Connector Port Research Articles

Traceable characterisation of fibre-coupled single-photon detectors

Abstract The detection of single photons plays an essential role in advancing single-photon science and technologies. Yet, within the visible/near-infrared spectral region, accurate fibre-based optical power measurements at the few-photon level are not yet well-established. In this study, we report on a fibre-based setup, enabling traceable optical power measurements at the few-photon level in this spectral region. The setup was used to calibrate the detection efficiency (DE) of four single-photon avalanche diode (SPAD) detectors. The relative standard uncertainties on the mean DE values obtained from repeat fibre-to-detector couplings ranged from 0.67% to 0.81% (k = 2). However, the relative standard deviation of DE values, which ranged from 1.38% to 3.20% (k = 2), poses a challenge for the metrology of these devices and applications that require high accuracy and repeatability. We investigated the source of these variations by spatially mapping the response of a detector’s fibre connector port, using a focused free-space beam, allowing us to estimate the detector’s spatial non-uniformity. In addition, we realise a novel calibration approach for fibre-coupled SPADs in a free-space configuration, enabling a direct comparison between the fibre-based setup and the National Physical Laboratory’s established free-space facility using a single SPAD. Finally, we investigated alternative coupling methods, testing the repeatability of different fibre-to-fibre connectors in addition to direct fibre-to-detector couplings: SPADs from three manufacturers were tested, with both single-mode and multi-mode fibre.

Food and Drug Administration Malfunction Recalls of Left Ventricular Assist Devices.

Left ventricular assist devices (LVADs) are being increasingly implanted given the increasing prevalence of patients with advanced heart failure stages. However, they are not exempt from device malfunctions. A PubMed search for the key words (left ventricular assist device malfunction) (ventricular assist system malfunction) was performed. We identified 28 publications in the US Food and Drug Administration (FDA) website database that addressed LVAD malfunction. Twenty-nine FDA recalls were identified regarding LVAD malfunctions: 17 regarding HeartWare ventricular assist device, six for HeartMate II, three for HeartMate 3, and three for total artificial heart. Mechanisms involved in LVAD malfunction include battery malfunction, loose driveline connector, malfunction of the system controller, loose power supply connector ports, malfunction of the driveline splice kit, problems with the percutaneous lead connection, disconnection of the bend relief and outflow graft and outflow graft occlusion among others. Multiple mechanisms could be linked to LVAD malfunction. However, multiple device modifications have been developed over the past decade to avoid recurrent malfunctions. Constant improvements and research in biotechnology are needed to prevent these complications. It remains to be seen if newer generation devices will lead to improved patient outcomes over the long term.

Algorithm to Image Identification and Artix-7 FPGA Implementation for Adequate Edge Detection.

For any image identification based applications, edge detection is the primary step. The intention of the edge detection in image processing is to minimize the information that is not required in the analysis of identification of an image. In the process of reduction of insignificant data in the image, it may lead to some loss in information which in turn raise some problems like missing of boundaries with low contrast, false edge detection and some other noise affected problems. In order to reduce the effects due to noise, a modified version of popular edge detection algorithm “Canny edge detection algorithm” is proposed. Artix 7 FPGA board set up is used to implement, by using Xilinx platform the image that is obtained as output is displayed on monitor which is connected with FPGA board using connector port DVI. MATLAB Simulink is used for algorithm simulation and then it is executed on FPGA board using Xilinx platform. The results provide good motivation to use in different edge detection applications.

A Grid-Connected Smart Extendable Structure for Hybrid Integration of Distributed Generations

In this paper, a novel grid-connected smart and plug-and-play type extendable structure named unified multiport power electronic converter (UMPEC) for hybrid integration of distributed generation (DG) systems is presented. The proposed structure contains two types of connector ports. The first one is a set of AC connectors, which can be easily used to connect different types and numbers of AC-based DGs along with grid and loads. The second one is a set of DC connectors, which can interface DC-based DGs and storage units. Compared with the conventional and recently invented multi-stage power electronic topologies, the proposed structure enjoys less number of power electronic components, compactness, and plug-and-play capability of integrating AC and DC-based DGs. Considering shared components between different ports and their imposed boundaries on the operation of the UMPEC, a modified sequential space vector modulation is addressed, which makes it possible to control different ports independently, without compromising with maximum power harnessing from individual sources, which is another salient feature of this work. The proposed structure operation and performance is verified using a three DC and two AC connectors version, where wind and photovoltaic systems are independently interfaced to the grid.

