bluuebunny/crossref_metadata_2025 huggingface dataset:
ASSOCIATED INHERITANCE OF REACTION TO RACES OF CROWN RUST, PUCCINIA CORONATA AVENAE ERIKSS., AND TO VICTORIA BLIGHT, HELMINTHOSPORIUM VICTORIAE M. AND M., IN OATS
Authors: Welsh J. N. , Peturson B. , Machacek J. E.
Published: May 2008

The oat variety Victoria has been shown by various investigators to be resistant to most races of crown rust but susceptible to a disease known as Victoria blight. This disease was observed for the first time in the United States in 1944 and in Canada in 1947. Susceptibility to this disease has been considered, by several workers, to be linked with the Victoria type of resistance to crown rust. The present investigations indicate that Victoria has more than one major gene for resistance to crown rust. These findings are based on data from a study of advanced generation selections of Victoria parentage and from inheritance studies involving varieties with the Victoria resistance to crown rust, such as Garry and R.L. 1987. Lines were obtained from Garry and from F3 populations of different crosses with the following three types of disease reactions: (1) lines susceptible to Victoria blight and resistant to all crown rust races studied, namely, races 1, 2, 3, 4, 5, 6, 24, 34, 34A. 38, 45, and 57; (2) lines resistant to Victoria blight and susceptible to crown rust races 4, 5, 34A, and 57, but resistant to the other races; (3) lines resistant to Victoria blight and susceptible to all races. Inheritance studies of three crosses, Garry × Exeter, Garry × Roxton, and Roxton × R.L. 1987, indicate that susceptibility to Victoria blight is dominant and governed by a single major gene; that resistance to races 4, 5, 34A, and 57 of crown rust is dominant and governed by a single major gene, but linked with susceptibility to Victoria blight; and that resistance to race 45, as well as races 1, 2, 3, 6. 24, 34, and 38, which appear to be similar to race 45 in inheritance, is conditioned by three dominant genes, one of which is associated, with susceptibility to Victoria blight.
YELLOW LAMINATED ROOT ROT OF DOUGLAS FIR
Authors: Buckland D. C. , Molnar A. C. , Wallis G. W.
Published: May 2008

Yellow laminated root rot occurs in most native conifers throughout the range of Douglas fir in British Columbia. The cause of this disease has been ascribed to a variety of Poria weirii Murr., or a species of Poria distinct from P. weirii. The fungus grows from infected to healthy roots through physiologically weakened contacting points or fusions, and the disease is most prevalent in Douglas fir because of the common occurrence of root fusion in this species. Douglas fir is susceptible at any age over six years but individual trees show marked differences in their resistance to killing by the disease. The symptom picture varies greatly between infected trees and is directly related to the resistance shown by the individual host. Inoculum may remain viable for over 50 years in stumps and roots. The fungus does not appear to spread through the soil nor does it appear to be able to penetrate healthy bark tissue. Although the control of this disease is currently important in many localized areas, several characteristics in the behavior of the causal fungus indicate that it will become more important as management of second growth Douglas fir forests becomes more intensive.
STUDIES ON SWEET CLOVER FAILURES IN SOUTHWESTERN ONTARIO
Authors: Benedict W. G.
Published: May 2008

The etiology of sweet clover failures that have occurred in recent years in southwestern Ontario was investigated further through studies of the possible role of adverse environmental factors, of insects, and of pathogenic bacteria and fungi. A number of soil-borne parasites were found. They exhibited unusual parasitism at the point of initial infection and as the disease occurred in the field. Phytophthora cactorum was found to cause the disease, and its parasitism of sweet clover was investigated. The susceptibility of the host varied sharply with its stage of development and was at a minimum in the seedling stage and greatest early in the second season's growth. Numerous lenticels on the tap roots provided natural breaks in the periderm through which the fungus probably entered. Invasion of the tissue by the fungus was intracellular in the relatively small number of instances when first season plants were attacked and was always intercellular when second season plants were attacked. The fungus sporulated when seedlings were infected and when extracts of seedlings were added to common artificial media. Mycelium of the fungus was found abundant in cortical parenchyma considerably in advance of lesions. Secondary organisms quickly followed the initial infection. Epidemiological studies of sweet clover failures indicated that outbreaks were characterized by relatively short periods of high disease incidence in the early part of the second growing season in individual clover stands. An analysis of weather data for the period during which recent epidemics occurred suggested that sustained high soil moisture in the early part of the growing season was prerequisite to epidemic outbreaks of the disease, with higher than average soil temperatures favorable as well. No phonological condition, however, seemed responsible for confining the outbreaks to the beginning of the second season of growth, which appeared to be incidental to some physiological change correlated with the developmental rhythm of the host.
STUDIES IN FOREST PATHOLOGY: XIII. DECAY IN SUGAR MAPLE IN THE OTTAWA–HURON AND ALGOMA EXTENSION FOREST REGION OF ONTARIO
Authors: Nordin Vidar J.
Published: May 2008

