bluuebunny/crossref_metadata_2025 huggingface dataset:
Antibody expressing pea seeds as fodder for prevention of gastrointestinal parasitic infections in chickens
Authors: Zimmermann Jana , Saalbach Isolde , Jahn Doreen , Giersberg Martin , Haehnel Sigrun , Wedel Julia , Macek Jeanette , Zoufal Karen , Glünder Gerhard , Falkenburg Dieter , Kipriyanov Sergey M
Published: September 2009

Background

Coccidiosis caused by protozoans of genusEimeriais a chicken parasitic disease of great economical importance. Conventional disease control strategies depend on vaccination and prophylactic use of anticoccidial drugs. Alternative solution to prevent and treat coccidiosis could be provided by passive immunization using orally delivered neutralizing antibodies. We investigated the possibility to mitigate the parasitic infection by feeding poultry with antibody expressing transgenic crop seeds.

Results

Using the phage display antibody library, we generated a panel of anti-EimeriascFv antibody fragments with high sporozoite-neutralizing activity. These antibodies were expressed either transiently in agrobacteria-infiltrated tobacco leaves or stably in seeds of transgenic pea plants. Comparison of the scFv antibodies purified either from tobacco leaves or from the pea seeds demonstrated no difference in their antigen-binding activity and molecular form compositions. Force-feeding experiments demonstrated that oral delivery of flour prepared from the transgenic pea seeds had higher parasite neutralizing activityin vivothan the purified antibody fragments isolated from tobacco. The pea seed content was found to protect antibodies against degradation by gastrointestinal proteases (>100-fold gain in stability).Ad libitumfeeding of chickens demonstrated that the transgenic seeds were well consumed and not shunned. Furthermore, feeding poultry with shred prepared from the antibody expressing pea seeds led to significant mitigation of infection caused both by high and low challenge doses ofEimeriaoocysts.

Conclusion

The results suggest that our strategy offers a general approach to control parasitic infections in production animals using cost-effective antibody expression in crop seeds affordable for the animal health market.
Functional consequences of structural differences in stingray sensory systems. Part I: mechanosensory lateral line canals
Authors: Jordan Laura K. , Kajiura Stephen M. , Gordon Malcolm S.
Published: September 2009

Short range hydrodynamic and electrosensory signals are important during final stages of prey capture in elasmobranchs (sharks, skates and rays), and may be particularly useful for dorso-ventrally flattened batoids with mouths hidden from their eyes. In stingrays, both the lateral line canal and electrosensory systems are highly modified and complex with significant differences on ventral surfaces that relate to feeding ecology. This study tests functional hypotheses based on quantified differences in sensory system morphology of three stingray species, Urobatis halleri, Myliobatis californica and Pteroplatytrygon violacea. Part I investigates the mechanosensory lateral line canal system whereas part II focuses on the electrosensory system. Stingray lateral line canals include both pored and non-pored sections and differ in branching complexity and distribution. A greater proportion of pored canals and high pore numbers were predicted to correspond to increased response to water flow. Behavioral experiments were performed to compare responses of stingrays to weak water jets mimicking signals produced by potential prey at velocities of 10–20 cm s–1. Bat rays, M. californica, have the most complex and broadly distributed pored canal network and demonstrated both the highest response rate and greater response intensity to water jet signals. Results suggest that U. halleri and P. violacea may rely on additional sensory input, including tactile and visual cues, respectively, to initiate stronger feeding responses. These results suggest that stingray lateral line canal morphology can indicate detection capabilities through responsiveness to weak water jets.
Functional consequences of structural differences in stingray sensory systems. Part II: electrosensory system
Authors: Jordan Laura K. , Kajiura Stephen M. , Gordon Malcolm S.
Published: September 2009

Elasmobranch fishes (sharks, skates and rays) possess highly sensitive electrosensory systems, which enable them to detect weak electric fields such as those produced by potential prey organisms. Different species have unique electrosensory pore numbers, densities and distributions. Functional differences in detection capabilities resulting from these structural differences are largely unknown. Stingrays and other batoid fishes have eyes positioned on the opposite side of the body from the mouth. Furthermore, they often feed on buried prey, which can be located non-visually using the electrosensory system. In the present study we test functional predictions based on structural differences in three stingray species (Urobatis halleri, Pteroplatytrygon violacea and Myliobatis californica)with differing electrosensory system morphology. We compare detection capabilities based upon behavioral responses to dipole electric signals(5.3–9.6 μA). Species with greater ventral pore numbers and densities were predicted to demonstrate enhanced electrosensory capabilities. Electric field intensities at orientation were similar among these species, although they differed in response type and orientation pathway. Minimum voltage gradients eliciting feeding responses were well below 1 nVcm–1 for all species regardless of pore number and density.
Navigational abilities of adult and experienced homing pigeons deprived of olfactory or trigeminally mediated magnetic information
Authors: Gagliardo Anna , Ioalè Paolo , Savini Maria , Wild Martin
Published: September 2009

