Electro Standards Laboratories (United States)

The goal of this paper is to present a method to design a digital controller for a motor driven aircraft subscale arrestment system of the type used on aircraft carriers. Sensors in the system are limited and there are no sensors on the aircraft being controlled. The uncertainty in the aircraft's orientation and position during arrestment along with the nonlinear dynamics and limited sensors result in control challenges. The focus of this paper is on the arrest phase controller that decelerates the plane along a reference trajectory to bring it to a final stop without steering it astray. It is based on an adaptive linear quadratic Gaussian/loop transfer recovery (LQG/LTR) control algorithm. The controller development uses a multi-input multi-output (MIMO) design technique. This is important for high performance since the system behaviors are coupled and simplifying techniques that ignore this coupling do not have the flexibility to achieve optimal performance. The algorithm developed here generates a good tracking performance for the aircraft position and velocity and successfully arrests the aircraft within bounds. The simulation and experimental results using a subscale arrestment system have shown the effectiveness of the proposed algorithm.

While the bone marrow (BM) microenvironment is significantly remodelled in acute myeloid leukaemia (AML), molecular insight into AML-specific alterations in the microenvironment has been historically limited by the analysis of liquid marrow aspirates rather than core biopsies that contain solid-phase BM stroma. We assessed the effect of anthracycline- and cytarabine-based induction chemotherapy on both haematopoietic and non-haematopoietic cells directly in core BM biopsies using RNA-seq and histological analysis. We compared matched human core BM biopsies at diagnosis and 2 weeks after cytarabine- and anthracycline-based induction therapy in responders (<5% blasts present after treatment) and non-responders (≥5% blasts present after treatment). Our data indicated enrichment in vimentin (VIM), platelet-derived growth factor receptor beta (PDGFRB) and Snail family transcriptional repressor 2 (SNAI2) transcripts in responders, consistent with the reactivation of the mesenchymal population in the BM stroma. Enrichment of osteoblast maturation-related transcripts of biglycan (BGN), osteopontin (SPP1) and osteonectin (SPARC) was observed in non-responders. To the best of our knowledge, this is the first report demonstrating distinct osteogenic and mesenchymal transcriptome profiles specific to AML response to induction chemotherapy assessed directly in core BM biopsies. Detailing treatment response-specific alterations in the BM stroma may inform optimised therapeutic strategies for AML.

An overview of a hybrid wave/solar energy harvesting buoy currently being developed by Electro Standards Laboratories (ESL) is presented here. Through previous work with the University of Rhode Island, a resonant-drive buoy system was designed, constructed and tested at sea. ESL has continued to improve upon the original resonant buoy design by incorporating a larger, more powerful linear electric generator with adaptive load control as well as the addition of flexible solar panels to capture a second source of renewable energy using a maximum power point tracking algorithm. Laboratory testing of the modified elements of the hybrid energy harvesting buoy have shown promising results. At sea field testing of the buoy is planned during the second half of 2013.

A novel estimation methodology is developed which can be used to evaluate the potential benefits of implementing a hybrid battery-supercapacitor system to improve battery life. This approach allows for a quick comparison of battery-only versus a hybrid battery-capacitor system in terms of maximizing battery efficiency without the need for complicated and detailed computer simulations. Experimental results are presented to validate this technique.

Commercial manufacturing methods have been used to fabricate a planar, self-heated, tape-cast, mixed-potential NOx sensor for application in vehicle on-board emission control systems. The device consists of dense La0.8Sr0.2CrO3 (LSCrO) and Pt electrodes and a porous YSZ electrolyte on one side of a dense ceramic substrate and a Pt-heater with independent leads on the backside of the substrate. These planar mixed-potential sensors are capable of selectively detecting ppm levels of NOx when operated at a positive bias. Additionally, the device has yielded stable performance under months of testing as a result of the stable morphology of the electrode/electrolyte/gas phase interface.

not Available.

ABSTRACT Over the last several years, the electronics assembly industry has witnessed a seismic shift toward component miniaturization. Consumer demands for more functionality in smaller packages have motivated OEMs and Contract Manufacturers to engage in new and innovative technologies. As technological advances usher in a more compact design, a decrease in available board space and more densely populated PCB's have become increasingly common. In response to these demands, the industry has witnessed a proliferation of Quad Flat No Leads (QFN) packages. The goal of this study is to identify the advantages and challenges that the QFN package brings to the electronics assembly process. This paper will also discuss the results of data evidencing the fundamental steps required to successfully implement QFN technology into an assembly.

Methodology and results are presented for the numerical simulations and experimental measurements of an electrically based absolute position sensing system with a linear synchronous machine for a General Atomics' developed Urban MagLev train. The results demonstrate the feasibility of using a novel method to provide absolute position sensing of a shuttle along a track and the system provides robust performance without sensitivity to shuttle vibrations, vertical displacement and common mode electrical noise.

Methodology and results are presented for the numerical simulations and experimental measurements on ocean energy harvesting systems that utilize anchored linear generators, driven by heaving surface buoys that convert ambient ocean wave energy into useful electrical power. The results demonstrate the feasibility of using ocean wave energy harvesting buoys and simple linear generators to provide sufficient electrical power for ocean sensor applications (1-10 W range). Experimental results for a small scale linear generator, directly driven in a test bed with realistic ocean wave spectra, demonstrate power in the 5-10 W range. Simulations for buoy/generator systems using imperfectly wave-compliant surface buoys and two different anchoring approaches show that the wave compliance of the buoy and the method of anchoring have a major effect on performance. These simulations for practical system designs show performance in the 1-4 W range.

Optimal operation of switched reluctance motor drives is inherently dependent to proper excitation of motor phases with respect to their inductance profile. Based on this fact, utilization of position transducers in the drive is unavoidable. These transducers increase the cost and complexity of the drive. In this paper, a new method for elimination of position sensors in SRM drives is suggested. The proposed method is a marriage of chopping waveform analysis and inductance modeling based on Fourier series. A novel method for online estimation of back emf based on chopping current waveform is introduced. Besides, incremental inductance profile is modeled and automatically calibrated for robust operation. By evaluation of estimated back emf and phase inductance model, position information will be obtained. This approach does not suffer from unpredicted variation of magnetic characteristics since it benefits model auto tuning. The proposed method has implemented successfully on experimental SRM drive based on TMS320F2470 digital signal processor.