bluuebunny/crossref_metadata_2025 huggingface dataset:
The Role of Fuel Cells for Consumer Electronic Products and Toys
Authors: Banazwski B. , Shah R. K.
Published: January 2009

Batteries have not kept pace with the advancing technology that they power, but they are used in everything from cell phones, laptop computers, and toys to consumer electronics. Compared to the devices that they power, batteries are relatively heavy, expensive per unit power they produce, last a relatively short time and recharging them takes hours. The solution to this less than desired means of a power source is fuel cells. Three fuel cells, also referred to as air breathers, considered are proton exchange membrane fuel cell (PEMFC), direct methanol fuel cells (DMFC), and direct formic acid fuel cells (DFAFC). We will discuss these fuel cells for micro and portable applications within the power range of 0.5 to 20 W for potential replacement of batteries. The reason for developing such fuel cells is to harness the power stored in the high energy density fuels, which provides more power and longer run times for the same packaging volume as batteries. The advantages of each type of fuel cell over batteries, their unique characteristics, technical drawbacks, current and future consumer products, and commercial issues will be outlined in this paper. A growing mobile society and consumer demands will drive the development of fuel cell technology forward as batteries reach their limit.
The Role of High Performance Foil Bearings in Advanced, Oil-Free, High-Speed Motor Driven Compressors
Authors: Walton James F. , Tomaszewski Michael J. , Heshmat H.
Published: January 2009

The demand for high power density, reliable, low maintenance, oil-free turbomachinery imposes significant demands on the bearing system. The full benefits of high speed, motor driven machines, for example are realized at speeds exceeding the capabilities of rolling element bearings. The high speeds, and requirement for oil-free operation in fuel cell applications also make conventional liquid lubricated bearings an undesirable alternative. The modern, oil-free foil bearing provides an excellent alternative, with its low power loss, damping for smooth high-speed operation and shock tolerance, elevated temperature capability and long maintenance free life. In this paper, the application of modern foil bearings to two different high-speed, oil-free compressors is discussed. In each application, foil bearings support a multi-component rotor operating at speeds above 70,000 RPM. Stable and reliable operation over the full speed range is demonstrated in each case. These applications also required low bearing start-up torque for compatibility with the torque characteristics of the integral motor. This work discusses the rotor bearing system design, the development program approach, and the results of testing to date.
Initial Results From an Experimental Hybrid Solar Lighting System in a Commercial Building and Overview of Related Value Propositions
Authors: Muhs Jeff , Earl Duncan , Beshears Dave , Maxey Curt
Published: January 2009

This paper describes preliminary results from research on a new hybrid solar lighting (HSL) system being developed to reduce electric lighting in commercial office buildings. A physical description of HSL system components along with preliminary results from an experimental system deployed in a commercial building in Knoxville, TN are provided. Results from a systems-level, chromaticity model are compared with experimental data. A total lumen distribution efficiency of over 50% was recorded for the initial prototype having optical fibers an average of 6 m (19.5 ft) in length. The total electrical power displacement of the 1 m2 HSL proof-of-concept prototype is estimated to be between 522–2350 watts per 1000 W/m2 of incident solar radiation on the collector depending on the type of electric lights being used in conjunction with the solar lighting system. By adding the reductions in heat gain associated with reduced electric lamp use and predicted performance improvements achieved by a system redesign, the electrical power displaced in a commercial prototype could rise to between 702–3160 W (peak)/m2 of collected sunlight not including any additional electrical power that can be generated using the otherwise wasted IR energy. The color temperature of the distributed sunlight emerging from the optical fibers is approximately 5100°K and the chromaticity values in uniform color space (u′v′) are approximately (.2010, .4977). These values match well with modeled results and will vary slightly depending on the day, time, atmospheric conditions, and system configuration. The paper concludes with a discussion of new value propositions that HSL provides architects, energy providers, building owners, and occupants and briefly outlines anticipated disadvantages.
Development of a Fan Airflow Station for Airflow Control in VAV Systems
Authors: Yuill David P. , Redmann Nathan K. , Liu Mingsheng
Published: January 2009

A fan airflow station has been developed by the authors. This station is used to determine fan airflow using fan speed and fan head as inputs. These inputs can be measured accurately in variable air volume (VAV) systems, so they can be used as a cost-effective control monitoring method for heating, ventilation and air conditioning (HVAC) systems. Theoretical models have been developed for the flow station using both second and third order relationships between the airflow and the inputs. The theoretical model has been experimentally tested and excellent agreement between the model and the experimental values was found. The second order model was within 1.71% of the experimental values, and the third order model was within 1.52%. The second order model, which is much simpler, is considered adequate for use in buildings.
The Immobilisation of Flue Gas Treatment Residues Through the Use of a Single Staged Wash and Crystalline Matrix Encapsulation (CME) Treatment Process
Authors: Robertson Daniel , Burnley Stephen , Barratt Rod
Published: January 2009

