Characterisation of Seed Lipids from Bixa orellana and Trachyspermum copticum

Bixa orellana L. seeds possess a resinous lipid (6.3 %), which has a pungent and spicy odour. The seed is known for its medicinal properties such as anti‐inflammatory, antipyretic activity and as a cure for tonsilitis. Trachyspermum copticum L. seed is a well known digestive aid and relief from colic pain. T. copticum possesses essential oil rich in thymol (>50 %) and lipid (15.6 %). The present study was aimed to quantify lipid classes of these two species by silicic acid chromatography and analyze their fatty acid composition by gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS). It was observed that the seed lipids are rich in neutral lipids with 98.1 and 95.2 % and lower quantities of glycolipids of 1.5 and 3.8 % and phospholipids of 0.36 and 1.0 % in B. orellana and T. copticum, respectively. The fatty acid composition of B. orellana seed lipid showed major quantities of palmitic (26.9 %), linoleic (26.1 %), oleic (17.5 %), linolenic (15.1 %), stearic acid (10.8 %) and small quantities of eicosanoic acid (3.6 %). In T. copticum seed lipids, petroselinic acid (68.3 %) and linoleic acid (25.3 %) together constituted 93 % of the total lipid. The results revealed that the lipids after recovery of the essential components namely, bixin and volatile oil from B. orellana and T. copticum, respectively can be further explored for industrial applications.     

Ultrathin PFPE Film Systems Fabricated by Covalent Assembly: An Application to Tribology

In this study, we have employed covalent molecular assembly to fabricate robust thin film structures comprising molecular layers and have demonstrated its application in tribology. An anhydride-functionalized polymer (gantrez) was deposited over an amine-functionalized silicon surface through covalent binding and employed as an intermediate layer between derivatized silicon and perfluoropolyether (PFPE). X-ray photoelectron spectroscopy, atomic force microscopy, and ellipsometry were employed to study the interfacial chemistry, morphology, and thickness of the assembled films. The films show excellent stability and strength against sonication, which can be attributed to the covalent interlayer linkage. Such films showed wear life of >100,000 cycles in ball-on-disk sliding tests at a normal load of 0.5 N and a sliding rotation of 200 rpm at a track radius of 3.2 mm. The performance was superior compared to that of PFPE-coated self assembled monolayers used as the lubricating layer. The film systems and assembly technique can be employed as nano-lubrication in several technological applications, such as information storage devices and micro-electro-mechanical systems.     

Artificial Neural Network modeling of a hydrogen dual fueled diesel engine characteristics: An experiment approach

The rapid growth of vehicular pollution; mostly running on the diesel engine, emissions emerging are the concerns of the day. Owing to clean burn characteristics features, Hydrogen (H₂) as a fuel is the paradigm of the researcher. Extensive research presented in the literature on H₂ dual fueled diesel engine reveals, the significant role of H₂ in reducing emissions and enhancing the performance of a dual fueled diesel engine. With meager qualitative experiment data, the feasibility to develop an efficient Artificial Neural Network (ANN) model is investigated, the developed model can be utilized as a tool to investigate the H₂ dual fueled diesel engine further. In the process of developing an ANN model, engine load and H₂ flow rate are varied to register performance and emission characteristics. The creditability of the experiment is ascertained with uncertainty analysis of measurable and computed parameters. Leave-out-one method is adopted with 16 data sets; seven training algorithms are explored with eight transfer function combinations to evolve a competent ANN model. The efficacy of the developed model is adjudged with standard benchmark statistic indices. ANN model trained with Broyden, Fletcher, Goldfarb, & Shanno (BFGS) quasi-Newton backpropagation (trainbfg) stand out the best among other algorithms with regression coefficient ranging between 0.9869 and 0.9996.     

Studies on the development of aluminium alloy–mild steel reinforced composite

With a view to developing a new metal–metal cast composite material as a possible substitute for ferrous materials in wear resistant applications, Al alloy (LM11) is reinforced with mild steel (ms) wires and it is heat treated to get ‘reaction interface’ (RI). Microhardness, tensile properties and wear characteristics of the matrix, as-cast and heat treated composites have been determined. While microhardness of the composite showed variation from 150 to 45 VHN across the interface in the as-cast composite, annealed (500–525°C) composite showed a microhardness of 350–420 VHN at the interface indicating the effectiveness of the heat treatment. It is seen that the % improvement in wear resistance increased with increase in number of wires when embedded in the aluminium alloy matrix. Further imrpovement of about 30% was observed when heat treated at 500°C for 15 h. These results have been discussed in terms of wetting between ms wires and the matrix, particularly the increase of hardness and tensile strength to the formation of ‘reaction interface’ due to annealing. The width of the interface increased with annealing time and temperature and the kinetics of reaction followed logarithmic and parabolic growth rate. The activation energy for the formation of intermetallics constituting the reaction interface is found to be 20.7 KJ mol⁻¹. From the measured hardness and ultimate tensile strength of the constituents and composites an empirical relation was deduced.     

Preparation, characterization and electrical conductivity studies of nanocrystalline La doped BaMoO4

Different compositions of scheelite type nanocrystalline La doped BaMoO₄ [Ba_1−xLa_xMoO_4+x/2, where x = 0, 0.1, 0.2, 0.3, 0.4 and 0.5] samples were prepared by acrylamide assisted sol-gel combustion process. Dried gels prepared at 60 °C were heated at different temperatures and characterized using TG/DTA, XRD, FTIR and SEM-EDX techniques. From XRD patterns, crystalline phases for La doped BaMoO₄ samples were confirmed and their average crystallite sizes were calculated using Scherrer's formula and it was found to be less than 80 nm. Structure and thermal behavior of scheelite type nanocrystalline La doped BaMoO₄ samples were identified respectively using FTIR and TG/DTA measurements. Microstructure and existence of O, La, Ba and Mo elements in the La doped BaMoO₄ samples were obtained from SEM-EDX and HRTEMtechniques. The ‘d’ spacing values were obtained for different (h k l) planes and were well matched with the standard BaMoO₄. (h k l) values for different directions of planes were assigned for the observed HRTEM images and were matched with standard BaMoO₄. Grain and grain boundary conductivities were evaluated by analyzing the impedance data, using the Winfit software, measured at different temperatures.     

Efficient Algorithms for Reliability Analysis of Planar Networks?A Survey

We survey some recent polynomial-time algorithms for the exact computation of network reliability. The algorithms apply to several classes of planar networks, which include series-parallel, inner-cycle-free, inner-four-cycle-free and planar cube-free. We describe these classes and discuss the related polynomial algorithms for computing their reliability.