Wild Brazilian Mustard (Brassica juncea L.) Seed Oil Methyl Esters as Biodiesel Fuel

Wild mustard (Brassica juncea L.) oil is evaluated as a feedstock for biodiesel production. Biodiesel was obtained in 94 wt.% yield by a standard transesterification procedure with methanol and sodium methoxide catalyst. Wild mustard oil had a high content of erucic (13(Z)-docosenoic; 45.7 wt.%) acid, with linoleic (9(Z),12(Z)-octadecadienoic; 14.2 wt.%) and linolenic (9(Z),12(Z),15(Z)-octadecatrienoic; 13.0 wt.%) acids comprising most of the remaining fatty acid profile. The cetane number, kinematic viscosity, and oxidative stability (Rancimat method) of the methyl esters was 61.1, 5.33 mm² s⁻¹ (40 °C) and 4.8 h (110 °C), respectively. The cloud, pour and cold filter plugging points were 4, −21 and −3 °C, respectively. Other properties such as acid value, lubricity, free and total glycerol content, iodine value, Gardner color, specific gravity, as well as sulfur and phosphorous contents were also determined and are discussed in light of biodiesel standards ASTM D6751 and EN 14214. Also reported are the properties and composition of wild mustard oil, along with identification of wild mustard collected in Brazil as Brassica juncea L. (2n = 36) as opposed to the currently accepted Sinapis arvensis L. (2n = 18) classification. In summary, wild mustard oil appears to be an acceptable feedstock for biodiesel production. Disclaimer: Product names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable.     

Electrical resistivity as a measure of change of state in substrates: Design, development and validation of an automated system

Intrinsically smart structural composites are materials, which can perform function such as sensing strain, stress damage or temperature. Electrical resistance could potentially serve as an indicator of structural well-being or damage in the structure. To this end, the development of an automated resistance measurement system is desired. An automated nodal electrical resistance acquisition circuitry (NERAC) was designed, and interfaced to a laptop for measurement of electrical resistance/impedance from the substrate of interest. Measurements were carried out using DC/AC method with four-point probe technique. Baseline reading before damage was noted and compared with the resistance measured after damage. The device was calibrated and validated on three different substrates: PVDF samples, composite panels and smart concrete. Results conformed to previous work done on these substrates, validating the effective working of the NERAC device. Change of state of the substrate, after damage was assessed by measurement of resistance/impedance.     

Plasma effects in semiconducting nanowire growth

Three case studies are presented to show low-temperature plasma-specific effects in the solution of (i) effective control of nucleation and growth; (ii) environmental friendliness; and (iii) energy efficiency critical issues in semiconducting nanowire growth. The first case (related to (i) and (iii)) shows that in catalytic growth of Si nanowires, plasma-specific effects lead to a substantial increase in growth rates, decrease of the minimum nanowire thickness, and much faster nanowire nucleation at the same growth temperatures. For nucleation and growth of nanowires of the same thickness, much lower temperatures are required. In the second example (related to (ii)), we produce Si nanowire networks with controllable nanowire thickness, length, and area density without any catalyst or external supply of Si building material. This case is an environmentally-friendly alternative to the commonly used Si microfabrication based on a highly-toxic silane precursor gas. The third example is related to (iii) and demonstrates that ZnO nanowires can be synthesized in plasma-enhanced CVD at significantly lower process temperatures than in similar neutral gas-based processes and without compromising structural quality and performance of the nanowires. Our results are relevant to the development of next-generation nanoelectronic, optoelectronic, energy conversion and sensing devices based on semiconducting nanowires.     

Comparison of photostability, optical and structural properties of TiO2/conjugated polymer hybrid composites prepared via different methods