All incineration and other thermal treatment technologies produce flue gas treatment residues (FGTR) that require specialised treatment and disposal. In the United Kingdom the FGTR arising from municipal solid waste incineration is classified as a hazardous (special) waste. This is primarily due to the irritant properties of chloride, but also due to the content of heavy metals. These wastes must be handled, transported & disposed of in accordance with the Special Waste Regulations 1996 and are disposed into highly engineered landfill sites, which isolate the material from the environment. The low levels of trace elements in the FGTR mean that the recycling of the metallic elements is not economic. Control through stabilisation and encapsulation in a crystalline matrix converts the FGTR primary form from a powder into solid block form. The use of a novel metal matrix encapsulation (MME) process allows low level engineering processes to be employed, increasing a range of reuse options combined with long-term improved storage.
The Numerical Simulation of LNG Sloshing With an Improved Volume of Fluid Method
Authors: Loots Erwin , Pastoor Wouter , Buchner Bas , Tveitnes Trym
Published: January 2009

With the trend towards offshore LNG production and offloading, sloshing of LNG in partially filled tanks has become an important research subject for the offshore industry. LNG sloshing can induce impact pressures on the containment system and can affect the motions of the LNG carrier. So far, LNG sloshing was mainly studied using model tests with an oscillation tank. However, the development of Navier-Stokes solvers with a detailed handling of the free surface, nowadays allows the numerical simulation of sloshing. It should be investigated, however, how accurate the results of this type of simulations are for this complex flow problem. The present paper first presents the details of a numerical model, an improved Volume OF Fluid (iVOF) method. Comparisons are made with sloshing model test results. Based on the results, the following conclusions can be drawn: - The dynamics of sloshing in LNG tanks can be simulated numerically using an iVOF Navier-Stokes solver. - Several improvements have been made in the treatment of numerical spikes in the pressure signals, but still more improvements need to be made. - Qualitatively, the pressure pulses resulting from impacts against the LNG tank wall show a rather good agreement between experiment and numerical simulation. - Quantitatively, the differences with the experiment show that further detailed studies with respect to cell sizes and time steps are necessary.
Siltation Calculation for Open Channel on the Silty Beach
Authors: Kong Lingshuang , Cao Zude , Li Yanbao , Zhang Mingxia , Ma Li
Published: January 2009

The characteristics of sediment movement on a silty beach are examined. A formula for the ratio of suspended sediment divided by bed load is derived by means of theoretical analysis and flume tests. Methods for siltation calculations for open channel on the silty beach are proposed.
Thermal Expansion by Lateral Buckling: Structural Reliability Analysis for the Penguins Flowline
Authors: Peek Ralf , Matheson Ian , Carr Malcolm , Saunders Paul , George Nigel
Published: January 2009

The Penguins pipeline is a 60 km PIP system designed to buckle laterally on the seabed. This is an effective way to accommodate thermal expansion. However excessive bending could lead to local buckling or wrinkling of the pipe wall. Existing design criteria based on load-controlled or displacement-controlled conditions are not directly applicable here, because the actual conditions fall somewhere in between. For this reason a structural reliability analysis has been performed for the Penguins flowline, to demonstrate that it is safe to allow the flowline to buckle laterally. Thereby the uncertainties that can affect the peak bending moments and curvatures at the buckles are addressed explicitly i.e. one does not rely on an assumption of load- or displacement control. This paper describes how describes how the various uncertainties are combined to assess the structural reliability. Details of the various inputs, including full-scale tests and finite element analyses addressing both global response and local buckling or wrinkling to develop the capacity and response functions are reported in a companion paper.
Weld Residual Stresses and Their Treatment in Fracture and Fatigue Assessment
Authors: Dong P.
Published: January 2009

Over the last decade, as more in-depth understanding of weld residual stresses is being achieved, particularly of their characteristic distributions in pressure vessel and piping components, the residual stress effects on stress intensities at welds are becoming better understood. In this paper, some of the important residual stress characteristics are first identified in the form of either “bending” dominated or “self-equilibrating” dominated types for girth welds. The applicability in other joint configurations in welded structures is then discussed, with a collection of validated residual stress distributions. The characterization of both “bending” and “self-equilibrating” types in residual stress distributions provides a consistent framework for stress intensity factor considerations in either fracture and fatigue assessment. The contribution of weld residual stresses to stress intensities at welds are shown to be in the form of K solutions under displacement controlled conditions. The “bending” type residual stresses provide a longer range of influence than “self-equilibrating” type in K solutions. The contribution of “self-equilibrating” type residual stresses to stress intensities is shown to be dominant when crack size is small, while the contribution of the “bending” type dominant for crack size up to a much large size with respect to wall thickness.
Freak Wave Events Within the Second Order Wave Model
Authors: Bitner-Gregersen Elzbieta M. , Hagen O̸istein
Published: January 2009

Recently significant interest has been paid to abnormal waves, often called rogue waves or freak waves. These waves represent operational risks to ship and offshore structures, and are likely to be responsible for a number of accidents. As shown by several authors, in ‘the second order world’ the freak waves are pretty rare events. The present study focuses on statistical properties of freak waves. The analyses are based on second order time domain simulations, short term distributions for crest statistics obtained from the literature, and long term field data. Time series of wave elevations are generated using the Pierson-Moskowitz, JONSWAP and two-peak Torsethaugen frequency spectrum for long-crested seas and deep water. Effects of combined seas (swell and wind sea) on wave statistics are discussed. Assuming 2nd order wave theory, the short term and long term probability of occurrence of a freak wave is estimated. The difference between a “freak wave” and a “dangerous wave” is pointed out. Finally, 100 year and 10000 year crest events obtained by analysis procedures used in the offshore industry are discussed in relation to freak waves.
Experience With Qualification and Use of Stainless Steels in Subsea Pipelines
Authors: Kvaale Per Egil , Ha˚brekke Tore , Ro̸rvik Gisle
Published: January 2009

