bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is there life in the horny layer? Dihydropyridine and ryanodine receptors in the skin of female and male chickens (Gallus domesticus)
Authors: Peltonen Liisa M. , Mänttäri Satu 
Published: April 2008

SUMMARY
Previous findings in pigeons and chickens show that Ca2+ may be accumulated inside the cornified skin cells and that Ca2+microenvironments with a lower- or higher-than-blood concentration may exist in the skin. It has been suggested that the skin may function as a secretory pathway or a reservoir for Ca2+ recycling. To test this hypothesis,we studied the dermis and epidermis of female and male chickens in vivo to find out whether cellular mechanisms exist for the accumulation,recycling or secretion of Ca2+. For calcium influx and intracellular Ca2+ release, respectively, the density of dihydropyridine receptors (DHPRs) and ryanodine receptors (RyRs) was examined,using high-affinity (–)-enantiomers of dihydropyridine and ryanodine labelled with fluorophores. To investigate Ca2+ utilization in the skin, the systemic and local activity of the enzyme alkaline phosphatase (ALP)and the concentration of ionic Ca2+ were measured in plasma and in cutaneous extracellular fluid, collected by suction blister technique. We found that both DHPRs and RyRs were present in all skin layers from dermis to horny layer. However, receptor densities were highest in the surface layers. With a basic calcium-rich diet, receptor densities were higher in males,particularly in the dermis and mid-epidermis. After a reduction in the nutritional Ca2+ input, receptor densities in males decreased to the same level as in females, in which the receptor densities were not affected by the amount of Ca2+ in the diet or that resulting from coming out of lay. The extracellular concentration of ionic Ca2+per se was not found to affect the density of DHPRs and RyRs in the skin. Spatially, RyRs seem to be located in the periphery of the sebokeratinocyte. ALP activity was shown to be lower in the extracellular fluid than in the plasma in both sexes. However, activity in both extracellular domains increased significantly in females that had come out of lay. This was probably connected with the increased osteoblast activity related to the reformation of structural bone. In conclusion,voltage-sensitive L-type Ca2+ channels for ion influx and RyRs for Ca2+ release are present in the cells of the skin of female and male chickens. Higher densities in the males receiving excessive Ca2+ imply an increased capacity for Ca2+ influx and intracellular processing. Even though the functional interactions between DHPRs and RyRs in the sebokeratinocytes could not be demonstrated, peripheral colocation and high receptor densities at the level of exocytosis of the lamellar bodies point to their role as part of a signalling pathway for secretion. The finding that DHPRs and RyRs are present in the horny layer implies that the function of the outermost skin might be more active than had been previously thought and that this function might be both secretory and sensory.
The pyloric neural circuit of the herbivorous crabPugettia productashows limited sensitivity to several neuromodulators that elicit robust effects in more opportunistically feeding decapods
Authors: Dickinson Patsy S. , Stemmler Elizabeth A. , Christie Andrew E. 
Published: April 2008

SUMMARYModulation of neural circuits in the crustacean stomatogastric nervous system (STNS) allows flexibility in the movements of the foregut musculature. The extensive repertoire of such resulting motor patterns in dietary generalists is hypothesized to permit these animals to process varied foods. The foregut and STNS of Pugettia producta are similar to those of other decapods, but its diet is more uniform, consisting primarily of kelp. We investigated the distribution of highly conserved neuromodulators in the stomatogastric ganglion (STG) and neuroendocrine organs of Pugettia,and documented their effects on its pyloric rhythm. Using immunohistochemistry, we found that the distributions of Cancer borealis tachykinin-related peptide I (CabTRP I), crustacean cardioactive peptide (CCAP), proctolin, red pigment concentrating hormone (RPCH) and tyrosine hydroxylase (dopamine) were similar to those of other decapods. For all peptides except proctolin, the isoforms responsible for the immunoreactivity were confirmed by mass spectrometry to be the authentic peptides. Only two modulators had physiological effects on the pyloric circuit similar to those seen in other species. In non-rhythmic preparations,proctolin and the muscarinic acetylcholine agonist oxotremorine consistently initiated a full pyloric rhythm. Dopamine usually activated a pyloric rhythm,but this pattern was highly variable. In only about 25% of preparations, RPCH activated a pyloric rhythm similar to that seen in other species. CCAP and CabTRP I had no effect on the pyloric rhythm. Thus, whereas Pugettiapossesses all the neuromodulators investigated, its pyloric rhythm, when compared with other decapods, appears less sensitive to many of them, perhaps because of its limited diet.
Application of the Small-Punch Test to Irradiated Reactor Vessel Steels in the Brittle-Ductile Transition Region
Authors: Linse T. , Kuna M. , Schuhknecht J. , Viehrig H.-W. 
Published: April 2008