In this work, we have synthesized high quality TiO₂ nanocrystallites by sol-gel method (TiO₂ white (w)) and compared its properties with the ones synthesized by the simple hydrolysis method in aqueous solution (TiO₂ transparent (t)). The TiO₂/MEH-PPV nanocomposites are formed mainly by two ways: (i) Prepared in the form of the colloidal solution by adding the known concentration of the TiO₂ in MEH-PPV and then sonicate it well; (ii) In the thin film form by depositing the above solution over a glass substrate by spin coating. The properties of the resulting dispersions could be tailored by varying the composition and concentration of TiO₂ nanoparticles in CP's. The TiO₂ nanoparticles prepared by both methods show anatase character of TiO₂ as elucidated by X-ray diffraction (XRD) studies. Transmission electron microscopic (TEM) studies reveal that the transparent colloidal suspension of TiO₂ exhibits agglomeration of TiO₂ nanoparticles (size ~ 150-300 nm) and this trend is maintained in the MEH-PPV matrix for TiO₂/MEH-PPV composites as well. However, the composite obtained by mixing MEH-PPV with sol-gel prepared TiO₂(w) shows uniform nanoscale dispersion of TiO₂ (size ~ 20 nm) in MEH-PPV matrix. The UV-VIS absorption, photoluminescence (PL) and lifetime studies confirm the presence of dynamic quenching effect indicating efficient photoinduced charge transfer in TiO₂/MEH-PPV hybrid composites particularly with white TiO₂. It is conjectured that the devices containing TiO₂/MEH-PPV composites for TiO₂ prepared by the sol-gel method should lead to significant improvement in the photovoltaic performance of TiO₂/MEH-PPV hybrid solar cells.     

Prediction of gel-time in the cure of unsaturated polyester resins: Phenomenological modeling vs. statistical analysis

A series of kinetic and rheological measurements were carried out using a differential scanning calorimeter (DSC) and a Rheometrics Dynamic Analyzer (RDA). The effects of temperature, inhibitor level, initiator level, and initiator type on the curing of unsaturated polyester resins were investigated. Two models based on the free radical polymerization mechanism were developed for predicting the time to reach liquid-solid transition. These models adapted a concept that gelation occurred at a critical radical concentration. The applicability of these models was compared to that of a statistical analysis.     

Crowd abnormality detection in video sequences using supervised convolutional neural network

Multimedia Tools and Applications - In this paper, a Convolutional Neural Network (CNN) based crowd abnormality detection model in video sequences is proposed. The model has two convolution layers,...     

Stochastic fracture analysis of laminated composite plate with arbitrary cracks using X-FEM

In this paper, second order statistics of mixed mode stress intensity factors (MSIFs) and crack propagation analysis of the symmetric angle ply laminated composite plate with through thickness arbitrary curve cracks subjected to tensile and shear stress is presented. The fracture behaviour is analysed using extended finite element method (X-FEM). The cracks like line, semi elliptical, semi circular and arbitrary curves are considered for the detailed numerical study. The material properties, lamination angle, loading, crack width and crack depth are modelled as independent, combine uncorrelated and correlated input random Gaussian variables. The interaction integral (M-integral) is adopted for calculating the MSIFs. The second order perturbation technique and Monte Carlo simulations are proposed to obtain the mean and coefficient of variance of MSIFs by random change in input system parameters. This work signifies the accurate and realistic evaluation of fracture response by handling the various levels of uncertainties. The effect of crack propagation on MSIFs using tensile and shear stresses using global tracking algorithm is also highlighted.     

Open contact analysis of single bit failure in 0.18 μm technology

Single bit failure is the most common failure mode in static random access memory. Although a failing cell can be easily localized with bitmap data, the exact defect location within the failing cell cannot be found immediately, especially when a defect is related to contact. In this paper, a technique of contact-level passive voltage contrast has been proposed to detect such defects for a single bit failure. After an open contact was identified, subsequent transmission electron microscope analysis was performed and it was found that the root cause for the open contact was poly residue.     

Capacity investment and the value of operational flexibility in manufacturing systems with product blending

A distinct feature of process industries such as food, chemical and consumer packaged goods is the blending of intermediates into finished goods. In the context of such manufacturing systems the levels of different inputs that can be blended to process a final good define the range of flexibility. Likewise, the cost for using (blending) different inputs defines the mobility element of flexibility. In this paper, we investigate capacity investment and the value of flexibility in the presence of such product blending constraints. We are motivated by recent case studies of food manufacturers, in particular, those manufacturers that seek to increase flexibility via blending of intermediates. We analyse stochastic programs under demand uncertainty of such manufacturing systems. We provide analytical insights into trade-offs when range and mobility are interdependent. Our analytical work gives structural insights into subtle complementarity and substitution effects between dedicated and shared resources in the presence of blending. We analytically show that there is a degradation in the cost performance of such systems with an increase in correlation. We characterise the optimal blending fraction that balances the benefits of higher range with higher costs (lower mobility). Our numerical work shows that a moderate level of blending can significantly improve flexibility and that well-known guidelines for designing limited flexibility change in the presence of blending. For example, blending, even if optimally designed, weakens the appeal of chaining configurations. Overall our work guides resource configuration in industries where product blending is an integral part of the production process.