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AbstractThe operating time of a diesel locomotive indicates its mechanical states to a certain scale. Though, even the same variant of diesel locomotive with the same types of operating hours shows different technical states in different types of operative environments. Therefore, it is quite intricate to obtain the data for entire life or general life prediction methods are required to study the physical failure mechanism. In pursuant of the discussed cases, mathematical model of diesel locomotive’s life estimation with respect to downward trend and neural networks is evolved in the study. Primarily, the parameters corresponds to downward trends are selected and the sample data is to be standardized & then the principal component analysis method is being used to simplify different parameters to a pervasive parameter. Method of interpolation is being used for the parameter’s time series data as the train data of neural network. Finally, the life span estimation model of the locomotive engine based on neural network is evolved.

We grow dense carbon nanotube forests at 450 °C on Cu support using Co/Al/Mo multilayer catalyst. As a partial barrier layer for the diffusion of Co into Mo, we apply very thin Al layer with the nominal thickness of 0.50 nm between Co and Mo. This Al layer plays an important role in the growth of dense CNT forests, partially preventing the Co–Mo interaction. The forests have an average height of ∼300 nm and a mass density of 1.2 g cm–3with tubes exhibiting extremely narrow inner spacing. An ohmic behavior is confirmed between the forest and Cu support with the lowest resistance of ∼8 kΩ. The forest shows a high thermal effusivity of 1840 J s–0.5m–2K–1, and a thermal conductivity of 4.0 J s–1m–1K–1, suggesting that these forests are useful for heat dissipation devices.

An experimental study was undertaken to understand the influence of load obliquity on ultimate pullout capacity of pile. Twenty, single free-head vertical piles in the form of micropiles of 20 mm diameter and 600 mm lengths were drilled using an auger and grouted under gravity in uniform sand bed. Ample cured micropiles were tested at 0°, 5°, 10°, 15°, 20°, 30°, 45°, 60°, 75° and 90° load inclinations with respect to axis of micropile i.e. vertical. Ultimate pullout capacity at each load inclination was determined from load-displacement curves using double tangent intersection method. It is found that ultimate oblique pullout capacity as well as vertical pullout capacity of micropile decreases as load inclination increases with axis of micropile. To understand the relationship between the two components of oblique pullout load an interaction diagram has been derived from test results which show that horizontal load significantly affects vertical pullout capacity than vice versa. Test results of similar studies on micropiles have been presented through a polar diagram. An attempt has also been made to assess the applicability of existing theories to estimate the ultimate pullout capacity of micropiles under oblique loads.

We use oxygen plasma to increase the height of forests from ∼0.2 to >2 mm. The effectiveness of treating alumina by oxygen plasma, prior to iron nanoparticle formation, is studied using cycles of nanotube growth, nanotube burning, and regrowth. This demonstrates that plasma-treated alumina is more resistant to iron bulk diffusion than an untreated one. Secondary ion mass spectroscopy shows there is negligible iron diffusion into the bulk of treated alumina. Plasma treatment of catalyst supports is potentially useful for growth of ultra-high-density nanotube forests for applications such as interconnects in integrated circuits and heat sinks.

The key atomistic mechanisms of graphene formation on Ni for technologically relevant hydrocarbon exposures below 600 °C are directly revealed viacomplementary in situscanning tunneling microscopy and X-ray photoelectron spectroscopy. For clean Ni(111) below 500 °C, two different surface carbide (Ni2C) conversion mechanisms are dominant which both yield epitaxial graphene, whereas above 500 °C, graphene predominantly grows directly on Ni(111) viareplacement mechanisms leading to embedded epitaxial and/or rotated graphene domains. Upon cooling, additional carbon structures form exclusively underneath rotated graphene domains. The dominant graphene growth mechanism also critically depends on the near-surface carbon concentration and hence is intimately linked to the full history of the catalyst and all possible sources of contamination. The detailed XPS fingerprinting of these processes allows a direct link to high pressure XPS measurements of a wide range of growth conditions, including polycrystalline Ni catalysts and recipes commonly used in industrial reactors for graphene and carbon nanotube CVD. This enables an unambiguous and consistent interpretation of prior literature and an assessment of how the quality/structure of as-grown carbon nanostructures relates to the growth modes.