Use of stainless steels in subsea oil and gas production systems have been common through the development of remote controlled subsea oil and gas production systems. Stainless steels are mainly selected to minimize the corrosion due to unprocessed oil and gas and thereby simplifying the internal corrosion protection challenges. Different materials and principles have been implemented from cladding of Carbon Manganese steels to the use of solid stainless steels. For cladding Incoloy 825 or Inconel 625 is common, while the solid stainless steels have been duplex, superduplex or 13%Cr steels in pipes and pipe fittings. Experience from service has shown that these materials have limits in their use, and it is reported various cases where the stainless steels have failed. The present paper will deal with a few examples of failures and possible reasons for these failures.
Solar Fired, Compressor Assisted Absorption Chillers
Authors: Bergquam James B. , Brezner Joseph M.
Published: January 2009

This paper presents the results of a thermodynamic and heat transfer analysis of solar fired, compressor assisted absorption chillers. The objectives are to determine and evaluate the feasibility of using vapor compressors to lower the operating temperature of the primary generator, simplify the maintenance and reduce the cost of solar/waste heat powered absorption HVAC systems. The nominal generator temperature in a single effect absorption chiller is 88°C and the coefficient of performance is approximately 0.8. A standard double effect chiller requires the high temperature generator to operate at about 150°C. The nominal COP of a double effect cycle is 1.2 to 1.4. Various modifications have been proposed to lower the operating temperature of the primary generator. One such modification is to add a vapor compressor to the basic cycle. Computer models that simulate the effect of vapor compressors at selected locations in single and double effect LiBr/H2O absorption chillers have been developed. Two locations were modeled for single effect chillers and three locations for double effect chillers. The best results were obtained for a double effect chiller with the compressor located between the high and low temperature generators.
Theoretical Analysis of Ammonia-Based Combined Power/Refrigeration Cycle at Low Refrigeration Temperatures
Authors: Lu Shaoguang , Goswami D. Yogi
Published: January 2009

A new combined power/refrigeration cycle uses ammonia/water mixture as a working fluid to produce both power and refrigeration in the same cycle. The cycle may be designed for various combinations of power and refrigeration. In an earlier paper by the authors, the cycle was optimized for efficiency, with power as the main intended output. This study puts an emphasis on the refrigeration part of the total output especially at low refrigeration temperatures. The objective was to find out what kind of outputs could be obtained at very low temperatures for a possible application in the Mars mission. The thermal performance of this cycle at different refrigeration temperatures has been found. At each refrigeration temperature, the cycle is optimized for maximum second law efficiency using Generalized Reduced Gradient (GRG) algorithm. It is found that refrigeration temperatures as low as 205 K may be achieved using this cycle. Generally, both first and second law efficiencies decrease when refrigeration temperature drops. For a re-circulating type of solar thermal system with a source temperature of 360K, the first and second law efficiencies increase slightly as the refrigeration temperature goes down from 265K to 245K and then decrease with the refrigeration temperature, giving a maximum second law efficiency of 63.7% at 245K.
Advanced Thermal Storage Fluids for Solar Parabolic Trough Systems
Authors: Moens Luc , Blake Daniel M. , Rudnicki Daniel L. , Hale Mary Jane
Published: January 2009

It has been established that the development of a storage option and increasing the operating temperature for parabolic trough electric systems can significantly reduce the levelized electricity cost (LEC) compared to the current state of the art. Both improvements require a new heat transfer fluid that must have a very low vapor pressure at the hot operating temperature and combined with a high thermal stability, higher than 450°C. Further, the piping layout of trough plants dictates that the fluid not be allowed to freeze, which dictates the use of extensive insulation and heat tracing unless the fluid has a freezing point near 0°C. At present, it seems likely that this “ideal” fluid will have to be found among organic rather than inorganic salts. We are therefore investigating the chemical and thermal properties of ‘room temperature ionic liquids’ (RTILs) that hold much promise as a new class of heat transfer or storage fluids.
Evaluation of a Molten Salt Heat Transfer Fluid in a Parabolic Trough Solar Field
Authors: Kearney D. , Herrmann U. , Nava P. , Kelly B. , Mahoney R. , Pacheco J. , Cable R. , Potrovitza N. , Blake D. , Price H.
Published: January 2009

An evaluation was carried out to investigate the feasibility of utilizing a molten salt as the heat transfer fluid (HTF) and for thermal storage in a parabolic trough solar field to improve system performance and to reduce the levelized electricity cost. The operating SEGS plants currently use a high temperature synthetic oil consisting of a eutectic mixture of biphenyl/diphenyl oxide. The scope of this investigation included examination of known critical issues, postulating solutions or possible approaches where potential problems existed, and the quantification of performance and electricity cost using preliminary, but reasonable, cost inputs. The two leading candidates were the so-called solar salt (a binary salt consisting of 60% NaNO3 and 40% KNO3) and a salt sold commercially as HitecXL (a ternary salt consisting of 48% Ca(NO3)2, 7% NaNO3, and 45% KNO3).
The Role of Surface Topography in MEMS Switches and Relays
Authors: Kogut L. , Komvopoulos K.
Published: January 2009

