Biomimetic sensor for in-vivo applications

The development of sensitive specific devices (e.g., molecular sensors) for the detection, diagnosis and monitoring of diseases, drug discovery, environmental detection of pollutants and/or biological agents has been an active area of research. A molecular sensor is a biomolecule or biomimetic molecule that performs two distinct functions in detecting target molecules. The sensor molecule recognizes a target molecule and specifically binds to it. This specific binding generates a signal in response to the event of target binding that can be then detected. The long term vision of this thesis research work is to develop a specific recognition ligand for detecting proteins in living cell. A molecular sensor for non-nucleic acid analytes (e.g., proteins, peptides, drugs, hormones) can be designed and demonstrated using molecular recognition and design principles analogous in some ways to the molecular switch principles used in Molecular Beacons invented by Dr. Kramer and Dr. Tyagi. Conventionally, people have looked at nucleic acids and antibodies used as nucleic acid recognizing nucleic acid and antigen recognizing antibody. Nucleic acids have protein binding capabilities i.e. they can act as aptamers having same design construct as molecular beacons. Aptamer nucleic acids act as antibodies which can detect antigens. This thesis work focuses on the development of some basic tools and concepts for the development of aptamer beacons, like immobilization of molecules on substrates and to determine the performance of specific binding assays

Localized states in sheared electroconvection

Electroconvection in a thin, sheared fluid film displays a rich sequence of bifurcations between different flow states as the driving voltage is increased. We present a numerical study of an annular film in which a radial potential difference acts on induced surface charges to drive convection. The film is also sheared by independently rotating the inner edge of the annulus. This simulation models laboratory experiments on electroconvection in sheared smectic liquid crystal films. The applied shear competes with the electrical forces, resulting in oscillatory and strongly subcritical bifurcations between localized vortex states close to onset. At higher forcing, the flow becomes chaotic via a Ruelle-Takens-Newhouse scenario. The simulation allows flow visualization not available in the physical experiments, and sheds light on previously observed transitions in the current-voltage characteristics of electroconvecting smectic films.Comment: To be published in EuroPhysics Letters, 6 pages, 6 figures: final versio

Ellipsometric measurements of the refractive indices of linear alkylbenzene and EJ-301 scintillators from 210 to 1000 nm

We report on ellipsometric measurements of the refractive indices of LAB-PPO, Nd-doped LAB-PPO and EJ-301 scintillators to the nearest +/-0.005, in the wavelength range 210-1000 nm.Comment: 7 pages, 4 figure

Weakly Nonlinear Analysis of Electroconvection in a Suspended Fluid Film

It has been experimentally observed that weakly conducting suspended films of smectic liquid crystals undergo electroconvection when subjected to a large enough potential difference. The resulting counter-rotating vortices form a very simple convection pattern and exhibit a variety of interesting nonlinear effects. The linear stability problem for this system has recently been solved. The convection mechanism, which involves charge separation at the free surfaces of the film, is applicable to any sufficiently two-dimensional fluid. In this paper, we derive an amplitude equation which describes the weakly nonlinear regime, by starting from the basic electrohydrodynamic equations. This regime has been the subject of several recent experimental studies. The lowest order amplitude equation we derive is of the Ginzburg-Landau form, and describes a forward bifurcation as is observed experimentally. The coefficients of the amplitude equation are calculated and compared with the values independently deduced from the linear stability calculation.Comment: 26 pages, 2 included eps figures, submitted to Phys Rev E. For more information, see http://mobydick.physics.utoronto.c

Investigating ship system performance degradation and failure criticality using FMECA and artificial neural networks

The goal of all maintenance methods is to eliminate failures or reduce their occurrence. Ex-tended downtime on key ships systems such as power generation plants can lead to undesirable consequences beyond economic and operational losses, especially considering naval vessels. One solution to overcome this challenge is through a system-specific analysis that identifies the most critical component and possible causes of delays be it technical or logistics. In this regard, this paper presents a methodology using FMECA approach that adopts the risk priority number differently to identify Mission Critical Components. This was supported with ANN classification using unsupervised learning to identify patterns in the data that signifies the onset of performance degradation and potential failures onboard an OPV. The study has identified some critical components and failure patterns that contribute to extended downtime based on survey and machinery maintenance reports. Recommendations were provided on preventing/mitigating the failures and how to prioritize existing ship systems maintenance

Compensated Row-Column Ultrasound Imaging System Using Fisher Tippett Multilayered Conditional Random Field Model

