Modification of Hilbert's Space-Filling Curve to Avoid Obstacles: A Robotic Path-Planning Strategy

This paper addresses the problem of exploring a region using the Hilbert's space-filling curve in the presence of obstacles. No prior knowledge of the region being explored is assumed. An online algorithm is proposed which can implement evasive strategies to avoid obstacles comprising a single or two blocked unit squares placed side by side and successfully explore the entire region. The strategies are specified by the change in the waypoint array which robot going to follow. The fractal nature of the Hilbert's space-filling curve has been exploited in proving the validity of the solution

Crack suppression by natural fiber integration for improved interlaminar fracture toughness in fiber hybrid composites

In this paper, the effect of integration of natural fibers in UD carbon fiber is studied. The integration of natural fibers in carbon fiber is made via intra fiber hybridization. Natural fiber hybrid composite samples were prepared for Mode I and Mode II fracture tests. XRD analysis was done for the chosen natural fibres to know the crystallinity index and then compared with Carbon and Glass fibres. The fracture test experimental results, revealed that the effect of Jute fiber integration in UD Carbon epoxy composite was found significant in getting relatively good Mode I and II fracture toughness at the crack initiation without losing its stiffness. In addition to this Kenaf Carbon epoxy composite indicated better crack suppression with 30% higher propagation toughness values as compared other hybrid combinations and pristine composites. It is observed that integration of jute fibers in UD carbon epoxy composites was significant in achieving good mode I and mode II fracture toughness at the crack initiation without losing its stiffness and also kenaf carbon epoxy composites indicated better crack suppression with 30% higher propagation toughness as compared to other hybrid combinations used

Evidence-based national vaccine policy

India has over a century old tradition of development and production of vaccines. The Government rightly adopted self-sufficiency in vaccine production and self-reliance in vaccine technology as its policy objectives in 1986. However, in the absence of a full-fledged vaccine policy, there have been concerns related to demand and supply, manufacture vs. import, role of public and private sectors, choice of vaccines, new and combination vaccines, universal vs. selective vaccination, routine immunization vs. special drives, cost-benefit aspects, regulatory issues, logistics etc. The need for a comprehensive and evidence based vaccine policy that enables informed decisions on all these aspects from the public health point of view brought together doctors, scientists, policy analysts, lawyers and civil society representatives to formulate this policy paper for the consideration of the Government. This paper evolved out of the first ever ICMR-NISTADS national brainstorming workshop on vaccine policy held during 4-5 June, 2009 in New Delhi, and subsequent discussions over email for several weeks, before being adopted unanimously in the present form

Global wealth disparities drive adherence to COVID-safe pathways in head and neck cancer surgery

Peer reviewe

Matrix Hybridization Effects on Interlaminar Fracture Toughness of Glass Epoxy Laminates using Nano and Micro fillers

The composite materials are normally made of reinforcements and resins. High-performance composites are generally termed hybrid composite materials. Generally, fiber-reinforced composite laminates are very weak in their out-of-plane properties, to address this issue unidirectional (UD) Glass laminates are prepared by modifying epoxy matrix using plasma-treated multi-walled carbon nanotubes (MWCNTs) and compared with low-cost micro fillers like Aluminum oxide (Al2O3) and Sodium Carbonate (Na2CO3) in the epoxy matrix. All these Nano and Micro fillers were loaded in the range of 0.5wt% to 2wt% in epoxy. The addition of these fillers in the epoxy matrix was found to be effective in increasing the out-of-plane load-bearing capacity of the composites as compared to plain Glass epoxy laminates. Also, the fracture toughness enhanced in the range of 20-26% and 14-17.5% under mode I and mode II loading respectively. Scanning electron microscopic analysis was done for delaminated glass laminates and found that the delamination of fibers is the significant failure mechanism during crack initiation from the crack tip

Matrix Hybridization Effects on Interlaminar Fracture Toughness of Glass Epoxy Laminates using Nano and Micro fillers

The composite materials are normally made of reinforcements and resins. High-performance composites are generally termed hybrid composite materials. Generally, fiber-reinforced composite laminates are very weak in their out-of-plane properties, to address this issue unidirectional (UD) Glass laminates are prepared by modifying epoxy matrix using plasma-treated multi-walled carbon nanotubes (MWCNTs) and compared with low-cost micro fillers like Aluminum oxide (Al2O3) and Sodium Carbonate (Na2CO3) in the epoxy matrix. All these Nano and Micro fillers were loaded in the range of 0.5wt% to 2wt% in epoxy. The addition of these fillers in the epoxy matrix was found to be effective in increasing the out-of-plane load-bearing capacity of the composites as compared to plain Glass epoxy laminates. Also, the fracture toughness enhanced in the range of 20-26% and 14-17.5% under mode I and mode II loading respectively. Scanning electron microscopic analysis was done for delaminated glass laminates and found that the delamination of fibers is the significant failure mechanism during crack initiation from the crack tip