Abstract
In this paper, a method is applied for the identification of hardening parameters in the brittle-ductile transition region and the determination of Weibull parameters in the brittle region using small-punch tests. A small-punch-test device is developed to measure the load-displacement curve for non-irradiated and irradiated specimens of a reactor vessel steel at different temperatures inside a hot cell. In a global optimization algorithm for the identification of hardening properties, time-consuming finite element method (FEM) calculations are avoided by using neural networks that were trained with the help of a database previously generated by FEM. Identified material properties are compared with data from tensile tests, where available. The influence of irradiation and temperature on the material and fracture behavior is analyzed.
Improvement of Stress Corrosion Cracking (SCC) Resistance by Cyclic Pre-Straining in FCC Materials
Authors: de Curiere I , Bayle B , Magnin T 
Published: April 2008

Improving the materials resistance to SCC has become a topic of wide interest for theoretical, engineering and financial reasons. The aim of this paper is to propose a process to delay the SCC damage. Recent studies of 316L austenitic stainless steel in boiling MgCl2 solutions show an improvement in SCC resistance by cyclic pre-straining in low cycle fatigue [1]. This improvement consists of an increase in both strain to failure and crack initiation strain, during Slow Strain Rate Tensile (SSRT) tests in aqueous solution.
This paper analyses the effect of pre-fatigue in 316L and copper on their mechanical and electrochemical responses to better understand the delay of SCC damage in boiling MgCl2 and nitrite, respectively.
The explanation for this beneficial effect is related to a modification of both surface electrochemical reactions kinetics and corrosion/plasticity interactions at the crack tip, due to the particular fatigue dislocation structure.
Premature Failures of Copper Alloy Valves and Fittings in the New York City Water Supply System
Authors: Andersen GA 
Published: April 2008

Copper alloys are used in various water main components in The New York City Water Supply System. Three copper alloys have been found to fail prematurely. Two manganese bronzes, Copper Development Association (CDA) alloys C86500 and C86300, have previously [1] been found to fail in valves and shaft caps as well as nut fasteners in transgranular and intergranular stress corrosion cracking (SCC) modes, respectively.
A valve stem, made of alloy C86500, has just recently been found to fail what appears to be from SCC, but in a combination of transgranular and intergranular modes. Tapping goose necks, and a pressure regular stem made of CDA alloy C83600, have been found to fail prematurely. Failure analyses of the goose necks and the pressure valve stem have been performed; they appear to have failed from SCC with the lead reacting with water. The lead may create an environmental health problem by being absorbed by the potable water and supplied to the buildings they are serving. To corroborate the aforementioned failure analyses, specimens made of alloy C86500 and C83600 were machined from a valve stem and a goose neck respectively and tested in a laboratory with simulated environments. This paper presents the case histories of the two SCC type failures and what action is being taken to remedy these problems.
Improved Response of Turbine Oils Based on Group II Hydrocracked Base Oils Compared with Those Based on Solvent Refined Base Oils
Authors: Schwager BP , Hardy BJ , Aguilar GA 
Published: April 2008

