Rural Facility Electric Power Quality Enhancement

Electric power disturbances are known to be more prevalent in small, isolated power systems than in larger interconnected grids which service most of the United States. This fact has given rise to a growing concern about the relative merits of different types of power conditioning equipment and their effectiveness in protecting sensitive electronics and essential loads in rural Alaska. A study has been conducted which compares isolation transformers, voltage regulators, power conditioners, uninterruptible power supplies and indoor computer surge suppressors in their ability to suppress the various disturbances which have been measured in several Alaskan communities. These include voltage sags and surges, impulses, blackouts, frequency variations and long-term voltage abnormalities. In addition, the devices were also subjected to fast, high-magnitude impulses such as might be expected in the event of a lightning strike to or near utility distribution equipment. The solutions for power line problems will vary for different load applications and for different rural electrical environments. The information presented in this report should prove to be valuable in making the analysis.List of Figures - viii List of Tables - xiv Acknowledgements - xv Chapter 1: Electric Disturbances in Power Systems Introduction - 16 Categorizing Electrical Disturbances - 17 Voltage Disturbances and Transients - 19 Frequency Disturbances - 22 Sources of Transients - 22 Lightning and EMP - 23 Switching - 24 Power System Noise - 25 Common Mode and Normal Mode Noise Signals - 26 Chapter 2: Power Quality in Rural Alaska Characterizing the Village Power System - 28 The Village Electric Load - 29 Power Quality Site Surveys - 30 Rural Power Quality in Alaska - 31 Power Conditioning Requirements for Village Loads - 37 Chapter 3: Isolation, Voltage Regulation and Power Conditioning Introduction - 39 Slow Voltage Fluctuations - 39 Voltage Regulation and Power Conditioning - 40 Ferroresonant Transformers - 40 Electronic Tap-Changing Regulators - 44 Isolation Transformers - 47 Dedicated Lines - 51 Chapter 4: Impulse Suppression Introduction - 52 Surge Suppressors - 52 Surge Suppressor Components - 55 Component Configuration - 58 EMI/RFI Filters - 58 Standard Tests for Evaluating Surge Suppressor Performance - 60 Scope of Impulse Testing for Rural Alaska - 60 Impulse Test Equipment - 62 Test Procedure - 62 Impulse Testing Measurements - 63 Test Results - 64 Chapter 5: Uninterruptible Power Supplies The True UPS - 68 Standby Power Systems and a New Generation of UPS - 69 UPS Backup Time - 74 UPS Testing - 74 Chapter 6: Computers and Power Problems Introduction - 78 The Computer Tolerance Envelope - 78 Ridethrough - 80 Component Degradation and Equipment Failure - 82 Computer Power Supplies - 82 Linear Power Supplies - 83 Switching Power Supplies - 84 PC Tolerance of Powerline Disturbances - 84 Chapter 7: Comparing Power Conditioning Alternatives Voltage Regulation - 89 Isolation - 93 Uninterruptible Power Systems - 94 Computer Surge Suppressors - 98 Summary - 98 Appendices Appendix A: Voltage Clamping Levels of Surge Suppressors - 101 Appendix B: Voltage Clamping Levels of Power Conditioners and Uninterruptible Power Systems - 115 Appendix C: Noise Suppression of Surge Suppressors and Power Conditioners - 129 Appendix D: Waveforms and Regulating Characteristics of Power Conditioners and Uninterruptible Power Systems - 135 Appendix E: Comparison of Voltage Clamping Levels of Surge Suppressors Power Conditioners, Isolation Transformers and Uninterruptible Power Systems to High-Magnitude Impulse Voltages - 151 References - 16

Recent advances in telemetry for estimating the energy metabolism of wild fishes

Metabolic rate is a critical factor in animal biology and ecology, providing an objective measure that can be used in attributing a cost to different activities and to assessing what animals do against some optimal behaviour. Ideally, metabolic rate would be estimated directly by measuring heat output but, until recently, this has not been easily tractable with shes so instead metabolic rate is usually esti- mated using indirect methods. In the laboratory, oxygen consumption rate is the indirect method most frequently used for estimating metabolic rate, but technical requirements preclude the measurement of either heat output or oxygen consumption rate in free-ranging shes. There are other eld methods for estimating metabolic rate that can be used with mammals and birds but, again, these cannot be used with shes. Here, the use of electronic devices that record body acceleration in three dimensions (accelerometry) is considered. Accelerometry is a comparatively new telemetric method for assessing energy metabolism in animals. Correlations between dynamic body acceleration (DBA) and oxygen consumption rate demonstrate that this will be a useful proxy for estimating activity-speci c energy expenditure from shes in mesocosm or eld studies over extended periods where other methods (e.g. oxygen consumption rate) are not feasible. DBA therefore has potential as a valuable tool for attribut- ing cost to different activities. This could help in gaining a full picture of how shes make energy-based trade-offs between different levels of activity when faced with con icting or competing demands aris- ing from increased and combined environmental stressors