Microelectromechanical systems (MEMS) technology employed to generate switches and relays has the potential to replace traditional solid-state devices due to broader operating temperature range, higher breakdown voltage, and much higher off-state resistance. Interest in MEMS switches and relays has surged recently, principally due to the demonstrated performance in switching radio-frequency signals. The role of surface topography in the performance and lifetime of MEMS switches and relays is the objective of this review paper. Special emphasis is given to an approach that accounts for effect of roughness and to the role of surface topography in the pull-in voltage and contact bouncing. A critical assessment of emerging topics where experimental and theoretical studies are still required in order to obtain better insight into the role of surface topography in MEMS switches and relays is presented.
SEPARATION BETWEEN CLASSICAL AND QUANTUM WINNING STRATEGIES FOR THE MATCHING GAME
Authors: FIALÍK IVAN
Published: January 2009

Communication complexity is an area of classical computer science which studies how much communication is necessary to solve various distributed computational problems. Quantum information processing can be used to reduce the amount of communication required to carry out some distributed problems. We speak of pseudo-telepathy when it is able to completely eliminate the need for communication. The matching game is the newest member of the family of pseudo-telepathy games. After introducing a general model for pseudo-telepathy games, we focus on the question what the smallest size of inputs is for which the matching game is a pseudo-telepathy game.
LOCAL LIPSCHITZ REGULARITY OF MINIMA FOR A SCALAR PROBLEM OF THE CALCULUS OF VARIATIONS
Authors: MARICONDA CARLO , TREU GIULIA
Published: January 2009

We consider a functional I(u) = ∫Ωf(∇ u(x)) dx on u0 + W1,1(Ω). Under the assumption that f is just convex, we prove a new Comparison Principle, we improve and give a short proof of Cellina's Comparison result for a new class of minimizers. We then extend a local Lipschitz regularity result obtained recently by Clarke for a wider class of functions f and boundary data u0 satisfying a new one-sided Bounded Slope Condition. A relaxation result follows.
Body Composition, Abdominal Fat Distribution, and Prostate-Specific Antigen Test Results
Authors: Rundle Andrew , Richards Catherine , Neugut Alfred I.
Published: January 2009

Background: There are competing theories explaining the observed inverse association between obesity and screening prostate-specific antigen (PSA) levels: (a) endocrine disturbances related to abdominal obesity influence PSA production and (b) increased plasma volume associated with obesity dilutes PSA. Under the endocrine disturbance hypothesis, fat mass, but not lean mass, and an abdominal distribution of fat are expected to be inversely associated with PSA levels. Under plasma volume dilution theory, PSA levels are inversely associated with both lean and fat mass and are independent of body fat distribution patterns.

Methods: Data on weight, percent body fat measured by bioimpedance, and waist circumference from ∼8,000 men undergoing routine PSA screening were evaluated. Multivariate linear regression analyses controlling for age and race/ethnicity were used to determine whether fat, lean mass, or waist circumference were associated with PSA.

Results: PSA levels were significantly inversely associated with both lean and fat mass. In separate models, a 5-pound difference in lean mass and fat mass was associated, respectively with a −0.9% (P < 0.001) and −0.7% (P = 0.001) difference in PSA test results. In a model that simultaneously considered lean and fat mass, a 5-pound difference in lean mass and fat mass was associated, respectively, with a −0.6% (P = 0.03) and −0.4% (P = 0.08) difference in PSA test results. Controlling for body mass index, a 1-inch difference in waist circumference was associated with a +0.9% (P = 0.01) difference in PSA levels.

Conclusion: The results are more consistent with predictions arising from the volume dilution theory than the hormone disturbance theory. (Cancer Epidemiol Biomarkers Prev 2009;18(1):331–6)
Coexpression of α6β4 Integrin and Guanine Nucleotide Exchange Factor Net1 Identifies Node-Positive Breast Cancer Patients at High Risk for Distant Metastasis
Authors: Gilcrease Michael Z. , Kilpatrick Shannan K. , Woodward Wendy A. , Zhou Xiao , Nicolas Marlo M. , Corley Lynda J. , Fuller Gregory N. , Tucker Susan L. , Diaz Leslie K. , Buchholz Thomas A. , Frost Jeffrey A.
Published: January 2009

Preclinical data indicate that α6β4 integrin signaling through Ras homolog gene family, member A, plays an important role in tumor cell motility. The objective of this study was to determine whether the combined expression of α6β4 integrin and neuroepithelioma transforming gene 1 (Net1), a guanine nucleotide exchange factor specific for Ras homolog gene family member A, is associated with adverse clinical outcome in breast cancer patients. Immunohistochemical expression of each protein was evaluated in a tumor tissue microarray prepared from the primary tumors of 94 node-positive patients with invasive breast carcinoma treated with total mastectomy and doxorubicin-based chemotherapy without radiation with a median follow-up of 12.5 years. Associations between staining results and multiple clinicopathologic variables were investigated. Although there was no significant association between α6β4 integrin or Net1 expression and clinical outcome when each marker was considered individually, coexpression of α6β4 and Net1 was associated with decreased distant metastasis–free survival (P = 0.030). In the subset of patients with hormone receptor–positive tumors, coexpression of α6β4 and Net1 was associated with a decrease in distant metastasis–free and overall survival (P < 0.001 and P = 0.006, respectively). Although an association between human epidermal growth factor receptor 2 expression and coexpression of α6β4 and Net1 (P = 0.008) was observed, coexpression of α6β4 and Net1 (hazard ratio, 1.63; P = 0.02) and lymphovascular invasion (hazard ratio, 2.35; P = 0.02) were the only factors independently associated with the development of distant metastasis in multivariate analysis. These findings suggest that coexpression of α6β4 integrin and Net1 could be a useful biomarker for aggressive disease in node-positive breast cancer patients. (Cancer Epidemiol Biomarkers Prev 2009;18(1):80–6)
Growth Inhibition and Regression of Lung Tumors by Silibinin: Modulation of Angiogenesis by Macrophage-Associated Cytokines and Nuclear Factor-κB and Signal Transducers and Activators of Transcription 3
Authors: Tyagi Alpna , Singh Rana P. , Ramasamy Kumaraguruparan , Raina Komal , Redente Elizabeth F. , Dwyer-Nield Lori D. , Radcliffe Richard A. , Malkinson Alvin M. , Agarwal Rajesh
Published: January 2009

