Tool Wear and its Effect on Residual Tensile Strength in Drilling of Quartz Cyanate Ester Polymeric Composite

Quartz-Fibre-Reinforced cyanate ester Plastics (QFRP) has superior performance in terms of mechanical, electromagnetic properties and are being widely used in military applications. Drilling is the general machining process for making hole to join the composite part to another sub-assembly. This study presents an influence of optimized drilling parameters on carbide tool wear and its impact on hole characteristics in QFRP composite. The aim is to achieve the optimum use of drill during the drilling process from application perspective without compromising the quality. In addition, the effect of tool wear and its impact on residual tensile strength of quartz composite are studied. The dominant wear mechanism observed is flank wear caused by the abrasive nature of the quartz fibre. The tool wear and delamination factor after drilling 200 holes are 186 µm and 1.40 respectively. The residual strength is affected by the tool wear due to relatively poor interlaminar property between fiber and resin in this quartz composite. The residual strength of quartz specimen drilled with the tool after drilling 200 holes is 14 % lower than the property of specimen drilled with fresh drill. The highlight of the present work is a combined analysis of wear in the tool, delamination induced and residual strength of quartz specimen. The results of this study strengthen the understanding of the drilling process of quartz polymeric composite material in aerospace applications

Higher terpenes from lower terpenes: a short, simple and versatile route to bisabolane sesquiterpenoids

An efficient procedure for the elaboration of abundantly available monoterpenes to bisabolane sesquiterpenes utilising catalysed ene addition as the key reaction is described

Olefin metathesis in polycyclic frames. A total synthesis of hirsutene

A synthesis of the tricyclic sesquiterpene hydrocarbon (±)-hirsutene, involving a novel photo-thermal metathetic sequence as the key step to generate the linearly fused tricyclopentanoid framework, is reported

Lewis acid catalysed [2+2] cycloreversion of cookson's cage ketones under ambient conditions: model system for light energy conversion

Design of 'push-pull' Cookson's cage ketones and their quantitative [2+2] cycloreversion to cis, syn,cis -triquinanes at room temp, under Lewis acid catalysis, is reported. This observation has promising ramifications on the utility of 1 2 system for reversible storage of solar energy

Synthesis and rearrangements of the pentacyclo[5.4.0.0.0.0]undecane [1,2,4-trishomocubane] ring system

Two syntheses of the pentacyclo[5.4.0.02,6.03,10.04,8]undecane (1,2,4-trishomocubane) system are described. The first synthesis involves intramolecular photochemical [2 + 2]-cycloaddition of the triquinane bisenones (14a-d) to furnish the 1,2,4-trishomocubanediones (15a-d). The second approach is based on a boron trifluoride-diethyl ether-catalysed rearrangement of the readily available Cookson's caged diketones (16a,b) to 1,2,4-trishomocubanediones (17a,b). Thermal and acid-catalysed [2 + 2]-cycloreversions of (15a,c,d) and (17a,b) to linear fused triquinanes (14a,c,d), (20a,b) and tricyclo[5.3.1.02,6]undecane systems of current synthetic interest are also described

Olefin metathesis in polycyclic frames 1. A new way to cis, syn, cis- tricyclopentanoids (acs-C<SUB>11</SUB>-triquinanes)

A novel olefin metathesis sequence permits ready access to functionalised cis, syn, cis -tricyclo [6.3.0.02,6] undecane based bis-enones. These bis-enones have been shown to undergo cage cyclisation in sunlight with remarkable ease and efficiency

A total synthesis of (±)-coriolin

A simple synthesis of (&#177;)-coriolin (4) from the readily available cis, anti, cis-tricyclic C13-dione (5) is reported

A general approach to linearly fused triquinane natural products. Total syntheses of (.+-.)-hirsutene, (.+-.)-coriolin, and (.+-.)-capnellene

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Percutaneous pinning of supracondylar fracture humerus with crossed kirschner wires after closed reduction under image intensifier guidance in paediatric age group

Background: The common pediatric injuries around elbow are supracondylar fractures of humerus. Some of them are displaced - Gartland2 and 3. These fracturesmay causecomplications like deformities and neurovascular problems without reduction and fixation. Percutaneous pinning with crossed k-wires show good results among different method used for treatment. Method:40 patients between the age groups 2 -10 years were treated with percutaneous pinning with crossed kirschner wires, after closed reduction under guidance of image intensifier(C-ARM). These patient come under Gartland 2&amp;3 according to classification and treated between 2012-2015. The fractures are around seven days old. Flynn’s criteria used for assessing clinical results. Results: The age groups 2 -10 years were treated with mean age- 5 years. The follow-up duration 2-4 years-mean2 years. The outcomes were assed with Flynn`s criteria and found to be excellent in 28, good in 10, fair in 1,poor in 1. Conclusion: Percutaneous pinning with crossed k-wires show good results among different method used for treatment for Gartland 2&amp;3 supracondylar fractures in paediatric age