654 research outputs found
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Estimation of tunneling effect caused by luminance non-uniformity in head-up displays
No full textHead-up displays (HUDs) enable a pilot to manage aircraft activities by facilitating simultaneous access to the flight instrument data and to the outside scene. However, HUDs can also distract a pilot. This study shows that HUD luminance non-uniformity may force inappropriate distribution of attention between the events shown on HUD symbology and the outside scene because of the resultant differential contrast in the display area. Results of statistical analysis demonstrate considerable effects of HUD image luminance and ambient luminance, as well as their interaction, on the detection of events displayed on an HUD and the outside scene
Attention Tunneling: Effects of Limiting Field of View Due to Beam Combiner Frame of Head-Up Display
No full textHead-up displays (HUDs) have become an integral
part of the fighter aircraft and are now becoming increasingly popular in various nonmilitary sectors also. It enhances the pilot’s performance by providing him with all of the flight, aircraft, target, and weapon data in collimated fashion superimposed on his forward
view. The collimation of HUD symbology and infrared raster image removes requirement of refocusing eyes on outside events. However, there are attention capture and cognitive tunneling issues related with usage of HUD in aircraft. In this paper, effect of obstruction due to beam combiner frame in form of misaccommodation,
misconvergence, and limited horizontal field of view (FOV) on attention capture of aircraft pilot has been presented. While the beam combiner frame is necessary to hold wavelength selective glasses, they provide obscuration in forward view of pilot in both, total field of view (TFOV) as well as instantaneous field of view
(IFOV). Angle of combiner frame structure and its width present different degrees of obscuration to the pilot within the head motion box (HMB). These limitations cause inappropriate distribution of pilot’s attention on outside events and aircraft events, as he has to
adjust his head position to view the obscured part of outside world. This forces him to focus his attention more on outside events which may make him miss some event on HUD symbology. The study and experimental results have been presented in detail to corroborate this fact
Parametric optimization and design validation based on finite element analysis of hybrid socket adapter for transfemoral prosthetic knee.
No full textBACKGROUND:
Finite element analysis has been universally employed for the stress and strain analysis in lower extremity prosthetics. The socket adapter was the principal subject of interest due to its importance in deciding the knee motion range.
OBJECTIVES:
This article focused on the static and dynamic stress analysis of the designed hybrid adapter developed by the authors. A standard mechanical design validation approach using von Mises was followed. Four materials were considered for the analysis, namely, carbon fiber, oil-filled nylon, Al-6061, and mild steel.
STUDY DESIGN:
The paper analyses the static and dynamic stress on designed hybrid adapter which incorporates features of conventional male and female socket adapters. The finite element analysis was carried out for possible different angles of knee flexion simulating static and dynamic gait situation.
METHODS:
Research was carried out on available design of socket adapter. Mechanical design of hybrid adapter was conceptualized and a CAD model was generated using Inventor modelling software. Static and dynamic stress analysis was carried out on different materials for optimization.
RESULTS:
The finite element analysis was carried out on the software Autodesk Inventor Professional Ver. 2011. The peak value of von Mises stress occurred in the neck region of the adapter and in the lower face region at rod eye-adapter junction in static and dynamic analyses, respectively.
CONCLUSIONS:
Oil-filled nylon was found to be the best material among the four with respect to strength, weight, and cost.
