1,720,954 research outputs found
Cognitive Enhancement Using Odor as Intervention
No full textME, EIEDBrain is the most sophisticated part of the human body. We concentrate our research on how to enhance the abilities of a healthy brain. The science dealing with this concern is called cognitive science. Cognitive assessment is a formal assessment of an individual’s abilities in a range of areas such as verbal and non-verbal skills, memory and speed of processing. The research assesses the cognitive abilities through videos. The study examined and analyzed the electroencephalographic signals of various individuals acquired while the individual is made to go through distinguished emotions- happy and sad. The subject is made to watch two different videos related to happy emotions and sad emotions. The pilot study involves 10 healthy engineering students on whom tests are carried out. The intervention used in this research is odor of lemon. The subjects were exposed to the odor for one hour daily for 15 days. Cognitive Enhancement, i.e., advancement or betterment of mental abilities, is initiated with assessing cognitive abilities. As a part of pre-recording, the ElectroEncephaloGraphy (EEG) signals are acquired while the person watches the videos. During the intervention part, the subject is exposed to odor and lastly, during post-recording the EEG signals are acquired again while the subject watches videos. Analysis of both pre and post-recording signals is done using MATLAB (EEGLAB, Discrete Wavelet Transform) and comparison of various features of both recordings is done. The comparison is done by calculating asymmetry indices and energies of different bands of physiological EEG signals. It is found that asymmetry indices are improved in case of happy emotions as compared to the sad ones which become even sadder. Hence, making an individual emotionally sensitive
Thin Film Based Gas Sensor for Diabetes Mellitus Applications
No full textDiabetes or diabetes mellitus is a group of metabolic diseases in which the level of glucose rises in the human body. This disease results from imperfections in insulin secretion or insulin action in the body. Diabetes can be very dangerous and may even lead to long term damage, non-functioning of organs like heart, kidney and blood vessels. Detection of such a disease is very essential for early treatment. People have been monitoring the glucose level through blood by means of invasive methods. On the contrary, breath analysis has gained recent interest for detection of diabetes. Acetone has been stated to be the biomarker for diabetes mellitus. Breath analysis is a non-invasive method which can be used to detect acetone levels in human breath. For a healthy individual, the level of acetone in breath is less than 0.8 ppm, while it ranges from 1.7 ppm to 3.7 ppm for a diabetic individual. Acetone in breath is found due to the excess formation of ketone bodies in the human body.
For detection of diabetes through breath, a very low concentration of 1.7 ppm had to be detected in breath. For this purpose, metal oxide thin films had been considered. A metal oxide gas sensor can be of high importance for the same, since it has been proven that the resistance/electrical conductivity of metal oxides varies when the concentration of surrounding gas changes. MEMS technologies had been used to develop a miniaturized thin film based gas sensor. Four metal oxide thin films, viz., tungsten dioxide (WO2), tungsten trioxide (WO3), tin dioxide (SnO2) and tin-doped tungsten oxide (Sn-doped WO3) were investigated to find the best for detection of acetone gas.
After standard cleaning procedure of n-type silicon wafers, a 1 m thick layer of silicon dioxide (SiO2) was deposited over them by means of thermal oxidation. 100 nm thin layer of each WO2, WO3, SnO2 and Sn-doped WO3 were deposited over four different oxidized silicon wafers by means of reactive ion sputtering technique. For deposition of WO2, the ratio of argon gas to oxygen gas was kept to be 80:20. In case of WO3 deposition, the ratio was set as 70:30. Both WO2 and WO3 were annealed at an optimum annealing temperature of 500oC for one hour each. For SnO2 deposition, the ratio was set to be 60:40. This SnO2 film was annealed at 300oC for one hour. For deposition of Sn-doped WO3, a thin layer (1-2 nm) of tin was sputtered over WO3 and this was then diffused in WO3 by annealing at an elevated temperature of 400oC for one hour. The optimum annealing temperatures for each film were analyzed at which the film gave maximum response percentage towards acetone gas. Each wafer was then diced into multiple 5 mm x 5 mm chips. These chips were wire bonded using conducting epoxy at two points for carrying out the measurements. Gas sensing procedure employing the setup elements, viz., computerized gas mixture to mix acetone and dry air to achieve the desired concentration, gas sensing chamber, external heater, picoammeter, voltmeter, etc. was used to find the best film out of four, i.e., SnO2 was found and this was then employed in development of complete micro gas sensor using the fabrication steps.
The micro gas sensor of miniature size 2.5 mm x 2.56 mm consisted of three primary elements, viz., the micro heater, the interdigitated electrodes (IDEs) and the sensing film (SnO2). The n-type silicon wafer was first cleaned using inorganic and organic cleaning techniques, followed by thermal growth of 1 m thick SnO2. Backside etching of silicon was done after the photolithography of cavity to be opened using TMAH etching. A cavity of size 1100 m x 1100 m which ended up to around 700 m x 700 m was developed to reduce power losses. Photolithography for micro heater was done on the front side of the wafer and DC sputtering technique was used to develop a platinum heater of thickness 200 nm, followed by lifting-off of excess platinum from the wafer. A passivation layer of silicon nitride (Si3N4) of thickness 0.6 m was deposited using PECVD technique to provide isolation between the micro heater and IDEs. Platinum IDEs of thickness 1300 angstroms were patterned using photolithography and were sputtered using DC sputtering technique over the passivation layer. Lastly, photography for sensing film was done and reactive ion sputtering was used to deposit 100 nm of SnO2 as sensing film. This device was then wire bonded to a TO header. Instrumentation of the developed sensor was done and voltage divider circuitry, current pump circuitry and read out circuitry were formed for displaying the initial and final resistance values (before and after exposure to acetone gas) on the display screen.
All four sensing films, viz., WO2, WO3, SnO2 and Sn-doped WO3 were characterized using various techniques like XRD, SEM and AFM. The XRD patterns of tungsten oxide thin films revealed the formation of orthorhombic phase of WO2 and hexagonal phase of WO3. The other films depicted reflections of orthorhombic phase of tin (IV) oxide (SnO2) and Sn-doped WO3 resembling reflections of Sn and WO3. The topography of sensing film was characterized using AFM and SEM. The surface morphology of the thin film was seen by this method. The grain sizes and roughness had also been computed. Each sensing film was exposed to different concentrations of acetone gas and the record of resistance changes was maintained. Response percentages corresponding to various concentrations of acetone gas were computed. Optimum operational temperature for each sensing film was computed as 260oC for WO2, 220oC for WO3, 360oC for SnO2 and 300oC for Sn-doped WO3. Very low concentration of acetone gas, i.e., 1.5 ppm was detected by SnO2 with good percentage response of 30 %. Sn-WO3 could detect a low acetone concentration of 3 ppm but with a low response percentage of 0.6 %. WO2 and WO3 could detect a minimum acetone gas concentration of 10 and 15 ppm with response percentages 15 % and 17 %, respectively. Hence, SnO¬2 was chosen to be the best of all for detection of acetone gas with a minimum concentration of 1.5 ppm. Interfering gases like ethanol, carbon dioxide and benzene were also tested on SnO2 and it was observed that at an optimum operational temperature of 360oC, SnO2 responds the best to acetone gas
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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