Sandwich, double-reference-wave, holographic, phase-shift interferometry

Phase-shift interferometry has provided a straightforward method for converting interferograms to phase maps. Unfortunately, some of the most powerful pulsed holographic interferometry techniquesare generally not compatible with phase-shift interferometry. One solution is to employ two reference waves, one for each of the two object waves to be interfered, that can be phase stepped during reconstruction. Practical aberration and alignment problems render this approach difficult. A simple method that employs a second hologram, sandwiched with the first, which produces the required two reference waves during reconstruction, is presented. The process compensates for both chromatic and geometric aberrations that otherwise render the phase-shift method unusable.     

A stable,wideband tunable,near transform-limited,graphene-mode-locked,ultrafast laser

We report an ultrafast laser mode-locked with a graphene saturable absorber. The linear dispersions of the Dirac electrons in graphene enable wideband tunability. We get ∼1 ps pulses, tunable between 1525 and 1559 nm, with stable mode-locking, insensitive to environmental perturbations.     

Phase relationships in the ternary systems (V,Cr, Mo,W, Mn,Re)-Al-N

Phase equilibria in the ternary systems of aluminum and nitrogen with vanadium, chromium, molybdenum, tungsten, manganese and rhenium are investigated by X-ray diffraction of sintered alloys. No ternary phase is observed. AIN does not show solubility for these metals, and coexists either with the solid solution of these metals with aluminium (in the case of vanadium, chromium and manganese) or with the pure metal (for molybdenum, tungsten and rhenium). Isothermal sections are presented for 1073 K (Mn-Al-N), 1273 K (V-Al-N, Cr-Al-N, Mn-Al-N and Re-Al-N), 1573 K (V-Al-N) and 1773 K (Mo-Al-N, W-Al-N and Re-Al-N).     

Elastic properties of thorium ceramics ThX (X = C,N, O,P, As,Sb, S,Se)

The elastic constants (C ₁₁, C ₁₂, and C ₄₄) of all the known cubic binary phases of thorium with non-metals, ThX (X = C, N, O, P, As, Sb, S, Se), have been calculated using the full-potential linearized augmented plane wave (FLAPW) method with an exchange-correlation potential in the generalized gradient approximation (GGA). Numerical estimates of elastic parameters of the corresponding polycrystalline ceramics (bulk compression modulus, shear modulus, Young’s modulus, Poisson’s ratio, and Lamé’s coefficients) are obtained and analyzed for the first time.     

Electrospray ionization mass spectrometry of tetracycline, oxytetracycline, chlorotetracycline, minocycline, and methacycline

The effects of mobile-phase additives and analyte concentration on electrospray ionization mass spectra of a series of tetracyclines were investigated in both positive and negative ion modes. Only [M + H](+) and [M - H](-) ions were observed. The greatest sensitivity as [M + H](+) ions was obtained with 1% acetic acid and the greatest sensitivity as [M - H](-) ions was obtained using 50 mM ammonium hydroxide. Sensitivities in the positive ion mode were greater than those in the negative ion mode. The sensitivity as [M + H](+) showed no systematic variation with pH; however, the sensitivity as [M - H](-) did increase with increasing pH. A larger linear range was observed for [M - H](-) than for [M + H](+) ions. Both [M + Na](+) and [M + H](+) ions were observed with 0.5 mM sodium acetate and sodium iodide, but no adduct ions were observed with ammonium acetate. Some M(2)H(+) ions were observed at higher concentrations. Cluster ions, Na(NaOAc)(n)(+) or Na(NaI)(n)(+), but no sample ions were observed using 5 mM salts. The data suggest that mechanisms in addition to solution ionization are involved in the formation of the ESI sample ions. The utility of mobile phases containing 1% HOAc or 50 mM NH(4)OH was demonstrated for chromatographic separations.     

Theory of curved, clamped, piezoelectric film, air-borne transducers

Differential equations in the cylindrical coordinate system have been solved to calculate vibration mode of a curved, clamped, piezoelectric multilayer film. Type I has two clamps at straight ends with uniform film curvature, and Type II has the same two clamps with nonuniform curvature in which the radii are different for the central region and for side regions. The solutions include a uniform displacement term, flexural waves with sinusoidal terms, and a hyperbolic cosine term. By numerical computations, the vibration modes and frequency response of displacement are shown, as are various transducer performances. Mechanical losses of the layer materials were taken as complex Young's moduli with Q values assumed to be constant with frequency. Numerical calculations for 28-/spl mu/m PVDF with 25-/spl mu/m polyester enforcement have shown that (1) the resonance frequency is not necessarily proportional to the inverse of curvature radius as classical theory describes, and, furthermore, resonance diminishes for a certain range of radii, forming a stop band; (2) a back air cavity thinner than 150 /spl mu/m significantly increases the resonance frequency; (3) Type II generates much higher output pressure than Type I; (4) receiver sensitivities for Type I and Type II are not much different; and (5) the effect of radiation impedance is small leading to /spl sim/7% output reduction.     