Anatomical evidence and conditioning experiments have suggested that magnetoreceptors innervated by the ophthalmic branch of the trigeminal nerve are located in the upper beak of homing pigeons. Following these findings it has been proposed that the trigeminally-mediated magnetorececeptors are able to detect magnetic field intensity, which might be useful for a position finding mechanism for pigeons homing from unfamiliar locations. Recent data have shown that, in inexperienced pigeons, section of the ophthalmic branch of the trigeminal nerve does not impair navigational abilities. Similarly, no impairment was observed if the trigeminal section was performed on young pigeons, before they have had the opportunity to learn a navigational map. By contrast, section of the olfactory nerve either in adult inexperienced pigeons or in young birds before map learning, disrupted their homing performance. Nevertheless, because a magnetic map mechanism requires training flights for learning the magnetic gradient of the territory around the loft, the question remains as to whether the navigational performance of adult experienced pigeons can be affected by lack of magnetic information. To answer this question we extensively group-trained adult pigeons and then surgically deprived them of either olfactory or trigeminally mediated magnetic information, prior to testing their navigational abilities. The birds deprived of trigeminally mediated magnetic information displayed similar navigational abilities as intact control pigeons, whereas the olfactory-deprived pigeons were dramatically impaired in homing. Our data show that even in trained adult pigeons, olfactory cues are needed for homing from unfamiliar locations and that the lack of magnetic information does not affect navigational abilities of experienced adult homing pigeons.
Endocrine mechanisms mediating temperature-induced reproductive behavior in red-sided garter snakes (Thamnophis sirtalis parietalis)
Authors: Lutterschmidt Deborah I. , Mason Robert T.
Published: September 2009

We investigated the mechanisms by which temperature induces seasonal reproductive behavior in red-sided garter snakes (Thamnophis sirtalis parietalis). Specifically, we addressed whether elevated temperatures during winter dormancy influence (1) diel melatonin and corticosterone rhythms; (2) sex steroid hormone and corticosterone profiles; and (3) the expression of reproductive behavior following emergence. Elevated hibernation temperatures (i.e. 10°C versus 5°C) significantly increased overall melatonin and decreased corticosterone concentrations of snakes. The temperature-induced differences in melatonin rhythms between the 5°C and 10°C treatment groups persisted even after both groups were again acclimated to 10°C, indicating that cold temperature exposure has a lasting influence on melatonin rhythms. Elevated hibernation temperatures also significantly altered androgen and corticosterone profiles of snakes,providing a potential mechanism to explain reported annual variation in steroid hormones. Although previous studies indicate that male red-sided garter snakes exhibit a dissociated reproductive strategy, we demonstrate the presence of intersexual variation in sex steroid hormone profiles, as estradiol concentrations of female snakes increased significantly prior to spring mating activity. Importantly, the percentage change in body mass did not differ significantly between snakes in the hibernation treatments,indicating that the observed changes in hormone profiles are indeed temperature induced and not simply an indirect result of significant changes in the energy balance of snakes. Finally, in males maintained at 10°C during winter dormancy the onset of courtship behavior following emergence was delayed. Our results suggest that environmental temperatures induce reproductive behavior, in part, via changes in diel melatonin and/or corticosterone rhythms in this seasonally breeding reptile.
Functional differences between two CRF-related diuretic hormone receptors in Drosophila
Authors: Hector Clare E. , Bretz Colin A. , Zhao Yan , Johnson Erik C.
Published: September 2009

In Drosophila, two related G-protein-coupled receptors are members of the corticotropin releasing factor (CRF) receptor subfamily. We have previously reported that one of these receptors, encoded by CG8422 is a functional receptor for a diuretic hormone, DH44. Here, we report that the other CRF receptor subfamily member, encoded by CG12370, is also a receptor for the DH44 neuropeptide. The lines of evidence to support this identification include increases in cAMP levels due to CG12370 receptor activation and the recruitment of β-arrestin–GFP to the plasma membrane in response to DH44 application. We compared these features of the receptors DH44-R2 (encoded by CG12370) and DH44-R1(encoded by CG8422) and found fundamental differences in signaling,association with the arrestins, and peptide sensitivity. We found that the sensitivity of DH44-R2 to the DH44 peptide is lower than that of DH44-R1, specifically an estimated EC50 of 7.98E-07 moll–1 for DH44 by DH44-R2 to an EC50of 5.12E-09 moll–1 by DH44-R1 and found that previous reports on the sensitivity of the tubule to DH44 is in agreement with our measurements of DH44-R2 sensitivity. We employed a specific RNAi construct to selectively knock-down DH44-R2 expression and this led to heightened sensitivity to osmotic challenges. The functional characterization of this diuretic hormone receptor in Drosophila demonstrates a high degree of conservation of CRF-like signaling.
Electrochemically Modulated Film Permeability: A Functional Film for Controlled Reagent Release
Authors: Sahni Himanshu , Villalba Maria Marti , Newton Laura A A , Leslie Ray , Davis James
Published: September 2009

