Paper Describes Design Considerations Research Articles

Integrating local solar energy and water recovery: Operating experiences of a systemic approach

Abstract The key message is the importance of a systemic approach to handling water and energy together, both in design and in operation. The paper demonstrates how renewable energy, solar photovoltaic (PV) and solar thermal, in combination with a small nutrient removal plant, provides a reliable solution for small-scale decentralized water recovery operations. The system is automated and can operate outside the power grid and is designed to be a fully circular system in terms of both energy and water. The system has been installed on an island in the archipelago outside Stockholm, Sweden, to replace an old-fashioned septic tank. The effluent must satisfy rather strict effluent quality criteria for the Baltic Sea. The paper describes design considerations, instrumentation aspects, automation features, and operation experiences.

DEVELOPMENT OF A RF BIOSENSOR DESIGN TO DETECT CHANGES IN SCATTERING PARAMETERS OF AQUEOUS MATERIALS DURING RADIO FREQUENCY WAVE EXPOSURE

The advancing field of biosensor design continues pushing for smaller, inexpensive, yet accurate sensor designs. A subset of biosensors operating in the radio frequency (RF) range of electromagnetic (EM) waves, called RF biosensors, offer appeal as a non-destructive, non-invasive form of sensing. A novel RF biosensor is proposed which detects changes in scattering parameter measurements of a microliter, aqueous material under test (MUT) held within a well adjacent to a microstrip transmission line. This sensing design measures scattering parameter data and changes in these measurements offer insight into the effects of RF wave exposure on dielectric materials within the well. The following paper describes design considerations and the sensing technique of the proposed RF biosensor. Simulations were run in incremental steps to first, establish the simulation design of a 50-ohm microstrip transmission line using two software packages ADS and Ansys HFSS. Next, experimental measurements were collected by milling the RF biosensor, first using air and then distilled water as the MUT, and finally comparing to simulations to establish validity of the novel sensing device. Next, experimental S-parameter measurements were obtained and compared between the two test cases to determine if a difference could be detected. Both simulated and experimentally obtained measurements suggest the designed RF biosensor can detect changes in the MUT loaded inside its etched well and therefore can be used as a sensing device.

Design considerations for a remote randomized multi-site clinical trial evaluating an e-health self-management program for chronic pain patients receiving opioid therapy

Based on the adverse consequences and inadequate evidence of effectiveness for long-term opioid therapy (LOT), the CDC developed recommendations to decrease the use of LOT and morphine equivalent dose (MED) for patients receiving LOT. However, the majority of these patients report that opioid medication is significantly beneficial for pain management and are hesitant to reduce/decrease its use. Compounding the problem is poor access to non-pharmacologic therapies for many patients due to insurance reimbursement structures and limited pain-service availability. EMPOWER is an intent-to-treat, two-arm, open-label, randomized controlled trial evaluating a web-based self-management chronic pain program (E-Health) that has been found to reduce self-reported MED, while also decreasing pain, in two randomized controlled trials. Approximately 400 chronic pain patients receiving LOT at a daily average prescribed MED ≥ 20 mg at one of two U.S. healthcare systems, located in North Carolina and Ohio, will be randomized in a 1:1 ratio to treatment as usual (TAU) or TAU plus E-Health (E-Health+). TAU consists of LOT from a prescribing clinician. E-Health+ participants are provided with a 4-month E-Health subscription (active treatment phase). All participants will complete web-based self-report measures at baseline, the end of the active treatment phase, and 6-months post-active treatment. Opioid prescription information will be collected from the participants' electronic health record (EHR) from baseline through 6 months post-active treatment. This paper describes design considerations for this unique trial which is conducted completely remotely, with no in-person visits, and utilizes the EHR for participant identification and primary outcome collection.

Planetary Torus Helical Transmission

The paper describes design considerations for the transmission with fixed intermediate rolling bodies with grooves cut in a torus. Equations of helices used for cutting grooves have been derived. The transmission with the proposed design has a wide range of reduction ratios and small dimensions with high load capacity.

Designing and Fabrication of Switching High Voltage Power Supply for Nuclear Medicine Imaging Systems

This paper describes design considerations of the High voltage (HV) module with low ripple and good stability in order to improve the efficiency of nuclear imaging systems consist of Single Photon Emission Computed Tomography (SPECT). In the design of the current HV module, push-pull topology is preferred, due to the fact; it has a better efficiency in comparison with other technologies. The module receives a positive continuous voltage about 5-8 V as input, and provides a programmable positive or negative continuous voltage from 800-2500 V as output for a total load of 200-KΩ. The ripple of the output voltage is 10 mV that it is measured by laboratory equipment’s and safe high voltage (SHV) probe. The measured output power in the designed module is 25 W. Experiment results show that minimum efficiency at full load is around 65%. The proposed HV module shows a good stability, low ripple (noise), fast rise time. So, it can be used in SPECT or gamma camera imaging system to provide the constant voltage for PMTS.

