonite materials.

Development of Iron Matrix Antifriction Composite Coatings

Patents

The surfactant addition effect in the elaboration of electrodepositated NiP-SiC composite coatings