The electrochemical transformation of an insoluble quinone layer has been investigated as the basis of a smart material and its applicability for reagent delivery applications has been assessed. The quinone is shown to form a protective layer whose permeability and susceptibility toward dissolution can be modulated through the imposition of an appropriate electrochemical trigger.
Syntheses and Photochromic Properties of Metacyclothiophenophan-1-enes
Authors: Takeshita Michinori , Jin-nouchi Hirotsugu , Ishikawa Jun
Published: September 2009

A small thia[3]metacyclo[2]thiophenophan-1-ene, cyclo-phane composed of a thiophene ring, a benzene ring, and their bridge, has been synthesized and displays photochromism, while a metacyclothiophenophan-1-ene bearing a long bridge was non-photochromic due to little conjugation between three double bonds, that was estimated by DFT calculations.
Indoleamine 2,3-Dioxygenase Tissue Distribution and Cellular Localization in Mice: Implications for Its Biological Functions
Authors: Dai Xiangchen , Zhu Bao Ting
Published: September 2009

Earlier studies have suggested that indoleamine 2,3-dioxygenase (IDO) has a wide tissue distribution in mammals. However, detailed information on its cellular localization and also the levels of expression in various tissues is still scarce. In the present study, we sought to determine the cellular localization of IDO and also to quantify the level of its expression in various mouse tissues by using the branched DNA signal amplification assay, Western blotting, and immunohistochemical staining. The highest levels of constitutive IDO expression were found to be selectively present in the caput of epididymis, except for its initial segment. IDO expression was also detected inside the luminal compartment and even in the stereocilia within this region. In the prostate, high levels of IDO were selectively expressed in the capsular cells. In addition, high levels of IDO expression were also selectively detected in certain types of cells in the placenta, spleen, thymus, lung, and digestive tract. Notably, the morphological features of most of the positively stained cells in these organs closely resembled those of antigen-presenting cells. Based on the tissue distribution and cellular localization characteristics of IDO, it is hypothesized that its expression may serve two main functions: one is to deplete tryptophan in an enclosed microenvironment (such as in the epididymal duct lumen) to prevent bacterial or viral infection, and the other is to produce bioactive tryptophan catabolites that would serve to suppress T-cell-mediated immune responses against self-antigens, fetal antigens, or allogeneic antigens, in different situations.
Oral Fluid Testing for Drugs of Abuse
Authors: Bosker Wendy M , Huestis Marilyn A
Published: September 2009

Background: Oral fluid (OF) is an exciting alternative matrix for monitoring drugs of abuse in workplace, clinical toxicology, criminal justice, and driving under the influence of drugs (DUID) programs. During the last 5 years, scientific and technological advances in OF collection, point-of-collection testing devices, and screening and confirmation methods were achieved. Guidelines were proposed for workplace OF testing by the Substance Abuse and Mental Health Services Administration, DUID testing by the European Union’s Driving under the Influence of Drugs, Alcohol and Medicines (DRUID) program, and standardization of DUID research. Although OF testing is now commonplace in many monitoring programs, the greatest current limitation is the scarcity of controlled drug administration studies available to guide interpretation.

Content: This review outlines OF testing advantages and limitations, and the progress in OF that has occurred during the last 5 years in collection, screening, confirmation, and interpretation of cannabinoids, opioids, amphetamines, cocaine, and benzodiazepines. We examine controlled drug administration studies, immunoassay and chromatographic methods, collection devices, point-of-collection testing device performance, and recent applications of OF testing.

Summary: Substance Abuse and Mental Health Services Administration approval of OF testing was delayed because questions about drug OF disposition were not yet resolved, and collection device performance and testing assays required improvement. Here, we document the many advances achieved in the use of OF. Additional research is needed to identify new biomarkers, determine drug detection windows, characterize OF adulteration techniques, and evaluate analyte stability. Nevertheless, there is no doubt that OF offers multiple advantages as an alternative matrix for drug monitoring and has an important role in DUID, treatment, workplace, and criminal justice programs.
Plasma MicroRNAs as Sensitive and Specific Biomarkers of Tissue Injury
Authors: Laterza Omar F , Lim Lee , Garrett-Engele Philip W , Vlasakova Katerina , Muniappa Nagaraja , Tanaka Wesley K , Johnson Jason M , Sina Joseph F , Fare Thomas L , Sistare Frank D , Glaab Warren E
Published: September 2009

Background: MicroRNAs (miRNAs) are endogenous, small noncoding RNAs. Because of their size, abundance, tissue specificity, and relative stability in plasma, miRNAs hold promise as unique accessible biomarkers to monitor tissue injury.

Methods: We investigated the use of liver-, muscle- and brain-specific miRNAs as circulating biomarkers of tissue injury. We used a highly sensitive quantitative PCR assay to measure specific miRNAs (miR-122, miR-133a, and miR-124) in plasma samples from rats treated with liver or muscle toxicants and from a rat surgical model of stroke.