Best practice for collar deployment of tri-axial accelerometers on a terrestrial quadruped to provide accurate measurement of body acceleration

Background: Tri-axial accelerometers are frequently deployed on terrestrial quadrupedal mammals using collars, because they are easy to fit and are thought to have minimal impact on the subject. Collar-attached devices are not fixed to the body and can move independently of the body. This may result in inaccurate measures of acceleration, reducing the accuracy of measured body movement. We determined the effect of collar size and collar weight on acceleration measured by a collar-mounted accelerometer on a quadruped mammal. The aim was to suggest best practice for sizes and weights of collars on which to deploy tri-axial accelerometers. Using pygmy goats, Capra aegagrus hircus, which were trained to walk at different speeds (0.8–3.0 km/h) on a treadmill, we measured body acceleration using a collar-mounted tri-axial accelerometer, with different collar sizes (individual neck circumference + 1 cm to + 9 cm) and collar weight (0.4% to 1.2% of individual weight). Results: There was a significant effect of collar size, collar weight and walking speed on measured acceleration. Measured acceleration was less accurate and more variable when collars were looser and heavier. To measure body acceleration more accurately, we found that collar size should be within 5 cm or 16% of an individual’s neck circumference when it was heavy (up to 1.2% of animal’s body weight) or within 7 cm (33%) of neck circumference if the collar was light (up to 0.6% of animal body weight). Conclusion: We suggest that not only reporting collar size and weight for welfare purposes, but it is also important to consider these aspects for scientific rigour, to ensure data are collected as accurately as possible. We provide guidelines for researchers fitting collar-attached devices to ensure a higher degree of accuracy of recorded body acceleration

Characterization of Surface Chromia Species on CrOx/TiO2 Catalysts

Titania supported chromia catalysts have been employed for selective catalytic reduction (SCR) process because of their higher activity and selectivity. The catalytic activity of the titania supported chromia system is owing to the stabilization of the anchored chromia species having multiple chemical and molecular states on the surface. In the present work an attempt has been made to prepare titania supported chromia catalysts, from TiCl4 and CrO3 as precursors for the support and active phase respectively. Characterization of the catalysts have been made using FTIR spectroscopy and thermo analytical techniques such as thermogravimetric analysis (TGA), evolved gas analysis (EGA) and temperature programmed reduction (TPR). The EGA, TGA and FTIR results indicate that the surface hydroxyl groups of TiO2 (gel) has an influence on the chemical state of the chromium. Due to the surface anchoring, Cr+5 species have been detected on the surface of the fresh catalyst which decomposes to lower valence state on calcination. EGA results indicate that Cr+3 species having higher degree of coordinatively unsaturated centers is stabilized by gel titania as support. EG analysis and FTIR studies illustrate the coverage of the surface with similar type of sites at 10 wt.% chromia loading. TPR studies demonstrate the presence different kinds of surface chromia species with respect to chromia content

Path Integral Variational Methods for Strongly Correlated Systems

We introduce a new approach to highly correlated systems which generalizes the Fermi Hypernetted Chain and Correlated Basis Function techniques. While the latter approaches can only be applied to systems for which a nonrelativistic wave function can be defined, the new approach is based on the variation of a trial hamiltonian within a path integral framework and thus can also be applied to relativistic and field theoretical problems. We derive a diagrammatic scheme for the new approach and show how a particular choice of the trial hamiltonian corresponds exactly to the use of a Jastrow correlated ansatz for the wave function in the Fermi Hypernetted Chain approach. We show how our new approach can be used to find upper bounds to ground state energies in systems which the FHNC cannot handle, including those described by an energy-dependent effective hamiltonian. We demonstrate our approach by applying it to a quantum field theoretical system of interacting pions and nucleons.Comment: 35 RevTeX pages, 7 separated ps figures available on reques

Evolution of Heat Flow, Hydrothermal Circulation and Permeability on the Young Southern Flank of the Costa Rica Rift

