bluuebunny/crossref_metadata_2025 huggingface dataset:
The Behavior of Nickel and Monel in Outdoor Atmospheres
Authors: Wesley W A
Published: September 2009

The present state of knowledge regarding the atmospheric corrosion of nickel and monel is summarized. The mechanism of corrosion is described with respect to both the fogging and later stages of weathering. With these metals, the effect of shelter from the rinsing action of rain is not pronounced. It seems probable that the corrosion-time relationship is practically linear. Of the various methods for quantitative determination of the amount of corrosion in field tests, measurements of loss in weight are shown to be most expedient for high-nickel alloys. A marked beneficial effect of chromium alloyed in nickel is observed. For the convenience of the design engineer, the available weight-loss data are presented graphically together with a discussion of the engineering significance of all the assembled information.
Tracking Troubles in Atmospheric Corrosion Testing
Authors: Olmstead P S , Campbell W E , Romig H G
Published: September 2009

In 1938 a subgroup of Subcommittee VI on Atmospheric Corrosion of A.S.T.M. Committee B-3 on Corrosion of Non-Ferrous Metals and Alloys was set up to decide whether sufficient returns to justify the effort expended were being obtained from the statistical calculations being made as part of the Subcommittee VI program. This subgroup reported that some statistical calculations were still justified but that trouble (due to lack of statistical control in the test data) had been encountered which required further study. Subsequently, Subcommittee V on Statistical Analysis and Planning was established. The objectives of this subcommittee were (1) to continue the studies of the earlier group, (2) to provide aid to other subcommittees in the planning of corrosion tests, and (3) to aim at the compilation of a booklet or series of papers on the application of statistics to corrosion testing which could be readily understood by corrosion engineers.
Glass Adhesives
Authors: Moser Frank
Published: September 2009

Adhesives for glass surfaces are classified according to chemical type. The more promising ones for bonding glass are the modified phenolics, the butadiene acrylonitrile vinyl copolymer, and butadiene acrylonitrile polyvinyl butyral. Vinyl phenol, polyvinyl acetate, the celluloses, acrylates, rubber latex, and cyclo-rubber types give fair adhesion for room temperature exposure but deteriorate quite rapidly under moist conditions. Glass-metal adhesives require good weathering qualities but must also be tested for temperature cycling in order to eliminate the more brittle types which induce the strains responsible for glass failure due to differences in thermal expansion. Thus, a well-rounded testing program is very beneficial in selecting adhesives for various fabrications.
Nondestructive Determination of Mechanical Properties and Deterioration of Adhesives
Authors: Dietz Albert G H , Bockstruck Herman N , Epstein George
Published: September 2009

Engineering adhesives are assuming increasing importance in structures of various kinds. Their mechanical properties and their deterioration under adverse conditionsare, consequently, factors of considerable importance. A program of research has therefore been sponsored by Army Ordnance to investigate nonbiological factors leading to the deterioration of such adhesives, particularly in metal to metal bonds.
Summary
Authors: Platow R C
Published: September 2009

We have just listened to five very excellent technical papers. I have been given the task of trying to summarize what has been said. For many reasons this is a difficult job, principally because it is difficult to rigorously comment on such controversial subjects without the benefit of substantiating laboratory evidence.
An Absolute Method of X-ray Fluorescence Analysis Applied to Stainless Steels
Authors: Noakes Gordon E
Published: September 2009

Analytical methods employing X-ray fluorescent radiation have been restricted in general to either a narrow range of element concentrations in multiple component alloys (1, 2, 3)2 or to binary alloys (4). It has been a supposed requirement that the linear absorption coefficient of the matrix be kept constant for a particular element before an analysis using a calibration curve could be made. These restrictions have imposed limitations on the analysis of alloys to such an extent that the approximate percentage composition must be known for a sample before quantitative analysis can be made by X-ray fluorescence.
Resistance of Aluminum-Base Alloys to 20-Year Atmospheric Exposure
Authors: Walton C. J. , King W.
Published: September 2009

This paper comprises a discussion of the 20-yr atmospheric weathering data obtained on wrought aluminum-base alloys included in an investigation on non-ferrous metals sponsored by Committee B-3 of the American Society for Testing Materials. The pertinent data obtained after exposure periods of 1, 3, 6, 10 and 20 yr have been tabulated and also arranged graphically to illustrate characteristics of specific interest, such as (1) effect of natural aging on the tensile strength of specimens stored indoors for 20 years; (2) rating of the corrosivity of the seven atmospheric conditions employed; and (3) the rate of weathering of the five aluminum alloys. These important data have been further enhanced by correlating them with equally long-time data obtained by the Aluminum Research Laboratories on similar alloys in other atmospheric environments, and on newer aluminum alloys which now complement or supersede the alloys which had been in the ASTM investigation.
The Atmospheric Corrosion of Copper-Results of 20-Year Tests
Authors: Thompson D. H. , Tracy A. W. , Freeman J. R.
Published: September 2009