Modern industrial equipment makes increasingly severe demands on the lubricating oils used to keep the equipment running. Higher operating temperatures, smaller oil reservoirs, and decreased downtime all help create a severe environment for the lubricant. In response, base oil manufacturers have developed new technology to provide more saturated, high-performance base oils using catalytic hydrocracking technology. Lubricants based on these base oils and properly matched with the right additive technology have longer oxidation life, less deposit forming tendencies, and overall higher performance than solvent refined products.
In this paper, the performance properties of lubricants based on hydrocracked Group II base oils are compared with those of more traditional products based on solvent refined base stocks. Laboratory tests such as the Rotating Pressure Vessel Oxidation Test (ASTM D2272), the Turbine Oil Oxidation Stability Test (ASTM D943), and the Water Separability Test (ASTM D1401) were used to predict performance. The lubricants tested were all from the general category of rust and oxidation inhibited oils (R&O oils), and included turbine oils. In some cases, actual performance was verified in field trials. The data presented confirm the performance advantages of a properly formulated lubricant based on Group II hydrocracked stocks.
Some Limitations in the Use of Urine Biomonitoring for Measuring TDI Exposure
Authors: Chappelle AH , Shiotsuka RN , Bartels MJ 
Published: April 2008

Although reliable methods are available to monitor the concentrations of TDI in workplace air, some investigators use urine testing methods to determine if a worker has been recently exposed to TDI. This method relies on sophisticated analytical techniques in which various metabolic or breakdown products of TDI present in urine are converted in the laboratory to a derivative, toluene diamine (TDA). The total amount of converted TDA measured in the urine has been proposed as an estimate of exposure to TDI, assuming that an individual has not been exposed to another source of TDA.
Results of TDI biomonitoring may be difficult to interpret and the following points must be considered: 1) The pathway for TDI elimination has not been fully investigated in humans, a direct correlation between TDI air monitoring and urine TDA levels is not feasible; 2) Studies of TDI exposures in the workplace have not consistently shown a good correlation between air exposure levels and biomonitoring results; 3) Biomonitoring for TDI exposure by measuring converted TDA in urine does not identify peak exposures which may be more relevant to pulmonary sensitization; 4) Urine monitoring results for TDI exposure have not been correlated to adverse health effects and no biological monitoring limit has been established for TDI; 5) The detection of converted TDA in laboratory assays on processed urine samples does not necessarily reflect the presence of free TDA in the body, therefore it may unintentionally introduce concerns related to airborne TDI exposures.
Data generated from urine biomonitoring for exposure toTDI must be interpreted with caution and significant questions remain regarding the relevance of these studies for quantitative TDI exposure assessment.
Aircraft Hydraulic Pump Tests with Advanced Fire-Resistant Hydraulic Fluids
Authors: Sharma SK , Snyder CE , Gschwender LJ 
Published: April 2008

During the development of the fire-resistant hydraulic fluids for DoD (Department of Defense) aircraft, candidate fluids were formulated and then characterized initially by various laboratory bench tests. Endurance pump tests were then conducted on the candidate fluids to validate their performance. Pump tests under accelerated conditions were conducted on three candidate fire-resistant hydraulic fluids and several candidate nonflammable hydraulic fluids, using pressure-compensated axial flow piston pumps and an instrumented, small-volume, closed-loop hydraulic test stand. Case-drain temperature and signal-noise on the pump outlet pressure and the case-drain flow provided better failure indicators than the case-drain flow. The fluids containing viscosity-index-improvers underwent large viscosity losses. No viscosity loss was observed for the fluids that did not contain the viscosity-index-improvers. Lower viscosity fluids performed as well as the higher viscosity fluids in these pump tests. However, the ball-bearing material and the heat treatment had a bigger impact on pump life. Use of an M-50 bearing in place of the AISI-52100 bearing doubled the pump life.
Based upon the laboratory screening tests and the validation pump tests, the best performing fire-resistant hydraulic fluid was recommended for use in the DoD aircraft. Performance of the recommended fluid was further demonstrated in successful aircraft flight tests. Only limited hydraulic system simulator and aircraft subsystem testing has been conducted on the best-performing nonflammable hydraulic fluid candidate to date, but the performance was acceptable.
A Mechanistically-Based Model of Irradiation Damage in Low Alloy Steel Submerged Arc Welds
Authors: Williams TJ , Ellis D 
Published: April 2008

