Critical Performance Parameters Research Articles

Benchmarking of DPL-based 8b × 8b novel wave-pipelined multiplier

ABSTRACTThe present study examines double pass-transistor logic (DPL) and evaluates the performance of a proposed DPL-based 8b × 8b wave-pipelined pair-wise multiplier. It then compares some of its critical performance-parameters with a Normal-Process-Complementary-Pass-transistor-Logic (NPCPL) based design. Double transmission properties with balanced input capacitance of DPL gate, is the focus of the present work to improve multiplier performance like throughput and noise margin at reduced supply. In DPL both N-type and P-type devices help balanced transmission of logic ‘1’ and logic ‘0’ that in turn reduces data-dependent delay variation, and is therefore suitable for time equalised applications. Pulse-triggered TSPC (true single phase clocking) flip-flop (PTTFF) is once again used to design I/O registers of the multiplier for the advantages already stated in the previous work. The design is optimised and validated on TSMC-0.18 µm single-poly double-metal (SPDM) CMOS technology at 25°C temperature. Parameters for comparison include power-dissipation, throughput, latency, area and noise-margin under 2 V, 1.8 V and 1.5 V supply.

Evaluation of thiol-ene photo-curable resins using in rapid prototyping

Purpose The purpose of this paper is to evaluate the properties of several thiol-acrylate photosensitive systems and compare with corresponding acrylate free-radical systems. The potential stereolithography applications of thiol–ene photosensitive systems are also discussed. Design/methodology/approach In the both thiol–ene and acrylate free-radical photosensitive systems, various key performances were characterized. The function group conversions were characterized by real-time Fourier transform infrared spectroscopy. The tension strength was determined according to the standard ASTM D638-2003, the flexible strength was determined according to ASTM D790-07 and the hardness was measured according to ASTM D2240-05. The volume shrinkage was measured by dilatometer method. The glass transition temperature was analyzed by differential scanning calorimeter. Findings As adding mercapto propionates into acrylate system, the inhibition of polymerization by oxygen was controlled and the flexible performance was improved. In addition, the photosensitive resin showed better tension strength, higher elongation at break and lower volume shrinkage. Among the four mercapto propionates, rigid TEMPIC showed most obvious affect, followed hexa-functional DPMP, tetra-functional PETMP and tri-functional TMMP. Originality/value Although the thiol–ene photosensitive resin has unmatched advantages in performance, there are no reports on the thiol–ene photosensitive resin in the stereolithography application. In this study, thiol–ene photopolymerization material was first tentatively implemented in stereolithography area. Several critical performance parameters were compared between thiol–ene and acrylate free-radical photosensitive systems.

Built-In Self-Test and Digital Calibration of Zero-IF RF Transceivers

We propose a self-test method for zero-IF radio frequency transceivers using primarily loopback, aided by a small built-in self-test (BIST) circuitry, to determine critical performance parameters, such as I/Q imbalance and nonlinearity coefficients. The transceiver is placed in the loopback mode by couplers, specifically designed to be asymmetric with respect to the primary path and the BIST path. The loopback path is also designed to include two traces with slightly different delays to enable parameter deembedding. Transceiver parameters are analytically computed using baseband I and Q signals over two frames, each of which is 200 μs in duration. Overall, measurement time is <;10 ms, including computation time. In addition to loopback hardware support and the associated parameter deembedding methodology, we propose a complimentary BIST circuit to measure the transmitter (TX) gain. The measured parameters can be used for predistortion or postdistortion to calibrate the transceiver, both at production time and in the field. Both simulation and hardware measurement results show that the proposed method can determine the target performance parameters with adequate accuracy for digital calibration. Measurement and the subsequent calibration are shown to reduce TX error vector magnitude more than fivefold, even for significantly impaired systems.

Rheological and molecular weight comparisons of approved hyaluronic acid products – preliminary standards for establishing class III medical device equivalence

Hyaluronic acid of various molecular weights has been in use for the treatment of osteoarthritis knee pain for decades. Worldwide, these products are regulated as either as drugs or devices and in some countries as both. In the US, this class of products is regulated as Class III medical devices, which places specific regulatory requirements on developers of these materials under a Pre-Market Approval process, typically requiring data from prospective randomized controlled clinical studies. In 1984 pharmaceutical manufacturers became able to file an Abbreviated New Drug Application for approval of a generic drug, thus establishing standards for demonstrating equivalence to an existing chemical entity. Recently, the first biosimilar, or ‘generic biologic’, was approved. Biosimilars are biological products that are approved by the FDA because they are ‘highly similar’ to a reference product, and have been shown to have no clinically meaningful differences from the reference product. For devices, Class II medical devices have a pathway for declaring equivalence to an existing product by filing a 510 k application for FDA clearance. However, until recently no equivalent regulatory pathway was available to Class III devices. In this paper, we consider the critical mechanical performance parameters for intra-articular hyaluronic products to demonstrate indistinguishable characteristics. Analogous to the aforementioned pathways that allow for a demonstration of equivalence, we examine these parameters for an existing, marketed device and compare molecular weight and rheological properties of multiple batches of a similar product. We propose that this establishes a scientific rationale for establishing Class III medical device equivalence.

