The Development and Application of Directional Comparison Protection for Series Compensated Transmission Systems

A new high speed Directional Comparison protection relay for capacitor compensated lines is described. It is shown that the special filtering and signal processing techniques developed overcome many difficult protection problems encountered on such lines. The relay design has been performed using computer-aided design (CAD) techniques and recent work on its implementation using a 16-bit bipolar microcomputer has been initiated. The latter indicates that the relay is readily implemented using present generation hardware.     

Testing Gbps interfaces without a gigahertz tester

As device manufacturers scale their silicon technology, and processor speeds rise above 1 GHz, it's becoming common for every processor company to tout gigahertz processors. To continually improve system-level performance, system designers have begun increasing I/O performance. Some of these changes are evolutionary; some are revolutionary. The latter necessitate a change in test methodology and in the subsequent DFT. Intel's changing its processors' front-side bus from common-clock to source-synchronous (SS) signaling and increasing their bus transfer rate from less than 100 MHz to 800 megatransfers/second (1 MT/s= 1 Mbyte/s/pin). On the chipset side, Intel has upgraded its universal serial bus from 48 Mbps to 400 Mbps and has transitioned to the serial advanced technology attachment (SATA) standard at a 1.25-Gbps data rate. we show how we've solved the testing problem of the SS interface and how this self-test scheme is extendable to other high-speed I/O circuits, including high-speed serial (HSS) signaling.     

Using CrAlN multilayer coatings to improve oxidation resistance of steel interconnects for solid oxide fuel cell stacks

The requirements of low-cost and high-temperature corrosion resistance for bipolar interconnect plates in solid oxide fuel cell stacks has directed attention to the use of metal plates with oxidation resistant coatings. The performance of steel plates with multilayer coatings, consisting of CrN for electrical conductivity and CrAlN for oxidation resistance, was investigated. The coatings were deposited using large area filtered arc deposition technology, and subsequently annealed in air for up to 25 hours at 800 °C. The composition, structure, and morphology of the coated plates were characterized using Rutherford backscattering, nuclear reaction analysis, atomic force microscopy, and transmission electron microscopy techniques. By altering the architecture of the layers within the coatings, the rate of oxidation was reduced by more than an order of magnitude. Electrical resistance was measured at room temperature. This paper was presented at the Fuel Cells: Materials, Processing, and Manufacturing Technologies Symposium sponsored by the Energy/Utilities Industrial Sector & Ground Transportation Industrial Sector and the Specialty Materials Critical Technologies Sector at the ASM International Materials Solutions Conference, October 13–15, 2003, in Pittsburgh, PA. The symposium was organized by P. Singh, Pacific Northwest National Laboratory, S.C. Deevi, Philip Morris USA, T. Armstrong, Oak Ridge National Laboratory, and T. Dubois, U.S. Army CECOM.     

PATTERNS OF FISH PASSAGE IN THE UPPER MISSISSIPPI RIVER

Dams have been implicated in the alteration of natural river processes. Quantifying spatial and temporal movement and passage patterns of large river fishes are critical for determining the extent of restricted passage and the needs for fish passage improvements. However, limited information regarding this topic exists because of the inherent difficulties associated with large river systems and assumptions associated with movement studies. Because of this lack of information, we investigated broad scale passage patterns of several riverine fish species through seven locks and dams complexes of the Upper Mississippi River using telemetry. Over the course of our 5‐year evaluation, we observed species‐specific movement and passage patterns, and how these trends were affected by factors such as water level and lock and dam management. Stationary receivers placed in a monitoring array detected a total of 1036 passage events. Eighty‐four percent of the passage occurred through all but one of the lock and dam structures during both open and closed river conditions. While 70% of the passage occurred during open river conditions, further investigation of passages that occurred during closed river conditions (when gates are extended into the water column at some level) revealed that the majority of passage occurred when the average opening for all gates ranged from 0.6 to 1.2 m. Lock usage was also quantified, and most species were not routinely using the lock chambers for passage. Ultimately, these data have shown that individuals of each study species were able to negotiate most of the locks and dams during open and closed river conditions in both directions. Copyright © 2013 John Wiley & Sons, Ltd.     

Optimization and Rapid Prototyping of Catadioptric Omnidirectional Stereo Sensors

Omnidirectional stereo imaging provides useful depth information for autonomous navigation. In principle, omnidirectional stereo images can be achieved at a low cost, using a single camera and two curved mirrors, but such systems are not widely deployed. Here we describe the optimization and rapid prototyping of a low-cost omnidirectional stereo sensor for a telepresence robot. We consider single-viewpoint and non-single-viewpoint designs. We present a new way of relaxing single-viewpoint constraints, while retaining the ability to vertically rectify images. We also present a method of optimizing the resulting design to minimize depth errors. However, we show that despite these steps, nonsingle-viewpoint designs produce stereo disparities over a more practical range of distances. The lack of a single viewpoint could potentially introduce distortions that affect stereo matching, but these distortions are removed by projecting rays through the mirror geometry. We also describe a new method for rapid prototyping of curved mirrors using 3D printing and vacuum forming.     

Identification of fatty acid polymorphic modifications by infrared spectroscopy

IR spectra in the 7.5–25.0 μ region are shown to be unique for the individual long chain odd carbon numbered saturated fatty acids and for the monounsaturated even carbon numbered fatty acids, their isomers, and polymorphic modifications. IR spectra are presented which illustrate similarites and dissimilarities resulting from chain length differences and polymorphic variations for monounsaturated acids. X-ray crystal long spacings for the saturated odd carbon numbered acids are compared with literature values. X-ray crystal long spacings for monounsaturatedtrans acids are shown to be related to carbon chain length and independent of the location of unsaturation. Diffractograms and IR spectra of the 2 polymorphic modifications of elaidic acids are presented. IR spectra illustrating band differences forcis andtrans isomers are shown. ARS, USDA.     