Results: We observed increases in plasma concentrations of miR-122, miR-133a, and miR-124 corresponding to injuries in liver, muscle, and brain, respectively. miR-122 and miR-133a illustrated specificity for liver and muscle toxicity, respectively, because they were not detectable in the plasma of animals with toxicity to the other organ. This result contrasted with the results for alanine aminotransferase (ALT) and aspartate aminotransferase, which were both increased with either organ toxicity. Furthermore, miR-122 exhibited a diagnostic sensitivity superior to that of ALT when the results were correlated to the liver histopathologic results. The miR-124 concentration increased in the plasma of rats 8 h after surgery to produce brain injury and peaked at 24 h, while the miR-122 and miR-133a concentrations remained at baseline values.

Conclusions: These results demonstrate that tissue-specific miRNAs may serve as diagnostically sensitive plasma biomarkers of tissue injury.
Advanced Crew Escape Suits (ACES) Particle Impact Test
Authors: Rosales Keisa R. , Stoltzfus Joel M.
Published: September 2009

NASA Johnson Space Center requested NASA JSC White Sands Test Facility to assist in determining the effects of impaired anodization on aluminum parts in advanced crew escape suits (ACES). Initial investigation indicated poor anodization could lead to an increased risk of particle impact ignition, and a lack of data was prevalent for particle impact of bare (unanodized) aluminum; therefore, particle impact tests were performed. A total of 179 subsonic (Test Series 1–3) and 60 supersonic (Test Series 6) tests were performed with no ignition of the aluminum targets. Based on the resulting test data and analysis, WSTF found no increased particle impact hazard was present in the ACES equipment.
An Approach to Understanding Flow Friction Ignition: A Computational Fluid Dynamics (CFD) Study on Temperature Development of High-Pressure Oxygen Flow Inside Micron-Scale Seal Cracks
Authors: Hooser Jared D. , Wei Mingjun , Newton Barry E. , Chiffoleau Gwenael J. A.
Published: September 2009

Flow friction ignition of non-metallic materials in oxygen is a poorly understood heat-generating mechanism thought to be caused by oxygen flow past a non-metallic sealing surface. Micron-scale fatigue cracks or channels were observed on non-metallic sealing surfaces of oxygen components and could provide a leak path for the high-pressure oxygen to flow across the seal. Literature in the field of micro-fluidics research has noted that viscous dissipation, a heat-generating mechanism, may not be negligible as the flow dimension of the channel is reduced to the micron-scale. Results of a computational fluid dynamics study are presented and used to determine if temperatures developed in high-pressure driven micro-channel oxygen flows are capable of reaching the reported autogenous ignition temperature of non-metallic materials in oxygen.
Good Practices for Avoiding Fires in Steel Mill Oxygen Systems
Authors: Forsyth Elliot T. , Newton Barry E. , Chiffoleau Gwenael J. A. , Brophy Brendan
Published: September 2009

Over time, oxygen has been used with increasing frequency in the steel industry. Applications include basic oxygen furnaces, electric arc furnaces, scrap melting, lancing operations, and slab-cutting operations. Because of the inherently “dirty” environment of most steel mills, avoiding contaminants in the oxygen systems can be challenging and numerous fires have occurred due to contaminant-promoted ignition sources. This paper presents many good practices that can be practically implemented to reduce the risk of oxygen fires in typical steel mill oxygen system installations.
Liquid Oxygen Rotating Friction Ignition Testing of Aluminum and Titanium with Monel® and Inconel® for Rocket Engine Propulsion System Contamination Investigation
Authors: Peralta Stephen F. , Rosales Keisa R. , Stoltzfus Joel M.
Published: September 2009

Metallic contaminant was found in the liquid oxygen (LOX) pre-valve screen of the shuttle main engine propulsion system on two orbiter vehicles. To investigate the potential for an ignition, NASA Johnson Space Center White Sands Test Facility performed (modified) rotating friction ignition testing in LOX. This testing simulated a contaminant particle in the low-pressure oxygen turbo pump (LPOTP) and the high-pressure oxygen turbo pump (HPOTP) of the shuttle main propulsion system. Monel® K-500 and Inconel® 718 samples represented the LPOTP and HPOTP materials. Aluminum foil tape and titanium foil represented the contaminant particles. In both the Monel® and Inconel® material configurations, the aluminum foil tape samples did not ignite after 30 s of rubbing. In contrast, all of the titanium foil samples ignited regardless of the rubbing duration or material configuration. However, the titanium foil ignitions did not propagate to the Monel and Inconel materials. Based on these results, NASA determined that the risk of a fire occurring in the turbo pumps was acceptably low.
Relation Between Actual and Artificial Weathering of Organic Materials
Authors: Reinhart FW
Published: September 2009

Laboratory tests can be controlled fairly well. However, outdoor exposure tests are at the mercy of the weather. The temperature, relative humidity, sunshine, and rain vary not only from one geographical location to another but also at the same location from month to month and from year to year. These variations are of sufficient magnitude so that actual outdoor exposure tests made in one particular year and in only one or two localities cannot be considered as a standard for rating the performance of laboratory simulated (artificial) weathering tests. Outdoor exposure tests intended for evaluating the reliability of artificial weathering tests should be made over several years in several localities.
Closing Comments
Authors: Shuman EC
Published: September 2009