Decay results in appreciable losses in sound wood volume in sugar maple (Acer saccharum, Marsh.) timber in the Ottawa–Huron and Algoma Extension Forest region of Ontario. Seventy-four per cent of 606 sample trees had some measure of decay. Twenty-eight fungi were found to be associated with decay in living trees. The most important of these are Armillaria mellea (Vahl ex Fr.) Quél., Polyporus glomeratus Peck, Ustulina vulgaris Tub, Fomes connatus (Weinm.) Gill., Hydnum septentrionale Fr., Corticium vellereum Ell. & Crag., Pholiota spectabilis Fr., and Fomes igniarius (L. ex. Fr.) Gill. Several species previously unreported in the literature were found to be associated with decay in sugar maple in Ontario. Armillaria mellea is the most serious butt-decay fungus and P. glomeratus is the most important trunk-rotting species. Frost cracks are the most important courts of entry for decay fungi. Various discolorations occur in sugar maple. The average extent of decay in living trees is estimated according to the occurrence of sporophores of F. connatus, F. igniarius, H. septentrionale, and U. vulgaris. The incidence and volume of decay increased progressively with age and diameter. One hundred and nine species of Basidiomycetes are tabulated as occurring on living and dead sugar maple in Ontario.
CELLULAR DEDIFFERENTIATION AND REDIFFERENTIATION IN SPLACHNUM AMPULLACEUM (L.) HEDW.
Authors: MacNutt Mary M. , Maltzahn K. E. Von
Published: May 2008

Cellular dedifferentiation and redifferentiation are studied in leaves of the moss gametophore. Changes in the size and number of some cellular constituents as well as changes in their position are observed. Cell division, the plane of new wall formation, and factors affecting them are considered. Isolation of the leaf initiates events leading to the dedifferentiated state of the component cells. These changes include increase in the size of the nucleus and nucleolus and decrease in the size of the chloroplasts accompanied by an increase in chloroplast numbers. Changes in the position of cellular components are initiated by intravacuolar cytoplasmic layer formation leading to systrophe. Systrophe is considered to be an important event in dedifferentiation representing the final topography of the cellular constituents in the dedifferentiated cell. The distribution of clusters is observed, indicating loss of cellular polarity. In order for redifferentiation to take place, a new axis of polarity must be initiated. Redifferentiation leads ultimately to cell division. This division is characterized and the distribution of planes of new wall formation is shown.
THE INDUCTION OF APOGAMY IN THE BRACKEN FERN
Authors: Whittier Dean P. , Steeves Taylor A.
Published: May 2008

A new method of inducing apogamy in normal fern gametophytes of Pteridium aquilinum has been demonstrated. Entire plants, apparently isolated sporophytic members, and structures of an intermediate nature between sporophyte and gametophyte were produced. The method involved growing gametophytes in sterile culture on a nutrient medium containing a suitable concentration of glucose. A series of experiments was carried out in which the concentration of glucose was varied from 0–8% and the optimum concentration was established to be 2.5%. Prothalli grown in the absence of glucose, which have only their photosynthate as an energy source, produced no apogamous structures. It was found that sucrose, maltose, or fructose could be substituted for the glucose in the induction of apogamy. Four other strains of Pteridium, and strains of Osmunda cinnamomea and Adiantum pedatum, also responded to the sugar treatment by producing apogamous plants. The osmotic pressure of the medium has been shown to have no effect on the induction of apogamy but it does appear to cause the decline in the response at the higher concentrations of sugar. The role of the sugar would therefore seem to be as a respiratory substrate, which in some way favors the induction of apogamy.
ADDITIONAL DIAPORTHALES ON TWIGS FROM ONTARIO
Authors: Reid James , Cain R. F.
Published: May 2008

The following fungi are newly reported from Ontario: Cryptosporella paucispora (Pk.) Berl. & Vogl., Diaporthe taleola (Fr.) Sacc., Diaporthe leiphaemia var. raveneliana (De Thüm. & Rehm) Wehm., Apioporthe anomala (Pk.) Höhn., and Valsa salicis (Fuckel) Winter.The status of the family Cryptosporellaceae sensu von Arx and Müller is briefly discussed.
IDENTIFICATION OF CULTURES OF WOOD-INHABITING HYMENOMYCETES
Authors: Nobles Mildred K.
Published: May 2008

A multiple-choice key for the identification of cultures of 149 species of wood-inhabiting Hymenomycetes, whose cultural characters have been published previously, is based on the following diagnostic characters: presence or absence of extracellular oxidase, types of septation of hyphae, occurrence of special structures and accessory spores, color of hyphae and mycelial mats, color changes in agar, rates of growth, formation of fruit bodies, odor, host relationships, and interfertility phenomena. In the key, each diagnostic character is symbolized by a number, the Code Symbol; each species is described in abbreviated form by a Species Code, the series of Code Symbols that denote the characters shown by the species; and each section in the key is headed by its Key Code, the series of Code Symbols that denote the characters shared by all the species in the section. Most of the final sections in the key consist of a number of species with identical or similar Species Codes. In these sections, detailed descriptions of the cultural characters of the species have been inserted.
Analysis of snow avalanche terrain
Authors: Schaerer P. A.
Published: May 2008

A multiple regression analysis has been performed of the average annual number of avalanches and terrain factors. Observations were made at 36 paths at Rogers Pass over a period of 9 years. The average slope inclination measured from the starting point to the beginning of the run-out zone and exposure to wind proved to be the most significant variables. Slope angle at the starting point, variations over the track, and roughness of the ground surface were of secondary significance and their influence varied strongly from site to site. The analysis confirmed that avalanches need either a steep slope or a snow drift to start and a mimimum inclination of track to maintain their motion.
The prediction of total heave of a slab-on-grade floor on Regina clay
Authors: Yoshida R. T. , Fredlund D. G. , Hamilton J. J.
Published: May 2008