A model of irradiation damage in low alloy steel submerged arc welds has been developed by fitting test reactor data to physically reasonable mathematical equations. The model is underpinned by a substantial amount of microstructural data obtained using small angle neutron scattering, atom probe microscopy and other techniques. These data have been used qualitatively to show that the basic assumptions of the model are reasonable, and assessed quantitatively using the Russell and Brown modulus hardening model.
The model predicts hardness change in welds irradiated at high neutron dose rates as a function of irradiation dose, irradiation temperature and chemical composition. Correlations have been developed to enable Charpy or fracture toughness shift to be predicted from hardness change. In addition, a simple modification to the basic model allows estimation of damage at power reactor dose rates. This has enabled comparison with US surveillance programme data. Possible reasons for the observed differences in data and predictions are discussed. Plans to validate the model by testing material from a decommissioned RPV are outlined.
Vessel Investigation Program of “CHOOZ A” PWR Reactor after Shutdown
Authors: Brillaud C , Grandjean Y , Saillet S 
Published: April 2008

In October 1991 the CHOOZ A PWR plant, operated by the French and Belgian company SENA, was shut down after 24 years. It was the first PWR shutdown in France. According to the EDF life duration project it was decided to perform an examination program on samples taken from the wall of the vessel in order to complete the feedback.
The results obtained show the following: • The embrittlement measured by the pressure vessel surveillance program is representative of that of the Shell determined at different axial and angular locations for the 1/4 of the internal thickness. This observation is consistent with the relative homogeneity of the embrittling elements (Cu, P, Ni) throughout the entire Shell, • The mechanical properties evolution through the wall thickness of the Shell measured after irradiation is interpreted in relation with fluence variation and unirradiated mechanical properties profile through the thickness, • The comparison of direct toughness measurement with the French code RCCM evaluation confirms the safety nature of the conventional approach. For the weld, after an irradiation damage of 2 1019 n.cm-2 (E&gt;1MeV), a margin of the order of the irradiation effect seems to exist.
Composition Effects on the Radiation Embrittlement of Iron Alloys
Authors: Böhmert J , Ulbricht A , Kryukov A , Nikolaev Y , Erak D 
Published: April 2008

The effects of copper, phosphorus and nickel on radiation embrittlement were investigated using an irradiation experiment at surveillance positions in two Russian VVER-type reactors with 8 iron-base testing alloys. Chemical composition varied between 0.015 to 0.42 % Cu, 0.002 to 0.039 % P, 0.01 to 1.98 % Ni, 0.09 to 0.37 % Si, and 0.35 to 0.49 % Mn. Charpy-V impact tests and tensile tests were performed with specimens machined from these alloys. The specimen were tested in the as-received state, in the irradiated state (fluence: 1×1019 and 8×1019 cm-2 [En &gt; 0.5 MeV]) and in the post-irradiation annealed state.
Irradiation produces significant hardening and embrittlement. The effect increases with the Cu and P content. Ni causes an additional embrittlement. It does not depend on the Ni content within the range of 1.1 to 2 % Ni. The irradiation effect can be eliminated by annealing at 475 °C / 100 h but not absolutely in the case of high Cu or P content.
Small angle neutron scattering experiments of these alloys show that not only the volume fraction but also the type of the radiation defects vary in dependence on the composition of the alloys.
Correlation Between Creep Properties and Microstructure of Reduced Activation Ferritic/Martensitic Steels
Authors: Sakasegawa H , Hirose T , Kohyama A , Katoh Y , Harada T , Hasegawa T 
Published: April 2008

Reduced activation ferritic steels (RAFs), JLF-1 (9Cr-2W-V,Ta steel) had been studied as one of the reference materials in the IEA RAF R&D activity, because of its superior resistance to high-fluence neutron irradiation up to 100 dpa.
Recently, JLS-series (9Cr-xW-V,Ta steels; x=2.5, 3.0 and 3.5) have been produced as options for RAFs for use at higher temperatures in advanced blanket systems. In this series, improved high temperature mechanical properties were intended by increased tungsten contents.
The creep properties improved with the tungsten contents. A microstructural examination after creep rupture test revealed differences with a increase of tungsten content from 2.0 (JLF4) to 3.0 wt% (JLS-2). According to the examination of tested specimens (100 MPa, 700°C), more intragranular fine precipitates and more intergranular precipitates formed preferentially on prior austenite boundaries and martensite lath boundaries were found in JLS-2 than in JLF-1, martensite lath widths became narrower and dislocation density increased with the increase of tungsten content.
Such microstructural features are likely to improve the creep properties by inhibiting grain evolution, microstructural recovery and strengthening grain boundaries at elevated temperatures.
Comparison of Thermal Creep and Irradiation Creep of HT9 Pressurized Tubes at Test Temperatures from ∼490°C to 605°C
Authors: Toloczko MB , Grambau BR , Garner FA , Abe K 
Published: April 2008