There is profound food for thought in all of the papers. It is notable that the item mentioned most frequently is a long standing enemy—water; what it will do itself, and what it will do by carrying other materials with it. Another item was weather, not only as given in general terms, but as Mr. Reinhart pointed out, in terms of variations for a given locality. This I think was a major contribution.
Spectrographic Determination of Trace Elements in Metals
Authors: Nokris JA
Published: September 2009

The problem of the determination of trace quantities of impurities in metals has existed almost since the time of the first metal preparations of the cave men and exists today in the newest proposed alloys for high-temperature use or reactor construction. During this span of time only the definition of trace has changed. In early times, a trace might have been considered to be any quantity in the low percentage range; at present, we are most likely to define the term with reference to the field of endeavor in which we work. Current thinking in some metallurgical fields might define a trace to be 1000 ppm or less while in another area of operations it might well mean 1 ppm. In the field of semiconductors covered by James M. Morris, and Francis Pink, in this symposium, he might well refer to parts per billion as a trace impurity. In order to be able to limit the scope of this paper, the value of 100 ppm has arbitrarily been chosen as an upper limit for trace elements in metals.
Principles of Quantitative Biological Emission Spectrography
Authors: Vallee BL
Published: September 2009

For the past eight years our laboratory has devoted its main efforts to the development of emission spectrography as a tool in biological investigation. As in other scientific disciplines, workers in biology have been impressed with the sensitivity of the d-c arc, while they have deplored its lack of precision and have regretted that the precise, high-voltage spark is not more sensitive. Our work with helium, argon, neon, and krypton, aimed at improving sensitivity both by effects on line intensity and on signal-noise ratio, have been documented previously and do not require further discussion here (1–6). While adding basic knowledge and extending analytical techniques, these studies have not led to dramatic answers of technical problems which have beset other workers in many areas of application of emission spectrography. Just the same, a good deal has been learned in the process; we have certainly been able to answer many biological questions. From a spectrographer's point of view, however, this inquiry, while having resulted in a very satisfactory technique, has not yielded the kind of progress all of us undoubtedly strive for: the universal method, based on new principles.
Marine Exposure Tests of Pressure-Treated Douglas Fir and Southern Pine
Authors: Graham R. D. , Miller D. J.
Published: September 2009

Dried lumber pieces of Douglas fir heartwood and sapwood and southern pine sapwood (3/4 by 3 by 18 in.) were treated by the full-cell process with creosote and creosote — coal tar in a 70-30 per cent solution. Douglas fir sapwood pieces also were treated with ammoniacal copper arsenite (Chemonite) and with copper formate. Average retentions in pounds per cubic foot were: creosote, 35.7; creosote — coal tar, 33.7; Chemonite, 0.38; and copper formate, 0.28.

Specimens were installed during the summer and fall of 1957 at three marine exposure sites on the Pacific Coast and three sites on the Atlantic Coast of the United States. Douglas fir sapwood pieces treated with each preservative were installed at all sites. Douglas fir heartwood pieces were installed at three Pacific Coast sites and one Atlantic Coast site. Pine specimens were installed at two Atlantic Coast sites.

Specimens were mounted on galvanized steel bars in replicates of five. Pieces treated with creosote and creosote — coal tar were mounted on bars numbered 1 through 5 in such a way that each bar contained a complete set of treated replicates and two untreated panels. Bars 6 and 7 contained five replicates of pieces treated with Chemonite and with copper formate, respectively.

One bar of specimens treated with creosote and creosote — coal tar, and one replicate from both bars 6 and 7 will be removed permanently every two years. These specimens will be examined closely and related according to a standard procedure as to extent and cause of deterioration. Results of the first biennial inspection are reported.
Application of the Cone-Plate Viscometer to Non-Newtonian Systems
Authors: Forster E. O. , Horowitz H. H.
Published: September 2009

Many petroleum products are both non-Newtonian (the shear stress versus shear rate relation is nonlinear) and thixotropic (the viscosity is work- or time-dependent). Greases and waxy lubricating oils, especially those containing polymeric additives, at low temperatures are examples of materials which show this dual complexity. Viscometers for such materials must be able to reach well-defined shear stresses and shear rates and should permit control of the work history of the sample up to the time of measurement, with minimum interference from temperature or edge or end effects. Because of its design and construction, the thin-film cone-plate viscometer meets these requirements. Preliminary results with this viscometer indicate that it will prove to be especially well suited for measuring the low-temperature viscosities of waxy lubricating oils. It gives results which correlate with engine cold-cranking performance.
Description and Performance of a New Electro-Vibration Polishing Method
Authors: Petzow Günter , Baer Karin
Published: September 2009

