The interacting mechanisms of corrosion and fatigue wear of the CrN coated piston rings were investigated in two ways: (1) by comparing the laboratory test data to field results, and (2) by ...simulating the stress distribution and crack origins in the CrN coating using a Finite Element Method (FEM). The surface and interface characterizations confirmed that fatigue wear resulted in cracking and spalling of the CrN coating. At the same time, corrosive wear was promoted by sulfur incursion along boundary defects in the CrN coating. FEM simulations showed that the magnitude of stresses at the interface of Cr particle/CrN matrix was a function of Cr particulate sizes, and they also identified crack initiation sites at rubbing contacts. The dominant factors contributing to the propagation of the surface/subsurface cracking were elucidated. Inherent defects initiated cracks, and the repetitive shear stress coupled with the effects of corrosive species gave rise to an acceleration of crack enlargement and subsequent severe spalling of the CrN coating.
•The corrosion and wear-related failure mechanisms of a CrN piston ring were evaluated.•The origin of microcracks of coated piston rings was modelled by finite element methods.•TEM observations traced sulfur and alkaline constituents to indicate corrosion.•The interplay of corrosion and fatigue cracking to cause CrN coating failure was discussed.
•Saffron composition is investigated by inductively coupled plasma mass spectrometry.•Potentiality of mineral composition for traceability purposes is evaluated.•Classification of spices coming from ...three Italian regions is attempted.
27 Saffron spices produced in three Italian regions, Abruzzo (L’Aquila), Umbria and Sardinia, were analysed by inductively coupled plasma-mass spectrometry to test potentiality of mineral composition for geographical traceability. A linear discriminant analysis (LDA) based on concentrations of 12 selected elements, Li, B, Na, Ga, Rb, Sr, Zr, Nb, Cs, Ba, Sm, and Hf, allows more than 80% of correct predictions in leave-one cross-validation. Four elements (B, Na, Sr and Rb), identified by step-wise LDA, provide more than 90% of correct predictions. Moreover, saffron spices cultivated in Sardinia and Central Italy can be distinguished under more severe validation conditions (20% of samples in the prediction set). In summary, mineral composition results a promising indicator of saffron geographical origin.
A number of industrial and technical lignins from forestry and agriculture were extracted by different chemical pulping processes and characterized by evaluating their physical and chemical ...properties. Several qualitative and quantitative methods were performed to elucidate lignin profiles and their potentials as substitutes for use in biobased products. The morphology, molecular weight distributions, elemental compositions, glass transition temperature, and several important functional groups containing hydroxyl units such as phenolic, aliphatic, and carboxylic acid were classified and their contents were determined quantitatively by employing 31P NMR spectroscopy. The emerging information is relevant to pressing scientific development issues for value-added applications from lignins during industrial production of biomaterials.
Various types of neuromuscular diseases differ in symptoms, pathology, and clinical picture but one of their common elements is muscle weakness, which could lead to human motor activities impairment ...and in many cases to shortening of life span and even death due to respiratory failure. That is why it is very important to better understand the underlying causes of these diseases to be able to implement new methods of treatment more effectively. This paper presents the results of the elemental analysis of human muscular tissues affected by dystrophy and myopathy. For this purpose, the particle-induced X-ray emission method was used, which is perfectly suited for measuring light elements. The samples were analysed for differences in the elemental composition of Na, Mg, P, S, Cl, K, Fe, Zn, and Br. The results were presented in the form of elemental concentration maps and a thorough statistical analysis of the obtained data using the advanced statistical methods.
Abstract
Faecal sludge (FS) is not extensively evaluated for its potential as a solid fuel mainly due to the general conception of its “highly variable characteristics” in relation to the wide range ...of on-site sanitation systems. An extensive and systematic FS characterization was therefore conducted on twenty-four samples collected directly from pit latrines, ventilated improved pit latrines (VIPs) and urine-diverting dehydrating toilets (UDDTs) at two depths to understand the impact on properties relevant for combustion. The higher heating value (HHV) for these samples lies between 13 to 22 MJ/kg DM (dry matter). However, such high values should be taken with caution since the measurement guidelines recommended the removal of the large inert pieces found in FS. Besides this potential bias of procedure, differences could be observed between containments, where pit latrines showed the largest variability as compared to VIP and UDDT. These differences are mainly correlated with the ash content, ranging from 15 to 50% DM, while the organic elements concentrations were similar for all samples. Interestingly, the same major inorganic elements could be measured in all samples, namely Si, P, Ca and K followed by Mg and Na. Such similar composition is probably due to similar sanitation practices and staple diet. However, the overall concentration of minor elements was below 1000 ppm DM for most samples. The N concentrations were quite high, between 2.5 to 4.5% DM. Abovementioned results may be problematic for process and environmental aspects if FS is combusted alone. FS can therefore be suitable preferably for co-combustion in blend with lignocellulosic biomass waste.