Use of next generation sequencing data to develop a qPCR method for specific detection of EU-unauthorized genetically modified Bacillus subtilis overproducing riboflavin.

BackgroundRecently, the presence of an unauthorized genetically modified (GM) Bacillus subtilis bacterium overproducing vitamin B2 in a feed additive was notified by the Rapid Alert System for Food and Feed (RASFF). This has demonstrated that a contamination by a GM micro-organism (GMM) may occur in feed additives and has confronted for the first time,the enforcement laboratories with this type of RASFF. As no sequence information of this GMM nor any specific detection or identification method was available, Next GenerationSequencing (NGS) was used to generate sequence information. However, NGS data analysis often requires appropriate tools, involving bioinformatics expertise which is not alwayspresent in the average enforcement laboratory. This hampers the use of this technology to rapidly obtain critical sequence information in order to be able to develop a specific qPCRdetection method.MethodsData generated by NGS were exploited using a simple BLAST approach. A TaqMan® qPCR method was developed and tested on isolated bacterial strains and on the feed additive directly.ResultsIn this study, a very simple strategy based on the common BLAST tools that can be used by any enforcement lab without profound bioinformatics expertise, was successfully used toanalyse the B. subtilis data generated by NGS. The results were used to design and assess a new TaqMan® qPCR method, specifically detecting this GM vitamin B2 overproducing bacterium. The method complies with EU critical performance parameters for specificity, sensitivity, PCR efficiency and repeatability. The VitB2-UGM method also could detect the B. subtilis strain in genomic DNA extracted from the feed additive, without prior culturing step.ConclusionsThe proposed method, provides a crucial tool for specifically and rapidly identifying this unauthorized GM bacterium in food and feed additives by enforcement laboratories. Moreover, this work can be seen as a case study to substantiate how the use of NGS data can offer an added value to easily gain access to sequence information needed to develop qPCR methods to detect unknown andunauthorized GMO in food and feed.Electronic supplementary materialThe online version of this article (doi:10.1186/s12896-015-0216-y) contains supplementary material, which is available to authorized users.

Mesoscale Modeling and Simulation of Composition, Manufacturing, and Microstructure Effects on Electrical Conduction in Thermal Battery Cathodes

Li/FeS2 thermal batteries provide a stable, robust, and reliable power source capable of long-term electrical energy storage without performance degradation. These systems rely on the electrical conductivity of FeS2 cathodes for critical performance parameters such as power and lifetime, and on permeability of the electrolyte through the solid FeS2 particles for ion transfer. The effects of component composition, manufacturing conditions, and the mechanical deformation on conductivity and permeability have not been studied. We present simulation results from a finite element computer model compared with impedance spectroscopy electrical conductivity experiments. Our methods elucidate the combined effects of slumping, particle size distribution, composition, and pellet density on properties related to electrical conduction in Li/FeS2 thermal battery cathodes.

Life Cycle Environmental Implications of CO2 Capture and Sequestration with Ionic Liquid 1-Butyl-3-methylimidazolium Acetate

In this paper, for the first time, we present findings on the life cycle environmental implications of an ionic liquid (1-butyl-3-methylimidazolium acetate, [bmim]+[Ac]−)-based carbon capture and sequestration (CCS) process retrofitted to a coal-fired power plant. Ionic liquids are considered as promising alternative solvents to currently proven technology based on monoethanolamine (MEA). The results indicate that a CCS process with 90% CO2 capture efficiency based on [bmim]+[Ac]− reduces life cycle greenhouse gas (GHG) emissions by only 50%. This does not compare favorably with 75% life cycle GHG reductions offered by the MEA-based CCS process. In depth analysis reveals that despite lower total energy requirements for the ionic liquid process the increased need for electricity results in poor environmental performance. The insights gained from the results of the ionic liquid [bmim]+[Ac]− CCS process is used to explore critical life cycle environmental performance parameters and trade-offs in the context of future design of functionalized ionic liquids for CO2 capture. This work will aid energy system and policy analysts to understand the full implications of future ionic liquid-based CCS systems.