+Gz acceleration loss of consciousness: time course of performance deficits with repeated experience

OBJECTIVES: We examine the time course of performance recovery from gravity-induced loss of consciousness (GLOC) and evaluate the utility of exposing participants to repeated bouts of GLOC in promoting recovery time. BACKGROUND: A substantial number of accidents among fighter pilots have resulted from episodes of GLOC. U.S. Air Force doctrine holds that when pilots experience GLOC, impairment lasts for 24 s, in which there are 12 s of complete unconsciousness and 12 s of confusion. However, there is reason to suspect that performance efficiency associated with GLOC is degraded well before unconsciousness sets in and that more than 24 s are required for performance efficiency to return to baseline levels. Additionally, there is a belief that repeated exposure to GLOC will reduce recovery time. METHOD: Centrifuge simulators were used to induce GLOC in U.S. Air Force personnel with math and tracking tasks employed to emulate flight performance. Participants were tested once per week for 4 consecutive weeks. RESULTS: On average, performance deficits appeared 7.44 s prior to the onset of unconsciousness and persisted for 55.6 s following the GLOC event. Repeated exposure failed to moderate these results. CONCLUSION: The temporal course of performance deficits produced by GLOC far exceeds prior estimates. The problem is more serious than previously envisioned and it is not alleviated by repeated exposure to GLOC. APPLICATION: U.S. Air Force doctrine regarding the severity of GLOC and the utility of repeated exposure to this problem needs to be revised and these data incorporated into future aircraft auto recovery systems.     

The influence of storage on the fatty acid content of cod liver oil

Summary A study has been made of the change of fatty acid content of cod liver oils during storage. Thirty oils varying in acid content from 0.38% to 20.88% were procured in the open market. They represented three types of oils—medicinal, animal feeding and industrial oils. The samples of oil were stored at room temperature, in the dark, in three-fourths filled, four-ounce, amber, cork-stoppered bottles. The acid content was determined twelve times during a period of forty-two months. The acid content of each oil increased. The amount of increase varied from 7.42% for a sample of industrial oil with an initial acid content of 16.45% to 84.80% for a sample of animal feeding oil with an initial acid content of 0.99%. In general, the cod liver oils with initial high acid content showed a lower percentage increase in free fatty acids than oils with a low initial free fatty acid content.     

RFID tag readability issues with palletized loads of consumer goods

Radio Frequency Identification (RFID) is an automatic identification technology, relying on storing and remotely retrieving data using devices called RFID tags. This technology is being used in enterprise supply chain management‐related applications to improve the efficiency of inventory tracking and management. However, this technology has not been able to realize its promised potential because of several factors, such as lack of congruous worldwide standards, privacy issues and less than perfect read rates in supply chain applications. This research aimed to evaluate the readability issues commonly faced by tagged cases of palletized consumer products. The variables studied in this research were product‐package type, tag type, tag location on cases, pallet pattern and forklift speed through a RFID portal representative of a dock door in a warehouse. To determine which variables were the most significant, a binary logistic regression was run. The number of tags read was inputted for the number of events and total number of products per pallet as the number of trials. The variables product content, pallet pattern, and speed, and all interactions were then included in the model. It was observed that readability greatly varies for different product‐package systems, with paper towels producing near‐perfect reads, followed by bottled water and carbonated soda cans. The slower the forklift truck speed, the better the readability across the board, and the best pallet patterns were dependent on the product‐package type. For bottled water, the best pallet pattern was column, and for carbonated soda, the interlocking pattern. Copyright © 2009 John Wiley & Sons, Ltd.     

Fish Assemblage and Ecosystem Metabolism Responses to Reconnection of the Bird's Point‐New Madrid Floodway during the 2011 Mississippi River Flood

Understanding the ecological function of developed large rivers remains elusive because these systems have long been altered for multiple uses. In particular, floodplains of large rivers, such as the Mississippi River, have been contained behind extensive levees. A historic flood occurred in the lower Mississippi River system during spring of 2011, prompting the US Army Corps of Engineers to activate the Bird's Point‐New Madrid floodway, a 55 000‐ha, agriculturally dominated, leveed area. Water entered the floodway at flows >1 m s^?1 through two crevasses created in the upper portion of the levee and exited through a crevasse at the lower end. During the month, the floodway was inundated; we quantified discharge, water chemistry, primary production and fish production in the floodway and the adjacent river. Water entering the floodway was retained <1.3 d, and nutrient concentrations were not elevated in the floodway beyond those in the river, despite expected contributions from a legacy of fertilization. Primary production equaled respiration in the floodway, while the adjacent river was heterotrophic. Gizzard shad and freshwater drum were more abundant in the floodway than the river, while channel catfish were more abundant in the river. Growth rates of young native fishes, normalized for temperature, were the same in the floodway and the river, with the exception of gizzard shad, which grew faster in the floodway. Fish community structure, especially in the lower floodway, was temporally and spatially dynamic. Even though it has been heavily modified for agriculture, the floodway provided benefits, albeit limited, to the Mississippi River. With multifunctional management and strategic planning, systems such as these may provide substantial services such as flood abatement, nutrient transformation and fish production in the Mississippi River basin and potentially reduce nutrient loading downstream in areas such as the Gulf of Mexico. Copyright © 2015 John Wiley & Sons, Ltd.