Eleven brands of copper, in the form of sheet and wire, have been exposed for 20 yr to four outdoor atmospheres in Connecticut. The effect of corrosion has been evaluated by loss in weight, loss in strength, and gain in electrical resistance. Some of the results have been examined by applying an analysis of variance. The mean corrosion rate was found to be on the order of 50 × 10−6 in. per yr. While the differences were of no practical significance, the purest coppers corroded least, and the arsenical coppers corroded most.
D 513 - 57 Standard Methods of Test for Total Carbon Dioxide and Calculation of the Carbonate and Bicarbonate ions in Industrial Water
Authors: Committee D-19
Published: September 2009

(a) These methods cover the determination of total carbon dioxide, both dissolved and chemically combined, in industrial water. The methods also cover the calculation of the concentrations of carbonic acid, bicarbonate ion, and carbonate ion. Two methods are given, as follows: Sections Referee Method 5 to 12 Non-Referee Method 13 to 20 (b) The referee method provides the maximum accuracy and freedom from interference. The non-referee method requires less apparatus, but is less precise and more liable to interference problems.
D 515 - 58 T Tentative Methods of Test for Phosphate in Industrial Water
Authors: Committee D-19
Published: September 2009

(a) These methods cover the determination of dissolved phosphates in industrial water. The following four methods are included: Sections Referee Method (Gravimetric Method) 5 to 11 Non-Referee Method A (Volumetric Method) 12 to 18 Non-Referee Method B (Colorimetric Method) 19 to 27 Non-Referee Method C (Colorimetric Method) 28 to 36 (b) All of the methods are based on reactions that are specific for the orthophosphate ion. Preliminary treatment is included for removal of color and turbidity, and heating in the presence of strong acids in the gravimetric and volumetric methods is included to convert most polyphosphates to the ortho form. As described, the gravimetric and volumetric methods determine all dissolved phosphates that can be dissolved and converted to the ortho form by the prescribed treatment. The colorimetric methods determine dissolved orthophosphate only.
D 596 - 58 Standard Method of Reporting Results of Analysis of Industrial Water and Industrial Waste Water
Authors: Committee D-19
Published: September 2009

This method presents recommendations as to the nature, extent, and form in which the results of analysis of industrial water and industrial waste water should be presented. All analyses are to be made in accordance with the methods of test of the American Society for Testing Materials, unless otherwise specified. Note 1.—While various other methods of reporting the analysis of industrial water and industrial waste water are in use, this method is intended as a rational and comprehensive practice for general application. For use in specific industries or individual cases, hypothetical combinations of certain ions may be useful and desirable.
D 807 - 52 Standard Method of Corrosivity Test of Industrial Water (USBM Embrittlement Detector Method)
Authors: Committee D-19
Published: September 2009

This method, known as the embrittlement-detector test, covers the apparatus and procedure for determining the embrittling or nonembrittling characteristics of the water in an operating boiler. The interpretation of the results shall be restricted to the limits set forth in Section 12. Note 1.—The embrittlement detector was designed to reproduce closely the conditions existing in an actual boiler seam. It is considered probable that the individual conditions of leakage, concentration, and stress in the boiler seam can equal those in the detector. The essential difference between the detector and the boiler is that the former is so constructed and operated that these three major factors act simultaneously, continuously, and under the most favorable circumstances to produce cracking; whereas, in the boiler the three factors are brought together only under unique circumstances. Furthermore, in the detector any cracking is produced in a small test surface that can be inspected thoroughly, while the susceptible areas in a boiler are large and can be inspected only with difficulty. In these respects the embrittlement detector provides an accelerated test of the fourt condition necessary for embrittlement, the embrittling nature of the boiler water. Note 2.—Cracks in a specimen after being subjected to this test indicate that the boiler water can cause embrittlement cracking, but not that the boiler in question necessarily has cracked or will crack.
D 933 - 50 Standard Method of Reporting Results of Examination and Analysis of Water-Formed Deposits
Authors: Committee D-19
Published: September 2009

This method describes the manner in which the results of examination and analysis for inorganic constituents of deposits formed from industrial waters are to be reported. Note 1.—All analyses are to be made in accordance with the methods of test of the American Society for Testing Materials, unless otherwise specified. Note 2.—While various other methods of reporting the analysis of water-formed deposits are in use, this method is intended as a rational and comprehensive practice for general application. For use in specific industries or individual cases, molecular combinations may be useful and desirable.
D 993 - 58 Standard Methods of Test for Sulfate-Reducing Bacteria in Industrial Water and Water Formed Deposits
Authors: Committee D-19
Published: September 2009

(a) These methods are intended for the detection of the presence of sulfatereducing bacteria when present in deposits or industrial water samples and for estimation of the number of bacteria present. Two methods are given, as follows: Sections Referee Method 5 to 10, Non-Referee Method 11 to 16. (b) The referee method covers the preferred procedure for the detection and estimation of sulfate-reducing bacteria in industrial water samples. The non-referee method covers a procedure of greater simplicity and lesser precision than the referee method.
D 1067 - 57 T Tentative Methods of Test for Acidity and Basicity (Alkalinity) in Industrial Water and Industrial Waste Water
Authors: Committee D-19
Published: September 2009