Eddy current analysis and optimization of fast scanning magnet for a proton therapy system

Proton therapy is now recognized as one of the most effective radiation therapy methods for cancers. A proton therapy facility with multiple gantry treatment rooms is under development in HUST (Huazhong University of Science and Technology), which is based on isochronous superconducting cyclotron scheme. In the beam line, the scanning system spreads out the proton beam on the target according to the complex tumour shape by two scanning magnets for horizontal and vertical scanning independently. Since these two magnets are excited by alternating currents and the maximum repetition frequency is up to 100Hz, eddy currents and losses are expected to be significant. Slits are proven to be an effective way to reduce the eddy currents. To evaluate the heat distribution due to eddy losses in the pole end of the scanning magnet, the transient electromagnetic analysis and steady-state thermal analysis are performed. This paper describes design considerations of the scanning system and mainly analyses the eddy current effect of the scanning magnets. Different coil shapes and slit arrangements are simulated and compared to obtain the optimal configuration. The maximum temperatures of two magnets are optimized below 70°C. In addition, the lag effect due to eddy currents is also discussed.

Localization using GPS Coordinates in IPv6 Addresses of Wireless Sensor Network Nodes

Background/Objectives: This paper describes design considerations surrounding the implementation of a novel and standards-compliant scheme to incorporate GPS location information into the IPv6 address of Wireless Sensor Network (WSN) nodes. Methods/Statistical Analysis: A wide variety of localization protocols have been proposed which allow nodes to interpolate their location from their neighbors as an alternative to deploying more expensive WSN nodes with GPS receivers or other dedicated localization hardware. The scheme proposed here is similar to others in that it relies on ground-truth anchor nodes, and unique in that it uses the network address to convey this information. Findings: There are a number of interesting design considerations for location interpolation in a WSN that has a small number of sparsely distributed nodes with GPS ground-truth and a larger number of nodes that interpolate their location based on analysis of packets received with GPS coordinates and confidence intervals embedded in their addresses. Our calculations show that accurate GPS coordinates can be carried in the IPv6 address along with the transmission radius of the node, and this information is sufficient for a node to determine its location through triangulation. Additional flags can also be provided, such as an indicator of link quality, to refine this calculation and reduce the margin of error. The additional information can be different for each neighbor node, overcoming limitations on determining directionality in broadcast networks. Since the location information is carried in every packet header there is no overhead of a separate protocol and each node can do its calculations independently. Applications/Improvements: WSN nodes that report their geographic location in the address of every packet they send has obvious potential for refining information gathering in various types of deployments.

System Frequency as Information Carrier in AC Power Systems

Power generators contain control systems that are able to regulate system frequency, but the frequency setpoint values are rarely modified from nominal values. This paper describes design considerations for a communication system from generators to frequency-sensitive distributed energy resources (FS-DER) using changes to frequency setpoint values of generators. Signaling discrete system states by generating off-nominal system frequency values can be used as a novel narrowband unidirectional broadcast communications channel. This paper describes two protocols for utilizing off-nominal frequencies to carry information: First, a protocol for dispatching blocks of FS-DER that is suitable for systems restricted to relatively slow rates of change of frequency (ROCOF). Second, for systems that allow higher ROCOF values, the feasibility of using power generation resources as a power-line communication transmitter is shown. Data from an operating islanded power system with diesel generators are analyzed to demonstrate the feasibility of the proposed communication system in systems fed by rotating machines. The feasibility of the proposed communication system in systems fed by voltage-source inverters is shown with laboratory tests of a 20-kVA inverter. The inverter was found to have a maximum ROCOF of 2.2 Hz/s, sufficient to enable its use as a power-line communication transmitter.

