21 research outputs found
Controlled electrochemical growth of ultra-long gold nanoribbons
No full textCitation: Basnet, G., Panta, K. R., Thapa, P. S., & Flanders, B. N. (2017). Controlled electrochemical growth of ultra-long gold nanoribbons. Applied Physics Letters, 110(7), 5. doi:10.1063/1.4976027This paper describes the electrochemical growth of branchless gold nanoribbons with similar to 40 nm x similar to 300 nm cross sections and >100 mu m lengths (giving length-to-thickness aspect ratios of > 10(3)). These structures are useful for opto-electronic studies and as nanoscale electrodes. The 0.75-1.0V voltage amplitude range is optimal for branchless ribbon growth. Reduced amplitudes induce no growth, possibly due to reversible redox chemistry of gold at reduced amplitudes, whereas elevated amplitudes, or excess electrical noise, induce significant side-branching. The inter-relatedness of voltage-amplitude, noise, and side-branching in electrochemical nanoribbon growth is demonstrated. Published by AIP Publishing
Fabrication of Tungsten Tips Suitable for Scanning Probe Microscopy by Electrochemical Etching Methods
No full textThe fabrication of metal tips is becoming an interesting field for scientists who are working in spectroscopy measurements. A significant amount of work has already been done in the tips fabrication process. Metal tips used to analyze the surface of materials play a key role in the scanning tunneling microscope (STM) technique. It\u27s remarkable quality that it is used to study the surface of material at the atomic level.
There are various methods used in the tips fabrication process. Of diverse methods, three different electrochemical etching methods: submerged method, single lamella drop-off method, and double lamella drop-off method are commonly used to make various tips\u27 shapes such as smaller cone shape, larger cone shape, sharp cone shape, and extremely sharp cone shape at room temperature are reported in this thesis. With submerged method, we made various tips in different etching parameters. The bulk surfaces of the etched tips were characterized using a simple optical microscope. Various tips shapes affected by etching parameters are discussed in this thesis. To better control tips\u27 shapes, a single lamella method was used. However, the tips still etched when the lower part of the etching wire dropped because there was no auto cutoff etching circuit at the end of the etching process. Sometimes, this method produced non-cone shapes tips. To overcome this problem, a double lamella drop-off method was finally used. In this method, the various tips\u27 shapes were made by the variation of the etchant height from the upper mark of the etch stop on the etching tungsten wire. The etch stop was enough to control the tips\u27 shapes. The fabricated tips through various etching methods are recommended to study the surface of material in the STM chamber
Studies on the Oxyurid parasites of Reptiles
No full textThe Oxyurid parasites of Reptiles form a group of very interesting forms and have been a subject of study by several distinguished helminthologists from early times. The earliest account, in a connected form, to which the writer has been able to refer is that given by Rudolphi (1819). This author, though recognising the genus Oxyuris, restricts to it the forms found in mammals and more particularly Oxyuris vermicttlaris from the large intestine of man and Oxyuris curvula from the caxum of horse; the Oxyurids of all other animals he refers to the genus Ascaris
Transplantation of healthcare financing policy from the United Kingdom to India
No full textThe staggering statistics in health conditions of India demand quick actions, and thus it is advised to come up with a solution which takes less time as compared to a complete design of a new system. This paper starts with background study of UK, Netherlands and Indian health care financing models, followed by an analysis ofeasibility of transplantation of financing policies from the UK to India. It is proved from literature survey that UK and Netherlands has one of the best financing models. Though Netherlands' model is also considered; but due toeconomic incompatibility of model in India, and UK's similar legislation background with India, UK's health care system is chosen to be analyzed further as a donor country in this case. A thorough study through Hofstede's cultural dimensions (Hofstede, Hofstede, and Minkov, 2010),family of nations, and actors pulling-in and goodness of fit perspectives study end with strategies of implementation to provide some recommendations for successful transplantation. The results of transplantation can be interpreted as "great example" (Rose, 1993) if the strategies of implementation are clearly kept in mind.Technology, Policy and Managemen
Fossil fuels, global warming and democracy: a report from a scene of the collision
No full textWhat happens to democracy when the fossil fuel industry collides with global warming?