(a) These methods cover the determination of acidity and basicity (alkalinity) in industrial water and industrial waste water. Procedures are given for the determination of a titration curve that will define the inflection points and the buffering capacity, and for the determination of acidity or basicity (alkalinity) to a predesignated pH end point. Three methods are given, as follows: Sections Referee Method (Electrometric Titration) 5 to 13, Non-Referee Method A (Color-Comparison Titration) 14 to 21, Non-Referee Method B (Color-Change Titration) 22 to 29. (b) The Referee Method is electrometric and is the most precise and accurate of the three methods. Non-Referee Method A depends on the matching of colors with those of buffered standards and is satisfactory for routine control use, provided the sample contains no buffering materials at the end point. Non-Referee Method B depends upon the color change of an indicator during the course of a titration and is suitable for routine use, providing the sample contains no buffering materials at the end point.
D 1068 - 55 T Tentative Methods of Test for Iron in Industrial Water and Industrial Waste Water
Authors: Committee D-19
Published: September 2009

These methods cover the determination of iron in industrial water and in industrial waste water. Procedures are given for determining total iron, dissolved iron, and ferrous iron. Suspended iron may be calculated from the total iron and soluble iron determinations. Two methods are given as follows: Sections Referee Method 6 to 15, Non-Referee Method 16 to 25.
D 1069 - 58 Standard Methods of Test for Suspended and Dissolved Matter (Suspended and Dissolved Solids) in Industrial Water and Industrial Waste Water
Authors: Committee D-19
Published: September 2009

(a) These methods describe procedures for the determination of suspended and dissolved matter in industrial water of all types, including industrial waste water. They may be applied for the determination and differentiation of total, suspended, dissolved, ignited, and volatile matter, including solids and nonaqueous liquids which are settleable, nonsettleable, or floating. The methods are not intended for the determination of materials normally classified as “oily matter,” such as vegetable oils, animal oils, and petroleum oils that are volatile at the boiling point of water or extractable with organic solvents. (b) These methods are divided according to specific application as follows: Sections Method A (Suspended and Dissolved Matter (Suspended and Dissolved Solids) in High-Purity Industrial Water) 6 to 12, Method B (Suspended and Dissolved Matter (Suspended and Dissolved Solids) in Low-Purity Industrial Water and Industrial Waste Water) 13 to 19.
D 1193 - 56 Standard Specifications for Reagent Water
Authors: Committee D-19
Published: September 2009

(a) These specifications cover requirements for water suitable for use in methods of chemical analysis and physical testing. Two grades of reagent water are specified: Referee Reagent Water Non-Referee Reagent Water (b) Reagent water may be prepared by distillation, by condensation of commerical steam, or by use of a suitable demineralization (cation and anion removal) process. (c) Referee reagent water is suitable for operations in referee analysis. Non-referee reagent water is suitable for use in general laboratory testing.
D 1256 - 59 T Tentative Scheme for Analysis of Industrial Water and Industrial Waste Water
Authors: Committee D-19
Published: September 2009

(a) This is a systematic scheme for the examination of industrial water and industrial waste water. The order of application of methods for chemical and physical measurements permits the determination of existing constituents and properties in logical sequence. (b) This scheme is intended to aid the water analyst in choosing an analytical course that he can follow to determine one or all of the constituents or properties of industrial water. The outline indicates by general groupings of water constituents and properties the general procedures that must be followed in obtaining the sample, depending upon the information desired. By further subgrouping it also indicates what general precautions must be observed in preserving the character of the sample with respect to the desired analysis. (c) There are four schematic outlines. The first (Fig. 1) shows the general schematic relationship of the principal groups of samples. The remaining three (Tables I to III) list the constituents and properties that can be determined on each group of samples. (d) The constituents or properties in each group appear in alphabetical order, where possible. Where a simple, acceptable test for a given constituent or property is desirable in providing information useful in subsequent analyses to be performed on a sample, it is indicated by an asterisk. For example, a colorimetric silica determination would indicate the volume of sample that would contain silicon compounds equivalent to at least 10 mg of SiO2, as specified in the referee method for SiO2 in the Methods of Test for Silica in Industrial Water and Industrial Waste Water (ASTM Designation: D 859). Completion of such a simple preliminary test would save considerable time. (e) Each constituent or property of a sample group that is listed without indentation from the margin (see Table I to III) indicates that a separate portion is required for the analysis for that particular constituent. Where an analytical scheme is possible or desirable, and one or more constituents may be determined on a single sample by a scheme of successive analyses of filtrates or aliquots, the constituents determined in the scheme are indented in reference to the appropriate preceding constituent.
D 1428 - 56 T Tentative Methods of Test for Sodium and Potassium Ions in Industrial Water and Water-Formed Deposits by Flame Photometry
Authors: Committee D-19
Published: September 2009

(a) These methods cover the determination of sodium and potassium ions in industrial water and waterformed deposits, using both direct-measuring and internal-standard type flame photometers. A procedure for each type is included in these methods. The direct-intensity method is used for both types of instrument in the analysis of water of high purity. Three methods are given, as follows: Sections Method A. Analysis of Industrial Water 8 to 13 Method 1 Analysis of High-Purity 1 dustrial Water 14 to 19 Method C. Analysis of Water-Formed eposits 20 to 25 (b) N n-instrumental methods for sodium an potassium ions in industrial water are given in the Methods of Test for Sodium and Potassium in Industrial Water (ASTM Designation: D 1127).
D 1589 - 58 T Tentative Methods of Test for Dissolved Oxygen in Industrial Waste Water
Authors: Committee D-19
Published: September 2009