To shorten the long polishing time of vibration polishing of metallographic specimens, an electrochemical effect was added. Therefore, a stainless steel plate was welded into the PVC inlet of a vibration apparatus as cathode. The specimen (anode) was connected with a sliding contact to a copper grid supplied by an ac-dc power control unit. In order to prevent analytic reactions, the 800-g lead weight was coated by poly(vinyl chloride) (PVC). To give a successful combination, the important factors of both the mechanical vibration polishing and the electrolytic polishing must harmonize. The mechanical abrasion must be kept strong to control the electrolytic attack, while the electropolishing conditions are determined by plotting a current density-voltage curve. The method has been applied successfully to pure metals as well as to homogeneous alloys. Owing to the appreciable shortening of polishing time and the high surface quality of even very soft materials, it is a valuable addition to vibration polishing.
Criteria for Application of Hot-Stage Transmission Electron Microscopy to the Study of Physical Metallurgy
Authors: Laird C.
Published: September 2009

Application of the electron microscope hot stage can provide unequivocal evidence for the nature of thermal processes. The difficulties inherent in the technique, however, have minimized its use up to the present. In particular these difficulties are: (1) the intervention of surface diffusion (not characteristic of bulk processes) due to the large surface area of thin foils, (2) the differences in mechanisms of both sheartype and diffusional processes which sometimes develop between thin foils and bulk materials, (3) the contamination of reactive materials by the environment provided by present electron microscopes, (4) the changes in contrast conditions of thin foils congruent with expansion of their lattices and with buckling due to thermal strains, and (5) the inaccuracy of measuring the temperature of the foil while being observed. Methods of circumventing these difficulties are described. Criteria for the successful application of the hot stage are established in view of these difficulties. It is concluded that the type of phenomenon best treated by means of the hot stage is one occurring on the scale of hundreds of angstroms but not greater than 0.2 μ to prevent interference by the foil surface, and repeating at intervals of the order of microns in order to increase the probability of obtaining results, particularly when using ciné techniques. Thus, very fruitful studies of continuous and discontinuous precipitation processes, ordering reactions, and recovery phenomena may be made with ease, while investigations into recrystallization or certain martensitic transformations are not likely to be successful unless extensive preliminary studies are made.
Electron Microstructure Study of an Iron-Nickel Base Heat-Resistant Alloy Containing Cobalt
Authors: Maniar G. N. , James H. M.
Published: September 2009

An electron microstructure study was carried out to understand the precipitation behavior of age-hardening gamma-prime in an iron-nickel base high temperature alloy, Pyromet 860, containing 4 weight per cent cobalt. Carbon extraction replica and thin foil transmission electron microscopy were used. The extraction replica study showed gamma-prime to have many random orientations in addition to some preferred orientation. The thin film microscopy did not show any contrast effect due to coherency strains and confirmed many orientations of gamma-prime precipitates.
Progress in Quantitative Electron Probe Microana lysis
Authors: Criss J. W.
Published: September 2009

Problems in making well-defined homogeneous standards have limited the use of calibration curves and empirical formulas for quantitative electron probe analysis. Consequently, much effort in the last three years has been devoted to further study of the interactions of electrons and X-rays with matter. The goal has been to obtain more accurate values for the fundamental physical parameters, and to find better expressions to relate specimen composition and measured characteristic X-radiation. Measurements have been made of mass absorption coefficients, the electron excitation function, and the absorption correction function. The increasing availability of computers has tended to remove the restriction of simplicity in intensity formulas, so that the physical processes have been considered in more detail. In addition, computers have permitted more accurate studies of electron penetration, through Monte Carlo techniques and numerical solution of the transport equation. These latter approaches in turn have increased the need for accurate values of parameters describing the interactions of electrons with matter. The result of all these efforts should be better formulas to describe X-ray absorption, the atomic number effect, and fluorescence by characteristic lines and by the continuum.
Scanning Electron Probe Microanalysis
Authors: Heinrich K. F. J.
Published: September 2009

The combination of electron microprobe X-ray emission spectrometry with the scanning techniques first developed for the scanning electron microscope permits using the scanning electron probe as a microscope sensitive to elemental composition. This technique is particularly useful in the many applications in which spatial distribution of one or more elements in a specimen is more important than local composition. Although oscilloscope representation of probe scanning is usually obtained by the simple technique of producing a dot of light for each arriving photon, more sophisticated scanning techniques such as expanded contrast registration and concentration mapping can provide more quantitative information. Signals other than X-rays, such as target current, electron backscatter, or cathodoluminescence may be used for image formation. Electron beam scanning can be also performed in a discontinuous fashion, so that the electron beam irradiates in succession a number of spots arranged in a square rectangular pattern, and the number of photons registered in each position is retained in the memory of a multichannel analyzer. The application of these diverse scanning techniques is illustrated.
Report of the Washington Electron Probe Users' Group
Authors: Birks L. S. , Gilfrich J. V. , Yakowitz H.
Published: September 2009

