The Effect of Dry Needling to the Multifidus Muscle on Resting and Contracted Thickness of Transversus Abdominis in Subjects with Low Back Pain

Study Design: Randomized, double-blinded, controlled clinical trial. Objective: To measure the effects of dry needling to the lumbar multifidus (MF) muscle for any change in resting and contracted thickness of the transversus abdominis (TrA) muscle as well as symptoms and disability in individuals with low back pain (LBP). Background: Recent studies have demonstrated that individuals with LBP have diminished co-activation of the lumbar MF and TrA muscles, which when working appropriately in healthy individuals, contributes to spinal stability and function. A significant change in the resting and contracted thickness of TrA has been found with dry needling to the lumbar MF in healthy subjects, but this has yet to be studied in individuals with low back pain. Methods: Thirty adults with LBP were randomly assigned to receive dry needling intervention or a sham needling intervention to the lumbar MF. The participants received instruction on the deep corset contraction (DCC) for purposes of measuring TrA muscle relaxation and contracted thickness with real time ultrasound (US) imaging pre- and post-intervention. Along with the US measurements, the Oswestry Disability Index (ODI), the Global Rating of Change Scale (GROC) and the Numeric Pain Rating Scale (NPRS) were used to measure outcomes at baseline, immediately post-, 2-days post, and 7-days post intervention. (See pdf for full abstract

The RIPE NCC internet measurement data repository

This paper describes datasets that will shortly be made available to the research community through an Internet measurement data repository operated by the RIPE NCC. The datasets include measurements collected by RIPE NCC projects, packet trace sets recovered from the defunct NLANR website and datasets collected and currently hosted by other research institutions. This work aims to raise awareness of these datasets amongst researchers and to promote discussion about possible changes to the data collection processes to ensure that the measurements are relevant and useful to the community

The Modern Day Corporation: A Philosophical Analysis of How Corporations Behave and How They Should Behave

We seem to hold corporations to an impossible standard. We call for profit maximization, but at the same time want to place strict limits on the methods corporations may use to obtain them. In this thesis, I explore two popular theories of the corporation: stakeholder theory and shareholder theory. I examine the degree to which each theory explains the corporation as it exists today, as defined in the law and through its behavior, but also the theories‘ normative appeal. I conclude by positing what I find to be the best normative account of the corporation: a theory of how we should structure the corporation in the United States so it is the most morally-defensible

Development and Characterization of Lithium Indium Diselenide for Neutron Detection and Imaging Applications

Lithium indium diselenide [LISe] is under development as a single crystal semiconductor detector for neutron detection applications. Enriched in lithium-6, a neutron sensitive isotope, this wide-band gap semiconductor possesses the inherent neutron-gamma discrimination afforded by the thermal neutron capture reaction energy while providing distinct efficiency advantages over lithiated conversion layer detectors. The overarching theme of this work is to characterize the fundamental properties of this material to optimize its performance in neutron detection applications. The work presented here includes the identification of a suitable metallurgical contact for advanced detector fabrication, fundamental electronic property characterization, and proof-of-principle fast neutron imaging performance. Candidate contact materials were deposited through radio frequency magnetron sputtering. The primary metrics used to identify a robust contact were adhesion to the LISe surface and current voltage characteristics. Among the numerous contacts investigated, indium demonstrated the best adhesion properties. Its viability was demonstrated through the fabrication of a pixelated thermal neutron imaging detector (LTNI). Charge generation, transport, and trapping properties were investigated with emphasis on the stability of these properties post-operation in high thermal neutron flux fields. Neutron and alpha spectroscopy, photoinduced current transient spectroscopy, Raman spectroscopy, trap-filled limited voltage, and photoconductivity measurements were used to probe the charge transport and trapping mechanisms. Moderate transport properties were identified with respect to comparable technologies. Defect studies demonstrated that the type and density of defects strongly influenced performance of the detector. Encouraged by the performance of LTNI, an imaging detector was fabricated by coupling a LISe crystal to a 256 x 256 channel Timepix Application Specific Integrated Circuit to maximize spatial resolution. The fast neutron spatial resolution for 9MeV [electron-Volts] neutrons was investigated via a knife edge experiment. The measured efficiency was in agreement with the Evaluated Nuclear Data File cross-section database. The ultimate spatial resolution of the system was determined as 1.55 millimeters via the 10-90% decrease in contrast of the one-dimensional edge spread function. In conclusion, this material has been shown to exhibit suitable properties warranting further development for high efficiency slow neutron applications guided by the results of this work