NTCT-12UPDATED SAFETY ANALYSIS OF BEVACIZUMAB PLUS ALTERNATING ELECTRIC FIELDS THERAPY IN PATIENTS WITH RECURRENT MALIGNANT GLIOMAS

BACKGROUND: Bevacizumab and NovoTTF Therapy are treatments approved by the FDA for recurrent glioblastoma. We updated our single-institution experience in using this combination for patients with recurrent malignant gliomas. METHODS: We identified from January 2012 to May 2015 the side effects experienced by patients while on bevacizumab and NovoTTF Therapy, together with their dexamethasone usage. Overall survival (OS) was also tabulated. RESULTS: Out of 53 patients in the cohort, there were 25 men and 13 women who received both treatments. Their median age was 54 (range 29-76). All had Karnofsky Performance Score of 60 or above. The median on-treatment time was 3.3 (range 0.2-31.7) months. Adverse events include minor scalp rash (9), electric shock sensations (5), liquefied hydrogels from high ambient temperature (5), array removal during sleep (3), vivid dreams (2), scalp ulcers (2), confusion with connector ports (2), scalp pruritis (1) and meningitis from contemporaneous craniotomy (1). Seven (18%) required treatment interruption, but only one grade 3 scalp rash (3%) and one grade 4 meningitis (3%) resulted in prolonged treatment interruption or cessation. No hemorrhagic complication or thromboembolism was seen. The concurrent use of bevacizumab enabled a majority to lower dexamethasone usage below 4 mg/day and the median on-treatment duration was 4.2 months in patients who used 4 mg/day, respectively (P = 0.05). CONCLUSIONS: No additive or synergistic side effects were observed and the addition of bevacizumab helped to lower dexamethasone requirement among patients treated with NovoTTF Therapy. Future prospective evaluation will be needed to assess both side effects and efficacy of this treatment combination.

Design of a microfluidic device for comprehensive spatial two-dimensional liquid chromatography.

This study discusses the design aspects for the construction of a microfluidic device for comprehensive spatial two-dimensional liquid chromatography. In spatial two-dimensional liquid chromatography each peak is characterized by its coordinates in the plane. After completing the first-dimension separation all fractions are analyzed in parallel second-dimension separations. Hence, spatial two-dimensional liquid chromatography potentially provides much higher peak-production rates than a coupled column multi-dimensional liquid chromatography approach in which the second-dimension analyses are performed sequentially. A chip for spatial two-dimensional liquid chromatography has been manufactured from cyclic olefin copolymer and features a first-dimension separation channel and 21 parallel second-dimension separation channels oriented perpendicularly to the former. Compartmentalization of first- and second-dimension developments by physical barriers allowed for a preferential flow path with a minimal dispersion into the second-dimension separation channels. To generate a homogenous flow across all the parallel second-dimension channels, a radially interconnected flow distributor containing two zones of diamond-shaped pillars was integrated on-chip. A methacrylate ester based monolithic stationary phase with optimized macroporous structure was created in situ in the confines of the microfluidic chip. In addition, the use of a photomask was explored to localize monolith formation in the parallel second-dimension channels. Finally, to connect the spatial chip to the liquid chromatography instrument, connector ports were integrated allowing the use of Viper fittings. As an alternative, a chip holder with adjustable clasp locks was designed that allows the clamping force to be adjusted.

Distributed Optical Fiber in High RCC Arch Dam Project

As the highest RCC(Roller Compacted Concrete) arch dam under construction around the world, Wanjiakouzi adopted advanced distributed temperature system (DTS). This paper summarizes the network design, technical requirements as well as the protection precautions of fiber connector and monitoring port of temperature measurement system of optical fiber in high RCC arch dam in Wanjiakouzi. It can be indicated that the accuracy and reliability of DTS by comparing fiber optic temperature values with the conventional thermometer measured values. The analysis and monitoring results show that the temperature measurement system of optical fiber can truly monitor and reflect the change process of heat of hydration of RCC, gradation and the cooling water pipe to temperature.

Novel method for intensity correction using a simple maskless lithography device

A simple, cost effective digital micromirror device (DMD) based maskless exposure device with a novel illumination correction is presented. The small scale laboratory setup with the presented construction details can be used with virtually any microscope with a suitable connector port. We demonstrate a technique for equilibration of intensity inhomogeneity which can be measured on the projection plane. The proposed technique enables pixel wise exposure dose manipulation. Consequently, unlike other systems, we are able to use the entire projected area for exposure with a feature size independent finite exposure time for a selected area. The long working distance makes it possible to expose surfaces located in a well or structures with variable heights which otherwise would not be exposable by conventional contact exposure. This simple setup is particularly helpful in fast, inexpensive prototyping of low resolution microstructures and sensor layouts. Features on silicon, glass and metal have been successfully patterned.

