8 research outputs found
Electronic Design of an Analog Equalizer for a Bone Conduction Stethoscope
No full textAbstract
The necessity and interest of audiologists to finely tune and customize sound frequencies according to individual patient needs, has inspired us to develop and integrate an equalizer to a bone conduction stethoscope. The project designs an analog amplifier equalizer circuit that is used for volume control and frequency selection. It captures sounds from the skull bone with the help of a skin microphone hoping to provide audiologists a flexible tool that can isolate specific frequency bands for analysis, auditory experience diagnosis and troubleshooting of bone conduction hearing aids. The switching options designed on the equalizer has bandpass filters for the audiometric frequencies with the possibility to focus the listening range to both low and high frequencies and thereby encourage audiologists to select the desired ranges of inspection. The project plan was designed to use the electronic features to categorize audio spectrum into bass (125 Hz to 1 kHz), wide (125 Hz to 8 kHz) and treble (1-8 kHz) for testing. The test is done on two subjects with the use of a skin microphone having a strategy to check one’s own voice to understand the perception of booming effect, crispness and clarity along with normal speech auditory range of bone conduction voice. The test subjects also experimented by hearing each other’s voice through the equalizer to understand the audio spectrum as mimicked in normal hearing conditions as a reference. The results showed that the auditory experience was in sync with the theoretical expectations. To conclude, the design and testing of the prototype showed that it is a promising tool for audiologists in near future
Simulation and Optimisation of unsteady aerodynamic performance of a 2D VAWT rotor: With emphasis on airfoil design
No full textAirfoil design plays an important role in improving the performance of Vertical Axis Wind Turbines(VAWTs). The aim of this thesis is to arrive at optimal airfoil geometries to enhance the performance of VAWTs and analyse the performance of these optimal airfoils under steady and unsteady operation conditions of the rotor. The airfoil design is aimed at rotors operating in the Reynolds number range of 10ዀ. The inverse airfoil design approach is used to arrive at the airfoil geometries. The design process involves formulating a multiobjective optimisation problem with the aerodynamic and structural performance of the airfoil as objectives.After a comprehensive literature study, the objective derived by Ferreira and Geurts [25] was chosen for its suitability to the current work. The aerodynamic performance of the airfoil is gauged by the ratio of lift slope and drag coefficient. The structural objective is limited to the flapwise bending stiffness. To account for the weather impact, the aerodynamic objective also includes the effect of surface roughness. An effective optimisation framework is built with the Non-dominated Sorting Genetic Algorithm(NSGA-II) to arrive at the Pareto front with best suitable airfoils for VAWTs. This framework is coupled with XFOIL which evaluates the geometries and another python based framework, Distributed Evolutionary Algorithms in Python(DEAP) which helps in setting up the genetic algorithm. Once the convergence is reached, few airfoils from the final Pareto front are chosen for further analysis.Based on the literature study, the Actuator Cylinder Model(ACM) was chosen to simulate the performance of the airfoils in a VAWT rotor. The performance of the selected airfoils were analysed under steady flow conditions with the ACM. To account for the effects of unsteady flow over the airfoil, a Beddoes-Leishman type dynamic stall model formulated by the Risø national laboratories was integrated into the AC Model loop along with a correction to the effective angle of attack. The inviscid part of this model was validated with another AC Modelcode from Li [42] and the inviscid panel method 푈2퐷푖푉퐴 [65].The performance of the optimised airfoils is an improvement over the performance of the NACA airfoils of similar thicknesses which proves that the optimisation process has been successful. The performance of the airfoils in steady flow indicates that the power performance of the airfoil suffers more from the surface roughness as the thickness of the airfoil increases. The thicker airfoils perform better at high solidity applications at low tip speed ratios. The range of operational tip speed ratios decreases as the airfoils become thicker.The performance of these airfoils under the effects of unsteady flow under the inviscid flow assumption provides an overview of the differences in the performance of the airfoils under unsteady flow conditions. The range of tip speed ratios where the airfoils show their best performance moves towards higher values indicating that under unsteady flow effects, the rotor needs to operate at a higher rotational velocity to achieve its best performance. However, to obtain a better insight on the performances of the airfoil under unsteady flow effects, further studies with the complete validated Risø model have to be carried out.Aerospace Engineerin
Disaster Resilience in Vulnerable cities through Neighbourhood Development: A case of Chennai
No full textAbstractThis paper follows the discipline of Urban Design to elaborate the concepts of disaster resilience at the neighbourhood level for the collective development of Chennai city. The increased inflow and use of resources attributed to the growing urban population creates a pressure on the various natural systems, increasing their vulnerability to multiple attacks from natural and man-made forces. Hence the future adaptability of cities is important for its growth in the aftermath of a disaster strike. The intent of this research is thus to develop a framework of strategies for an emergency response programme and to develop a design scheme to make cities resilient, through neighbourhood development. A sample precinct of Chepauk was taken up for the design demonstration after a detailed analysis of the same, addressing various physical factors such as land use, open spaces, connectivity networks, physical and social infrastructure, built density, ecology and emergency response mechanism
A Study on Cost Effectiveness and Security of VANET Technologies for Future Enhancement
