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Investigation of high rate mechanical properties and damage evolution in porcine liver tissueChen, Joseph 07 August 2010 (has links)
Each year, 6.4 million automobile accidents account for approximately 40,000 deaths in the United States. With increasing requirements for automobile safety, computational models capable of simulating organ deformation/ injury during high impact scenarios would be extremely valuable for optimizing safety measures. Accurate experimental data is essential for the accuracy of the models; however, there has been a sparse investigation into high-strain biomechanics which is necessary to address organ/tissue response in high impact scenarios. Damage threshold criterion and damage evolution are other areas that have not been well studied. In vehicular accidents, damage to the liver is the most common cause of death after abdominal injury. High fidelity computational modeling with damage predictor is thus capable of describing liver tissue that is subjected to blunt impact. In this study, we address high strain biomechanics and damage evolution of liver tissue in an effort to generate valuable meaningful FE models.
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The effect of anoxic selectors on the control of activated sludge bulking and foamingMangrum, Carl Robert Lawrence II 10 December 1998 (has links)
Laboratory scale activated sludge experiments were conducted on primary effluent municipal wastewater to evaluate the effects of anoxic selectors on controlling activated sludge bulking and foaming. These experiments were conducted with two pilot plants; a three stage anoxic selector preceding a complete mix system (experimental unit) and a complete mix system (control unit). Successful selector operation requires balancing two conflicting requirements; obtain a high substrate concentration in the selector while achieving a high substrate removal efficiency in the selector. The high substrate concentration enables rapid substrate uptake to occur predominately by floc forming microorganisms while the high substrate removal efficiency ensures that a feed-starve cycle is created whereby filamentous microorganisms are selected against.
The reported metabolic mechanisms responsible for substrate uptake in the selector are the formation of internal storage products and high rate metabolism. As presented by Jenkins et al., (1993) small amounts of substrate are oxidized in the selector during the formation of internal storage products. Hence, large quantities of substrate can be removed while reducing only small amounts of the terminal electron acceptor. The internal stores are metabolized in the main biological reactor only after the exogenous substrate has been exhausted. High rate metabolism in the selector results in larger amounts of substrate oxidation. Consequently, for successful selector operation large quantities of the terminal electron acceptor must be reduced.
The anoxic selector pilot unit successfully reduced activated sludge settleability and biological foams relative to the control unit. Results from this study indicate that the mode of substrate removal was influenced by the initial selector floc load. This is in general agreement with the findings by Goel and Gaudy (1968) and Gaudy and Gaudy (1988) on oxidative assimilation in activated sludge treatment. The floc load depicts the instantaneous organic loading in the selector irrespective of hydraulic retention time. Results from this study further indicate that for lower floc loadings substrate storage is predominate. Alternatively, at higher floc loadings high rate substrate metabolism is predominate. Therefore, it is hypothesized that for selector zones with high enough F/M ratios to promote rapid substrate uptake, the mechanism predominately responsible for substrate removal is influenced by the floc loading. / Master of Science
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COMPUTER-FRIENDLY HIGH RATE DIGITAL CASSETTE RECORDERSKayes, Edwin A. 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / The world of instrumentation data recording has traditionally been concerned with
recorder performance in terms of bandwidth, data rate, tape speed and recording time, with
the apparently unceasing trend to record more and more data.
However, while this may remain a valid perspective for data acquisition, the increasing
requirement to integrate equipment into computer based environments has resulted in the
need for greater emphasis to be applied to such parameters as data control and interfacing
when specifying digital data recording systems.
This paper addresses these operational issues and describes the practical implementation
of a computer friendly digital cassette recorder which provides a common platform for
both high rate data acquisition and computer based data analysis.
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A DESKTOP SATELLITE DATA PROCESSING SYSTEMBrown, Barbie, Ghuman, Parminder, Medina, Johnny, Wilke, Randy 10 1900 (has links)
International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The international space community, including National Aeronautics and Space
Administration (NASA), European Space Agency (ESA), Japanese National Space
Agency (NASDA) and others, are committed to using the Consultative Committee for
Space Data Systems (CCSDS) recommendations for low earth orbiting satellites. With the
advent of the CCSDS standards and the availability of direct broadcast data from a number
of current and future spacecraft, a large number of users could have access to earth science
data. However, to allow for the largest possible user base, the cost of processing this data
must be as low as possible.
By utilizing Very Large Scale Integration (VLSI) Application-Specific Integrated Circuits
(ASIC), pipelined data processing, and advanced software development technology and
tools, highly integrated CCSDS data processing can be attained in a single desktop system.
This paper describes a prototype desktop system based on the Peripheral Component
Interconnect (PCI) bus that performs CCSDS standard frame synchronization, bit
transition density decoding, Cyclical Redundancy Check (CRC) error checking, Reed-Solomon decoding, data unit sorting, packet extraction, annotation and other CCSDS
service processing. Also discussed is software technology used to increase the flexibility
and usability of the desktop system. The reproduction cost for the system described is less
than 1/8th the current cost of commercially available CCSDS data processing systems.
