System identification and model-based flight control system design for an agile maneuvring quadrotor platform

In this paper, we provide a system identification, model stitching and model-based flight control system design methodology for an agile maneuvering quadrotor micro aerial vehicle (MAV) technology demonstrator platform. The proposed MAV is designed to perform agile maneuvers in hover/low-speed and fast forward flight conditions in which significant changes in system dynamics are observed. As such, these significant changes result in considerable loss of performance and precision using classical hover or forward flight model based controller designs. To capture the changing dynamics, we consider an approach which is adapted from the full-scale manned aircraft and rotorcraft domain. Specifically, linear mathematical models of the MAV in hover and forward flight are obtained by using the frequency-domain system identification method and they are validated in time-domain. These point models are stitched with the trim data and quasi-nonlinear mathematical model is generated for simulation purposes. Identified linear models are used in a multi objective optimization based flight control system design approach in which several handling quality specifications are used to optimize the controller parameters. Lateral reposition and longitudinal depart/abort mission task elements from ADS-33E-PRF are scaled-down by using kinematic scaling to evaluate the proposed flight control systems. Position hold, trajectory tracking and aggressiveness analysis are performed, Monte-Carlo simulations and actual flight test results are compared. The results show that the proposed methodology provides high precision and predictable maneuvering control capability over an extensive speed envelope in comparison to classical control techniques. Our current work focuses on i) extension of the flight envelope of the mathematical model and ii) improvement of agile maneuvering capability of the MAV

The comparison of high and standard definition computed tomography techniques regarding coronary artery imaging

Objective: The aim was to compare coronary high-definition CT (HDCT) with standard-definition CT (SDCT) angiography as to radiation dose, image quality and accuracy. Material and Methods: 28 patients with history of coronary artery disease scanned by HDCT (Discovery CT750 HD) and SDCT (Somatom Definition AS). The scan modes were both axial prospective ECG-triggered. The vessel diameters and vessel attenuation values of totally 280 measurements from 140 coronary arteries were analyzed by two experienced radiologists. All data was analyzed by intraclass correlation test. Image quality graded by motion and stair step artifacts (grade 1, poor, to grade 4, excellent), accuracy of vessel inner and outer diameters were compared between the two CT units using the independent samples t-test and Mann-Whitney U test. Results: The intraclass correlation coefficient (ICC) of measured vessel attenuation values in SDCT between the two radiologists was exceedingly good. The ICC was higher in HDCT. The radiation dose of HDCT was higher than that of SDCT. The mean tube current was 180 (mA) in HDCT and 147(mA) in SDCT with the same tube voltage (kVp). There was no significant difference between image quality. Conclusion: HDCT has a higher radiation dose but has much more atenuation and the spatial resolution which improve measurement accuracy for imaging coronary arteries

Coronary artery bypass surgery without blood transfusion; is it possible?

Background: Coronary artery bypass surgery is the most commonly performed cardiac operation and approximately 40-70% of patients require a blood transfusion despite improvements in cardiac surgical techniques. Some preventive perfusion methods to avoid transfusions are described, such as acute normovolemic hemodilution, retrograde autologous priming, and usage of integrated arterial filter oxygenator. Aims: We combined these three techniques (triple combination technique) to evaluate whether it is possible to avoid blood transfusions in adult patients undergoing coronary artery bypass surgery. Materials and Methods: A total of 300 consecutive patients were included in this randomized controlled trial. 150 patients (Group 1) were operated with triple combination technique, The other 150 patients (Group 2) were operated with standard cardiopulmonary bypass technique. The two groups were compared in terms of peroperative and postoperative blood product use. Results: Ninety-two percent (92%) of the patients (Group 1) undergoing coronary artery bypass surgery did not require any blood transfusion. Only 8% of the patients required erythrocyte suspension or fresh frozen plasma transfusion. In Group 2, 58% of patients required blood transfusions. The difference between two groups was statistically significant (p < 0,05). Conclusion: Triple combination technique is safe and cost-effective in coronary artery bypass surgery. We think that most of the patients could be operated without blood transfusion with this technique

Amperometric glucose sensor based on the glucose oxidase enzyme immobilized on graphite rod electrode modified with Fe3O4-CS-Au magnetic nanoparticles