Several analytical methods for the prediction of total heave of desiccated, expansive soils have been proposed for various geographic regions. The proposed method herein is based on a general theory for unsaturated soil. The in situ stress conditions, as assessed from the corrected swelling pressure and the required soil moduli, are deduced from the constant volume oedometer test.Verification of the proposed method was accomplished using data accumulated from the monitoring of movements of a floor slab in a light industrial building in north-central Regina, Saskatchewan. A leak in a water line buried under the floor slab resulted in a maximum heave of about 106 mm. Of the three final pore-water pressure distributions assumed, the one where pressure is constant with depth and equal to atmospheric pressure appears to be representative of the field conditions corresponding to the maximum measured heave. The measured heave represents 89% of the predicted heave for the zero pore-water pressure distribution. It is concluded that the proposed method of analysis, based upon a general theory for unsaturated soils, provides a practical method to accurately assess total heave.
On the nature of the minimum creep rate – time correlation for soil, ice, and frozen soil
Authors: Ting John M.
Published: May 2008

This technical note examines the nature and consequences of the linear correlation observed between the logarithm of the minimum creep rate, [Formula: see text] and the logarithm of the time to reach this minimum creep rate, tm, in soil, ice, and frozen soil. Simple mathematical creep models show that this correlation is due to the existence of an approximately constant strain at the minimum strain rate, and the relative insensitivity of the double logarithmic plot to small deviations from this approximately constant strain. Keywords: creep, failure, frozen soil, ice, unfrozen soil.
Modulus of elasticity of a very dense glacial till determined by plate load tests
Authors: Fisher William R.
Published: May 2008

The modulus of elasticity of a very dense glacial till deposit located in central Maine has been determined by in situ plate load tests. The results of these tests are presented and the values of modulus of elasticity evaluated.
Behaviour of a test excavation in soft Champlain Sea clay
Authors: Lafleur J. , Silvestri V. , Asselin R. , Soulié M.
Published: May 2008

The field observations made during a sloped excavation in a soft sensitive clay are presented. The test site is located in Saint-Hilaire, in a typical Champlain Sea clay deposit, of 30 m depth. The trench was 8 m deep and 60 × 60 m square and its slopes were at 45, 34, 27, and 18° to the horizontal. The induced pore pressures and total lateral stresses have been recorded with vibrating-wire instruments since the beginning of the excavation. The steepest, 45° slope completely failed 1 day after excavating and the 34° slope, 2 weeks after. The piezometer readings have shown that the groundwater regime was modified proportionally to the changes in total stresses; these modifications took place within a time period of 5 months, after which the heads became more or less constant. The total stress cells indicated significant rotation of the principal axes at the toe of the slopes. Stability analyses using the lowest vane strength profile gave minimum factors of safety of 1.15 for the 45° slope and 1.23 for the 34° slope, thereby underestimating the risks of failure. Back analyses using regional effective shear strength parameters were made and the parameters mobilized at failure were found to be [Formula: see text] and [Formula: see text]. Key words: case record, excavation, soft clay, slope stability, back analysis.
First R. M. Hardy Memorial Lecture: Fracture lineament research and applications on the western Canadian plains
Authors: Mollard J. D.
Published: May 2008

For parts of the western Canadian plains, high-altitude airphotos and satellite images frequently show a simple pattern of preferred fracture lineament orientations. Fracture lineaments are composite linear topographic, drainage, vegetation, moisture, and tonal features. A long search for their origin and repeating characteristics is described. It is held that certain elements of fracture lineament networks are selectively inherited from preexisting regional fracture systems and structures in the underlying rocks, and can therefore be correlated with subsurface geological, hydrogeological, and geophysical and near-surface geochemical data. A number of case studies illustrate how remotely sensed lineament data are applied in geological, hydrogeological, and geotechnical investigations for resource exploration, development, and management. Key words: remote sensing, fracture lineaments, propagation, hierarchy, domain, stress field, salt tectonics, data correlation, application.
Viscosity, yield stress, remolded strength, and liquidity index relationships for sensitive clays
Authors: Locat Jacques , Demers Denis
Published: May 2008

The rheological behavior of some sensitive clays has shown that there are positive relationships between plastic viscosity, yield stress, remolded shear strength, and liquidity index. Based on the various correlations, remolded strength values can be predicted for soils with a liquidity index as high as 6. For a liquidity index varying from 2 to 5, the remolded undrained shear strength and plastic viscosity vary from about 90 to 5 Pa and from 200 to 7 mPa∙s respectively. It has been observed that most sensitive clays behave either as a Bingham or a Casson fluid, the latter behavior being related to less sensitive clays of higher pore-water salinities. Increasing the salt content from 0.5 to 30 g/L modified the rheological behavior of a single test soil from that of a Bingham to that of a Casson type of fluid. Such modification in the pore-water salinity illustrates how soils can have similar plastic viscosity and similar remolded strength but different yield stresses. The range of viscosity measured for sensitive clays is very different from that of values obtained from back analysis of subaerial or submarine slides where viscous flow can be expected. Key words: sensitivity, clays, viscosity, yield stress, shear strength, salinity, liquidity index, submarine slide, landslide.
Preconsolidation pressures in intertill glaciolacustrine clay near Blaine Lake, Saskatchewan
Authors: Sauer E. Karl , Christiansen E. A.
Published: May 2008