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Combined speech and audio coding with bit rate and bandwidth scalabilityFarrugia, Maria January 2001 (has links)
The past two decades have witnessed a rapid expansion within the telecommunications industry. This growth has been primarily motivated by the proliferation of digital communication systems and services which have become easily available through wired and wireless systems. Current research trends involve the integration of speech, audio, video and data channels into true multimedia communications over fixed and mobile networks. However, while the available bandwidth in wired terrestrial networks is relatively cheap and expandable, it becomes a limited resource in satellite and cellular-radio systems. In order to accommodate an ever growing number of users while maintaining high quality and low operational costs, it is necessary to maximise spectral efficiency. This has given rise to the development of high rate compression techniques with the ability to adapt to a broad class of input signals and to varying network resources. The research carried out in this thesis has mainly focused on the design of a single algorithm for compressing speech and audio signals sampled at different rates. The algorithms are based on the analysis-by-synthesis linear prediction coding (AbS-LPC) scheme, which has been widely employed in various speech coding standards. However, this bit rate reduction technique is based on the speech production mechanism and as such provides a rigid structure which presents a major limitation for audio coding. In order to improve the audio quality at low rates and to compensate for the errors incurred by the linear prediction during segments of high transitions, the algorithms employ an efficient pulse excitation structure which represents the short innovation sequences with sparse unit magnitude pulses. The scheme proposed for the compression of telephone bandwidth speech and audio signals at 12kb/s achieves similar quality to the G.728 coder at 16kb/s and higher audio quality than the GSM-EFR standard at 12.2kb/s. Wideband speech and audio coding schemes have been designed using both the fullband approach at bit rates of 17 and 19kb/s and also the split band technique at a bit rate of 20kb/s. The perceptual quality is comparable to the G.722 coder operating at 48kb/s. The subband decomposition technique is also adapted to code speech and audio signals sampled at 32kHz. The quality of the coder at 28kb/s is similar to the quality achieved by the MP3 coder at 32kb/s. The algorithm also provides bandwidth and bit rate scalability ranging from 12 to 64kb/s, making it ideal for deployment in rate-adaptive communication systems.
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A PERSONAL TELEMETRY STATIONHui, Yang, Shanzhong, Li, Qishan, Zhang 10 1900 (has links)
International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / In this paper, a PCM telemetry system based on Personal computer is presented and
some important methods that are used to realize the system will be introduced, such as
a new kind of all digital PLL bit synchronizer and a way to solve the problem of high-rate
data storage.
The main idea of ours is to make the basic parts of PCM telemetry system (except
receiver) in the form of PC cards compatible with EISA Bus, which forms a
telemetry station with resource of PC computer.
Finally, a laboratory prototype with rate up to 3.2Mbps is built.
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A CCSDS Compatible High-Rate Telemetry Formatter for Space ApplicationBarringer, Bruce O. 11 1900 (has links)
International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / OSC is presently developing a high-rate telemetry collection and formatting component for NASA's EOS-AM1 spacecraft. This device, called the Science Formatting Equipment, is capable of collecting data at aggregate rates exceeding 130 Mbps. The collected data is formatted into CCSDS compatible data structures, error coded, and then routed either to a downlink output or to a recording device at data rates up to 150 Mbps. This paper serves as a brief introduction to this component.
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Flockning och förtjockning i High-Rate-förtjockare – en jämförelse med konventionell förtjockarteknik och lamellsedimentering.Östlind, Per January 2006 (has links)
In the process laboratory of Metso minerals (Sala) AB, continuous tests have been made with a laboratory unit High-Rate thickener. The tests are made in order to compare three methods of thickening techniques of suspended solids. The three techniques are High-Rate thickening, conventional thickening and lamella thickening. The High-Rate and the conventional trials are based on a continuous method, while the lamella thickener is based on batch trials. Because the lamella thickener is based on batch trials and there were some optimization problems with the adding point of the flocculant at the continuous trials, it was not feasible to compare the lamella thickener with the other two thickener types. On the other hand, since the optimization problems were the same for the other two methods there was no problem comparing them. The result of the comparison between the High-Rate thickener and the conventional thickener, was, that the High-Rate thickener manages to work at a higher rise rate with a lower consumption of flocculant than the conventional thickener. Seeing to the unit area that is needed by each thickener it is apparent that the conventional thickener demands a higher unit area than the High-Rate thickener to achieve the same amount of solids in the underflow. It has also been showed that the High-Rate thickener demands a lesser quantity of flocculant at the same amount of suspended solids in the feed than the conventional thickener.