No full textAbstractIntelligent Transport System (ITS) is an advanced application which provides web enabled services for traffic and transport system, which results in a safer, coordinated traffic network system. ITS is very effectively used in VANET (Vehicular Ad-hoc Network), which is a spontaneous creation of wireless network of vehicles for exchanging information between them, for improved transport and traffic management and to enable various users to be sufficiently informed about the road and make safer and smarter decisions on road by using transport networks. As the technology has to be used widely, there is a high need for a low cost VANET technology with high security and Quality of Service. To go for any further developments, a thorough analysis on the available technologies is essential to get a closer view on the current scenario. The result of this study can open doors for a better technology for future VANETs. This paper considers a few existing technologies such as CROWN, Vehicular Cloud and VANET-Cloud and a comparison on these is carried out
Design of NEMS Based Intraocular Pressure Sensing System
No full textAbstractGlaucoma is one of the leading causes of irreversible blindness. The change in intraocular pressure (IOP) inside the anterior chamber of the eye beyond its normal limit leads to this condition which initially affects the peripheral vision and if left untreated, results in permanent blindness. Early detection of elevation in IOP helps to slow down the disease progress. Thus a highly precise, cost effective, miniaturized pressure sensor is an important need for sensing the IOP. In the present work, the piezoresistivity of Single Walled Carbon Nano Tubes (SWCNT) is exploited to design a diaphragm based Nano-Electro-Mechanical Systems (NEMS) pressure sensor. Finite Element Method simulation is then performed to find the change in resistance ofthe piezoresistive material. This change in resistance results a change in output voltage corresponding to the pressure applied, which can be measured by an interfacing circuitry consisting of a low voltage amplifier andlow power-high speed Analog to Digital Converter (ADC). The resultant pressure sensor response is found to be highly linear and its sensitivity can be increased by changing diaphragm dimensions
Development and charactersisation of MCP-1 and ɑ-MSH fused with elastin-like polypeptide nanoparticles to treat pressure ulcers caused by spinal cord injury
No full textPressure ulcers are a challenging complication seen in patients with spinal cord injury (SCI). They decrease the patients' quality of life and cause physical, social, and physiological burdens. There is a delay in skin wound healing after SCI, which we hypothesize is due to a decrease in the expression of chemokines and neuropeptides that recruit macrophages to the wound. In this study, we developed and characterized elastin-like polypeptide (ELP) nanoparticles incorporating the chemokine MCP-1 (MCP-ELP), and the neuropeptide a-MSH (a-MSH-ELP). These chemokines and neuropeptides are important for modulating the inflammatory phase of wound healing via recruiting different macrophages. The fusion protein approach of ELP conjugation is proven to deliver better bioavailability and enhance stability. For purification of fusion proteins, we used inverse transition cycling by exploiting the phase transitioning property of ELP. We obtained single purified bands in SDS-PAGE, with sizes ranging from ~200 nm to 350 nm for MCP-ELP and a-MSH-ELP, respectively. The stability test suggested that fusion nanoparticles and native proteins stayed stable in PBS for 7 days but degraded in elastase after day 0. To verify the bioactivity of the fusion proteins, a transwell migration assay was conducted with the monocyte-like cell line THP-1, which expresses receptors to both MCP-1 and a-MSH. THP-1 monocytes migrated significantly more in the presence of a-MSH-ELP vs a-MSH (p0.0004), and a non-statistically significant trend towards better proliferation compared with native MCP-1 (p=0.0748). a-MSH-ELP showed a trend of better proliferation, but the effect was not statistically significant. Human dermal fibroblasts and keratinocytes showed a trend of higher proliferation with 0.1 nM to 1 µM that was not statistically significant. In conclusion, we successfully developed, purified, and characterized MCP-ELP and a-MSH-ELP. Both have biological activities in vitro that are equal to, and sometimes even better than, the native proteins, and could advance to in vivo testing.M.S.Includes bibliographical reference
Playing Action Video Games a Key to Cognitive Enhancement
No full textAbstractIn this paper, we aim to analyse the impact of training on improvement in cognitive abilities and performance of the subjects playing single player action video game. Recent research indicates that playing Action video games improve cognitive abilities. However no study has exploited the novel technique, Empirical Mode Decomposition in the field of action video games. Empirical mode decomposition was used to extract various features by decomposing EEG data into intrinsic mode functions. Intrinsic mode functions were used to calculate linear features like standard deviation, phase and energy. K- Nearest Neighbour & Linear Discriminant Analysis classifiers were used to classify the subject based on the changes in features extracted due to the impact of training. Psychological tests conducted before and after the training, positively affirm that training improves cognitive abilities like reaction time and reduces stress level
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Examining Gender Representation in US News and World Report Top 25 Urology Departments: Female Faculty Hold Lower Professorial Levels and Publication Rates Than Male Counterparts
No full textTo examine female representation in US News and World Report (USNWR) top 25 US Urology departments and identify trends of female representation in institutional roles.
Using the 2022 USNWR, we collected data from each institution's websites along with a compared geographically local cohort to evaluate the presence of female residents, female attendings, and professorial levels. First or last author faculty publications numbers were found using PubMed and Scopus in fiscal year 2022.
The top 25 institutions averaged ~32.3% female residents and 18.7% female attendings, which was not significantly different from the comparison cohort. Of the total publications of fiscal year 2022, female attendings contributed ~14% (p < 0.001), also not significantly different from the comparison cohort. Only 20.4% of listed female attendings in top 25 programs are full Professors, compared to 41.1% of the listed men (p < 0.05). The most common level of female professorship is Assistant Professor (53.4%). Level of female professorship between cohort was significantly different, with female urologists more likely to hold a title of full Professor in the top 25 cohort compared to the nontop 25 cohort regardless of similar publication output (p < 0.05).
Female faculty in Urology continue to be underrepresented in the top Urology departments, with significant difference in equitable female professorship appointments between top 25 and nontop 25 departments. Future directions include examining the impact of early mentorship and sponsorship on representation over time