Soft, intertill, glaciolacustrine clays are of concern for stability of slopes and foundations. An intertill clay deposit between 32 and 54 m below the surface was continuously cored. Index properties were determined for 46 samples and 10 samples were tested on the oedometer. Stratigraphic evidence indicates that the glaciolacustrine clay (Blaine Lake Member), lying between the till of the Sutherland and Saskatoon groups, was glaciated three times. However, preconsolidation pressures of this intertill clay show the degree of consolidation is less than 20% based on a total stress from an estimated ice thickness extrapolated from the Cypress Hills. This low preconsolidation pressure suggests there was insufficient time for dissipation of excess pore-water pressure created by thickening of the advancing glacier. Key words: preconsolidation pressure, excess pore-water pressure, glaciers, intertill clay.
Enzymatic processes for biodegradation of poly(hydroxyalkanoate)s crystals
Authors: Numata Keiji , Abe Hideki , Doi Yoshiharu
Published: May 2008

Poly(hydroxyalkanoate)s (PHAs) have attracted much attention as environmentally compatible polymeric materials that can be produced from renewable carbon resources. Biodegradation of PHA materials occurs by the function of extracellular PHA depolymerase secreted from microorganisms. Thus, elucidation of the enzymatic degradation mechanism for PHA materials is important to design PHA materials with desirable properties and controlled biodegradability. The solid PHA polymer is a water-insoluble substrate but PHA depolymerases are soluble in water. Therefore, the enzymatic degradation of PHA materials is a heterogeneous reaction on the material’s surface. Two distinct processes are involved during the degradation, namely, adsorption of the enzyme on the surface of PHA material and the subsequent hydrolysis of polymer chains. Atomic force microscopy (AFM) is a powerful tool that has been used for the quantitative analysis of PHA crystal degradation. AFM enables the characterization of the crystal surface nanostructure in a buffer solution. By using in-situ (real-time) AFM observations, we recently succeeded in observing the degradation processes of PHA crystals. Subsequently, we were also able to investigate the degradation rates of PHA crystals using the same technique. In this review, we have attempted to give an overview concerning the direct visualization of the adsorption, as well as the hydrolysis reactions of PHA depolymerases at the nanometer scale. In addition, we present other analytical techniques besides AFM as a complimentary approach to analyze the effect of enzyme adsorption on PHA crystals.Key words: poly(hydroxyalkanoate) (PHA), enzymatic degradation, lamellar crystal, PHA depolymerase.
Mixed-dimer formation in binary systems of 4-substituted benzoic acids and structure considerations
Authors: Roman Maren , Kaeding-Koppers Annett , Zugenmaier Peter
Published: May 2008

The phase behavior of binary systems of 4-substituted benzoic acids is governed by the formation of mixed dimers. This study was conducted to determine the effect of the components’ structural difference on mixed-dimer formation in crystalline and liquid-crystalline phases. The phase diagrams of two systems, with 4-[(S)-(–)-2-methylbutoxy]benzoic acid (MBOBA) as one component and 4-(hex-5-enoxy)benzoic acid (HOBA) and 4-(dec-9-enoxy)benzoic acid (DOBA), respectively, as the second component, were determined by differential scanning calorimetry, polarized-light microscopy, and X-ray diffraction. The MBOBA-HOBA system exhibited a cholesteric phase, two solid solutions, and above 58 °C for compositions between 40 and 80 mol% HOBA a crystalline phase of mixed dimers. The MBOBA-DOBA system showed a crystalline phase of mixed dimers at all compositions, a cholesteric phase, and a twisted smectic C phase, which was dominated by mixed dimers at 60 and 70 mol% DOBA. We conclude that liquid-crystalline phases are generally dominated by mixed dimers, but in crystalline phases the formation of mixed dimers is promoted by a greater difference in molecular structure. The crystal structure of two of the pure compounds MBOBA and DOBA and comparable compounds have been determined for an evaluation of the arrangements of the molecules in the crystal and liquid-crystalline state.Key words: benzoic acid, crystal arrangement, phase diagrams, liquid crystal.
Preparation and Photoluminescent Properties of new Europium Complexes with 2'-Hydroxy- 3-(p- methoxyphenyl) Propiophenone
Authors: Kumar Rajesh , Makrandi J. K. , Taxak Vinod B. , Khatkar Satyender P.
Published: May 2008

The study of the coordination compounds of the trivalent rare earth ions continues to be an active research area, which may attributed to the luminescent properties of these compounds and their application as optical signal amplifier, electroluminescent devices and luminescent probes in biological system. The new complex Eu(HMPP)3.2H20 (where HMPP=2'-Hydroxy-3-(p-methoxyphenyl)propiophenone was synthesized and characterized by I.R.spectroscopy, TGA/DTA and elemental analysis. The qualitative analysis of the complex to detect the presence of europium has been performed by energy dispersive analysis (EDAX). The synthesized complex on exposure to U.V. light at 354nm emits red luminescence with main peak at 618nm. The complex emitting bright red colour might be promisingly applicable for optical devices, solid state lamps for general illumination purposes, optical signal amplifier, electroluminescent devices and luminescent probes in biological system. Keywords: - Photoluminescence, europium complex, I.R, elemental analysis, EDAX.
Localized Lattice Parameter Measurements in LixCoO2 Particles by Transmission Electron Microscopy
Authors: Gabrisch Heike , Xing Qingfeng , Yi Tanghong
Published: May 2008