Dry Autoclaving for the Nanofabrication of Sulfides,Selenides, Borides,Phosphides, Nitrides,Carbides, and Oxides

This review compiles various nanostructures fabricated by a distinct “dry autoclaving” approach, where the chemical reactions are carried out without solvents; above the dissociation temperature of the chemical precursor(s) at elevated temperature in a closed reactor. The diversity to fabricate carbides (SiC, Mo₂C, WC), oxides (VOx‐C, ZnO, Eu₂O₃, Fe₃O₄, MoO₂), hexaborides (LaB₆, CeB₆, NdB₆, SmB₆, EuB₆, GdB₆), nitrides (TiN, NbN, TaN), phosphides (PtP₂, WP), sulfides (ZnS, FeS/C, SnS/C, WS₂, WS₂/C), and selenides (Zn_1‐xMn_xSe/C, Cd_1‐xMn_xSe/C), with various shapes and sizes is accounted with plausible applications. This unique single‐step, solvent‐free synthetic process opens up a new route in the growing nanomaterials science; owing to its considerable advantages on the existing approaches.     

Dust explosions-cases, causes, consequences, and control

Dust explosions pose the most serious and widespread of explosion hazards in the process industry alongside vapour cloud explosions (VCE) and boiling liquid expanding vapour explosions (BLEVE). Dust explosions almost always lead to serious financial losses in terms of damage to facilities and down time. They also often cause serious injuries to personnel, and fatalities. We present the gist of the dust explosion state-of-the-art. Illustrative case studies and past accident analyses reflect the high frequency, geographic spread, and damage potential of dust explosions across the world. The sources and triggers of dust explosions, and the measures with which different factors associated with dust explosions can be quantified are reviewed alongside dust explosion mechanism. The rest of the review is focused on the ways available to prevent dust explosion, and on cushioning the impact of a dust explosion by venting when the accident does take place.     

Sustainability: ecological, social, economic, technological, and systems perspectives

Sustainability is generally associated with a definition by the World Commission on Environment and Development, 1987: "... development that meets the needs of the present without compromising the ability of future generations to meet their own needs ..." However, there is no mathematical theory embodying these concepts, although one would be immensely valuable in humanity's efforts to manage the environment. The concept of sustainability applies to integrated systems comprising humans and the rest of nature; the structures and operation of the human component (society, economy, law, etc.) must be such that they reinforce the persistence of the structures and operation of the natural component (ecosystem trophic linkages, biodiversity, biogeochemical cycles, etc.). One of the challenges of sustainability research lies in linking measures of ecosystem functioning to the structure and operation of the associated social system. We review the nature of this complex system including its ecological, social, economic, and technological aspects, and propose an approach to assessing sustainability based on Information Theory that bridges the natural and human systems. These principles are then illustrated using a model system with an ecological food web linked to a rudimentary social system. This work is part of the efforts of a larger multidisciplinary group at the U.S. Environmental Protection Agency's National Risk Management Research Laboratory.     

Synthesis of New Pb-based 1222 Layered Cuprates in the (Pb,S)Sr2(RE,Ce)2Cu2O z (RE=Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, and Y) System

A new family of the Pb-based layered cuprate with the 1222 structure has been synthesized in the (Pb,S)Sr₂(RE,Ce)₂Cu₂O _z (RE=Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, and Y) system. The almost-single phase samples are obtained for x=0.25 and y=1.0 in the composition of (Pb_1?x S _x )Sr₂(RE_2?y Ce _y )Cu₂O _z . Each of the samples has the crystal structure with a tetragonal symmetry. Both of the lattice parameters a and c are decreasing with the decrease of the ionic radius of RE element. Among these samples, the sample with RE=Er has the smallest resistivity in the whole temperature range and the slope of the resistivity versus temperature is the most gentle. Despite annealing under O₂ atmosphere at high-pressure of 121 atm, this sample is a semiconductor with the transport process characteristics of three-dimensional variable range hopping conduction. Then the samples of RE=Er with smaller y are investigated for the composition of (Pb_0.75S_0.25)Sr₂(RE_2?y Ce _y )Cu₂O _z , the sample with y=0.4 is found to show an onset of resistivity drop phenomenon at about 11 K with the decrease of temperature. Moreover, we also discover that the samples of RE=Ho with y=0.4 show an onset of the resistivity dropping at over 20 K and zero resistivity at 13 K. From these results, the present (Pb_0.75S_0.25)Sr₂(RE_2?y Ce _y )Cu₂O _z system is considered to be a new family of the Pb-based superconducting cuprates with the 1222 structure.     