(a) These methods describe procedures for the determination of dissolved oxygen in industrial waste water in the presence of certain interfering substances. Common interfering substances which may occur in such water are nitrites, ferrous iron, organic material, sulfites, or other oxidizing or reducing substances. Provisions incorporated in this method will, in most cases, lessen the interference of such substances in the determination of dissolved oxygen. Four methods are given, as follows: Sections Alsterberg (Azide) Method 7 to 11 Rideal-Stewart Method 12 to 16 Pomeroy - Kirshman - Alsterberg Method 17 to 21 Polarographic Method 22 to 28 (b) Selection of the method to use for the dissolved oxygen determination will be determined by the nature of the sample and the type or types of interferences present. (1) The Alsterberg (azide) method is the most effective method for removing interference caused by nitrites. Nitrites are the most common interferences found in surface waters. This method can also be used in the absence of other interfering substances. (2) The Rideal-Stewart (permanganate) method is used only in the presence of ferrous iron and not in the presence of organic matter. (3) The Pomeroy-Kirshman-Alsterberg method is used for waters supersaturated with oxygen or those having a high organic content. (4) The polarographic method is suggested for certain industrial wastes, particularly where sulfites are present. This method is in an early stage of development and is provisionally recommended only for wastes after dilution with natural water by a factor of 4 to 100.
D 1591 - 58 T Tentative Method of Test for Effect of Water in Tubular Heat Exchangers
Authors: Committee D-19.
Published: September 2009

This method covers the determination of the tendency of an industrial water to cause corrosion or to form deposits when flowing through a metallic tube in a heat exchanger.
D 1690 - 59 T Tentative Method for Measurement of Gamma Radioactivity of Industrial Water and Industrial Waste Water
Authors: Committee D-19
Published: September 2009

(a) This method covers the measurement of gamma radioactivity of industrial water and industrial waste water. It is applicable to gamma emitters in the energy range above 0.1 Mev and in the concentration range of 10−2 to 10−5 microcuries per milliliter of radioactively homogeneous water. (b) The method can be used for either absolute or relative determinations. In tracer work, the results may be expressed by comparison with an initial concentration which is taken as 100 per cent. For radioassay it may be expressed in terms of a known isotopic standard if the radionuclides concerned are known or it may be expressed arbitrarily in terms of some other standard such as cesium-137. General information on radioactivity and measurement of radiation has been published.
E 70 - 52T Tentative Method for Determination of pH of Aqueous Solutions with the Glass Electrode
Authors: Committee E-1
Published: September 2009

This method covers the definition of pH and the apparatus and procedure for the electrometric measurement of pH values of aqueous solutions or extracts with the glass electrode. It does not deal with the manner in which the solutions or extracts are prepared.
Bibliographical Abstracts on Redeposition of Soil on Cotton Fabric
Authors: Kramer M. G. , Paitchel Howard , Tidridge W. A.
Published: September 2009

A task committee for the purpose of developing a method for measurement of deposition of soil onto fabric from aqueous detergent systems (laundering) was appointed in 1953 by A. M. Schwartz, chairman of Subcommittee T-5 of ASTM Committee D-12 on Soaps and Other Detergents. The first action of this task committee was to review the past literature to obtain information necessary for consolidation or revision of the best in current redeposition methods or for the development of a new method. It was believed that publication of a bibliography covering this literature review would be of benefit to detergent workers, particularly to those just entering the field, and this publication has resulted. The bibliography is patterned after “Metal Cleaning Bibliographical Abstracts.” The references, which are numbered consecutively, are listed by year and then by author. The abstracts in many cases were prepared from the original article and are slanted generally towards giving an indication of the contents that are pertinent to testing methods and theories. Reference is made to the abstract appearing in “Chemical Abstracts” whereever possible.
Equipment, Mode, and Location of Fractures and Associated Conditions
Authors: Denhard E. E.
Published: September 2009

The broad categories listed in Table I represent an attempt to classify the case histories according to the basic industries in which stress-corrosion cracking was thought to be most frequently associated. All case histories were used with the exception of Nos. 27, 28, and 72. Cases Nos. 27 and 28 were instances of cracking occurring as a result of molten metal attack, and No. 72 described a case in which cracking was expected but did not occur. Unfortunately, much of the data contained insufficient detail to classify the cases accurately other than under a “miscellaneous and unknown” heading. Cases which included heat exchangers or condensers, sterilizers, etc., which cracked on the water or steam side, but were not clearly associated with any particular industry, were included with the “heat generation” group.
The Mechanism of Stress-Corrosion Cracking of Austenitic Stainless Steels
Authors: Harwood Julius J.
Published: September 2009