Design considerations for point-of-care clinical trials comparing methadone and buprenorphine treatment for opioid dependence in pregnancy and for neonatal abstinence syndrome

RationaleIn recent years, the U.S. has experienced a significant increase in the prevalence of pregnant opioid-dependent women and of neonatal abstinence syndrome (NAS), which is caused by withdrawal from in-utero drug exposure. While methadone-maintenance currently is the standard of care for opioid dependence during pregnancy, research suggests that buprenorphine-maintenance may be associated with shorter infant hospital lengths of stay (LOS) relative to methadone-maintenance. There is no “gold standard” treatment for NAS but there is evidence that buprenorphine, relative to morphine or methadone, treatment may reduce LOS and length of treatment. DesignPoint-of-care clinical trial (POCCT) designs, maximizing external validity while reducing cost and complexity associated with classic randomized clinical trials, were selected for two planned trials to compare methadone to buprenorphine treatment for opioid dependence during pregnancy and for NAS. This paper describes design considerations for the Medication-assisted treatment for Opioid-dependent expecting Mothers (MOMs; estimated N=370) and Investigation of Narcotics for Ameliorating Neonatal abstinence syndrome on Time in hospital (INFANTs; estimated N=284) POCCTs, both of which are randomized, intent-to-treat, two-group trials. Outcomes would be obtained from participants' electronic health record at three participating hospitals. Additionally, a subset of infants in the INFANTs POCCT would be from mothers in the MOMs POCCT and, thus, potential interaction between medication treatment of mother and infant could be evaluated. ConclusionThis pair of planned POCCTs would evaluate the comparative effectiveness of treatments for opioid dependence during pregnancy and for NAS. The results could have a significant impact on practice.

Design Considerations for a Prosthetic Anterior Cruciate Ligament

Anterior cruciate ligament (ACL) tearing is a common knee injury often requiring reconstruction with an autograft or an allograft. A prosthetic ligament replacement with off-the-shelf availability could potentially provide significant advantages over the current options for both patients and surgeons. Limitations of previous prosthetics include lack of biocompatibility and susceptibility to fatigue, creep, and failure of bony incorporation. This paper describes design considerations and possible improvements for the next generation prosthetic ACL. Design controls, as mandated by the FDA, are a systematic set of practices within the design and development process used to ensure that a new medical device meets the needs of the intended users. The specified requirements, called the design inputs, for a prosthetic ACL are discussed pertaining to material and structural properties, resistance to creep and fatigue, ability to support secure initial fixation, biocompatibility, and long-term osseointegration. Design innovations to satisfy the design inputs are discussed with regards to material selection, textile pattern, bone tunnel features, and short term fixation. A risk analysis is presented along with descriptions of proposed testing. Design control methodology and tissue engineering may be used to develop a next generation prosthetic ligament, solving multiple problems, simultaneously, on a holistic level, providing major improvements over earlier devices and current treatment options.

Practical Considerations for a Digital Inductive-Switching DC/DC Converter With Direct Battery Connect in Deep Sub-Micron CMOS

This paper describes design considerations for a digital inductive-switching DC/DC converter suitable for direct battery connection in a deep sub-micron CMOS process. Digital control techniques and robust circuit design methods take advantage of the advanced process technology while avoiding the barriers to direct battery connection and high efficiency, high power density voltage conversion. The approach is verified on a prototype converter, implemented in 40 nm standard bulk CMOS. The design achieves a peak efficiency of 95% for an input range of up to 5.5 V. The transient response is optimized for typical mobile SoC operating conditions and achieves step response times as fast as 35 μs/V under load.

Experimental Investigation of Pattern Layout Effect on Radio-Frequency Performance of Thin-Film Silicon-on-Insulator Power Metal–Oxide–Semiconductor Field-Effect Transistors

This paper describes design considerations for the thin-film silicon-on-insulator power metal–oxide–semiconductor field-effect transistors for linear-amplification applications. The linear-amplification characteristics and DC performance depend on the grand interconnection pattern. We prefer to put the grand pattern on the drain (output) side. There are optimum finger lengths that provide the best linear amplification characteristics. The finger length also depends on the operating frequency and total gate width.

Design considerations and implementation of a DSP-based car-radio IF Processor

This paper describes design considerations and the implementation of a software defined radio receiver encompassing intermediate frequency (IF) digitization. The proposed system-on-chip performs the demodulation of both AM and FM stereo signals, digitized at the IF by means of a high dynamic range sigma-delta bandpass A/D converter. The chosen architecture combines hardware and software functions, trading flexible programmability with area occupancy. The software includes also true blind equalization of the FM signals, resulting in the rejection of the neighbor channels and of any other interfering signal, even under severe multipath conditions. The described chip, realized in a 0.18-/spl mu/m CMOS technology, occupies an area of 15.2 mm/sup 2/ and is enclosed in a 64-pin package.

Robotic stroke therapy assistant

The Rehabilitation Technologies Division of Applied Resources Corp. (RTD-ARC) has engaged in a Phase I effort to commercialize a robotic bi-manual therapy machine for use in stroke rehabilitation, in cooperation with the VA Rehabilitation R&D Center in Palo Alto. The robotic therapy device, called ARCMIME here in order to differentiate it from its clinical predecessor, has the potential to improve rehabilitation outcomes significantly for individuals who have upper limb impairments due to stroke and other brain injuries.This paper describes design considerations and clinical outcomes with regards to the Phase I system. It was found that the kinematically simpler system adequately replicated the data outcomes of the more sophisticated PUMA-based experimental test rig.