CLINICAL RELEVANCE:
Research investigations on newer materials for development of improved prosthesis will immensely benefit the amputees. The study analyze the static and dynamic stress on the knee joint adapter to provide better material used for hybrid design of adapter
Investigation on nanoparticle distribution for thermal ablation of a tumour subjected to nanoparticle assisted thermal therapy
No full textThis study investigates the effect of the distribution of nanoparticles delivered to a skin tumour for the thermal ablation conditions attained during thermal therapy. Ultimate aim is to define a distribution of nanoparticles as well as a combination of other therapeutic parameters to attain thermal ablation temperatures (50–60 °C) within whole of the tumour region. Three different cases of nanoparticle distributions are analysed under controlled conditions for all other parameters viz. irradiation intensity and duration, and volume fraction of nanoparticles. Results show that distribution of nanoparticles into only the periphery of tumour resulted in desired thermal ablation temperature in whole of tumour. For the tumour size considered in this study, an irradiation intensity of 1.25 W/cm2 for duration of 300 s and a nanoparticle volume fraction of 0.001% was optimal to attain a temperature of ≥53 °C within the whole tumour region. It is concluded that distribution of nanoparticles in peripheral region of tumour, along with a controlled combination of other parameters, seems favourable and provides a promising pathway for thermal ablation of a tumour subjected to nanoparticle assisted thermal therapy
Styrene Sulphonic Acid Doped Polyaniline Based Immunosensor for Highly Sensitive Impedimetric Sensing of Atrazine
No full textStyrene sulphonic acid (SSA) doped polyaniline (PAni) was chemically synthesized. The synthesized product SSA-PAni was treated with 3-(aminopropyl) triethoxysilane in order to achieve a functional terminal of −NH2 group. This functional nanopolymer has been electrochemically deposited on to the working area of a carbon screen printed electrode (carbon SPE). Incubation of the SSA-PAni modified carbon SPE with anti-atrazine antibodies yielded the formation of a pesticide immunosensor. This immunosensor offered specific and highly sensitive detection (limit of detection 0.01 ng/mL) of atrazine over a wide concentration range (0.01–50 ng/mL)
Graphene-gated biochip for the detection of cardiac marker Troponin I
No full textWe report lithium ion intercalation mediated efficient exfoliation of graphite to form monolithic graphene sheets which have subsequently been investigated for the development of highly sensitive label-free electrochemical detection platform for cardiac biomarker, Troponin I (cTnI). The spectroscopic and morphological analysis demonstrated the formation of defect free graphene sheets which were successfully employed to fabricate an inter-digited microdevice in a drain-source configuration on a silicon biochip. The graphene gated biochip functionalized with anti-cTnI antibodies used in label free detection of cTnI which exhibited an excellent sensitivity in the picogram range (~1 pg mL(-1)) for cTnI without the use of any enzymatic amplification that promises its potential applicability for bio-molecular detection in clinical diagnosis
Humidity Sensing Using Gelatin and Cobalt Chloride Coating on Indium Tin Oxide-Coated Long-Period Grating
No full textIn this article, humidity sensing using gelatin and cobalt chloride on indium tin oxide coated long-period gratings was proposed and demonstrated. First, a thin overlay of indium tin oxide was deposited on a long-period grating by using a simple dip coating methodology. Similarly, a combination of gelatin and cobalt chloride was deposited onto the indium tin oxide layer. A field emission scanning electron microscope provided detailed evidence of the attachment of amalgamation on long-period gratings. The designed sensor showed a significant shift in the resonance wavelength when the relative humidity varied from 40% to 95%, with a sensitivity of 0.12 nm/% relative humidity and an accuracy of 98.45%
Sensitive Detection And Quantification Of Pathogenic Bacteria Using Fluorescence Based Optical Technique
No full textNature of bacterial infections and the influence of pathogenic bacteria on cells are of critical interest to researchers in microbiology, medicine and drug design. Detection, identification and quantification of such pathogenic bacteria in a shortest time is a major requirements in food and healthcare sectors. Foodborne diseases are primarily caused by various pathogenic micro-organism. It has been known that enterohemorrhagic Escherichia coli (EHEC) and enteropathogenic Escherichia coli (EPEC) are important human pathogens that cause persistent diarrhea, especially in young children. Enterohemorrhagic E-coli O157:H7 is one of the most dangerous pathogen causes disease that may lead to death. The bacterial growth is multiplexing in time and hence there is a need for replacing the traditional methods by rapid sensing one. Fluorescence based optical sensing is one of the rapid sensing method and the sensor which we developed has the sensitivity to detect the E-coli bacteria in the range from 105 cells/ml to 109 cells/ml. The sensitivity limit of 105 cells/ml has been arrived and the results are in comparison with the standard Perkin-Elmer Fluorimeter. Moreover it exhibited a good repeatability, reproducibility and stability
Surface Roughness and Profile Error in Precision Diamond Turning of C18000
No full textNickel–silicon–chromium–copper (C18000) alloy is widely used for many precision applications due to its high thermal conductivity, hardness, and moderate strength in fabrication of parts of molds. This study was carried out on this material for achieving mirror finish and minimizing profile error. Four machine and tool parameters were varied at different levels in a single point diamond turning operation to create a spherical profile on the workpiece. The surface roughness and profile accuracy were significantly affected by tool nose radius, feed rate, and spindle speed and depth of cut had insignificant effect. The process was optimized separately for both surface roughness and profile accuracy. Increased tool nose radius caused a ripple like effect on the machined surface as compared to a digging effect with low or no tool nose radius and thus showed a better surface finish. The profile error, however, increased with tool nose radius. Subsequently, both surface roughness and profile accuracy were optimized together using grey relational grade to obtain a globally optimized solution. The final parameter setting in an optimal solution identified feed rate as the most significant parameter followed by nose radius and spindle speed. A surface roughness and profile error of 15 nm and 0.464 µm, respectively, was attained during the confirmation experiments