Forecast of Performance Parameters of Automotive Fuel Cell Systems – Delphi Study Results

AbstractFuel cells are a promising propulsion technology option in sustainable and zero‐emission drivetrain strategies as they offer a high potential to significantly reduce well‐to‐wheel greenhouse gas emissions and the dependency on fossil energy resources. At the same time, the current technological performance of automotive fuel cell systems is not yet sufficient to meet market demands. Therefore, the technical development of fuel cells is a critical factor for a successful market introduction of fuel cell electric vehicles (FCEV). This paper describes the methodology and results of a two‐round Delphi Survey conducted by the Institut für Kraftfahrzeuge of RWTH Aachen University to assess the technological potential of polymer electrolyte membrane fuel cell (PEMFC) systems in automotive applications by 2030. The analysis of the current and future performance level of key performance indicators (KPI) of automotive fuel cell systems helps to identify critical performance parameters and to prioritize research and development demands. KPI analyzed in the Delphi Survey as forecast parameters include system efficiency, durability, power density, and specific power.

Optimal Test Droplets Dispensing for Parallel Testing for Digital Microfluidic Biochip

Digital microfluidic systems (DMFS) are an emerging class of lab-on-chip systems. They become widespread in safety-critical biomedical applications, and dependability is a critical performance parameter for them. For most parallel test schemes, the test droplets are preloaded into their test region before the start of testing, and the time needed for transferring the test droplets to their corresponding test region that called the dispensing time may be very long. To reduce dispensing time, an optimal test droplets dispensing for parallel testing is proposed in the paper. The problem that we address here is to minimize the system testing time by optimally assigning test droplets dispending to the test sources. Even though the decision version of the problem is shown to be NP-complete, it can be solved exactly for practical instances using integer linear programming (ILP). The experimental results show the effective of the proposed test scheme.

Invited Presentation: US DOE Battery R&D Progress related to Electric Drive Vehicles

The Department of Energy’s Vehicle Technology Office (DOE VTO) is focused on funding high-reward/high-risk research by national laboratories, universities, and industry – to develop low-cost and high-performance batteries necessary for the broad consumer acceptance of hybrid and plug-in electric vehicles (PEV) in the marketplace. In fiscal year 2013 (FY 2013), the DOE VTO battery R&D funding totaled about $88 million. The status of current battery technologies for transportation applications, especially lithium-ion technologies, will be highlighted in this talk and the associated issues will be discussed. Current battery technology performance lies very far below its theoretically possible limit. In the near-term, even for existing lithium-ion technology, there is an opportunity to more than double the battery pack specific energy (from 100 Wh/kg to 250 Wh/kg) by using new high-capacity cathode materials, higher voltage electrolytes, and by replacing graphite anodes with high capacity silicon or tin-based intermetallic alloys. Despite recent promising advances, much more R&D is needed to achieve performance and lifetime requirements necessary for their successful deployment in PEVs. In the longer term, certain “beyond Li-ion” battery chemistries (e.g., lithium-sulfur, magnesium-ion, zinc-air, lithium-air, and other advanced chemistries) offer the possibility of specific energy values significantly higher than those of current lithium-ion batteries and they also show the potential for significantly reducing the battery cost. However, certain major shortcomings in the areas of cycle life, power density, energy efficiency, and/or other critical performance parameters; along with cost, currently hinder the commercial introduction of such “beyond Li-ion” battery systems. Therefore, innovative breakthroughs are needed for these new battery technologies to enter the market. This paper summarizes VTO-supported battery R&D projects for FY 2013 and provides a progress update on them. The research directions being pursued by VTO to develop next-generation lithium-ion batteries and beyond are described, along with a discussion of the current focus on materials development.Figure: Battery manufacturers derived the above cost projections by using the USABC’s battery manufacturing cost model and assuming an annual production volume of 100,000 batteries per year (for validated battery cell and module designs, meeting DOE/USABC requirements for power, energy, and cycle life).

Estimation of Critical Performance Parameters of the Thermocouple in a Bypass Device, Made of SME Alloy, Designed for LIABs on Spacecraft

Critical parameters of the bypass device thermocouple made of SME alloy are optimized on the base of the developed thermal model of Lithium-Ion storage battery (LISB) for space applications. It is shown that the terminal is the most dangerous element within LIAB. To ensure LIAB reliability in case of one cell failure, a temperature limit in the vicinity of the terminal is set to 100°C, and the bypass device action time – to 2–3 s, which corresponds to phase transitions temperature range of the thermocouple spring made of SME alloy.