The Washington Electron Probe Users' Group which consists of approximately 35 persons representing some twelve laboratories in the area was established in December, 1964. This group meets monthly for an informal exchange of information concerning current research practices and techniques. Instruments of three commercial firms, as well as laboratory constructed instruments, are represented. It became apparent to the group that there were problems of importance which could not be resolved through discussion alone. In order to clarify these problems, several systems of alloys and minerals were carefully selected for collective study and comparison. Wherever possible, these systems were chosen so that absorption, fluorescence, and atomic number factors could be individually evaluated. For example, in the iron-nickel system only an absorption conversion is required for nickel, while a relatively large fluorescence correction is necessary for the iron. In each of these tests, relative X-ray intensity data taken from instruments of the same manufacturer were compared in order to determine variations in the measurement process; in virtually all cases, agreement was excellent. Thus, it was deemed possible to evaluate conversion procedures for their relative merits. In cases where absorption is important, the major source of variability has been the X-ray mass absorption coefficient uncertainty rather than the conversion procedure. Also, when fluorescence corrections are required, the available conversion procedures seem to lead to results having approximately the same variability. The need for an atomic number conversion has been established, but the variability associated with the procedures postulated in the literature leads to greater uncertainty than the absorption or fluorescence conversion or both; this may be due to the fact that no completely acceptable theoretical basis for this conversion has yet been proposed. In all of this work, an interesting observation has been that addition of the concentrations to 100 per cent is not a suitable criterion for judging the correctness of either the measured data or the conversion procedure. As a result of the experience of the Washington Electron Probe Users' Group, advantages to individual laboratories from such group participation can and will be pointed out and suggestions given for the formation of electron probe users' groups in other sections of the country.
The Effect of Cold Work, Thermal Treatment, and Neutron Irradiation on the Fracture Toughness of Zircaloy-2
Authors: Rowe R. G. , Hoagland R. G.
Published: September 2009

Neutron irradiation of annealed Zircaloy-2 in a 280 C pressurized water environment has been found to cause a considerable loss in fracture toughness. Generally, however, Zircaloy-2 is utilized in PWR systems in a cold worked condition. This paper supplements previous work by presenting the results of an experimental study of the fracture characteristics of cold-worked Zircaloy-2. The results are obtained from a parametric analysis of the temperature- and orientation-dependence of Kic as influenced by cold work, hot pressurized water, and neutron irradiation.
Irradiation Effects in Pressure Vessel Materials for Steam-Cooled Fast Reactors
Authors: Grounes M. , Lindhagen P.
Published: September 2009

Steam-cooled fast reactor pressure vessels must withstand high pressures (130–230 atm) and high neutron doses, for example, 5 × 10 20 n/cm 2 (>1 MeV). Two new steels have been investigated, a 16 Cr-5 Ni-1 Mo steel (Avesta 248 SV) and a 13 Cr-6 Ni-1.5 Mo steel (Bofors 2 RMO). Their tensile strengh is above 70 kg/mm2 at 300 C. The steels are unusually tough at low temperatures, and there is no sharp brittle-to-ductile transition. Various properties of the steels are described.

Impact and tension specimens have been irradiated in two thermal reactors at 60 to 550 C. After 3.2 × 1019 n/cm2 (>1 MeV) at 265 C, the temperature at 4.2 kg-m impact energy has been increased 100 C to —90 C. Tension tests show a small decrease or an increase in ductility because of irradiation.

To draw conclusions from these experiments the differences in neutron spectra between the materials testing reactors and the fast reactor vessel have to be taken into account. This problem is discussed for two types of damage: displacement damage and transmutation damage. In the former case, an attempt is made to use different damage theories for an engineering type of estimate of the maximum difference between irradiation effects in the two types of spectra. In the later case, an analysis of the transmutation reactions is made.
The Role of Base Oils and Additives in Modern-Day Turbine Oils
Authors: Dolby George W , Kofke William A
Published: September 2009

Modern-day turbine oils are required to: (1) lubricate and cool load-carrying surfaces, (2) maintain viscosity, (3) resist oxidation, (4) provide protection against rusting and other forms of corrosion, (5) resist foaming, and (6) have good water separation characteristics. Good turbine lubricants are compounded from well-refined responsive blending stocks, antioxidants, rust inhibitors, and antifoam additives. Inhibitor response, compatibility, and stability are important factors to be considered when formulating turbine oils.

The properties of turbine oil base stocks depend on three factors: (1) the type or source of crude oil used to produce the raw lubricating oil distillates, (2) the method or process used to refine the raw distillates, and (3) the degree or severity of refinement. Good base oils have high viscosity indexes, low iodine numbers, low pour points, and low sulfur contents. They are also light in color and essentially neutral.

Data are presented on light- and heavy-base oil blending stocks before and after refining by solvent treating, dewaxing, and clay filtering. Furfural and phenol were used, both at two different treating severities to illustrate the effect of process variables on the finished base oils.

Data are also presented on fully inhibited turbine oil blends prepared from the furfural- and phenol-treated oils. The blends were inhibited at two different antioxidant levels to demonstrate base oil inhibitor response. Laboratory inspection data show the differences in inhibitor response as expressed by the oxidation lives obtained on the blended oils by the ASTM oxidation test method (D 943). Other data also show the antioxidant response of an aluminum chloride-treated oil, as well as the response of various hydrofinished turbine oils produced from different crude oils.
Fleet Experience with Navy Turbine Oils—Are Specification Methods Significant?
Authors: King H F , Glassman N
Published: September 2009

U. S. Navy experience with turbine lubricating oil generally has been excellent. This experience is based on a turbine oil consumption rate of 9,000,000 gal per yr in machinery ranging from main propulsion turbines and gearing to hydraulic systems and various machinery auxiliaries. This equipment has transported and been transported by turbine oil to every sea in the world by mighty Polaris submarines and giant aircraft carriers as well as by the less glamorous but essential landing ships dock and others.