Multi-channel pre-beamformed data acquisition system for research on advanced ultrasound imaging methods

The lack of open access to the pre-beamformed data of an ultrasound scanner has limited the research of novel imaging methods to a few privileged laboratories. To address this need, we have developed a pre-beamformed data acquisition (DAQ) system that can collect data over 128 array elements in parallel from the Ultrasonix series of research-purpose ultrasound scanners. Our DAQ system comprises three system-level blocks: 1) a connector board that interfaces with the array probe and the scanner through a probe connector port; 2) a main board that triggers DAQ and controls data transfer to a computer; and 3) four receiver boards that are each responsible for acquiring 32 channels of digitized raw data and storing them to the on-board memory. This system can acquire pre-beamformed data with 12-bit resolution when using a 40-MHz sampling rate. It houses a 16 GB RAM buffer that is sufficient to store 128 channels of pre-beamformed data for 8000 to 25 000 transmit firings, depending on imaging depth; corresponding to nearly a 2-s period in typical imaging setups. Following the acquisition, the data can be transferred through a USB 2.0 link to a computer for offline processing and analysis. To evaluate the feasibility of using the DAQ system for advanced imaging research, two proof-of-concept investigations have been conducted on beamforming and plane-wave B-flow imaging. Results show that adaptive beamforming algorithms such as the minimum variance approach can generate sharper images of a wire cross-section whose diameter is equal to the imaging wavelength (150 μm in our example). Also, planewave B-flow imaging can provide more consistent visualization of blood speckle movement given the higher temporal resolution of this imaging approach (2500 fps in our example).

A Membrane Cell for On-line Hydrogen/Deuterium Exchange to Study Protein Folding and Protein-Protein Interactions by Mass Spectrometry

A membrane cell for hydrogen and deuterium exchange on-line with mass spectrometry has been developed to monitor protein-protein interactions and protein conformations. It consists of two channels separated by a semipermeable membrane, where one channel carries the protein sample and the other deuterium oxide. The membrane allows transfer of deuterium oxide into the sample flow. The labeling time is controlled via the flow rate in the sample channel. This cell was validated against three models commonly used in hydrogen-deuterium exchange mass spectrometry: monitoring of folded and unfolded states in a protein, mapping the protein secondary structure at the peptide level, and detection of protein and antibody interactions. The system avoids the conventionally used sample dilution and handling, allowing for potential automation.

Dry Subsea Production Systems: Garoupa-a Case History

Introduction Subsea one-atmosphere chambers for early petroleum production schemes or for wells beyond the reach of platforms have been in commercial use for several years. Such chambers are onstream in the Gulf of Mexico and offshore Brazil for Shell, Union Oil, Tenneco and Petrobras. This paper begins with a brief description of equipment experience with dry production system hardware supplied by Can Ocean Resources Ltd. (formerly Lockheed Petroleum Services) and installed in the Gulf of Mexico, and an outline of the impact on one-atmosphere technology for deepwater applications. The major and concluding part of the paper describes the Garoupa production system installed offshore Brazil for Petrobras. This system is one of the most ambitious undertakings of its kind and, therefore, a noteworthy case history of dry, subsea production technology. An over-all system description, key hardware descriptions and installation of the major subsea components are included in the paper. System commissioning and start-up progress to the end of February 1980 is described and some of the problems encountered, their solution and their impact on the project schedule are discussed. Introduction Every dry, one-atmosphere chamber has two basic functions in common: to isolate the equipment it contains from the subsea environment, and to allow trained oilfield technicians access to that equipment for installation and subsequent servicing. The first chamber (Fig. 1) was installed to produce oil from a subsea well in 114 m (375 ft) in the Gulf of Mexico by Shell Oil Company. At that time (mid 1972), it was the deepest producing subsea completion in the world. This single satellite well is still in production. A flow line carries well production to a nearby platform in shallower water. The one-atmosphere wellhead, called a wellhead cellar (WHC), encloses the Xmas tree, the hydraulic control package, and includes a flow-line connection port: A typical connector port is shown in Figure 2 during land tests for fitting the flow-line termination (bullnose) into it. A one-atmosphere servicing system (Fig. 3), consisting of a tethered diving bell, known as a service capsule, and surface support vessel (SSV), provided for personnel transfer to subsea chambers. The service capsule is rated for 365-m (1,200-ft) water depths and enabled work to be performed subsea on a 12-hour shift to set the Xmas tree, connect the flow line, and conduct final equipment preparation and checkout before well production start-up. Shell Manifold Center System In August 1975, Shell Oil Company successfully installed, in the Gulf of Mexico, an encapsulated subsea manifold center (MC) designed and developed by CanOcean. Figure 4, illustrates the part played by the MC in the subsea scheme. The 1-tonne MC (Fig. 5), with a chamber size 9.2 m (30 ft) long and 3.7 m (12 ft) in diameter, was designed to handle production from three wells in the Eugene Island Block 330 field. After installation in 74 m (240 ft) of water, and connections by flow line to satellite subsea wells and the adjacent platform, production commenced in August 1976.