3,768 research outputs found
Surface morphological evolutions on single crystal films by strong anisotropic drift-diffusion under the capillary and electromigration forces
The morphological evolution of voids at the unpassivated surfaces and the
sidewalls of the single crystal metallic films are investigated via computer
simulations by using the novel mathematical model developed by Ogurtani relying
on the fundamental postulates of irreversible thermodynamics. The effects of
the drift-diffusion anisotropy on the development of the surface morphological
scenarios are fully explored under the action of the electromigration (EM) and
capillary forces (CF), utilizing numerous combination of the surface textures
and the directions of the applied electric field. The interconnect failure time
due to the EM induced wedge shape internal voids and the incubation time of the
oscillatory surface waves, under the severe instability regimes, are deduced by
the novel renormalization procedures applied on the outputs of the computer
simulation experiments.Comment: 41 pages, 18 figures. related simulation movies utilizing numerous
combination of the surface texture, see
http://www.csl.mete.metu.edu.tr/aytac/thesis/movies/index.ht
Evaluation of a Behind-the-Ear ECG Device for Smartphone based Integrated Multiple Smart Sensor System in Health Applications
In this paper, we present a wireless Multiple Smart Sensor System (MSSS) in conjunction with a smartphone to enable an unobtrusive monitoring of electrocardiogram (ear-lead ECG) integrated with multiple sensor system which includes core body temperature and blood oxygen saturation (SpO2) for ambulatory patients. The proposed behind-the-ear device makes the system desirable to measure ECG data: technically less complex, physically attached to non-hair regions, hence more suitable for long term use, and user friendly as no need to undress the top garment. The proposed smart sensor device is similar to the hearing aid device and is wirelessly connected to a smartphone for physiological data transmission and displaying. This device not only gives access to the core temperature and ECG from the ear, but also the device can be controlled (removed and reapplied) by the patient at any time, thus increasing the usability of personal healthcare applications. A number of combination ECG electrodes, which are based on the area of the electrode and dry/non-dry nature of the surface of the electrodes are tested at various locations near behind the ear. The best ECG electrode is then chosen based on the Signal-to-Noise Ratio (SNR) of the measured ECG signals. These electrodes showed acceptable SNR ratio of ~20 db, which is comparable with existing tradition ECG electrodes. The developed ECG electrode systems is then integrated with commercially available PPG sensor (Amperor pulse oximeter) and core body temperature sensor (MLX90614) using a specialized micro controller (Arduino UNO) and the results monitored using a newly developed smartphone (android) application
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Ear-Lead Multiple Smart Bio Sensor System in M-health
In this paper, we present a multi-parameter wearable sensor system within a smartphone to enable a real-time unobtrusive monitoring of core body temperature, electrocardiogram (ear-lead ECG), and blood oxygen saturation (SpO2) on ambulatory patients. Clinical researches illustrating that continuing accurate measurements of core body temperature are crucial to investigate human thermoregulation in ambulatory environment and during activity. On the other part, ECG remains the mainstay test for primary diagnosis and survival analysis of the heart diseases. We implement a wireless multisensory system that measures both the tympanic temperature inside the ear and ECG data from an ear and an arm. The behind-the-Ear device makes desirable to measure ECG data without any chest belt and allow patient move around freely. The proposed Bluetooth device has similarity the form factor of a hearing aid and is wirelessly connected to a smartphone for data transmission and displaying. This device not only gives the doctors access to the core temperature and ECG data in real time, but the device can be controlled – removed and reapplied – by the patient at any time, thus increasing the performance of personal health applications
Graphene-Enabled Electrodes for Electrocardiogram Monitoring
The unique parameters of Graphene (GN), notably its considerable electron mobility, high surface area and electrical conductivity are bringing extensive attention into the wearable technologies. This work presents a novel Graphene-based electrode for acquisition of electrocardiogram (ECG). The proposed electrode was fabricated by coating GN on top of metallic layer of Ag/AgCl electrode using chemical vapor deposition (CVD) technique. To investigate the performance of the fabricated GN-based electrode, two types of electrodes were fabricated with different sizes to conduct the signal qualities and the skin-electrode contact impedance measurements. Performances of the GN-enabled electrodes were compared to the conventional Ag/AgCl electrodes in terms of ECG signal quality, skin-electrode contact impedance, signal-to-noise ratio (SNR) and response time. Experimental results showed the proposed GN-based electrodes produced better ECG signals, higher SNR (improved by 8%) and lower contact impedance (improved by 78%) values than conventional ECG electrodes
Nutrient contents and in vitro digestibility of different parts of corn plant