Introduction
Democracy is caught in a collision between two forces: the need to respond to global warming by cutting carbon emissions, and the demands of the fossil fuel industry to increase carbon use and production. This is a slow motion collision that will take decades to conclude, though its ending seems inevitable: coal, and then oil and natural gas, will be replaced by more sustainable energy sources, but only after great damage to the environment.
In this paper I explore the question, What happens to democracy when the fossil fuel industry collides with global warming?
This collision is already making its marks on democratic practices. The fossil fuel industry is using every tool it can to preserve its wealth and power by pressuring governments, political parties, universities, regulators, courts, and voters. It is a process of tough, aggressive, and sophisticated politics that ultimately depends on denying the evidence that global warming poses a danger that needs to be urgently confronted.
Without a theoretical framework to focus this inquiry, it could easily produce little more than a list of anecdotes about politics and influence. The value of good theory is that it reveals the patterns in the evidence, showing how the disparate pieces are connected to one another, and to larger historical, social, and economic factors. In this paper, I drew theory from (among others) Valerie Bunce, Timothy Mitchell, and most importantly Terry Lynn Karl.
I use the work of these scholars to focus on the Canadian province of Alberta. Alberta provides an example of what can happen to democracy in places where fossil fuel production predominates. From time-to-time I link the paper to Australia, which depends even more than Canada on mineral extraction, and which is on the burning edge of global warming.
This paper should be read as a warning to people everywhere who are concerned about fossil fuel dependence, global warming, and democracy. Those who value democracy must ask, Can democracy as we know it survive global warming
A new blood fluke from an Indian tortoise, Trionyx gangeticus
No full textThe hermaphroditic Trematodes from the blood vessels of the turtles are included under the Family Spirorcbidae and represent several genera differing from each other in several features, including the general topography of the genital organs. It originally contained only two genera-Spirorchis and Hapalotrema, differing from each other in the number of suckers, the relative position of the genital glands and the number of testes. Owing to these unique differences between them they were referred by Stunkard (1921) to two subfamilies-Spirorchinae and Hapalotreminae. The work prior to 1923 is summed up by Stunkard (1923) in a brilliant memoir, where, besides describing two new genera, one under each of the two subfamilies, from North American turtles, he has clearly elucidated some important points of systematic nature. Subsequently, the same author has considerably added to our knowledge of the group in several memoirs mentioned in the list of references at the end of the present communication
On a new trematode of the genus Astiotrema looss, 1900, from the intestine of a Tortoise, Chitra indica
No full textLooss (1898) described a trematode, Distomum reniferum, from the intestine of a turtle, Trionyx nilotica. Later, while reviewing the genus Distomum of Retzius, 1782, the same author (1899) described a new form, Astia impleta, from the intestine of Tetrodon fahaka and also transferred his former species, Distomum reniferum as a type species of this new genus Astia. The generic name was subsequently changed to Astiotrema Looss, 1900 and both the species described originally under Astia are now included under this new name. Odhner (1911) redescribed both the species and added considerably to our account of these forms. Other species have since been added to the genus Astiotrema. The latest addition to our knowledge of the genus Astiotrema is that by Mehra (1931) who has given an interesting account of two new species from the tortoises of Allahabad, and has, besides, given a very useful table and key for the identification of the various species of the genus under review. The present paper deals with an account of another new species of the genus obtained at Lucknow, from the intestine of a tortoise, Chitra indica, from the river Gomti
Laser-Induced Electron Emission from Au Nanowires: A Probe for Orthogonal Polarizations
No full textPhotoelectron field emission, induced by femtosecond laser pulses focused on metallic nanotips, provides spatially coherent and temporally short electron pulses. The properties of the photoelectron yield give insight into both the material properties of the nanostructure and the exciting laser focus. Ultralong nanoribbons, grown as a single crystal attached to a metallic taper, are sources of electron field emission that have not yet been characterized. In this report, photoemission from gold nanoribbon samples is studied and compared to emission from tungsten and gold tips. We observe that the emission from sharp tips generally depends on one transverse component of the exciting laser field, while the emission of a blunted nanoribbon is found to be sensitive to both components. We propose that this property makes photoemission from nanoribbons a candidate for position-sensitive detection of the longitudinal field component in a tightly focused beam
Etch-stop method for reliably fabricating sharp yet mechanically stable scanning tunneling microscope tips
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