An overview of burst, buckling, durability and corrosion analysis of lightweight FRP composite pipes and their applicability

© 2019 Elsevier Ltd. All rights reserved.The main aim of this review article was to address the performance of filament wound fibre reinforced polymer (FRP) composite pipes and their critical properties, such as burst, buckling, durability and corrosion. The importance of process parameters concerning merits and demerits of the manufacturing methods was discussed for the better-quality performance. Burst analysis revealed that the winding angle of ±55° was observed to be optimum with minimum failure mechanisms, such as matrix cracking, whitening, leakage and fracture. The reduction of buckling effect was reported in case of lower hoop stress value in the hoop to axial stress ratio against axial, compression and torsion. A significant improvement in energy absorption was observed in the hybrid composite pipes with the effect of thermal treatment. However, the varying winding angle in FRP pipe fabrication was reported as an influencing factor affecting all the aforementioned properties. Almost 90% of the reviewed studies was done using E-glass/epoxy materials for the composite pipe production. By overcoming associated limitations, such as replacing synthetic materials, designing new material combinations and cost-benefit analysis, the production cost of the lightweight FRP composite pipes can be decreased for the real-time applications.Peer reviewe

Interscalene brachial plexus block with bupivacaine and ropivacaine in patients with chronic renal failure: Diaphragmatic excursion and pulmonary function changes

In this randomized, double-blind study, we compared the anesthetic characteristics and pulmonary function changes of 0.33% bupivacaine and 0.33% ropivacaine used for interscalene brachial plexus (IBP) anesthesia in patients with chronic renal failure. Forty-two patients undergoing IBP anesthesia for creation of arteriovenous fistulas were randomly allocated to receive either 30 mL of 0.33% bupivacaine (Group B) or 0.33% ropivacaine (Group R). Block onset time, diaphragmatic excursion (ultrasonographic evaluation), and free plasma concentrations of bupivacaine and ropivacaine were evaluated. Negative motion or immobility of the ipsilateral hemidiaphragm and a decrease of > 10 mm in positive motion were defined as diaphragmatic paresis. The pulmonary function variables were measured by bedside spirometry equipment. Seven patients needed supplemental local anesthetic, one with total spinal block; these patients were excluded from the study. The success rate was 80.9%. Block quality was similar in the two groups. Ipsilateral hemidiaphragmatic excursion was decreased in both groups compared with baseline values (P 0.05). Pulmonary function significantly decreased from baseline in both groups (forced vital capacity (FVC) 30%, forced expiratory volume at 1 second (FEV1) 32%, and peak expiratory flow (PEF) 31% in Group B and FVC 17%, FEV1 17%, and PEF 5% in Group R) (P 0.05). Concentrations of bupivacaine and ropivacaine were below toxic levels rather than "normal range." We conclude that pulmonary function decreased more after IBP with 0.33% bupivacaine than with 0.33% ropivacaine

On multiple epistemologies of secularism: Toward a political economy critique

The chapter has three main parts, the first of which sets out with the introduction of a dyadic category of secularism questioning the dominant paradigm that views secularism as a Western cognitive type. The category in question is built up for a different paradigm by a political economy approach that analyzes the emergence of liberal capitalist world-economy, and the due institutional, political, and social processes. The second part contextualizes secularism in the parameters of neoliberal global capitalist world-economy and its postmodern, neoconservative political hegemony to offer a different context and to extend the previous historical analysis of the political economy of secularism to the contemporary phase. The third part traces the imperial logos critiqued by the Western left, and the (even unconsciously attended) misgivings of Western intellectualism due to an inherent Orientalism when it comes to the treatment of secularism in the Other. The third part also lays bare the particular necessities of the terrain on which the intellectuals in the periphery have to operate. All in all, the chapter seeks to uproot the persistent understandings of secularism and draw attention to the roots of secularism in political economy. © Springer Nature Switzerland AG 2020