The latency period for lung tumor progression offers a window of opportunity for therapeutic intervention. Herein, we studied the effect of oral silibinin (742 mg/kg body weight, 5 d/wk for 10 weeks) on the growth and progression of established lung adenocarcinomas in A/J mice. Silibinin strongly decreased both tumor number and tumor size, an antitumor effect that correlates with reduced antiangiogenic activity. Silibinin reduced microvessel size (50%, P < 0.01) with no change in the number of tumor microvessels and reduced (by 30%, P < 0.05) the formation of nestin-positive microvessels in tumors. Analysis of several proteins involved in new blood vessel formation showed that silibinin decreased the tumor expression of interleukin-13 (47%) and tumor necrosis factor-α (47%), and increased tissue inhibitor of metalloproteinase-1 (2-fold) and tissue inhibitor of metalloproteinase-2 (7-fold) expression, without significant changes in vascular endothelial growth factor levels. Hypoxia- inducible factor-1α expression and nuclear localization were also decreased by silibinin treatment. Cytokines secreted by tumor cells and tumor-associated macrophages regulate angiogenesis by activating nuclear factor-κB (NF-κB) and signal transducers and activators of transcription (STAT). Silibinin decreased the phosphorylation of p65NF-κB (ser276, 38%; P < 0.01) and STAT-3 (ser727, 16%; P < 0.01) in tumor cells and decreased the lung macrophage population. Angiopoietin-2 (Ang-2) and Ang-receptor tyrosine kinase (Tie-2) expression were increased by silibinin. Therapeutic efficacy of silibinin in lung tumor growth inhibition and regression by antiangiogenic mechanisms seem to be mediated by decreased tumor-associated macrophages and cytokines, inhibition of hypoxia-inducible factor-1α, NF-κB, and STAT-3 activation, and up-regulation of the angiogenic inhibitors, Ang-2 and Tie-2.
Variation in Platelet Function Testing Has a Major Influence on Detection of Aspirin Resistance in Healthy Subjects
Authors: Božič-Mijovski Mojca , Rakuša Matej , Stegnar Mojca
Published: January 2009

Introduction: An increased demand for monitoring aspirin treatment by platelet function tests has been observed, but data on the biological variation of these tests are insufficient. The aim of this study was to assess the biological variation of optical platelet aggregometry and closure time in healthy subjects without aspirin and after aspirin ingestion. Subjects and Methods: In 20 healthy subjects, blood was sampled 4 times: on 2 consecutive mornings a day after aspirin ingestion (100 mg/daily) and on 2 consecutive days of no treatment. In all samples, arachidonic acid-, ADP- and collagen-induced optical platelet aggregation was measured, and closure times were determined by collagen/epinephrine (CEPI) and collagen/ADP (CADP) cartridges in a platelet function analyzer-100. Results: Aspirin significantly reduced arachidonic acid- and ADP-induced platelet aggregation and significantly prolonged CEPI closure time, but had no significant effect on collagen-induced platelet aggregation and CADP closure time. Aspirin increased both within- and between-subject coefficients of variation. Arachidonic acid-induced platelet aggregation was the most sensitive to aspirin and no aspirin-resistant subjects were detected on either day after aspirin. According to ADP-induced platelet aggregation or CEPI closure time, 25 and 30% of healthy subjects, respectively, changed from aspirin resistant to aspirin responsive or vice versa from one day to another. There was no agreement between platelet function tests in determining aspirin resistance. Conclusions: A significant variation in optical platelet aggregometry and closure time exists and is presumed to have a major effect on determination of aspirin resistance.
Transient Ventriculomegaly in an Adolescent Presenting with Shunted Hydrocephalus, Diabetic Ketoacidosis, and Hyperglycemia
Authors: Gruber Thomas J. , Rozzelle Curtis J.
Published: January 2009

In this report, the authors describe a unique presentation ofventriculomegaly in the setting of diabetic ketoacidosis (DKA). A 15-year-old male, with a history of shunt placement for hydrocephalus and repair of a myelomeningocele, presented to the emergency room with DKA and was found to have ventriculomegaly. At the time of presentation, the patient had a 24- to 48-hour history of lethargy, nausea, vomiting, fever (102.2 °F), and polydipsia. A computed tomographic (CT) scan of the head indicated increased ventricular size compared with previous studies, thus prompting a neurosurgical evaluation. Blood glucose level at admission was found to be 1,551 mg/dl, bicarbonate level was 9 mmol/l, and pH was 7.08. The patient was treated for DKA; his fever, lethargy, nausea, and vomiting subsequently resolved. A repeat CT scan obtained 24 h after admission revealed a return of the ventricular system to its baseline size. On the basis of radiographic and laboratory evaluations, the authors hypothesize that the transient ventriculomegaly was directly related to extreme hyperglycemia.
Acute Painless Shoulder Weakness during High-Intensity Athletic Training
Authors: Vachon LT Tyler , Rosenthal Michael , Dewing Christopher B. , Solomon Daniel J. , Shin Alexander Y. , Provencher Matthew T.
Published: January 2009

Background

High-intensity repetitive athletic activities may predispose the brachial plexus to repetitive stretch, compression, and subsequent injury, although painless shoulder weakness is a rare event.