Sensitivity of the vitellogenin assay to diagnose exposure of fathead minnows to 17α-ethynylestradiol

Vitellogenin is frequently used as a biomarker of exposure to environmental estrogens due to its specificity and sensitivity. Appropriate incorporation of this biomarker into environmental monitoring and assessment necessitates evaluation of its critical performance parameters. In this study, we characterize the sensitivity of both vitellogenin gene (vtg) mRNA transcripts in liver and protein (VTG) in plasma over a range of concentrations and exposure durations. Male fathead minnows were exposed to 17α-ethynylestradiol (EE2) in a flow-through system for 2, 4 and 7 days at multiple EE2 concentrations in order to provide information regarding the sensitivity of each of these biomarkers to diagnose exposure to this representative estrogen. Measurements of the expression of the vitellogenin gene and protein both reliably detected exposures to EE2 at concentrations of 5ng/l and higher at all time points. Vtg mRNA and plasma VTG appear to have similar sensitivities, though the lower variability in VTG in control fish may make it more sensitive to small changes in expression compared to vtg. For lower concentrations, sensitivity may be improved by increasing exposure duration. A sample size of ∼12 fish was sufficient in many cases to produce a statistically significant increase in vitellogenin. Larger sample sizes may provide more sensitivity at low concentrations, but detecting exposure to estrogens in the lower range of environmentally relevant concentrations may need larger sample sizes. These data will assist in designing experiments that have sufficient statistical power necessary to determine if fish have been exposed to estrogens.

A Method for Systematic Electrochemical and Electrophysiological Evaluation of Neural Recording Electrodes

New materials and designs for neural implants are typically tested separately, with a demonstration of performance but without reference to other implant characteristics. This precludes a rational selection of a particular implant as optimal for a particular application and the development of new materials based on the most critical performance parameters. This article develops a protocol for in vitro and in vivo testing of neural recording electrodes. Recommended parameters for electrochemical and electrophysiological testing are documented with the key steps and potential issues discussed. This method eliminates or reduces the impact of many systematic errors present in simpler in vivo testing paradigms, especially variations in electrode/neuron distance and between animal models. The result is a strong correlation between the critical in vitro and in vivo responses, such as impedance and signal-to-noise ratio. This protocol can easily be adapted to test other electrode materials and designs. The in vitro techniques can be expanded to any other nondestructive method to determine further important performance indicators. The principles used for the surgical approach in the auditory pathway can also be modified to other neural regions or tissue.

All-Optical XOR Gate Using Single Quantum-Dot SOA and Optical Filter

In this paper, we propose to implement an all-optical XOR gate for 160 Gb/s return-to-zero data signals using a single quantum-dot semiconductor optical amplifier (QD-SOA) assisted by a detuned optical filter (OF). These two elements are connected in series in a probe-dual pump configuration. By conducting numerical simulations, we thoroughly investigate and assess the impact of the critical performance parameters on the Q <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> -factor. The analysis of the obtained results against this metric enables us to specify the data signals peak power, QD-SOA small signal gain, current density, electron relaxation time from the excited state to the ground state and linewidth enhancement factor, and OF detuning, bandwidth and shape, for which the XOR logic is executed at the target data format and rate both with logical correctness and high quality. The confirmation of its design feasibility combined with its simplicity and ultrafast capability makes the XOR gate scheme promising for exploitation in all-optical signal processing and switching applications.

Optimal Design of Broadband and Large Dynamic Range IF AGC Circuit

The bandwidth and the dynamic range is the critical performance parameter of IF AGC (Intermediate Frequency Automatic Gain Control) in wireless receiver. In order to design broadband and large dynamic range IF AGC circuit, the main functions and performance of the VGA (Variable Gain Amplifier) AD8367 and the logarithmic amplifier AD8318 are analyzed. A kind of a broadband large dynamic range IF AGC module is designed by using these two chips. Detail circuit is provided; key technology of AGC module is analyzed and the actual testing results are offered. Compared to the traditional AGC circuit, the module is simple; it has small size and obvious advantages in broadband and large dynamic range.