The correlation between lithium content and lattice parameter in LixCoO2 is commonly measured by x-ray diffraction resulting in reliable information averaged over a large specimen volume. In the present work Convergent Beam Electron Diffraction in a transmission electron microscope is used to obtain diffraction information from small specimen volumes within single LixCoO2 particles. Our results indicate that LixCoO2 particles subjected to the same oxidizing treatment show a distribution of lattice parameters that includes differences between single particles and within different regions of the same LixCoO2 particle. Systematic CBED measurements on delithiated particles have the potential to provide valuable information for the simulation of the electrochemical behavior of LiCoO2 cathodes.
Characterization and Electrochemical Performance of Substituted LiNi0.4Co0.2-yAlyMn0.4O2 (0{less than or equal to}y{less than or equal to}0.2) Cathode Materials
Authors: Wilcox James , Doeff Marca
Published: May 2008

A complete series of LiNi0.4Co0.2-yAlyMn0.4O2 (0{less than or equal to}y{less than or equal to}0.2) materials have been synthesized and investigated as cathode materials for lithium ion batteries. When cycled between 2.0 and 4.3 V vs. Li/Li+ at a current density of 0.1 mA/cm2, stable capacities of ~160 mAh/g for y=0 to ~110 mAh/g for y=0.2 are achieved. Upon increasing the current density, it is found that all materials containing aluminum show reduced polarization and improved rate performance. The optimal performance at all current densities was found for the compound with y=0.05. The effect of aluminum substitution on the crystal structure of the host is discussed.
The Application of Pulse Charge for Secondary Lithium Battery
Authors: Lin Chuang-Yaw , Yen Shi-Chern
Published: May 2008

The pulse current (PC) charging has less concentration over-potential, internal resistance, and side-reactions compared to those of constant current (CC) charging. In this study, the charging and discharging capacities of LiMn2O4 battery were investigated using the battery performance tester by pulse current charge. The average of C-rate is introduced to indicate the effects of the three variables, pulse-on time, pulse-off time, and the applied C-rate. From the experimental results, it can be found that pulse charging is helpful to reduce capacity loss and gives the batteries higher discharge capacity. The optimal operating conditions can be represented by the average of C-rate, and also derived from the percentage of capacity loss.
Polyacrylate as Modifier for Graphite/Electrolyte Interface
Authors: Komaba Shinichi , Okushi Koji , Groult Henri
Published: May 2008

Polyacrylate anion was used as binder of graphite electrode in lithium-ion cell to modify the interface. Compared with polyvinylidene fluoride, the coulombic efficiency at the initial cycle was improved by polyacrylic acid and alkali polyacrylates in an ethylene carbonate (EC) based electrolyte. Although the polyvinylidene fluoride electrode showed a huge irreversible capacity in propylene carbonate (PC) electrolyte, the polyacrylate modified graphite demonstrated highly reversible lithium intercalation in a PC electrolyte as well as in an EC based electrolyte.
The Use of Electrolyte Additives to Improve the High Temperature Resilience of Li-Ion Cells
Authors: Smart M. C. , Lucht Brett L. , Ratnakumar B. V.
Published: May 2008

As part of our continuing efforts to develop advanced electrolytes to improve the performance of lithium-ion cells, especially over wide temperature ranges, we have investigated a number of electrolyte additives, which were incorporated into multi-component electrolyte formulations with the intent of improveing the high temperature resilience. In the present work, we have investigated two Lewis base electrolyte additives developed at URI (1), namely dimethyl acetamide (DMAC) and N-methyl pyrrolidinone (NMP), which have been compared with other previously reported additives (i.e., vinylene carbonate, VC, and vinyl ethylene carbonate, VEC). These Lewis base stabilizing agents have been found to reversibly bind with PF5, preventing LiPF6 and carbonate solvents from undergoing decomposition at high temperature. These additives have been incorporated into a previously developed electrolyte consisting of LiPF6 dissolved in a ternary mixture of carbonates (2). It was determined that cells containing the electrolytes with the additives far outperformed the baseline solution with respect to the extent of capacity retention observed when subjected to high temperatures, with DMAc and VC yielding the best results
Electrolytes Containing Fluorinated Ester Co-Solvents for Low-Temperature Li-Ion Cells
Authors: Smith Kiah A. , Smart M. C. , Prakash G. K. Surya , Ratnakumar B. V.
Published: May 2008

The fluorinated esters 2,2,2-trifluoroethyl butyrate (TFEB), 2,2,2-trifluoroethyl acetate (TFEA), ethyl trifluoroacetate (ETFA), and methyl pentafluoropropionate (MPFP) are added to carbonate-based electrolyte solvents in varying amounts to improve the low temperature performance and high temperature resiliency of lithium-ion cells. These fluorinated ester co-solvents are also anticipated to improve the safety characteristics, film forming properties and physical properties. Reported within this paper are results on the electrochemical characterization and charge/discharge characteristics of MCMB-LiNixCo1-xO2 the cells that contain various fluorinated ester-containing electrolytes. Results obtained showed that the cell containing the electrolyte consisting of 1.0 M LiPF6 in 20:60:20 v/v% ethylene carbonate (EC)/ethyl, methyl carbonate (EMC)/ TFEB had the best performance of all the fluorinated ester containing mixtures investigated in nearly all tests, and also performed comparably to the baseline carbonate only mixtures.
Implementation and Effect of Stabilized Lithium Metal Powder on Mesocarbon Negative Electrodes
Authors: Cassel Frank , Chua David , Lane Melissa , Yakovleva Marina , Gao Yaun , Au George
Published: May 2008