Cetin, Demet/0000-0003-1186-4229WOS: 000450111000030In this report, an amperometric detection method for blood glucose level was developed benefiting from glucose oxidase (GO) enzyme immobilization on nanoparticle modified graphite rod (GR) electrode. Fe3O4-CS-Au magnetic nanoparticles were synthesized, characterized by TEM, UV-Vis, magnetometry, FTIR, and zeta potential measurements and used for the modification of GR electrode. This modified electrode was used for the detection of glucose level amperometrically at 0.6 V. The obtained calibration graph was linear in the range of 5-30mM glucose concentration with a coefficient of determination (R-2) 0.9971. The limit of detection (LOD) and limit of quantification (LOQ) values were calculated as 0.55 and 1.83mM, respectively. The modified GR electrode showed excellent selectivity in the presence of dopamine, ascorbic acid, and uric acid. The applicability of the developed method was examined in real blood samples by comparing the results obtained from commercial glucose sensor. This novel glucose detection method exhibited fast amperometric response, long storage time, and good selectivity

Open and Interoperable Maritime Surveillance Framework Set to Improve Sea-Borders Control

This study presents an open and interoperable maritime surveillance framework with multimodal sensor networks and an automated decision-making. The intention is to improve sea-border control, plugging the gaps in the maritime security with interoperability solutions and have wide-area situational awareness, thus particular reducing the number of illegal immigrants crossing sea borders in small boats, with a cost-effective approach. In this paper initial results are presented. This research is a part of a European project supported by ITEA2, Eureka Cluster Programme (RECONSURVE Project, no: ITEA2 09036)

A Practical MRI Technique for Detecting Abdominal Aorta Aneurysm and Peripheral Arterial Disease

WOS: 000376566800003Aim: Peripheral Arterial Disease(PAD) and abdominal aorta aneurysm(AAA) are frequent problems in geriatric population. In DSA, CTA or MRA techniques contrast agents has to be used for diagnosis that can be nephrotoxic for elderly patients. Magnetic resonans imaging (MRI) is the most powerful, non-ionising radiological diagnostic tool that has the highest soft tissue contrast resolution. The aim of our study was to investigate the effectivity of MRI by the means of detecting the AAA and PAD in comparison with DSA. Material and Method: After getting ethical commitee approvel and informed consent, we have performed Balanced turbo field echo(B-TFE) MRI technique without contrast agent in 1.5 Tesla MRI device before DSA examination. The luminal diameters of renal arteries, infrarenal abdominal aorta, iliac and femoral arteries was measured by using Philips DICOM Viewer R2.2 application. The intraclass corelation coefficient and reliability used to check if the techniques could be used for each other and the t-test was used to measure the differences between them. Results: There has been a high relationship between B-TFE and DSA in detecting the pathologies of larger arteries like aorta. In the case of small arterial pathologies, there is relatively lower relationship between BTFE and DSA. Discussion: For the diagnosis of AAA and PAD, DSA is the gold standart technique but it is invasive and patients have radiation exposure. In the follow up of geriatric patients with larger arterial pathologies B-TFE can be used instead of contrast enhanced MRA and invasive DSA

Comparing 1470-and 980-nm diode lasers for endovenous ablation treatments

WOS: 000356531400022PubMed: 25990260The purpose of this study was to compare the effectiveness of 1470- and 980-nm lasers with regard to power output, complications, recanalization rates, and treatment response. We prospectively evaluated the effectiveness of endovenous laser ablation (EVLA) in a total of 152 great and small saphenous veins from 96 patients. Lasers were randomly used based on the availability of the units. Patients were clinically evaluated for Clinical Etiologic Anatomic Pathophysiologic (CEAP) stage and examined with Doppler ultrasound. Treatment response was determined anatomically by occlusion of the vein and clinically by the change in the venous clinical severity score (VCSS). Seventy-eight of the saphenous veins underwent EVLA with a 980-nm laser and 74 underwent EVLA with a 1470-nm laser. Treatment response was (68) 87.2 % in the 980-nm group and (74) 100 % in the 1470-nm group (p = 0.004). The median VCSS decreased from 4 to 2 in the 980-nm group (p < 0.001) and from 8 to 2 (p < 0.001) in the 1470-nm group. At 1-year follow-up, seven veins treated with 980 nm and two veins treated with 1470 nm were recanalized (p = 0.16); the average linear endovenous energy density (LEED) was 83.9 (r, 55-100) J/cm and 58.5 (r, 45-115) J/cm, respectively (p < 0.001). Postoperative minor complications occurred in 23 (29.4 %) limbs in the 980-nm group and in 19 (25.6 %) limbs of the 1470-nm group (p = 0.73). EVLA with the 1470-nm laser have less energy deposition for occlusion and better treatment response