In the present research a salt of vincamine, a poorly bioavailable indole alkaloid derived from the leaves of Vinca minor L., was synthesized in the solid state by means of a mechanochemical process employing citric acid as a reagent. The mechanochemical process was adopted as a solvent-free alternative to classical citrate synthetic route that involves the use of solvents. Since the mechanochemical salification is little studied to date and presents the disadvantage of offering a low yield, in this work, the influence of three process and formulation variables on the percentage of vincamine citrate was studied. In particular, the time of mechanical treatment (in planetary mill Fritsch P5) and the amount of citric acid were varied in order to evaluate their effect on the yield of the process, and the introduction of a solid solvent, a common pharmaceutical excipient (sodium carboxymethylcellulose, NaCMC), was considered. Due to the complexity of the resulting samples’ matrix, an appropriate experimental design was employed to project the experimental trials and the influence of the three variables on the experimental response was estimated with the help of a statistical analysis. The experimental response, that is, the yield of the process corresponding to the percentage of vincamine in the protonated form, was unconventionally calculated by means of X-ray photoelectron spectroscopy analysis (XPS). Out of 16 samples, the one with the highest yield was the coground sample containing vincamine and citric acid in a 1:2 molar ratio, treated for 60 min in the presence of NaCMC. Under the above conditions the salification reaction was completed highlighting the importance of a proper selection of process and formulation variables of the mechanochemical salification, and emphasizing the crucial role of the solid solvent in facilitating the salification. The second step of the research encompassed the characterization of the citrate salt obtained by solid excipient assisted mechanochemical salification (SEAMS) in comparison with the vincamine citrate obtained by classical synthetic route. The samples were characterized by, besides XPS, high resolution transmission electron microscopy (HRTEM), X-ray powder diffraction (XRPD), in vitrosolubilization kinetics and in vivooral pilot study in rats. Finally, in order to monitor over time possible disproportionation phenomena, stability studies have been performed by repeating XPS analysis after 8 months. As expected, the the SEAMS-vincamine salt consisted of particles both crystalline and amorphous. The solubilization kinetics was superior to the corresponding salt probably thanks to the favorable presence of the hydrophilic excipient although the two salts were bioequivalent in rats after oral administration. Furthermore, no evidence of disporportionation phenomena in the SEAMS-vincamine salt was found after storage. In conclusion, in the case of forming salts of poorly soluble drugs, the SEAMS process may be an interesting alternative to both classical synthetic routes, eliminating the need for solvent removal, and simple neat mechanochemical salification, overcoming the problem of limited process yield.

Glasses having compositions 20B2O3.(79.5-x)Bi2O3.xSiO2 (10 ≤ x ≤ 40) doped with 0.5 mol% of Sm 3+ ions were prepared by melt quench technique. The amorphous nature of the glasses was confirmed by X-ray diffraction studies. The spectroscopic properties of Sm 3+ ions in bismuth borosilicate glasses as a function of bismuth oxide were investigated using optical absorption and fluorescence spectra. The Judd-Ofelt theory has been employed to calculate transitions probability from the data of absorption cross-section of several f-f transitions. The intensity parameters Ω2 is related to the symmetry of glass hosts, where as the parameter Ω6 is inversely proportional to the rare earth oxygen (RE-O) covalency. The variation of Ω4 with Bi2O3 content has been attributed to rigidity of the samples. Using the Judd Ofelt intensity parameters the other radiative properties like radiative transition probability, radiative life time, branching ratio and the stimulated emission cross-sections of prepared BBSS glasses have been calculated. A bright fluorescent orange emission at 600 nm (4 G 5/2 → 6 H 7/2) of Sm 3+ ion has been investigated as a function of Bi2O3 in host glass. The radiative transition probabilities of Sm 3+ ions are large in bismuth borosilicate glasses, suggesting the suitability of these glasses as potential candidate for laser application.

AbstractBased on a survey of boards of non-profit organizations in India, this paper examines the extent to board effectiveness is influenced by board inputs, structures and processes. The findings provide mixed support for the normative literature on board effectiveness. Using stepwise logistic regression the research suggests that board inputs and three process variables are important in explaining board effectiveness, namely: board members have the time, skills and experience to do the job; clear board roles and responsibilities; the board and management share a common vision of how to achieve their goals; and the board and management periodically review how they work together.