The Navy’s turbine oil is competitively procured under a specification composed of performance requirements defined by applicable test methods. The majority of these methods are ASTM procedures. The U. S. Navy’s turbine oil is a sophisticated product possessing a well-refined petroleum oil body containing a balanced additive formulation which makes it a responsible lubricant for key machinery and at the same time a protector of that machinery from attack by rust. It is intended to be noncorrosive, stable to oxidation, nonemulsifying, nonfoaming, and stable in storage.

The wide use of this oil in other than turbine machinery testifies to its generally satisfactory performance. Still, more than isolated instances of oil failure have occurred as in the rusting observed in the gear train of a docked submarine, fretting corrosion in couplings, and the increased maintenance required due to sludging in relatively inaccessible ships' auxiliary machinery. These failures lead to the recognition that improvements in the oil should be sought, and that present tests do not entirely define or predict the types of failure being encountered in service.

This paper recounts the types of failures being encountered, the inability of present tests to predict oil rust protection and oxidation stability, and suggests approaches to improve the situation.
The 1962 Status of Test Sequences I, II, and III
Authors: Bennett P. A. , Kabel R. H.
Published: September 2009

The ASTM Test Sequences have gradually gained recognition as useful tools for defining motor oil quality (1). For example, Sequences I, II, and III are being used to evaluate new motor oil formulations in 19 laboratories. They are also used in factory-fill and U.S. Army Ordnance motor oil specifications.

Although repeatability and reproducibility have been serious problems in some laboratories, others have established that satisfactory results can be obtained. Several variables that recent experience has shown to be important test parameters are discussed. Test modifications resulting from a reevaluation of these variables are included.
Factory-Service Automatic Transmission Fluid Requirements
Authors: Sprague S. R. , Woodruff R. L.
Published: September 2009

Factory-service automatic transmission fluids possess physical properties and performance features which differ substantially from the minimum Type A, Suffix A specification requirements. In some cases either the transmission life would be impaired by the use of a minimum Type A, Suffix A fluid, or desirable performance features would be deteriorated. These special factory requirements are discussed including low-temperature fluidity, frictional properties, clutch durability, antiwear characteristics, elastomer compatibility, and oxidative stability. The specialty factory fluids present questions concerning make-up oil additions and drain and refill practices. In spite of these, however, transmission manufacturers will continue to include the lubricant as an integral part of the total design. Thus service-station fluids should be carefully chosen to compromise manufacturers' conflicting recommendations.
Why High Performance Gear Lubricants at Service Stations?
Authors: Grance H. J.
Published: September 2009

The object of this paper is to call attention to the need for high-performance gear lubricants at retail service stations. These lubricants, of the generally accepted API Service GL-4 type, are those represented by their manufacturers to have adequate load-carrying ability for protection of gears in sustained high-speed and high-torque service in modern, high-powered passenger cars and trucks. A plea is made for the establishment, through ASTM, of improved methods for communication between the automotive and petroleum industries, by the development of test procedures to indicate the quality desired, which are already furnished in products referred to by such terms as GL-4. Principal reasons for the decision to feature these improved lubricants for distribution through retail stations are discussed.
The Development of Artificial Heart Valves
Authors: Davila J. C.
Published: September 2009

In the development of cardiac valves we are constrained by various factors, materials, perhaps, is the most important. In addition, we must adapt design to the geometry or anatomy of the region in which we are working, the influence of which must be of major consequence in the performance of the devices that we develop. We are primarily concerned with two valves, the mitral and aortic, although one other, the tricuspid, is sometimes in need of replacement.
Abstract Antigenicity of Synthetic Polypeptide Antigens
Authors: Maurer P. H.
Published: September 2009

Investigations of the immune response against straight-chain homopolymers, random linear copolymers, and branched multichain polymers of amino acids have employed rabbits, guinea pigs, mice, and humans. These studies from several laboratories have inquired into the structural bases of antigenicity and into several of the parameters contributing to immunogenicity. The straight-chain polymers resemble the fibrous proteins, and the multichain polymers simulate the globular proteins. Linear homopolymers of L or D amino acids and copolymers consisting only of D amino acids are not antigenic. The presence of two L amino acids in a random copolymer is a necessary but not sufficient criterion for antigenicity. The ratio of amino acids in the copolymer is a much more important immunogenic determinant than is the net charge of the polymers. The helix content does not appear to influence antigenicity. Increasing the number of amino acids in a polymer increases the immunogenicity which is now known to vary among species. Research with multichain polymers had indicated (a) the importance of accessibility of an immunogenic configuration for antigenicity and (b) methods of converting antigenic polymers to nonantigenic polymers.