The purpose of this discussion is to assess the state of our understanding concerning the factors and mechanism(s) which determine and control the susceptibility to stress-corrosion cracking of the austenitic stainless steels. The growing importance of this problem has led to a considerable amount of research, both in this country and abroad, aimed at delineating more specifically the environmental, compositional, and structural conditions involved and at elucidating the underlying mechanism for the cracking phenomenon. As a result of this research effort, a number of mechanisms have been proposed, but all appear to contain certain deficiencies in explaining certain of the characteristic features of the stress-corrosion cracking process; that is to say, unequivocal arguments cannot be presented in behalf of any of the proposed mechanisms. Possibly more to the point is the fact that few of the currently debated mechanisms have yielded critical clues which could lead to compositional or structural modifications of commercial materials to reduce or prevent the incidence of cracking. It is encouraging to note, however, that the more recent experimental evidence is developing a basis whereby critical type of experiments can be designed to differentiate clearly the mode of damage.
Mislocalization of Flashed and Stationary Visual Stimuli after Adaptation of Reactive and Scanning Saccades
Authors: Zimmermann Eckart , Lappe Markus
Published: September 2009

When we look around and register the location of visual objects, our oculomotor system continuously prepares targets for saccadic eye movements. The preparation of saccade targets may be directly involved in the perception of object location because modification of saccade amplitude by saccade adaptation leads to a distortion of the visual localization of briefly flashed spatial probes. Here, we investigated effects of adaptation on the localization of continuously visible objects. We compared adaptation-induced mislocalization of probes that were present for 20 ms during the saccade preparation period and of probes that were present for >1 s before saccade initiation. We studied the mislocalization of these probes for two different saccade types, reactive saccades to a suddenly appearing target and scanning saccades in the self-paced viewing of a stationary scene. Adaptation of reactive saccades induced mislocalization of flashed probes. Adaptation of scanning saccades induced in addition also mislocalization of stationary objects. The mislocalization occurred in the absence of visual landmarks and must therefore originate from the change in saccade motor parameters. After adaptation of one type of saccade, the saccade amplitude change and the mislocalization transferred only weakly to the other saccade type. Mislocalization of flashed and stationary probes thus followed the selectivity of saccade adaptation. Since the generation and adaptation of reactive and scanning saccades are known to involve partially different brain mechanisms, our results suggest that visual localization of objects in space is linked to saccade targeting at multiple sites in the brain.
Setting the Pace for Retinal Development: Environmental Enrichment Acts Through Insulin-Like Growth Factor 1 and Brain-Derived Neurotrophic Factor
Authors: Landi Silvia , Ciucci Francesca , Maffei Lamberto , Berardi Nicoletta , Cenni Maria Cristina
Published: September 2009

Environmental enrichment strongly affects visual system maturation both at retinal and cortical levels. Which molecular pathways are activated by an enriched environment (EE) to regulate visual system development has not been clarified. Here, we show that early [postnatal day 1 (P1) to P7] insulin-like growth factor 1 (IGF-1) injections in the eyes of non-EE rat pups mimic EE effects both in increasing BDNF levels in the retinal ganglion cell layer at P10 and in determining a more adult-like retinal acuity, assessed with pattern electroretinogram at P25. Blocking IGF-1 action in EE animals during the same early postnatal time window by injecting the IGF-1 receptor antagonist JB1 prevents EE effects both on BDNF expression and on retinal acuity maturation. Reducing BDNF expression in the retina of IGF-1-treated rats prevents IGF-1 effects on retinal acuity development. Finally, we show that tyrosine hydroxylase (TH) expression is increased in the retina of P10 EE and IGF-1-treated rats and that blocking TH expression in EE animals prevents EE from affecting retinal acuity development. Thus, early levels of IGF-1 play a key role in mediating EE effects on retinal development through an action that requires BDNF and involves dopaminergic amacrine cell network.
Presynaptically Expressed Long-Term Potentiation Increases Multivesicular Release at Parallel Fiber Synapses
Authors: Bender Vanessa A. , Pugh Jason R. , Jahr Craig E.
Published: September 2009

At a number of synapses, long-term potentiation (LTP) can be expressed by an increase in presynaptic strength, but it is unknown whether presynaptic LTP is expressed solely through an increase in the probability that a single vesicle is released or whether it can increase multivesicular release (MVR). Here, we show that presynaptic LTP decreases inhibition of AMPA receptor EPSCs by a low-affinity antagonist at parallel fiber–molecular layer interneuron (PF–MLI) synapses. This indicates that LTP induction results in larger glutamate concentration transients in the synaptic cleft, a result indicative of MVR, and suggests that MVR can be modified by long-term plasticity. A similar decrease in inhibition was observed when release probability (PR) was increased by forskolin, elevated extracellular Ca2+, and paired-pulse facilitation. Furthermore, we show that MVR may occur under baseline physiological conditions, as inhibition increased whenPRwas lowered by reducing extracellular Ca2+or by activating presynaptic adenosine receptors. These results suggest that at PF–MLI synapses, MVR occurs under control conditions and is increased whenPRis elevated by both short- and long-term plasticity mechanisms.
Dissociable Brain Structural Changes Associated with Predisposition, Resilience, and Disease Expression in Bipolar Disorder
Authors: Kempton Matthew J. , Haldane Morgan , Jogia Jigar , Grasby Paul M. , Collier David , Frangou Sophia
Published: September 2009