An Improved Insulation System for the LHC Main 13 kA Interconnection Splices

In 2013, a long shutdown of the Large Hadron Collider at CERN will allow comprehensive maintenance plus consolidation of the machine components, in particular of the 13 kA circuits that feed the main superconducting magnets around the 27-km ring. This shutdown will prepare the accelerator for operation at nominal energy, 14 TeV, with adequate margin on the critical performance parameters. An essential part of the consolidation program consists of adding to the 13 kA splices of the magnet interconnects a copper shunt of high RRR(> 300) that will carry the current in the event of a busbar quench. An important R&D program was conducted in 2010 to design a sound solution for the shunt and for an improved insulation system. The development of the insulation system has required iterations aiming at an adequate solution. The functional requirements for the insulation are a breakdown voltage of at least 3.1 kV in superfluid helium and sufficient mechanical strength to withstand stresses of the order of 50 MPa. The insulation system shall provide mechanical restraint for the shunted splices so that their transversal deflection is limited to 0.25 mm. This paper describes the final design of the insulation and the optimization process. The results from dielectric tests and numerical optimization of the insulation cover will be also presented. Finally, the performance of the new insulation will be compared to the previous version.

Contact Physics of Capacitive Interconnects

The resistance and capacitance of a typical multipoint contact interface have been used to assess the impact on high-frequency signal integrity. In the past, it has been shown how fully degraded interfaces could still provide acceptable performance for signal transfers at high data rates. In the case of fully degraded contacts, signals were shown to transfer by capacitive coupling and wave propagation. This paper focuses on the critical parameters of a capacitive-coupled interface. Moreover, the physics of the contact interface is related to contacts that rely on capacitive (as opposed to metallic) coupling and electronic tunneling. These results help define the physics and design requirements for capacitive coupling. In addition, critical performance parameters such as real contact area, film thickness, and the nature of dielectric films are defined for high-frequency signal propagation. This paper provides a contrast between the requirements for high-frequency signal transfer using capacitive coupling and electron tunneling versus traditional metallic contact.

Relationships Between Ground Reaction Impulse and Sprint Acceleration Performance in Team Sport Athletes

Large horizontal acceleration in short sprints is a critical performance parameter for many team sport athletes. It is often stated that producing large horizontal impulse at each ground contact is essential for high short sprint performance, but the optimal pattern of horizontal and vertical impulses is not well understood, especially when the sprints are initiated from a standing start. This study was an investigation of the relationships between ground reaction impulses and sprint acceleration performance from a standing start in team sport athletes. Thirty physically active young men with team sport background performed 10-m sprint from a standing start, whereas sprint time and ground reaction forces were recorded during the first ground contact and at 8 m from the start. Associations between sprint time and ground reaction impulses (normalized to body mass) were determined by a Pearson's correlation coefficient (r) analysis. The 10-m sprint time was significantly (p < 0.01) correlated with net horizontal impulse (r = -0.52) and propulsive impulse (r = -0.66) measured at 8 m from the start. No significant correlations were found between sprint time and impulses recorded during the first ground contact after the start. These results suggest that applying ground reaction impulse in a more horizontal direction is important for sprint acceleration from a standing start. This is consistent with the hypothesis of training to increase net horizontal impulse production using sled towing or using elastic resistance devices, which needs to be validated by future longitudinal training studies.

Directed evolution of a 13-hydroperoxide lyase (CYP74B) for improved process performance

The performance of a 13-hydroperoxide lyase from guava, an enzyme of the CYP74 family, which is of interest for the industrial production of saturated and unsaturated C6-aldehydes and their derivatives, was improved by directed evolution. Four rounds of gene shuffling and random mutagenesis improved the functional expression in E. coli by offering a 15-fold higher product yield factor. The increased product yield factor relates to an improved total turnover number of the variant enzyme, which also showed higher solubility and increased heme content. Thermal stability was also dramatically improved even though there was no direct selection pressure applied for evolving this trait. A structure based sequence alignment with the recently solved allene oxide synthase of Arabidopsis thaliana showed that most amino acid alterations occurred on the surface of the protein, distant of the active site and often outside of secondary structures. These results demonstrate the power of directed evolution for improving a complex trait such as the total turnover number of a cytochrome P450, a critical parameter for process performance that is difficult to predict even with good structural information at hand.

Distributed Landsilde Mornitoring by Wireless Sensor Nodes

Wireless Sensor network (WSN) is an emerging technology widely applied in environmental disasters monitoring. With the constraint of computation resource, it face big challenge of stability and reliability of monitoring network. A statistical model of strain data and distributed monitoring algorithm for landslide based on WSN is studied in this paper. The strain data is modeled using variable mean of Gaussian process. Miss alarm rate and false alarm rate are introduced as critical performance parameters of landslide prediction. Comparing with centralized monitoring method, simulation result shows that distributed monitoring algorithm performs better than centralized monitoring.