Purpose

The physical examination and electrodiagnostic findings in a series of United States Navy special warfare trainees who presented with acute painless shoulder weakness are presented, along with subsequent treatment and return-to-duty timeline.

Study Design

Case series; Level of evidence, 4.

Methods

From August 2005 to August 2006, a total of 11 of 212 (5%) Navy Basic Underwater Demolition School trainees were identified with acute onset (<3 weeks) painless shoulder weakness without any prior shoulder injury. In all shoulders, symptoms began during a telephone pole lift-carry drill. All trainees underwent serial examinations, electrodiagnostic testing, and a comprehensive rehabilitation program.

Results

Physical examination revealed universal weakness in flexion and abduction and electrodiagnostic studies confirmed injury to the C5-6 area of the brachial plexus (axillary, suprascapular, and musculocutaneous). All 11 patients were removed from training and started on a physical therapy program until functional recovery at a mean of 21 weeks after onset of symptoms (range, 12-24). All 11 resumed military activities; however, only 6 completed the Navy Basic Underwater Demolition School program.

Conclusion

In physically intense training or athletic environments, injuries to the upper brachial plexus may present with various forms of upper extremity dysfunction, including painless shoulder weakness. This information provides insight into a potentially debilitating shoulder problem and offers guidance on future training principles.
Employee Families and Organizations as Mutually Enacted Environments
Authors: Golden Annis G.
Published: January 2009

Work—life research tends to privilege the organization—employee relationship, with the family's role largely relegated to providing emotional and material support to the employee and adapting to organizational requirements. Systems oriented research, however, points toward a larger role for the family, including mediating the employee's relationship with the organization as well as direct organizational interactions. This study uses Weick's model of organizational sensemaking to examine, through the analysis of employee and family interview accounts, how a global high-tech organization and its employees' families enact one another as environments. Three dynamics of mutual enactments— two cooperative and one competitive—were identified, along with implications for work—life integration research and practice, for more traditionally programmatic work—life accommodations, and for families' management of their relationships to employing organizations.
Effects of Contamination of Biobased Hydraulic Fluids with Mineral Oil
Authors: Theissen Heinrich W.
Published: January 2009

There are many occasions for biobased hydraulic fluids to be contaminated with mineral oil, caused either by incomplete flushing during conversion from mineral oil to bio-oil, or by carelessness during maintenance and refilling. With high contamination levels, problems like foaming, poor air release, or filter clogging have been reported. In experiments at IFAS (Institute for Fluid Power Drives and Controls) of RWTH Aachen University, relevant properties of biobased oils contaminated with different levels of various mineral oils have been analyzed. It was found, that the degree of deterioration correlates not to the amount of mineral oil added, but to the amount of metals introduced through the mineral oil’s additives. Deterioration effects may take several hours or days to develop. The effects are specific for different bio-oil products. As a practical consequence, some changes in quality control, product documentation, and standardization are recommended.
Decreased Mortality of Lake Michigan Chinook Salmon after Bacterial Kidney Disease Challenge: Evidence for Pathogen Driven Selection?
Authors: Purcell Maureen K. , Murray Anthony L. , Elz Anna , Park Linda K. , Marcquenski Susan V. , Winton James R. , Alcorn Stewart W. , Pascho Ronald J. , Elliott Diane G.
Published: January 2009

In the late 1960s, Chinook salmon Oncorhynchus tshawytscha from the Green River, Washington, were successfully introduced into Lake Michigan. During spring from1988 to 1992, large fish die offs affecting Chinook salmon occurred in the lake. Multiple ecological factors probably contributed to the severity of the fish kills, but the only disease agent found regularly was Renibacterium salmoninarum, the causative agent of bacterial kidney disease. In this study, survival after challenge by R. salmoninarum was compared between two Chinook salmon stocks: a Lake Michigan stock from Wisconsin (WI) and the progenitor stock from the Green River. We found that the WI stock had significantly greater survival than the Green River stock. Next, the WI and Green River stocks were exposed to the marine pathogen Listonella anguillarum (formerly Vibrio anguillarum), one of the causative agents of vibriosis; survival after this challenge was significantly poorer for the WI stock than for the Green River stock. A close genetic relationship between the Green River and WI stocks was confirmed by analyzing 13 microsatellite loci. These results collectively suggest that disease susceptibility of Lake Michigan Chinook salmon has diverged from that of the source population, possibly in response to pathogen driven selection.
A Model of the Effects of Flow Fluctuations on Fall Chinook Salmon Spawning Habitat Availability in the Columbia River
Authors: Geist David R. , Murray Christopher J. , Hanrahan Timothy P. , Xie Yulong
Published: January 2009