Investigation of Transport Properties of Some Superconductor Nickel-Based Antiperovskite XNNi<Subscript>3</Subscript> (X = Mg,Al, Cu,Zn, Ga,Ag, Cd,In, Sn,Sb, Pt and Pb)

We report, in this work, a theoretical study of electronic and transport (thermoelectric) properties of some superconductor nickel-based antiperovskite XNNi₃ (X = Mg, Al, Cu, Zn, Ga, Ag, Cd, In, Sn, Sb, Pt and Pb) using first-principles calculations with the full-potential linearized augmented plane wave (FPLAPW) method based on the density functional theory (DFT) as implemented in the WIEN2k package. Electronic properties are calculated and show that the studied materials are of metallic type which is in good agreement with experimental data. The Seebeck coefficient, thermal conductivity, electrical conductivity and figure of merit were reported. The results obtained show that the zinc (Zn) and silver (Ag) materials are characterized by a high value of the figure of merit at room temperature (300 K) which is respectively 0.86 and 1.02 in a p-type region. In the case of the transition metals, the maximum values of S increase in going from the Pt atom to the Zn atom and then decrease for the Cd atom. Furthermore, the Wiedemann–Franz law which states that the ratio of thermal to electrical conductivity for metals is constant is well verified in this work. The electric conductivity values are almost invariant with the temperature except for the case of MgNNi₃ and AgNNi₃ compounds in which it increases with T slightly. So, the superconducting materials based on silver and zinc are the best for the thermoelectric applications at room temperature due to the very important value of the factor of merit and the Seebeck coefficient obtained.     

Fallgeschichte, Historia, Klassifikation

What was classification as it first took modern form in the eighteenth century, how did it work, and how did it relate to earlier describing and ordering? We offer new answers to these questions by considering an example less well known than that of botany or zoology, namely medicine, and by reconstructing practice on paper. The first and best-known disease classification is the “nosology” of the Montpellier physician François Boissier de Sauvages de Lacroix. Its several editions, we show, were less products than process: published tools for building a classification system. The disorder of a hitherto unstudied notebook that Boissier de Sauvages kept throughout this process provided a way of breaking with the topical order of earlier physicians’ humanistic commonplace books of disease observation while sustaining the paper practices those earlier physicians—and Sauvages himself as a student—had used to order disease. This suggests a different picture of historical change than that of a scholarly world of ordered words giving way to a scientific one of ordered things. Classification, in the case of Sauvages’ nosology, arose through an incomplete break with, and intensified practice of, a past way of ordering the described world. The humanist paper practice that had made observationes, differently applied, now made species. Classification into genera and species by similarity and difference, which Sauvages’ nosology shared with botany, was an algorithm of paper and ink practice—in its operation more machine-like than humanist textual practice yet in its effects more creative and re-creative of categories and questions of relationship. Thus a new empiricism of generalizations (species) arose out of the older, Renaissance empiricism of particulars (observations, facts).     

Seamless, axially aligned, fiber tubes, meshes, microbundles and gradient biomaterial constructs

A new electrospinning apparatus was developed to generate nanofibrous materials with improved organizational control. The system functions by oscillating the deposition signal (ODS) of multiple collectors, allowing significantly improved nanofiber control by manipulating the electric field which drives the electrospinning process. Other electrospinning techniques designed to impart deposited fiber organizational control, such as rotating mandrels or parallel collector systems, do not generate seamless constructs with high quality alignment in sizes large enough for medical devices. In contrast, the ODS collection system produces deposited fiber networks with highly pure alignment in a variety of forms and sizes, including flat (8?×?8?cm²), tubular (1.3?cm diameter), or rope-like microbundle (45?μm diameter) samples. Additionally, the mechanism of our technique allows for scale-up beyond these dimensions. The ODS collection system produced 81.6?% of fibers aligned within 5° of the axial direction, nearly a four-fold improvement over the rotating mandrel technique. The meshes produced from the 9?% (w/v) fibroin/PEO blend demonstrated significant mechanical anisotropy due to the fiber alignment. In 37?°C PBS, aligned samples produced an ultimate tensile strength of 16.47?±?1.18?MPa, a Young’s modulus of 37.33?MPa, and a yield strength of 7.79?±?1.13?MPa. The material was 300?% stiffer when extended in the direction of fiber alignment and required 20 times the amount of force to be deformed, compared to aligned meshes extended perpendicular to the fiber direction. The ODS technique could be applied to any electrospinnable polymer to overcome the more limited uniformity and induced mechanical strain of rotating mandrel techniques, and greatly surpasses the limited length of standard parallel collector techniques.     