The goal of this research is to synthesize bismuth molybdate (γ-Bi
2
MoO
6
) nanoparticles via hydrothermal approach which involved the use of bismuth nitrate and ammonium molybdate as a precursor. ...The resultant product was undergoing spectroscopic characterization techniques to understand the properties of γ-Bi
2
MoO
6
NPs. Additionally, the absorbance and band gap of the bismuth molybdate nanoparticles were measured using a UV–visible spectrophotometer. According to the results obtained by the band gap, the calculation is around 2.4 eV. The photocatalytic efficacy was investigated using methylene blue (MB) dye by utilizing a visible light source for 2 h. The formation of hydroxyl radicals is the responsible species for degradation confirmed by the scavenger analysis. The reusability and photostability were determined by recycling studies. According to the degradation efficiency calculation, about 93.4% MB dye was effectively degraded by the synthesized bismuth molybdate. Furthermore, the electrochemical impedance analysis revealed the capacitance of the bismuth-modified electrode.
(NH4)2SO4 solution was employed to pre-treat regenerated cellulose fiber (from bamboo) using an ultrasonic method, and then the material was heat-treated at 250 °C. Scanning electron microscopy ...revealed that erosion and cracks of the fiber surface increased after being impregnated with (NH4)2SO4 combined with ultrasonic pretreatment. There was a small change in the intensity and the position of some peaks in the Fourier transform infrared spectra, and in the heat treatment, partial pyrolysis of the cellulose occurred. The data showed that for the cellulose fiber pretreated with 5 wt% (NH4)2SO4 the decomposition temperature shifted to the lower side (252 °C), and the decomposition range (180 °C to 454 °C) was wider than for the other impregnation fibers and reference. However, the rate of decomposition was different with different concentrations of (NH4)2SO4. The C content of heat-treated fiber with 5 wt% (NH4)2SO4 increased to 52%. The above results indicated that the (NH4)2SO4 was an effective catalyst to pretreat regenerated cellulose fiber in the pathway of pyrolysis.
•Ge/Gd/Si alloys.•Solar Cells.•Double pulse laser induced plasma was produced and the emission spectra were analysed.•Alloy constituents were quantitatively determined by CF-LIBS technique.•Double ...pulse LIBS provide enhanced emission spectra and was used for the compositional analysis of Ge/Si alloys.
We applied variant of calibration free laser induced Breakdown Spectroscopy (CF-LIBS) approach for the compositional analysis of standard Gd/Ge/Si alloy and solar cells. The double pulse laser induced plasma was produced on the sample surface and the emission spectra were recorded at optimized interpulse delay and energy ratio. The Plasma temperature, determined using Boltzmann plot, was used to determine the concentration of all species present in a sample. The results are compared with reference values as well as conventional CF-LIBS results, which show that conventional and variant CF-LIBS results are similar and in close agreement to reference values. It is worth mention that the variant CF-LIBS results, but the approach is simpler and faster. Therefore, this approach was applied to three unknown polycrystalline silicon solar cells, which yield Al, C, Ca, Fe, In, Ti, Sb and Sn in the parts per million (ppm). This approach can potentially be applied for real-time trace monitoring in manufacturing processes of photovoltaic devices where conversion efficiency depends strongly on impurities’ concentration.
An archaeological excavation in Prostějov (Czech Republic) revealed a workshop of a local potter with colourless, pink, and blue powders presumably used to produce faience/surface decoration. A ...comprehensive analytical study, which combined elemental and molecular analysis techniques, was performed to shed light on the chemical composition of these unique findings. Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM EDX), inductively coupled-plasma mass spectrometry (ICP MS), flow injection analysis (FIA) with electrospray ionisation mass spectrometry (ESI MS), laser desorption ionisation mass spectrometry (LDI MS), and Raman spectroscopy were applied to reveal the elemental composition of the powders and identify the colouring agents in the pink and blue powders. The colouring agents in the pink powder were probably iron and the agent in the blue powder is Prussian blue. On top of that, it was also possible to determine the organic additives in these powders through pyrolysis gas chromatography with mass spectrometric detection (Py GC/MS), atmospheric solids analysis probe ion mobility mass spectrometry (ASAP IM MS), and LDI MS. The organic constituents were identified as plant resin, beeswax, and fats. These results point to the preparation of faience/pigment mixtures as oil paint.
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