The logistic regression models that we previously used to predict where fall Chinook salmon Oncorhynchus tshawytscha would spawn in the Hanford Reach of the Columbia River were based on so-called static variables (i.e., the riverbed surface substrate, riverbed slope, and time-averaged velocity and depth [representing the velocity and depth in each cell associated with the 50% exceedance flow]). Not all habitat predicted to be used for spawning contained redds, and one explanation for the overprediction is that the models did not incorporate streamflow fluctuation. Streamflow fluctuation occurs daily in the Hanford Reach owing to load-following operations (power generation to meet short-term electrical demand) at Priest Rapids Dam, a hydroelectric dam located at the upper end of the reach. Daily flow fluctuations could change the hydraulic characteristics to which fall Chinook salmon respond in selecting redd sites. The purpose of this study was to determine whether incorporating metrics of flow variability would improve modeling of spawning habitat availability. Flow variability was represented by so-called dynamic variables (i.e., the standard deviations of velocity and depth for each habitat cell over a 60-d time segment during the fall spawning period in 1994, 1995, and 2001). Both the static and dynamic models were correct at least 85% of the time in predicting habitat as spawning or nonspawning. However, incorporation of the dynamic variables into the logistic regression models reduced the amount of overpredicted habitat by 42% in 1994, 32% in 1995, and 25% in 2001. For example, the area predicted to be suitable but not used in 1994 decreased from 20.8 ha for the static model to 12.1 ha for the dynamic model for all sites combined; similar results were found for 1995 and 2001. This represents an improvement in our ability to accurately predict suitable fall Chinook salmon spawning habitat in the Hanford Reach of the Columbia River.
Ranking Predatory Threats by Nonnative Fishes in the Yampa River, Colorado, via Bioenergetics Modeling
Authors: Johnson Brett M. , Martinez Patrick J. , Hawkins John A. , Bestgen Kevin R.
Published: January 2009

Because of its relatively natural hydrograph, the Yampa River, Colorado, is considered the crown jewel of native fish habitat in the upper basin of the Colorado River and has supported a relatively intact native fish assemblage. Nonnative fishes are thought to pose the greatest threat to native fishes in this system. Removal programs for nonnative northern pike Esox lucius and channel catfish Ictalurus punctatus have highlighted managers' perception of the threat posed by each species. Recent expansion of nonnative smallmouth bass Micropterus dolomieu in the Yampa River attracted an avid angling clientele but also coincided with a precipitous decline in native fishes, necessitating a rigorous assessment of the relative impact of all three nonnative predators on the native fishes. We used abundance, growth, and diet estimates for each predator species to quantify consumptive demand using bioenergetics models. Despite a low abundance of small-bodied fishes and thus a low number of fish in the smallmouth bass diet, total fish consumption by smallmouth bass (mean = 15.2 kg·km−1·year−1; 95% confidence interval [CI] = 13.3–17.1 kg·km−1·year−1) was similar to that estimated for northern pike (mean = 13.7 kg·km−1·year−1, 95% CI = 11.4–16.0 kg·km−1·year−1) and was about 65 times higher than the estimate for channel catfish (mean = 0.22 kg·km−1·year−1; 95% CI = 0.05–0.40 kg·km−1·year−1). Diet data from the upper Colorado River, where small-bodied fish were plentiful, suggested that piscivory by smallmouth bass in the Yampa River could be 10 times the piscivory by northern pike and channel catfish, or about 168.5 kg·km−1·year−1 (95% CI = 147.0–189.9 kg·km−1·year−1), if prey fish were more available. This level of piscivory suggested that smallmouth bass presented the greatest predatory threat to native fishes of the Yampa River. As environmental conditions change, use of field monitoring together with bioenergetics modeling will be an effective framework to assist managers in adapting their nonnative fish control efforts to maximize the likelihood of native fish recovery.
Surface Area Estimates of Streams and Rivers Occupied by Nonnative Fish and Amphibians in the Western USA
Authors: Whittier Thomas R. , Peck David V.
Published: January 2009

Statistically robust, broad-scale measures of the portion of an aquatic resource (e.g., a stream and river network) occupied by nonnative fish and amphibian species should be useful to resource managers but with a few exceptions have not been available. We used data from the western stream and river survey of the U.S. Environmental Protection Agency's Environmental Monitoring and Assessment Program to estimate the surface area of flowing waters occupied by nonnative fish and amphibian species at three spatial scales. For the 12-state survey area, an estimated 75% of the surface area of the target stream network had one or more nonnative fish or amphibian species, compared with 52% of the stream length. At all spatial scales (except the state of Washington), the estimates of the proportion of surface area with nonnatives were larger than those for estimated stream length. The relative extent of occupancy for individual species often differed depending on how they were assessed. For example, when assessed by length of network occupied, brook trout Salvelinus fontinalis was the most widespread nonnative fish (17%) but dropped to ninth position when assessed by surface area occupied (7%), while common carp Cyprinus carpio went from fourth position (10% of stream length) to second position when assessed by surface area occupied (27%). Estimates of the surface areas of flowing waters occupied by nonnative species are useful and easily calculated additions to the ways in which probability-based surveys can assess the condition of the resource.
Aminopyralid and Clopyralid Absorption and Translocation in Canada Thistle (Cirsium arvense)
Authors: Bukun Bekir , Gaines Todd A. , Nissen Scott J. , Westra Philip , Brunk Galen , Shaner Dale L. , Sleugh Byron B. , Peterson Vanelle F.
Published: January 2009