Tritium Processing and Tritium Laboratory in the International Fusion Materials Irradiation Facility (IFMIF)

ABSTRACTThis paper describes design considerations on the tritium processing and the tritium laboratory in the International Fusion Materials Irradiation Facility (IFMIF) that is being developed for neutron irradiation testing of candidate fusion materials. In the IFMIF the tritium is generated by various reactions. However, the irradiated materials will have high activities. The tritium processing method is designed on the basis of the evaluation for tritium source and generation rate. The tritium laboratory for post irradiation examination (PIE) of the activated/tritium contaminated materials is evaluated.

Smartfire: an Intelligent Cfd Based Fire Model

This paper describes a project aimed at making Computational Fluid Dynamics (CFD)- based fire simulation accessible to members of the fire safety engineering community. Over the past few years, the practice of CFD-based fire simulation has begun the transition from the confines of the research laboratory to the desk of the fire safety engineer. To a certain extent, this move has been driven by the demands of performance based building codes. However, while CFD modeling has many benefits over other forms of fire simulation, it requires a great deal of expertise on the user’s part to obtain reasonable simulation results. The project described in this paper, SMARTFIRE, aims to relieve some of this dependence on expertise so that users are less concerned with the details of CFD analysis and can concentrate on results. This aim is achieved by the use of an expert system component as part of the software suite which takes some of the expertise burden away from the user. SMARTFIRE also makes use of the latest developments in CFD technology in order to make the CFD analysis more efficient. This paper describes design considerations of the SMARTFIRE software, emphasizing its open architecture, CFD engine and knowledge-based systems.

An electrically isolated balanced wideband current source: basic considerations and design.

At relatively high frequencies, the application of an alternating current through the body or a body segment results in electromagnetic stray fields which reduce the amount of current actually injected into the tissue under study. This radiation effect can be reduced by use of a symmetrical configuration current source. The symmetry of such an arrangement, however, depends on the stray capacitances of the source with respect to surrounding equipment. To minimise these effects, it is required that the source is electrically isolated from the surrounding equipment and the subject under study. In this manner stray capacitances with respect to elements of the current source are reduced. In such a configuration common mode voltages to the input amplifier of the measuring system are also reduced. The paper describes design considerations and the implementation of a wideband current source capable of injecting alternating current in the order of 300 microARMS into biological tissue having impedances up to 1 k omega. Current stabilisation is obtained by means of a control circuit which measures the actual current passing through the tissue under study. Leakage currents arising from shielding and stray capacitances are compensated for. The usable frequency range is between 4 kHz and 1024 kHz and current stability is better than 0.2%. Through the use of a symmetrical, floating circuit a configuration is obtained which substantially reduces stray effects. The current source is connected to other circuits by means of two isolation ports: (1) a transformer coupling for the carrier frequency; and (2) an opto-coupler to transfer a phase reference signal obtained from current measurement. The current amplitude can be modulated by controlling the reference input to the control loop by means of a third auxiliary isolation port for transfer of the modulating signal.

An oscillator circuit for electrostatically driven silicon-based one-port resonators

This paper describes design considerations and characteristics of oscillator circuitry for electrostatically driven silicon-based one-port resonators, used as resonant strain gauges. The oscillation conditions for a general, single transconductance oscillator are theoretically derived. In order to start oscillation, guidelines to select proper bias conditions for the resonator are presented, taking the non-linear effects into account. An oscillator circuit has been designed in CMOS technology in order to verify the theory experimentally. Experimental results of the oscillator in combination with a silicon beam resonator are given.

A desktop computer-based workstation for display and analysis of 3- and 4-dimensional biomedical images

While great advances have been made in developing new and better ways to produce medical images, the technology to efficiently display and analyze them has lagged. This paper describes design considerations and development of a workstation based on an IBM PC/AT personal computer for the analysis of three- and four-dimensional medical image data.

Control Design of an Antenna Pointing Control System with Large On-Board Reflectors

This paper describes design considerations for the antenna pointing control system in ETS-VI. The satellite flexible structures including a 3.5-m main-reflector, a sub-reflector with an antenna pointing mechanism, and large solar paddles were modelled mathematically.The interactions between the satellite main body and antenna reflectors were estimated, and the structural model for application to control design was modified based on the results. By analizing the sensitivities of the control system parameters, it was clarified that the gain change of the control loop must be increased by about 3.6 dB taking the structural parameter variations into consideration.