Ben Daya I, Chen AIH, Shafiee MJ, Wong A, Yeow JTW (2015) Compensated Row-Column Ultrasound Imaging System Using Fisher Tippett Multilayered Conditional Random Field Model. PLoS ONE 10(12): e0142817. doi:10.1371/journal.pone.01428173-D ultrasound imaging offers unique opportunities in the field of non destructive testing that cannot be easily found in A-mode and B-mode images. To acquire a 3-D ultrasound image without a mechanically moving transducer, a 2-D array can be used. The row column technique is preferred over a fully addressed 2-D array as it requires a significantly lower number of interconnections. Recent advances in 3-D row-column ultrasound imaging systems were largely focused on sensor design. However, these imaging systems face three intrinsic challenges that cannot be addressed by improving sensor design alone: speckle noise, sparsity of data in the imaged volume, and the spatially dependent point spread function of the imaging system. In this paper, we propose a compensated row-column ultrasound image reconstruction system using Fisher-Tippett multilayered conditional random field model. Tests carried out on both simulated and real row-column ultrasound images show the effectiveness of our proposed system as opposed to other published systems. Visual assessment of the results show our proposed system’s potential at preserving detail and reducing speckle. Quantitative analysis shows that our proposed system outperforms previously published systems when evaluated with metrics such as Peak Signal to Noise Ratio, Coefficient of Correlation, and Effective Number of Looks. These results show the potential of our proposed system as an effective tool for enhancing 3-D row-column imaging.This research was funded by the Natural Sciences and Engineering Research Council of Canada, the Canada Research Chairs Program, and the Ontario Ministry of Research and Innovation

Peningkatan Kemampuan Berkomunikasi dengan Peserta Didik melalui Supervisi Klinis Bagi Guru SD Negeri 5 Surabaya pada Semester I Tahun Ajaran 2016/2017

The ability of teachers to manage student interactions in learning activities relates to communication between students and other students, students with teachers and vice versa. The purpose of this study was to measure the improvement in the ability of Surabaya Elementary School 5 teachers to communicate with students after clinical supervision. This classroom action research was carried out by taking place at SD Negeri 5 Surabaya. The school's action research was conducted in the first semester of the 2016/2017 school year. The subject of this study was the teacher of SD Negeri 5 Surabaya, amounting to six teachers. The results of this study are the teacher's ability to communicate with students from cycle to cycle has increased, namely from prasiklus 33.86%, the first cycle of 66.08%, and the second cycle of 88.30%, so that the increase during the action is 54, 44%. Increases occur in all aspects. The increase in teachers' abilities was due to clinical supervision activities based on objective assessments that were delivered transparently to teachers, besides the implementation of supervision with a small number of teachers tended to facilitate communication between researchers, principals and teachers. The existence of such supervision increases the teacher's awareness of the importance of the ability to communicate with students, and raises the awareness of teachers that this ability is one aspect of teacher performance assessment

Real-time Processor-in-Loop investigation of a modified non-linear state observer using sliding modes for speed sensorless induction motor drive in electric vehicles

Tracking performance and stability play a major role in observer design for speed estimation purpose in motor drives used in vehicles. It is all the more prevalent at lower speed ranges. There was a need to have a tradeoff between these parameters ensuring the speed bandwidth remains as wide as possible. This work demonstrates an improved static and dynamic performance of a sliding mode state observer used for speed sensorless 3 phase induction motor drive employed in electric vehicles (EVs). The estimated torque is treated as a model disturbance and integrated into the state observer while the error is constrained in the sliding hyperplane. Two state observers with different disturbance handling mechanisms have been designed. Depending on, how they reject disturbances, based on their structure, their performance is studied and analyzed with respect to speed bandwidth, tracking and disturbance handling capability. The proposed observer with superior disturbance handling capabilities is able to provide a wider speed range, which is a main issue in EV. Here, a new dimension of model based design strategy is employed namely the Processor-in-Loop. The concept is validated in a real-time model based design test bench powered by RT-lab. The plant and the controller are built in a Simulink environment and made compatible with real-time blocksets and the system is executed in real-time targets OP4500/OP5600 (Opal-RT). Additionally, the Processor-in-Loop hardware verification is performed by using two adapters, which are used to loop-back analog and digital input and outputs. It is done to include a real-world signal routing between the plant and the controller thereby, ensuring a real-time interaction between the plant and the controller. Results validated portray better disturbance handling, steady state and a dynamic tracking profile, higher speed bandwidth and lesser torque pulsations compared to the conventional observer

Radioaktivitas Iodium-125 Pada Uji Produksi Menggunakan Target Xenon-124 Diperkaya

Telah dilakukan uji produksi 125I menggunakan target xenondiperkaya dengan pengayaan 124Xe sebesar 82,4%. Target diiradiasi neutron di kamar iradiasidi posisi S1 pada reaktor G.A. Siwabessy. Setelah iradiasi selama 24 jam, gas xenon teriradiasidiluruhkan di dalam botol peluruhan selama 7 hari. Radioisotop 125I yang terbentuk di dalambotol peluruhan dilarutkan menggunakan NaOH 0,005N sebanyak 3 kali. Dari uji produksi ke-1sampai dengan ke-8 diperoleh radioaktivitas total 125I sebesar 9541, 9801, 11239, 9458, 3293,3735, 4693 dan 2744 mCi. Penurunan radioaktivitas total 125I disebabkan oleh penurunanjumlah gas target. Radioaktivitas 125I hasil pelarutan pertama bergantung pada volume larutanNaOH yang digunakan. Persentase rerata radioaktivitas 125I pada pelarutan pertama sebesar65,1%, 71,5% dan 82,6% dari radioaktivitas total untuk pelarutan menggunakan larutan NaOHdengan volume 3, 4 dan 5 mL. Konsentrasi radioaktivitas maksimum yang berhasil diproduksisebesar 3410 mCi/mL dari hasil pelarutan pertama dari uji produksi pertama