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SUMMARYA solution procedure for the analysis of planar and axisymmetric contact problems involving sticking, frictional sliding and separation under large deformations is presented. The contact conditions are imposed using the total potential of the contact forces with the geometric compatibility conditions, which leads to contact system matrices and force vectors. Some key aspects of the procedure arc the contact matrices, the use of distributed tractions on the contact segments for deciding whether a node is sticking, sliding or releasing and the evaluation of the nodal point contact forces. The solutions to various sample problems are presented to demonstrate the applicability of the algorithm.

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The application of computer-aided design and manufacturing techniques is becoming essential in modern metal-forming technology. Thus process modeling for the determination of deformation mechanics has been a major concern in research . In light of these developments, the finite element method--a technique by which an object is decomposed into pieces and treated as isolated, interacting sections--has steadily assumed increased importance. This volume addresses advances in modern metal-forming technology, computer-aided design and engineering, and the finite element method.

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The leaves of Ocimum sanctum were extracted in methanol (OsM) and sequentially fractionated with n-hexane (OsH), ethylacetate (OsE) and butanol (OsB) to find the best extraction solvent for antioxidants from the herb known for its medicinal values. OsB was rich in both total polyphenolic content (TPC) (212.26 ± 6.3 mg GAE/ g extract) and total flavonoid contents (TFC) (54.51 ± 3.5 mg QE/g extract). OsE also had significantly high TPC (202.71 ± 5.5 mg GAE/g extract). The EC 50 based on DPPH (3.91 ± 0.3 lg/ml), ABTS (1.6 ± 0.1 lg/ ml) and phosphomolybdate (2.31 ± 0.1 lg/ml) for OsB; hydroxyl (5.3 ± 0.4 lg/ml), superoxide (7.32 ± 0.9 lg/ ml) radicals for OsM and DPPH (8.61 ± 0.6 lg/ml), phosphomolybdate (2.43 ± 0.1 lg/ml) and ABTS (5.3 ± 0.4 lg/ml) for OsE were lower than ascorbic acid showing potential antioxidant properties. EC 50 values of different fractions for DPPH anion, ABTS cation free radical scavenging and phosphomolybdate reducing property were significantly and positively correlated with TPC and TFC. LC-MS analysis of OsB and OsE showed the presence of luteolin, apigenin, rosmarinic, chlorogenic, caffeic acid and their derivatives. Quercetin is extracted in ethylacetate fraction. Overall data revealed that O. sanctum leaf extracts in butanol and ethylacetate with high polyphenolics and flavonoids, had strong antioxidant potential.

Plants and plant-derived materials play an extremely important role in pest management programs. Essential oil from wood chips of Himalayan Cedar, Cedrus deodara (Roxburgh) Don (Pinales: Pinaceae), was obtained by hydrodistillation and fractionated to pentane and acetonitrile from which himachalenes and atlantones enriched fractions were isolated. A total of forty compounds were identified from these fractions using GC and GC-MS analyses. Essential oils and fractions were evaluated for insecticidal activities against second instars of the diamondback moth, Plutella xylostella L. (Lepidoptera: Yponomeutidae), using a leaf dip method. All samples showed promising larvicidal activity against larvae of P. xylostella. The pentane fraction was the most toxic with a LC50 value of 287 µg/ml. The himachalenes enriched fraction was more toxic (LC50 = 362 µg/ml) than the atlantones enriched fraction (LC50 = 365 µg/ml). LC50 of crude oil was 425 µg/ml and acetonitrile fraction was LC50 = 815 µg/ml. The major constituents, himachalenes and atlantones, likely accounted for the insecticidal action. Present bioassay results revealed the potential for essential oil and different constituents of C. deodara as botanical larvicides for their use in pest management.