Pressurized creep tubes were used to evaluate the thermal creep behavior and the irradiation creep behavior of several variants of HT9 ferritic-martensitic steel in the temperature range from ∼490°C to 605°C. Examination of the thermal creep data as a function of time showed classic thermal behavior at all the test temperatures. A creep transient was followed by a period of steady state creep which, in some instances, was then followed by tertiary creep. The irradiation creep behavior also displayed a transient followed by steady state creep, but no tertiary creep was observed.
while the thermal creep behavior and the irradiation creep behavior were qualitatively similar, the magnitude of both the transient and the steady state creep rate were often different. At ∼490°C, the thermal creep specimens exhibited a greater transient strain, while at 600°C, the irradiation creep specimens exhibited a greater transient strain. For both the thermal creep specimens and the irradiation creep specimens, the transient strain was observed to increase with increasing applied stress. The steady state creep rates of both the thermal creep specimens and the irradiation creep specimens were observed to increase with increasing temperature. At lower stresses, the steady state creep rates of the thermal creep specimens and the irradiation creep specimens were often equal. At the higher test stresses, the steady state creep rate of the irradiation creep specimens was always higher.
At ∼490°C, the steady state thermal creep rate was observed to have a linear stress dependence up to the highest applied stress of 250 MPa. At 575°C, the stress exponent was between 1.5 and 2 for effective stresses less than 200 MPa. At 605°C, the stress exponent was ∼1 for effective stresses less than 70 MPa. For the irradiation creep specimens, a stress exponent between 1.5 and 2 was observed at ∼490°C and 550°C. At 600°C, the stress exponent was observed to be ∼1.
The Effect of High Energy Protons and Neutrons on the Tensile Properties of Materials Selected for the Target and Blanket Components in the Accelerator Production of Tritium Project
Authors: Maloy SA , James MR , Willcutt GJ , Sommer WF , Johnson WR , Louthan MR , Hamilton ML , Garner FA 
Published: April 2008

The Accelerator Production of Tritium (APT) project proposes to use a 1.0 GeV, 100 mA proton beam to produce neutrons via spallation reactions in a tungsten target. The neutrons are multiplied and moderated in a lead/aluminum/water blanket and then captured in 3He to form tritium. The materials in the target and blanket region are exposed to protons and neutrons with energies into the GeV range. The effect of irradiation on the tensile properties of candidate APT materials, 316L and 304L stainless steel (annealed), modified (Mod) 9Cr-1Mo steel, and Alloy 718 (precipitation hardened), was measured on tensile specimens irradiated in the Los Alamos Neutron Science Center accelerator, which operates at an energy of 800 MeV and a current of 1 mA. The irradiation temperatures ranged from 50–164°C, prototypic of those expected in the APT target/blanket. The maximum achieved proton fluence was 4.5 × 1021 p/cm2 for the materials in the center of the beam. This maximum exposure translates to a dpa of 12 and the generation of 10,000 appm H and 1,000 appm He for the Type 304L stainless steel tensile specimens.
Specimens were tested at the irradiation temperature of 50-164°C. Less than 1 dpa of exposure reduced the uniform elongation of Alloy 718 (precipitation hardened) and mod 9Cr-lMo to less than 2%. Approximately 4 dpa of exposure was required to reduce the uniform elongation of the austenitic stainless steels (304L and 316L) to less than 2%. The yield stress of the austenitic steels increased to more than twice its non-irradiated value after less than 1 dpa. These results are discussed and compared with results of similar materials irradiated in fission reactor environments.