Techniques for implementing stabilized lithium metal powder (Lectro® Max Powder 150, SLMPTM) as a surface application onto mesocarbon cathodes have been studied. These techniques included dip coating, draw-down coating and spray coating already prepared electrodes in a dry room environment. This testing resulted in electrodes that demonstrated a reduced apparent loss, which has the potential to improve the overall capacity of commercial cells. Of these three techniques, spray coating was determined to be the most applicable method of depositing the SLMPTM onto the coating with appropriate precision. More specifically, a low volume, low pressure off-the-shelf sprayer with a standard modification to replace the PTFE seals with polyethylene seals could be used to spray the coating to the proper loading. With proper mixing techniques, large numbers of electrodes could be sprayed with one batch of SLMPTM slurry, allowing eventually for larger prismatic lithium ion cells to be developed.
An Investigation of Blade Failures in Combustion Turbines
Authors: Caldwell Mia , Viswanathan Ramaswami
Published: May 2008

Cracked and uncracked second row blades of 50 MW class combustion turbines have been studied to identify the cause of failure. Results show that the failures have been caused by environmentally-assisted creep in a manner similar to stress corrosion. A window of grain boundary spikes, indicative of the corresponding stress variation was observed locally at the failure site. A superimposition of the ranges of stress and those of corrosion seems to create the conditions under which creep and grain boundary corrosion can occur concurrently in a synergistic manner. Results show that operation at different rating, the types of corrosion found in the blades remain unchanged, but the magnitude and the location at which the different corrosion features are observed are changed systematically.
High Temperature Corrosion of Materials in Supercritical Water and Liquid Lead-Alloy Environments
Authors: Sridharan Kumar , Chen Yun , Tan Lizhen , Machut McLean Terrence , Kruizenga Alan , Ren Xiaowei , Allen Todd R.
Published: May 2008

The Supercritical Water-cooled Reactor (SCWR) and Lead-cooled Fast Reactor (LFR) are among the six reactor concepts identified by the Generation IV initiative for the next generation nuclear reactors. Materials degradation due to corrosion is a significant issue in both supercritical water and molten lead (-alloy) environments, particularly at the intended higher temperatures of application. In supercritical water, corrosion of ferritic and austenitic steels and Inconel alloys occurs mainly by the growth of an oxide layer on the surface. In molten lead (-alloy), corrosion can occur by dissolution of the material, oxidation, or by the penetration of liquid metal into the material primarily along the grain boundaries. Surface treatment of ferritic steels by the incorporation of thin film of oxidation-resistant materials has been shown to mitigate corrosion in these aggressive environments. Grain boundary engineering (GBE) reduces spallation of oxide layers in austenitic steels in supercritical water environment.
Interfacial Resistivity of Yttria Stabilized Zirconia in Operating Solid Oxide Fuel Cells
Authors: Pomfret Michael B. , Eigenbrodt Bryan C. , Walker Robert
Published: May 2008

Electrochemical impedance spectroscopy (EIS) has been used to characterize the lateral impedance across the surface of polycrystalline yttria stabilized zirconia (YSZ) electrolytes in functioning solid oxide fuel cells (SOFCs). Experiments varied the applied overpotential of an electrolyte supported, membrane electrode assembly (MEA) operating with (dry) H2 at 775åC and then measured the impedance between two conducting element located on the anode surface. The conducting elements consisted of either porous Au or a porous Ni/YSZ cermet and the distance between elements varied between 0.5 mm and 1.0 mm. Reduced YSZ surfaces (at OCV) showed lower lateral impedance compared to the lateral impedance of a polarized cell. The largest polarization resistances were measured for SOFCs operating steady state at higher cell potentials. Making several assumptions about the extent to which YSZ is reduced by molecular H2, one can estimate a lateral YSZ resistivity of ~10-3-10-4 Ω•cm.
The Protonation Behavior of Metal Oxide Surfaces to Hydrothermal Conditions
Authors: Machesky Michael L. , Wesolowski D. J. , Ridley Moira K. , Palmer Donald A. , Rosenqvist Jorgen , Lvov Serguei , Fedkin Mark , Predota Milan , Vlcek Lukas
Published: May 2008

Metal oxide surface protonation under hydrothermal conditions is summarized. Important concepts and definitions are introduced first, followed by a brief overview of experimental methods and presentation of representative results. Finally, the modeling methods that are most useful in predicting surface protonation behavior between 0 and 300oC are presented and compared.
Hepatic uptake and metabolism of galactose can be quantified in vivo by 2-[18F]fluoro-2-deoxygalactose positron emission tomography
Authors: Sørensen Michael , Munk Ole Lajord , Mortensen Frank Viborg , Olsen Aage Kristian , Bender Dirk , Bass Ludvik , Keiding Susanne
Published: May 2008