PULMONARY EMBOLISM: CARDIOVASCULAR AND PARENCHYMAL CHANGES

WOS: 000435654000009Aim: To investigate the effects and the severity of pulmonary embolism on the cardiovascular system and lung parenchyma. Material and Method: Pulmonary artery (PA) obstruction index ratios were calculated, and cardiovascular and pleuroparenchymal changes were retrospectively assessed in 180 patients with a prediagnosis of PE using computerized tomography pulmonary angiography (CTPA). Results: Main PA, right PA, and mean superior vena cava (VCS) diameters, right (RV) and left ventricle (LV) short diameters, and RV/LV ratios in patients with PE were increased (p<0.001, p=0.004, p=0.007, p=0.01, p=0.001, respectively) and correlated with the obstruction index ratio (OIR). Also, the convexity of the interventricular septum, VCI, and vena azygos reflux frequency were increased with PE (p<0.001, p=0.001, p=0.001) and with massive PE (p<0.001, p=0.003, p<0.001). It was determined that the frequency of the presence of wedge-shaped opacities and vein mark findings was increased in patients with PE (p<0.001, p<0.001); however, it was found less frequently in patients with massive PE when compared to the submassive patients (p=0.002, p=0.014). The presence of atelectasis was not different between patients with and without PE; consolidation, ground glass appearance, oligemia frequency, and the average scores were increased in the patients with PE (p=0.02, p<0.001, p=0.001), and there was a positive correlation between the oligemia score and OIR (r=0.202, p=0.027). Pleural effusion was infrequent with PE. Discussion: CTPA is a rapid and reliable method for the determination of the severity of PE, affected vascular structures and lung regions, and for the assessment of right heart function

High-yield aqueous synthesis of multi-branched iron oxide core-gold shell nanoparticles: SERS substrate for immobilization and magnetic separation of bacteria

Bayram, Cem/0000-0001-8717-4668; Cetin, Demet/0000-0003-1186-4229; SULUDERE, ZEKIYE/0000-0002-1207-5814; Tamer, Ugur/0000-0001-9989-6123; Greneche, Jean-Marc/0000-0001-7309-8633; Lagarde, Fabienne/0000-0002-4015-4376WOS: 000341752200001The high product yield of multi-branched core-shell Fe3-x O-4@Au magnetic nanoparticles was synthesized used as magnetic separation platform and surface-enhanced Raman scattering (SERS) substrates. The multi-branched magnetic nanoparticles were prepared by a seed-mediated growth approach using magnetic gold nanospheres as the seeds and subsequent reduction of metal salt with ascorbic acid in the presence of a stabilizing agent chitosan biopolymer and silver ions. The anisotropic growth of nanoparticles was observed in the presence of chitosan polymer matrix resulting in multi-branched nanoparticles with a diameter over 100 nm, and silver ions also play a crucial role on the growth of multi-branched nanoparticles. We propose the mechanism of the formation of multi-branched nanoparticles while the properties of nanoparticles embedded in chitosan matrix are discussed. The surface morphology of nanoparticles was characterized with transmission electron microscopy, scanning electron microscopy, ultraviolet visible spectroscopy (UV-Vis), X-ray diffraction, and fourier transform infrared spectroscopy and Fe-57 Mossbauer spectrometry. Additionally, the magnetic properties of the nanoparticles were also examined. We also demonstrated that the synthesized Fe3-x O-4@Au multi-branched nanoparticle is capable of targeted separation of pathogens from matrix and sensing as SERS substrates.Scientific and Technological Research Council (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [108T794, 111T983]; Gazi BAPGazi University [05/2004-03, 05/2011-69]This work was supported by the Scientific and Technological Research Council (TUBITAK) grant numbers 108T794 and 111T983. We also acknowledge support from Gazi BAP, project number 05/2004-03 and 05/2011-69. We would like to thank Gokhan Demirel and Mehmet Yilmaz for 3D simulation. We also thank to Dr Saime Sebnem Cetin and Prof.Dr. Suleyman Ozcelik for XRD measurements