AbstractThe objective of this study was to assess the nutrient contents and in vitro true digestibility (IVTD) of parts of the corn plant. The corn used in the study was P2088, a variety that is grown widely in Turkey. It had matured and was harvested 140 days after planting. Four replicate plants were separated into nine parts, namely lower stalk, central stalk, upper stalk, corn ear stalk, corn ear shuck, kernels, corn cob, leaf, tassel, plus the entire plant. The samples were dried and ground for analysis. Nutritional values were determined in the laboratory and in vitro digestibility was assessed. Significant differences in nutrient content were observed among parts of the corn plant. The highest crude protein (CP) content was found in the leaf (12.41%), followed by the grain (12.37%). Dry matter (DM) varied from 91.25% to 96.07%. The highest ether extract (EE) was in the grain (2.84%), and the upper stalk contained the least EE (0.29%). The parts also differed in their contents of crude cellulose (CS) and crude ash (CA) (P <0.001). Most organic matter (OM) was found in the corn cup (94.27%). The highest in vitro dry matter digestibility (IVDMD) was in the kernels (79.06%) and the lowest was in the lower stalk (38.13%). In terms of in vitro true organic matter digestibility (OMD) values of the corn plant and its 9 parts, the highest values were found in the kernels and the lowest in the lower stalk.Keywords: crude nutrients, in vitro true digestibility, parts of corn plan
Influence functions of trimmed likelihood estimators for lifetime experiments
We provide a general approach for deriving the influence function for trimmed likelihood estimators using the implicit function theorem. The approach is applied to lifetime models with exponential or lognormal distributions possessing a linear or nonlinear link function. A side result is that the functional form of the trimmed estimator for location and linear regression used by Bednarski and Clarke (1993, 2002) and Bednarski et al. (2010) is not generally always the correct functional form of a trimmed likelihood estimator. However, it is a version for which the influence function has a treatable form. A real data example shows the effect of trimming using a nonlinear link function for either the exponential or lognormal distribution
Influence functions of trimmed likelihood estimators for lifetime experiments
We provide a general approach for deriving the influence function for trimmed likelihood estimators using the implicit function theorem. The approach is applied to lifetime models with exponential or lognormal distributions possessing a linear or nonlinear link function. A side result is that the functional form of the trimmed estimator for location and linear regression used by Bednarski and Clarke (1993, 2002) and Bednarski et al. (2010) is not generally always the correct functional form of a trimmed likelihood estimator. However, it is a version for which the influence function has a treatable form. A real data example shows the effect of trimming using a nonlinear link function for either the exponential or lognormal distribution
Kinematic landslide monitoring with Kalman filtering
International audienceLandslides are serious geologic disasters that threat human life and property in every country. In addition, landslides are one of the most important natural phenomena, which directly or indirectly affect countries' economy. Turkey is also the country that is under the threat of landslides. Landslides frequently occur in all of the Black Sea region as well as in many parts of Marmara, East Anatolia, and Mediterranean regions. Since these landslides resulted in destruction, they are ranked as the second important natural phenomenon that comes after earthquake in Turkey. In recent years several landslides happened after heavy rains and the resulting floods. This makes the landslide monitoring and mitigation techniques an important study subject for the related professional disciplines in Turkey. The investigations on surface deformations are conducted to define the boundaries of the landslide, size, level of activity and direction(s) of the movement, and to determine individual moving blocks of the main slide. This study focuses on the use of a kinematic deformation analysis based on Kalman Filtering at a landslide area near Istanbul. Kinematic deformation analysis has been applied in a landslide area, which is located to the north of Istanbul city. Positional data were collected using GPS technique. As part of the study, conventional static deformation analysis methodology has also been applied on the same data. The results and comparisons are discussed in this paper
Heating system evaluation of an ancient turkish bath : the bath of suleymaniye hospital
This research aims at evaluating the original heating system of the 16th century historic bath (hamam) section of Suleymaniye Hospital (Darüşşifa), a part of Süleymaniye Mosque Complex in Istanbul, in terms of its original heating system elements, their locations inside the building, suitability, and approximate dimensions and materials.Two types of heating system have been assessed within the context of the study. First, hypocaust underfloor heating provided by means of the circulation of hot smoke produced by the combustion of solid-fuel at the furnace of the bath and circulated under the floors of heated rooms of it has been evaluated. Second, wall heating provided by means of the circulation of this hot smoke inside the vertical chimneys called as tüteklik located inside the walls of the bath has been assessed. The research included the reconstitution of original heating system elements such as detection of original and possible locations of brick foots and smoke canals in hypocaust section, of vertical tüteklik chimneys inside the walls and their roof extensions, of furnace inside the building and included the distribution of heating system elements at the caldarium, halvet and tepidarium sections of the bath. Heated volumes of these spaces (V-m3), number of vertical tüteklik pipes (Tp-n) and ventilation holes (Vh-n) inside the walls of the rooms, thickness of the walls (Tw -m), volume of hot smoke circulated in hypocaust section (Vs –m3), and effective heated floor surface (Af-m2) were the main parameters of heating system elements determined in those spaces. Also, possible thermal performance analysis methods heating system elements of the bath of Suleymaniye Hospital have been investigated. The research developed in this study were considered useful for the evaluation heating system for the similar historical baths.Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016
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