Metabolism of galactose is a specialized liver function. The purpose of this PET study was to use the galactose analog 2-[18F]fluoro-2-deoxygalactose (FDGal) to investigate hepatic uptake and metabolism of galactose in vivo. FDGal kinetics was studied in 10 anesthetized pigs at blood concentrations of nonradioactive galactose yielding approximately first-order kinetics (tracer only; n = 4), intermediate kinetics (0.5–0.6 mmol galactose/l blood; n = 2), and near-saturation kinetics (>3 mmol galactose/l blood; n = 4). All animals underwent liver C15O PET (blood volume) and FDGal PET (galactose kinetics) with arterial and portal venous blood sampling. Flow rates in the hepatic artery and the portal vein were measured by ultrasound transit-time flowmeters. The hepatic uptake and net metabolic clearance of FDGal were quantified by nonlinear and linear regression analyses. The initial extraction fraction of FDGal from blood-to-hepatocyte was unity in all pigs. Hepatic net metabolic clearance of FDGal, KFDGal, was 332–481 ml blood·min−1·l−1 tissue in experiments with approximately first-order kinetics and 15.2–21.8 ml blood·min−1·l−1 tissue in experiments with near-saturation kinetics. Maximal hepatic removal rates of galactose were on average 600 μmol·min−1·l−1 tissue (range 412–702), which was in agreement with other studies. There was no significant difference between KFDGal calculated with use of the dual tracer input (KdualFDGal) or the single arterial input (KarterialFDGal). In conclusion, hepatic galactose kinetics can be quantified with the galactose analog FDGal. At near-saturated kinetics, the maximal hepatic removal rate of galactose can be calculated from the net metabolic clearance of FDGal and the blood concentration of galactose.
Modulation of mouse intestinal epithelial cell turnover in the absence of angiotensin converting enzyme
Authors: Haxhija Emir Q. , Yang Hua , Spencer Ariel U. , Koga Hiroyuki , Sun Xiaoyi , Teitelbaum Daniel H.
Published: May 2008

Angiotensin converting enzyme (ACE) has been shown to be involved in regulation of apoptosis in nonintestinal tissues. This study examined the role of ACE in the modulation of intestinal adaptation utilizing ACE knockout mice (ACE−/−). A 60% small bowel resection (SBR) was used, since this model results in a significant increase in intestinal epithelial cell (EC) apoptosis as well as proliferation. Baseline villus height, crypt depth, and intestinal EC proliferation were higher, and EC apoptosis rates were lower in ACE−/−compared with ACE+/+mice. After SBR, EC apoptosis rates remained significantly lower in ACE−/−compared with ACE+/+mice. Furthermore, villus height and crypt depth after SBR continued to be higher in ACE−/−mice. The finding of a lower bax-to-bcl-2 protein ratio in ACE−/−mice may account for reduced EC apoptotic rates after SBR in ACE−/−compared with ACE+/+mice. The baseline higher rate of EC proliferation in ACE−/−compared with ACE+/+mice may be due to an increase in the expression of several EC growth factor receptors. In conclusion, ACE appears to have an important role in the modulation of intestinal EC apoptosis and proliferation and suggests that the presence of ACE in the intestinal epithelium has a critical role in guiding epithelial cell adaptive response.
Effects of isoproterenol treatment for 7 days on inflammatory mediators in the rat aorta
Authors: Davel Ana Paula C. , Fukuda Livia E. , De Sá Larissa Lima , Munhoz Carolina D. , Scavone Cristoforo , Sanz-Rosa David , Cachofeiro Victoria , Lahera Vicente , Rossoni Luciana V.
Published: May 2008

The aim of the present study was to evaluate the effect of overstimulation of β-adrenoceptors on vascular inflammatory mediators. Wistar rats were treated with the β-adrenoceptor agonist isoproterenol (0.3 mg·kg−1·day−1 sc) or vehicle (control) for 7 days. At the end of treatment, the right carotid artery was catheterized for arterial and left ventricular (LV) hemodynamic evaluation. Isoproterenol treatment increased LV weight but did not change hemodynamic parameters. Aortic mRNA and protein expression were quantified by real-time RT-PCR and Western blot analysis, respectively. Isoproterenol enhanced aortic mRNA and protein expression of IL-1β (124% and 125%) and IL-6 (231% and 40%) compared with controls but did not change TNF-α expression. The nuclear-to-cytoplasmatic protein expression ration of the NF-κB p65 subunit was increased by isoproterenol treatment (51%); in addition, it reduced the cytoplasmatic expression of IκB-α (52%) in aortas. An electrophoretic mobility shift assay was performed using the aorta, and increased NF-κB DNA binding (31%) was observed in isoproterenol-treated rats compared with controls ( P < 0.05). Isoproterenol treatment increased phenylephrine-induced contraction in aortic rigs ( P < 0.05), which was significantly reduced by superoxide dismutase (150 U/ml) and sodium salicylate (5 mM). Cotreatment with thalidomide (150 mg·kg−1·day−1 for 7 days) also reduced hyperreactivity to phenylephrine induced by isoproterenol. In conclusion, overstimulation of β-adrenoceptors increased proinflammatory cytokines and upregulated NF-κB in the rat aorta. Moreover, local oxidative stress and the proinflammatory state seem to play key roles in the altered vascular reactivity of the rat aorta induced by chronic β-adrenergic stimulation.
TTF-1 response element is critical for temporal and spatial regulation and necessary for hormonal regulation of humansurfactant protein-A2promoter activity
Authors: Liu Dongyuan , Yi Ming , Smith Margaret , Mendelson Carole R.
Published: May 2008