Waste heat driven turbo-compression cooling

2018 Spring.Includes bibliographical references.Waste heat recovery systems utilize exhaust heat from power generation systems to produce mechanical work, provide cooling, or create high temperature thermal energy. One waste heat recovery application is to use the exhaust heat from a Natural Gas Combined Cycle Power Plant (NGCC) to drive a heat activated cooling system that can offset a portion of the plant condenser load. There are several heat activated cooling systems available including absorption, adsorption, ORVC, and ejector, but each has disadvantages. One system that can overcome the disadvantages of typical heat activated cooling systems is a turbo-compression cooling system (TCCS). In this system, the exhaust heat enters an organic Rankine cycle at the boiler and vaporizes the fluid that passes through a turbine. The turbine power is directly transferred to a compressor via a hermetically sealed shaft that is made possible by a magnetic coupling. The compressor operates a vapor-compression system which provides a cooling effect in the evaporator. The hermetic seal between the turbine and compressor allows for two separate fluids on the power and cooling cycles, which maximizes the efficiency of the turbine and compressor simultaneously. This study presents a thermodynamic modeling approach that makes system performance predictions for the baseline design case, and for off-design performance conditions. The off-design modeling approach uses turbo-compressor performance maps and a heat exchanger UA scaling methodology to accurately simulate system operation for a broad range of temperatures and cooling loads. A 250 kWth cooling capacity TCCS was constructed and tested to validate the modeling approach. The test facility simulates a 138:1 scaled NGCC power plant configuration in which the TCCS extracts 106°C waste heat from the flue gases and produces a cooling effect that offsets a portion of the NGCC condenser load. The design target for the test facility was to achieve a COP of 2.1 while chilling water from 17.2°C to 16°C at an ambient temperature of 15°C. Although the final design point was not tested for this study due to facility limitations, the off-design performance methodology was utilized to predict the performance for an ambient condition of 27.5°C and power and cooling cycle mass flow rate range between 0.35 kg s-1 - 0.5 kg s-1 and 0.65 kg s-1 – 0.85 kg s-1, respectively. The comparison between the experimental and modeling data suggested strong correlation over the data range presented with a maximum error in COP of only 2.0% among the selected data points. Future experimental data over a larger range of ambient temperatures and system conditions is suggested to further validate the system modeling. Regardless, the results in the present study show that the TCCS compares favorably with other heat activated cooling systems

Gravitational radiation timescales for extreme mass ratio inspirals

The capture and inspiral of compact stellar masses into massive black holes is an important source of low-frequency gravitational waves (with frequencies of ~1-100mHz), such as those that might be detected by the planned Laser Interferometer Space Antenna (LISA). Simulations of stellar clusters designed to study this problem typically rely on simple treatments of the black hole encounter which neglect some important features of orbits around black holes, such as the minimum radii of stable, non-plunging orbits. Incorporating an accurate representation of the orbital dynamics near a black hole has been avoided due to the large computational overhead. This paper provides new, more accurate, expressions for the energy and angular momentum lost by a compact object during a parabolic encounter with a non-spinning black hole, and the subsequent inspiral lifetime. These results improve on the Keplerian expressions which are now commonly used and will allow efficient computational simulations to be performed that account for the relativistic nature of the spacetime around the central black hole in the system.Comment: 19 pages, 4 figures. Changed in response to referee's report. Accepted for publication in Astrophysical Journa