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Enhancing the performance of wastewater microalgae through chemical and physical modifications in High Rate Algal PondsSutherland, Donna Lee January 2015 (has links)
High rate algal ponds (HRAPs) are an advanced pond that provide efficient and cost-effective wastewater treatment, as well as the ability to recover nutrients in the form of microalgal biomass. Microalgal photosynthesis, nutrient uptake and subsequent growth, coupled with aerobic bacteria degradation of organic compounds, are fundamental to the process of wastewater treatment in HRAPs, yet are often limited in these ponds and, in particular, microalgal photosynthesis is well below the reported theoretical maximum. Understanding how the physico-chemical environment affects microalgal performance is therefore critical to improved wastewater treatment and nutrient recovery, yet has been the subject to few studies to date. This research focused on the enhancement of microalgal photo-physiology, growth and nutrient removal efficiency (NRE) through modification to the physical and chemical environment in wastewater HRAPs. In this study, I first examined the seasonal dynamics of microalgal performance in full-scale wastewater HRAPs. While both retention-time corrected chlorophyll biomass and photosynthetic potential increased from winter to summer, the summer-time performance was considered to be constrained, as indicated by the decreased light absorption, light conversion efficiency and NRE. The physico-chemical environment in the full-scale HRAPs were characterised by high day-time pH, high light attenuation and long, straight channels with low turbulence. This led to questions regarding 1) effects of nutrient supply, in particular carbon and 2) the role of the HRAP light climate on microalgal performance. I addressed these questions using a series of experiments that involved either changing the nutrient concentration and its supply or by modifying the light environment, through changes in pond operational parameters including CO2 addition, influent dilution, pond depth, hydraulic retention time (HRT), mixing speed and frequency. The overall results from these experiments showed that carbon was the primary and light the secondary limiting factors of microalgal performance. These limitations negatively affected light absorption, photosynthesis, productivity and NRE. While each operational parameter tested impacted on microalgal performance, to some degree, CO2 addition had the greatest influence on light absorption, photosynthetic efficiency and productivity, while continuous mixing had the greatest effect on NRE. Adding CO2 increased light absorption by 110% and 128%, maximum rate of photosynthesis by 185% and 218% and microalgal biovolume by between 150 – 256% and 260 – 660% (species specific), when cultures were maintained at pH 8 and 6.5, respectively. Providing sufficient mixing to achieve continuous turbulence enhanced NRE by between 300 – 425% (species specific), increased biomass concentrations between 150% and 4000% (species specific) compared to intermittent and no mixing, respectively, and increased harvest-ability of colonial species. However, at present, both CO2 addition and mechanical mixing attract high capital and operational costs. Modification to these technologies would be required to meet the objectives of cost-effective wastewater treatment and biofuel production. A more immediate and cost-effective solution demonstrated in this study was the altering pond depth, influent concentration and HRT. Doubling pond depth from 200 to 400 mm increased both microalgal nutrient removal and photosynthetic efficiencies which led to areal productivity increasing by up to 200%. When increased pond depth was coupled with decreased HRT, light absorption and photosynthetic performance further increased due to decreased internal self-shading and improved pond light climate. For nutrients, high influent loads increased productivity, while moderate loads increased effluent water quality. Overall, this work demonstrated that optimising the chemical and physical environment of wastewater treatment HRAPs (CO2 addition to maintain pH at 6.5 – 7, 400 mm pond depth, continuous mixing with vertical speed of 200 mm s-1, moderate nutrient load (15- 30 g m-3) and moderate HRT (4 / 6 days summer / autumn) can enhance microalgal biomass productivity, nutrient recovery as well as improve effluent water quality, particularly during summer when growth can be constrained.
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Implementing Space Link Extension (SLE) for Very High Rate Space LinksLokshin, Kirill, Puri, Amit, Irvin, Dana, Ross, Frank, Rush, Rebecca 10 1900 (has links)
ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, California / Space Link Extension (SLE) is a set of recommended standards for mission cross support developed by the Consultative Committee for Space Data Systems (CCSDS). The SLE recommendations define protocols for extending the space link from ground terminals to other facilities deeper within a ground network, allowing distributed access to space link telecommand and telemetry services. The SLE protocols are widely used to provide cross support between sites, programs, and agencies. Traditional SLE protocol implementations have been limited in their ability to support high data rates and large numbers of concurrent service instances. Such limited solutions were sufficient to support the needs of spacecraft health and status or older, low-rate science data. More recent missions, however, have required significantly increased data rates on both uplink and downlink paths, necessitating a new approach to SLE implementation. This paper discusses the design principles involved in implementing the SLE protocols in support of high channel and aggregate mission data rates, with particular focus on the tradeoffs necessary to provide SLE link capability at sustained single-channel rates above 1 Gigabit per second. The paper addresses significant performance bottlenecks in the conventional SLE protocol stack and proposes potential mitigation strategies for them.
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