Aminopyralid is a new auxinic herbicide that provides Canada thistle control at lower use rates than clopyralid. Studies were conducted to determine if differences in absorption, translocation, or metabolism account for aminopyralid's greater biological activity. Radiolabeled aminopyralid and clopyralid were applied to individual leaves of rosette-stage Canada thistle plants. Nonionic surfactant was used for the absorption studies because it provided higher aminopyralid absorption than methylated seed oil or crop oil concentrate. Clopyralid was absorbed very rapidly, reaching 72% 24 h after treatment (HAT) and remaining near or above 80% during a 192-h time course. During the same time period, aminopyralid absorption increased from 34 to 60%. Clopyralid translocation out of the treated leaf was significantly higher than aminopyralid, 39% compared with 17%, respectively, 192 HAT. More of applied clopyralid translocated to aboveground tissue 192 HAT (27%) than to roots (12%), whereas aminopyralid translocation was similar in aboveground tissue (10%) and roots (7%) 192 HAT. Neither aminopyralid nor clopyralid was metabolized 192 HAT. Although aminopyralid is effective at lower use rates than clopyralid, clopyralid absorption and translocation were higher in Canada thistle. These results suggest that aminopyralid's chemical structure may provide for greater biological activity at the target site than clopyralid.
Wedelia trilobata (l.) A.S. Hitchc. (Asteraceae) - A new record for Bangladesh
Authors: Hossain ABM Enayet , Hassan Md Abul
Published: January 2009

Not available. Key words: Wedelia trilobata (L.) A.S. Hitchc.; Asteraceae; new record; Bangladesh DOI: 10.3329/bjpt.v12i1.612 Bangladesh J. Plant Taxon. 12(1): 63-65, 2005 (June)
Additions to the genus Stigeoclonium (Chlorophyta) as new records for Bangladesh
Authors: Khan Mazibar Rahman , Islam AKM Nurul
Published: January 2009

Three taxa belonging to the genus Stigeoclonium (Chaetophorales, Chlorophyta) are described here as new records for Bangladesh, namely, Stigeoclonium amoenum var. novizelandicum, S. protensum and S. tenue var. uniforme. Key words: New records, Stigeoclonium, Chlorophyta, Chaetophoraceae, Bangladesh DOI: 10.3329/bjpt.v12i2.598 Bangladesh J. Plant Taxon. 12(2): 1-9, 2005 (December)
Pleurocarpous mosses of Bangladesh : Symphyodontaceae and Amblystegiaceae
Authors: Khatun Hamida , Hadiuzzaman Syed
Published: January 2009

A taxonomic account of six species of Pleurocarpous mosses of Bangladesh of the families Symphyodontaceae and Amblystegiaceae under the order Hookeriales and Hypnobryales respectively are given. Key words: Pleurocarpous moss, Hookeriales, Hypnobryales, Symphyodontaceae, Amblystegiaceae, Bangladesh DOI: 10.3329/bjpt.v13i1.591 Bangladesh J. Plant Taxon. 13(1): 29-40, 2006 (June)
Aquatic flora in two Indian ponds near Kolkata, West Bengal: Implications for conservation
Authors: Mukhopadhyay Gautam , Sengupta Sourav , Dewanji Anjana
Published: January 2009

Occurrence, coverage and chemical constituents of aquatic flora were studied in two Indian ponds over a period of 39-month in order to gain an insight into their associations and infestation for implications in conservation and management. Species diversity was recorded in presence of two invasive species (Alternanthera philoxeroides (Martius) Griseb. and Lemna aequinoctialis Welwitsch). These species should be managed in view of their beneficial uses. Nymphaea pubescens Willd, a threatened species, was recorded. Positive association of Nymphoides hydrophylla (Loureiro) O. Kuntze with Alternanthera philoxeroides and Vallisneria spiralis L. showed that spatially separated habitats are useful for conservation. Azolla pinnata R. Brown, an useful species and Rotala rotundifolia (F. Hamilton ex Roxburgh) Koehne, an uncommon species, were able to produce high coverage in their brief occurrence - important for their conservation. Similar feature as observed in Cladophora glomerata (L.) Kütz and Hydrodictyon reticulatum (L.) Lagerh. is useful for management of these species due to their negative impacts. Key words: Aquatic flora, Species composition, Occurrence, Coverage, Nitrogen, Phosphorus, Management DOI: 10.3329/bjpt.v14i1.519 Bangladesh J. Plant Taxon. 14(1): 13-24, 2007 (June)
The genus Pronephrium C. Presl (Thelypteridaceae) from Bangladesh
Authors: Mirza Momtaz Mahal
Published: January 2009

The paper deals with the genus Pronephrium C. Presl of the family Thelypteridaceae and includes five species, namely P. articulatum (Haulst. & Moore) Holtt., P. lakhimpurensis (Rosenst.) Holtt., P. nudatum (Roxb. ex Griff.) Holtt., P. parishii (Bedd.) Holtt., and P. triphyllum (Sw.) Holtt. from Bangladesh. Descriptions of the species with artificial key, illustrations, distribution and short notes with conservation measures are given here. Key words: Pronephrium, Thelypteridaceae, Pteridophyte, Bangladesh DOI: 10.3329/bjpt.v14i1.521 Bangladesh J. Plant Taxon. 14(1): 37-45, 2007 (June)