Expression of the human surfactant protein-A2 ( hSP-A2) gene is lung specific, occurs in type II and Clara cells, and is developmentally and hormonally regulated in fetal lung. Using transfected human fetal type II cells, we previously observed that ∼300 bp of 5′-flanking DNA mediated cAMP and interleukin-1 (IL-1) stimulation and dexamethasone (Dex) inhibition of hSP-A2 promoter activity. This region contains response elements for estrogen-related receptor α element (ERRE, −241 bp), thyroid transcription factor (TTF)-1/Nkx2.1 (TTF-binding protein, −171 bp), upstream stimulatory factor 1/2 (E-box, −80 bp), and stimulatory protein (Sp) 1 (G/T-box, −62 bp), which are essential for basal and cAMP induction of hSP-A2 expression. To define genomic regions necessary for developmental, hormonal, and tissue-specific regulation of hSP-A2 expression in vivo, we analyzed transgenic mice carrying hGH reporter genes comprised of 313 bp of hSP-A2 gene 5′-flanking DNA ± mutation in the TBE or 175 bp of 5′-flanking DNA, containing TBE, E-box and G/T-box, but lacking ERRE. Transgenes containing 313 or 175 bp of hSP-A2 5′-flanking DNA were expressed in a lung cell-specific manner and developmentally regulated in concert with the endogenous mouse SP-A gene. In cultured lung explants from hSP-A− 313:hGH transgenic fetal mice, cAMP and IL-1 induced and Dex inhibited transgene expression. However, the 175-bp hSP-A2 genomic region was insufficient to mediate hormonal regulation of hSP-A2 promoter activity. The finding that expression of the hSP-A− 313TBEmut:hGH transgene was essentially undetectable in fetal lung and was not hormonally regulated in transgenic fetal lung explants underscores the critical importance of the TBE in lung cell-specific, developmental, and hormonal regulation of hSP-A2 gene expression.
Human cardiorespiratory and cerebrovascular function during severe passive hyperthermia: effects of mild hypohydration
Authors: Fan Jui-Lin , Cotter James D. , Lucas Rebekah A. I. , Thomas Kate , Wilson Luke , Ainslie Philip N.
Published: May 2008

The influence of severe passive heat stress and hypohydration (Hypo) on cardiorespiratory and cerebrovascular function is not known. We hypothesized that 1) heating-induced hypocapnia and peripheral redistribution of cardiac output (Q̇) would compromise blood flow velocity in the middle cerebral artery (MCAv) and cerebral oxygenation; 2) Hypo would exacerbate the hyperthermic-induced hypocapnia, further decreasing MCAv; and 3) heating would reduce MCAv-CO2 reactivity, thereby altering ventilation. Ten men, resting supine in a water-perfused suit, underwent progressive hyperthermia [0.5°C increments in core (esophageal) temperature (TC) to +2°C] while euhydrated (Euh) or Hypo by 1.5% body mass (attained previous evening). Time-control (i.e., non-heat stressed) data were obtained on six of these subjects. Cerebral oxygenation (near-infrared spectroscopy), MCAv, end-tidal carbon dioxide (PetCO2) and arterial blood pressure, Q̇ (flow model), and brachial and carotid blood flows (CCA) were measured continuously each 0.5°C change in TC. At each level, hypercapnia was achieved through 3-min administrations of 5% CO2, and hypocapnia was achieved with controlled hyperventilation. At baseline in Hypo, heart rate, MCAv and CCA were elevated ( P < 0.05 vs. Euh). MCAv-CO2 reactivity was unchanged in both groups at all TC levels. Independent of hydration, hyperthermic-induced hyperventilation caused a severe drop in PetCO2 (−8 ± 1 mmHg/°C), which was related to lower MCAv (−15 ± 3%/°C; R2 = 0.98; P < 0.001). Elevations in Q̇ were related to increases in brachial blood flow ( R2 = 0.65; P < 0.01) and reductions in MCAv ( R2 = 0.70; P < 0.01), reflecting peripheral distribution of Q̇. Cerebral oxygenation was maintained, presumably via enhanced O2-extraction or regional differences in cerebral perfusion.
Effects of cardiotonic steroids on dermal collagen synthesis and wound healing
Authors: El-Okdi Nasser , Smaili Sleiman , Raju Vanamala , Shidyak Amjad , Gupta Shalini , Fedorova Larisa , Elkareh Jihad , Periyasamy Sankaridrug , Shapiro Anna P. , Kahaleh M. Bashar , Malhotra Deepak , Xie Zijian , Chin Khew Voon , Shapiro Joseph I.
Published: May 2008

We previously reported that cardiotonic steroids stimulate collagen synthesis by cardiac fibroblasts in a process that involves signaling through the Na-K-ATPase pathway (Elkareh et al. Hypertension 49: 215–224, 2007). In this study, we examined the effect of cardiotonic steroids on dermal fibroblasts collagen synthesis and on wound healing. Increased collagen expression by human dermal fibroblasts was noted in response to the cardiotonic steroid marinobufagenin in a dose- and time-dependent fashion. An eightfold increase in collagen synthesis was noted when cells were exposed to 10 nM marinobufagenin for 24 h ( P < 0.01). Similar increases in proline incorporation were seen following treatment with digoxin, ouabain, and marinobufagenin (10 nM × 24 h, all results P < 0.01 vs. control). The coadministration of the Src inhibitor PP2 or N-acetylcysteine completely prevented collagen stimulation by marinobufagenin. Next, we examined the effect of digoxin, ouabain, and marinobufagenin on the rate of wound closure in an in vitro model where human dermal fibroblasts cultures were wounded with a pipette tip and monitored by digital microscopy. Finally, we administered digoxin in an in vivo wound healing model. Olive oil was chosen as the digoxin carrier because of a favorable partition coefficient observed for labeled digoxin with saline. This application significantly accelerated in vivo wound healing in rats wounded with an 8-mm biopsy cut. Increased collagen accumulation was noted 9 days after wounding (both P < 0.01). The data suggest that cardiotonic steroids induce increases in collagen synthesis by dermal fibroblasts, as could potentially be exploited to accelerate wound healing.