Genetic factors are important in the etiology of bipolar disorder (BD). However, first-degree relatives of BD patients are at risk for a number of psychiatric conditions, most commonly major depressive disorder (MDD), although the majority remain well. The purpose of the present study was to identify potential brain structural correlates for risk and resilience to mood disorders in patients with BD, type I (BD-I) and their relatives. Structural magnetic resonance imaging scans were acquired from 30 patients with BD-I, 50 of their first-degree relatives (28 had no Axis I disorder, while 14 had MDD) and 52 controls. We used voxel-based morphometry, implemented in SPM5 to identify group differences in regional gray matter volume. From the identified clusters, potential differences were further examined based on diagnostic status (BD-I patients, MDD relatives, healthy relatives, controls). Whole-brain voxel-based analysis identified group differences in the left hemisphere in the insula, cerebellum, and substantia nigra. Increased left insula volume was associated with genetic preposition to BD-I independent of clinical phenotype. In contrast, increased left substantia nigra volume was observed in those with the clinical phenotype of BD-I. Changes uniquely associated with the absence of a clinical diagnosis in BD relatives were observed in the left cerebellum. Our data suggest that in BD, genetic and phenotype-related influences on brain structure are dissociable; if replicated, these findings may help with early identification of high-risk individuals who are more likely to transition to syndromal states.
Doublecortin Associates with Microtubules Preferentially in Regions of the Axon Displaying Actin-Rich Protrusive Structures
Authors: Tint Irina , Jean Daphney , Baas Peter W. , Black Mark M.
Published: September 2009

Here we studied doublecortin (DCX) in cultured hippocampal and sympathetic neurons during axonal development. In both types of neurons, DCX is abundant in the growth cone, in which it primarily localizes with microtubules. Its abundance is lowest on microtubules in the neck region of the growth cone and highest on microtubules extending into the actin-rich lamellar regions. Interestingly, the microtubule polymer richest in DCX is also deficient in tau. In hippocampal neurons but not sympathetic neurons, discrete focal patches of microtubules rich in DCX and deficient in tau are present along the axonal shaft. Invariably, these patches have actin-rich protrusions resembling those of growth cones. Many of the DCX/actin filament patches exhibit vigorous protrusive activity and also undergo a proximal-to-distal redistribution within the axon at average rates ∼2 μm/min and thus closely resemble the growth-cone-like waves described by previous authors. Depletion of DCX using small interfering RNA had little effect on the appearance of the growth cone or on axonal growth in either type of neuron. However, DCX depletion significantly delayed collateral branching in hippocampal neurons and also significantly lowered the frequency of actin-rich patches along hippocampal axons. Branching by sympathetic neurons, which occurs by growth cone splitting, was not impaired by DCX depletion. These findings reveal a functional relationship between the DCX/actin filament patches and collateral branching. Based on the striking resemblance of these patches to growth cones, we discuss the possibility that they reflect a mechanism for locally boosting morphogenetic activity to facilitate axonal growth and collateral branching.
NMDA Receptor GluN2B (GluRε2/NR2B) Subunit Is Crucial for Channel Function, Postsynaptic Macromolecular Organization, and Actin Cytoskeleton at Hippocampal CA3 Synapses
Authors: Akashi Kaori , Kakizaki Toshikazu , Kamiya Haruyuki , Fukaya Masahiro , Yamasaki Miwako , Abe Manabu , Natsume Rie , Watanabe Masahiko , Sakimura Kenji
Published: September 2009

GluN2B (GluRε2/NR2B) subunit is involved in synapse development, synaptic plasticity, and cognitive function. However, its roles in synaptic expression and function of NMDA receptors (NMDARs) in the brain remain mostly unknown because of the neonatal lethality of global knock-out mice. To address this, we generated conditional knock-out mice, in which GluN2B was ablated exclusively in hippocampal CA3 pyramidal cells. By immunohistochemistry, GluN2B disappeared and GluN1 (GluRζ1/NR1) was moderately reduced, whereas GluN2A (GluRε1/NR2A) and postsynaptic density-95 (PSD-95) were unaltered in the mutant CA3. This was consistent with protein contents in the CA3 crude fraction: 9.6% of control level for GluN2B, 47.7% for GluN1, 90.6% for GluN2A, and 98.0% for PSD-95. Despite the remaining NMDARs, NMDAR-mediated currents and long-term potentiation were virtually lost at various CA3 synapses. Then, we compared synaptic NMDARs by postembedding immunogold electron microscopy and immunoblot using the PSD fraction. In the mutant CA3, GluN1 was severely reduced in both immunogold (20.6-23.6%) and immunoblot (24.6%), whereas GluN2A and PSD-95 were unchanged in immunogold but markedly reduced in the PSD fraction (51.4 and 36.5%, respectively), indicating increased detergent solubility of PSD molecules. No such increased solubility was observed for GluN2B in the CA3 of GluN2A-knock-out mice. Furthermore, significant decreases were found in the ratio of filamentous to globular actin (49.5%) and in the density of dendritic spines (76.2%). These findings suggest that GluN2B is critically involved in NMDAR channel function, organization of postsynaptic macromolecular complexes, formation or maintenance of dendritic spines, and regulation of the actin cytoskeleton.
Mori me non vult. Seneca and Pseudo-Quintilian's IVth Major Declamation
Authors: Pasetti Lucia
Published: September 2009