Efficient,high photostability,high brightness,co-polymer solid state dye lasers

Abstract

We report an investigation of the laser beam quality, efficiency and photostability of rhodamine 590 solid state dye lasers with hosts based upon 2-hydroxyethylmethacrylate and methylmethacrylate P(HEMA:MMA) co-polymers and modified methylmethacrylate (MPMMA) polymers with ethanol and dimethylsulphoxide additives. Highest efficiencies were obtained with MPMMA, with slope efficiencies of up to 44% (corresponding to 61% optical-optical conversion) measured for ethanolic MPMMA. P(HEMA:MMA) hosts gave superior photostability, with the highest normalized photostability of 240 GJ mol^?1 obtained for a P(HEMA:MMA) 1:1 rod. A simple resonator has been used to compensate the effects of thermal lensing and pump mode-mismatch, resulting in optimized beam quality for MPMMA lasers.     

Alan Pritsker's multifaceted career: theory, practice, education, entrepreneurship, and service

In this lead article for the special issue of HE Transactions honoring Alan Pritsker, we summarize Alan' s most significant contributions to the fields of industrial engineering and operations research, with special emphasis on his contributions to computer simulation.     

Raman spectroscopy of amorphous, nanostructured, diamond-like carbon, and nanodiamond

Raman spectroscopy is a standard characterization technique for any carbon system. Here we review the Raman spectra of amorphous, nanostructured, diamond-like carbon and nanodiamond. We show how to use resonant Raman spectroscopy to determine structure and composition of carbon films with and without nitrogen. The measured spectra change with varying excitation energy. By visible and ultraviolet excitation measurements, the G peak dispersion can be derived and correlated with key parameters, such as density, sp(3) content, elastic constants and chemical composition. We then discuss the assignment of the peaks at 1150 and 1480 cm(-1) often observed in nanodiamond. We review the resonant Raman, isotope substitution and annealing experiments, which lead to the assignment of these peaks to trans-polyacetylene.     

High-Resolution Elemental Bioimaging of Ca, Mn, Fe, Co, Cu, and Zn Employing LA-ICP-MS and Hydrogen Reaction Gas

Imaging of trace metal distribution in tissue sections by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) is typically performed using spatial resolutions of 30 μm(2) and above. Higher resolution imaging is desirable for many biological applications in order to approach the dimensions of a single cell. The limiting factor for increasing resolution is sensitivity, where signal-to-noise ratios are poor due to inherent background spectral interferences and reduced sample volume with decreasing laser beam diameter. Several prominent spectral interferences are present for a number of biologically relevant isotopes, including the (40)Ar(16)O(+) spectral interference on (56)Fe(+). We examined if H(2) as a reaction gas could improve the analytical performance of imaging experiments for a range of masses with spectral interferences. At low (<1 mL min(-1)) H(2) flow rates, greater spectral interference due to H(+) adducts was observed for (55)Mn, (57)Fe, and (59)Co. At higher flow rates of up to 3 mL H(2) per minute, the spectral interferences were reduced leading to improvement in limits of analysis for masses with O- and N-based polyatomic interferences. Enhanced sensitivity with the reaction cell allowed construction of high resolution (6 μm(2)) imaging of (56)Fe in the mouse brain that approached the dimensions of single cells.     

Phase relationships in systems based on Y,Gd, Mn,Ti, and U oxides with addition of Ca,Al, and Fe oxides

Samples of titanate-based ceramics with Y, Gd, Mn, U, Ca, Al, and Fe oxides, which are of interest as hosts for immobilization of radioactive waste containing lanthanides, actinides, and corrosion products, were prepared by cold pressing, sintering, and fusion. The major components of the ceramics are phases of the structure derived from the fluorite structure (pyrochlore, “murataite,” cubic oxide with fluorite lattice type), and also brannerite. Introduction of Al and Fe oxides (corosion products) leads to the formation of additional phases of the perovskite and/or crichtonite structure.     

The vapor pressure of indium,silver, gallium,copper, tin,and gold between 0.1 and 3.0 bar

The vapor pressure of several liquid metals was measured using a method based on the gas-controlled heat pipe. Small samples of the test material were placed in a tungsten tube and heated to temperatures above 2900 K. The vapor pressure was measured using a gas-buffered pressure transducer and the vapor temperature was inferred from the tube surface temperature, which was measured with an optical pyrometer. Most of the tests were terminated by the failure of the containment tube. The measured pressures agree well with those calculated by thermodynamic methods from data at lower temperatures.