1,202 research outputs found
Active rc filter permits easy trade-off of amplifier gain and sensitivity to gain
Passive RC network was designed with zeros of transmission in the right half of the complex frequency plane in the feedback loop of a simple negative-gain amplifier. The proper positioning provides any desired trade-off between amplifier gain and sensitivity to amplifier gain
Architecting Integrated System Health Management for Airworthiness
Integrated System Health Management (ISHM) for Unmanned Aerial Systems (UAS) has been a new area of research - seeking to provide situational awareness to mission and maintenance operations, and for improved decision-making with increased self-autonomy. This research effort developed an analytic architecture and an associated discrete-event simulation using Arena to investigate the potential benefits of ISHM implementation onboard an UAS. The objective of this research is two-fold: firstly, to achieve continued airworthiness by investigating the potential extension of UAS expected lifetime through ISHM implementation, and secondly, to reduce life cycle costs by implementing a Condition-Based Maintenance (CBM) policy with better failure predictions made possible with ISHM. Through a series of design experiments, it was shown that ISHM presented the most cost-effective improvement over baseline systems in situations where the reliability of the UAS is poor (relative to manned systems) and the baseline sensor exhibited poor qualities in terms of missed detection and false alarm rates. From the simulation results of the test scenarios, it was observed that failure occurrence rates, sensor quality characteristics and ISHM performance specifications were significant factors in determining the output responses of the model. The desired outcome of this research seeks to provide potential designers with top-level performance specifications of an ISHM system based on specified airworthiness and maintenance requirements for the envisaged ISHM-enabled UAS
Conductivity of Paired Composite Fermions
We develop a phenomenological description of the nu=5/2 quantum Hall state in
which the Halperin-Lee-Read theory of the half-filled Landau level is combined
with a p-wave pairing interaction between composite fermions (CFs). The
electromagnetic response functions for the resulting mean-field superconducting
state of the CFs are calculated and used in an RPA calculation of the q and
omega dependent longitudinal conductivity of the physical electrons, a quantity
which can be measured experimentally
Tunable bandpass filter with variable selectivity
Basic active RC networks constructed from stages that realize second-order transfer functions using two integrators offer excellent stability. Modifications of the basic network produce a highly stable bandpass filter having separate controls that independently adjust center frequency, Q, and center frequency gain
Early oral-motor interventions for pediatric feeding problems: What, when and how
Children with developmental delays often have feeding difficulties resulting from oral-motor problems. Based on both clinical experience and a review of published studies, oral-motor interventions have been shown to be effective in improving the oral function of preterm infants and children with neuromotor disorders, such as cerebral palsy. However, oral-motor problems may be under identified in other populations of children with developmental difficulties. The purpose of this paper is to provide a conceptual framework for understanding oral-motor skill development and problems that can occur in any infant and young child and to review oral-motor treatment techniques and their empirical support
Development of integrated thermionic circuits for high-temperature applications
Integrated thermionic circuits (ITC) capable of extended operation in ambient temperatures up to 500 C are studied. A set of practical design and performance equations is demonstrated. Experimental results are discussed in which both devices and simple circuits were successfully operated in 5000 C environments for extended periods. It is suggested that ITC's may become an important technology for high temperature instrumentation and control systems in geothermal and other high temperature environments
Developing a Circular Economy for the Data Centre Industry – how the CEDaCI project contributes to sustainable decision making
Data centres (DCs) house data processing and storage equipment. The data centre industry (DCI) is evolving rapidly, as society is becoming more dependent on digital technologies. Currently, there are 7.2 million DCs globally and provision is predicted to grow fivefold by 2030. The sector already utilises millions of tonnes of resources, including Critical Raw Materials, and the demand will only increase. DCI is based on a linear economy; recycling and materials reclamation infrastructure are also inadequate. At the end-of-life, many materials are either lost to landfill, incinerated, or unaccounted for. Furthermore, many virgin materials are located in geopolitically sensitive locations, which poses a threat to the supply chain that the sector relies on. The CEDaCI project aims to increase overall sectoral sustainability by addressing the various technical, cultural, and behavioural barriers across the DCI, such as fragmentation and sole focus on the energy efficiency. This paper describes the whole-systems approach and CEDaCI project outputs, including bespoke Eco-design guidelines, strategies, and digital tools to extend product life and recycling, and enable better decision-making to increase circularity in the DCI, prepare and support the implementation of the EU Circular Economy Action Plan and ensure a secure, sustainable resource supply chain
DOUBLE KNEE BEND IN THE POWER CLEAN
The power clean is well established as the “gold standard” exercise for the development of lower extremity propulsive forces (Garhammer, 1982). The power clean has become a sprint specific strength and conditioning exercise, which is incorporated into periodised training programmes (Siff, 1992). Specifically the occurrence of a double knee bend (DKB) provides a mechanism to elicit a sprint specific stretch shortening cycle (SSC), maximising power output (Enoka, 1979). The aim of this exploratory study was to investigate whether the DKB occurred in power cleans as relative load increased
Simulation and Economic Modelling of a Floating Solar Photovoltaic (FSPV) System using PVSyst
This paper examines the economic feasibility of implementing a Floating Solar Photovoltaic (FSPV) system in a Philippine Lake using the PVsyst simulation tool. The study involved a detailed simulation of the FSPV system's performance, considering various environmental and technical parameters. Key aspects such as system configuration, energy yield, and financial metrics including payback period and net present value were analyzed. Results indicate that the FSPV system could significantly contribute to local energy needs while proving to be a financially viable investment due to substantial reductions in CO2 emissions and lower energy costs compared to traditional power sources. According to assessments and simulations performed using PVSyst software, the FSPV system would possess a capacity of 10 kWp, with an expected available energy output of 13,599 kWh per year and an expected energy consumption of 12,940 kWh per year. The economic modeling of the FSPV system revealed a relatively short payback period of 4.8 years, with a net present value of Php 741,732.00 and a substantial return on investment of 227.5%. The Levelized Cost of Energy (LCOE) was estimated at Php 6.18 per kWh. The study underscores the potential of FSPV systems to meet the renewable energy needs of isolated communities by leveraging local water bodies for solar installations
Current Trends, Advancements, and Challenges in Floating Solar Photovoltaic (FSPV) Systems for Off-Grid Applications: A Review
Increasing energy demands and the pursuit of sustainable and clean energy sources have intensified interest in Floating Solar Photovoltaic (FSPV) systems, particularly for off-grid applications. FSPV technology presents a strategic alternative for countries with limited land but ample water bodies, contributing to energy diversification and conservation of arable land. This paper provides a comprehensive technological trends, advancements, and challenges in the deployment of FSPV systems, drawing from an array of highly regarded publications and extensive patent searches via the Derwent Innovation database and various publications. While large-scale FSPV deployments have been successfully integrated with existing hydroelectric power plants and grid systems, the application of FSPV technology for local community use remains underexplored. The paper identifies the lack of comprehensive literature on stand-alone FSPV systems that include battery charging capabilities and integrated monitoring and control systems to mitigate environmental risks. Moreover, the paper discusses the economic, regulatory, technical, cultural, and environmental barriers to FSPV deployment. It suggests that continuous research and development, backed by supportive policy frameworks, are crucial for overcoming these challenges. The aim is to pave the way for resilient, community-centric FSPV installations that can withstand extreme weather and cater to localized energy needs
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