Riassunto

La IV Declamazione Maggiore pseudoquintilianea, un caso di mors voluntaria, è chiaramente influenzata da Seneca. Il rapporto intertestuale con Seneca filosofo può essere colto nei passaggi dell'argumentatio in cui il declamatore, che sostiene la necessità del suicidio, discute in generale il valore qualitativo del tempo, la vanità di una vita mal spesa, i vantaggi della mors opportuna. D'altra parte, il personaggio del figlio parricida presenta tratti tipicamente senecani: la percezione di una forza irrefrenabile che sorge dall'inconscio (nescioquid) e spinge il protagonista al delitto trova corrispondenze intertestuali nel Tieste e in altre tragedie di Seneca.
Copper Deposition Technology for Thru Silicon Via Formation Using Supercritical Carbon Dioxide Fluids Using a Flow Type Reaction System
Authors: Matsubara Masahiro , Kondoh Eiichi
Published: September 2009

A supercritical fluid is a high-pressure medium that possesses both high diffusivity and solvent capabilities. Metal thin films can be deposited in supercritical fluids from an organometallic compound (precursor) through thermochemical reactions. In the present study, we used a technique, aimed at applying to the fabrication of through-silicon vias (TSVs), where copper thin films were deposited in silicon microholes 10 μm in diameter and 350 μm in depth. The temperature and pressure were varied from 180°C to 280°C and 1 MPa to 20 MPa, respectively. The maximum coating depth decreased with deposition temperature, whereas a peak maximum of the depth was observed at around 10 MPa. The temperature and pressure dependences on the coating depth were numerically studied. On the basis of the analysis, a deposition program was modified as to elongate the coating depth.
High-Speed and Low-Power Performance of n-type InSb/InP and InAs/InP Core/Shell Nanowire Field Effect Transistors for CMOS Logic Applications
Authors: Khayer Mohammad Abul , Lake Roger K
Published: September 2009

The performance metrics of highly scaled n-type InSb/InP and InAs/InP core/shell nanowire (NW) field-effect transistors (FETs) are theoretically investigated using an 8-band k•p model and a semiclassical ballistic transport model. We present the ON-current, the intrinsic cut-off frequency, the gate-delay time, the power-delay product, and the energy-delay product of NWFETs with two NW diameters of 10 nm and 12 nm, which operate in the quantum capacitance limit. We compare the results to the numbers predicted or projected for other materials and dimensionalities and find good agreement. Within a source Fermi energy range of 0.1 – 0.3 eV for all devices, the ON-current varies from 7 – 58 μA, the intrinsic cut-off frequency ranges from 8 – 15 THz, the power-delay product varies from 2×10-20 – 9.7×10-19 J, the gate-delay time varies from 2 – 19 fs, and the energy-delay product ranges from 7×10-35 – 1×10-32 Js. These NWFETs, thus, provide both ultra-low power switching and high-speed.
Hydrothermal Synthesis of Zinc Oxide Nanowires on Kevlar using ALD and Sputtered ZnO Seed Layers
Authors: Conley John , Mason Ashley Diane , Waggoner Todd Jason , Smith Sean Weston , Gibbons Brady , Price David , Allman Derryl
Published: September 2009

Low temperature hydrothermal methods allow for growth of nanowires on novel substrates. We examine the impact of variations in chemical concentration, time, temperature, and seed layer on nanowire (NW) growth and crystallite formation. The majority of growth (NWs and crystallites) was found to occur within the first two hours. Lower Zn(NO3)2 concentrations produced a reduction in the undesired large crystallites, whereas hexamethylene tetramine (HMT) concentration did not largely impact crystallite density or nanowire morphology. Growth temperature appeared to impact NW diameter variation. Nanowires grow only on the ZnO seed layer and crystallites seem to attach preferentially to the bare Kevlar surface.
Thermocapillary Patterning of Nanoscale Polymer Films
Authors: Dietzel Mathias , Troian Sandra M
Published: September 2009

We investigate a method for non-contact patterning of molten polymer nanofilms based on thermocapillary modulation. Imposed thermal distributions along the surface of the film generate spatial gradients in surface tension. The resulting interfacial stresses are used to shape and mold nanofilms into 3D structures, which rapidly solidify when cooled to room temperature. Finite element simulations of the evolution of molten shapes illustrate how this technique can be used to fabricate features of different heights and separation distances in a single process step. These results provide useful guidelines for controlling proximity effects during evolution of adjacent structures.
Ion-beam Texturing at Nucleation – Manipulation of Crystallographic Orientation in Cubic Materials at the Nanometer Scale
Authors: Groves James , Hammond Robert , Marshall Ann , DePaula Raymond F , Stan Liliana , Clemens Bruce M
Published: September 2009