We analyze 67 new conductive heat flow measurements on the southern flank of the Costa Rica Rift (CRR). Heat flow measurements cover five sites ranging in oceanic crustal age between approximately 1.6 and 5.7 Ma, and are co-located with a high-resolution multi-channel seismic line that extends from slightly north of the first heat flow site (1.6 Ma) to beyond ODP Hole 504B in 6.9 Ma crust. For the five heat flow sites, the mean observed conductive heat flow is ≈ 85 mWm−2. This value is approximately 30 per cent of the mean lithospheric heat flux expected from a half-space conductive cooling model, indicating that hydrothermal processes account for about 70 per cent of the heat loss. The advective heat loss fraction varies from site to site and is explained by a combination of outcrop to outcrop circulation through exposed basement outcrops and discharge through faults. Super-critical convection in Layer 2A extrusives occurs between 1.6 and 3.5 Ma, and flow through a thinly-sedimented basement high occurs at 4.6 Ma. Advective heat loss diminishes rapidly between ≈ 4.5 and ≈ 5.7 Ma, which contrasts with plate cooling reference models that predict a significant deficit in conductive heat flow up to ages ≈ 65 ± 10 Ma. At ≈ 5.7 Ma the CRR topography is buried under sediment with an average thickness ≈ 150 m, and hydrothermal circulation in the basement becomes sub-critical or perhaps marginally critical. The absence of significant advective heat loss at ≈ 5.7 Ma at the CRR is thus a function of both burial of basement exposure under the sediment load and a reduction in basement permeability that possibly occurs as result of mineral precipitation and original permeability at the time of formation. Permeability is a non-monotonic function of age along the southern flank of the CRR, in general agreement with seismic velocity tomography interpretations that reflect variations in the degree of ridge-axis magma supply and tectonic extension. Hydrothermal circulation in the young oceanic crust at southern flank of CRR is affected by the interplay and complex interconnectedness of variations in permeability, sediment thickness, topographical structure, and tectonic and magmatic activities with age

Economics of integrated crop management systems in the Dark Brown Soil Zone

Non-Peer ReviewedLow commodity prices, rising input costs, and increasing concerns about environmental degradation are encouraging producers in western Canada to consider alternative soil tillage and weed management methods that conserve resource inputs. However, little is known about the economic merits of these management changes. This study determines the effects of six integrated soil, cultural, and weed management practices on production costs, economic returns, and riskiness for a Wheat (W)-Canola (C)-Barley (B)-Pea (P) rotation in the Dark Brown Soil Zone of Saskatchewan

Highlighting when animals expend excessive energy for travel using dynamic body acceleration

Travel represents a major cost for many animals so there should be selection pressure for it to be efficient – at minimum cost. However, animals sometimes exceed minimum travel costs for reasons that must be correspondingly important. We use Dynamic Body Acceleration (DBA), an acceleration-based metric, as a proxy for movement-based power, in tandem with vertical velocity (rate of change in depth) in a shark (Rhincodon typus) to derive the minimum estimated power required to swim at defined vertical velocities. We show how subtraction of measured DBA from the estimated minimum power for any given vertical velocity provides a “proxy for power above minimum” metric (PPAmin), highlighting when these animals travel above minimum power. We suggest that the adoption of this metric across species has value in identifying where and when animals are subject to compelling conditions that lead them to deviate from ostensibly judicious energy expenditure

From “where” and “when” to “what” and “why”: archival tags for monitoring “complex” behaviours in fish.

Understanding the movements (“where” and “when”) and behaviour (“what” and, hopefully, “why”) of individuals and populations is key to answering fundamental questions in fish ecology. The use of archival tags in telemetry studies of marine fish have, by and large, involved recording “simple” measurements of variables such as pressure (giving depth), temperature and light over extended timescales. These have then been used to provide information about location and movement of individuals. However, our understanding of more complex behaviours (i.e. what fish are doing as different from spatial movements) has usually been inferred from movement data because it has not been possible to record directly specific behavioural events such as feeding or spawning. This is because the events are usually infrequent, irregular and often quite brief and so not amenable to a technology based on taking regular but infrequent records of continuously available variables. The recent implementation of new sensors (e.g. physical movement, tri-axial accelerometers), rapid (< 30 Hz) sampling capabilities, enhanced memory and more complex data capture protocols has lead to the development of archival tags that can be used to detect and record complex behaviours such as feeding and spawning. We describe recent developments with archival tags and their use to monitor feeding and spawning in fish together with the application of tri-axial accelerometry that can be used to quantify behaviour and metabolic rate. These can then be used to assess the cost of behaviours with a view to understanding how appropriate they are as responses to environmental variability. Keywords: telemetry, behaviour, data storage ta