Homeless man fatally spears bear in Anchorage

first_imgA homeless man fashioned a long knife to a groomed tree branch and speared a hungry black bear cub that was sniffing for food Friday morning at an illegal camp site in Anchorage.State wildlife biologist Dave Battle says a sow and yearling have been stealing food from the homeless camp for days. The cub was near a tent Friday morning, and a man in the camp was afraid it would attack.Alaska State Troopers spokeswoman Beth Ipsen says in an email the man earlier fashioned a long knife to a “nicely groomed branch.” Battle says the man threw the spear, hitting the bear in the side. The bear ran less than 20 yards before collapsing and dying.Ipsen says David Tandler was given a $310 citation for negligent feeding of wildlife.last_img

Blown Bubble Method Disperses Nanostructures Over Large Areas

first_img Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Researchers from Harvard University and the University of Hawaii at Manoa recently announced a new method for organizing nanowires and carbon nanotubes across large areas: blowing bubbles. Bubble blowing, or blown-film extrusion, is a well developed technique used in industry, such as in plastic-film manufacturing, where polymers are melted and inflated into balloons that can be collapsed and cut. However, this is the first time that this approach has been used in nanoscience research. The scientists suspended each type of nanostructure in a polymer-based liquid and created large bubbles using a circular die and controlled pressure. The very thin wall of each bubble (a few hundred nanometers thick) contains an even, well organized and aligned distribution of nanostructures. When an expanding bubble is placed against a surface, the bubble wall is transferred to it. This allows a thin film with a controllable nanostructure density and pattern to be deposited onto relatively large wafers, plastic sheets, and curved surfaces.“This ability is necessary for many proposed optical and electronic applications for nanowires and nanotubes but, so far, other methods cannot be extended to the large-scale assembly of nanowires and nanotubes on both flexible and rigid substrates,” said Harvard scientist Charles Lieber, the paper’s corresponding author, to PhysOrg.com.Lieber and his colleagues worked with two types of nanowires – silicon and cadmium sulfide – and both single- and multi-walled carbon nanotubes. In each case, they were able to produce bubbles with diameters greater than 25 centimeters (cm) and heights greater than 50 cm. The films were transferred to various surfaces: a silicon wafer 20 cm in diameter, a flexible plastic sheet with dimensions of 22.5 cm x 30 cm, and a half cylinder 2.5 cm in diameter and 6 cm long.The researchers say that by using larger dies and learning how to gain greater control of the expansion process they could potentially create bubbles up to a few meters in dimension as is achieved in today’s plastic-film industry. This means that films larger than one meter across could be produced and transferred, opening up the potential of new large-area electronics applications using nanowires and nanotubes.Lieber and his colleagues illustrated this potential by using a silicon-nanowire blown-bubble film to create a large array of nanowire-based transistors on 7.5-cm-diameter plastic sheets. The transistors’ properties and performance compare to, and often exceed, those created using other assembly methods. By using higher performance nanowires, the scientists expect that significant improvements are possible.“Our method has the added advantage of being a more straightforward and efficient approach than other techniques in terms of making functional nanodevices over large areas,” said Lieber.The scientists do concede that the nanowire density and wire-to-wire distance of the silicon-nanowire film currently achieved are “modest,” but can be further increased by preparing a higher concentration polymer suspension of nanostructures. However, they say, those values are still useful for some applications, such as biological sensor arrays and display screens.This research is discussed in the May 27 online edition of Nature Nanotechnology.Citation: Guihua Yu, Anyuan Cao and Charles M. Lieber, Nature Nanotechnology, 2007, 2, 372-377.Copyright 2007 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com. Citation: ‘Blown Bubble’ Method Disperses Nanostructures Over Large Areas (2007, June 22) retrieved 18 August 2019 from https://phys.org/news/2007-06-blown-method-disperses-nanostructures-large.html New technology gives insight into how nanomaterials form and grow A blown-bubble film (bubble diameter is 35 cm, height is 50 cm) that has coated the surface of two silicon wafers. Credit: Charles Lieber, et al.last_img read more

Abstract is beautiful

first_imgArtist Puneet Kaushik presents his latest series of works titled Daraar – Beneath the Faultline at India Art Fair from January 29 to February 1. The works reflect no longer something remote, but abstractions of life itself. Kaushik’s bodies of work are aesthetic and material dimensions of extractions, accumulation, territorialisation, condensations and fractures underlying the visible reality of urban life. They are neo-expressionist, collages of kaleidoscope materials and techniques – wire mesh, paint, bead work, carpet craft, line drawings and organic dyes that bring to the surface histories of tension that exist just beneath the ordinariness of everyday lived humanity.  Also Read – ‘Playing Jojo was emotionally exhausting’Known for using methodologies and traditional techniques incorporating tribal and folk art like the works are of steel wire mesh, woven hibiscus and coffee stains on paper, natural dyes, tufting the carpet technique, dabkha and bead work.In his works, Puneet has been successfully driven by a single idea or concept, injecting an element of exploration, with materials offering their own guiding agency; and in this respect he marks a posture of difference. Also Read – Leslie doing new comedy special with NetflixThe guiding concept behind the majority of the works has been around the idea of Identity, the dealing with the self. The beauty and the ugliness within the surface; the superficial and the deeper self, textured and layered by different circumstances where it is rare to be in a position to penetrate into the real self.Puneet has been intrigued by age-old traditional techniques like knitting, crochet and embroidery, rooted deep in our cultures as a means of talking about the self. For example, the traditional Tibetan technique using a process of embroidery where two or more beads are stitched in one go was normally done not only to enhance the jewellery or crown but also to thicken the surface in order to protect and keep one warm.When: January 29 to February 1Where: Booth S-5, India Art Fair, NSIC Exhibition Groundslast_img read more

Four hurt as concrete chunk falls off at CMCH

first_imgKolkata: Four persons were injured when a concrete chunk from a roof of a building inside Calcutta Medical College and Hospital (CMCH) fell offon Friday. The incident took place at the Regional Institute of Ophthalmology department of the hospital in the morning. According to hospital sources, the concrete chunk fell on the relatives of the patient, who were waiting outside the operation theater in the eye department. The incident occurred when an operation was going on inside the operation theater. After being informed the security personnel of the hospital rushed to the spot and brought the situation under control. The hospital authorities claimed that the incident had no impact on the operation. Also Read – Rain batters Kolkata, cripples normal lifeAccording to the hospital, the patients’ relatives were not seriously injured. Some of the victims had, however, received head injuries. They were immediately taken by the hospital staff and attended by doctors. The incident triggered tension among patients visiting the eye department of the hospital and their family members. The patients’ relatives were immediately removed from the place and the entire area was cordoned off to avoid any further incident. It was learnt from hospital sources that renovation works were carried out by the Public Works of Department in the Ophthalmology department recently. The hospital authorities are probing into the incident and figuring how it took place despite the repair works. All the injured victims are stated to be stable. A probe has been initiated.last_img read more