The use of an ion beam assist during the concurrent deposition of cubic materials can result in the growth of crystallographically oriented thin films. A model system, magnesium oxide (MgO), has been successfully used as a biaxially textured template film and develops texture in a different manner from that of other well-studied materials, like yttria-stablized zirconia. Here, we present data on the initial nucleation of biaxial texture in this model system using a novel in-situ quartz crystal microbalance (QCM) substrate combined with in-situ reflected high-energy electron diffraction (RHEED). Temporal correlation of mass uptake with the RHEED images of the growing surface can be used to elucidate the mechanism of texture development in these films. Experimental data shows that the initially polycrystalline MgO film develops biaxial crystallographic texture at a thickness of ˜2 nm, regardless of the ion-to-molecule ratio. RHEED images show the onset of texture occurs quickly and is somewhat analogous to a solid phase re-crystallization process with crystallite sizes of ˜3 to 4 nm. Imaging with transmission electron microscopy has corroborated these observations. Changes in the ion-to-molecule ratio can influence the crystallite size and affect the nucleation density of these films. Growth of these films on various substrates changes the sticking coefficient of the MgO and influences the nucleation density and film growth mode as well. This opens the possibility of using MgO and other materials to develop biaxially textured crystallites with a narrow, specified size distribution for nanoscale applications.
Quantitative Mechanical/Chemical Imaging of Bone from Dmp1 Null Mice
Authors: Yao Xiaomei , Bonewald Lynda F , Eick J David , Wang Yong
Published: September 2009

Dentin matrix protein 1 (DMP1) is an acidic noncollagenous protein which plays an important role in mineralized tissue formation. Dmp1 null adult mice are ricketic and osteomalacic and are a model for hypophosphatemic rickets [1]. Mutation in humans results is Autosomal Recessive Hypophosphatic Rickets [1]. The degree of bone mineralization significantly contributes to bone tissue mechanical properties, but precise relationships and interactions between chemical and mechanical variables are unknown. The objective of this study was to relate the differences in chemical properties in the Dmp1 wildtype (WT) and null (KO) mouse femoral cortical bone to their mechanical properties by using FTIR imaging and Scanning Acoustic Microscopy (SAM). Interactive mechanical (elastic modulus) and chemical images (i.e., mineral/matrix ratios) were generated from the same region of bone at a lateral resolution of ˜10 um. Mechanical analysis showed that elastic modulus, 75 percentile around 7.1 GPa, was ˜60% less in Dmp1 KO than that in WT, in which elastic modulus was 75 percentile around 15.2 GPa. The mineral-to-matrix ratios in Dmp1KO (4.96±1.63) were ˜2 times lower than that in Dmp1 WT (8.65±1.14). The mineral crystallinity and collagen crosslink ratios were not significantly different between KO and WT. Conclusions: The results relate the bone elastic modulus changes in Dmp1WT and KO mice with chemical changes within a specific bone site. These measurements provide a new tool for describing the variability of bone chemical and mechanical properties.
In vivo degradation behavior of PDC multiblock copolymers containing poly(para-dioxanone) hard segments and crystallizable poly(epsilon-caprolactone) switching segments
Authors: Hiebl Bernhard , Kratz Karl , Fuhrmann Rosemarie , Jung Friedrich , Lendlein Andres , Franke Ralf-Peter
Published: September 2009

The degradation behavior of biodegradable multiblock copolymers (PDC) containing poly(p-dioxanone) hard segments (PPDO) and crystallizable poly(epsilon-caprolactone) switching segments (PCL) synthesized via co-condensation of two oligomeric macrodiols with an aliphatic diisocyanate as junction unit was explored in in vivo and in vitro experiments. The in vitro experiments for enzymatic degradation resulted that the poly(epsilon-caprolactone) segments are degraded faster, than the poly(p-dioxanone) segments. During degradation the outer layer of the test specimen becomes porous. Finally non-soluble degradation products in form of particles were found at the surface. This observation is in good agreement with the in vivo studies, where the non-soluble degradation products in the periimplantary tissues showed a diameter of 1 – 3 micron.
Studies of the blue to red phase transition in polydiacetylene nanocomposites and blends
Authors: Patlolla Anitha , Wang Qi , Frenkel Anatoly , Zunino III James L , Skelton Donald R , Iqbal Zafar
Published: September 2009

The conjugated polymeric backbone of polydiacetylenes (PDAs), comprising of alternating ene-yne groups, undergo intriguing stress-, chemical- or temperature-induced chromatic phase transitions associated with the disruption of the backbone structure and shortening of the conjugation length. PDAs, such as polymerized 10, 12 pentacosadiynoic acids (PCDA), when incorporated with inorganic oxides form nanocomposites and uniform blends with polymers. Blends of poly-PCDA with polymers, such as polyvinyl alcohol, polyvinylidene fluoride and cellulose increase the blue to red transition temperature without affecting the irreversibility of the red phase. However, the addition of zinc oxide to pure poly-PCDA makes the red phase highly reversible and substantially increases the blue to red transition temperature. The addition of TiO2 to poly-PCDA on the other hand does not affect the irreversibility of the red phase and the chromatic transition temperature. In order to understand the atomic scale interactions associated with these changes in the chromatic transitions, we have investigated both the nanocomposites and polymer blends using Raman and Fourier-transform infrared spectroscopy, and extended X-ray absorption fine structure (EXAFS) measurements